Manufacturing method of integrated pipe fittings

Abstract

This invention relates to the field of metal pipe fittings technology, and in particular to a method for manufacturing an integrated pipe fitting, comprising the following steps: calculating and cutting a pipe blank according to the finished pipe fitting dimensions; hot-melting the first end of the pipe fitting to form a coaxial ball head, and using the residual heat of processing to extrude it with a die to obtain an integrated first joint body, which is then machined to meet dimensional and tolerance requirements; after fitting an integral flange onto the second end of the pipe fitting, repeating the hot-melting, extrusion, and machining processes to produce a second joint body, so that the integral flange is axially confined between the two joint bodies; grinding and cleaning the pipe fitting, then bending it into shape, and finally inspecting and packaging it to obtain the finished pipe fitting. This invention achieves seamless integrated molding of the joint and pipe fitting, eliminating welding defects, significantly improving the sealing performance and fatigue life of the pipe fitting, and providing a reasonable process and stable finished product quality.

Description

Technical Field

[0001] This invention relates to the field of metal pipe fittings technology, and in particular to a method for manufacturing an integrated joint pipe fitting. Background Technology

[0002] In locomotive and rolling stock braking lines and other hydraulic and pneumatic transmission systems, metal pipe fittings often use flange connections. Current technology generally fixes the flange to the pipe body by welding. Welded connections are susceptible to defects such as slag, shrinkage cavities, lack of fusion, and cracks due to factors like welding process and operator skill. They also pose a risk of leakage under long-term vibration and pressure fluctuation conditions, and have a relatively low fatigue life. Summary of the Invention

[0003] The present invention aims to solve the above-mentioned defects and provide a method for manufacturing an integrated connector pipe fitting.

[0004] To overcome the deficiencies in the prior art, the technical solution adopted by the present invention to solve its technical problem is: a method for manufacturing an integrated pipe fitting, comprising the following steps:

[0005] S1. Calculate the cutting length based on the final formed dimensions of the pipe fitting and cut the material accordingly;

[0006] S2. The first end of the pipe fitting is hot-melted and formed by heating the end of the pipe fitting to a temperature range in which the material grain size does not change and the strength decreases to a temperature range in which it can be extruded and formed, so that the material at the end of the pipe fitting is partially melted and agglomerated into a ball head, the axis of the ball head coincides with the axis of the pipe fitting;

[0007] S3. In the residual heat state after the hot melt molding in step S2, the ball head is extruded using a mold to form a first joint body that is continuously integrated with the pipe material;

[0008] S4. Machining the first connector body to obtain a first connector body that meets the design dimensions and tolerance requirements;

[0009] S5. Insert the integral flange from the second end of the pipe fitting;

[0010] S6. Repeat steps S2 to S4 on the second end of the pipe fitting to form a second joint body that meets the design requirements, so that the integral flange is axially confined between the first joint body and the second joint body.

[0011] S7. After grinding and cleaning, the pipe fitting is bent into shape to obtain the finished pipe fitting;

[0012] S8. Finished product inspection and packaging for future use.

[0013] In a further improvement, in step S2, the hot melt forming is performed using an electric conductive heating method.

[0014] Further improvements include selecting the hot melt temperature and extrusion residual temperature in steps S2 and S3 to ensure that the chemical composition of the joint body is consistent with the original pipe after processing.

[0015] In a further improvement, the material of the pipe fitting is titanium-stabilized austenitic heat-resistant stainless steel, and the hot-melt temperature in step S2 and the residual temperature maintained in step S3 are in the range of 1050℃~1150℃.

[0016] In a further improvement, in step S3, the cavity of the mold corresponds to the shape of the finished connector body, and the ball material is squeezed to flow and fill in the mold to form a connector body that is integral with the pipe fitting and has the required coaxiality.

[0017] In a further improvement, in step S5, the minimum diameter of the inner bore of the integral flange is smaller than the maximum diameter of the outer contour of the first joint.

[0018] Further improvements are made in step S7, where bending is performed after the first joint body, the second joint body, and the integral flange are installed. The pipe fitting is bent according to the product design shape, and the relative position and angle of the joints at both ends of the pipe fitting meet the assembly requirements.

[0019] The beneficial effects of this invention are: the pipe fittings made in this way have a seamless integral structure between the joint and the pipe body, and the chemical composition, grain size and mechanical properties of the material are almost the same as those of the original pipe material. The fatigue life is more than 60 times that of the welded joint. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Figure 1 This is a schematic diagram of the main sectional view of the pipe fitting in this invention;

[0022] Figure 2 This is a schematic diagram of the main cross-sectional structure of the pipe fitting with a ball head in this invention;

[0023] Figure 3 This is a schematic diagram of the main cross-sectional structure of the pipe fitting with the first connector body in this invention;

[0024] Figure 4 This is a schematic diagram of the main cross-sectional structure of the pipe fitting equipped with an integral flange in this invention.

[0025] Figure 5 This is a schematic diagram of the front cross-sectional structure of the finished product in this invention;

[0026] In the diagram, 1-pipe fitting, 2-ball head, 3-first joint body, 4-second joint body, 5-integral flange. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] A method for manufacturing an integrated pipe fitting includes the following steps:

[0029] S1, see also Figure 1 Based on the design dimensions of the final formed product of pipe fitting 1, calculate the required blank length. The calculation must consider the changes in material length caused by subsequent hot-melt forming, extrusion, and machining processes, and accordingly accurately cut the blank of pipe fitting 1 to complete the blanking process.

[0030] S2, see also Figure 2 The first end of the pipe fitting 1 is hot-melted and formed by heating the end of the pipe fitting 1 to a temperature range in which the material grain size does not change and the strength is reduced to a temperature range in which it can be extruded and formed, so that the material at the end of the pipe fitting 1 is partially melted and agglomerated into a ball head 2, the axis of the ball head 2 being coincident with the axis of the pipe fitting 1;

[0031] S3. In the residual heat state after the hot melt molding in step S2, the ball head 2 is squeezed using a mold with a cavity corresponding to the shape of the finished connector body, so that the material of the ball head 2 flows and fills in the mold cavity to form a first connector body 3 that is continuous and integral with the material of the pipe fitting 1.

[0032] S4, see also Figure 3 The first connector body 3 is machined to remove excess material, so that it finally meets the dimensional accuracy, geometric tolerance and surface roughness requirements specified in the design drawings, thereby obtaining a first connector body 3 that meets the standard.

[0033] S5, see also Figure 4 Insert the integral flange 5 from the second end of the pipe fitting 1;

[0034] S6, see also Figure 5 Repeat steps S2 to S4 on the second end of the pipe fitting 1 to form a second joint body 4 that meets the design requirements, so that the integral flange 5 is axially confined between the first joint body 3 and the second joint body 4.

[0035] S7. After grinding and cleaning the pipe fitting 1, the pipe fitting 1 is bent into shape using a pipe bending machine or CNC pipe bending process so that the relative position and angle of the joints at both ends of the pipe fitting 1 meet the assembly requirements, and the finished pipe fitting 1 is obtained.

[0036] S8. Finished product inspection and packaging for future use; including but not limited to: dimensional inspection (key dimensions of joints, bend angles and spatial positions), visual inspection (no cracks, scratches, or oxidation on the surface), flange mobility inspection, and necessary pressure sealing tests. After passing inspection, the finished products are treated with rust prevention and packaged according to regulations for shipment.

[0037] In step S2, the hot melt forming adopts an conductive heating method. By controlling the current and heating time, the end of the pipe 1 is locally made to reach the hot melt temperature.

[0038] The hot melt temperature and extrusion residual temperature selected in steps S2 and S3 ensure that the chemical composition of the material at the joint after processing is consistent with that of the original pipe fitting 1, the metallographic structure remains unchanged with austenite and grain size, and the mechanical properties are not reduced.

[0039] The material of the pipe fitting 1 is titanium-stabilized austenitic heat-resistant stainless steel, and the hot-melt temperature in step S2 and the preheating temperature maintained in step S3 are in the range of 1050℃~1150℃.

[0040] In step S3, the cavity of the mold corresponds to the shape of the finished connector body. The material of the ball head 2 is squeezed to flow and fill in the mold, forming a connector body that is integral with the pipe fitting 1 and has the required coaxiality.

[0041] In step S5, the minimum diameter of the inner hole of the integral flange 5 is smaller than the maximum diameter of the outer contour of the first connector body, so as to facilitate free sliding but be axially limited after the connector body is formed. The integral flange 5 is fixedly installed by bolts, so that the connector body is connected to the connecting pipeline. The first connector body 3 and the second connector body 4 are stepped structures, and sealing rings can be fitted on them to ensure the sealing performance after connection.

[0042] In step S7, bending and forming are carried out after the first joint body 3, the second joint body 4 and the integral flange 5 are installed. The pipe fitting 1 is bent according to the product design shape, and the relative position and angle of the joints at both ends of the pipe fitting 1 meet the assembly requirements.

[0043] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for manufacturing an integrated pipe fitting, characterized in that, Includes the following steps: S1. Calculate the cutting length and cut the material according to the final forming size of the pipe fitting (1); S2. The first end of the pipe fitting (1) is hot melt formed by heating the end of the pipe fitting (1) to a temperature range in which the material grain size does not change and the strength is reduced to a temperature range in which it can be extruded, so that the material at the end of the pipe fitting (1) is partially melted and aggregated into a ball head (2), and the axis of the ball head (2) coincides with the axis of the pipe fitting (1). S3. In the residual temperature state after the hot melt molding in step S2, the ball head (2) is extruded using a mold to form a first joint body (3) that is integral with the material of the pipe fitting (1). S4. The first connector body (3) is machined to obtain a first connector body (3) that meets the design dimensions and tolerance requirements. S5. Insert the integral flange (5) from the second end of the pipe fitting (1); S6. Repeat steps S2 to S4 on the second end of the pipe fitting (1) to form a second joint body (4) that meets the design requirements, so that the integral flange (5) is axially confined between the first joint body (3) and the second joint body (4). S7. After grinding and cleaning the pipe fitting (1), it is bent into shape to obtain the finished pipe fitting (1); S8. Finished product inspection and packaging for future use.

2. The method for manufacturing an integrated pipe fitting as described in claim 1, characterized in that: In step S2, the hot melt forming is performed using an conductive heating method.

3. The method for manufacturing an integrated pipe fitting as described in claim 1, characterized in that: The hot melt temperature and extrusion residual temperature selected in steps S2 and S3 ensure that the chemical composition of the joint body is consistent with the original pipe fitting (1) after processing.

4. The method for manufacturing an integrated connector pipe fitting as described in claim 1, characterized in that: The material of the pipe fitting (1) is titanium stabilized austenitic heat-resistant stainless steel, and the hot melt temperature in step S2 and the residual temperature maintained in step S3 are in the range of 1050℃~1150℃.

5. The method for manufacturing an integrated connector pipe fitting as described in claim 1, characterized in that: In step S3, the cavity of the mold corresponds to the shape of the finished connector body. The material of the ball head (2) is squeezed to flow and fill in the mold, forming a connector body that is integral with the pipe fitting (1) and has the required coaxiality.

6. The method for manufacturing an integrated connector pipe fitting as described in claim 1, characterized in that: In step S5, the minimum diameter of the inner hole of the integral flange (5) is less than the maximum diameter of the outer contour of the first joint body (3).

7. The method for manufacturing an integrated pipe fitting as described in claim 1, characterized in that: In step S7, bending is performed after the first joint body (3), the second joint body (4) and the integral flange (5) are installed. The pipe fitting (1) is bent according to the product design shape, and the relative position and angle of the joints at both ends of the pipe fitting (1) meet the assembly requirements.

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