Welding method and system

Abstract

The present application relates to the technical field of welding, and provides a welding method and system.The method comprises the following steps: selecting at least two plates with thickness difference, forming a conductive silver-based layer on one side of the plate with the thinnest thickness, coating adhesive on the other side of the plate with the thinnest thickness, and bonding the remaining plates to the bonding side of the plate with the thinnest thickness; sticking a backing plate to the outer surface of the conductive silver-based layer; selecting a first electrode rod and a second electrode rod with different diameters, and placing the first electrode rod and the second electrode rod on the outer side of the backing plate and the outer side of the remaining plates respectively; setting welding parameters based on the thickness parameters of the plates, and welding the plates according to the welding parameters.The diameter of the first electrode rod is smaller than that of the second electrode rod.Not only the air tightness is improved, but also the penetration rate of the thin plate side is increased from the original 20% to 50%, the penetration rate is greatly improved, the welding between the plates is more stable, and the product quality is improved.

Description

Technical Field

[0001] This invention relates to the field of welding technology, and in particular to a welding method and system. Background Technology

[0002] With the rapid development of rail transit equipment, the application of vehicle materials has become more diversified, alloy systems are becoming increasingly complex, and the requirements for welding technology are becoming increasingly stringent. Traditional spot welding suffers from insufficient airtightness of vehicles and low penetration of plates, making it difficult to adapt to the rapid development of next-generation subways and high-speed railways. Summary of the Invention

[0003] This invention provides a welding method to solve the technical problems of insufficient weld air tightness and low penetration rate in the prior art, so as to achieve good air tightness of the vehicle body and improve the penetration rate of the thin plate side, thereby improving product quality.

[0004] The present invention also provides a welding system.

[0005] This invention provides a welding method, comprising the following steps:

[0006] Select at least two plates with a thickness difference, and form a conductive silver base layer on one side of the thinnest plate.

[0007] Apply adhesive to the other side of the thinnest sheet and then bond the remaining sheets to the bonding side of the thinnest sheet.

[0008] A pad is attached to the outer surface of the conductive silver base layer;

[0009] Select a first electrode rod and a second electrode rod with different diameters, and place the first electrode rod and the second electrode rod on the outside of the pad and the outside of the remaining plates, respectively, wherein the diameter of the first electrode rod is smaller than the diameter of the second electrode rod;

[0010] Welding parameters are set based on the thickness parameters of the plate material, and at least the plate material is welded according to the welding parameters.

[0011] According to a welding method provided by the present invention, the step of selecting at least two plates with a thickness difference and forming a conductive silver substrate on one side of the thinnest plate specifically includes:

[0012] Two plates with a thickness difference are selected, namely a thin plate and a thick plate. A conductive silver-based material is coated on the outer surface of the thin plate to form a conductive silver base layer with a thickness of 10-20μm. The thick plate is then attached to the side of the thin plate away from the conductive silver base layer.

[0013] Wherein, the thickness of the thin plate is t1, and the thickness of the thick plate is t2;

[0014] Wherein, 2t1>t2>t1, and the thickness of the pad is 0.3mm;

[0015] Alternatively, t2 > 3t1, and the thickness of the pad is 0.5 mm.

[0016] According to a welding method provided by the present invention, the step of selecting at least two plates with a thickness difference and forming a conductive silver substrate on one side of the thinnest plate specifically includes:

[0017] Three plates with different thicknesses are selected, namely a thin plate, a relatively thick plate, and a thick plate. A conductive silver-based material is coated on the outer surface of the thin plate to form a conductive silver base layer with a thickness of 10-20μm. The thick plate and the relatively thick plate are attached to the side of the thin plate away from the conductive silver base layer.

[0018] Wherein, the thickness of the thin plate is t3, the thickness of the thicker plate is t4, and the thickness of the thickest plate is t5;

[0019] Where t5 > t4 > t3, and t5 > 3t3, the thickness of the pad is 0.8 mm.

[0020] According to a welding method provided by the present invention, the step of applying adhesive to the other side of the thinnest plate and bonding the remaining plates to the bonding side of the thinnest plate specifically includes:

[0021] An adhesive is prepared using compounded rubber, titanium dioxide, and conductive carbon black as the base materials. The areas to be welded on the plates are determined, and the adhesive is applied to the areas to be welded on the thinnest plate. After aligning the areas to be welded on the remaining plates with the areas to be welded on the thinnest plate, all plates are pressed together, and a cleaning mechanism is used to clean the adhesive that has overflowed from the edges of the plates.

[0022] According to a welding method provided by the present invention, the step of applying adhesive to the welding area of ​​the thinnest plate specifically includes:

[0023] Apply adhesive to the thinnest sheet material at multiple single-point intervals along the area to be welded.

[0024] The weight of adhesive used in each single-point application is 1g, and the adhesive used in each single-point application forms a circular coating area on the board, the diameter of which is 4.5-5.0mm.

[0025] According to a welding method provided by the present invention, the step of applying adhesive to the welding area of ​​the thinnest plate specifically includes:

[0026] Continuous adhesive application is performed on the thinnest sheet material along the area to be welded;

[0027] The adhesive used at the corresponding spot welding position in the continuous adhesive coating area weighs 1g, and the width of the continuous adhesive coating area is 4.5-5.0mm.

[0028] According to a welding method provided by the present invention, the step of attaching a pad to the outer surface of the conductive silver substrate specifically includes:

[0029] The pad is attached and fixed to the outer surface of the conductive silver base layer by at least one of the following methods: bonding, tooling, and fastener fixing;

[0030] The thickness of the pad is 0.3-0.8 mm.

[0031] According to a welding method provided by the present invention, the step of selecting a first electrode rod and a second electrode rod with different diameters, and placing the first electrode rod and the second electrode rod on the outer side of the pad and the outer side of the remaining plate, respectively, specifically includes:

[0032] Select an electrode with a diameter of 8 mm and an end spherical radius of 200 mm as the first electrode rod, and select an electrode with a diameter of 16 mm and an end spherical radius of 200 mm as the second electrode rod. Place the first electrode rod and the second electrode rod on the outside of the pad and the outside of the remaining plates, respectively.

[0033] According to a welding method provided by the present invention, the step of setting welding parameters based on the thickness parameter of the plate and welding at least the plate according to the welding parameters specifically includes:

[0034] Based on the thickness parameters of the thinner of the two outermost plates, the weld spacing, weld-to-edge distance, welding current, welding time, cooling time, pulse count, holding time, and electrode pressure are set, and at least two plates are welded using the first electrode rod and the second electrode rod with preset welding current, welding time, cooling time, pulse count, holding time, and electrode pressure.

[0035] The present invention also provides a welding system, comprising:

[0036] Central control unit;

[0037] The coating unit, electrically connected to the central control unit, is used to form a conductive silver base layer on one side of the thinnest sheet material.

[0038] The adhesive application unit, electrically connected to the central control unit, is used to apply adhesive to the other side of the thinnest sheet material.

[0039] The mounting unit is electrically connected to the central control unit and is used to attach a pad to the outer surface of the conductive silver base layer.

[0040] The parameter setting unit is electrically connected to the central control unit and is used to set welding parameters based on the thickness parameters of the plate.

[0041] The first electrode rod and the second electrode rod are electrically connected to the central control unit, respectively, and are used to weld at least two plates on the outside of the pad and the outside of the remaining plates.

[0042] The welding method provided in this invention improves the resistivity of the thinnest plate by forming a conductive silver base layer on its outer side, thereby enhancing nucleation ability and increasing the penetration rate of the thin plate. Adhesive bonding before welding ensures excellent airtightness, overcoming the engineering limitation of non-sealing spot welding on rail vehicle bodies. Adding a backing plate reduces heat dissipation on the thin plate during spot welding, further improving penetration. Simultaneously, spot welding using first and second electrode rods of different diameters, with the smaller diameter first electrode rod positioned on the thin plate side, further reduces heat dissipation, causing the weld nugget to shift towards the thin plate side, thus increasing penetration. Through the synergistic effect of these multiple methods, not only is airtightness improved, but the penetration rate on the thin plate side is increased from 20% to 50%, significantly enhancing penetration and resulting in more stable welding between plates and improved product quality.

[0043] The welding system provided in this invention improves the resistivity of the thinnest plate by forming a conductive silver base layer on its outer side, thereby enhancing nucleation ability and improving the penetration rate of the thin plate. Adhesive bonding of the plates before welding ensures excellent airtightness, overcoming the engineering limitation of non-sealing spot welding on rail vehicle bodies. Adding a backing plate reduces heat dissipation on the thin plate side during spot welding, further improving penetration. Simultaneously, spot welding using first and second electrode rods of different diameters, with the smaller diameter first electrode rod positioned on the thin plate side, further reduces heat dissipation, causing the weld nugget to shift towards the thin plate side, thus improving penetration. Through the synergistic effect of these multiple methods, not only is airtightness improved, but the penetration rate on the thin plate side is increased from 20% to 50%, significantly enhancing penetration and resulting in more stable welding between plates and improved product quality. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0045] Figure 1 This is a schematic flowchart of the welding method provided by the present invention;

[0046] Figure 2 This is a schematic diagram of the welding system provided by the present invention;

[0047] Figure 3 This is a schematic diagram showing the state of the first and second electrode rods welding two plates.

[0048] Figure 4 This is a schematic diagram of the melt penetration rate of the thin plate when the diameters of the first electrode rods are 12mm, 10mm and 8mm respectively, and the second electrode rod is always kept at 16mm.

[0049] Figure 5 This is a graph showing the relationship between weld spot spacing and weld nugget diameter in the welding method provided by this invention and in traditional welding methods;

[0050] Figure 6 This is a curve showing the welding point spacing and the maximum tensile shear force in the welding method provided by this invention and the traditional welding method. Detailed Implementation

[0051] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0052] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0053] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0054] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0055] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0056] The following is combined with Figures 1-6 The welding method of the present invention includes the following steps:

[0057] S100. Select at least two plates with a thickness difference and form a conductive silver base layer on one side of the thinnest plate.

[0058] S200. Apply adhesive to the other side of the thinnest sheet and bond the remaining sheets to the bonding side of the thinnest sheet.

[0059] S300, A pad is attached to the outer surface of the conductive silver base layer.

[0060] S400. Select a first electrode rod and a second electrode rod with different diameters, and place the first electrode rod and the second electrode rod on the outside of the pad and the outside of the remaining plates, respectively.

[0061] The diameter of the first electrode rod is smaller than the diameter of the second electrode rod.

[0062] S500: Set welding parameters based on the thickness parameters of the sheet metal, and weld at least the sheet metal according to the welding parameters.

[0063] In this embodiment, by forming a conductive silver base layer on the outer side of the thinnest sheet, the resistivity of the thin sheet side can be increased to enhance nucleation ability, thereby improving the penetration rate of the thin sheet side. Using adhesive to bond the sheets before subsequent welding ensures good airtightness of the welded components, overcoming the engineering limitation of non-sealing spot welding on rail vehicle bodies. Adding a backing plate reduces the heat dissipation rate on the thin sheet side during spot welding, further improving the penetration rate. Simultaneously, spot welding based on first and second electrode rods of different diameters, with the smaller diameter first electrode rod positioned on the thin sheet side, further reduces heat dissipation, causing the weld nugget to shift towards the thin sheet side, thus improving the penetration rate. Through the synergistic effect of these multiple methods, not only is airtightness improved, but the penetration rate on the thin sheet side is also increased from 20% to 50%, significantly enhancing the penetration rate and making the welding between sheets more stable, thus improving product quality.

[0064] This welding method is particularly suitable for spot welding between two plates with a thickness difference greater than 3 mm. It is also especially suitable for spot welding and fixing between two or three plates.

[0065] like Figure 3 As shown, this is a welding process between two plates. The upper plate is thin, and the lower plate is thick. The electrode rod at the top of the thin plate is a first electrode rod with a smaller diameter, and the electrode rod at the bottom of the thick plate is a second electrode rod with a larger diameter. After coating the upper surface of the thin plate with a conductive silver base layer and attaching a backing plate, the weld nugget is shifted towards the thin plate, improving the penetration rate of the thin plate and enhancing the connection quality between the two plates after welding.

[0066] The main component of the conductive silver substrate is silver tin oxide (AgSnO2). Silver tin oxide can increase the contact resistance of the material surface, thereby increasing the resistivity of the thinnest plate side. Under the same spot welding parameters, the greater the contact resistance, the stronger the nucleation ability, thus improving the nucleation ability of the thin plate side and increasing the penetration rate of the thin plate side.

[0067] The aforementioned adhesive side of the thinnest sheet refers to the side of the thinnest sheet coated with adhesive.

[0068] This embodiment takes two plates as an example, selecting at least two plates with a thickness difference, and forming a conductive silver base layer on one side of the thinnest plate. Specifically, this includes:

[0069] Select two plates with a thickness difference, namely a thin plate and a thick plate. Coat the outer surface of the thin plate with a conductive silver base material to form a conductive silver base layer with a thickness of 10-20 μm. Then attach the thick plate to the side of the thin plate away from the conductive silver base.

[0070] When welding two plates, the thinner plate can be placed on top of the thicker plate, and a conductive silver-based material can be coated on the upper surface of the thinner plate to form a conductive silver base layer. During the welding process, the conductive silver base layer can increase the contact resistance on the thinner plate side, improve the nucleation ability on the thinner plate side, so that the weld nugget is located at the junction of the thinner and thicker plates, thereby improving the penetration rate on the thinner plate side and improving the welding quality.

[0071] At this point, with the pad on the outer surface of the conductive silver base layer and the asymmetrically arranged first and second electrode rods, the melting penetration rate can be increased from the original 20% to 50%.

[0072] The thickness of the thin plate is t1, and the thickness of the thick plate is t2. When 2t1 > t2 > t1, the thickness of the backing plate is 0.3 mm. When t2 > 3t1, the thickness of the backing plate is 0.5 mm. The thickness of the backing plate varies based on the thickness of the thin and thick plates. When the thickness of the thick plate is slightly greater than that of the thin plate (it should be noted that "slightly greater" here also requires that the thickness of the thick plate is at least 3 mm greater than that of the thin plate), the thickness of the backing plate can be set to 0.3 mm. In this case, the backing plate has the best effect on reducing the heat dissipation rate on the thin plate side and meets the welding requirements. When the thickness of the thick plate is much greater than that of the thin plate, the thickness of the backing plate can be set to 0.5 mm. In this case, the backing plate has the best effect on reducing the heat dissipation rate on the thin plate side and meets the welding requirements.

[0073] This embodiment takes three plates as an example, selecting at least two plates with a thickness difference, and forming a conductive silver base layer on one side of the thinnest plate. Specifically, this includes:

[0074] Select three plates with different thicknesses: a thin plate, a relatively thick plate, and a thick plate. Coat the outer surface of the thin plate with a conductive silver-based material to form a conductive silver base layer with a thickness of 10-20μm. Then attach the thick plate and the relatively thick plate to the side of the thin plate away from the conductive silver base layer.

[0075] When welding three plates, the thinner plate can be placed on top of the thicker plate, and the thicker plate below it, sandwiching the thicker plate between the thinner and thicker plates. A conductive silver-based material is then coated onto the upper surface of the thinner plate, forming a conductive silver base layer. During welding, the conductive silver base layer increases the contact resistance on the thinner plate side, enhancing its nucleation ability. This allows the thicker plate to be melted through during nucleation, and also ensures that the thinner and thicker plates can be melted towards the thicker plate, thus improving the penetration rate on the thinner plate side and enhancing the weld quality.

[0076] At this point, with the pad on the outer surface of the conductive silver base layer and the asymmetrically arranged first and second electrode rods, the melting penetration rate can be increased from the original 20% to 50%.

[0077] The thickness of the thin plate is t3, the thickness of the thicker plate is t4, and the thickness of the thickest plate is t5. When t5 > t4 > t3, and t5 > 3t3, the thickness of the backing plate is 0.8 mm. At this thickness, the backing plate best reduces the heat dissipation rate on the thin plate side while still meeting welding requirements.

[0078] According to the welding method provided by the present invention, the step of applying adhesive to the other side of the thinnest plate and bonding the remaining plates to the bonding side of the thinnest plate specifically includes:

[0079] An adhesive is prepared using compounded rubber, titanium dioxide, and conductive carbon black as the base materials. The areas to be welded on the plates are determined, and the adhesive is applied to the areas to be welded on the thinnest plate. After aligning the areas to be welded on the remaining plates with the areas to be welded on the thinnest plate, all plates are pressed together, and a cleaning mechanism is used to clean the adhesive that has overflowed from the edges of the plates.

[0080] An adhesive is prepared using a mixture of rubber, titanium dioxide, and conductive carbon black. The resulting adhesive exhibits excellent spreadability and initial adhesion, and does not drip at any spot welding station. It should be noted that the spot welding stations referred to here include stations in horizontal, vertical, and inverted positions.

[0081] The aforementioned adhesive allows for precise control of the adhesive dispensing diameter, enabling subsequent spot welding within three days of application. It can withstand the impact and erosion of pretreatment solutions (cleaning solutions, rust removers, and phosphating solutions, etc.) and electrophoretic solutions, ensuring no dispersion or contamination. It also exhibits compatibility with arc welding, flame adjustment, and repair processes.

[0082] This adhesive, made from compounded rubber, titanium dioxide, and conductive carbon black, also possesses strong electrical conductivity, ensuring it doesn't affect the quality of subsequent spot welding and exhibits a certain tolerance for varying degrees of cleanliness on the sheet surface. Furthermore, it exhibits high flame retardancy, maintaining good stability and sealing even at 1000℃ spot welding temperatures without producing open flames.

[0083] The aforementioned adhesive is also non-toxic and odorless, and will not affect the health of operators. Excess spot welding sealant is easy to clean. Furthermore, it has good storage stability and a shelf life of up to 180 days.

[0084] Understandably, before bonding the boards, the bonding positions need to be determined, and these positions are based on the locations of the areas to be welded. Specifically, the areas to be welded are determined based on the locations of the weld points for each spot weld, and these areas are spaced-out dot-like regions.

[0085] After applying adhesive to the welding area of ​​the thinnest sheet, the remaining sheets are bonded to the thinnest sheet, and the welding areas of the thinnest sheet are aligned with the welding areas of the remaining sheets to ensure welding reliability.

[0086] Press the thinnest board and the rest of the boards together to bond them together with the adhesive. As the adhesive spreads to the edges and may even overflow during the pressing process, a cleaning device is used to clean up the overflowing adhesive after bonding to ensure the aesthetics of the boards and to prevent dust and other impurities from adhering to the adhesive edges.

[0087] The cleaning equipment includes, but is not limited to, cleaning brushes, cleaning cloths, and scrapers.

[0088] According to the welding method provided by the present invention, the step of applying adhesive to the welding area of ​​the thinnest plate specifically includes:

[0089] Apply adhesive to the thinnest sheet material at multiple single-point intervals along the area to be welded.

[0090] The weight of adhesive used for each single-point application is 1g, and the adhesive used for each single-point application forms a circular adhesive area on the board with a diameter of 4.5-5.0mm.

[0091] Based on the subsequent spot welding, several spaced areas to be welded are determined. After applying adhesive to each area multiple times, the remaining plates are bonded to the thinnest plate, so that the bonding points coincide with the spot welding points. This ensures that the adhesive and the welding mechanism work together to ensure the airtightness after welding.

[0092] Specifically, the amount of adhesive used for each spot weld is 1g, with a diameter of 4.5-5.0mm, to clearly define the amount and scope of application of the adhesive, ensuring that the adhesive is not wasted due to excessive use, nor that the adhesion is weak due to insufficient use.

[0093] According to the welding method provided by the present invention, the step of applying adhesive to the welding area of ​​the thinnest plate specifically includes:

[0094] Apply adhesive continuously to the thinnest sheet material along the area to be welded;

[0095] The weight of the adhesive used at the corresponding spot welding position in the continuous adhesive coating area is 1g, and the width of the continuous adhesive coating area is 4.5-5.0mm.

[0096] Based on the subsequent spot welding, a straight welding area is formed by connecting several spaced spot welding positions. Continuous linear adhesive is applied along the welding area so that the continuous adhesive can fall into the subsequent spot welding positions, ensuring the stability of the bond, as well as the stability and airtightness after welding.

[0097] Specifically, the amount of adhesive used at the corresponding spot welding position in the continuous adhesive application area is 1g, and the width is 4.5-5.0mm. This clarifies the amount and range of action of the adhesive, ensuring that the adhesive is not wasted due to excessive use, nor that the adhesion is weak due to insufficient use.

[0098] According to the welding method provided by the present invention, the step of attaching a backing plate to the outer surface of a conductive silver substrate specifically includes:

[0099] A pad is attached and fixed to the outer surface of the conductive silver substrate using at least one of the following methods: adhesive bonding, tooling fixation, and fastener fixation. When bonding, the pad can be attached and fixed to the outer surface of the conductive silver substrate by edge bonding, thus facilitating removal of the pad after welding. Removable fixing methods such as tooling fixation and fastener fixation also facilitate removal of the pad after welding. Tooling fixation can employ clamping fixtures that clamp the pad and the substrate at their edges to fix the pad's position. Fasteners can employ clamping locking devices that clamp the pad and the substrate at their edges to fix the pad's position.

[0100] The thickness of the backing plate is 0.3-0.8mm. The specific thickness can be selected according to the aforementioned plate thickness parameters. Furthermore, the shape of the backing plate can be selected based on the shape characteristics of the spot welding area, such as a strip-shaped backing plate or a circular backing plate. The backing plate can be made of stainless steel or copper, and the material can be adjusted to suit the material of the sheet metal.

[0101] According to the welding method provided by the present invention, the step of selecting a first electrode rod and a second electrode rod with different diameters, and placing the first electrode rod and the second electrode rod on the outer side of the pad and the outer side of the remaining plates respectively, specifically includes:

[0102] Select an electrode with a diameter of 8 mm and an end spherical radius of 200 mm as the first electrode rod, and select an electrode with a diameter of 16 mm and an end spherical radius of 200 mm as the second electrode rod. Place the first electrode rod and the second electrode rod on the outside of the pad and the outside of the remaining plates, respectively.

[0103] Spot welding is performed using an 8mm first electrode rod and a 16mm second electrode rod, with the first electrode rod located on the thin plate side and the second electrode rod located on the thick plate side or a relatively thick plate side. This reduces the heat dissipation rate on the thin plate side, shifts the weld nugget towards the thin plate side, and improves the penetration rate on the thin plate side.

[0104] like Figure 4 As shown in the figure, the diameters of the first electrode rods are 12mm, 10mm and 8mm respectively, and the second electrode rod is always kept at 16mm. The figure shows the melting penetration rate of the thin plate side. As can be seen from the figure, when the diameter of the first electrode rod is changed alone, the melting penetration rate (P in the figure) of the first electrode rod with a diameter of 10mm is the highest and the diameter of the fusion area (D in the figure) is the largest.

[0105] The steps of setting welding parameters based on the thickness parameters of the sheet metal, and welding at least the sheet metal according to the welding parameters, specifically include:

[0106] Based on the thickness parameters of the thinner of the two outermost plates, the weld point spacing, weld point to edge distance, welding current, welding time, cooling time, pulse count, holding time, and electrode pressure are set, and at least two plates are welded using the first and second electrode rods with preset welding current, welding time, cooling time, pulse count, holding time, and electrode pressure.

[0107] Understandably, welding is based on the connection between two or more plates. When the plates have different thicknesses, the welding parameters are set based on the thickness of the weldment on the thinner side of the two outermost plates to ensure the reliability of the welding process.

[0108] Taking two plates as an example, one is a thin plate and the other is a thick plate. In this case, the welding parameters are set based on the thickness parameter of the thin plate. The set welding parameters include the weld point spacing, the distance from the weld point to the edge, the welding current, the welding time, the cooling time, the number of pulses, the holding time, and the electrode pressure.

[0109] Taking three plates as an example, the three plates are a thin plate, a relatively thick plate, and a thick plate. The thin plate is placed on top of the thick plate, and the relatively thick plate is placed below the thick plate, so that the thick plate is sandwiched between the thin plate and the relatively thick plate. At this time, the welding parameters are set based on the thickness parameter of the thin plate. The set welding parameters include the weld point spacing, the distance from the weld point to the edge, the welding current, the welding time, the cooling time, the number of pulses, the holding time, and the electrode pressure.

[0110] Based on the thickness of the outermost plate, the parameters for the solder joint spacing and the distance from the solder joint to the edge are set as follows:

[0111]

[0112] like Figure 5 and Figure 6 As shown, when the weld spacing is around 38mm, the diameter of the weld nugget and the maximum tensile shear force after welding are both reduced. Therefore, the spacing value in the range of 36-40mm is discarded when determining the weld spacing.

[0113] On the other hand, the present invention also provides a welding system, including a central control unit, a coating unit, an adhesive application unit, an installation unit, a parameter setting unit, a first electrode rod, and a second electrode rod. The coating unit is electrically connected to the central control unit and is used to form a conductive silver base layer on one side of the thinnest sheet material. The adhesive application unit is electrically connected to the central control unit and is used to apply adhesive to the other side of the thinnest sheet material. The installation unit is electrically connected to the central control unit and is used to attach a pad to the outer surface of the conductive silver base layer. The parameter setting unit, electrically connected to the central control unit, is used to set welding parameters based on the thickness parameters of the sheet material. The first electrode rod and the second electrode rod are respectively electrically connected to the central control unit and are used to weld at least two sheets of material on the outer side of the pad and the outer side of the remaining sheet materials.

[0114] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A welding method, characterized in that, Includes the following steps: Select at least two plates with a thickness difference, and form a conductive silver base layer on one side of the thinnest plate. Apply adhesive to the other side of the thinnest sheet and bond the remaining sheets to the bonding side of the thinnest sheet. Specifically, this includes: preparing an adhesive using compounded rubber, titanium dioxide, and conductive carbon black as the base material; determining the areas of the sheets to be welded; applying the adhesive to the areas of the thinnest sheet to be welded; aligning the areas of the remaining sheets to be welded with the areas of the thinnest sheet to be welded; pressing all the sheets together; and using a cleaning mechanism to clean the adhesive that has overflowed from the edges of the sheets. A pad is attached to the outer surface of the conductive silver base layer; Select a first electrode rod and a second electrode rod with different diameters, and place the first electrode rod and the second electrode rod on the outside of the pad and the outside of the remaining plates, respectively, wherein the diameter of the first electrode rod is smaller than the diameter of the second electrode rod; Welding parameters are set based on the thickness parameters of the plates, and at least two plates are welded according to the welding parameters.

2. The welding method according to claim 1, characterized in that, The step of selecting at least two plates with a thickness difference and forming a conductive silver substrate on one side of the thinnest plate specifically includes: Two plates with a thickness difference are selected, namely a thin plate and a thick plate. A conductive silver-based material is coated on the outer surface of the thin plate to form a conductive silver base layer with a thickness of 10-20μm. The thick plate is then attached to the side of the thin plate away from the conductive silver base layer. Wherein, the thickness of the thin plate is t1, and the thickness of the thick plate is t2; Wherein, 2t1>t2>t1, and the thickness of the pad is 0.3mm; Alternatively, t2 > 3t1, and the thickness of the pad is 0.5 mm.

3. The welding method according to claim 1, characterized in that, The step of selecting at least two plates with a thickness difference and forming a conductive silver substrate on one side of the thinnest plate specifically includes: Three plates with different thicknesses are selected, namely a thin plate, a relatively thick plate, and a thick plate. A conductive silver-based material is coated on the outer surface of the thin plate to form a conductive silver base layer with a thickness of 10-20μm. The thick plate and the relatively thick plate are attached to the side of the thin plate away from the conductive silver base layer. Wherein, the thickness of the thin plate is t3, the thickness of the thicker plate is t4, and the thickness of the thickest plate is t5; Where t5 > t4 > t3, and t5 > 3t3, the thickness of the pad is 0.8 mm.

4. The welding method according to claim 1, characterized in that, The step of applying adhesive to the welding area of ​​the thinnest sheet material specifically includes: Apply adhesive to the thinnest sheet material at multiple single-point intervals along the area to be welded. The weight of adhesive used in each single-point application is 1g, and the adhesive used in each single-point application forms a circular coating area on the board, the diameter of which is 4.5-5.0mm.

5. The welding method according to claim 1, characterized in that, The step of applying adhesive to the welding area of ​​the thinnest sheet material specifically includes: Continuous adhesive application is performed on the thinnest sheet material along the area to be welded; The adhesive used at the corresponding spot welding position in the continuous adhesive coating area weighs 1g, and the width of the continuous adhesive coating area is 4.5-5.0mm.

6. The welding method according to claim 1, characterized in that, The step of attaching the pad to the outer surface of the conductive silver substrate specifically includes: The pad is attached and fixed to the outer surface of the conductive silver base layer by at least one of the following methods: bonding, tooling, and fastener fixing; The thickness of the pad is 0.3-0.8 mm.

7. The welding method according to claim 1, characterized in that, The step of selecting a first electrode rod and a second electrode rod with different diameters, and placing the first electrode rod and the second electrode rod on the outside of the pad and the outside of the remaining plates, respectively, specifically includes: Select an electrode with a diameter of 8 mm and an end spherical radius of 200 mm as the first electrode rod, and select an electrode with a diameter of 16 mm and an end spherical radius of 200 mm as the second electrode rod. Place the first electrode rod and the second electrode rod on the outside of the pad and the outside of the remaining plates, respectively.

8. The welding method according to claim 1, characterized in that, The step of setting welding parameters based on the thickness parameters of the plates and welding at least two plates according to the welding parameters specifically includes: Based on the thickness parameters of the thinner of the two outermost plates, the weld spacing, weld-to-edge distance, welding current, welding time, cooling time, pulse count, holding time, and electrode pressure are set, and at least two plates are welded using the first electrode rod and the second electrode rod with preset welding current, welding time, cooling time, pulse count, holding time, and electrode pressure.

9. A welding system, characterized in that, To perform the welding method as described in any one of claims 1 to 8, comprising: Central control unit; The coating unit, electrically connected to the central control unit, is used to form a conductive silver base layer on one side of the thinnest sheet material. The adhesive application unit, electrically connected to the central control unit, is used to apply adhesive to the other side of the thinnest sheet material. The mounting unit is electrically connected to the central control unit and is used to attach a pad to the outer surface of the conductive silver base layer. The parameter setting unit is electrically connected to the central control unit and is used to set welding parameters based on the thickness parameters of the plate. The first electrode rod and the second electrode rod are electrically connected to the central control unit, respectively, and are used to weld at least two plates on the outside of the pad and the outside of the remaining plates.

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