A demoulding mandrel and demoulding method for forging a titanium and titanium alloy thick-walled pipe

Abstract

The present invention discloses a demoulding mandrel for forging a titanium and titanium alloy thick-walled tube body. The demoulding mandrel is inserted into the middle hole of a thick-walled tube blank for forming a titanium and titanium alloy thick-walled tube body. After the thick-walled tube blank is formed into a titanium and titanium alloy thick-walled tube body structure, the demoulding mandrel body can reduce the contact friction between the mandrel and the titanium and titanium alloy thick-walled tube body. The demoulding mandrel provided by the present application can reduce the contact friction with the inner wall of the thick-walled tube during the demoulding process after the thick-walled tube is formed, so that the mandrel is easy to be removed, thereby improving the demoulding efficiency after the thick-walled tube is formed. At the same time, under the effect of achieving effective demoulding, it can solve the problem of increased cost and energy consumption caused by the need to saw and scrap the thick-walled tube when it is difficult to remove the mandrel, and at the same time effectively protect the quality of the mandrel and reduce the production cost of the enterprise.

Description

Technical Field

[0001] The invention relates to the technical field of titanium and titanium alloy thick-walled tube preparation, in particular to a demoulding mandrel and a demoulding method for forging a titanium and titanium alloy thick-walled tube body. Background Art

[0002] Titanium and titanium alloy pipes are mainly pipes made of titanium and titanium alloy metal materials. Since titanium has excellent corrosion resistance and mechanical properties compared to other metal materials, pipes made of titanium materials are widely used in fluid transportation and pipeline systems in the chemical, petroleum, pharmaceutical, aerospace and other fields as well as in other fields.

[0003] There are many methods for forming metal tubes, among which commonly used methods include stretching, forging, rolling and welding. Among them, stretching stretches the metal tube to deform it and form it into the desired shape and size, and is usually used to stretch thick-walled tube blanks. During forging, the metal tube is deformed and formed into the desired shape and size by heating and forging. Rolling rolls the metal tube to deform it and form it into the desired shape and size. Welding forms the desired metal tube by welding multiple metal tube sections together. In the preparation of titanium and titanium alloy tubes, since the sponge titanium raw material becomes a titanium ingot structure after smelting, the subsequent processes mostly involve forging processes, so the corresponding titanium tubes are also mostly formed by forging.

[0004] The current forming process of titanium and titanium alloy thick wall tubes is as shown in the attached manual. Figure 1-5 As shown in the figure, the forged bar is subjected to an oblique rolling and piercing process to form a hole in the center of the bar, that is, a thick-walled tube blank is formed; then a mandrel matching the inner diameter of the hole is inserted into the thick-walled tube blank, and a radial forging machine is used to apply a forging force to the outer wall of the thick-walled tube. Under the support of the mandrel on its inner hole, the thickness of the thick-walled tube blank gradually decreases ( Figure 3-4 As shown), titanium and titanium alloy thick-walled tubes with reduced thickness are formed (usually tubes with a wall thickness greater than 4mm are called thick-walled tubes). However, after the thick-walled tube is formed, due to the application of forging force, the thick-walled tube gradually "coats" on the outer wall of the core rod, and there is a large close contact force between each other, and the axial length of the tube body increases after the tube wall is reduced, resulting in an increase in the contact length (area) between the tube body and the core rod, and thus it is difficult to separate and disassemble the core rod from the thick-walled tube. When disassembling under the action of mechanical external force, overcoming the contact friction and applying a large demoulding external force will cause pulling damage to the tube body and the core rod, making it difficult to separate the core rod from the tube body. In this case, it may usually be necessary to saw the tube body by cutting to remove the core rod (usually the cost of the core rod is high), resulting in the scrapping of the tube body, as well as energy consumption waste in the process of making the tube body, increasing the manufacturing cost of the thick-walled tube. Summary of the invention

[0005] In response to the above-mentioned problems, the present invention aims to provide a demolding mandrel for forging titanium and titanium alloy thick-walled tubes, which makes it easy to demold the mandrel by reducing the contact friction with the inner wall of the thick-walled tube, thereby improving the demolding efficiency of the thick-walled tube after forming, while effectively protecting the quality of the mandrel and reducing the production cost of the enterprise.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is as follows: a demolding mandrel for forging a titanium and titanium alloy thick-walled tube body, characterized in that: the demolding mandrel is inserted into the center hole of a thick-walled tube blank for forming a titanium and titanium alloy thick-walled tube body, and after the thick-walled tube blank is formed into a titanium and titanium alloy thick-walled tube body structure, the demolding mandrel body can reduce the contact friction between it and the titanium and titanium alloy thick-walled tube body.

[0007] Preferably, the demoulding core rod is divided into a spliced ​​structure of multiple segmented bodies.

[0008] Preferably, a splicing rod is commonly provided in the plurality of segment bodies, and when the splicing rod is connected, the end faces of adjacent segment bodies are in contact with each other.

[0009] Preferably, the splicing rod is a screw rod structure threadably connected to each of the segmented bodies.

[0010] Preferably, one end of each segmented body located in the direction of separation from the titanium and titanium alloy thick-walled tube is configured as an arc surface structure, and the other end is configured as an arc groove structure matching the end of the arc surface structure of the adjacent segmented body.

[0011] A demoulding method for a titanium and titanium alloy thick-walled tube forging demoulding mandrel, characterized in that it comprises the following steps:

[0012] S1, splicing all the segmented bodies by a splicing rod and making the side walls of adjacent segmented bodies butt against each other to form a demoulding core rod;

[0013] S2, inserting the demoulding mandrel into the center hole of the thick-walled tube blank;

[0014] S3, under the support of the demoulding mandrel on the inner hole of the thick-walled tube blank, a forging force is applied to the outer wall of the thick-walled tube blank by a radial forging machine to form a titanium or titanium alloy thick-walled tube body;

[0015] S4, disassemble the splicing rod and the demoulding core rod, and connect the splicing rod to the outermost segmented body, drive the segmented body axially out of the inner hole of the titanium and titanium alloy thick-walled tube body, thereby driving multiple segmented bodies out in turn to complete the demoulding operation of the demoulding core rod.

[0016] Preferably, in step S4, the segmented bodies on both sides are respectively removed from both sides based on the center of the demoulding core rod.

[0017] The beneficial effects of the present invention are as follows: during the demolding process after the thick-walled tube is formed, the demolding core rod provided by the present application reduces the contact friction with the inner wall of the thick-walled tube, making the core rod easy to be demolded, thereby improving the demolding efficiency after the thick-walled tube is formed. At the same time, while achieving effective demolding, it can solve the current problem of increased cost and energy consumption caused by the need to saw and scrap the thick-walled tube when it is difficult to demold the core rod, and at the same time effectively protect the quality of the core rod and reduce the production cost of the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a diagram showing the structure of thick-walled tube blank.

[0019] Figure 2 The diagram shows a mandrel being inserted into a thick-walled tube.

[0020] Figure 3 For Figure 2 The outer wall of the thick-walled tube is forged as shown in the figure.

[0021] Figure 4 for Figure 3 Illustration of the fit between the thick-walled tube and the mandrel after forging.

[0022] Figure 5 For the general Figure 4 Illustration of the thick-walled tube product after demoulding the mandrel in Figure 1.

[0023] Figure 6 It is a schematic diagram of the demoulding core rod structure of the present invention.

[0024] Figure 7 The demoulding core rod is disassembled into a plurality of segmented bodies according to the present invention.

[0025] Figure 8 The demoulding mandrel of the present invention is shown in the figure after being used and being separated from the thick-walled tube in sequence.

[0026] Fig. 9 This is a structural diagram of the segmented body of the demoulding core rod of the present invention, with its length gradually increasing from the center to both sides.

[0027] Fig.10 For the present invention Fig. 9 The demoulding core rod and the thick-walled tube are separated in sequence and the separation direction is shown in the figure.

[0028] Fig.11 For the present invention Fig.10 The segmented body will be detached from the diagram soon.

[0029] Fig.12 It is a cross-sectional view of the structure of the abutting ends of adjacent segment bodies of the present invention.

[0030] Fig.13 This is a diagram showing the adjacent segmented bodies of the present invention being spliced ​​together by splicing rods.

[0031] Fig.14 It is a diagram showing the direction of separation and the end surface structure of a single segmented body and a thick-walled tube of the present invention.

[0032] Fig.15 The figure shows a thick-walled tube blank.

[0033] Fig.16 This is a diagram showing the forging of a mandrel through a thick-walled tube blank.

[0034] Fig.17 This is an illustration of a thick-walled tube formed by forging.

[0035] Fig.18 for Fig.17 Illustration of a thick-walled tube after cooling.

[0036] In the figure: 1-thick-walled tube blank; 2-mandrel; 3-thick-walled tube; 4-demolding mandrel; 41-segmented body; 4a-arc surface structure; 4b-arc groove structure; 5-joining rod; 51-pull ring. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0038] Refer to the attached Figures 1 to 14 The demoulding mandrel 4 for forging a titanium and titanium alloy thick-walled tube 3 is shown. The demoulding mandrel 4 is inserted into the center hole of the thick-walled tube 1 blank for forming the titanium and titanium alloy thick-walled tube 3. After the thick-walled tube 1 blank is formed into the titanium and titanium alloy thick-walled tube 3 structure, the demoulding mandrel 4 body can reduce the contact friction between it and the titanium and titanium alloy thick-walled tube 3. At present, after the thick-walled tube 1 is formed into the thick-walled tube 3, the axial length of the tube body increases ( Figure 3-4 As shown), the contact friction between the tube body and the outer wall of the core rod is increased (also including the decrease in the axial linear accuracy of the inner wall of the tube body after the axial length of the tube body increases), making it difficult for the core rod to separate from the tube body. Therefore, the demolding core rod 4 provided in the present application reduces the contact friction with the inner wall of the thick-walled tube 3 during the demolding process after the thick-walled tube 3 is formed, making it easy for the core rod to be removed, thereby improving the demolding efficiency of the thick-walled tube 3 after forming. At the same time, while achieving effective demolding, it can solve the problem of increased cost and energy consumption caused by the need to saw and scrap the thick-walled tube 3 when it is difficult to remove the core rod, and at the same time effectively protect the quality of the core rod and reduce the production cost of the enterprise.

[0039] Specifically, Figure 6-7As shown, the demoulding mandrel 4 is divided into a splicing structure of multiple segmented bodies 41. When the thick-walled tube 3 is forged, the demoulding mandrel 4 is spliced ​​into an integral structure and inserted into the hole in the thick-walled tube 1 blank. After the thick-walled tube 3 is formed, the demoulding mandrel 4 is disassembled into multiple segmented bodies 41, and the multiple segmented bodies 41 after disassembly are a single piece. During the ejection process, each segmented body 41 can greatly reduce the contact friction with the inner wall of the thick-walled tube 3 compared with the overall length of the demoulding mandrel 4, thereby facilitating the smooth ejection of a single segmented body 41. After the multiple segmented bodies 41 are ejected one by one, the entire demoulding mandrel 4 can be quickly ejected, solving the problem that the mandrel is difficult to eject as a whole.

[0040] In order to facilitate the assembly of the demoulding core rod 4 and the subsequent removal of the segmented body 41, Figure 6 As shown, a splicing rod 5 is commonly provided in the plurality of segmented bodies 41, and when the splicing rod 5 is connected, the end faces of the adjacent segmented bodies 41 are in contact with each other. The splicing rod 5 can realize the splicing and assembly of the plurality of segmented bodies 41, and form an integral demoulding mandrel 4, which can be used for the forging operation of the thick-walled tube 1 to form the thick-walled tube 3. After the thick-walled tube 3 is formed, the splicing rod 5 and the plurality of segmented bodies 41 of the demoulding mandrel 4 are disassembled, and then the plurality of segmented bodies 41 are separated from the thick-walled tube 3 from the outside in sequence, so as to realize the sequential demoulding operation.

[0041] Preferably, in order to facilitate the connection and disassembly of the splicing rod 5 and the segment body 41, as Figure 8 , 14 As shown, the splicing rod 5 is a screw structure that is threadedly connected to each of the segmented bodies 41. During assembly, each segmented body 41 is rotated and sleeved on the splicing rod 5 in turn, and the ends of adjacent splicing rods 5 are abutted against each other. In the subsequent demoulding process, after the splicing rod 5 is disassembled from the multiple segmented bodies 41, the splicing rod 5 is threadedly connected to the outermost segmented body 41, and the outer segmented body 41 can be demoulded and disassembled from the thick-walled tube 3 by driving the splicing rod 5 outward (preferably, a pull ring 51 is provided at the outer end of the splicing rod 5), and then all the segmented bodies 41 can be disassembled from the thick-walled tube 3 by threading the splicing rod 5 with each segmented body 41 in turn.

[0042] To further optimize the disassembly method of the segmented body 41, preferably, Figure 10-11 As shown, the segmented bodies 41 can be detached and disassembled from both sides of the tube body, so as to avoid the segmented bodies 41 far from the disassembly end having to completely pass through the entire inner wall of the thick-walled tube 3 during the disassembly process, thereby prolonging the disassembly time and causing long-term contact and wear on the inner wall of the thick-walled tube 3. Therefore, by disassembling from both sides, multiple segmented bodies 41 can be detached more quickly, while reducing the mutual friction and wear between the segmented bodies 41 and the inner wall of the tube body.

[0043] To further optimize the demoulding effect between the segmented body 41 and the thick-walled tube 3, as Figure 9-10 As shown, the length of the segmented body 41 increases in sequence from the center of the demolding mandrel 4 to the two sides. The effect achieved is: since the segmented body 41 located at the center of the thick-walled tube 3 has a longer length of sliding contact with the inner wall of the thick-walled tube 3 than the segmented body 41 on the outside during the disengagement process, it is always in contact with the tube wall during the disengagement process. Therefore, reducing the length of the segmented body 41 located at the center can reduce the contact friction between it and the tube wall during the sliding disengagement process, which is convenient for the smooth disengagement of the segmented body 41 located at the center. At the same time, the shorter segmented body 41 can also reduce the influence of the straightness of the inner wall of the tube body (the segmented body 41 located at the center has a longer stroke during the disengagement process, and is more susceptible to the straightness of the tube wall than the segmented body 41 on the outside). Therefore, under the influence of reducing the friction contact surface and the straightness of the tube body, it is easier to disassemble the segmented body 41 located at the center, and then the demolding effect of the segmented body 41 can be further optimized and improved. Preferably, when demolding, the segmented bodies 41 are sequentially removed from both sides of the tube body as described above.

[0044] In order to further reduce the contact resistance between the segmented body 41 and the tube wall during the demoulding process, Figure 12-13 As shown, one end of each segmented body 41 located in the direction of separation from the titanium and titanium alloy thick-walled tube 3 is provided with a circular arc surface structure 4a, and the other end is provided with an arc groove structure 4b that matches the end of the circular arc surface structure 4a of the adjacent segmented body 41. The specific demoulding process is as follows Fig.14 As shown, in the process of detaching a single segmented body 41, the segmented body 41 is driven to detach in the direction of the arrow, and the arc surface structure 4a arranged at its end can solve the contact friction resistance between the corners of the original straight end face of the segmented body 41 and the tube wall (because the inner wall of the forged thick-walled tube 3 is in close contact with the outer wall of the segmented body 41), thereby facilitating the reduction of the resistance during the detachment of the segmented body 41, facilitating the detachment of the segmented body 41, and also reducing the resistance and friction wear problems caused by the contact between the end face of the segmented body 41 and the tube wall, thereby effectively protecting the surface quality of the tube wall and the segmented body 41.

[0045] The arrangement of the arc surface structures 4 a and the arc groove structures 4 b at both ends of each segment body 41 is arranged according to the demoulding direction of the segment body 41 .

[0046] The present application also provides a demoulding method for forging a titanium and titanium alloy thick-walled tube 3 with a demoulding mandrel 4, comprising the following steps:

[0047] S1, all the segment bodies 41 are spliced ​​together by the splicing rod 5 (preferably, the segment bodies 41 are vaguely spirally sleeved) and the side walls of adjacent segment bodies 41 are abutted against each other to form a demoulding core rod 4, such as Figure 6 Status shown in .

[0048] S2, inserting the demoulding mandrel 4 into the center hole of the thick-walled tube 1 blank.

[0049] S3, under the support of the demoulding mandrel 4 on the inner hole of the thick-walled tube 1 blank, a forging force is applied to the outer wall of the thick-walled tube 1 blank by a radial forging machine to form a titanium or titanium alloy thick-walled tube 3 body, such as Figure 8 Status shown.

[0050] S4, disassemble the splicing rod 5 and the demoulding mandrel 4, and connect the splicing rod 5 to the outermost segment body 41, and drive the segment body 41 to axially escape from the inner hole of the titanium or titanium alloy thick-walled tube 3 ( Figure 8 The multiple segment bodies 41 are driven out from both sides in sequence ( Fig.10 The demoulding operation of the demoulding core rod 4 is completed.

[0051] The principle of the present invention is: when using the demolding core rod 4 (forging and forming the thick-walled tube 3), multiple segmented bodies 41 are spirally sleeved on the splicing rod 5 in sequence, and then the splicing rod 5 is integrally inserted into the center hole of the thick-walled tube 1 blank, and then the outer wall of the thick-walled tube 1 is axially forged by a radial forging machine, so that the wall thickness of the thick-walled tube 1 is reduced and the axial length is increased. After the thick-walled tube 3 is formed, the splicing rod 5 is disassembled and connected to the outermost segmented body 41. A driving external force is applied axially outward by the splicing rod 5 to drive the single segmented body 41 to close and disengage from the thick-walled tube 3, thereby disassembling multiple segmented bodies 41 from both sides in sequence, and the demolding operation of the demolding core rod 4 is completed.

[0052] The above shows and describes the basic principle, main features and advantages of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention claimed.

Claims

1. A demoulding mandrel for forging a titanium or titanium alloy thick-walled tube, characterized in that: The demoulding mandrel is inserted into the middle hole of the thick-walled tube blank for forming the titanium and titanium alloy thick-walled tube body. After the thick-walled tube blank is formed into the titanium and titanium alloy thick-walled tube body structure, the demoulding mandrel body can reduce the contact friction between it and the titanium and titanium alloy thick-walled tube body; The demoulding mandrel is divided into a splicing structure of multiple segmented bodies, and the lengths of the segmented bodies increase in sequence from the center of the demoulding mandrel toward both sides; A splicing rod is commonly provided in the plurality of segment bodies, and when the splicing rod is connected, the end faces of the adjacent segment bodies are in contact with each other; The splicing rod is a screw rod structure connected to each of the segmented bodies by threads; One end of each segmented body located in the direction of separation from the titanium and titanium alloy thick-walled tube is configured as an arc surface structure, and the other end is configured as an arc groove structure matching the end of the arc surface structure of the adjacent segmented body.

2. A demoulding method for a titanium and titanium alloy thick-walled tube forging demoulding mandrel, characterized in that: The following steps are involved: S1, splicing all the segmented bodies by a splicing rod and making the side walls of adjacent segmented bodies butt against each other to form a demoulding core rod; S2, inserting the demoulding mandrel into the center hole of the thick-walled tube blank; S3, under the support of the demoulding mandrel on the inner hole of the thick-walled tube blank, a forging force is applied to the outer wall of the thick-walled tube blank by a radial forging machine to form a titanium or titanium alloy thick-walled tube body; S4, disassemble the splicing rod and the demoulding core rod, and connect the splicing rod to the outermost segmented body, drive the segmented body axially out of the inner hole of the titanium and titanium alloy thick-walled tube body, thereby driving multiple segmented bodies out in turn to complete the demoulding operation of the demoulding core rod.

3. The demoulding method according to claim 2, characterized in that: In step S4, the segmented bodies on both sides are respectively removed from both sides with the center of the demoulding core rod as a reference.

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