Fixture structure and method for laser penetration welding of box guide rails

Abstract

The present invention provides a fixture structure and method for laser penetration welding of box guide rails. The fixture structure for laser penetration welding of box guide rails includes a guide rail internal expansion support positioning device; the guide rail internal expansion support positioning device is used to tightly fit the box skin and the guide rail; the guide rail internal expansion support positioning device includes a driving assembly, a box rotation assembly, a rotating shaft cylinder, an internal expansion pull rod and one or more support positioning assemblies; the rotating shaft cylinder is sleeved on the outside of the internal expansion pull rod, and a single support positioning assembly includes multiple groups of wedge-shaped sliding pairs distributed along the axial direction of the internal expansion pull rod and multiple guide rail positioning blocks distributed along the axial direction of the rotating shaft cylinder; the present invention effectively avoids the shortcomings of low production efficiency and low installation accuracy of traditional box guide rail stud welding and manual TIG welding of corner joints. It can realize the production of narrow box skins and guide rails.

Description

Technical Field

[0001] The present invention relates to the field of welding technology, and in particular to a fixture structure and method for laser penetration welding of a box guide rail. Background Art

[0002] The box guide rail assembly is mainly composed of box skin and guide rails. Each box is installed with 2 to 4 guide rails, and the box skin and the guide rails are connected by welding or screwing. In the traditional manufacturing process, the guide rails are usually fixed by manual welding of the corner joints between the skin and the guide rails or by using studs to fix the internal guide rails after drilling holes in the box skin. The production efficiency is low and the guide rail installation accuracy is not high. With the miniaturization of the projectile structure, the internal space of the box skin is extremely limited. The traditional manual welding method or stud welding is gradually unable to adapt to the large-scale, high-precision and high-efficiency production requirements of the box assembly.

[0003] Laser welding technology has the advantages of strong penetration ability and high welding efficiency. With the popularization and application of high-power lasers, it has become possible to connect the box skin and guide rails through laser penetration welding.

[0004] Since the assembly precision of the box rail laser welding is extremely high, and the narrow internal space of the box skin brings great difficulties to the welding and assembly of the box skin, the accurate and stable fixture structure is the key factor for the quality of the box rail laser welding.

[0005] Patent document CN106229431A discloses a guide rail for installing a battery pack box and an installation method thereof, and the method is as follows:

[0006] (1) The battery pack box is fixed in a snap-fit ​​manner between the battery pack box clamping edges of the box fixing mechanism;

[0007] (2) pre-installing and fixing the frame fixing mechanism on the frame by passing bolts through the frame fixing holes;

[0008] (3) Lift the battery pack box to the height of the frame fixed rail, and push the box to the desired installation position until the shape of the box matching the inclined surface and the track pressing inclined surface are pressed against each other;

[0009] (4) The battery pack box can be fixed to the frame by passing bolts through the fixing holes and fixing them in the fixing channels. However, this method still uses the above-mentioned method of using studs to fix the internal guide rails after punching holes, and still has low production efficiency and is not suitable for large-scale, high-precision, and high-efficiency production requirements. Summary of the invention

[0010] In view of the defects in the prior art, an object of the present invention is to provide a fixture structure and method for laser penetration welding of box guide rails.

[0011] According to the present invention, a fixture structure for laser penetration welding of a box rail includes a rail internal expansion support positioning device; the rail internal expansion support positioning device is used to closely fit the box skin and the rail;

[0012] The guide rail internal expansion support and positioning device comprises a driving assembly, a box rotating assembly, a rotary shaft cylinder, an internal expansion pull rod and one or more groups of support and positioning assemblies;

[0013] The rotary shaft cylinder is sleeved on the outside of the inner expansion rod, and the single support positioning assembly includes a plurality of wedge-shaped sliding pairs distributed along the axial direction of the inner expansion rod and a plurality of guide rail positioning blocks distributed along the axial direction of the rotary shaft cylinder;

[0014] The rotary shaft cylinder is provided with a plurality of limiting holes, the wedge-shaped sliding pair comprises a first wedge block and a second wedge block which match each other, a guide rail mounting position is provided inside the second wedge block; the first wedge block is fastened to the inner expansion rod, the second wedge block passes through the limiting hole and extends to the outside of the limiting hole; the second wedge block can move between a first position and a second position along the radial direction of the rotary shaft cylinder relative to the first wedge block; the guide rail positioning blocks and the wedge-shaped sliding pair are arranged alternately;

[0015] The driving assembly is connected to the inner expansion rod and is used to drive the inner expansion rod to reciprocate between the third position and the fourth position along the axial direction of the rotating shaft cylinder; the guide rail positioning block is used to limit the movement of the guide rail along the axial direction of the rotating shaft cylinder;

[0016] The first wedge block can convert the reciprocating movement of the inner expansion rod along the axial direction of the rotating shaft cylinder into the reciprocating movement of the second wedge block along the radial direction of the rotating shaft cylinder;

[0017] The first position is the lowest point of the radial movement of the second wedge block along the rotating shaft cylinder, and the second position is the highest point of the radial movement of the second wedge block along the rotating shaft cylinder; the third position is one end point of the reciprocating motion of the inner expansion rod, and the fourth position is the other end point of the reciprocating motion of the inner expansion rod;

[0018] The guide rail internal expansion support and positioning device has a supporting state and a relaxed state; when the guide rail internal expansion support and positioning device is in the relaxed state, the second wedge block is located at the first position, the internal expansion pull rod is located at the third position, and the box skin is not tightly fitted to the guide rail; when the guide rail internal expansion support and positioning device is in the supporting state, the second wedge block is located at the second position, the internal expansion pull rod is located at the fourth position, and the second wedge block tightly fits the box skin to the guide rail;

[0019] The box rotating assembly is used to drive the rotary shaft cylinder and the inner expansion rod to rotate along their own axis.

[0020] Preferably, the drive assembly is a hydraulic drive assembly, including a cylinder connecting shaft and a hydraulic cylinder, one end of the cylinder connecting shaft is interconnected with the hydraulic cylinder, and the other end of the cylinder connecting shaft is connected to one end of the internal expansion rod.

[0021] Preferably, the box rotating assembly includes a rotating drive gear pair and a rotating drive motor, the rotating drive gear pair is drivingly connected to the rotating drive motor, and the rotating drive gear pair is also drivingly connected to the rotating shaft cylinder and the inner expansion rod.

[0022] Preferably, it also includes a fixed head seat, the guide rail inward expansion support and positioning device is installed on the fixed head seat, and the fixed head seat includes a head seat body, reinforcement ribs, a base plate and fasteners; the guide rail inward expansion support and positioning device is installed on the head seat body, the head seat body and the base plate are connected through the reinforcement ribs, and the fasteners are used to fix the base plate to the installation ground.

[0023] Preferably, it also includes a tailstock, which includes a tailstock main box and a hydraulic cylinder, a cylinder joint, a cylinder push rod, a tailstock support rod, and a roller bearing pair connected in sequence; the hydraulic cylinder can drive the cylinder push rod to drive the tailstock support rod to make the roller bearing pair perform lifting movement, and a first supporting surface is provided on the roller bearing pair, and the first supporting surface contacts with the end of the guide rail inward expansion support positioning device to provide support for the guide rail inward expansion support positioning device.

[0024] Preferably, the number of the supporting and positioning components is 4, and the 4 supporting and positioning components are evenly distributed along the circumference of the rotating shaft cylinder.

[0025] According to a method for laser penetration welding of a box guide rail provided by the present invention, the fixture structure for laser penetration welding of the box guide rail is adopted, and the method further comprises the following steps:

[0026] S11: Clean the oil stains on the surface of the box skin to be welded and multiple guide rails.

[0027] S12: installing a plurality of guide rails on the guide rail inner expansion support positioning device respectively, inserting the box skin to be welded from the tail of the inner support device, rotating the box skin to adjust the relative position of the box skin and the guide rail; and supporting the tailstock at the end of the guide rail inner expansion support positioning device;

[0028] S13: starting the guide rail internal expansion support positioning device, adjusting the guide rail internal expansion support positioning device to a supporting state, and completing radial support of the guide rail;

[0029] S14: Check the gap between the box skin and the guide rail to ensure that the gap △t is no greater than 10% of the box skin thickness δ;

[0030] S15: Use the box rotating assembly to rotate the rotary shaft cylinder to rotate the to-be-welded surface of the box skin and the guide rail to a horizontal upward state;

[0031] S16: setting laser welding parameters, the laser heat source is vertically set into the outer surface of the box skin, penetrates the box skin and melts the guide rail closely attached to the skin to form a connecting weld;

[0032] S17: Use laser wire welding or laser arc hybrid welding to weld the box skin and guide rails.

[0033] Preferably, in step S17, the welding parameters are: laser output power 4kW to 10kW, welding speed 1m / min, welding gas flow 10L / min to 25L / min, laser defocus -5mm to +5mm.

[0034] Preferably, in step S17, a paraxial laser-MIG composite welding method is adopted, with a laser output power of 5500 W, a welding speed of 3 m / min, a welding gas flow rate of 20 L / min, a laser defocus amount of +5 mm, a welding current of 105 A, a current output mode of non-pulsed DC, and an arc length correction of 0.

[0035] Preferably, step S12 specifically includes:

[0036] S121: After the guide rail and the box skin are installed on the guide rail internal expansion support positioning device, the second hydraulic cylinder 41 of the support tailstock is started to prop up the tail end of the guide rail internal expansion support positioning device, and the stroke of the support tailstock support rod is adjusted to ensure that the coaxiality of the head and tail of the box is not greater than 0.2mm;

[0037] S122: Adjust the relative position of the box skin and the guide rail to ensure that the installation position of the box skin and the guide rail meets the requirements of the parts drawing.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] 1. The laser penetration welding fixture and welding method for box rails provided by the present invention effectively avoid the shortcomings of low production efficiency and low installation accuracy of traditional box rail stud welding and manual TIG welding of corner joints. It can realize the production of narrow box skins and rails.

[0040] 2. The present invention can realize one-stop positioning, assembly and welding of the box skin and the guide rail. Through the design of the guide rail positioning block and the laser welding process, the deformation of the box guide rail during the welding process can be reduced.

[0041] 3. The present invention simplifies the forming process of the box guide rail assembly parts in the prior art, which helps to achieve large-scale and efficient production of the box skin. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0043] Figure 1 It is a structural schematic diagram of the guide rail internal expansion support positioning device of the present invention;

[0044] Figure 2 It is a structural schematic diagram of the guide rail internal expansion support and positioning device of the present invention in a supporting state;

[0045] Figure 3 It is a structural schematic diagram of the fixed head seat of the present invention;

[0046] Figure 4 for Figure 3 The structural diagram on the back;

[0047] Figure 5 It is a structural schematic diagram of the tailstock of the present invention;

[0048] The figure shows:

[0049]

[0050] DETAILED DESCRIPTION

[0051] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0052] The present invention provides a fixture structure for laser penetration welding of a box guide rail, such as Figure 1 As shown, it includes a guide rail internal expansion support positioning device 1; the guide rail internal expansion support positioning device 1 is used to tightly fit the box skin 22 with the guide rail 21;

[0053] The guide rail internal expansion support and positioning device 1 includes a driving component 5, a box rotation component 6, a rotating shaft cylinder 17, an internal expansion rod 11 and one or more support and positioning components 10; in a preferred example, the rotating shaft cylinder 17 and the internal expansion rod 11 are made of cast iron, because cast iron is not easy to deform, can ensure that the deflection of the parts after assembly is small, and has low cost and easy processing. Specifically, the deflection of the rotating shaft cylinder 17 and the internal expansion rod 11 is less than 10mm.

[0054] In a preferred example, the rotary shaft cylinder 17 is a cylindrical structure. The rotary shaft cylinder 17 is sleeved on the outside of the inner expansion rod 11, and the single support positioning assembly 10 includes multiple groups of wedge-shaped sliding pairs 14 distributed along the axial direction of the inner expansion rod 11 and multiple guide rail positioning blocks 16 distributed along the axial direction of the rotary shaft cylinder 17; preferably, the distribution of the wedge-shaped sliding pairs 14 in the axial length should ensure that the guide rail is uniformly stressed, and specifically, the spacing between different wedge-shaped sliding pairs 14 is 400mm to 1000mm.

[0055] The rotating shaft cylinder 17 is provided with a plurality of limiting holes 15, and the wedge-shaped sliding pair 14 includes a first wedge block 141 and a second wedge block 142 that match each other. The second wedge block 142 is provided with a guide rail installation position. Preferably, the second wedge block 142 adopts a "concave" shape design, and the guide rail installation position is located in the "concave" shaped groove. The first wedge block 141 is tightly connected to the inner expansion rod 11, and the second wedge block 142 passes through the limiting hole 15 and extends to the outside of the limiting hole 15; the second wedge block 142 can move between the first position and the second position along the radial direction of the rotating shaft cylinder 17 relative to the first wedge block 141; the guide rail positioning block 16 and the wedge-shaped sliding pair 14 are arranged alternately; preferably, the radial stroke of the second wedge block 142 is 10mm to 50mm, and the guide rail positioning block 16 is provided within 100mm at both ends of the rotating shaft cylinder 17.

[0056] The driving assembly 5 is connected to the internal expansion rod 11, and is used to drive the internal expansion rod 11 to reciprocate between the third position and the fourth position along the axial direction of the rotating shaft cylinder 17, that is, to realize the telescopic movement of the internal expansion rod 11 in the rotating shaft cylinder 17. The guide rail positioning block 16 is used to limit the axial movement of the guide rail 21 along the rotating shaft cylinder 17; the guide rail positioning block 16 is directly fixed on the rotating shaft cylinder 17 with bolts.

[0057] Since the second wedge block 142 is restricted by the upper limit hole 15 of the rotary shaft cylinder 17, when the first wedge block D moves with the inner expansion rod 11, the first wedge block 141 can convert the axial reciprocating movement of the inner expansion rod 11 along the rotary shaft cylinder 17 into the radial reciprocating movement of the second wedge block 142 along the rotary shaft cylinder 17;

[0058] The first position is the lowest point of the radial movement of the second wedge block 142 along the rotating shaft cylinder 17, and the second position is the highest point of the radial movement of the second wedge block 142 along the rotating shaft cylinder 17; the third position is one end point of the reciprocating movement of the inner expansion rod 11, and the fourth position is the other end point of the reciprocating movement of the inner expansion rod 11;

[0059] The guide rail internal expansion support and positioning device 1 has a supporting state and a relaxed state; when the guide rail internal expansion support and positioning device 1 is in the relaxed state, the second wedge block 142 is located in the first position, the internal expansion rod 11 is located in the third position, and the box skin 22 is not tightly fitted with the guide rail 21; Figure 2 As shown, when the guide rail internal expansion support and positioning device 1 is in the supporting state, the second wedge block 142 is located at the second position, the internal expansion tie rod 11 is located at the fourth position, and the second wedge block 142 tightly fits the box skin 22 with the guide rail 21. The guide rail internal expansion support and positioning device 1 moves the second wedge block 142 radially through the telescopic reciprocating motion of the internal expansion tie rod 11 to achieve the switching of the state of the guide rail internal expansion support and positioning device 1. The wedge-shaped sliding pair 14 can directly act on the guide rail 21 to provide radial external support force for the guide rail 21. It is worth noting that when the guide rail internal expansion support and positioning device 1 switches between the support state and the relaxation state, since the second wedge block 142 will move up and down, the depth of the guide rail positioning block 16 of the guide rail 21 in the same support and positioning assembly 10 where the second wedge block 142 is located will also change. However, the guide rail positioning block 16 is used to limit the axial movement of the guide rail 21 along the rotating shaft cylinder 17. Therefore, as long as the guide rail 21 is still located in the guide rail positioning block 16, the guide rail positioning block 16 can play its role.

[0060] The driving assembly 5 is used to provide driving force for the state switching of the guide rail internal expansion support positioning device 1. The driving assembly 5 is a hydraulic driving assembly, including a cylinder connecting shaft 12 and a first hydraulic cylinder 13, one end of the cylinder connecting shaft 12 is connected to the first hydraulic cylinder 13, and the other end of the cylinder connecting shaft 12 is connected to one end of the internal expansion rod 11. The internal expansion rod 11 is connected to the first hydraulic cylinder 13 through the cylinder connecting shaft 12, and is driven by the first hydraulic cylinder 13 to complete the telescopic reciprocating motion.

[0061] The box rotating assembly 6 is used to drive the rotating shaft cylinder 17 and the internal expansion rod 11 to rotate along their own axis. The box rotating assembly 6 includes a rotating drive gear pair 18 and a rotating drive motor 19. The rotating drive gear pair 18 is in transmission connection with the rotating drive motor 19. The rotating drive gear pair 18 is also in transmission connection with the rotating shaft cylinder 17 and the internal expansion rod 11. Specifically, the rotating drive motor 19 drives the rotating shaft cylinder 17 and the internal expansion rod 11 to rotate through the rotating drive gear pair 18, so that the to-be-welded surfaces of the box skin 22 and the guide rail 21 remain facing upward during the welding process. In a preferred example, as Figure 1 As shown, the box rotating assembly 6 is located on the rotating shaft cylinder 17 at one end close to the third position.

[0062] In a preferred embodiment, Figure 3 and Figure 4As shown, the fixture structure for laser penetration welding of the box rail also includes a fixed headstock 3, and the rail internal expansion support positioning device 1 is installed on the fixed headstock 3 in a cantilever beam manner. The rail internal expansion support positioning device 1 is installed on the fixed headstock 3, and the fixed headstock 3 includes a headstock body 31, a reinforcing rib 32, a bottom plate 34 and a fastener; the rail internal expansion support positioning device 1 is installed on the headstock body 31, and the headstock body 31 is connected to the bottom plate 34 through the reinforcing rib 32, and the fastener is used to fix the bottom plate 34 to the installation ground. Preferably, the fastener is a fixing bolt 33.

[0063] In a preferred embodiment, Figure 5 As shown, the fixture structure for laser penetration welding of the box rail also includes a tailstock 4, which includes a tailstock main box 46 and a second hydraulic cylinder 41, a cylinder joint 42, a cylinder push rod 43, a tailstock support rod 44, and a roller bearing pair 45 connected in sequence; the second hydraulic cylinder 41 can drive the cylinder push rod 43 to drive the tailstock support rod 44 to make the roller bearing pair 45 move up and down, and the roller bearing pair 45 is provided with a first supporting surface, which contacts the end of the guide rail internal expansion support positioning device 1 to provide support for the guide rail internal expansion support positioning device 1. In a preferred example, the tailstock 4 is fixed to the bottom surface of the workbench by bolts 47, and the coaxiality of the tailstock 4 and the fixed headstock 3 is not greater than 0.2mm.

[0064] The number of the support and positioning components 10 is set according to the number of guide rails in the skin of the box body, and generally, the principle of symmetry about the center axis or center plane of the box body is followed as much as possible. In a preferred example, the number of the support and positioning components 10 is 4, and the 4 support and positioning components 10 are evenly distributed along the circumference of the rotating shaft cylinder 17. In this preferred example, the guide rail 21 is an I-beam guide rail, and the number of the guide rails 21 is also 4, and the guide rail positioning block 16 adopts a "concave" shape design to ensure the precise distribution of multiple guide rails 21 in the circumferential direction, and the guide rail positioning block 16 will not limit the movement of the guide rail 21 in the radial direction of the box body.

[0065] According to a method for laser penetration welding of a box guide rail provided by the present invention, the fixture structure for laser penetration welding of the box guide rail is adopted, and the method further comprises the following steps:

[0066] S11: Clean the surface oil stains of the box skin 22 and the plurality of guide rails 21 to be welded.

[0067] S12: Install multiple guide rails 21 on the guide rail inner expansion support positioning device 1 respectively, insert the box skin 22 to be welded from the tail of the inner support device, and support the tail seat 4 at the end of the guide rail inner expansion support positioning device 1; rotate the box skin 22 to adjust the relative position of the box skin 22 and the guide rail 21, that is, determine the specific position of the guide rail 21 welded to the box skin 22;

[0068] S13: starting the guide rail internal expansion support positioning device 1, adjusting the guide rail internal expansion support positioning device 1 to a supporting state, completing radial support of the guide rail, that is, fitting the guide rail 21 with the skin 22;

[0069] S14: Check the fitting gap between the box skin and the guide rail to ensure that the fitting gap △t is not greater than 10% of the box skin thickness δ; preferably, δ=0, that is, the box skin and the guide rail are tightly fitted.

[0070] S15: Use the box rotating assembly 6 to rotate the rotary shaft cylinder 17 to rotate the to-be-welded surface of the box skin 22 and the guide rail 21 to a horizontal upward state;

[0071] S16: Setting laser welding parameters, the laser heat source is vertically set into the outer surface of the box skin, penetrates the box skin and melts the guide rails that are close to the skin to form a connecting weld. The welding direction is from one end of the box skin 22 to the other end, that is, the welding direction is along the axial direction of the rotating shaft cylinder 17.

[0072] S17: The box body skin 22 and the guide rail 21 are welded by a laser wire welding method or a laser arc hybrid welding method.

[0073] S18, after the welding of one guide rail 21 is completed, the laser welding head is removed, and steps S15 and S16 are repeated to continue welding other guide rails 21 until all guide rails 21 are welded.

[0074] S19, after the box guide rail is welded and cooled, cut off the pressure of the first hydraulic cylinder 13, loosen the internal support of the guide rail; cut off the pressure of the second hydraulic cylinder 41, lower the tailstock support, and remove the welded box guide rail from the tooling.

[0075] Wherein, the cleaning described in S11 is alcohol wiping.

[0076] Step S12 specifically includes:

[0077] S121: After the guide rail and the box skin 22 are installed on the guide rail internal expansion support positioning device 1, the second hydraulic cylinder 41 of the support tailstock is started to prop up the tail end of the guide rail internal expansion support positioning device 1, and the stroke of the support tailstock support rod is adjusted to ensure that the coaxiality of the head and tail of the box is not greater than 0.2mm;

[0078] S122: Adjust the relative position of the box skin and the guide rail to ensure that the installation position of the box skin and the guide rail meets the requirements of the parts drawing.

[0079] Step S13 specifically includes:

[0080] S131: Start the first hydraulic cylinder 13 of the fixed head seat to drive the inner expansion rod 11 to move axially along the box body to complete the radial support of the guide rail and ensure that the box body skin is completely fitted with the guide rail.

[0081] The welding process in step S16 can be intermittent welding, and the intermittent length ratio is determined by the welding process to ensure that the box skin and the guide rail are firmly combined. Specifically, step S16 includes:

[0082] S161: Mark the outer surface of the box skin in advance according to the parts drawing, move the laser welding head, and set the welding starting point and arc ending point according to the marking and process specifications.

[0083] S162: Set laser parameters and laser head motion parameters, set MIG welding parameters, and adjust the filament spacing.

[0084] S163: Start the laser and MIG welder, and the laser heat source enters the outer surface of the box skin vertically, penetrates the box skin and melts the guide rail that is tightly attached to the skin to form a connecting weld.

[0085] In step S17, the welding parameters are: laser output power 4kW to 10kW, welding speed 1m / min, welding gas flow 10L / min to 25L / min, laser defocus -5mm to +5mm, and welding gas is argon. Specifically, in step S17, a paraxial laser-MIG composite welding method is adopted, with a laser output power of 5500W, a welding speed of 3m / min, a welding gas flow of 20L / min, a laser defocus +5mm, a welding current of 105A, a current output mode of non-pulsed DC, and an arc length correction of 0; the laser beam has a transverse high-frequency oscillation function, an oscillation frequency of 200Hz, and a scanning width of 3mm.

[0086] In summary, the present invention can quickly realize the positioning and assembly of the box skin and the guide rails during welding, reduce the difficulty of assembling the box guide rails, and meet the high-precision and high-efficiency assembly requirements of the box guide rails. After the present invention utilizes the guide rail internal expansion support positioning device and welding method of the above-mentioned embodiment to weld, a weld is formed on the outer surface of the box skin, and the box skin and the guide rail are effectively connected by laser penetrating the weld. In addition, the present invention also reduces the shaping and correction process of the box skin, and reduces the precision requirements for the sheet metal welding of the box skin. And it makes full use of the advantages of laser deep penetration welding, and connects the box skin and the guide rail in the form of a T-shaped lap joint, which provides a basis for the efficient and high-quality production of the box assembly.

[0087] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0088] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A fixture structure for laser penetration welding of box rails, characterized in that: It comprises a guide rail internal expansion support positioning device (1); the guide rail internal expansion support positioning device (1) is used to tightly fit the box body skin (22) and the guide rail (21); The guide rail internal expansion support and positioning device (1) comprises a driving component (5), a box rotating component (6), a rotary shaft cylinder (17), an internal expansion pull rod (11) and one or more groups of support and positioning components (10); The rotary shaft cylinder (17) is sleeved on the outside of the inner expansion rod (11), and the single support positioning assembly (10) includes a plurality of wedge-shaped sliding pairs (14) distributed along the axial direction of the inner expansion rod (11) and a plurality of guide rail positioning blocks (16) distributed along the axial direction of the rotary shaft cylinder (17); The rotating shaft cylinder (17) is provided with a plurality of limiting holes (15); the wedge-shaped sliding pair (14) comprises a first wedge block (141) and a second wedge block (142) which match each other; a guide rail mounting position is provided inside the second wedge block (142); the first wedge block (141) is tightly connected to the inner expansion rod (11); the second wedge block (142) passes through the limiting hole (15) and extends to the outside of the limiting hole (15); the second wedge block (142) can move between a first position and a second position along the radial direction of the rotating shaft cylinder (17) relative to the first wedge block (141); the guide rail positioning block (16) and the wedge-shaped sliding pair (14) are arranged alternately; The driving assembly (5) is connected to the inner expansion rod (11) and is used to drive the inner expansion rod (11) to reciprocate between a third position and a fourth position along the axial direction of the rotating shaft cylinder (17); the guide rail positioning block (16) is used to limit the axial movement of the guide rail (21) along the rotating shaft cylinder (17); The first wedge block (141) is capable of converting the reciprocating movement of the inner expansion rod (11) along the axial direction of the rotating shaft cylinder (17) into the reciprocating movement of the second wedge block (142) along the radial direction of the rotating shaft cylinder (17); The first position is the lowest point of the radial movement of the second wedge block (142) along the rotating shaft cylinder (17), and the second position is the highest point of the radial movement of the second wedge block (142) along the rotating shaft cylinder (17); the third position is one end point of the reciprocating movement of the inner expansion rod (11), and the fourth position is the other end point of the reciprocating movement of the inner expansion rod (11); The guide rail internal expansion support and positioning device (1) has a supporting state and a relaxed state; when the guide rail internal expansion support and positioning device (1) is in the relaxed state, the second wedge block (142) is located at the first position, the internal expansion rod (11) is located at the third position, and the box skin (22) and the guide rail (21) are not tightly fitted; when the guide rail internal expansion support and positioning device (1) is in the supporting state, the second wedge block (142) is located at the second position, the internal expansion rod (11) is located at the fourth position, and the second wedge block (142) tightly fits the box skin (22) and the guide rail (21); The box rotating assembly (6) is used to drive the rotating shaft cylinder (17) and the inner expansion rod (11) to rotate along their own axis.

2. The fixture structure for laser penetration welding of box guide rails according to claim 1 is characterized in that: The drive assembly (5) is a hydraulic drive assembly, comprising a cylinder connecting shaft (12) and a first hydraulic cylinder (13), one end of the cylinder connecting shaft (12) being interconnected with the first hydraulic cylinder (13), and the other end of the cylinder connecting shaft (12) being connected with one end of the inner expansion rod (11).

3. The fixture structure for laser penetration welding of box guide rails according to claim 1 is characterized in that: The box rotating assembly (6) comprises a rotating drive gear pair (18) and a rotating drive motor (19), wherein the rotating drive gear pair (18) is transmission-connected to the rotating drive motor (19), and the rotating drive gear pair (18) is also transmission-connected to the rotating shaft cylinder (17) and the inner expansion rod (11).

4. The fixture structure for laser penetration welding of box guide rails according to claim 1 is characterized in that: It also includes a fixed head seat (3), the guide rail internal expansion support positioning device (1) is installed on the fixed head seat (3), and the fixed head seat (3) includes a head seat body (31), reinforcing ribs (32), a base plate (34) and fasteners; the guide rail internal expansion support positioning device (1) is installed on the head seat body (31), the head seat body (31) and the base plate (34) are connected via the reinforcing ribs (32), and the fasteners are used to fix the base plate (34) to the installation ground.

5. The fixture structure for laser penetration welding of box guide rails according to claim 1, characterized in that: The invention also comprises a tailstock (4), wherein the tailstock (4) comprises a tailstock main box (46) and a second hydraulic cylinder (41), a cylinder joint (42), a cylinder push rod (43), a tailstock support rod (44), and a roller bearing pair (45) connected in sequence; the second hydraulic cylinder (41) can drive the cylinder push rod (43) to drive the tailstock support rod (44) to make the roller bearing pair (45) perform lifting movement, and a first supporting surface is provided on the roller bearing pair (45), and the first supporting surface contacts the end of the guide rail internal expansion support positioning device (1) to provide support for the guide rail internal expansion support positioning device (1).

6. The fixture structure for laser penetration welding of box rails according to claim 1, characterized in that: The number of the supporting and positioning components (10) is four, and the four supporting and positioning components (10) are evenly distributed along the circumference of the rotating shaft cylinder (17).

7. A laser penetration welding method for a box rail, characterized in that: The fixture structure for laser penetration welding of the box guide rail according to any one of claims 1 to 6 further comprises the following steps: S11: Cleaning the surface oil stains of the box skin (22) to be welded and the plurality of guide rails (21); S12: installing a plurality of guide rails (21) respectively onto the guide rail internal expansion support positioning device (1), inserting the box skin (22) to be welded from the rear end of the internal support device, rotating the box skin (22) to adjust the relative position of the box skin (22) and the guide rail (21); and supporting the tailstock (4) at the end of the guide rail internal expansion support positioning device (1); S13: starting the guide rail internal expansion support positioning device (1), adjusting the guide rail internal expansion support positioning device (1) to a supporting state, and completing radial support of the guide rail; S14: Check the gap between the box skin and the guide rail to ensure that the gap △t is no greater than 10% of the box skin thickness δ; S15: Using the box rotating assembly (6) to rotate the rotating shaft cylinder (17), the to-be-welded surfaces of the box skin (22) and the guide rail (21) are rotated to a horizontal upward state; S16: setting laser welding parameters, the laser heat source is vertically set into the outer surface of the box skin, penetrates the box skin and melts the guide rail closely attached to the skin to form a connecting weld; S17: Using a laser wire-filling welding method or a laser arc hybrid welding method to weld the box body skin (22) and the guide rail (21).

8. The laser penetration welding method for box guide rails according to claim 7, characterized in that: In step S17, the welding parameters are: laser output power 4kW to 10kW, welding speed 1m / min, welding gas flow 10L / min to 25L / min, laser defocus -5mm to +5mm.

9. The laser penetration welding method for box guide rails according to claim 7, characterized in that: In step S17, a paraxial laser-MIG composite welding method is adopted, with a laser output power of 5500 W, a welding speed of 3 m / min, a welding gas flow rate of 20 L / min, a laser defocus amount of +5 mm, a welding current of 105 A, a current output mode of non-pulsed DC, and an arc length correction of 0.

10. The laser penetration welding method for box rails according to claim 7, characterized in that: Step S12 specifically includes: S121: After the guide rail and the box skin (22) are installed on the guide rail internal expansion support positioning device (1), the second hydraulic cylinder 41 of the support tailstock is started to prop up the tail end of the guide rail internal expansion support positioning device (1), and the stroke of the support tailstock support rod is adjusted to ensure that the coaxiality of the head and tail of the box is not greater than 0.2 mm; S122: Adjust the relative position of the box skin and the guide rail to ensure that the installation position of the box skin and the guide rail meets the requirements of the parts drawing.

Images