The purpose of cleaning parts is to remove its surface residual casting sand, iron chips, rust, abrasives, oil, dirt and other dirt. The cleanliness of the parts after cleaning will directly affect the quality of assembly and the service life of construction machinery, so the cleaning of parts is a very important link in the assembly of construction machinery. Do a good job cleaning parts, should be based on its material, structural characteristics, pollution and its cleanliness requirements, such as the correct choice of cleaning agents and cleaning methods.
Construction machinery parts oil is mainly formed by unsaponifiable oil and dust, impurities, etc.. Not saponifiable oil can not work with strong alkali, such as a variety of mineral oils, lubricants, are not soluble in water, but can be soluble in organic solvents. Removal of such oil and electrochemical two methods; commonly used cleaning solutions for organic solvents, alkaline solutions and chemical cleaning solutions, etc.; cleaning methods are manual cleaning and mechanical cleaning two.
1. Three cleaning solutions
(1) organic solvents. Common are kerosene, light diesel, gasoline, acetone, alcohol and trichloroethylene, etc.. With this dissolving method of oil removal, can dissolve a variety of grease. Advantages are no heating, easy to use, no damage to the metal, good cleaning effect. Disadvantages are mostly flammable, high cost, suitable for precision parts and parts that should not be cleaned with hot alkali solution, such as plastic, nylon, cowhide, felt parts, etc.. But need to pay attention to the rubber parts can not be cleaned with organic solvents.
(2) alkaline solution. Alkaline solution is an aqueous solution of alkali or alkaline salt, which uses emulsifiers on the non-saponifiable oil emulsification effect of oil removal, is one of the most widely used decontamination cleaning solution.
Emulsification is the formation of very small fine particles of one liquid after the uniform distribution in another liquid. Adding emulsifier in alkali solution to form emulsion can reduce the surface tension and adhesion of the oil film, so that the oil film is broken into very small oil droplets and no longer return to the metal surface to remove oil stains. Commonly used emulsifiers are soap, water glass (sodium silicate), bone gum, tree gum, triethanolamine, synthetic detergents, etc.. It should be noted that the cleaning of different materials parts should use different cleaning solutions. Alkaline solutions have different degrees of corrosion on the metal, especially for aluminum is more corrosive.
When cleaning with alkaline solution, the solution generally needs to be heated to 80~90 ℃. After oil removal, rinse with hot water to remove the surface residual alkaline solution to prevent parts from being corroded.
(3) chemical cleaning solution. Is a chemical synthesis of water-based metal cleaning agent configuration of the aqueous solution, metal cleaning agent in the surfactant-based, with strong decontamination ability. In addition, there are some auxiliary agents in the cleaning agent, can improve or increase the comprehensive performance of metal cleaners such as anti-corrosion, rust prevention, carbon removal.
The principle is the cleaning agent with cleaning solution first wet parts surface, and then penetrate the dirt and parts contact interface, so that dirt from the parts surface off, dispersion, or dissolved in the cleaning solution, or in the parts surface to form an emulsion, suspension, to achieve the purpose of cleaning parts.
Commonly configured chemical cleaning solution cleaning agents are LCX-52 water-based metal cleaner, CW metal cleaner, JSH high-efficiency metal cleaner, D-3 metal cleaner, DJ-04 metal cleaner, NJ-841 detergent, 817-C oil washing agent, CJC-8 liquid metal cleaner.
The above cleaning agent preparation method, concentration, cleaning temperature and heating measures, are required to strictly comply with the requirements of its instructions. Manual cleaning should be more strictly control the temperature, available brush, wipe cleaning. If there is serious oil or carbon, use steel wire brush. Before cleaning, it should be soaked for a certain period of time to meet the need of wetting and soaking. Cleaning can be divided into rough and fine cleaning, cleaning solution after cleaning, if the oil is not serious, you can skim off the upper layer of floating oil, and use again.
2. Five cleaning methods
(1) scrubbing. Parts into the container with diesel, kerosene or other cleaning fluid, scrubbing with cotton or brush. This method is easy to operate, simple equipment, but low efficiency, suitable for a single small batch of small parts. Generally should not use gasoline, because it has soluble fat, will damage human health and easy to cause fire.
(2) Boiling and washing. Will be configured solution and the parts to be cleaned together into the appropriate size of steel welding cleaning pool, with the pool under the stove will be heated to 80 ~ 90 ℃, boiling and washing 3 ~ 5 min can be.
(3) spray washing. Will have a certain pressure and temperature of the cleaning fluid sprayed onto the surface of the parts to remove the oil. This method of cleaning effect, high productivity, but the equipment is complex, suitable for cleaning the shape is not too complex, the surface has a serious oil scale parts.
(4) vibration cleaning. The parts to be cleaned on the vibration cleaning machine cleaning basket or cleaning rack, and submerged in the cleaning fluid, through the cleaning machine to produce vibration simulation of manual rinsing action and the chemical action of the cleaning fluid to remove the oil.
(5) ultrasonic cleaning. Rely on the chemical action of the cleaning fluid and the introduction of ultrasonic oscillation in the cleaning fluid together to remove the oil.
Note: should be based on the causes and characteristics of oil pollution reasonable choice of cleaning methods to ensure the normal use of parts, to avoid cleaning on the parts caused by corrosion or damage, to prevent pollution of the environment and the subsequent defacement of parts.
