Forming method of corrosion-resistant copper alloy tee with equal wall thickness based on embedded punch die

Abstract

The application provides a corrosion-resistant copper alloy tee joint equal-wall thickness forming method based on an embedded punch die, and comprises the following steps: step one, blanking; step two, hydraulic forming: placing a pipe in a hydraulic forming die, and forming a tee joint blank through cooperation of a punch in the hydraulic forming die and hydraulic oil; step three, penetration detection; and step four, machining: machining the tee joint blank to a specified size according to requirements of a drawing to obtain a required tee joint. Through the corrosion-resistant copper alloy tee joint equal-wall thickness forming method based on the embedded punch die, the device for hydraulic forming can be optimized, tee joint equal-wall thickness forming is realized, problems such as increase of the wall thickness of the main pipe and material accumulation are avoided, the surface quality of the prepared tee joint is improved, the length of the blank required for preparation of the tee joint is reduced, and the efficiency of preparation of the tee joint is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal material processing and manufacturing, in particular to a corrosion-resistant copper alloy tee joint equal-wall forming method based on an embedded punch die. BACKGROUND

[0002] Copper alloy has excellent mechanical properties, anti-biofouling performance, and seawater corrosion resistance, and is widely used in pipeline systems, condenser pipes, propellers, pump valves, and other components in the fields of ships, seawater desalination, and offshore drilling platforms. Tee joints are important components in pipeline systems, and are currently mainly formed by internal high-pressure water expansion. The principle of tee joint internal high-pressure water expansion forming is to use a booster to generate high pressure, and the metal blank flows under the high liquid pressure and axial extrusion force, forming a closed internal high-pressure area inside the pipe blank, and the pipe blank flows closely along the outer membrane cavity to form the branch pipe required by the pipe die cavity. Due to the application of axial force to the pipe, the main pipe will thicken during forming, and more raw materials are required, which increases the weight of the tee joint product.

[0003] The existing patent CN212598006U "A tee joint non-accumulation extrusion die" introduces a non-accumulation extrusion die for tee joints, which includes a die body, a tee joint is arranged inside the die body, a metal body for preventing accumulation is placed inside the tee joint, a die pipe is further arranged inside the die body, a thimble is in contact with the left and right end faces of the metal body, the metal body fills the inner cavity of the tee joint, and the die body is divided into two parts, which are combined to form the die body. The key point of this patent is that a metal body for preventing accumulation is placed inside the tee joint, so that the main pipe does not accumulate during forming. However, the preparation of tee joints by this extrusion die is prone to require a long length of material to achieve the preparation of tee joints, which increases the cost of tee joint preparation. Therefore, it is of great significance to study how to optimize the tee joint preparation device, improve the efficiency of tee joint preparation, and reduce the cost of tee joint preparation.

[0004] Patent CN103909133B discloses a composite punch device and forming method for forming multi-port pipe fittings with equal wall thickness. The composite punch device includes a feed punch coaxially assembled with a liquid-filling mandrel, the feed punch being sequentially connected to a guide block and a hydraulic cylinder; the liquid-filling mandrel is provided with several liquid-guiding rings, all of which are connected to the liquid inlet on the guide block; a sealing ring is provided between the feed punch and the liquid-filling mandrel, and the feed punch can move along the axial direction of the liquid-filling mandrel; the forming method includes the following steps: 1) placing the pipe blank into a mold and closing the mold; 2) inserting the left and right composite punch devices from the left and right ends of the pipe blank respectively, and filling the liquid-filling mandrels in the left and right composite punch devices... 3) The tops of the rods contact each other; 4) The left and right ends of the tube blank are sealed, and high-pressure liquid is injected through the liquid-filling mandrel in the left and right composite punch device; 5) The feed punch in the left and right composite punch device is pushed to axially feed material, and the pressure of high-pressure liquid in the tube blank is controlled by the liquid-filling mandrel in the left and right composite punch device; 6) After forming, the left and right composite punch devices are removed to obtain a multi-way pipe fitting with uniform wall thickness after forming, which can effectively reduce the accumulation of material in the middle of the tube blank and improve the uniformity of wall thickness of the multi-way pipe fitting, especially the main pipe; however, the tee prepared by the above method will still have material accumulation inside, which will affect the wall thickness and weight of the tee. Summary of the Invention

[0005] In view of this, the present invention aims to propose a method for forming corrosion-resistant copper alloy tees with equal wall thickness based on an embedded punch die, in order to solve the problem in the existing technology that, due to the axial force applied to the pipe during the tee manufacturing process, the main pipe of the tee will thicken during forming, requiring a large amount of raw materials and increasing the weight of the finished tee. This method aims to achieve equal wall thickness forming of tees by optimizing the hydroforming device, avoiding the problems of increased main pipe wall thickness and material accumulation, improving the surface quality of the prepared tee, reducing the length of material required for tee manufacturing, and improving the efficiency of tee manufacturing.

[0006] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0007] The present invention relates to a method for forming corrosion-resistant copper alloy tees with equal wall thickness based on an embedded punch die, the method comprising the following steps:

[0008] Step 1, Material Cutting: The raw material is cut into pieces, using seamless copper alloy tubing as the raw material;

[0009] Step 2, Hydraulic forming: The pipe is placed in the hydraulic forming mold, and a tee blank is formed by the action of the punch and hydraulic oil in the hydraulic forming mold;

[0010] Step three, penetration detection: first, the three-way blank is cleaned of attachments, and then the three-way blank is subjected to penetration detection to determine whether the prepared three-way blank is qualified. If so, step four is performed.

[0011] Step four, machining: the three-way blank is machined to the specified size according to the requirements of the drawing to obtain the required prepared three-way.

[0012] Further, step one includes:

[0013] Step S11: blanking: selecting a copper alloy seamless pipe as a raw material;

[0014] Step S12: cutting the pipe to the required specified size;

[0015] Step S13: removing the end burr of the cut pipe.

[0016] Further, in step two, the hydraulic forming die includes an upper die, a lower die, a first punch, a second punch, and a core rod. The first through hole is formed between the upper die and the lower die, the pipe is arranged in the first through hole, the first through hole is connected or separated from the first punch and the second punch at both ends, the first punch and the second punch are connected with the power device at the end away from the first through hole, and the core rod is arranged in the first through hole. The one end of the core rod abuts against the inside of the first punch through the elastic device, and the other end of the core rod abuts against or separates from the second punch.

[0017] Further, the upper die includes a first groove, and the lower die includes a second groove. After the upper die and the lower die are connected, the first groove and the second groove are connected to form the first through hole, and the second through hole is arranged through the second groove and communicates with the first through hole.

[0018] Further, the first punch includes a first punch groove and a second punch groove, both of which are arranged on the inside of the first punch. The first punch groove is arranged at the end of the first punch away from the first through hole, the elastic device is arranged inside the first punch groove, and the end of the core rod facing the elastic device is arranged in the first punch groove and the second punch groove in a movable manner.

[0019] Further, the core rod includes a core one rod and a core two rod. The one end of the core two rod abuts against the elastic device through the core one rod, and the other end of the core two rod is connected or separated from the second punch. The core one rod is arranged in the first punch groove and the second punch groove in a movable manner, and the core two rod is arranged in the second punch groove in a movable manner.

[0020] Further, the outer diameter of the core one rod is less than the outer diameter of the core two rod.

[0021] Further, the second punch includes a third through hole and a fourth through hole. The third through hole is arranged inside the second punch, and the fourth through hole communicates with the third through hole at one end and is arranged through the second punch at the other end.

[0022] Further, step two comprises:

[0023] Step S21: placing the pipe in the lower mold, and closing the upper mold and the lower mold;

[0024] Step S22: starting the power device, and respectively controlling the first punch and the second punch to move towards each other, under the action of the power device, the core rod abuts against the second punch;

[0025] Step S23: the power device pushes the first punch and the second punch at a set pushing speed, and controls the hydraulic device to inject hydraulic oil into one end of the third through hole in the second punch; the hydraulic oil exerts pressure on the inner wall of the pipe on the side of the lower mold through the third through hole, so that the side wall of the pipe at the position corresponding to the second through hole is deformed, the hydraulic oil fills into the deformed position, and a tee branch pipe is formed;

[0026] Step S24: judging whether the first punch and the second punch both reach a set pushing distance, if yes, executing step S25; if no, returning to step S23;

[0027] Step S25: the tee blank is prepared, the power device is turned off, and the first punch, the second punch and the core rod all return to the original positions under the action of the pressure, and the first punch, the second punch and the core rod are all separated from the tee blank.

[0028] Further, step three comprises:

[0029] Step S31: penetration detection: cleaning the tee blank;

[0030] Step S32: penetration detection of the tee blank: spraying cleaning agent to thoroughly clean the tee blank; after cleaning, spraying penetrant on the surface of the tee blank, and setting a penetration time of ≥t1 min; after penetration, removing the penetrant on the surface of the tee blank and cleaning with the cleaning agent;

[0031] Step S33: judging whether the surface of the tee blank is dry, if no, repeating step S33; if yes, spraying developing agent and observing the display change, and executing step S34;

[0032] Step S34: after a developing time of ≥t2 min, judging whether the prepared tee blank is qualified, if yes, meeting the acceptance conditions, the tee blank is qualified, and executing step four; if no, not meeting the acceptance conditions, the tee blank is unqualified.

[0033] Compared with the prior art, the corrosion-resistant copper alloy tee equal-wall thickness forming method based on the embedded punch mold has the following beneficial effects:

[0034] Through the method, the support to the main pipe of the pipe material can be realized through the double action of the core rod connected with the first punch and the second punch, the thickening and accumulation of the main pipe in the deformation process of the tee joint can be prevented, the tee joint with equal wall thickness can be formed, the problems of the increase of the wall thickness of the main pipe and the material accumulation can be avoided, the surface quality of the prepared tee joint can be improved, the length of the blank required for the preparation of the tee joint can be reduced, and the efficiency of the preparation of the tee joint can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0035] The accompanying drawings, which form a part of the present application, are intended to provide further understanding of the present application, and are used in the interpretation of the application together with its description. The illustrative embodiments of the present application and their description serve to explain the application. In the drawings:

[0036] Figure 1 It is an overall schematic diagram of the tee joint mold for equal wall thickness forming;

[0037] Figure 2 It is a schematic diagram of the preparation process of the tee joint blank for equal wall thickness forming;

[0038] Figure 3 It is a schematic diagram of the structure of the seamless pipe material;

[0039] Figure 4 It is a schematic diagram of the structure of the tee joint blank for equal wall thickness t;

[0040] Figure 5 It is a schematic diagram of the main pipe thickening T tee joint blank (T>t) produced by the existing process.

[0041] Explanation of reference signs: 1, upper mold; 2, lower mold; 3, first punch; 31, first punch groove; 32, second punch groove; 4, second punch; 5, core rod; 6, elastic device. DETAILED DESCRIPTION

[0042] The inventive concepts of the present disclosure will be described below using terms that are commonly used by those skilled in the art to convey the substance of their work to others skilled in the art. However, these inventive concepts can be embodied in many different forms, and therefore should not be considered limited to the embodiments described herein.

[0043] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0044] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0045] In order to solve the problems of the existing technology, such as the thickness of the main pipe increasing during the forming of the tee, the amount of raw materials required being more, and the weight of the tee product increasing, due to the axial force applied to the pipe material, the embodiment provides a corrosion-resistant copper alloy tee equal-wall thickness forming method based on an embedded punch die, which comprises the following steps:

[0046] Step one, cutting: cutting the raw material, the raw material being a copper alloy seamless pipe material;

[0047] Step two, hydraulic forming: placing the pipe material in the hydraulic forming die, and forming a tee blank through the cooperation of the punch and hydraulic oil in the hydraulic forming die;

[0048] Step three, penetration detection: first cleaning the tee blank, and then performing penetration detection on the tee blank to determine whether the prepared tee blank is qualified, and if so, performing step four;

[0049] Step four, machining: machining the tee blank to the specified size according to the drawing requirements to obtain the required prepared tee.

[0050] Through the method, the device of hydraulic forming can be optimized, the tee equal-wall thickness forming can be realized, the problems of the main pipe wall thickness increasing and material accumulation can be avoided, the surface quality of the prepared tee can be improved, the length of the cutting required for the preparation of the tee can be reduced, and the efficiency of the preparation of the tee can be improved.

[0051] Step one comprises:

[0052] Step S11: cutting: selecting a copper alloy seamless pipe material as the raw material;

[0053] Step S12: cutting the pipe material to the required specified size;

[0054] Step S13: removing the end burrs of the cut pipe material.

[0055] In step two, the hydraulic forming die comprises an upper die 1, a lower die 2, a first punch 3, a second punch 4, and a core rod 5, a first through hole is formed between the upper die 1 and the lower die 2, the pipe material is arranged in the first through hole, the first through hole is connected or separated from the first punch 3 and the second punch 4 at both ends respectively, the ends of the first punch 3 and the second punch 4 away from the first through hole are connected with a power device respectively, for realizing the relative or opposite movement of the first punch 3 and the second punch 4 in the first through hole under the action of the power device, the core rod 5 is arranged in the first through hole, one end of the core rod 5 abuts against the inside of the first punch 3 through an elastic device 6, and the other end of the core rod 5 abuts against or separates from the second punch 4.

[0056] Further, the upper die 1 comprises a first recess, the lower die 2 comprises a second recess and a second through hole, after the upper die 1 and the lower die 2 are connected, the first recess and the second recess are connected to form a first through hole; the second through hole is arranged through the second recess, the second through hole is communicated with the first through hole, for facilitating the forming of the tee. The first punch 3 comprises a first punch groove 31 and a second punch groove 32, the first punch groove 31 and the second punch groove 32 are both arranged inside the first punch 3, the first punch groove 31 is arranged at one end of the first punch 3 away from the first through hole, the diameter of the first punch groove 31 is smaller than that of the second punch groove, a limiting first step is formed at the connection between the first punch groove 31 and the second punch groove 32, for facilitating the movement of the core rod 5. The elastic device 6 is arranged inside the first punch groove 31, for facilitating the movement of the core rod 5 under the action of the elastic device 6. One end of the core rod 5 towards the elastic device 6 is movably arranged inside the first punch groove 31 and the second punch groove 32, the core rod 5 comprises a core first rod and a core second rod, one end of the core second rod abuts against the elastic device 6 through the core first rod, the other end of the core second rod is connected or separated from the second punch 4, the core first rod is movably arranged inside the first punch groove 31 and the second punch groove 32, and the core second rod is movably arranged inside the second punch groove 32. The core first rod and the core second rod are integrally formed, the outer diameter of the core first rod is smaller than that of the core second rod, a limiting second step is formed at the connection between the core first rod and the core second rod, the limiting second step is attached to or separated from the limiting first step, for facilitating the forming of the tee and timely demolding after the forming. The second punch 4 comprises a third through hole and a fourth through hole, the third through hole is arranged inside the second punch 4, one end of the fourth through hole is communicated with the third through hole, and the other end of the fourth through hole is arranged through the second punch 4, for facilitating the input of hydraulic oil from inside the second punch 4 to the second through hole for preparing the tee, and further applying pressure for the preparation of the tee. The first punch 3 and the second punch 4 are respectively connected with the power device at one end away from the first through hole; in this embodiment, the outer diameter of one end of the core rod 5 away from the elastic device 6 is equal to the outer diameter of one end of the second punch 4 towards the core rod 5, which is smaller than the inner diameter of the pipe, for facilitating the attachment of the outer side wall of the core rod 5 and the second punch 4 to the inner side wall of the pipe. The outer diameter of one end of the second punch 4 towards the core rod 5 is smaller than that of one end of the second punch 4 away from the core rod 5, for facilitating the limiting and preventing the overflow of hydraulic oil. The elastic device 6 can adopt a spring, but is not limited thereto.

[0057] Through the setting of the hydraulic forming die in step two, the die can be simplified, the preparation cost of the tee joint can be reduced, and the efficiency of the preparation of the tee joint can be greatly improved; and through the setting of the second through hole, space is provided for the forming of the tee joint blank; through the setting of the third through hole and the fourth through hole, flow channels are provided for the forming of the tee joint blank under the pressure of the hydraulic oil; through the setting of the core rod 5 and the second punch 4, the change of the wall thickness of the main pipe of the tee joint blank in the forming process is limited, the support of the main pipe of the pipe material is realized, the phenomenon that the wall thickness of the main pipe of the tee joint is easily accumulated or thickened in the pressure forming process is effectively prevented, the preparation of the tee joint blank with equal wall thickness is realized, and the reliability and safety of the preparation of the tee joint are improved.

[0058] Step two comprises:

[0059] Step S21: placing the pipe material in the second groove of the lower die 2, and closing the upper die 1 and the lower die 2;

[0060] Step S22: starting the power device, and controlling the first punch 3 and the second punch 4 to move towards each other; under the action of the power device, the core rod 5 abuts against the second punch 4, and the inside of the pipe material is completely filled, so that the main pipe of the tee joint blank will not be thickened or accumulated when the tee joint blank is formed;

[0061] Step S23: the power device pushes the first punch 3 and the second punch 4 at a set pushing speed, and the hydraulic device injects hydraulic oil into the second punch 4 through the third through hole; the hydraulic oil exerts pressure on the inner wall of the pipe material on the side of the lower die 2 through the third through hole, so that the side wall of the pipe material at the position corresponding to the second through hole is deformed, the hydraulic oil is filled into the deformed position, and the tee joint branch pipe is formed;

[0062] Step S24: when the core rod 5 in the first punch 3 and the outer side wall of the second punch 4 are respectively embedded in the inner side walls of the two ends of the pipe material, it is judged whether the first punch 3 and the second punch 4 have reached the set pushing distance; if yes, step S25 is executed; if no, step S23 is returned;

[0063] Step S25: the preparation of the tee joint blank is completed, the power device is turned off, and the first punch 3, the second punch 4 and the core rod 5 all return to the original position under the action of the pressure, and the first punch 3, the second punch 4 and the core rod 5 are all separated from the tee joint blank.

[0064] Through the double action of the power device and the hydraulic device, the first punch 3 can be separated from or abutted against the second punch 4 through the core rod 5, thereby realizing the supporting effect of the first punch on the main pipe of the tee blank arranged in the first through hole, and the hydraulic oil can be injected into the second through hole through the third through hole and the fourth through hole in the second punch 4, thereby realizing the forming preparation of the branch pipe of the tee blank arranged in the second through hole, thereby realizing the efficient preparation of the tee blank with equal wall thickness, and the problems of thickening or accumulation of the main pipe during the preparation of the tee blank can be avoided. In addition, the equipment forms the tee according to the set advancing speed and pressure, and when the first punch 3 and the second punch 4 reach the set advancing distance, the tee forming is completed, the first punch 3 and the second punch 4 return to the original position, and the first punch 3 and the movable core rod 5 are limited by the limiting device, so that the core rod 5 can be withdrawn at the same time when the first punch 3 exits the mold, thereby saving the demolding process, further simplifying the tee preparation process, and improving the reliability and convenience of the tee preparation.

[0065] Step three comprises:

[0066] Step S31: Penetrant detection: cleaning the adherend of the tee blank;

[0067] Step S32: Penetrant detection of the tee blank: thoroughly cleaning the tee blank by spraying the cleaning agent; after cleaning, spraying the penetrant on the surface of the tee blank, and setting the penetration time to be greater than or equal to t1 min; after penetration, removing the penetrant on the surface of the tee, and cleaning with the cleaning agent;

[0068] Step S33: judging whether the surface of the tee blank is dry, no, repeating step S33; yes, spraying the developer and observing the display change, and executing step S34;

[0069] Step S34: after the developing time is greater than or equal to t2 min, judging whether the prepared tee blank is qualified, yes, meeting the acceptance condition, the tee blank is qualified, and executing step four; no, not meeting the acceptance condition, the tee blank is unqualified;

[0070] Wherein, t1 and t2 are positive numbers, and the specific values of t1 and t2 are set according to the requirements. The way to judge whether the developed tee blank is qualified is to evaluate the developing result according to NB / T 47013.5 'Nondestructive Testing of Pressure Equipment Part 5 Penetrant Testing', and the acceptance is qualified when meeting the I level requirement. In this embodiment, t1 is 10, and t2 is 10.

[0071] Through the penetrant detection of the tee blank, the unqualified tee blank can be removed, the process of measuring after processing is avoided, the quality of the tee is improved, the detection cost is reduced, the detection efficiency is improved, and the precision of the detection is enhanced.

[0072] Example 1:

[0073] The application has been applied to the manufacture of copper alloy DN25-Φ30x2.5 equal-diameter tee joints, and specifically as follows:

[0074] Step one, select Φ30x2.5 copper alloy seamless pipe, adopt full-automatic laser cutting to cut pipe, and the length of the cut pipe is 140±2mm, and the burrs at the end of the cut pipe are removed;

[0075] Step two, hydraulic forming: place the pipe in the middle of the lower die 2, after the upper die 1 and the lower die 2 are closed, the first punch 3 and the second punch 4 are simultaneously pushed to the middle, and hydraulic oil is injected from the channel in the middle of the second punch 4 to apply pressure to the inside. The outer diameter of the end of the movable core rod 5 away from the elastic device 6 and the outer diameter of the end of the second punch 4 towards the core rod 5 are both Φ25-0.2-0.4, the inner diameter of the seamless pipe is Φ30x2.5, and the outer diameter of the end of the movable core rod 5 away from the elastic device 6 and the outer diameter of the end of the second punch 4 towards the core rod 5 are both smaller than the inner diameter of the seamless pipe, so that the core rod 5 and the second punch 4 can be inserted into the inside of the pipe. The movable core rod 5 is in contact with the second punch 4 and is completely filled in the inside of the pipe, and the main pipe will not thicken or accumulate when the tee joint blank is formed. The equipment forms the tee joint blank at a pushing speed of 0.3-0.5mm / S and a pressure of 60-70MPa, and the forming of the tee joint blank is completed when the first punch 3 and the second punch 4 reach the set pushing distance, and then the first punch 3 and the second punch 4 return to the original position. The first punch 3 and the movable core rod 5 are limited by the limiting device, and the core rod 5 will exit the die with the first punch 3. The total length of the main pipe of the tee joint blank is about 95mm, and the total height is about 70mm.

[0076] Step three, penetration detection: the surface of the tee joint blank is cleaned of attachments, and then a cleaning agent is sprayed to further clean thoroughly; after cleaning, a penetrant is sprayed on the surface of the tee joint blank, and the penetration time is not less than 10min; after penetration, the penetrant on the surface of the tee joint blank is removed and cleaned with a cleaning agent; after the surface of the tee joint blank workpiece is dried, a developer is sprayed, and the display change is observed during the developing process, and the developing time is not less than 10min; the developing result is evaluated according to NB / T 47013.5 “Nondestructive Testing of Pressure Equipment Part 5 Penetration Testing”, and the tee joint blank can be accepted if the evaluation meets the requirements of Grade I.

[0077] Step four, machining: the tee joint blank is machined to the specified size according to the drawing requirements.

[0078] Example 2:

[0079] The application has been applied to the manufacture of copper alloy DN200-Φ219.1x4.5 equal-diameter tee joints, and specifically as follows:

[0080] Step one, select Φ219.1x4.5 copper alloy seamless pipe, adopt full-automatic laser cutting pipe, the length of blanking is 470±2mm, remove the end burr after cutting;

[0081] Step two, hydraulic forming: put the pipe in the middle of the lower die 2, after the upper die 1 and the lower die 2 are closed, the first punch 3 and the second punch 4 are pushed to the middle at the same time, and the hydraulic oil is injected from the channel in the middle of the second punch 4 to apply pressure to the inside. The outer diameter of the end of the movable core rod 5 away from the elastic device 6 and the outer diameter of the end of the second punch 4 towards the core rod 5 are both Φ210-0.5-0.8, the inner diameter of the seamless pipe is Φ219.1x4.5, and the outer diameter of the end of the movable core rod 5 away from the elastic device 6 and the outer diameter of the end of the second punch 4 towards the core rod 5 are both smaller than the inner diameter of the seamless pipe, so that the core rod 5 and the second punch 4 can be inserted into the inside of the pipe. The movable core rod 5 will be in contact with the second punch 4 and completely filled in the pipe, and when the tee blank is formed, the main pipe will not be thickened or accumulated. The device forms the tee blank at a pushing speed of 0.5-0.8mm / S and a pressure of 25-30MPa, and when the first punch 3 and the second punch 4 reach the set pushing distance, the tee blank forming is completed, the first punch 3 and the second punch 4 return to the original position, the first punch 3 and the movable core rod 5 are limited by the limiting device, and the core rod 5 will exit the die with the first punch 3. The total length of the tee blank main pipe is about 380mm, and the total height is about 300mm.

[0082] Step three, penetration detection: the formed tee blank should be subjected to penetration detection, and the result should meet the requirements of NB / T 47013.5 "Nondestructive Testing of Pressure Equipment Part 5 Penetration Detection" Class I.

[0083] Step four, machining: the tee blank is machined to the specified size according to the drawing requirements.

[0084] Example 3:

[0085] The application has been applied to the manufacture of copper alloy DN600-Φ610x13 equal-diameter tee, and the specific steps are as follows:

[0086] Step one, select Φ610x13 copper alloy seamless pipe, adopt sawing machine to cut the pipe, the length of blanking is 1080±2mm, remove the end burr after cutting;

[0087] Step two, hydraulic forming: place the pipe in the middle of the lower die 2, after the upper die 1 and the lower die 2 are closed, the first punch 3 and the second punch 4 are pushed to the middle at the same time, and hydraulic oil is injected from the channel in the middle of the second punch 4 to apply pressure to the inside. The outer diameter of the end of the movable core rod 5 away from the elastic device 6 and the outer diameter of the end of the second punch 4 towards the core rod 5 are both Φ584-1-2, the inner diameter of the seamless pipe is Φ610x13, and the outer diameter of the end of the movable core rod 5 away from the elastic device 6 and the outer diameter of the end of the second punch 4 towards the core rod 5 are both smaller than the inner diameter of the seamless pipe, so that the core rod 5 and the second punch 4 can be inserted into the inside of the pipe. The movable core rod 5 will be in contact with the second punch 4 and completely filled in the pipe, and the main pipe will not thicken or produce accumulation when forming the tee blank. The equipment forms the tee blank at a pushing speed of 0.8-1.0 mm / S and a pressure of 18-22 MPa, and the forming of the tee blank is completed when the first punch 3 and the second punch 4 reach the set pushing distance, and then the first punch 3 and the second punch 4 return to the original position. The first punch 3 and the movable core rod 5 are limited by the limiting device, and the core rod 5 will exit the die with the first punch 3. The total length of the main pipe of the tee blank is about 910 mm, and the total height is about 780 mm.

[0088] Step three, penetration detection: clean the surface of the tee blank, then spray cleaning agent for further thorough cleaning; after cleaning, spray penetrant on the surface of the tee blank, and the penetration time is not less than 10 min; after penetration, remove the penetrant on the surface of the tee blank and clean it with cleaning agent; after the surface of the tee blank workpiece is dry, spray developer, and pay attention to observe the display change during the development process, and the development time is not less than 10 min; the development result is evaluated according to NB / T 47013.5 “Nondestructive Testing of Pressure Equipment Part 5 Penetrant Testing”, and the tee blank can be accepted if it meets the requirements of grade I.

[0089] Step four, machining: the tee blank is machined to the specified size according to the drawing requirements.

[0090] Through the setting of the hydraulic forming device containing the embedded punch, the copper alloy tee with equal wall thickness can be successfully formed through the processes of blanking, hydraulic forming, penetration detection, machining and the like. Through the application of embodiments 1-3, it can be concluded that the blanking length in the present application is reduced by about 30% compared with the process used in the prior art (CN212598006U), and the surface quality is good, which is suitable for batch production of corrosion-resistant copper alloy tees.

[0091] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for forming a tee fitting of a corrosion-resistant copper alloy with equal wall thickness based on an embedded punch die, characterized by, The method comprises the following steps: Step one, blanking: cutting and blanking the raw material, the raw material adopts copper alloy seamless pipe as the raw material; Step two, hydraulic forming: placing the pipe in the hydraulic forming die, and forming the tee blank through the cooperation of the punch in the hydraulic forming die and the hydraulic oil; In step two, the hydraulic forming die comprises an upper die (1), a lower die (2), a first punch (3), a second punch (4) and a core rod (5), a first through hole is formed between the upper die (1) and the lower die (2), the pipe is arranged in the first through hole, the first through hole is connected or separated from the first punch (3) and the second punch (4) at both ends respectively, the first punch (3) and the second punch (4) are connected with the power device at the ends away from the first through hole respectively, and the core rod (5) is arranged in the first through hole, one end of the core rod (5) abuts against the inner side of the first punch (3) through the elastic device (6), and the other end of the core rod (5) abuts against or separates from the second punch (4); Step two comprises: Step S21: placing the pipe in the lower die (2), and closing the upper die (1) and the lower die (2); Step S22: starting the power device, and controlling the first punch (3) and the second punch (4) to move towards each other, under the action of the power device, the core rod (5) abuts against the second punch (4); Step S23: the power device advances the first punch (3) and the second punch (4) at a set advancing speed, and controls the hydraulic device to inject hydraulic oil into one end of the third through hole in the second punch (4); the hydraulic oil applies pressure to the inner wall of the pipe on the side of the lower die (2) through the third through hole, so that the side wall of the pipe at the position corresponding to the second through hole is deformed, the hydraulic oil is filled into the deformed position, and the tee branch pipe is formed; Step S24: whether the first punch (3) and the second punch (4) reach the set advancing distance is judged, if yes, step S25 is executed; if no, step S23 is returned; Step S25: the tee blank is prepared, the power device is turned off, the first punch (3), the second punch (4) and the core rod (5) return to the original positions under the action of the pressure, and the first punch (3), the second punch (4) and the core rod (5) are separated from the tee blank; Step three, penetration detection: after the tee blank is cleaned of attachments, the tee blank is subjected to penetration detection, and whether the prepared tee blank is qualified is judged, if yes, step four is executed; Step four, machining: the tee blank is machined to a specified size according to the requirements of the drawing, and the required tee is obtained.

2. A method of forming a corrosion resistant copper alloy tee fitting with equal wall thicknesses based on an embedded punch die according to claim 1, characterized in that, The step one comprises: Step S11: blanking: selecting copper alloy seamless pipe as the raw material; Step S12: cutting the pipe according to the required specified size; Step S13: removing the end burrs of the cut pipe.

3. A method of forming a corrosion resistant copper alloy tee fitting with equal wall thicknesses based on an embedded punch die according to claim 2, characterized in that, The upper die (1) comprises a first groove, the lower die (2) comprises a second groove, the first groove and the second groove are connected to form the first through hole after the upper die (1) and the lower die (2) are connected, the second through hole is arranged through the second groove, and the second through hole is in communication with the first through hole.

4. A method of forming a corrosion resistant copper alloy tee fitting with equal wall thicknesses based on an embedded punch die according to claim 3, characterized in that, The first punch (3) comprises a first punch groove (31) and a second punch groove (32), both of which are arranged inside the first punch (3), the first punch groove (31) is arranged at one end of the first punch (3) away from the first through hole, the elastic device (6) is arranged inside the first punch groove (31), and one end of the core rod (5) towards the elastic device (6) is movably arranged inside the first punch groove (31) and the second punch groove (32).

5. A method of forming a corrosion resistant copper alloy tee fitting with equal wall thicknesses based on an embedded punch die according to claim 4, characterized in that, The core rod (5) comprises a core one rod and a core two rod, one end of the core two rod abuts against the elastic device (6) through the core one rod, the other end of the core two rod is connected or separated from the second punch (4), the core one rod is movably arranged inside the first punch groove (31) and the second punch groove (32), and the core two rod is movably arranged inside the second punch groove (32).

6. A method of forming a corrosion resistant copper alloy tee fitting with equal wall thicknesses based on an embedded punch die according to claim 5, characterized in that, The outer diameter of the core one rod is smaller than that of the core two rod.

7. A method of forming a corrosion resistant copper alloy tee fitting with equal wall thicknesses based on an embedded punch die according to claim 2, characterized in that, The second punch (4) comprises a third through hole and a fourth through hole, the third through hole is arranged inside the second punch (4), one end of the fourth through hole communicates with the third through hole, and the other end of the fourth through hole penetrates through the second punch (4).

8. A method of forming a corrosion resistant copper alloy tee fitting with equal wall thicknesses based on an embedded punch die according to claim 2, characterized in that, The step three comprises: Step S31: Penetration detection: cleaning the adherend of the three-way blank; Step S32: Penetration detection of the three-way blank: thoroughly cleaning the three-way blank by spraying the cleaning agent; after cleaning, spraying the penetrant on the surface of the three-way blank, setting the penetration time ≥t1, the unit of t1 being min; after penetration, removing the penetrant on the surface of the three-way blank and cleaning with the cleaning agent; Step S33: judging whether the surface of the three-way blank is dry, no, repeating step S33; yes, spraying the developing agent and observing the display change, executing step S34; Step S34: after the developing time ≥t2, t2 being min, judging whether the prepared three-way blank is qualified, yes, meeting the acceptance condition, the three-way blank is qualified, executing step four; no, not meeting the acceptance condition, the three-way blank is unqualified.

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