A cylindrical filter forming and welding tooling and welding method

Abstract

The present invention discloses a cylindrical filter forming and welding tooling and a welding method, which relates to the technical field of welding, and includes a folding net pressing ring spot welding module, an end ring spot welding and fixing module, and a pulsed laser welding auxiliary fixing seat; the folding net module includes a folding net rod and a spot welding fixing seat, the spot welding fixing seat is provided with a groove, the folding net rod is inserted and matched with the groove, and there is a gap between the outer side wall of the folding net rod and the inner side wall of the groove; the end ring spot welding and fixing module includes a positioning tooling female seat and a positioning tooling, the positioning tooling female seat is provided with a plurality of spot welding windows, the positioning tooling female seat is internally provided with a circular opening cavity, the spot welding windows are communicated with the circular opening cavity, and the positioning tooling is threadedly connected to the opening of the circular opening cavity; the pulsed laser welding auxiliary fixing seat has a shrinkage clamping middle seam, and one end of the pulsed laser welding auxiliary fixing seat is provided with a clamping groove, and the clamping groove is matched with the size of the end ring. The problems of easy damage, inconvenient clamping, and inaccurate welding positioning during the forming and welding of the existing cylindrical filter are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of welding, and particularly to a forming and welding tooling for a cylindrical filter and a welding method thereof. Background Art

[0002] With the continuous development of the aerospace industry, the requirements for lightweight design of valves are very strict. The original filter has a large volume and can no longer meet the current development needs. Therefore, a new type of cylindrical filter has emerged. This type of cylindrical filter has a small volume and is used at the inlet of precision valves, which can effectively reduce its volume and is beneficial to the weight reduction of the valves. However, the filter screen used in this type of filter assembly is relatively thin, about 0.1 mm, and is in a sheet shape. It is easy to be damaged during forming by conventional processing methods. In addition, due to its structural limitations, its structural dimensions are small, and it cannot be clamped by a conventional clamping chuck. Moreover, when performing pulsed laser welding directly during forming and welding, it is impossible to ensure the accurate welding position relationship, and a complete circumferential weld cannot be formed. Also, due to the thin filter screen, the problem of poor welding quality is likely to occur. The present invention adds the requirement of spot welding before pulsed laser welding and realizes the welding of this type of filter assembly through an auxiliary welding tooling. Summary of the Invention

[0003] Aiming at the deficiencies in the above background art, the present invention provides a forming and welding tooling for a cylindrical filter and a welding method thereof, which solve the problems of easy damage, inconvenient clamping, and inaccurate welding positioning during the forming and welding of the cylindrical filter in the prior art.

[0004] The technical solution of the present invention is realized as follows: A forming and welding tooling for a cylindrical filter, characterized in that it includes a net-folding pressing ring spot welding module for forming and welding the cylindrical filter, an end ring spot welding and fixing module, and a pulsed laser welding auxiliary fixing seat; the net-folding module includes a net-folding rod and a spot welding fixing seat. The spot welding fixing seat is provided with a groove, and the net-folding rod is inserted and matched with the groove. A gap is left between the outer side wall of the net-folding rod and the inner side wall of the groove; the end ring spot welding and fixing module includes a positioning tooling female seat and a positioning tooling. The positioning tooling female seat is provided with a plurality of spot welding windows. The positioning tooling female seat internally has a circular opening cavity, and the spot welding windows are communicated with the circular opening cavity. The positioning tooling is threadedly connected to the opening of the circular opening cavity, and the end of the positioning tooling and the inner bottom surface of the circular opening cavity jointly clamp and press the cylindrical filter; the pulsed laser welding auxiliary fixing seat has a shrinkage clamping middle seam, and one end of the pulsed laser welding auxiliary fixing seat is provided with a clamping groove, and the clamping groove matches the size of the cylindrical filter.

[0005] Preferably, the cylindrical filter includes a filter net, an end ring, and a pressing ring, which are respectively fixed on both sides of the filter net; the filter net is a cup-shaped filter net, and an outer eaves is provided on the outside of the opening of the cup-shaped filter net, and the outer eaves and the pressing ring are respectively arranged on both sides of the outer eaves; the end ring is a two-stage stepped ring, wherein the outer ring surface of the first-stage stepped ring with a smaller diameter is connected to the inner side wall of the cup-shaped filter net, and the side wall of the first-stage stepped ring with a larger diameter is connected to the outer eaves.

[0006] Preferably, the folding net rod is a two-stage stepped shaft, the thinner first-stage stepped shaft of the two-stage stepped shaft is inserted and matched with the groove, the spot welding fixing seat is a frustum-shaped seat body, the groove is opened in the middle of the frustum-shaped seat body, and a clamping groove corresponding to the pressing ring is provided at the opening of the groove.

[0007] Preferably, one end of the positioning tooling female seat is provided with a connection hole communicating with the circular opening cavity, the connection hole is located at the center of the inner bottom surface of the circular opening cavity, and the spot welding window is flush with the inner bottom surface of the circular opening cavity; the positioning tooling includes a positioning seat, one end of the positioning seat is provided with a positioning hole, the inner diameter of the positioning hole is larger than the outer diameter of the cup-shaped filter net, the outer side wall of the positioning seat is threadedly connected with the inner wall of the circular opening cavity, and clamping planes are provided on the outer side walls of both the positioning seat and the positioning tooling female seat.

[0008] Preferably, the spot welding window is a long strip-shaped waist hole and at least two are provided, and a plurality of long strip-shaped waist holes are arranged at equal intervals in the circumferential direction on the positioning tooling female seat.

[0009] Preferably, the pulsed laser welding auxiliary fixing seat is an annular seat body, the shrinkage clamping middle seam penetrates through the side wall of the annular seat body along the length direction, a C-shaped retaining ring is provided in the middle of the annular seat body, the C-shaped retaining ring divides the annular seat body into a clamping part and a clamping part, the clamping groove is located at the end face of the clamping part, the diameter of the clamping part is smaller than that of the clamping part, and the wall thickness of the clamping part is less than or equal to the wall thickness of the clamping part.

[0010] A welding method using the above cylindrical filter forming and welding tooling includes the following steps:

[0011] Step 1: Lay the sheet-shaped circular filter net flat on the end face of the folding net rod, fold the sheet-shaped circular filter net along the folding net rod into a cup-shaped filter net, then place the pressing ring on the spot welding fixing seat, insert the folding net rod carrying the cup-shaped filter net into the pressing ring and into the groove until the cup-shaped filter net is in close contact with the bottom of the groove.

[0012] Step 2: Use tweezers to turn outwards the part of the cup-shaped filter net that exceeds the pressing ring so that it fits against the end face of the pressing ring to form an outer eaves, and perform resistance welding fixation on the outer eaves and the end face of the pressing ring. After the welding fixation is completed, trim the part of the outer eaves that exceeds the side wall of the pressing ring.

[0013] Step 3: Insert and fit the end ring with the cup-shaped filter net so that the outer eaves are located between the end ring and the pressing ring to form a semi-finished cylindrical filter. Then, install the semi-finished cylindrical filter in the circular opening cavity inside the positioning tooling female base, and make the outer eaves correspond to the spot welding window. Thread the positioning tooling into the opening of the circular opening cavity, and use the end face of the positioning tooling and the inner bottom surface of the circular opening cavity to press and hold the end ring, the outer eaves, and the pressing ring. Then, perform spot welding between the end ring and the pressing ring from the spot welding window using resistance welding.

[0014] Step 4: Clamp the semi-finished cylindrical filter after spot welding on the pulsed laser welding auxiliary fixing seat. Subsequently, clamp the pulsed laser welding auxiliary fixing seat on the chuck of the welding equipment. Start the welding equipment and use the chuck to drive the pulsed laser welding auxiliary fixing seat to rotate. At the same time, use pulsed laser welding to weld the gap between the end ring and the pressing ring to form a circumferential weld, thereby forming a cylindrical filter.

[0015] Preferably, when performing resistance welding in Step 2 and Step 3, the welding current used is 310 A, and the duration is 2.8 ms.

[0016] Preferably, when performing pulsed laser welding in Step 4, the pulse frequency is 16 Hz, the rise time is 5 ms, the duration is 30 ms, the duty cycle is 19%, the positive defocus is 0.5, and the chuck rotation speed is 50 mm / s.

[0017] Preferably, the process of folding the sheet-shaped circular filter net into a cup-shaped filter net in Step 1 is as follows: First, tightly fit the middle of the sheet-shaped circular filter net with the end face of the net folding rod. Then, divide the sheet-shaped circular filter net into several equal parts, and fold it along the dividing lines from the edge of the sheet-shaped circular filter net to the edge of the end face of the net folding rod to form several pinched corners. Then, fit the several pinched corners clockwise or counterclockwise on the side wall of the net folding rod to form a cup-shaped filter net.

[0018] The beneficial effects of the present invention are as follows: 1. By using a net folding rod for manual net folding, the present invention can ensure the forming size and shape of the filter net, make the forming more accurate, avoid the damage phenomenon caused by the too thin filter net during the conventional forming process, and is more suitable for small-batch production. At the same time, it reduces the production cost. The cooperation of the net folding rod and the spot welding fixing seat is used to clamp the filter net and the pressing ring, which is convenient for the secondary forming of the filter net, makes the connection process between the filter net and the pressing ring more convenient to operate, limits the forming depth of the filter net, improves the dimensional accuracy of the final product, and provides a more convenient operation space for the spot welding between the pressing ring and the filter net. And in the process, the filter net and the pressing ring are first spot welded and fixed, which is convenient for the subsequent connection, clamping, and welding processes with the end ring, and the process is more optimized, and the forming and welding effect is better.

[0019] 2: The cooperation between the positioning tooling base and the positioning tooling can clamp and fix the filter screen, pressing ring, and end ring, and can apply pressure to the pressing ring and end ring to make them fit more closely with the filter screen. A spot welding window is opened on the positioning tooling base to fix and weld between the end ring and the pressing ring by resistance welding, achieving spot welding positioning and fixation, so as to provide an accurate welding position and clamping conditions for the subsequent circular welding process of pulsed laser welding.

[0020] 3: By setting a clamping groove on the laser pulse welding auxiliary fixing seat, the cylindrical filter can be clamped and fixed. The shrinkage clamping middle seam can give the shrinkage space of the laser pulse welding auxiliary fixing seat, making it clamp the end ring part of the cylindrical filter more tightly when clamped on the welding equipment chuck, and the clamping reliability is higher. When using the welding equipment chuck to clamp the laser pulse welding auxiliary fixing seat and performing pulsed laser welding, the welding torch does not move, and the chuck rotates to make the cylindrical filter rotate for welding, thus forming a circular weld between the pressing ring and the end ring, with higher welding quality and stronger welding stability.

[0021] 4: The forming welding method of the present invention has a more reasonable process. Using this method, the manufactured cylindrical filter can be made lighter while meeting the welding quality requirements and filtration needs. At the same time, in this method, the mesh folding is precise during the forming process, which can ensure that the filter screen after mesh folding has sufficient filter area and reduce the flow resistance; relying on the support of the forming welding structure of the present invention, the clamping process is more convenient and the clamping effect is better, and the best parameters for resistance spot welding and pulsed laser welding during the welding process of the thinner filter screen are given, with higher welding quality. This welding method has universality, typicality, innovation, representativeness and popularization and application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention, the drawings required for description in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0023] Figure 1 It is a schematic cross-sectional view of the connection relationship between the mesh folding rod and the spot welding fixing seat of the present invention;

[0024] Figure 2 It is a schematic three-dimensional view of the connection relationship between the mesh folding rod and the spot welding fixing seat of the present invention;

[0025] Figure 3 It is a schematic cross-sectional structure view of the cylindrical filter of the present invention;

[0026] Figure 4 It is a schematic structure view of the positioning tooling base of the present invention;

[0027] Figure 5 Schematic structural diagram of the positioning tooling for the present invention;

[0028] Figure 6 Schematic structural diagram of the connection between the female seat of the positioning tooling and the positioning tooling for the present invention;

[0029] Figure 7 Schematic cross-sectional diagram of the connection between the female seat of the positioning tooling and the positioning tooling for the present invention;

[0030] Figure 8 Schematic structural diagram of the auxiliary fixing seat for pulsed laser welding of the present invention;

[0031] Figure 9 Schematic diagram of the clamping relationship between the auxiliary fixing seat for pulsed laser welding and the cylindrical filter of the present invention;

[0032] Figure 10 Schematic diagram of the pinching angle position of the present invention;

[0033] Figure 11 Schematic structural diagram of the finished product after pinching the angle of the present invention. Specific embodiments

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0035] As Figures 1 - 3 shown in FIGS. 6, 7, and 8, in Embodiment 1, a forming and welding tooling for a cylindrical filter includes a folding net pressing ring spot welding module, an end ring spot welding and fixing module, and an auxiliary fixing seat 10 for pulsed laser welding, which are applicable to four main processing procedures in the forming and welding process. The cylindrical filter includes a filter net 1, an end ring 2, and a pressing ring 3, and the end ring 1 and the pressing ring 3 are respectively fixed on both sides of the filter net 1. The cylindrical filter used in this solution has a higher degree of lightweight, lower flow resistance, and a more solid structure compared to the original filter.

[0036] Among them, the folding net module includes a folding net rod 4 and a spot welding fixing seat 5. There is a groove 6 on the spot welding fixing seat 5. The folding net rod 4 is inserted and matched with the groove 6, and there is a gap between the outer side wall of the folding net rod 4 and the inner side wall of the groove 6. Setting the gap can ensure that the folding net rod can be smoothly inserted when carrying the filter net and inserting it into the groove. By using the folding net rod for manual folding of the net, the forming size and shape of the filter net can be guaranteed, the forming is more accurate, the phenomenon of damage caused by the too thin filter net during the conventional forming process can be avoided, and it is more suitable for small-batch production. At the same time, the production cost is reduced. The cooperation of the folding net rod and the spot welding fixing seat is used to clamp the filter net and the pressing ring, which is convenient for secondary forming of the filter net, makes the connection process of the filter net and the pressing ring more convenient to operate, limits the forming depth of the filter net, improves the dimensional accuracy of the final product, and provides a more convenient operation space for spot welding between the pressing ring and the filter net. And in the process, the filter net and the pressing ring are first spot welded and fixed, which is convenient for the subsequent connection, clamping, and welding processes with the end ring.

[0037] Among them, the end ring spot welding fixing module includes a positioning tooling female seat 7 and a positioning tooling 8. There are several spot welding windows 9 on the positioning tooling female seat 7. There is a circular opening cavity inside the positioning tooling female seat 7. The spot welding windows 9 are communicated with the circular opening cavity. The positioning tooling 8 is threadedly connected to the opening of the circular opening cavity. The end of the positioning tooling 8 and the inner bottom surface of the circular opening cavity jointly clamp and press the filter net 1, the end ring 2, and the pressing ring 3.

[0038] Among them, the pulsed laser welding auxiliary fixing seat 10 has a shrinkage clamping middle seam 11. One end of the pulsed laser welding auxiliary fixing seat 10 is provided with a clamping groove 12. The clamping groove 12 is matched with the size of the end ring 2. During use, the clamping groove 12 is used to clamp and fix the end ring to achieve the purpose of clamping the semi-finished tubular filter. The welding equipment in this embodiment is preferably a laser pulse welding equipment with a chuck, and the chuck can rotate. By setting the clamping groove on the pulsed laser welding auxiliary fixing seat, the tubular filter can be clamped and fixed. The shrinkage clamping middle seam can give the shrinkage space of the pulsed laser welding auxiliary fixing seat, so that when it is clamped on the chuck of the welding equipment, the end ring part of the tubular filter is clamped tighter and the clamping reliability is higher. And the pulsed laser welding auxiliary fixing seat is clamped by the chuck of the welding equipment. When performing pulsed laser welding, the welding torch does not move, and the tubular filter rotates for welding by using the rotation of the chuck. The welding quality is higher and the welding stability is stronger.

[0039] Such as Figure 3As shown in the figure, in Embodiment 2, on the basis of Embodiment 1, the filter net 1 is a cup-shaped filter net. An outer eaves 13 is provided on the outer side of the opening of the cup-shaped filter net. The outer eaves 13 and the pressing ring 3 are respectively arranged on both sides of the outer eaves 13. The end ring 2 is a two-stage stepped ring. The outer ring surface of the first-stage stepped ring with a smaller diameter is connected to the inner side wall of the cup-shaped filter net and corresponds to the inner ring surface of the pressing ring. The side wall of the first-stage stepped ring with a larger diameter is connected to the outer eaves 13. The structures of the pressing ring and the end ring in this embodiment are lighter, and at the same time, the volume is smaller than that of the cylindrical filter in the prior art under the condition of similar filtering effects, meeting the lightweight requirements.

[0040] Embodiment 3, on the basis of Embodiment 2, the folding net rod 4 is a two-stage stepped shaft, and the thicker first-stage stepped shaft is convenient to hold during operation. The thinner first-stage stepped shaft in the two-stage stepped shaft is inserted and matched with the groove 6. The spot welding fixing seat 5 is a frustum-shaped seat body. The groove 6 is opened in the middle of the frustum-shaped seat body. A clamping groove 14 corresponding to the pressing ring 3 is provided at the opening of the groove 6. The depth of the clamping groove is less than or equal to half of the thickness of the pressing ring, which not only meets the clamping of the pressing ring but also provides an operating space for the subsequent folding and welding processes of the filter net.

[0041] As Figures 4 - 7 As shown in the figure, in Embodiment 4, on the basis of Embodiment 3, one end of the positioning tooling female seat 7 is provided with a connecting hole 18 communicating with a circular opening cavity. The connecting hole 18 is located at the center of the inner bottom surface of the circular opening cavity. By setting the connecting hole, a rod-shaped object can be used to remove the semi-finished cylindrical filter from the positioning tooling female seat after spot welding is completed. The spot welding window 9 is flush with the inner bottom surface of the circular opening cavity. During clamping, one end of the end ring 2 first enters the circular opening cavity and contacts the inner bottom surface of the circular opening cavity. The spot welding window corresponds to the gap between the end ring and the pressing ring 3 for subsequent spot welding operations. The positioning tooling 8 includes a positioning seat 15. A positioning hole 16 is opened at one end of the positioning seat 15. The inner diameter of the positioning hole is larger than the outer diameter of the cup-shaped filter net. The outer side wall of the positioning seat 15 is threadedly connected to the inner wall of the circular opening cavity. Clamping planes 17 are provided on the outer side walls of both the positioning seat 15 and the positioning tooling female seat 7. The setting of the clamping plane facilitates applying force when rotating the positioning seat 15, so that its end abuts against the end face of the pressing ring, and as it is screwed in, the pressing ring, the outer eaves, and the end ring are pressed tightly. And the setting of the clamping plane can use a bench vice or the like for clamping during spot welding, facilitating the welding process.

[0042] The spot welding window 9 is a long strip-shaped waist hole and at least two are provided. In this embodiment, it is preferably set to four. The four long strip-shaped waist holes are arranged at equal intervals along the circumferential direction on the positioning tooling female seat 7. During spot welding, the welding head of the resistance welding passes through the long strip-shaped waist hole to perform spot welding and fixation between the pressing ring and the end ring.

[0043] Example 5. On the basis of Example 4, the pulsed laser welding auxiliary fixing seat 10 is an annular seat body. The shrinkage clamping middle seam 11 penetrates through the side wall of the annular seat body along the length direction, and a C-shaped retaining ring 19 is arranged in the middle of the annular seat body. The setting of the C-shaped retaining ring can limit the position during clamping and restrict the clamping length of the chuck. The C-shaped retaining ring 19 divides the annular seat body into a clamping part 20 and a clamping part 21. The clamping groove 12 is located at the end face of the clamping part 21. The diameter of the clamping part 20 is smaller than that of the clamping part 21, and the wall thickness of the clamping part 20 is less than or equal to that of the clamping part 21, which can make the clamping part more elastic and easier to shrink and change with clamping. At the same time, when the shrinkage force is transmitted from the clamping part to the clamping part, the force transmission is more balanced and has a certain elastic margin to prevent hard clamping from damaging the end ring. During clamping, first install the clamping part 20 on the chuck, hold the semi-finished product of the cylindrical filter by hand and set the end ring on it on the clamping groove 12, and at the same time clamp the chuck. The clamping jaws of the chuck apply pressure to the clamping part to make the shrinkage clamping middle seam 11 shrink, so that its diameter decreases, and the diameter of the clamping part also decreases accordingly, so as to clamp the end ring tighter.

[0044] Example 6. On the basis of Examples 1 to 5, a welding method using the above-mentioned cylindrical filter forming and welding tooling includes the following steps:

[0045] Step 1: Lay the sheet-shaped circular filter screen flat on the end face of the folding rod 4, and fold the sheet-shaped circular filter screen along the folding rod 4 into a cup-shaped filter screen. As Figure 10 、 11 shown, the process of folding the sheet-shaped circular filter screen into a cup-shaped filter screen is as follows: First, tightly fit the middle of the sheet-shaped circular filter screen with the end face of the folding rod 4, and then divide the sheet-shaped circular filter screen into four equal parts and pinch the corners from the edge of the sheet-shaped circular filter screen to the edge of the end face of the folding rod 4. The pinching positions are as Figure 10 shown in the figure, and then fit the four pinched corner parts clockwise or counterclockwise on the side wall of the folding rod 4 to form a cup-shaped filter screen as Figure 11 shown in the figure.

[0046] Then, set the pressing ring 3 on the clamping groove 14 on the spot welding fixing seat 5 for clamping and fixing, insert the folding rod 4 carrying the cup-shaped filter screen into the pressing ring 3 and into the groove 6 until the cup-shaped filter screen is in close contact with the bottom of the groove 6.

[0047] Step 2: Use tweezers to turn outwards the part of the cup-shaped filter screen that exceeds the pressing ring 3. The folding line is the dotted line indicated by A in Figure 11 shown in the figure, so that it fits with the end face of the pressing ring 3 to form an outer eaves 13, and the outer eaves 13 and the end face of the pressing ring 3 are fixed by resistance welding. When performing resistance welding, the welding current used is 310 A and the duration is 2.8 ms. After the welding and fixing are completed, trim the part of the outer eaves 13 that exceeds the pressing ring 3. The trimming area is as Figure 1 shown in the figure.

[0048] Step 3: Insert and fit the end ring 2 with the cup-shaped filter net so that the outer eaves 13 are located between the end ring 2 and the pressing ring 3 to form a semi-finished tubular filter. During the insertion, the outer ring surface of the thinner first-step ring of the end ring is closely attached to the inner ring surface of the cup-shaped filter net. At the same time, the outer ring surface of the thinner first-step ring of the end ring and the inner ring surface of the pressing ring jointly clamp the cup-shaped filter net tightly. That is, in the semi-finished tubular filter, the end face of the end ring and the end face of the pressing ring clamp the outer eaves 13, and the outer ring surface of the end ring and the inner ring surface of the pressing ring clamp the cup-shaped filter net, making the connection structure tighter and the quality of the tubular filter better. Then install the semi-finished tubular filter in the circular opening cavity inside the positioning tooling female seat 7, and make the outer eaves 13 correspond to the spot welding window 9. Thread the positioning tooling 8 into the opening of the circular opening cavity, and use the end face of the positioning tooling 8 and the inner bottom surface of the circular opening cavity to press and hold the end ring 2, the outer eaves 13, and the pressing ring 3 tightly. Then perform spot welding between the end ring 2 and the pressing ring 3 from the spot welding window 9 using resistance welding, where the resistance welding parameters are the same as those in Step 2.

[0049] Step 4: Clamp the semi-finished tubular filter after spot welding on the pulsed laser welding auxiliary fixing seat 10. Subsequently, clamp the pulsed laser welding auxiliary fixing seat 10 on the chuck of the welding equipment. Turn on the welding equipment to drive the pulsed laser welding auxiliary fixing seat 10 to rotate by the chuck. At the same time, use pulsed laser welding to weld the gap between the end ring 2 and the pressing ring 3 to form a circumferential weld, tightly welding the end ring, the outer eaves 13, and the pressing ring together to form a tubular filter. During pulsed laser welding, the pulse frequency is 16 Hz, the rise time is 5 ms, the duration is 30 ms, the duty cycle is 19%, the positive defocus is 0.5, and the chuck rotation speed is 50 mm / s. The pulsed laser welding forming effect is better under these parameters, and it can avoid phenomena such as burn-through and insecure welding.

[0050] The forming and welding method of the present invention has a more reasonable process. Using this method, the manufactured tubular filter can be made lighter while meeting the welding quality requirements and filtration needs. At the same time, in this method, the mesh folding during the forming process is precise, which can ensure that the filter net after mesh folding has sufficient filter net area and reduces the flow resistance. Relying on the support of the forming and welding structure of the present invention, the clamping process is more convenient and the clamping effect is better. The optimal parameters for resistance spot welding and pulsed laser welding during the welding process of the thinner filter net are given, and the welding quality is higher. This welding method has universality, typicality, innovation, representativeness, and promotion and application value.

[0051] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A cylindrical filter forming and welding tooling, characterized in that: It includes a folding net pressing ring spot welding module, an end ring spot welding and fixing module, and a pulsed laser welding auxiliary fixing seat (10) for forming and welding a cylindrical filter; The folding net pressing ring spot welding module includes a folding net rod (4) and a spot welding fixing seat (5). The spot welding fixing seat (5) is provided with a groove (6). The folding net rod (4) is inserted and matched with the groove (6), and there is a gap between the outer side wall of the folding net rod (4) and the inner side wall of the groove (6). The folding net rod (4) is a two-stage stepped shaft, and the thinner one of the two-stage stepped shafts is inserted and matched with the groove (6). The spot welding fixing seat (5) is a frustum-shaped seat body, and the groove (6) is opened in the middle of the frustum-shaped seat body. A clamping groove (14) corresponding to the pressing ring (3) is provided at the opening of the groove (6); The end ring spot welding and fixing module includes a positioning tooling female seat (7) and a positioning tooling (8). The positioning tooling female seat (7) is provided with a plurality of spot welding windows (9). The positioning tooling female seat (7) internally has a circular opening cavity, and the spot welding windows (9) communicate with the circular opening cavity. The positioning tooling (8) is threadedly connected to the opening of the circular opening cavity. The end of the positioning tooling (8) and the inner bottom surface of the circular opening cavity jointly clamp and press the cylindrical filter. One end of the positioning tooling female seat (7) is provided with a connection hole (18) communicating with the circular opening cavity. The connection hole (18) is located at the center of the inner bottom surface of the circular opening cavity, and the spot welding windows (9) are flush with the inner bottom surface of the circular opening cavity. The positioning tooling (8) includes a positioning seat (15). One end of the positioning seat (15) is provided with a positioning hole (16). The inner diameter of the positioning hole (16) is larger than the outer diameter of the cup-shaped filter net. The outer side wall of the positioning seat (15) is threadedly connected to the inner wall of the circular opening cavity. Clamping planes (17) are provided on the outer side walls of the positioning seat (15) and the positioning tooling female seat (7); The pulsed laser welding auxiliary fixing seat (10) has a shrinkage clamping middle seam (11). One end of the pulsed laser welding auxiliary fixing seat (10) is provided with a clamping groove (12), and the clamping groove (12) matches the size of the cylindrical filter. The pulsed laser welding auxiliary fixing seat (10) is an annular seat body. The shrinkage clamping middle seam (11) runs through the side wall of the annular seat body along the length direction. A C-shaped retaining ring (19) is provided in the middle of the annular seat body. The C-shaped retaining ring (19) divides the annular seat body into a clamping part (20) and a clamping part (21). The clamping groove (12) is located at the end face of the clamping part (21). The diameter of the clamping part (20) is smaller than that of the clamping part (21), and the wall thickness of the clamping part (20) is less than or equal to the wall thickness of the clamping part (21).

2. The cylindrical filter forming and welding tooling according to claim 1, characterized in that: The cylindrical filter includes a filter net (1), an end ring (2), and a pressing ring (3). The end ring (2) and the pressing ring (3) are respectively fixed on both sides of the filter net (1). The filter net (1) is a cup-shaped filter net. An outer eaves (13) is provided on the outer side of the opening of the cup-shaped filter net. The outer eaves (13) and the pressing ring (3) are respectively provided on both sides of the outer eaves (13). The end ring (2) is a two-stage stepped ring. The outer ring surface of the first-stage stepped ring with a smaller diameter is connected to the inner side wall of the cup-shaped filter net, and the side wall of the first-stage stepped ring with a larger diameter is connected to the outer eaves (13).

3. The cylindrical filter forming and welding tooling according to claim 2, characterized in that: The spot welding windows (9) are long strip-shaped waist holes and at least two are provided, and a plurality of long strip-shaped waist holes are arranged at equal intervals in the circumferential direction on the positioning tooling female seat (7).

4. A welding method using the cylindrical filter forming and welding tooling according to any one of claims 1 to 3, comprising the following steps: Step 1: Lay the sheet-shaped circular filter screen flat on the end face of the net folding rod (4), fold the sheet-shaped circular filter screen along the net folding rod (4) into a cup-shaped filter screen, then place the pressing ring (3) on the spot welding fixing seat (5), insert the net folding rod (4) carrying the cup-shaped filter screen into the pressing ring (3) and into the groove (6) until the cup-shaped filter screen is in close contact with the bottom of the groove (6); Step 2: Use tweezers to turn outwards the part of the cup-shaped filter screen that exceeds the pressing ring (3) so that it fits against the end face of the pressing ring (3) to form an outer eaves (13), and perform resistance welding fixation on the outer eaves (13) and the end face of the pressing ring (3). After the welding fixation is completed, trim the part of the outer eaves (13) that exceeds the side wall of the pressing ring (3); Step 3: Insert the end ring (2) into the cup-shaped filter screen in a mating manner so that the outer eaves (13) is located between the end ring (2) and the pressing ring (3) to form a semi-finished cylindrical filter, then install the semi-finished cylindrical filter in the circular opening cavity inside the positioning tooling female seat (7), and make the outer eaves (13) correspond to the spot welding windows (9). Screw the positioning tooling (8) into the opening of the circular opening cavity in a threaded manner, and use the end face of the positioning tooling (8) and the inner bottom surface of the circular opening cavity to press the end ring (2), the outer eaves (13), and the pressing ring (3) tightly, and then perform spot welding between the end ring (2) and the pressing ring (3) from the spot welding windows (9) using resistance welding; Step 4: Clamp the semi-finished cylindrical filter after spot welding on the pulsed laser welding auxiliary fixing seat (10), then clamp the pulsed laser welding auxiliary fixing seat (10) on the chuck of the welding equipment. Start the welding equipment to drive the pulsed laser welding auxiliary fixing seat (10) to rotate by the chuck, and at the same time use pulsed laser welding to weld the gap between the end ring (2) and the pressing ring (3) to form a circumferential weld, thereby forming a cylindrical filter.

5. The welding method according to claim 4, wherein: When performing resistance welding in Step 2 and Step 3, the welding current used is 310A and the duration is 2.8ms.

6. The welding method according to claim 5, characterized in that: When performing pulsed laser welding in Step 4, the pulse frequency is 16Hz, the rise time is 5ms, the duration is 30ms, the duty cycle is 19%, the positive defocus is 0.5, and the chuck rotation speed is 50mm / s.

7. The welding method according to claim 6, characterized in that: The process of folding the sheet-shaped circular filter screen into a cup-shaped filter screen in Step 1 is as follows: First, tightly fit the middle part of the sheet-shaped circular filter screen against the end face of the net folding rod (4), then divide the sheet-shaped circular filter screen into several equal parts, and fold along the dividing lines from the edge of the sheet-shaped circular filter screen to the edge of the end face of the net folding rod (4) to form several pinched corners, and then fit the several pinched corners against the side wall of the net folding rod (4) clockwise or counterclockwise to form a cup-shaped filter screen.

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