The use of hydraulic pneumatics and seals in the Daewoo DH50 excavator Ning Tao Ding Xuegong Wang Xiu Xia type crusher performance requirements. Provides reference for installation of larger horsepower crushers on small and medium excavators. Our company was commissioned by the customer to install STANLEY's MB656 crusher on our DH50 excavator. The 50-type excavator is the smallest excavator produced by our company. Compared with other excavators of the same type, this model has the characteristics of small volume, large power, flexible operation, and comfortable driving. It is widely used in small projects and small work sites. Place. The STANLEY MB656 crusher is suitable for small and medium backhoes. Compared with the same type of shredder, it has a higher power-to-mass ratio and more stable performance. Whether the two can be matched properly is the key to successful installation. 1 Feasibility analysis 1.1 performance parameters ugly 1 variable plunger pump pressure such as = 2 pressure outside = 18MPa minimum flow 6, the optimal flow 83, 1.2 parameter analysis can be seen from the above parameters, the working pressure of a working pump type 656 crushing 2 valve; 3 accumulator; 4 confluent block; 5 one-way valve; 6 main valve group; 7, 3, type diverter valve; 8 crusher valve force can meet the requirements of breaker pressure, but any The pump wants the breaker to work properly and the pump must be confluent. The crusher interface is reserved in the hydraulic system of the DH50 excavator, which is matched with the crusher produced by Daewoo and is supplied by the pump 82 and controlled by the valve Fl. If you want to install STANLEY's MB656 crusher, you must select another pump and pump 2 confluence to meet the crusher flow requirements. From the parameters of the pump 83, the maximum flow rate 323 after the confluence with the pump 82 is slightly greater than the maximum flow rate of the crusher, so when the crusher operates, the operation of the actuator originally driven by the pump and the pump 82 must stop. In fact, in addition to the necessary adjustment of the excavator's working posture before the crusher works, it is feasible that the excavator can drive the 656 crusher with the crusher and the ugly 2 confluence. 2 transformation of the hydraulic system 2.1 The principle of the transformation of the hydraulic system can not be reconstructed the function of the original system, when the crusher stops working, the operating status of the original system can be immediately restored; and after the breaker is replaced with a bucket, normal excavation can be performed. In addition, the negative impact on the original system during crusher operation should be minimized. 2.2 Modification of the hydraulic system The output of the program 31 is increased by 30 diverter valves produced by the 3-D unit. 7. When the crusher is working, the diverter valve is mainly used to supply oil to the crusher; when the crusher stops operating, the oil supply to the original system is resumed. Specifically, 8 ports are connected to the original system, and the ports are merged with the port 1 of the valve 1 to supply oil to the crusher. Due to the severe impact on the system caused by the crusher operation, it is necessary to increase the accumulator 3 at the inlet and outlet ports of the crusher, and to increase the check valve before the confluence 5. It can be seen that the type 30 diverter valve pair To ensure the normal operation of the original system and the new system plays a key role. The working principle of the 2.3, 30 type diverter valve, 30 diverter valve is a kind of diversion valve with electromagnetic control function conversion, and has the functions of gear flow adjustment and pressure compensation. The pressure difference across the spool interacts. Since the area of ​​the spool at both ends is equal to 4, the necessary conditions for the spool balance are 1 solenoid valve; 2 spring; 3 overflow valve; 4 main spool; 5 throttle valve; 6 one-way valve; 78 variable throttle trapped 2 , 30 Diverter valve structure 2.3.1 Solenoid valve control function The switching spring chamber communicates with the inlet port of the solenoid valve through the port. When the solenoid valve is de-energized, the solenoid valve will connect the oil inlet to the oil tank. At this time, the main valve core moves to the spring side under the action of knowledge, so that the variable orifice 7 is completely opened, and the throttle orifice 8 is completely closed. At this point, pumping through the port of the diverter valve completely feeds the original system. When the solenoid valve is energized, the solenoid valve disconnects its oil inlet from the tank and communicates with the relief valve 3 setting pressure of 21 MPa. At this time, the number of nine gradually increases, and the main spool is moved toward the no-spring side, so that eight ports are gradually opened and seven ports are gradually closed. As the flow of the mouth gradually increases, the pressure drop across the orifice 5 increases, causing the nine to decrease and the fourth to gradually increase, eventually balancing with the spring force at a certain position. At this time, the IN port does not divert quantitatively to the A and 3 ports. In this way, the pump twists the metering oil through the outlet of the diverter valve. 2.3.2 Flow regulation Because the pressure difference 4 at the two ends of the main spool is mainly due to the hydraulic oil passing through the throttle valve 5, when the mouth is generated, so that you can rotate the throttle valve 5, in the mouth to produce a difference The diameter of the orifice, corresponding to the different pressure drop 4 æ² corresponding to the main spool will produce a different position and balance. At this time, the proportion of diversions at the mouth and the three mouths changes, and then different flows are generated at the mouth. In this way, the throttle valve 5 can be adjusted to obtain the optimum working flow of the breaker. 2.3.3 Pressure compensation function When the pressure of the mouth increases with the increase of the load, the flow rate of the mouth decreases due to the momentary movement of the main spool. The pressure drop of the hydraulic oil through the mouthpiece 4 is reduced, causing the main spool to move toward the no-spring side, so that the 7 ports are closed and the 8 ports are increased, so that the port flow rate is increased and the 6 port flow rate is reduced. vice versa. 3 Matters needing attention in design, installation and debugging The selection of check valve 5 should be selected according to the maximum flow rate of each pump. In order to increase the impact of the breaker, try to reduce the return pressure. First, the diameter of the return pipe should be selected according to the maximum flow rate of the crusher; in addition, the return oil of the crusher should be connected to the fuel tank separately. In order to facilitate the replacement of the bucket, a shut-off valve shall be provided at the inlet and outlet of the breaker. 4 Conclusions After the transformation, the field experiments confirmed that the entire excavator system was operating in a good condition and the breakers were balanced and reliable, achieving the expected results of the conversion. Through this modification, successful experience has been achieved in the installation of larger power breakers using small excavators. Lei Tianjue. New hydraulic engineering manual, first volume. Beijing University of Technology Publishing Author Ning Tao, male, born in August 1970, graduated from Taiyuan in 1992, graduated from the Institute of Mechanical and Electrical Engineering, Assistant Engineer, Production Technology Department of Daewoo Heavy Industry Yantai Co., Ltd., Yantai City, Shandong Province, Technical Development Zone refers to the upper page 28. The hydraulic motor in the rotary drive can be either a through-shaft type axial piston motor or a diagonal axis type axial piston motor. The latter has a small starting moment of inertia due to the rotating parts, and has a good starting characteristic and a high starting efficiency. Starting from the slewing mechanism of the excavator noon frequently, the inclined axis type axial piston motor can meet the requirements of working conditions. A rotary brake valve is also integrated on the hydraulic motor to produce a hydraulic brake. The slewing drive also has a parking brake. The planetary reducer is composed of a primary spur gear drive and a planetary gear output stage. Some small hydraulic excavator rotary hydraulic motors use low speed high torque radial piston motor. Its advantage is that no planetary speed reducer is needed, the hydraulic motor is directly connected with the swing mechanism, the structure is simplified, the efficiency is high, and the service life is long. At this time, a hydraulic brake valve must be installed on the low-speed hydraulic motor to perform hydraulic braking. 3.3 Hydraulic valves As the excavator's hydraulic system uses the double-pump dual-circuit system, the 80's used two 4-valve integral multi-way valves. In the 90's, it gradually used the group of 6 to 9 valve cores as a whole multi-way valve. The pipeline is greatly reduced, saving the time required to connect the oil circuit, and also reducing the chance of oil leakage at the pipeline connection. It is expected that multi-valve monoblock valves will be used in more and more excavators. 4 Development trend of hydraulic system and components 4.1 High-pressure high pressure can effectively improve the power transmission efficiency of the machine, make the hydraulic device compact and have greater advantages. At present, the pressure level of the excavator system with advanced technology level has been improved. Years ago 4.2 4.2 Progress and Energy Saving and Full Use of Engine Power Excavator hydraulic systems have evolved into comprehensive control systems, ranging from constant power control to constant pressure control, negative control, and pressure shutoff. The hydraulic pump's various variable forms and pressure control methods are combined to make full use of the engine power to improve the hydraulic system efficiency. 4.3 Electromechanicalization Adopts electronic direct control to achieve intelligence. Not only does the hydraulic system perform fault monitoring for condition monitoring, but more importantly it implements full electronic control of the entire excavator. Application of electronic control technology to solve the flow distribution of the pump and the multi-way valve well Q asked the power matching of the pump and the engine. 1 Wang Changjiang. Contemporary excavator requirements for hydraulic systems and development direction of hydraulic systems. Construction Machinery and Maintenance. 199712 Yang Erpi. The Status Quo and Development of Hydraulic and Pneumatic Technology in China. Hydraulic and pneumatic. Iron Nail,Pure Iron Nails,Iron For Nails,Galvanized Iron Nail HENGSHUI YUZHENG IMPORT AND EXPORT CO., LTD. , https://www.yuzhengnails.com