Magnetic type fixing tool capable of optimizing charge distribution of corners of electrostatic spraying workpiece

Abstract

The utility model discloses a magnetic attraction type fixing tool capable of optimizing charge distribution at corners of an electrostatic spraying workpiece, which is used for electrostatic spraying of an iron workpiece and comprises a conductive module and a magnetic attraction module which are fixedly connected with each other, the distance between the working face of the conductive module and the edge or the sharp corner or the protrusion with the abnormal film thickness on the workpiece is set according to a preset adjusting scheme, and the conductive module is made of steel, iron, copper, alloy or other materials with good conductivity. According to the tool, the spraying effect can be improved, and the coating defects that sharp corner paint liquid drops vertically, edge paint films are thick and sag, and the film thickness at the protruding end is abnormal are avoided.

Description

Technical Field

[0001] The utility model relates to a tool for electrostatic spray painting of the outer surface of an iron metal material, in particular to a magnetic fixing device which can optimize the charge distribution of the edges, corners or outward protrusions of a workpiece during electrostatic spraying. Background Art

[0002] Electrostatic spraying is a commonly used method of external surface coating in manufacturing industries such as vehicles, ships, and home appliances. It has the characteristics of high paint utilization rate, good film quality, and fast operation speed.

[0003] If the curvature of the conductor surface and the electric field strength are constant, the charge distribution on the conductor surface determines that its charge surface density σ is a certain constant, that is, the so-called "uniform" distribution. However, based on the physical principle of the metal edge effect in an electric field environment, the charges on the sharp corners, sharp edges, protrusions and other parts of the workpiece in high field strength will accumulate abnormally high. These parts will attract more paint particles with opposite charges to adhere and cause local incomplete re-flow, resulting in excessive film thickness in the narrow S1 area with a width of about 10 to 20 mm from the edge, while the film thickness in the rest of the area is normal.

[0004] At present, there are usually two ways to deal with this phenomenon in electrostatic spraying operations. The first is to adjust the spray paint flow rate, but this often reduces the overall film thickness on the surface of the workpiece and reduces the overall quality of the coating; the second is to use scraping, grinding, and polishing to post-paint treatment after the coating is dry, which will inevitably cause a lot of labor, material, and energy waste, which is not conducive to large-scale assembly line batch production, and the coating scraping residue, dust, grinding paper, polishing fluid and other harmful substances generated are not conducive to environmental protection.

[0005] Based on the electric field charge distribution effect of closed and isolated objects in the electrostatic field, people have developed lightning strips and lightning rods, which can effectively adjust the charge distribution on the surface of objects in the electric field and prevent the main body of the building from being struck by lightning.

[0006] Based on this, the utility model applies this principle to the electrostatic spraying of metal workpieces, adjusts the electric field and charge distribution at the edges, corners or outward protrusions of the workpiece in the electrostatic field environment, and improves the accumulation of charged paint. In essence, it is equivalent to the outward extension of the edge, reducing the charge accumulation at the edge of the workpiece body.

[0007] Generally, the spraying workpiece has a complex shape, especially its edges, corners, protrusions, etc., which are of different sizes, shapes, and positions. This has resulted in many operational inconveniences in the traditional installation of tooling that relies on holes and gaps in the workpiece body. Considering the directional adsorption of magnetic materials to ferrous materials, the positioning and fixing of the tooling described in the utility model adopts a magnetic method.

[0008] The above is the technical background and theoretical basis for the development of this utility model. Utility Model Content

[0009] The development purpose of the utility model is to manufacture and implement a magnetic suction type fixing tool which can optimize the charge distribution at the edges, corners and protrusions of steel workpieces during electrostatic spraying, thereby improving the spraying effect and avoiding abnormal film thickness at the locations.

[0010] A magnetic fixed fixture that can optimize the charge distribution at the corners of electrostatically sprayed workpieces, used for electrostatic spraying of iron workpieces, includes a conductive module and a magnetic module that are fixedly connected to each other, wherein: the magnetic module is adsorbed on the back of the area to be optimized on the workpiece, and the distance between the working surface of the conductive module and the edge, sharp corner or protrusion with abnormal film thickness on the workpiece can be set according to the adjustment scheme described in the utility model; the conductive module is made of steel, iron, copper, alloy or other materials with good conductivity. The conductive module must have good conductivity to ensure the free flow of charge. The fixture does not need to use the process holes, process seams, etc. of the workpiece itself as an anchoring interface, but uses the magnetic attraction effect of ferromagnetism on the iron workpiece to achieve fixed installation.

[0011] A further optimized technical solution is: the conductive module is assembled in sequence from a current-carrying part, a conductive connecting part, and a conductive fixing part; or the conductive module is formed in one piece by forging, casting, or stamping; the current-carrying part, the conductive connecting part, and the conductive fixing part can be linear, hollow, or any other conductive material with supporting strength, and do not have to be a complete plate; their shapes can be rectangular, circular, triangular, etc., as long as they meet the needs of use.

[0012] The magnetic module consists of a magnetic part and connecting bolts and nuts for fixing; the magnetic part is fixed in a preset cavity of the conductive fixing part by connecting bolts and nuts; the magnetic part and the conductive fixing part can also be connected by a bayonet connection with a nested ring top folded edge, and the magnetic part and the conductive fixing part can also be connected by an oil-free, high temperature resistant adhesive with bonding strength that meets the requirements.

[0013] The magnetic attraction piece is adsorbed on the back of the area to be optimized on the workpiece; the distance between the attraction piece and the edge, sharp corner or protrusion with abnormal film thickness on the workpiece is set according to the adjustment scheme described in the utility model.

[0014] A further optimized technical solution is: the length D0 of the current-carrying part is between 2 and 200 mm, and the width H0 is between 3 and 30 mm; the length L0 of the conductive connecting part is between 5 and 100 mm, and the width or diameter D is between 2 and 50 mm; the radius R2 of the conductive fixing part is between 4 and 30 mm, and the thickness T is between 1 and 5 mm; the radius R1 of the magnetic part is between 2 and 25 mm, and the thickness T is between 1 and 5 mm; the connecting bolts and nuts are sufficient to fix the magnetic part and do not interfere with the magnetic module.

[0015] The further optimized technical solution is: the height difference H between the lead and the edge, sharp corner or protrusion of the workpiece with abnormal film thickness is controlled between 5mm and 10mm; the distance L between the lead and the edge, sharp corner or protrusion of the workpiece with abnormal film thickness can be controlled between (0.8 and 1.2) * H; the angle between the lead and the conductive connector is adjusted between 10° and 170° to meet different power connection requirements; the conductive module does not have to be connected in a right-angle configuration, but can also be arc-shaped, any curved surface or curve-shaped, and other forms that can meet the requirements of magnetic fixation and tooling conductivity.

[0016] A further optimized technical solution is: the magnetic attraction parts can be ferrite magnets, neodymium iron boron magnets, samarium cobalt magnets or hard materials with a certain magnetic attraction force, or soft synthetic magnetic materials with thermal stability of 150°C and above and a certain water and solvent resistance.

[0017] A further optimized technical solution is: the magnetic attraction part can be composed of an independent integral magnetic attraction material, or it can be composed of multiple pieces of magnetic attraction materials according to actual needs.

[0018] The working method of the utility model is to magnetically locate and install the tooling on a certain workpiece surface. Under the action of the electrostatic field, the charge on the edge of the iron workpiece is redistributed in accordance with the Gaussian principle under the electrostatic field. A large amount of charge is transferred to the lead-in parts of the tooling, thereby optimizing the charge of the parts of the workpiece that are prone to charge accumulation, such as the tip, edge and protrusion, reducing the adsorption of charged paint particles on these parts, and improving the coating quality of these parts.

[0019] The specific implementation steps are as follows:

[0020] Step 1, identify and confirm the abnormal film thickness points caused by electrostatic adsorption;

[0021] Step 2, magnetically adsorbing the tooling to the back side or a suitable position of the problematic film layer plate;

[0022] Step 3, adjusting the adsorption point of the tooling on the workpiece (6) so that the distance L between the lead-in component (1) and the edge, sharp corner or protrusion with abnormal film thickness on the workpiece is between 0.8*H and 1.6*H. The specific distance can be appropriately adjusted according to the structure of the workpiece and the state of the inner and outer surfaces;

[0023] Step 4: Adjust the width D1 value of the area as needed to analyze and determine whether it is necessary to repeatedly install multiple tooling in sections to achieve optimization of the entire area;

[0024] Step 5, cleaning the workpiece surface that may be contaminated;

[0025] Step 6, send the workpiece into the spraying area and wait for spraying;

[0026] Step 7, after spraying is completed, take out the tooling, or wait until the film layer is dry before taking out the tooling;

[0027] Step 8, clean the tooling, especially the surface of the magnetic suction module and the conductive module and the workpiece adsorption surface, to ensure good conductivity;

[0028] By adopting the above technical solution, the utility model has the following technical features or effects:

[0029] 1. The materials are widely available and easy to obtain;

[0030] Second, the tooling components are simple in structure, easy to store and install, and require little maintenance;

[0031] 3. The fixed installation of the tooling can be completed without relying on process holes or process gaps;

[0032] Fourth, the distance L between the power board and the edge, corner or protrusion of the workpiece can be adjusted to meet the optimization of the abnormal thick film layer during electrostatic spraying;

[0033] 5. It can significantly improve the film state, eliminate the phenomenon of paint dripping at sharp corners, thickening and sagging of edge paint film, and abnormal film thickness at protrusion ends;

[0034] 6. Abnormal phenomena in the membrane layer of a large area can be eliminated by repeatedly installing the tooling in sections;

[0035] The utility model is suitable for the electrostatic spraying working condition of iron workpieces. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 , Figure 2 , Figure 3 It is a side view, a stereoscopic view and an oblique view schematic diagram of a magnetic suction tooling structure of the utility model which can optimize the charge distribution at the corners of an electrostatically sprayed workpiece.

[0037] Figure 4 , Figure 5 The utility model is a working schematic diagram of the utility model acting on the sharp corner at the lower end of the left front fender of a commercial vehicle.

[0038] Figure 6 , Figure 7 The utility model is a working schematic diagram of the utility model acting on the upper corner of the rear door of a commercial vehicle.

[0039] Figure 8 The utility model is a working schematic diagram of the utility model acting on the long-distance edge of the outer protrusion of the left front wheel bag of a commercial vehicle.

[0040] Fig. 9 , Fig.10 It is a schematic diagram of an optimized adjustment scheme when the utility model is actually applied.

[0041] In the figure: 1. Electric conduction component; 2. Conductive connection component; 3. Connecting bolt and nut; 4. Magnetic attracting component; 5. Conductive fixing component; 6. Workpiece.

[0042] In the figure: S1 is the area enclosed by the edge of the workpiece with a width of 20 mm and a length of D1 close to the working surface of the tooling; the length of the electric conduction component 1 is D0 and the width is H0; the length of the conductive connection component 2 is L0 and the width (or diameter) is D; the radius of the conductive fixing component 5 is R2 and the thickness is T; the radius of the magnetic attracting component 4 is R1 and the thickness is T; the height difference H between the electric conduction component 1 and the edge or sharp corner or protruding plane of the workpiece 6 with abnormal film thickness. The distance between the electric conduction component 1 and the edge or sharp corner or protrusion of the workpiece with abnormal film thickness is L. The average net spraying film thickness of the large surface of the workpiece is d0, and the net spraying film thickness of the S1 area after spraying paint after optimizing the installation of the tooling is d1; Specific implementation mode

[0043] The present utility model will be further described in detail below with reference to the accompanying drawings and application cases.

[0044] The specifications of the conductive tooling used in the present utility model are as follows: the width D0 of the power connection board is 20 mm, and the height H0 is 15 mm; the length L0 of the conductive connection component is 30 mm, and the width D is 8 mm; the height difference H between the power connection board and the spraying plane of the workpiece is set to 8 mm.

[0045] The specific content can be combined with Fig. 9 and Fig.10 for easy understanding.

[0046] 1. Control the height difference H between the electric conduction component 1 of the conductive module and the edge or sharp corner or protrusion of the workpiece 6 with abnormal film thickness within the range of 5 - 10 mm; and adjust the distance L between the working surface of the electric conduction component 1 and the edge or sharp corner or protrusion of the workpiece 6 with abnormal film thickness within the range of (0.8 - 1.2) * H, which can balance the film thickness and eliminate problems such as sagging and dripping in the S1 area, and excessive thickness of the net spraying film layer.

[0047] 2. If the average net spraying film thickness of the large surface of the workpiece is set as d0, and the net spraying film thickness of the S1 area with a width of 20 mm and a length of D1 of the workpiece close to the tooling is d1; then the relationship between the value range of L and the net spraying film thickness d1 of the S1 area and d0 is approximately:

[0048] (1) When L < 0.7 * H, d1 < 0.9 * d0, and its net spraying film thickness is lower than the net spraying film thickness of the large surface.

[0049] (2) When 0.8 * H < L < 1.6 * H, d1 is between 0.95 * d0 and 1.05 * d0, which is consistent with the film thickness of the large surface and the non-edge part, and eliminates the edge effect. Therefore, (0.8 * H, 1.6 * H) is the preferred area for the value of L.

[0050] (3) When L>1.8*H, d1>1.2*d0; the film thickness is still too thick and there is a risk of film sagging, so it is not recommended to set this value.

[0051] 3. Due to the differences in materials and organizational structures of different workpieces, the height difference H between the power board and the workpiece spraying plane is also different. This change has an impact on the effective range of the S1 area. Assuming the width of the S1 area is D1, its relationship with D0 and H is roughly:

[0052] D1=(1.1~1.3)*D0+(2.2~2.8)*H;

[0053] 4. If the length D1 of the thick film area S1 is too long, it can be processed by repeatedly setting the tooling and stacking it. The maximum spacing between the tooling can be (1.1~1.3)*D0+(2.2~2.8)*H.

[0054] The sharp corner at the lower front end of the left fender of a commercial vehicle caused the paint to drip due to the discharge of the tip. Figure 4 and Figure 5 The following is an example of applying a magnetic tool to the lower part of the front end of the fender to eliminate excessive adsorption of paint liquid at sharp corners. The specific scheme and steps are as follows:

[0055] 1. Confirm that the paint dripping occurs below the front end of the left fender;

[0056] 2. Magnetically attach the tooling with the included angle of 90° between the lead-in component 1 and the conductive connector 2 to the back side of the front end plate 6 of the left fender;

[0057] 3. Carefully adjust the adsorption point so that the distance between the power board and the sharp corner or protrusion is 7mm, and the sharp corner is located in the central area of ​​the power board;

[0058] 4. Clean the sprayed surface of the workpiece 6 that may be contaminated during operation;

[0059] 5. Send the workpiece 6 into the spraying area for spraying;

[0060] 6. After spraying, put it into the drying room for drying. After the film layer is dry, cool it and take out the tooling;

[0061] 7. Clean the tooling, especially the surfaces of the magnetic module and the conductive module and the adsorption surface of the workpiece 6, to ensure good conductivity.

[0062] After being treated by the above method, the appearance of the tip at the lower front end of the left fender of the commercial vehicle was normal, the net spray film thickness of the S1 area and the net spray film thickness of the large surface were both 35 microns, and the original paint drips disappeared.

[0063] This is an example of magnetically attaching a tool to the upper edge of the right rear door of a commercial vehicle to optimize the edge charge distribution, improve the paint adsorption, and eliminate the dripping caused by excessive adhesion of the paint. Figure 6 and Figure 7 The specific plan and steps are as follows:

[0064] 1. Confirm that the paint dripping occurs on the upper edge of the right rear door of the commercial vehicle;

[0065] 2. Magnetically attach the tooling with an angle of 90° between the lead-in component 1 and the conductive connector 2 to the back side of the upper edge plate 6 of the right rear door of the commercial vehicle;

[0066] 3. Carefully adjust the adsorption point so that the distance between the power board and the edge is 8mm;

[0067] 4. Clean the sprayed surface of the workpiece 6 that may be contaminated during operation;

[0068] 5. Send the workpiece 6 into the spraying area for spraying;

[0069] 6. After spraying, put it into the drying room for drying. After the film layer is dry, cool it and take out the tooling;

[0070] 7. Clean the tooling, especially the surfaces of the magnetic module and the conductive module and the adsorption surface of the workpiece 6, to ensure good conductivity.

[0071] After being treated by the above method, the appearance of the upper edge of the right rear door of the commercial vehicle was normal, the net spray film thickness d1 of the S1 area and the net spray film thickness d0 of the large surface were both 38 microns, and the original paint dripping phenomenon disappeared.

[0072] This is an embodiment of magnetically adsorbing a tooling device on the outer edge of the right front wheel package of a commercial vehicle to optimize the edge charge distribution, improve the paint adsorption amount, and eliminate the sagging caused by excessive adhesion of the paint liquid. Figure 8 The specific plan and steps are as follows:

[0073] 1. Confirm that the paint dripping occurs on the outer edge of the wheel package on the right front of the commercial vehicle;

[0074] 2. Magnetically attach the tooling with an angle of 120° between the lead-in component 1 and the conductive connector 2 to the back side of the outer edge plate of the wheel package on the right front outward of the commercial vehicle;

[0075] 3. Install three fixtures in succession, with a fixture spacing of 28mm, and carefully adjust the adsorption points so that the distance between the working surface of the power board and the outer edge of the wheel package is 9mm;

[0076] 4. Clean the sprayed surface of the workpiece 6 that may be contaminated during operation;

[0077] 5. Send the workpiece 6 into the spraying area for spraying;

[0078] 6. After spraying, put it into the drying room for drying. After the film layer is dry, cool it and take out the tooling;

[0079] 7. Clean the tooling, especially the surfaces of the magnetic module and the conductive module and the adsorption surface of the workpiece 6, to ensure good conductivity.

[0080] After being treated by the above method, the outer edge of the right front wheel hub of the commercial vehicle has a normal appearance, the net spray film thickness d1 in the S1 area is between 36-38 microns, the net spray film thickness of the large surface is 37 microns, and the original paint dripping phenomenon has disappeared.

[0081] Those skilled in the art should understand that the above embodiments are merely examples of the present invention for ease of understanding and do not limit the function of the present invention. For example, the magnetic materials mentioned in the present invention are not limited to the magnetic materials used in the examples, such as soft magnetic materials, samarium cobalt magnets, etc., which still fall within the scope of protection of the method of the present invention; the adsorption methods mentioned in the embodiments of the present invention are not limited to the magnetic materials and ferrous metals in the embodiments, but also include adsorption by adhesive bonding methods such as self-adhesive bonding and electrostatic film bonding; the present invention is not limited to the welding method of the power board and the connecting rod and the integral forging method of the power board and the connecting rod mentioned in the embodiments, but is also applicable to other effective methods such as casting, screwing, and riveting.

[0082] In summary, the present invention is not limited to the above embodiments, and all technical solutions formed by equivalent replacement or equivalent replacement belong to the protection scope of the present invention. The technical features involved in the above embodiments can be combined with each other as long as they do not conflict with each other, and all fall within the protection scope of the present invention.

Claims

1. A magnetic fixture that can optimize the charge distribution of the corners of electrostatically sprayed workpieces, used for electrostatic spraying of iron workpieces, characterized by: It includes a conductive module and a magnetic module that are fixedly connected to each other, wherein: the magnetic module is adsorbed on the back of the workpiece area to be optimized, the distance between the working surface of the conductive module and the edge, sharp corner or protrusion with abnormal film thickness on the workpiece is set according to a preset adjustment scheme, and the conductive module is made of a material selected from steel, iron, copper and alloy.

2. The magnetic fixing tool according to claim 1, characterized in that: The conductive module is assembled in sequence from a conductive part (1), a conductive connecting part (2), and a conductive fixing part (5); or the conductive module can be integrally formed by forging, casting, or stamping; The magnetic attraction module is composed of a magnetic attraction component (4) and connecting bolts and nuts (3) for fixing; the magnetic attraction component (4) is fixed in a cavity preset in the conductive fixing component (5) by means of the connecting bolts and nuts (3); and the magnetic attraction component (4) is adsorbed on the back side of the area to be optimized of the workpiece.

3. The magnetic fixing tool according to claim 2 is characterized in that: The length D0 of the lead (1) is between 2 and 200 mm, and the width H0 is between 3 and 30 mm; the length L0 of the conductive connecting member (2) is between 5 and 100 mm, and the width or diameter D is between 2 and 50 mm; the radius R2 of the conductive fixing member (5) is between 4 and 30 mm, and the thickness T is between 1 and 5 mm; the radius R1 of the magnetic attraction member (4) is between 2 and 25 mm, and the thickness T is between 1 and 5 mm; the connecting bolts and nuts (3) are sufficient to fix the magnetic attraction member and do not interfere with the magnetic attraction module.

4. The magnetic fixing tool according to claim 2, characterized in that: The height difference H between the lead-in component (1) and the plane of the edge, sharp corner or protrusion with abnormal film thickness on the workpiece (6) is controlled to be between 5 mm and 10 mm; the distance L between the lead-in component (1) and the edge, sharp corner or protrusion with abnormal film thickness on the workpiece can be controlled to be between (0.8 and 1.2)*H; and the angle between the lead-in component (1) and the conductive connecting component (2) is adjusted between 10° and 170°.

5. The magnetic fixing tool according to claim 2, characterized in that: The magnetic attraction member (4) is one of a ferrite magnet, a neodymium iron boron magnet, a samarium cobalt magnet, or a soft synthetic magnetic material having a thermal stability of 150° C. or above and a certain degree of water resistance and solvent resistance.

6. The magnetic fixing tool according to claim 2, characterized in that: The magnetic attraction member (4) is composed of an independent integral magnetic attraction material, or is composed of a plurality of pieces of magnetic attraction material assembled according to actual needs.

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