Motorcycle fuel tank and production line and method thereof
Patent Information
- Application Number
- CN202610787710.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-03
- Publication Date
- 2026-09-15
Smart Images
Figure CN122746737A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of motorcycle parts processing technology, and in particular to motorcycle fuel tanks and their production lines and methods. Background Technology
[0002] Currently, as a crucial component of motorcycles, the quality of motorcycle fuel tank manufacturing directly impacts the overall performance and appearance of the motorcycle. Existing motorcycle fuel tank manufacturing processes typically involve multiple stages, including sheet metal forming, welding, surface treatment, and decoration. However, these stages are often carried out independently and lack systematic integration.
[0003] Existing motorcycle fuel tank processing equipment is mostly a stand-alone operation mode. The stretching and forming, trimming and edge trimming, welding treatment, leak testing, surface spraying and decal application are all completed by different independent equipment. The workpiece needs to be frequently transferred between different equipment, resulting in low production efficiency. Moreover, multiple clamping and transfer can easily cause damage to the workpiece surface, affecting the quality of the finished product.
[0004] However, in the existing technology, there is no production method or production line that systematically integrates the complete process of motorcycle fuel tank production, from sheet metal shearing, stretching and forming, laser cutting, combined welding, roll welding, leak testing, phosphating and drying, primer spraying, conveying and drying, puttying and leveling, sanding and decal application. This results in low automation in motorcycle fuel tank production, poor process connection, and long production cycle, making it difficult to meet the needs of large-scale production. Summary of the Invention
[0005] The purpose of this invention is to provide a motorcycle fuel tank, its production line, and its production method, which solves the problems of scattered production and processing steps, poor connection between steps, low production efficiency, and poor quality consistency in the existing technology for motorcycle fuel tank production.
[0006] To achieve the above objectives, in a first aspect, the present invention provides a method for manufacturing a motorcycle fuel tank, comprising the following steps: The sheet metal is sheared and then stretched using a stretching die to form the fuel tank shell. The edges of the stretched and formed fuel tank shell are trimmed by laser cutting, and the trimmed fuel tank shell is then welded together. At the same time, the weld is flattened and polished. After assembling the inner and outer shells of the fuel tank, roll welding is performed on the joint edges of the two tanks. The rolled-welded fuel tank is then subjected to precision trimming, deburring, and edge pressing. Connect the treated oil tank to the air pump and place it in water for leak testing. Observe whether bubbles appear and check whether the air pump pressure is within the normal range. For oil tanks that pass the leak test, phosphating, drying, and primer spraying are carried out in sequence. After the primer is applied, the oil tank is placed on the conveyor line by a hanger for drying, and the dried oil tank is scraped and leveled. After the putty has been scraped, leveled, and dried, the oil tank is polished and then decorated with decals.
[0007] The step of "shearing the sheet metal and stretching the sheared sheet metal into shape using a stretching die to obtain the fuel tank shell" includes the following steps: Place the metal sheet on the shearing machine and cut it into blanks according to the preset dimensions; The sheared sheet is fed into the stretching die, and the sheet is positioned and clamped by the cooperation of the upper and lower dies. The hydraulic system of the stretching die is activated, causing the upper die to press down and stretch the sheet metal to form a tank shell with a predetermined curved shape. Demold the stretched fuel tank shell and check the surface of the shell for cracks or wrinkles.
[0008] The step of "trimming the edges of the stretched fuel tank shell using laser cutting, performing assembly welding on the trimmed fuel tank shell, and simultaneously flattening and polishing the weld" includes the following steps: The stretched and formed tank shell is fixed on the laser cutting worktable, and the edge of the shell is trimmed and removed by the laser cutting head along the preset trajectory to remove the process allowance. After the edges of the tank shell are cut, they are transferred to the welding station, where the edges of the shell that need to be joined are assembled and positioned. Welding equipment is used to perform combined welds on the shell joints to form a preliminary connection; The weld surface is rolled by a flattening mechanism to make the raised part of the weld flush with the shell surface. The flattened weld area is polished using polishing equipment to remove welding marks.
[0009] The section on "after assembling the inner and outer shells of the fuel tank, performing roll welding on the joint edges of the two tanks, and then sequentially trimming, deburring, and pressing the edges of the welded fuel tank" includes the following steps: The inner and outer shells of the fuel tank are pre-positioned and assembled to ensure that the mating edges of the two are aligned. The inner and outer shells are continuously rolled and welded at the joint edge by a roll welding device to form a sealed connection between the inner and outer shells. The edges of the oil tank after roll welding are precisely trimmed to remove excess material generated during the roll welding process. The burrs inside the oil tank and at the edges are ground and cleaned using an internal burr removal tool, and the edges of the oil tank are pressed and shaped using an edge pressing device.
[0010] The step of "connecting the treated oil tank to the air pump and placing it in water for leak testing, observing whether bubbles appear and checking whether the air pump pressure is within the normal range" includes the following steps: Connect the fuel tank's filler neck and pre-drilled hole to the air pump via a sealing joint; Completely immerse the fuel tank connected to the air pump in the water tank, ensuring that the surface of the fuel tank is in full contact with the water. Start the air pump to fill the oil tank with compressed air to the preset test pressure, and maintain the pressure for the set time; Observe whether bubbles are generated around the surface of the oil tank in the water tank, and at the same time monitor whether the pressure gauge reading of the air pump drops. If no bubbles are observed and the pressure gauge reading remains within the normal range, the oil tank is deemed to be in good condition.
[0011] Secondly, a production line for a motorcycle fuel tank, used in the motorcycle fuel tank production method described in the first aspect, includes a shearing module, a stretching and forming module, an edge trimming and welding module, a roll welding post-processing module, a leak testing module, a phosphating and spraying module, a drying and leveling module, and a grinding and decal module. The shearing module is used to shear the sheet material. The stretching and forming module is used to stretch and form the sheared sheet metal to obtain the tank shell; The edge trimming and welding module is used to trim and trim the edges of the stretched and formed oil tank shell, weld the trimmed oil tank shell, and flatten and polish the weld. The post-roll welding processing module is used to perform roll welding on the joint edge of the two tanks after assembling the inner shell and outer shell of the oil tank, and to perform fine trimming, deburring and pressing treatment on the rolled welded oil tank in sequence. The leak detection module is used to connect the oil tank to the air pump and place it in water for leak detection; The phosphating spraying module is used to sequentially perform phosphating treatment, drying and primer spraying on oil tanks that have passed the leak test. The drying and leveling module is used to suspend and transport the oil tank after the primer is sprayed and dry it, while scraping off the ash and leveling the dried oil tank. The grinding and decal module is used to grind and decal the oil tank after it has been scraped, leveled, and dried.
[0012] Thirdly, the motorcycle fuel tank is manufactured using the production line for motorcycle fuel tanks described in the second aspect.
[0013] The present invention discloses a method for producing a motorcycle fuel tank. A metal sheet is placed on a shearing machine and sheared to a preset unfolded size to obtain a rectangular sheet. The sheet is then fed into a stretching die, where the upper and lower dies are closed to stretch and shape the sheet, resulting in a fuel tank shell with a predetermined curved surface. The formed shell is then trimmed along a preset trajectory using a laser cutting head to remove excess material. The trimmed shell is transferred to a welding station where the butt joint is welded. After welding, the weld protrusion is pressed by a flattening mechanism, and then polishing equipment is used to remove welding marks, making the weld flush with the shell surface. Next, the inner and outer shells are pre-positioned and assembled, and the joint edges are continuously rolled welded using a roll welding device. After roll welding, the edges are trimmed, internal burrs are removed, and the edges are pressed and shaped. Finally, the fuel tank is connected to an air pump and completely submerged in a water tank. Compressed air is injected to a preset pressure and maintained. The sealing performance is determined by observing bubbles on the water surface and monitoring the pressure gauge reading. After passing the leak test, the fuel tank is immersed in a phosphating bath for chemical phosphating treatment. Once a phosphating film is formed, it is sent to a drying equipment for hot air drying, and then enters a primer spraying chamber where primer is evenly sprayed and leveled. After primer spraying, the fuel tank is suspended from the drying conveyor line via a hanging structure, and undergoes hot air curing in a drying oven during transport. The dried fuel tank is then transferred to a puttying and leveling station, where putty material is applied to the outer surface to fill depressions and pinholes, and excess material is removed. Finally, the putty-leveled and dried fuel tank is fixed to the grinding station, where coarse grinding, fine grinding, and cleaning are performed sequentially. Then, the decal pattern is aligned and applied to the predetermined position, and air bubbles are removed by pressing with a scraper to ensure firm adhesion, completing the manufacturing of the motorcycle fuel tank. Attached Figure Description
[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.
[0015] Figure 1 This is a flowchart of the manufacturing method of the motorcycle fuel tank provided by the present invention.
[0016] Figure 2 The flowchart describes the process of shearing sheet metal and then stretching the sheared sheet metal into shape using a stretching die to obtain the fuel tank shell.
[0017] Figure 3 The flowchart describes the process of trimming the edges of the stretched and formed fuel tank shell using laser cutting, performing assembly welding on the trimmed fuel tank shell, and simultaneously flattening and polishing the weld seam.
[0018] Figure 4 The flowchart describes the process of combining the inner and outer shells of the fuel tank, performing roll welding on the joint edges of the two tanks, and then sequentially trimming, deburring, and pressing the edges of the welded fuel tank.
[0019] Figure 5 The flowchart describes how to connect the treated oil tank to an air pump and place it in water for leak testing, observe whether bubbles appear, and check whether the air pump pressure is within the normal range.
[0020] Figure 6 This is a flowchart of the process of sequentially phosphating, drying, and primer spraying for oil tanks that have passed leak testing.
[0021] Figure 7 The flowchart describes the process of placing the oil tank after primer spraying onto a conveyor line for drying, and then scraping and leveling the dried oil tank.
[0022] Figure 8 This is a flowchart of the process of polishing the oil tank after it has been leveled and dried with putty, and then applying decals to the polished oil tank.
[0023] Figure 9 This is a schematic diagram of the production line for the motorcycle fuel tank provided by the present invention.
[0024] In the diagram: 1-Shearing module, 2-Stretching and forming module, 3-Edge cutting and welding module, 4-Roll welding post-processing module, 5-Leak testing module, 6-Phosphating and spraying module, 7-Drying and leveling module, 8-Grinding and decal module. Detailed Implementation
[0025] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.
[0026] Please see Figures 1 to 8 In a first aspect, the present invention provides a method for manufacturing a motorcycle fuel tank, comprising the following steps: S1 cuts the sheet metal and stretches the cut sheet metal into shape using a stretching die to obtain the tank shell; S11 places the metal sheet on the shearing machine and cuts it into blanks according to the preset dimensions; S12 feeds the sheared sheet into the stretching die, and the upper and lower dies work together to position and clamp the sheet. S13 activates the hydraulic system of the stretching die, causing the upper die to press down and stretch the sheet metal to form an oil tank shell with a predetermined curved shape. S14 demolds the stretched fuel tank shell and checks the surface of the shell for cracks or wrinkles.
[0027] Specifically, firstly, cold-rolled or galvanized steel sheets are placed on a CNC shearing machine and cut according to the preset length and width dimensions of the fuel tank's unfolded shape to obtain rectangular sheets. The sheared edges should be smooth and burr-free. Next, the sheared sheets are fed into the lower die positioning area of the stretching die. Initial positioning is achieved by the positioning pins on the lower die engaging with the positioning holes on the sheet's edges. The upper die descends and closes with the lower die, using a pressure ring to press the sheet's perimeter tightly, preventing uneven material flow during stretching. Then, the hydraulic system of the stretching die is activated, controlling the upper die to press down at a speed of 5-15 mm / s, drawing the sheet into a deep-drawn shape. This plastic deformation of the sheet under the action of the upper and lower die cavities results in a fuel tank shell with a complex curved surface. During stretching, stretching oil can be injected through the lubrication channels within the die to reduce the coefficient of friction and prevent shell breakage. After stretching is complete, the upper die moves upward to reset, and the fuel tank shell is removed from the die using a demolding mechanism. Finally, the demolded tank shell is visually inspected. Under sufficient light, the surface of the shell is visually inspected for defects such as cracks, wrinkles, and scratches. If necessary, an eddy current flaw detector is used to detect micro-cracks. Shells with defects are rejected and reworked, while qualified shells are transferred to the next laser trimming process.
[0028] S2 uses laser cutting to trim the edges of the stretched and formed fuel tank shell, and then performs a combined weld on the trimmed fuel tank shell. At the same time, the weld is flattened and polished. S21 fixes the stretched and formed tank shell onto the laser cutting worktable, and uses the laser cutting head to trim the edge of the shell along a preset trajectory to remove the process allowance; S22 transfers the trimmed tank shell to the welding station and positions the shell edges that need to be joined. S23 uses welding equipment to perform combined welds on the shell butt joints to form a preliminary connection; S24 uses a flattening mechanism to roll the weld surface, making the raised part of the weld flush with the shell surface; S25 uses polishing equipment to polish the surface of the flattened weld area to eliminate welding marks.
[0029] Specifically, firstly, the stretched and formed tank shell is fixed onto the vacuum adsorption fixture of the laser cutting worktable. The CNC system controls the laser cutting head to trim the edges of the shell along a preset three-dimensional trajectory, with the cutting speed controlled at 1-3 m / min. This removes the 3-5 mm processing allowance left during stretching and forming, ensuring the edge contour accuracy is within ±0.2 mm. Nitrogen or compressed air is used as the auxiliary gas during cutting to prevent oxidation of the cut. After trimming, the shell is transferred to the welding station. A combination fixture is used to position the edges of the two shell pieces to be joined, ensuring the butt joint gap is controlled within 0.5 mm. Subsequently, TIG or MIG welding is used to weld the shell joint, with a welding current of 80A-150A and a welding speed of 200-400 mm / min. The weld should be continuous, uniform, and free of porosity. After the weld is completed, the weld surface is rolled using a flattening mechanism with a pressure of 2-5 MPa to flatten the raised portion of the weld, controlling the height difference between it and the surrounding shell surface to within 0.1 mm. Finally, the flattened weld area is polished using polishing equipment, with the polishing grit gradually transitioning from 80# to 320# until the weld area smoothly transitions to the surrounding shell surface without obvious welding marks, thus avoiding uneven paint film thickness or appearance defects caused by weld protrusions after subsequent painting.
[0030] After S3 combines the inner and outer shells of the fuel tank, it performs roll welding on the joint edge of the two tanks, and then performs precision trimming, deburring, and edge pressing on the welded fuel tank in sequence. S31 pre-positions the inner and outer shells of the fuel tank to ensure that the mating edges of the two are aligned. S32 uses a roll welding device to continuously roll weld the joint edge of the inner and outer shells, so that the inner shell and the outer shell form a sealed connection. S33 performs fine trimming on the edges of the oil tank after roll welding to remove excess edge material generated by roll welding; S34 uses an internal burr removal tool to grind and clean the burrs on the welds and edges inside the fuel tank, and uses an edge pressing device to press and shape the edges of the fuel tank.
[0031] Specifically, firstly, the inner and outer shells of the fuel tank are pre-positioned and assembled. Using a specialized assembly fixture or positioning pins, the inner shell is fitted into the outer shell, ensuring that the mating edges are aligned circumferentially with a misalignment within 0.3mm. If necessary, conductive paste can be applied to the mating edges to improve the conductivity of the roll welding. Next, the pre-assembled fuel tank is fixed to the worktable of the roll welding device. The upper and lower rolling welding rollers of the device press against the inner and outer sides of the mating edge of the inner and outer shells, respectively. The rolling welding roller pressure is set to 1.5-3kN, the welding current to 5kA-15kA, and the rolling welding speed to 0.5-2m / min. Through continuous rolling welding, a series of overlapping weld points are formed on the mating edge, ultimately creating a continuous sealing weld, achieving a firm and sealed connection between the inner and outer shells. After the roll welding is completed, the fuel tank is transferred to the precision trimming station. Using a specialized trimming die or a CNC trimming machine, the excess edge material generated from the roll welding is precisely trimmed, removing an excess of approximately 2-4mm in width to ensure a neat edge. Next, an internal deburring tool is inserted into the fuel tank to grind and clean the burrs on the internal welds and edges, preventing them from scratching the seals or affecting fuel cleanliness during subsequent assembly. Finally, an edge-pressing device is used to shape the edges of the fuel tank, curling or flattening them to ensure the edge contour meets design dimensional requirements. This also enhances the structural strength and rigidity of the edges, preventing sharp edges from cutting personnel or assembling parts.
[0032] S4 connects the treated oil tank to the air pump and places it in water for leak testing. Observe whether bubbles appear and check whether the air pump pressure is within the normal range. S41 connects the fuel tank's filler neck and reserved channel to the air pump via a sealing joint; S42 completely submerges the fuel tank connected to the air pump in the water tank, ensuring that the surface of the fuel tank is in full contact with the water; S43 starts the air pump to fill the fuel tank with compressed air to the preset test pressure and holds the pressure for a set time; S44 Observe whether bubbles are generated around the surface of the oil tank in the water tank, and at the same time monitor whether the pressure gauge reading of the air pump drops. If no bubbles are observed and the pressure gauge reading remains within the normal range, the oil tank is deemed to be in good condition.
[0033] Specifically, first, connect the fuel tank's filler neck to the air outlet pipe of the air pump using a rubber sealing plug and quick connector. Simultaneously, seal any other pre-drilled holes on the fuel tank using corresponding sealing connectors, ensuring the entire fuel tank, except for the air filling channel, is completely sealed. Sealing tape or sealant can be wrapped around the sealing connectors and the fuel tank ports to prevent leakage of the test gas. Next, slowly lower the fuel tank, connected to the air pump, into a water tank. The water level should ensure that all welds, joints, and roll-welded areas of the fuel tank are completely submerged at least 50mm below the water surface, allowing the fuel tank surface to fully contact the water. A soft pad can be placed at the bottom of the water tank to prevent damage from impacts. Then, start the air pump to fill the fuel tank with dry compressed air, gradually increasing the inflation pressure to the preset test pressure. Once the set pressure is reached, close the inflation valve and maintain the pressure for a set time to stabilize the internal pressure of the fuel tank. During the pressure holding process, inspectors observe the surface of the oil tank through a transparent viewing window on the side of the water tank or visually to check for continuous bubbles. If continuous bubbles appear in a certain area, that area is marked as a leak point. Simultaneously, the readings of the air pump pressure gauge or independent pressure sensor are continuously monitored for a decrease. If the pressure drop does not exceed a preset threshold within the pressure holding time and no bubbles are observed, the oil tank is deemed to be airtight and can be removed, drained, and proceed to the next process. If bubbles are observed or the pressure drop exceeds the threshold, it is deemed unqualified. The oil tank is removed, the leak location is marked, and repair welding is performed. After repair, a leak test is conducted again.
[0034] S5 sequentially performs phosphating, drying, and primer spraying on oil tanks that pass the leak test. S51 immerses the leak-tested oil tank in a phosphating solution tank and performs chemical phosphating treatment on the surface of the oil tank to form a phosphating film. S52 removes the phosphated oil tank and sends it to the drying equipment, where hot air circulation dries the oil tank and removes surface moisture. S53 sends the dried oil tank into the primer spraying chamber and sprays the primer evenly onto the outer surface of the oil tank using a spray gun. S54 performs a leveling treatment on the primer layer after spraying to ensure uniform paint film thickness.
[0035] Specifically, firstly, the leak-tested and cleaned oil tank is immersed in a phosphating solution tank. The phosphating solution is zinc-based or iron-based, with the temperature controlled between 35℃ and 55℃, and the immersion time is 5-15 minutes. During the phosphating process, the phosphating solution reacts chemically with the metal surface, forming a dense phosphating film with a thickness of 1-3 μm on the inner and outer surfaces of the oil tank. This phosphating film significantly improves the adhesion of subsequent organic coatings and enhances the corrosion resistance of the oil tank. After the phosphating treatment is completed, the oil tank is lifted out of the phosphating solution tank and tilted for 30-60 seconds to allow the surface phosphating solution to flow back into the tank naturally, reducing the amount of solution carried out. Subsequently, the oil tank is sent to a phosphating drying device. The drying temperature is set at 80℃-120℃, the hot air circulation speed is 2-5 m / s, and the drying time is 10-20 minutes. The hot air circulation thoroughly removes residual moisture from the surface of the oil tank, allowing the phosphating film to solidify and dry. During the drying process, the oil tank can be suspended on a conveyor chain to ensure uniform heating of all parts. After phosphating and drying, the oil tank is sent into the primer spraying chamber, where the primer is evenly sprayed onto the outer surface of the oil tank using an automatic or robotic spray gun. The primer can be epoxy or polyurethane, with a spray thickness controlled at 15-25 μm. The spraying chamber temperature is 20℃-25℃, and the relative humidity is 50%-70%. After the primer is applied, the primer layer undergoes a leveling process. The oil tank is left to stand in the leveling chamber for 3-8 minutes to allow the solvent in the paint film to evaporate and the paint to flow naturally. This eliminates orange peel, sagging, and uneven thickness issues that occurred during spraying, resulting in a uniform paint film thickness and a smooth surface, laying a good foundation for subsequent drying and topcoat application.
[0036] S6 places the oil tank after the primer is sprayed onto the conveyor line for drying using a hanger, and then scrapes off the ash and levels the dried oil tank. S61 suspends the oil tank after primer spraying onto the hanger of the drying conveyor line via a hanging structure; S62 starts the drying conveyor line, so that the oil tank passes through the drying oven during the conveying and moving process, and uses hot air to evenly heat, dry and cure the primer. S63 removes the dried oil tank from the hanger and transfers it to the ash scraping and leveling station; S64 applies a putty material to the outer surface of the fuel tank to fill and level any minor dents, pinholes, and uneven areas. S65 performs preliminary finishing on the surface after puttying, removing excess putty material.
[0037] Specifically, firstly, the oil tank, after being sprayed and leveled with primer, is suspended from the drying conveyor line's hangers via a hook structure on its outer shell. The hangers and hook structure should fit tightly to ensure the oil tank remains stable and does not shake or fall off during subsequent conveying and drying. The spacing between the hangers is set at 400mm-800mm based on the oil tank size to avoid collisions between adjacent oil tanks. Next, the drying conveyor line is started, causing the oil tank to move through the drying oven at a speed of 0.5-2m / min. The drying oven uses circulating hot air for heating, with the temperature controlled at 120℃-160℃, and the drying time is 15-30 minutes. The hot air ensures uniform heating and curing of the primer. The continuous movement of the conveyor line ensures even heating of all parts of the oil tank within the oven, preventing localized overheating that could lead to discoloration of the paint film or insufficient drying that could result in a sticky paint film. After drying, the oil tank is moved out of the drying oven along the conveyor line and naturally cooled to below 40℃ in the cooling section. Then, the oil tank is removed from the hangers by a robotic arm or manually and transferred to the leveling and plastering station. At the putty leveling station, operators use scrapers or automatic coating equipment to apply putty material to the outer surface of the oil tank, focusing on filling and leveling minor depressions, pinholes, and uneven areas. The putty material should be applied in multiple thin coats, with each coat not exceeding 2mm in thickness to prevent cracking during drying due to excessive thickness. Finally, the surface is preliminarily finished. While the putty material is in a semi-cured state, excess putty is removed using a scraper or sandpaper to ensure a smooth surface and a seamless transition between the edges and the surrounding paint, preparing for subsequent sanding. The finished putty layer is then further dried and cured at room temperature or under an infrared drying lamp.
[0038] S7 polishes the oil tank after it has been scraped, leveled, and dried, and then applies decals to the polished oil tank.
[0039] S71 fixes the oil tank, after scraping, leveling, and drying, to the grinding station, and uses a grinding machine to roughly grind the outer surface of the oil tank; S72 performs fine grinding on the surface after coarse grinding, and cleans and removes dust from the surface of the oil tank after grinding. S73 aligns the decal pattern with the predetermined position on the surface of the fuel tank, presses the decal firmly to remove air bubbles, and ensures that the decal is firmly attached to the surface of the fuel tank.
[0040] Specifically, firstly, the oil tank, after being leveled and dried with putty, is fixed on a rotating fixture or vacuum adsorption worktable at the grinding station. The outer surface of the oil tank is then roughly ground using an electric or pneumatic grinder (such as a rail sander). This rough grinding uses sandpaper or a grinding wheel at a pressure of 0.2-0.5 MPa, focusing on removing high points, rough particles, and tool marks from the putty layer surface to achieve a basically smooth surface. During grinding, care should be taken to grind in the same or intersecting directions to avoid disordered grinding that could result in messy surface scratches. Subsequently, 240#-400# fine sandpaper is used to finely grind the surface after rough grinding, further reducing surface roughness to achieve a smooth and delicate surface with a surface roughness Ra of 0.8-1.6 μm, meeting the surface quality requirements for decal application. After fine grinding, there should be no stepped appearance from the putty layer at the edges and curved transitions. After sanding, the surface of the fuel tank is cleaned and dusted. First, use compressed air to blow away surface dust, then wipe the surface with an tack cloth or degreaser to thoroughly remove residual dust, oil stains, and impurities. This prevents these contaminants from affecting the adhesion of the decal adhesive layer, causing the decal to bubble or peel off. Next, align the pre-cut decal pattern with the predetermined position on the fuel tank surface and apply it. When applying, start from one end and gradually extend to the other end to avoid applying the entire piece at once, which can cause air bubbles. Finally, use a rubber scraper or soft roller to compact the decal, pushing it from the center outwards in a spiral or unidirectional motion to completely remove air bubbles between the decal and the paint surface, ensuring that the decal adhesive layer is in full contact with and firmly adheres to the fuel tank surface. After compaction, check whether the edges of the decal are lifted or whether there are any residual air bubbles on the surface. If necessary, make local repairs to complete the exterior decoration process of the motorcycle fuel tank.
[0041] Please see Figure 9 Secondly, a production line for a motorcycle fuel tank, used in the production method of the motorcycle fuel tank described in the first aspect, includes a shearing module 1, a stretching and forming module 2, an edge trimming and welding module 3, a roll welding post-processing module 4, a leak testing module 5, a phosphating and spraying module 6, a drying and leveling module 7, and a grinding and decal module 8. The shearing module 1 is used to shear the sheet material. The stretching and forming module 2 is used to stretch and form the sheared sheet metal to obtain the tank shell; The edge trimming and welding module 3 is used to trim and trim the edge of the stretched and formed oil tank shell, and to weld the trimmed oil tank shell. At the same time, the weld is flattened and polished. The roll welding post-processing module 4 is used to perform roll welding on the joint edge of the two tanks after combining the inner shell and the outer shell of the oil tank, and to perform fine trimming, deburring and pressing treatment on the rolled welded oil tank in sequence. The leak detection module 5 is used to connect the oil tank to the air pump and place it in water for leak detection; The phosphating spraying module 6 is used to sequentially perform phosphating treatment, drying and primer spraying on oil tanks that have passed the leak test. The drying and leveling module 7 is used to suspend and transport the oil tank after the primer is sprayed and dry it, while scraping off the ash and leveling the dried oil tank. The grinding and decal module 8 is used to grind and decal the oil tank after it has been scraped, leveled, and dried.
[0042] In this embodiment, the production line of the present invention is arranged sequentially along the production process as follows: a shearing module 1, a stretching and forming module 2, an edge trimming and welding module 3, a roll welding post-processing module 4, a leak testing module 5, a phosphating and spraying module 6, a drying and leveling module 7, and a grinding and decal module 8. The shearing module 1 is equipped with a CNC shearing machine and an automatic feeding mechanism for shearing metal sheets. The stretching and forming module 2 is equipped with a hydraulic stretching die and an automatic feeding robot for stretching and forming the sheared sheet to obtain a fuel tank shell with a predetermined curved surface shape. The edge trimming and welding module 3 is equipped with a CNC laser cutting machine, a welding robot, a rolling mechanism, and polishing equipment for trimming and finishing the edges of the stretched and formed fuel tank shell, performing combined welding on the trimmed shell, and simultaneously flattening and polishing the weld seams. The post-welding processing module 4 is equipped with a welding machine, a precision trimming mold, an internal deburring tool, and an edge pressing machine. It is used to perform welding operations on the joint edges after assembling the inner and outer shells of the oil tank, and then sequentially trim, deburr, and press the welded oil tank. The leak testing module 5 is equipped with a sealing joint, an air pump, a water tank, and a hoisting mechanism. It is used to connect the oil tank to the air pump and place it in water for leak testing. The phosphating and spraying module 6 is equipped with a phosphating solution tank, a hot air circulating drying oven, and an automatic spray gun. It is used to sequentially perform phosphating, drying, and primer spraying on oil tanks that have passed the leak test. The drying and leveling module 7 is equipped with a suspended chain drying conveyor line, hangers, and a putty leveling station. It is used to suspend and transport the primer-coated oil tank for drying, and simultaneously perform putty leveling on the dried oil tank. The sanding and decal module 8 is equipped with a sanding machine, a dust removal device, and a decal workbench. It is used to sand and decal the putty-leveled and dried oil tank. Workpieces are transferred between modules via conveyor rollers, overhead chains, or six-axis robots. Buffer zones and quality inspection points are set up between modules to form a rhythmic continuous production line, enabling large-scale and automated manufacturing of motorcycle fuel tanks.
[0043] Thirdly, the motorcycle fuel tank is manufactured using the production line for motorcycle fuel tanks described in the second aspect.
[0044] The above-disclosed embodiments are merely one or more preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art can understand that all or part of the processes for implementing the above embodiments and equivalent changes made in accordance with the claims of this application still fall within the scope of this application.
Claims
1. Method for the production of a motorcycle tank, characterized in that, Includes the following steps: The sheet metal is sheared and then stretched using a stretching die to form the fuel tank shell. The edges of the stretched and formed fuel tank shell are trimmed by laser cutting, and the trimmed fuel tank shell is then welded together. At the same time, the weld is flattened and polished. After assembling the inner and outer shells of the fuel tank, roll welding is performed on the joint edges of the two tanks. The rolled-welded fuel tank is then subjected to precision trimming, deburring, and edge pressing. Connect the treated oil tank to the air pump and place it in water for leak testing. Observe whether bubbles appear and check whether the air pump pressure is within the normal range. For oil tanks that pass the leak test, phosphating, drying, and primer spraying are carried out in sequence. After the primer is applied, the oil tank is placed on the conveyor line by a hanger for drying, and the dried oil tank is scraped and leveled. After the putty has been scraped, leveled, and dried, the oil tank is polished and then decorated with decals.
2. The method for producing a motorcycle fuel tank according to claim 1, characterized by, The process of "shearing the sheet metal and stretching the sheared sheet metal into shape using a stretching die to obtain the fuel tank shell" includes the following steps: Place the metal sheet on the shearing machine and cut it into blanks according to the preset dimensions; The sheared sheet is fed into the stretching die, and the sheet is positioned and clamped by the cooperation of the upper and lower dies. The hydraulic system of the stretching die is activated, causing the upper die to press down and stretch the sheet metal to form a tank shell with a predetermined curved shape. Demold the stretched fuel tank shell and check the surface of the shell for cracks or wrinkles.
3. The method of producing a motorcycle fuel tank according to claim 1, characterized in that, The process of "trimming the edges of the stretched fuel tank shell using laser cutting, performing assembly welding on the trimmed fuel tank shell, and simultaneously flattening and polishing the weld seam" includes the following steps: The stretched and formed tank shell is fixed on the laser cutting worktable, and the edge of the shell is trimmed and removed by the laser cutting head along the preset trajectory to remove the process allowance. After the edges of the tank shell are cut, they are transferred to the welding station, where the edges of the shell that need to be joined are assembled and positioned. Welding equipment is used to perform combined welds on the shell joints to form a preliminary connection; The weld surface is rolled by a flattening mechanism to make the raised part of the weld flush with the shell surface. The flattened weld area is polished using polishing equipment to remove welding marks.
4. The method of producing a motorcycle fuel tank according to claim 1, characterized by, The process of "after assembling the inner and outer shells of the fuel tank, performing roll welding on the joint edges of the two tanks, and then sequentially trimming, deburring, and pressing the edges of the welded fuel tank" includes the following steps: The inner and outer shells of the fuel tank are pre-positioned and assembled to ensure that the mating edges of the two are aligned. The inner and outer shells are continuously rolled and welded at the joint edge by a roll welding device to form a sealed connection between the inner and outer shells. The edges of the oil tank after roll welding are precisely trimmed to remove excess material generated during the roll welding process. The burrs inside the oil tank and at the edges are ground and cleaned using an internal burr removal tool, and the edges of the oil tank are pressed and shaped using an edge pressing device.
5. The method of producing a motorcycle fuel tank according to claim 1, characterized by, The procedure of "connecting the treated oil tank to the air pump and placing it in water for leak testing, observing whether bubbles appear and checking whether the air pump pressure is within the normal range" includes the following steps: Connect the fuel tank's filler neck and pre-drilled hole to the air pump via a sealing joint; Completely immerse the fuel tank connected to the air pump in the water tank, ensuring that the surface of the fuel tank is in full contact with the water. Start the air pump to fill the oil tank with compressed air to the preset test pressure, and maintain the pressure for the set time; Observe whether bubbles are generated around the surface of the oil tank in the water tank, and at the same time monitor whether the pressure gauge reading of the air pump drops. If no bubbles are observed and the pressure gauge reading remains within the normal range, the oil tank is deemed to be in good condition.
6. A production line for motorcycle tanks for the production method of a motorcycle tank according to any one of claims 1-5, characterized in that, It includes a shearing module, a stretching and forming module, an edge trimming and welding module, a roll welding post-processing module, a leak testing module, a phosphating and spraying module, a drying and leveling module, and a grinding and decal module; The shearing module is used to shear the sheet material. The stretching and forming module is used to stretch and form the sheared sheet metal to obtain the tank shell; The edge trimming and welding module is used to trim and trim the edges of the stretched and formed oil tank shell, weld the trimmed oil tank shell, and flatten and polish the weld. The post-roll welding processing module is used to perform roll welding on the joint edge of the two tanks after assembling the inner shell and outer shell of the oil tank, and to perform fine trimming, deburring and pressing treatment on the rolled welded oil tank in sequence. The leak detection module is used to connect the oil tank to the air pump and place it in water for leak detection; The phosphating spraying module is used to sequentially perform phosphating treatment, drying and primer spraying on oil tanks that have passed the leak test. The drying and leveling module is used to suspend and transport the oil tank after the primer is sprayed and dry it, while scraping off the ash and leveling the dried oil tank. The grinding and decal module is used to grind and decal the oil tank after it has been scraped, leveled, and dried.
7. A motorcycle fuel tank, characterized in that, The motorcycle fuel tank is manufactured using the production line described in claim 6.