A spinning sealing process method and equipment

Abstract

The present invention belongs to the technical field related to the plastic forming of metal materials, and discloses a spinning sealing process method and equipment, wherein the method includes: firstly, the closing section of the blank to be sealed is subjected to diameter reduction spinning through the motion of a rotary wheel, until the port of the closing section is closed; then, a stir friction welding device is used, and after the device reaches a set rotation speed, the material at the port of the closing section is fed and stirred, and the material at the port of the closing section is subjected to stir friction welding to obtain the desired sealing part. The present invention breaks the original interface at the sealing part through the extrusion of the rotary wheel combined with the stir friction welding tool, so that the material is directly stirred, thereby causing strong plastic deformation. Under the strong stirring action, the material at the sealing part can undergo dynamic recrystallization, forming a fine, equiaxed recrystallized structure, so that a strong metallurgical bond is formed between the interfaces, and finally a dense solid phase welding point is formed at the sealing part, which can effectively improve the sealing performance and pressure bearing capacity of the sealing part after forming.

Description

Technical Field

[0001] The present invention belongs to the technical field related to the plastic forming of metal materials, and more specifically, relates to a spinning sealing process method and equipment. Background Art

[0002] As thin-walled rotating body structural parts, tube / cylindrical sealing parts are widely used in aerospace, weapon manufacturing, transportation, daily applications and other fields due to their light weight, good sealing and high structural strength. Spin forming, as a continuous local plastic forming process, is more efficient, practical and economical in the processing and production of such parts due to its high material utilization, low forming force, simple process equipment and no welds.

[0003] Specifically, according to the shape characteristics of the sealing part, when the hollow rotating body part has the best plastic temperature, the tube end is slowly shrunk by the continuous swing of the spinning wheel in the horizontal plane, and finally the sealing of the part is completed through multiple rounds of shrinking spinning. This spinning method is generally used for forming the bottom, bottleneck, accumulator and pointed head of high-pressure gas cylinders such as shells and similar shaped parts with pipes or hollow semi-formed parts with bottoms as blanks. However, after the parts are sealed, the existing spinning sealing process has problems such as poor sealing and weak pressure bearing capacity due to the unsatisfactory combination of port materials. Summary of the invention

[0004] In view of the above defects or improvement needs of the prior art, the present invention provides a spin-forming sealing process method and equipment, which solves the problem that after the parts are sealed in the existing spin-forming sealing process, the parts have poor sealing and weak pressure bearing capacity due to unsatisfactory bonding of the port materials.

[0005] To achieve the above object, according to one aspect of the present invention, a spinning sealing process is provided, comprising:

[0006] S1, reducing the diameter of the closing section of the blank to be sealed by spinning the wheel until the port of the closing section is closed;

[0007] S2, using a friction stir welding device, feeding and stirring the material at the end of the closing section after it reaches a set speed, and performing friction stir welding on the material at the end of the closing section to obtain the required sealing component.

[0008] According to the spin-sealing process provided by the present invention, S2 specifically includes:

[0009] The friction stir welding device is used to stir the material at the end of the closing section, and after the stirring reaches a set time, the friction stir welding device gradually withdraws the material at the end of the closing section;

[0010] During the withdrawal of the friction stir welding device, the rotary wheel performs a forward rotation motion to replenish material at the port.

[0011] According to the spinning sealing process method provided by the present invention, the movement path of the spinning wheel shrinking in S1 is specifically as follows: the first pass or the first few passes adopts reverse rotation, the middle passes adopt a mixture of forward rotation and reverse rotation, and the last pass adopts forward rotation; wherein, for the sealing parts requiring the port of the closing section to be thickened, the middle passes are mainly reverse rotation.

[0012] According to the spinning sealing process provided by the present invention, the process of closing the port of the closing section in S1 specifically includes: closing the port gap diameter to less than 1 mm;

[0013] And / or, the withdrawal speed of the friction stir welding device in S2 is 30 to 120 mm / min.

[0014] According to the spin-sealing process method provided by the present invention, the rotating wheel includes two opposite side surfaces and a head connected between the two side surfaces, the head of the rotating wheel is set to a rounded corner, and the portion where the side surface of the rotating wheel and the head meet is set to a plane or to a shape that matches the closing section; as the plastic properties of the blank to be sealed increase, the radius of the rounded corner gradually increases.

[0015] According to the spinning sealing process method provided by the present invention, before S1, it also includes: S00, installing the blank to be sealed on the main shaft, so that the closing section of the blank to be sealed is in a suspended state; S01, heating the closing section until the forming temperature of the blank to be sealed is reached, and the blank to be sealed rotates integrally with the main shaft during the heating process;

[0016] And / or, after performing friction stir welding on the material at the end of the closing section in S2, the method further includes: after the friction stir welding device is completely withdrawn, the rotary wheel moves to the end of the closing section and performs an over-axis movement to grind the weld point.

[0017] According to the spinning sealing process provided by the present invention, the rotation speed of the main shaft during the heating process of S01 is less than the rotation speed of the main shaft during the forming process of S1 and S2;

[0018] The spindle speed during the forming process of S1 and S2 was 300 to 3500 rev / min;

[0019] The relative rotation speed between the friction stir welding device and the main shaft is 300-3000 rev / min.

[0020] According to the spin-sealing process provided by the present invention, the friction stir welding device comprises a driving shaft, a shaft shoulder and a stirring needle which are connected in sequence, and the driving shaft drives the shaft shoulder and the stirring needle to rotate integrally;

[0021] The outer surface of the stirring needle is provided with a thread structure, the shape of the thread structure is matched with the rotation direction of the blank to be sealed, and when the rotation direction of the blank to be sealed is clockwise, the thread structure is set as a left-hand thread; and / or the surface of the shoulder facing the blank to be sealed is matched with the port shape of the closing section and is a concave spherical surface; the surface of the shoulder facing the blank to be sealed is provided with a concave and convex structure.

[0022] According to the spin-sealing process method provided by the present invention, the diameter ratio of the stirring needle to the shoulder is 1:3 to 1:5; the length of the stirring needle is 0.1 to 0.5 mm smaller than the thickness at the port of the closing section; the diameter of the stirring needle is 0.9 to 1.1 times the thickness at the port of the closing section; the embedding amount of the shoulder in S2 embedded in the port of the closing section is 0.1 mm to 0.5 mm.

[0023] According to another aspect of the present invention, a spinning sealing process equipment is provided, including a spinning sealing device and a friction stir welding device, wherein the spinning sealing device includes a main shaft, a chuck, a rotary wheel, a rotary wheel frame and a heating device, wherein the main shaft is a hollow structure, the blank to be sealed is fixed in the main shaft through the chuck, the rotary wheel is installed on the rotary wheel frame, and the rotary wheel and the heating device are respectively arranged at positions corresponding to the closing section of the blank to be sealed; the friction stir welding device includes a driving shaft, a shaft shoulder and a stirring needle connected in sequence, the driving shaft drives the shaft shoulder and the stirring needle to rotate as a whole, and the friction stir welding device is coaxially arranged relative to the main shaft;

[0024] It also includes a controller, which is connected to the spin-sealing device and the friction stir welding device respectively, and is used to control the spin-sealing device and the friction stir welding device to perform any of the above-mentioned spin-sealing process methods.

[0025] In general, compared with the prior art, the above technical solutions conceived by the present invention mainly have the following beneficial effects:

[0026] 1. Aiming at the problem of poor sealing and insufficient strength of existing pipe / cylindrical parts after sealing by spinning, a sealing spinning process method is proposed. The original interface of the sealing part is broken by the extrusion of the spinning wheel combined with the stir friction welding tool, so that the material is directly stirred by the stirring head, thereby causing strong plastic deformation. Under the strong stirring action, the material at the sealing part can undergo dynamic recrystallization to form a fine, equiaxed recrystallized structure, so that a strong metallurgical bond is formed between the interfaces, and finally a dense solid phase weld is formed at the sealing part, which can effectively improve the sealing performance and pressure bearing capacity of the sealing part after forming;

[0027] 2. In view of the problems of defects such as pores and cracks in the welding part of the traditional TIG welding and MIG welding during the repair welding of the spinning sealing parts, and the existence of large residual deformation and welding internal stress, the stir friction welding process can make the sealing part integrally formed without the need for additional solder and additional repair welding operations, which is conducive to improving the integrity of the sealing part and thus overcoming the above problems. In addition, since the welding temperature of the stir friction welding does not exceed the melting temperature of the material, it can avoid the problems of slag inclusion, thermal cracks, alloy elements, severe softening of the joint and large deformation of the workpiece, and can be widely used in the sealing of non-ferrous metal parts. In addition, since no solder and protective gas are required during the welding process, no arc light, splashing and toxic gas will be generated, and the welding environment is clean;

[0028] 3. The present invention combines sealing spinning and friction stir welding processes to obtain sealing pipes / cylindrical parts with good sealing performance and strong pressure bearing capacity at the sealing part, which fully combines the characteristics of the two types of processes, and is not a simple combination. The sealing spinning can complete the overall forming of the sealing part, and the "keyhole" left by the stirring needle in the friction stir welding device when the friction stir welding device exits can be avoided by replenishing the material through the positive rotation movement of the rotary wheel, and the high-cost telescopic welding tool is not required; the subsequent over-axis movement of the rotary wheel can grind and deburr the welding points, shortening the subsequent processing cycle;

[0029] 4. For welding of hard-to-deform materials, conventional methods promote material flow by increasing the rotation speed of the stirring needle or using an external heat source or ultrasonic field to increase heat input. The spinning sealing device mentioned in the present invention generally has a spindle speed control system and is convenient for installing a heating device. The friction stir welding device does not need an additional heating device, which reduces the parameter requirements and equipment function requirements of the friction stir welding equipment;

[0030] 5. The concave spherical shoulder with a concave-convex structure on the shoulder surface is used to replace the conventional flat shoulder, which can effectively apply force, increase the friction effect, and control the migration behavior of the surface material, and has a certain ability to contain the flowing material; the stirring needle is a threaded stirring needle, which can stir the material more effectively, break and disperse the interface oxide layer, promote the formation of metallurgical bonding, and is not easy to produce welding defects;

[0031] 6. The present invention can add a simple stirring friction device based on the existing spinning sealing device, without the need for additional equipment, and can achieve integrated processing of diameter reduction and sealing, without the need for post-spinning welding, thus saving working procedures and facilitating commercial applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a flow chart of a spinning sealing process method according to an embodiment of the present invention;

[0033] Figure 2 is a schematic diagram of a spinning sealing process equipment in an embodiment of the present invention;

[0034] Figure 3 Schematic diagram of the process of friction stir welding-assisted pipe / cylindrical part spinning and sealing in an embodiment of the present invention;

[0035] Figure 4 It is a flowchart of a specific application example in an embodiment of the present invention;

[0036] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0037] 1-spindle; 2-chuck; 3-heating device; 4-blank to be sealed; 5-stirring needle; 6-driving shaft; 7-driving motor; 8-rotating wheel; 9-rotating wheel frame. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0039] See also Figure 1 The present embodiment 1 provides a spinning sealing process method, the spinning sealing process method comprising:

[0040] S1, firstly, the closing section of the blank 4 to be sealed is spun by the rotating wheel 8 until the port of the closing section is closed;

[0041] S2, then using a friction stir welding device, after it reaches a set speed, feeding and stirring the material at the end of the closing section, and performing friction stir welding on the material at the end of the closing section to obtain the desired sealing product.

[0042] This embodiment introduces the stir friction welding process on the basis of the conventional rotary wheel spinning sealing method to complete the sealing of the blank. The blank 4 to be sealed can be a pipe blank or a cylindrical blank. The closing section is the part of the blank where the diameter changes during the sealing process. The end of the closing section is the part where the seal is finally formed.

[0043] That is, the conventional spinning wheel 8 is first used to spin the closing section of the blank to close the diameter. When the diameter is spun to close the port of the closing section, the stir friction welding process is introduced, and the stir friction welding device is fed into the material at the port of the embedded closing section, and the material at the port is strongly mechanically stirred by rotation, which can cause strong plastic deformation. And the spinning process is usually carried out at high temperature when the blank has good plasticity. Therefore, at high temperature, due to the strong stirring of the stir friction welding device, the material at the sealing part, i.e., the port, can also undergo dynamic recrystallization, forming a fine, equiaxed recrystallized structure, forming a strong metallurgical bond between the interfaces, and finally forming a dense solid phase welding point at the sealing part, which can effectively improve the sealing and pressure bearing capacity of the sealed part.

[0044] By combining a friction stir welding device to vigorously mechanically stir the blank port, a stronger metallurgical bond is formed at the interface of the seal of the workpiece, resulting in a denser solid phase weld, which can effectively improve the sealing and pressure-bearing capacity of the seal of the workpiece. The spinning process is formed in one step, avoiding re-processing such as repair welding after spinning, which is conducive to shortening the processing cycle and reducing costs.

[0045] Furthermore, S2 specifically includes:

[0046] The friction stir welding device is used to stir the material at the end of the closing section, and after the stirring reaches a set time, the friction stir welding device gradually withdraws the material at the end of the closing section;

[0047] During the withdrawal of the friction stir welding device, the rotary wheel 8 performs a positive rotation motion to fill the port. That is, when the friction stir welding device starts to withdraw the material at the port of the closing section, the rotary wheel 8 starts to perform a positive rotation motion. Positive rotation can bring the sealing end together, so that the blank is squeezed toward the port, achieving the "filling" effect. This filling does not mean adding additional solder, but adjusting the flow distribution state of the blank through the positive rotation motion of the rotary wheel 8, so that during the withdrawal of the friction stir welding device from the sealing portion, the blank is squeezed and flows toward the sealing portion, so that the blank can timely fill the gap when the friction stir welding device is withdrawn, achieving the filling effect and ensuring the density of the sealing portion.

[0048] Furthermore, the withdrawal speed of the friction stir welding device in S2 is 30-120 mm / min. The withdrawal speed is determined according to the feeding speed of the rotary wheel 8 and the sealing wall thickness, with the purpose of completing the forward rotation feeding of the rotary wheel 8 when the stirring needle of the friction stir welding device completely withdraws from the port material, so as to ensure that the sealing part is filled with material.

[0049] The specific motion path of the shrinking spinning of the rotary wheel 8 described in S1 is: the first pass or the first few passes adopts reverse rotation, the middle pass adopts a mixture of forward rotation and reverse rotation, and the last pass adopts forward rotation; among them, for the sealing parts that require the thickening of the port of the closing section, the middle pass adopts mainly reverse rotation. The first pass or the first few passes of the rotary wheel 8 are reversely rotated from the port to prevent the edge of the open end from generating an outward flange; the last pass adopts forward rotation to achieve material filling. The ratio of forward and reverse rotation in the middle pass is adjusted according to different situations. For the parts that require the mouth or bottom, i.e. the sealing part to be thickened, reverse rotation should be used as the main method. This is because the material will accumulate behind the rotary wheel, and the mouth can be thickened by reverse rotation.

[0050] Furthermore, if productivity is to be improved, the intermediate passes can be performed alternately in forward and reverse rotations.

[0051] In S1, until the port of the closing section is closed, specifically, until the port gap diameter is less than 1 mm; that is, when it is detected that the diameter of the gap at the port is less than 1 mm, the spinning operation of the rotary wheel 8 can be stopped, and the friction stir welding device can be started. After its rotation speed reaches the set rotation speed, it is fed forward to the embedded port material for stirring. When the friction stir welding device is started, the rotary wheel 8 can be moved to a position of the closing section away from the port to avoid interference with the friction stir welding device and facilitate the positive rotation movement of the last pass.

[0052] In this embodiment, the shape of the roller 8 is determined according to the shape and geometric dimensions of the workpiece to be formed. The roller 8 includes two opposite side surfaces and a head connected between the two side surfaces. The head of the roller 8 is set as a fillet, and the part where the side surface of the roller 8 and the head meet is set as a plane or a shape that matches the closing section. The radius of the fillet is generally 1 to 3 times the thickness of the blank. As the plasticity of the blank 4 to be sealed increases, the radius of the fillet gradually increases. For materials with good plasticity, such as copper, aluminum, and low-carbon steel, the fillet radius takes an upper limit to reduce local stress concentration in the material; for materials with poor plasticity, such as titanium alloy, high-carbon steel, and stainless steel, the lower limit is taken to increase local pressure and promote material flow.

[0053] Before S1, it also includes: S00, installing the blank 4 to be sealed on the main shaft 1, so that the closing section of the blank 4 to be sealed is in a suspended state; S01, heating the closing section until the forming temperature of the blank 4 to be sealed is reached, and the blank 4 to be sealed rotates integrally with the main shaft 1 during the heating process.

[0054] According to the shape and size of the workpiece to be formed and the part to be formed, the corresponding mechanical or hydraulic clamps are used to fix the pipe / cylindrical part on the spinning machine, and the part to be formed is allowed to extend out and hang in the air; for smaller-sized parts and other situations where it is difficult to use a core mold, the pipe / cylindrical part can be installed in the hollow spindle 1 and the chuck 2, and the part to be formed is allowed to extend out and hang in the air, and then clamped using the chuck 2.

[0055] In S01, flame or induction heating is used to locally heat the part to be formed, i.e., the closing section, of the pipe or cylindrical blank. The forming temperature in S01 is generally 20 to 100°C below the recrystallization temperature of the material. For some difficult-to-form materials with high yield strength and hardness, such as high-strength steel, titanium alloy, refractory metals, etc., the heating temperature may be above the recrystallization temperature, but must be lower than the phase change temperature. The forming temperature is between the brittle temperature transition point of the material and the phase change temperature of the material, and the recrystallization temperature of the material is within this temperature range.

[0056] After the friction stir welding is performed on the port of the closing section in S2, the method further includes: after the friction stir welding device is completely withdrawn, the side of the rotary wheel 8 moves to the port of the closing section and performs an over-axis movement to grind the weld point. The rotary wheel 8 performs a positive rotational movement while the friction stir welding device is axially withdrawn. After the friction stir welding device is completely withdrawn, the side of the rotary wheel 8 reaches the sealing weld point, and finally the rotary wheel 8 performs an over-axis movement to grind the weld point.

[0057] In some specific embodiments, the rotation speed of the spindle 1 during the heating process of S01 is less than the rotation speed of the spindle 1 during the forming processes of S1 and S2; the rotation speed of the spindle 1 during the forming processes of S1 and S2 is 300-3500 rev / min.

[0058] The operating parameters of the friction stir welding device during operation include: the relative rotation speed of the friction stir welding device and the spindle 1 is 300-3000 rev / min. The actual rotation direction of the friction stir welding device is opposite to that of the blank.

[0059] During the heating process, the speed of the spindle 1 can be half of the speed of the spindle 1 during the forming process. The heating process can use an induction coil or oxyacetylene to heat the part to be formed; during the heating process, the part rotates slowly until the part reaches its appropriate deformation temperature. The speed of the spindle 1 during the forming process is set to 300-3500rev / min according to the wall thickness and diameter of the part. In order to maintain stability during forming, the speed adjustment of the spindle 1 generally decreases with the increase of the diameter and wall thickness of the blank 4 to be sealed; that is, the smaller the diameter, the faster the speed; the smaller the wall thickness, the faster the speed.

[0060] Then the rotary wheel 8 is spun reciprocatingly in succession according to the profiling plate, program control or numerical control program, and the feed speed of the rotary wheel 8 is selected to be 800-1200mm / min; according to the general process, the rotary wheel 8 is spun in reverse from the port in the first pass to prevent the edge of the open end from generating an outer flange, and then reciprocating multiple passes of forward and reverse swinging and radial feed spinning are performed. Due to the continuous and step-by-step spinning, the diameter of the end of the blank is reduced, so that it is closed and fused together, and the sealing gap diameter is required not to exceed 1mm.

[0061] Specifically, the friction stir welding device comprises a driving shaft 6, a shaft shoulder and a stirring needle 5 which are connected in sequence, and the driving shaft 6 drives the shaft shoulder and the stirring needle 5 to rotate integrally;

[0062] In order to enhance the stirring effect, the outer surface of the stirring needle 5 is provided with a thread structure, the shape of which matches the rotation direction of the blank 4 to be sealed. When the rotation direction of the blank 4 to be sealed is clockwise, the thread structure is set as a left-hand thread; and / or, the surface of the shoulder facing the blank 4 to be sealed matches the shape of the port of the closing section and is a concave spherical surface. Different geometric morphologies can be added to the shoulder surface, for example, the surface of the shoulder facing the blank 4 to be sealed is provided with a concave-convex structure, which can be a spiral groove structure. The stirring needle 5 is conical or truncated cone shaped.

[0063] The specific setting of the thread structure on the outer surface of the stirring needle 5 can not only enhance the stirring effect, but also, through the specific thread direction setting that matches the rotation direction of the blank, the thread groove can play the role of a connecting channel during the stirring process of the stirring needle 5 embedded in the port material, which is conducive to the reflux of the port material and avoids the material from flowing out and splashing. The setting of the concave-convex structure on the shoulder surface is conducive to improving the embedding stability, enhancing the stirring, and having a certain ability to contain the overflowing material, improving the migration behavior of the surface material.

[0064] The dimensions of the main working parts of the friction stir welding device are as follows: the diameter ratio of the stirring needle 5 to the shaft shoulder is 1:3 to 1:5; the length of the stirring needle 5 is 0.1 to 0.5 mm smaller than the thickness at the end of the closing section; the diameter of the stirring needle 5 is 0.9 to 1.1 times the thickness at the end of the closing section; the amount of the shaft shoulder embedded in the end of the closing section in S2 is 0.1 mm to 0.5 mm. The sum of the embedded amount of the shaft shoulder and the length of the stirring needle 5 is less than or equal to the thickness at the end.

[0065] Specifically, for thin-walled blanks, the shoulder pressing amount, i.e. the embedding amount, is 0.1 mm to 0.3 mm, and for medium-thick blanks it is no more than 0.5 mm.

[0066] When the rotary wheel 8 is spun to reduce the diameter of the port gap to less than 1 mm, the friction stir welding device is turned on after the rotation direction of the welding tool is set. When the welding tool speed reaches the set speed, the stirring device is fed forward until the shaft shoulder is pressed down to a suitable position. After the stirring needle 5 completes the stirring of the material, the stirring device begins to slowly withdraw. At the same time, the rotary wheel 8 is fed forward to replenish the material. After the stirring device is completely withdrawn, the rotary wheel moves over the axis to grind and correct the weld. During the spinning process, a heating device 3 such as a flame spray gun is used to heat the deformation zone. The heating device 3 and the rotary wheel can move axially as a whole to heat the deformation zone in real time.

[0067] This embodiment 2 provides a spinning sealing process equipment, referring to Figure 2 The spinning sealing process equipment includes a spinning sealing device and a friction stir welding device, the spinning sealing device includes a main shaft 1, a chuck 2, a rotating wheel 8, a rotating wheel frame 9 and a heating device 3, the main shaft 1 is a hollow structure, the blank 4 to be sealed is fixed in the main shaft 1 through the chuck 2, the rotating wheel 8 is installed on the rotating wheel frame 9, the rotating wheel 8 and the heating device 3 are respectively arranged at the corresponding positions of the closing section of the blank 4 to be sealed; the friction stir welding device includes a driving shaft 6, a shoulder and a stirring needle 5 connected in sequence, the driving shaft 6 drives the shoulder and the stirring needle 5 to rotate as a whole, and the friction stir welding device is coaxially arranged relative to the main shaft 1; the driving shaft 6 can be connected to a driving motor 7 and rotate under the drive of the driving motor 7.

[0068] The spin-sealing process equipment also includes a controller, which is connected to the spin-sealing device and the friction stir welding device respectively, and is used to control the spin-sealing device and the friction stir welding device to perform the spin-sealing process method described in any of the above embodiments.

[0069] The following are specific application examples:

[0070] The sealed gas cylinder is made of 2A12 aluminum alloy cylindrical parts with a diameter of 400mm, a length of 1200mm and a wall thickness of 15mm as the blank. The bottom wall thickness of the gas cylinder is required to be thickened, and the sealing part has good airtightness and strong pressure bearing capacity. The specific steps include the following:

[0071] Step (1): Install the rotating wheel 8 on the rotating wheel frame 9 for fixing, wherein the rotating wheel 8 is made of hot working die steel 4Cr5MoSiV1 with good red hardness and high temperature resistance, the rotating wheel diameter is 600mm, and the fillet radius is 15mm; install the tube blank into the hollow main shaft 1 of the spinning equipment, let the part to be formed extend out and hang in the air, and then clamp it with the chuck 2.

[0072] Step (2): Turn on the spindle 1 of the spinning equipment to drive the cylindrical part to rotate synchronously. The rotation direction is clockwise, and the spindle 1 speed is set to 175 rev / min; turn on the heating device 3 for flame heating until the temperature of the cylindrical part reaches 350°C. After the temperature stabilizes, adjust the spindle 1 speed to 350 rev / min to prepare for diameter reduction spinning.

[0073] Step (3): According to the material and size of the cylindrical part, the feed rate of the rotary wheel 8 is set to 0.75 mm / r; the numerical control program is set to control the rotary wheel 8 to retract and rotate, such as Figure 3 As shown in (a), in order to avoid the outer edge of the blank opening end, the first pass of the rotating wheel 8 is reversely rotated; Figure 3As shown in (b), in the middle pass, the wheel rotates forward and reverse alternately to speed up production efficiency. The wheel track gradually transitions from A to B, the swing angle increases, and the swing radius gradually decreases. Because this type of component requires a thicker bottom wall, the number of reverse rotation passes needs to be increased; finally, in order to avoid material bulging, forward rotation is used when closing, and the wheel 8 swings until the end material overlaps, as shown in FIG. Figure 3 The specific feed amount and path of the spinning wheel during the spinning and sizing process are set in the conventional setting process of the spinning process, and the details will not be repeated.

[0074] Step (4): Figure 3 As shown in (d), the friction stir welding device is started, the welding tool rotates counterclockwise, the speed is 350rev / min, that is, the relative speed between the stirring head and the cylindrical part is 700rev / min; after reaching the set speed, the stirring device is axially fed at a speed of 600mm / min until the shaft shoulder is pressed into the port of the cylindrical part by 0.5mm, and the pressure is maintained for 10s to ensure that the stirring head and the port material are fully extruded and stirred to break and disperse the interface oxide layer; Figure 3 As shown in (e), the stirring device slowly exits the port of the cylindrical part at a speed of 100 mm / min, while the rotary wheel 8 rotates forward to replenish the material. After the stirring head completely exits the port, the rotary wheel 8 moves to the port of the cylindrical part; Figure 3 As shown in (f), when the stirring device is withdrawn to a safe distance, the rotary wheel 8 moves across the axis and uses its side surface to grind and remove burrs on the sealing welding point.

[0075] In step (4), in order to make the friction stir welding tool have a longer service life under high temperature and high wear conditions, heat-treated mold steel is selected as the material; the stirring needle 5 is 12 mm long and has a triangle shape with a left thread to ensure that the material migrates and flows downward in the thickness direction; the shoulder diameter is 40 mm, which is a concave spherical shape and has a special thread pattern on the surface, which has a certain ability to wrap the overflow material and improve the migration behavior of the surface material.

[0076] The embodiment of the present invention discloses a spinning sealing process method and equipment, referring to Figure 4 , wherein the process mainly includes the following steps: a clamping and fixing step, in which a rotary wheel 8 is designed according to the shape of the head, the rotary wheel 8 is installed on the machine tool, and then the tube / cylindrical part is clamped and fixed by the chuck 2 and the center frame of the lathe; a port heating step, in which a heating device 3 is used to heat the sealing part of the above-mentioned blank until it reaches a suitable forming temperature, and the blank and the main shaft 1 rotate synchronously during the heating process; a spinning step, in which the rotation speed of the main shaft 1 is adjusted so that the rotary wheel 8 moves along a specified path, and the blank is spun with a reduced diameter until the blank port overlaps; a sealing step, in which the stirring friction device is started, and after reaching the set rotation speed, it is fed forward to stir the port material, and when the device exits, the rotary wheel 8 moves along a specified path to replenish the port material to obtain the required sealed part.

[0077] In the initial stage of forming, the track of the rotary wheel 8 is set to reduce the diameter of the tube / cylinder blank and make the rotary wheel reciprocate according to the specified track; after spinning until the ports of the workpiece overlap, the friction stir welding device starts to rotate and feed forward to fully mechanically stir the ports. After holding for a certain period of time, the stirring device starts to withdraw the workpiece. At the same time, the rotary wheel moves toward the sealing position according to the track to replenish the material, and finally completes the sealing of the tube / cylindrical part. The present invention uses friction stir welding to assist the spinning and sealing of the tube / cylindrical part to solve the problems of poor sealing of the workpiece, weak pressure bearing capacity, and the need for welding after sealing. It can be integrated into production and processing with high production efficiency.

[0078] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A spinning sealing process, characterized in that: include: S1, reducing the diameter of the closing section of the blank to be sealed by spinning the wheel until the port of the closing section is closed; S2, using a friction stir welding device, feeding and stirring the material at the end of the closing section after the device reaches a set speed, and performing friction stir welding on the material at the end of the closing section to obtain the desired sealing part; S2 specifically includes: The friction stir welding device is used to stir the material at the end of the closing section, and after the stirring reaches a set time, the friction stir welding device gradually withdraws the material at the end of the closing section; During the withdrawal of the friction stir welding device, the rotary wheel performs a positive rotation motion to fill the port. During the withdrawal of the friction stir welding device from the sealing portion, the blank is squeezed and flows toward the sealing portion, so that the blank can timely fill the gap when the friction stir welding device is withdrawn.

2. The spinning sealing process according to claim 1, characterized in that: The specific motion path of the spinning process of the rotary wheel shrinking in S1 is as follows: the first pass or the first few passes adopts reverse rotation, the middle passes adopt a mixture of forward rotation and reverse rotation, and the last pass adopts forward rotation; wherein, for the sealing parts requiring the thickening at the port of the closing section, the middle passes are mainly reverse rotation.

3. The spinning sealing process according to claim 1, characterized in that: In S1, the process of closing the port of the closing section specifically includes: closing the port gap diameter to less than 1 mm; And / or, the withdrawal speed of the friction stir welding device in S2 is 30-120 mm / min.

4. The spinning sealing process according to claim 1, characterized in that: The rotating wheel includes two opposite side surfaces and a head connected between the two side surfaces. The head of the rotating wheel is set to a rounded corner. The portion where the side surface of the rotating wheel meets the head is set to a plane or a shape that matches the closing section. As the plastic properties of the blank to be sealed increase, the radius of the rounded corner gradually increases.

5. The spinning sealing process according to any one of claims 1 to 4, characterized in that: Before S1, the process also includes: S00, mounting the blank to be sealed on the main shaft so that the closing section of the blank to be sealed is in a suspended state; S01, heating the closing section until the forming temperature of the blank to be sealed is reached, and the blank to be sealed rotates integrally with the main shaft during the heating process; And / or, after performing friction stir welding on the material at the end of the closing section in S2, the method further includes: after the friction stir welding device is completely withdrawn, the rotary wheel moves to the end of the closing section and performs an over-axis movement to grind the weld point.

6. The spinning sealing process according to claim 5, characterized in that: The spindle speed during the heating process of S01 is lower than that during the forming process of S1 and S2; The spindle speed during the forming process of S1 and S2 was 300~3500rev / min; The relative rotation speed of the friction stir welding device and the main shaft is 300-3000 rev / min.

7. The spinning sealing process according to any one of claims 1 to 4, characterized in that: The friction stir welding device comprises a driving shaft, a shaft shoulder and a stirring needle which are connected in sequence, and the driving shaft drives the shaft shoulder and the stirring needle to rotate integrally; The outer surface of the stirring needle is provided with a thread structure, the shape of the thread structure is matched with the rotation direction of the blank to be sealed, and when the rotation direction of the blank to be sealed is clockwise, the thread structure is set as a left-hand thread; and / or the surface of the shoulder facing the blank to be sealed is matched with the port shape of the closing section and is a concave spherical surface; the surface of the shoulder facing the blank to be sealed is provided with a concave and convex structure.

8. The spin-sealing process according to claim 7, characterized in that: The diameter ratio of the stirring needle to the shoulder is 1:3~1:5; the length of the stirring needle is 0.1~0.5mm smaller than the thickness at the port of the closing section; the diameter of the stirring needle is 0.9~1.1 times the thickness at the port of the closing section; the embedding amount of the shoulder in S2 into the port of the closing section is 0.1mm~0.5mm.

9. A spinning sealing process equipment, characterized in that: It comprises a spinning sealing device and a friction stir welding device, wherein the spinning sealing device comprises a main shaft, a chuck, a rotary wheel, a rotary wheel frame and a heating device, wherein the main shaft is a hollow structure, the blank to be sealed is fixed in the main shaft through the chuck, the rotary wheel is mounted on the rotary wheel frame, and the rotary wheel and the heating device are respectively arranged at positions corresponding to the closing section of the blank to be sealed; the friction stir welding device comprises a driving shaft, a shaft shoulder and a stirring needle connected in sequence, the driving shaft drives the shaft shoulder and the stirring needle to rotate as a whole, and the friction stir welding device is coaxially arranged relative to the main shaft; It also includes a controller, which is connected to the spin-sealing device and the friction stir welding device, respectively, and is used to control the spin-sealing device and the friction stir welding device to perform the spin-sealing process method described in any one of claims 1-8.

Images