(Injection molding machine) Leakage of hydraulic system "Cause" and "Treatment"

Updated: 2016-10-14

First, the general leakage of injection molding machine is a common phenomenon of failure, mainly due to the liquid in the hydraulic components and piping in the flow of pressure and the gap between the components caused by leakage. In addition, the harsh working conditions will also seal the injection molding machine poor students a certain impact. Hydraulic system leakage in the event of a system pressure will not build up, hydraulic oil leakage can also cause environmental pollution, production and even produce incalculable serious consequences, the following impact on some of the factors affecting the injection molding machine hydraulic system to simply talk about Its causes and countermeasures. Second, the classification of leakage Leakage of injection molding machine hydraulic system there are two main, fixed seal leakage and leakage at the movement seal, fixed seal leak site, including the bottom of the cylinder, the joints of the joints, etc., sports seal include Cylinder piston rod parts, multi-channel stem and other parts, from the oil leakage can also be divided into external leakage and internal leakage, external leakage mainly refers to the leakage of hydraulic oil from the system to the environment, the internal leakage is due to high and low pressure side The existence of the pressure difference and seal failure and other reasons, the hydraulic oil within the system from the high pressure side to the low pressure side. Third, the reasons for the impact of leakage (a) design factors ① Seal the choice of hydraulic system reliability, to a large extent depends on the hydraulic system seal design and selection of seals, sealing the design of choice because of the irrational, sealed The choice of pieces of non-standard, in the design does not take into account the hydraulic oil and sealing material compatible type, load conditions, limit pressure, the size of the working speed, ambient temperature changes, which are directly or indirectly caused by different degrees of hydraulic System leakage, in addition, the use of injection molding machine environment with dust and impurities, so in the design to use the appropriate dust seal to prevent dust and other dirt into the system damage the seal, pollution of the oil, resulting in leakage. ② other design reasons the design to take into account the geometric accuracy of the moving surface and roughness is not comprehensive and in the design of the strength of the connection parts of the check, etc., which will cause the work of mechanical leakage. (2) manufacturing and adaptation factors ① manufacturing factors so the hydraulic components and sealing components have strict dimensional tolerances, surface treatment, surface finish and shape and position tolerance requirements. If the tolerance in the manufacturing process, such as: the cylinder piston radius, seal groove depth or width, the installation of the ring hole size tolerance or due to processing problems caused by rounded out. Itself has a burr or pits, plating, such as baked off, the seal will be deformed, scratched, crushed or pressure is not true and so the phenomenon of loss of its sealing function. Will make the part itself has a congenital leakage point, in the assembly process or the use of leakage occurred. ② assembly factors Hydraulic components in the assembly should be to eliminate the barbaric operation, if excessive force will cause deformation of parts, especially with copper rods and other beat cylinder. Sealing flange, etc .; assembly before the parts should be carefully examined, the assembly should be part of a little drunk hydraulic oil, gently press, cleaning application of diesel, especially seals, dust ring, O-ring and other rubber components, if With gasoline is easy to lose its original flexibility, thus losing the sealing function. (C) oil pollution and parts damage ① gas pollution At atmospheric pressure, hydraulic oil can dissolve about 10% of the air, in the hydraulic system under high pressure in the oil will dissolve more air or gas. Air bubbles in the oil, if the hydraulic support in the process of working in a very short period of time, the pressure between the high and low pressure will rapidly change the bubble in the high-pressure side of the bubble in the low-side burst, if the hydraulic system components Surface pitting and damage, the hydraulic oil will be high-speed components to accelerate the surface of the surface wear and tear, causing leakage. ② particulate pollution Hydraulic cylinder as some of the main components of the hydraulic system of injection molding machine, because the work of the piston rod exposed to direct contact with the environment, although the guide sleeve is equipped with dust seals and seals, but also inevitably dust, Dirt into the hydraulic system to accelerate the seals and piston rods such as scratches and wear, causing leakage, particle pollution is one of the fastest damage to hydraulic components. ③ water pollution and other factors due to the impact of moisture and other factors may make the water into the hydraulic system, the water will react with the hydraulic oil, the formation of acidic substances and sludge to reduce the hydraulic oil lubrication performance, accelerate component wear, water can cause control The valve stem of the bond occurs, so difficult to control the valve seal scratches, resulting in leakage. ④ Parts Damage Seals are made of oil-resistant rubber and other rubber compounds. They can cause leakage if they are used for a long period of time. If the part is damaged during impact, the sealing element may be scratched. Resulting in leakage. Fourth, the leakage of the main control measures Leakage caused by injection molding machine hydraulic system is the result of multi-faceted impact to the current technology and materials, in order to fundamentally eliminate the leakage of injection molding machine hydraulic system is very difficult to achieve, only From the above factors affect the hydraulic system leakage, take reasonable measures to minimize the leakage of hydraulic systems in the design and processing aspects of the impact of leakage to be fully considered an important factor in the design and sealing groove, , If not fully consider the initial impact of leakage factors, will bring incalculable future production losses, choose the correct assembly and repair methods, learn from past experience. For example, in the assembly of the ring as far as possible the use of special tools, and in the ring coated with some grease. In the hydraulic oil pollution control, we should start from the source of pollution, strengthen the control of pollution sources, but also take effective filtering measures and regular oil quality inspection, in order to effectively cut off the external factors (water, dust, particles, etc.) Hydraulic cylinder pollution, can add some protective measures. In short, the prevention and control of leakage to a comprehensive, comprehensive consideration can be effective.