Metal pipe connecting structure

Abstract

The utility model belongs to the technical field of stainless steel pipes, and particularly relates to a metal pipe connecting structure which comprises a stainless steel main pipe and a metal branch pipe welded on the stainless steel main pipe. The inner surface of the first expanding part is provided with first wire drawing grooves which are formed in the circumferential direction at intervals through the metal wire drawing technology and extend in the axial direction, and the end of the stainless steel main pipe is inserted into the expanding part of the stainless steel connector. The stainless steel pipe joint has the advantages that the stainless steel pipe joint can be welded in a welding furnace, the sealing performance is good, the welding flux cannot enter the welded stainless steel pipes, and the stainless steel pipe joint is used for welding connection between the stainless steel pipes.

Description

Technical Field

[0001] The utility model belongs to the technical field of conduit connection, and in particular relates to a metal pipe connection structure. Background Art

[0002] At present, the connection of flute-shaped tubes used in relevant equipment on the market generally adopts brass joints and copper sleeves to connect two stainless steel tubes. The disadvantages are: first, the brass joints, copper sleeves and stainless steel tubes cannot be put into the welding furnace for welding together; second, the stainless steel tubes are directly put into the welding furnace for welding, and the solder will flow into the stainless steel tubes to cause pollution and / or blockage; third, the welding at some positions is not sealed due to the loss of solder. Utility Model Content

[0003] The utility model aims to provide a stainless steel pipe connection structure which can be welded in a welding furnace, has good sealing performance and prevents solder from entering the welded stainless steel pipe.

[0004] The purpose of the utility model is to solve the problem as follows:

[0005] A metal pipe connection structure comprises a stainless steel main pipe and a metal branch pipe welded to the stainless steel main pipe, one end of the stainless steel joint is expanded to form a first expanded diameter portion, the inner surface of the first expanded diameter portion is provided with first drawing grooves which are circumferentially spaced and axially extended and made by a metal drawing process, the end of the stainless steel main pipe is inserted into the first expanded diameter portion of the stainless steel joint and solder or solder paste is added to weld and connect.

[0006] As a further optimization of the above technical solution, the middle portion of the stainless steel joint has the same inner diameter as that of the stainless steel main pipe.

[0007] As a further optimization of the above technical solution, the depth of the first wire drawing groove gradually increases from the middle of the inner wall of the first diameter expansion portion to the outside.

[0008] As a further optimization of the above technical solution, a second expansion neck is provided at the other end of the stainless steel main pipe.

[0009] As a further optimization of the above technical solution, an internal thread is provided on the inner wall of the second expansion neck portion.

[0010] As a further optimization of the above technical solution, a second wire drawing groove which is circumferentially spaced and axially extending and is made by a metal wire drawing process is provided in the middle of the inner wall of the second expansion neck portion.

[0011] As a further optimization of the above technical solution, the depth of the second wire drawing groove gradually increases from the inner side of the middle part of the inner wall of the second expansion neck portion to the outside.

[0012] As a further optimization of the above technical solution, a stainless steel reducer is welded to the other end of the stainless steel main pipe by a welding furnace.

[0013] As a further optimization of the above technical solution, the inner diameter of the outer part of the stainless steel reducer is smaller than the inner diameter of the welding point between the stainless steel reducer and the other end of the stainless steel main pipe.

[0014] As a further optimization of the above technical solution, the welding connection is one of the following welding connections: furnace welding connection, argon arc welding connection, high frequency welding connection, flame welding connection, and electric welding connection.

[0015] The outstanding advantages of the utility model compared with the prior art are:

[0016] 1. The utility model can directly weld the stainless steel main pipe and the stainless steel joint in a welding furnace after they are butt-jointed, thereby eliminating the disadvantages of using a brass joint and its copper bushing, which results in many accessories and high production costs.

[0017] 2. The utility model arranges a wire drawing groove on the joint surface to be welded on the stainless steel joint, and utilizes the siphon principle to prevent the solder from entering the welded stainless steel pipe, thereby avoiding the pollution and / or blockage caused by the solder entering the welded stainless steel pipe.

[0018] 3. The utility model arranges a wire drawing groove on the welding joint surface and utilizes the siphon principle to adsorb the solder near the welding surface, so that the welding surface is large, uniform and sealed.

[0019] 4. The utility model has a simple structure, is easy to manufacture, has a low production cost, and is suitable for welding stainless steel pipes and stainless steel joints of different diameters in a welding furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0021] Figure 2 It is a cross-sectional view of the stainless steel joint of the utility model.

[0022] Figure 3 It is a structural sectional view of a stainless steel main pipe and a stainless steel joint of the utility model.

[0023] Figure 4 yes Figure 1 A partial enlarged view of part A in the middle. DETAILED DESCRIPTION

[0024] The present invention will be further described below with reference to the accompanying drawings. Figure 1-Figure 4 :

[0025] A metal pipe connection structure comprises a stainless steel main pipe 10 and a metal branch pipe 30 welded to the stainless steel main pipe 10, one end of a stainless steel joint 20 is expanded to form a first expanded diameter portion 21, an inner diameter D2 of the first expanded diameter portion 21 is equal to the outer diameter of the stainless steel main pipe 10, an inner diameter D1 of a middle portion 23 of the stainless steel joint is equal to the inner diameter D3 of the stainless steel main pipe 10, an inner surface of the first expanded diameter portion 21 is provided with circumferentially spaced and axially extending first drawing grooves 22 made by a metal drawing process, an end of the stainless steel main pipe 10 is inserted into the first expanded diameter portion of the stainless steel joint 20 and solder or solder paste is added to be welded and connected, and the stainless steel main pipe 10 and the first expanded diameter portion of the stainless steel joint 20 are welded to form a welding connection layer 40.

[0026] As a further optimization of the above technical solution, the middle portion of the stainless steel joint 20 has the same inner diameter as that of the stainless steel main pipe 10 .

[0027] As a further optimization of the above technical solution, the depth of the first wire drawing groove 22 gradually increases from the middle of the inner wall of the first diameter expansion portion 21 to the outside.

[0028] As a further optimization of the above technical solution, a second expansion neck 24 is provided at the other end of the stainless steel main pipe 10 .

[0029] As a further optimization of the above technical solution, an internal thread is provided on the inner wall of the second expansion neck portion 24 .

[0030] As a further optimization of the above technical solution, a second wire drawing groove 25 which is circumferentially spaced and axially extending and is made by a metal wire drawing process is provided in the middle of the inner wall of the second expansion neck portion 24 .

[0031] As a further optimization of the above technical solution, the depth of the second wire drawing groove 25 gradually increases from the inner side of the middle part of the inner wall of the second expansion neck 24 to the outside.

[0032] As a further optimization of the above technical solution, the inner diameter of the second expanded neck 24 is equal to or smaller than the outer diameter of the stainless steel main pipe 10 .

[0033] As a further optimization of the above technical solution, the inner diameter of the second expanded neck 24 is greater than the outer diameter of the stainless steel main pipe 10 .

[0034] As a further optimization of the above technical solution, the welding connection is one of the following welding connections: furnace welding connection, argon arc welding connection, high frequency welding connection, flame welding connection, and electric welding connection.

[0035] As a further optimization of the above technical solution, a necking joint 50 is sleeved on the other end of the stainless steel main pipe 10 , and the inner diameter D4 of the output end of the necking joint 50 is smaller than the inner diameter D5 of the stainless steel main pipe 10 .

[0036] The utility model utilizes the stainless steel wire drawing process of the prior art to process a circle of axial first and second wire drawing grooves on the stainless steel surface. This is a further limitation of the first and second wire drawing grooves or a detailed expression of the shapes of the first and second wire drawing grooves, and is not an invention of the stainless steel wire drawing process.

[0037] The furnace welding refers to a high temperature furnace that can heat the stainless steel main pipe 10 and the stainless steel joint 20 at high temperature and melt the solder to form a welding connection with the stainless steel main pipe 10 and the stainless steel joint 20 respectively.

[0038] The metal branch pipe is made of stainless steel or copper.

[0039] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions or technical features described in the aforementioned embodiments can still be simply replaced or modified with similar technologies, and these simple replacements or modifications do not deviate the essence of the corresponding technical solutions from the spirit and substance of the technical solutions of the embodiments of the present invention, and are still within the protection scope of the present invention.

Claims

1. A metal pipe connection structure, comprising a stainless steel main pipe and a metal branch pipe welded to the stainless steel main pipe, characterized in that: One end of the stainless steel joint is expanded to form a first expanded diameter portion, the inner surface of the first expanded diameter portion is provided with first drawing grooves which are circumferentially spaced and axially extended and made by a metal drawing process, the end of the stainless steel main pipe is inserted into the expanded diameter portion of the stainless steel joint, and the end of the stainless steel main pipe is inserted into the expanded diameter portion of the stainless steel joint and connected by welding with solder or solder paste.

2. A metal pipe connection structure according to claim 1, characterized in that: The middle portion of the stainless steel joint has the same inner diameter as that of the stainless steel main pipe.

3. A metal pipe connection structure according to claim 1, characterized in that: The depth of the first wire drawing groove gradually increases from the middle of the inner wall of the first diameter expansion portion toward the outside.

4. A metal pipe connection structure according to claim 1, characterized in that: The other end of the stainless steel main pipe is provided with a second expansion neck.

5. A metal pipe connection structure according to claim 4, characterized in that: An internal thread is arranged on the inner wall of the second expansion neck portion.

6. A metal pipe connection structure according to claim 4, characterized in that: The middle part of the inner wall of the second expansion neck portion is provided with second drawing grooves which are circumferentially spaced and axially extended and are made by metal drawing process.

7. A metal pipe connection structure according to claim 6, characterized in that: The depth of the second wire drawing groove gradually increases from the inner side of the middle part of the inner wall of the second expansion neck portion to the outside.

8. The metal pipe connection structure according to claim 4, characterized in that: The inner diameter of the second expanded neck portion is equal to or smaller than the outer diameter of the stainless steel main pipe.

9. A metal pipe connection structure according to claim 8, characterized in that: The inner diameter of the second expanded neck portion is greater than the outer diameter of the stainless steel main pipe.

10. The metal pipe connection structure according to claim 1, characterized in that: The welding connection is one of the following welding connections: furnace welding connection, argon arc welding connection, high frequency welding connection, flame welding connection, and electric welding connection.

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