The glue filling technology of diesel engine mainly includes cementation joint type design, surface treatment, dispensing, gluing and curing.
(L) adhesive head type design. Whether the selection of joint type is appropriate or not, it has a very important effect on the effect of adhesive bonding. Design joint should try to increase the adhesive area as far as possible. In general, the adhesive joint can be designed to withstand shear stress as far as possible to prevent the peeling, bending and unevenly pulling out of the adhesive layer. The joint type is generally butted, There are 5 kinds of joint, angle connection, T shape and tube connection.
For the workpieces with greater force or more complex force, the auxiliary measures should be taken to enhance the physical and mechanical properties of the adhesive layer. The commonly used measures, including fabric layer and metal mesh, are embedded in inserts, swallowtail grooves, pipe sleeves, core rods, screw sleeves, screws and pins, additional studs and metal buckles, additional steel plates and spot welding of adhesive parts.
(2) surface treatment of the workpiece. The purpose of surface treatment is to remove oil pollution, rust and moisture on the surface of the workpiece, and make the surface of the workpiece a certain degree of roughness and active chemical structure. There are many methods of surface treatment. The surface treatment should be made as simple as possible, small toxicity, safety and low cost. The edge of the adhesive surface is 40~60 millimeters large. In addition, for the cracked workpiece, the crack terminal should be drilling and stopping the crack, the diameter of the stop crack is 2~4 millimeters; the cross section of the crack and hole should be opened on the slope, the groove depth is 1/3 to l/2. of the workpiece thickness.
The chemical removal of oil is usually alkaline mixture, thoroughly cleaning. At present, the cleaning agent can be cleaned with metal cleaning agent, but the cleaning agent should be cleaned thoroughly with clean water after washing, remove the residual alkaline solution, and also use weak acid neutralization and alkaline. It is often used to clean the volatile organic solvents, such as acetone, anhydrous alcohol, and soothing water. Organic solvent cleaning is also used as the last cleaning before the work of the workpiece. For the cast iron, it should be heated to 200~270 degrees for a few hours to remove it, or to bake the adhesive part and the oxygen acetylene flame in the vicinity to remove the oil thoroughly.
To check the oil removal effect of the workpiece, the workpiece can be immersed in the water, and after taking out, it can be observed whether there is a layer of water film covered evenly in the position surface. If there is water or part of the water without water, it shows that the removal of oil is not thorough.
When mechanical derusting, it is best to use a sandblasting machine. When the compressed air with a sharp angle of 0.5 to 0.6 MPa is carried to impact the surface of the workpiece, it can not only remove rust but also make the workpiece surface have a certain roughness. When unconditional, the steel wheel, steel wire brush, copper wire brush, scraper, and sand cloth can be used to remove rust. Chemical derusting should be used. After chemical derusting, it must be cleaned fully and the acid washing time should be moderate in order to remove the rust trace without excessive corrosion. No apparent rust on the surface of aluminum and lead, without acid washing, is removed from the surface of the surface with a certain roughness in the surface of the workpiece. Now.
In order to make the adhesive surface with a certain degree of roughness and activation, the mechanical processing method is generally used to expose the matrix of the workpiece material. The commonly used methods are scraping, filing, grinding, rolling, rough planing, sand blasting and electrical discharge. The chemical treatment should be used for the workpiece with high bonding strength. Most adhesives are sensitive to water. Therefore, the drying should be thorough. The natural drying efficiency is low and the drying is not thorough. The drying or ultraviolet light bake can be used. The drying agent, such as silica gel and active carbon, can be dry for the workpiece which is not allowed to be heated and dried.
(3) dispensing glue. Single component glue can be used directly, multi component glue should be weighed strictly in proportion and evenly distributed in the shortest time. The adhesive container is suitable for metal ware utensils. The mixing rod can be made of metal, glass or bamboo wood. After the mixing, the glue should be coated immediately.
(4) glue. With a clean, dry brush, scraper, roller and other glue, the glue should be coated evenly and can be fully infiltrated on the adhesive surface. There should be no bubbles and holes in the glue layer. The glue layer is not too thick and is usually in 0.1-0.2 millimeter. After coating, the glue is dried for 15~30 minutes, and the glue will be joined together when the glue does not stick to the hand.
(5) curing. The 3 basic conditions for curing are "temperature, pressure, time". According to the curing temperature of different adhesives, the appropriate curing temperature is chosen, and the curing and heating are strictly prohibited. In order to compensate the shrinkage of the adhesive layer, the adhesive is evenly and closely fitted together, easy to escape the bubbles and require pressure 0-2 to 0.5 MPa; solidify. Depending on the type of curing agent, epoxy adhesives are usually cured at room temperature for 24~48 hours.
(6) safe production. All kinds of adhesives and raw materials should be sealed and stored. Toxic, flammable, explosive 名媛直播 should be placed in safe places and safekeeping by special persons. Operators should prepare anti-corrosion clothes, gloves, and protective glasses. Strictly prohibit smoking and diet on the spot. The worksite should be well ventilated and equipped with fire-fighting equipment.
