Large-layout ultrathin double-layer hollow steel plate label welding process

Abstract

The invention relates to a welding process for a large-layout ultrathin double-layer hollow steel plate label, which comprises the steps of surface treatment, windowing, pre-welding of a reinforcing rib plate, overlapping and positioning, first welding of a window, secondary welding of the window, peripheral sealing and the like, and particularly comprises the following steps of: respectively welding two sides of the reinforcing rib plate at a welding window of a double-layer steel plate; on the premise that the material reduction amount of a single-side steel plate is extremely small, local strength loss caused by windowing is counteracted through double-side welding, and the overall rigidity of the sign is high; the reinforcing rib plate realizes effective connection and reinforcement between the two layers of steel plates, solves the problem of insufficient structural strength of a large-layout ultrathin double-layer hollow steel plate label, and has the advantages of improving the structural strength, preventing the middle part from being shrunken and realizing large-area label manufacturing.

Description

Technical Field

[0001] The invention relates to the technical field of steel plate welding, and in particular to a welding process for a large-format ultra-thin double-layer hollow steel plate sign. Background Art

[0002] The ultra-thin double-layer steel plate in the sign production is made of two layers of extremely thin steel plates bonded together by bonding or compounding technology. Due to its lightweight design, it is particularly suitable for hanging, pasting or fixing in areas with limited load-bearing (such as glass curtain walls, indoor walls, etc.), and the double-layer design can effectively solve the problem of single-layer thin plates being easily deformed and concave. However, it is difficult to make ultra-thin double-layer hollow steel plate signs with a large layout with the existing production process. This is because the large size and limited thickness of the steel plate surface make it difficult to insert the welding gun to weld the connection structure (usually ribs or columns) between the double-layer steel plates to enhance the stability between the double-layer steel plates. When the size is too large, the sign is prone to excessive local deflection in the middle due to factors such as wind pressure and deadweight, and is easy to deform and concave. Summary of the invention

[0003] 1. Technical issues to be solved

[0004] The purpose of the present invention is to provide a large-format ultra-thin double-layer hollow steel plate sign welding process, which has the advantages of improving structural strength, preventing the middle part from being concave, and realizing the production of large-area signs.

[0005] 2. Technical Solution

[0006] The present invention is achieved through the following technical solutions:

[0007] According to a first aspect of the present invention, a large-format ultra-thin double-layer hollow steel plate sign welding process is provided, comprising the following steps:

[0008] S1 Surface treatment: Pre-treatment of the outer surface of the steel plate by sandblasting;

[0009] S2 window opening: opening welding windows for the welding gun head to pass through at multiple preset positions on the inner surface of the steel plate, and the welding windows are inclined at a preset inner inclination angle θ;

[0010] S3 Pre-welding of reinforcing ribs: weld the reinforcing ribs in parallel on one side close to the welding window, reserve welding grooves on both sides of the top edge of the reinforcing ribs, control a rib window spacing d between the welding window and the reinforcing ribs, and control the rib window spacing d and the inner inclination angle θ so that the welding gun head can face the welding groove after passing through the welding window;

[0011] S4 Overlapping and positioning: Use a magnetic fixture to overlap and position the two steel plates so that the end faces of the reinforcing ribs of the two steel plates are in contact with each other;

[0012] S5 window first pass welding: insert the welding gun head through the welding window of the upper steel plate to between the two steel plates, move the welding gun along the welding window, and perform the first pass welding between one side of the contacting reinforcing ribs;

[0013] S6 window secondary welding: turn over the workpiece, insert the welding gun head from the welding window of the lower steel plate to between the two steel plates, move the welding gun along the welding window, and weld the other side of the reinforcing ribs that are in contact with each other;

[0014] S7 Peripheral Closure: Use continuous fillet welds to weld the four peripheral strips between the edges of two steel plates.

[0015] According to an embodiment of the present invention, the rib window spacing d=H*tanθ+δ, wherein H is the height of the reinforcing rib plate; θ is the inclination angle, which is 30° to 45°; and δ is the safety margin, which is 3-5 mm.

[0016] According to an embodiment of the present invention, the parameters of the reinforcing ribs satisfy: the rib height H is 1.2 to 4 times the steel plate thickness t, the rib spacing L≤(2Et)^(1 / 2); the groove angle α is 45°±5°, where t is the steel plate thickness; E is the elastic modulus, and α is the allowable stress.

[0017] According to an embodiment of the present invention, in step S3, CO 2 Use gas shielded welding to weld the reinforcing ribs. The welding sequence is from the center to the edge, and the spacing distance is ≥300mm.

[0018] According to an embodiment of the present invention, in step S4, the groove alignment deviation of the reinforcing rib is controlled to be ≤0.5mm; after the two steel plates are overlapped and positioned, four peripheral strips are welded between the edges of the two steel plates through temporary welding spots, and the spacing between the temporary positioning welding spots is ≤1000mm.

[0019] According to an embodiment of the present invention, in steps S5 and S6, the welding current is controlled at 150A-180A, and the welding speed is controlled at 8-12cm / min; at the same time, the interlayer temperature of the two layers of steel plates is monitored by a short-wave infrared thermal imager with a sampling frequency of 50Hz. When the interlayer temperature is detected to be greater than 140°C, the welding current is automatically reduced by 5%-8%, and compressed air is blown obliquely 30cm away from the weld to assist cooling.

[0020] According to an embodiment of the present invention, in step S7, the weld foot height K=0.7t and K≥4mm, and the welding speed is controlled at 25-35cm / min.

[0021] According to an embodiment of the present invention, in step S2, the welding windows are basically opened at intervals along the width direction of the steel plate; in step S3, the reinforcing ribs have thick plate sections and thin plate sections that are spaced apart, and the thick plate sections and the sides of the thin plate sections correspond to parallel welding windows, and the rib window spacing d between the thick plate sections, the thin plate sections and the welding windows is controlled to be equal.

[0022] According to an embodiment of the present invention, in step S4, before the two steel plates are overlapped and positioned, sleeves and auxiliary positioning rods are respectively welded at several predetermined points of the two steel plates. When the two steel plates are overlapped, the auxiliary positioning rods are inserted into the welded sleeves to ensure that the end faces of the reinforcing ribs of the two steel plates are accurately aligned.

[0023] 3. Beneficial Effects

[0024] One or more of the above embodiments have the following advantages or beneficial effects:

[0025] A large-format ultra-thin double-layer hollow steel plate sign welding process according to an embodiment of the present invention includes the steps of surface treatment, window opening, pre-welding of reinforcing ribs, overlapping positioning, first-pass window welding, secondary window welding and peripheral sealing, especially welding both sides of the reinforcing ribs at the welding window of the double-layer steel plate, so that double-sided welding can be achieved to offset the local strength loss caused by window opening with minimal material reduction on one side of the steel plate, so that the overall rigidity of the sign is relatively high; the reinforcing ribs achieve effective connection and reinforcement between the two layers of steel plates, solves the problem of insufficient structural strength of large-format ultra-thin double-layer hollow steel plate signs, and has the advantages of improving structural strength, preventing the middle part from being concave, and achieving large-area sign production. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above contents and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0027] Figure 1 It is the flow chart of the process of the present invention

[0028] Figure 2 It is an exploded view of the ultra-thin double-layer hollow steel plate sign;

[0029] Figure 3 It is a side perspective view of the overlapping and positioning of the double-layer steel plates;

[0030] Figure 4 It is a structural schematic diagram of an implementation method of a pre-welded window layout of a reinforced rib plate;

[0031] 1. Steel plate; 2. Edge strip; 3. Reinforcing rib; 3a. Thin plate section; 3b. Thick plate section; 4. Welding window; 5. Casing; 6. Auxiliary positioning rod. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0033] An embodiment of the present invention provides a large-format ultra-thin double-layer hollow steel plate sign welding process, comprising the following steps:

[0034] S1 surface treatment: The outer surface of steel plate 1 is sandblasted to Sa2.5 cleanliness level, and the surface flatness tolerance of steel plate 1 is ≤1.5mm / m 2 Among them, sandblasting ensures that the oxide layer removal rate of the welding surface is more than 98%, and controls the plane tolerance and the pre-compensation amount of welding deformation to ensure the quality of subsequent welding.

[0035] S2 window opening: a welding window 4 is opened at multiple preset positions on the inner surface of the steel plate 1 for the welding gun head to pass through, and the welding window 4 is opened at a preset inner inclination angle θ; the preset positions are staggered and distributed on the surface of the steel plate 1 to form a discontinuous stress concentration point; the width of the welding window 4 is not higher than 5mm, and the welding windows 4 are opened in a pipeline manner in the same way on multiple steel plates 1 to improve production efficiency;

[0036] S3 Pre-welding of reinforcing ribs: weld the reinforcing ribs 3 in parallel on one side close to the welding window 4 to improve local stiffness; wherein, welding grooves are reserved on both sides of the top edge of the reinforcing ribs 3, and a rib window spacing d is controlled between the welding window 4 and the reinforcing ribs 3 to ensure the stability of the welding wire extension length. The rib window spacing d and the inclination angle θ control the welding gun to make the welding gun head just face the welding groove after passing through the welding window 4; wherein, the rib window spacing is the distance from the center of the welding window 4 to the edge of the reinforcing rib 3, the length of the welding window 4 is not less than the reinforcing rib 3, and the angle between the axis of the welding gun and the normal of the welding groove is ≤15°.

[0037] S4 superposition positioning: Use a magnetic clamp to superimpose and position the two steel plates 1, reduce the amount of assembly misalignment, and then make the end faces of the reinforcing ribs 3 of the two steel plates 1 contact each other to form a three-dimensional grid support structure; after the two steel plates 1 are relatively superimposed, the welding windows 4 are just located on both sides of the reinforcing ribs 3, which is convenient for welding the joints between the reinforcing ribs 3 from both sides in sequence;

[0038] S5 Window first pass welding: insert the welding gun head through the welding window 4 of the upper steel plate 1 to the space between the two steel plates 1, move the welding gun along the welding window 4, and perform the first pass welding between one side of the reinforcing ribs 3 that are in contact with each other; through the reserved welding window 4, the hard-to-reach parts of the two steel plates 1 can be welded together through the reinforcing ribs 3, and the existence of the inclination angle θ facilitates the control of the welding gun direction, thereby improving the welding accuracy and speed;

[0039] S6 Window Secondary Welding: Hoist and flip the workpiece, insert the welding gun head from the welding window 4 of the lower steel plate 1 to the space between the two steel plates 1, move the welding gun along the welding window 4, weld the other side of the reinforcing rib 3 in contact, and weld the two sides of the reinforcing rib 3 at the welding window 4 of the double-layer steel plate. Under the premise of very little material reduction on one side of the steel plate, double-sided welding is achieved to offset the local strength loss caused by the window opening, so that the overall rigidity of the sign is relatively high;

[0040] S7 Peripheral sealing: Use continuous fillet welds to weld the four peripheral strips 2 between the edges of two steel plates 1 to establish a complete sealed cavity to ensure the sealing and strength of the overall structure.

[0041] Specifically, the rib window spacing d=H*tanθ+δ, wherein H is the height of the reinforcing rib 3; θ is the inclination angle, which is 30° to 45°; and δ is the safety margin, which is 3-5 mm to compensate for tooling tolerance.

[0042] Among them, the parameters of the reinforcing rib 3 meet the following requirements: the rib height H is 1.2 to 4 times the thickness t of the steel plate 1, and the rib spacing L≤(2Et)^(1 / 2) to control the local buckling critical load; the groove angle α is 45°±5°, where t is the thickness of the steel plate 1; E is the elastic modulus and α is the allowable stress.

[0043] In step S3, CO 2 The reinforcing rib 3 is welded by gas shielded welding, and the welding sequence is from the center to the edge with a spacing of ≥300mm to reduce the thermal deformation and prevent the overlap of the heat affected zone.

[0044] Preferably, in step S4, the groove alignment deviation of the reinforcing rib 3 is controlled to be ≤0.5mm to achieve precision welding; after the two steel plates 1 are overlapped and positioned, the surrounding strips 2 are welded between the edges of the two steel plates 1 through temporary welding points, and the spacing between the temporary positioning welding points is ≤1000mm to ensure the accurate positioning of the overall structure of the sign.

[0045] Furthermore, in steps S5 and S6, the welding current is controlled at 150A-180A, and the welding speed is controlled at 8-12cm / min; at the same time, the interlayer temperature of the two layers of steel plates 1 is monitored by a short-wave infrared thermal imager with a sampling frequency of 50Hz to achieve intelligent thermal management. When the interlayer temperature is detected to be greater than 140°C, the welding current is automatically reduced by 5%-8%, and compressed air is blown obliquely at a distance of 30cm from the weld to assist cooling to ensure welding quality.

[0046] In step S7, the weld foot height K=0.7t and K≥4mm, and the welding speed is controlled at 25-35cm / min.

[0047] According to an embodiment of the present invention, in step S2, the welding windows 4 are basically opened at intervals along the width direction of the steel plate 1, so as to reduce the stress concentration of the opening and facilitate the destruction of the overall deformation of the steel plate 1; in step S3, the reinforcing rib 3 has a thick plate section 3b and a thin plate section 3a arranged at intervals, and the thick plate section 3b and the side of the thin plate section 3a correspond to parallel welding windows 4, and the rib window spacing d between the thick plate section 3b, the thin plate section 3a and the welding window 4 is controlled to be equal, so as to facilitate the welding robot to quickly extend into the welding window 4 for welding at the same welding angle.

[0048] According to an embodiment of the present invention, in step S4, before the two steel plates 1 are overlapped and positioned, sleeves 5 and auxiliary positioning rods 6 are respectively welded at several predetermined points of the two steel plates 1. When the two steel plates 1 are overlapped, the auxiliary positioning rods 6 are inserted into the sleeves 5 to ensure that the end faces of the reinforcing ribs 3 of the two steel plates 1 are accurately aligned.

[0049] The process provided by the present invention can quickly and mass-produce large-format ultra-thin double-layer hollow steel plate signs with high structural strength and not easy to deform. In this process, a gridded reinforcing rib 3 is preset inside the double-layer steel plate, and the mechanical weak points of the area and shape of the sign are matched through mathematical modeling to achieve on-demand directional reinforcement; through the staggered distribution of micro-welding windows 4, in conjunction with the inclined window opening process, only tiny traces are left on the surface of the sign after welding is completed, and a visually seamless effect is achieved after spraying; the welding windows 4 opened on the surface are retained, and the honeycomb ventilation channels formed between the double-layer structures can reduce the wind pressure load on the windward surface. In hot weather, the welding windows 4 allow air convection inside and outside the sign to reduce the surface temperature rise and avoid expansion and peeling of the coating caused by high temperature.

[0050] It should be understood that the cutting device according to the embodiment of the present invention has all the characteristics and advantages of the above-mentioned alignment mechanism. For details, please refer to the above description, which will not be repeated here.

[0051] It will be appreciated by those skilled in the art that the features described in the various embodiments of the present invention may be combined and / or combined in various ways, even if such combinations and / or combinations are not explicitly described in the present invention. In particular, without departing from the spirit and teachings of the present invention, the features described in the various embodiments of the present invention may be combined and / or combined in various ways. All of these combinations and / or combinations fall within the scope of the present invention.

Claims

1. A large-format ultra-thin double-layer hollow steel plate sign welding process, characterized in that: The steps include: S1 Surface treatment: Pre-treatment of the outer surface of the steel plate by sandblasting; S2 window opening: opening welding windows for the welding gun head to pass through at multiple preset positions on the inner surface of the steel plate, and the welding windows are inclined at a preset inner inclination angle θ; S3 Pre-welding of reinforcing ribs: weld the reinforcing ribs in parallel on one side close to the welding window, reserve welding grooves on both sides of the top edge of the reinforcing ribs, control a rib window spacing d between the welding window and the reinforcing ribs, and control the rib window spacing d and the inner inclination angle θ so that the welding gun head can face the welding groove after passing through the welding window; S4 Overlapping and positioning: Use a magnetic fixture to overlap and position the two steel plates so that the end faces of the reinforcing ribs of the two steel plates are in contact with each other; S5 window first pass welding: insert the welding gun head through the welding window of the upper steel plate to between the two steel plates, move the welding gun along the welding window, and perform the first pass welding between one side of the contacting reinforcing ribs; S6 window secondary welding: turn over the workpiece, insert the welding gun head from the welding window of the lower steel plate to between the two steel plates, move the welding gun along the welding window, and weld the other side of the reinforcing ribs that are in contact with each other; S7 Peripheral Closure: Use continuous fillet welds to weld the four peripheral strips between the edges of two steel plates.

2. According to claim 1, a large-format ultra-thin double-layer hollow steel plate sign welding process is characterized in that: The rib window spacing d = H*tanθ+δ, where: H is the height of the reinforcing rib; θ is the inclination angle, which is 30°~45°; δ is the safety margin, which is 3-5mm.

3. The large-format ultra-thin double-layer hollow steel plate sign welding process according to claim 1 is characterized in that: The parameters of the reinforcing ribs are as follows: the rib height H is 1.2 to 4 times the steel plate thickness t, the rib spacing L ≤ (2Et) ^ (1 / 2); the groove angle α is 45° ± 5°, where: t is the thickness of the steel plate; E is the elastic modulus, and α is the allowable stress.

4. The large-format ultra-thin double-layer hollow steel plate sign welding process according to claim 1 is characterized in that: In step S3, CO2 gas shielded welding is used to weld the reinforcing ribs, and the welding sequence is from the center to the edge, with an interval distance of ≥300 mm.

5. The large-format ultra-thin double-layer hollow steel plate sign welding process according to claim 1 is characterized in that: In step S4, the groove alignment deviation of the reinforcing rib is controlled to be ≤0.5mm; after the two steel plates are overlapped and positioned, four peripheral strips are welded between the edges of the two steel plates through temporary welding points, and the spacing between the temporary positioning welding points is ≤1000mm.

6. The large-format ultra-thin double-layer hollow steel plate sign welding process according to claim 1 is characterized in that: In steps S5 and S6, the welding current is controlled at 150A-180A, and the welding speed is controlled at 8-12cm / min; at the same time, the interlayer temperature of the two layers of steel plates is monitored by a short-wave infrared thermal imager with a sampling frequency of 50Hz. When the interlayer temperature is detected to be greater than 140°C, the welding current is automatically reduced by 5%-8%, and compressed air is blown obliquely 30cm away from the weld to assist cooling.

7. The large-format ultra-thin double-layer hollow steel plate sign welding process according to claim 1 is characterized in that: In step S7, the weld foot height K=0.7t and K≥4mm, and the welding speed is controlled at 25-35cm / min.

8. A large-format ultra-thin double-layer hollow steel plate sign welding process according to any one of claims 1 to 7, characterized in that: In step S2, the welding windows are basically opened at intervals along the width direction of the steel plate; in step S3, the reinforcing ribs have thick plate sections and thin plate sections that are spaced apart, and the thick plate sections and the sides of the thin plate sections have corresponding parallel welding windows, and the rib window spacing d between the thick plate sections, the thin plate sections and the welding windows is controlled to be equal.

9. The large-format ultra-thin double-layer hollow steel plate sign welding process according to claim 1 is characterized in that: In step S4, before the two steel plates are overlapped and positioned, sleeves and auxiliary positioning rods are welded at several predetermined points of the two steel plates. When the two steel plates are overlapped, the auxiliary positioning rods are inserted into the sleeves to ensure that the end faces of the reinforcing ribs of the two steel plates are accurately aligned.

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