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Add:B4-108, meiheng Construction Machinery City, West Outer Ring Road, Rencheng District, Jining City, Shandong Province
The cab of excavator must be painted, otherwise its metal parts will be easily corroded. Once corroded, it will bring a lot of trouble to subsequent use. So, what preparations should be made before painting? Here, professional manufacturers have given detailed answers. Come and have a look. The primer or intermediate coat shall be thoroughly polished. It is better to use 800 for excavator cab × Sandpaper or 600 × Dry grind the whole vehicle with water sandpaper, but the bare bottom cannot be polished. If there are scratches or small pits on the primer coating, the atomic ash must be made up. When making up, eye drops or very fine ash shall be made up after drying, dry grinding or water grinding. If the primer is worn accidentally and the metal bottom layer is exposed during grinding, a layer of quick drying phosphating primer shall be sprayed to ensure the anti-corrosion and anti rust ability of the substrate. Dust removal: after the grinding operation, use compressed air to completely dry the grinding dust. Dust removal shall start from the roof, and then proceed in the order of inner cavity, trunk lid, front wall, left side, back and right side. During the production line, a certain interval shall be maintained between cabs to prevent secondary pollution. Surface treatment before spraying: after dust removal, please wipe the painted body surface with a dust-free cloth to remove oil and other impurities. In the process of using dust removal cloth, it is not allowed to scrub the same part repeatedly to prevent dust from polluting the appearance of human body twice. What if there is noise in the cab of the excavator? Anti vibration. There are two kinds of vibration prevention: one is to prevent low-frequency large-scale vibration for 1-2 times, and the other is to prevent high-frequency small-scale vibration. The former can take measures to change the curvature, increase the drawbead and increase the panel stiffness. The latter can improve the damping capacity by using anti vibration materials. The common method is to add the sandwich structure of anti vibration material between the steel plates to obtain high damping capacity through the shear deformation of the middle layer, especially on the cab shell and bottom plate near the engine side. There are two ways for sandwich members: one is to add anti vibration materials between punched steel plates; Another method is to paste resin layer or asphalt based anti vibration plate on the steel plate. Appropriate elastic elements and damping elements are installed between the cab and the chassis to reduce the vibration and secondary noise of the cab structure. Sound insulation. In order to prevent the penetration of engine noise, sound insulation materials are mainly used on the inner plate near the engine side of the cab. The pores of hoses, wires and steering column passing through the cab shall be sealed around the pores to prevent sound transmission. The noise of the road surface and the noise of the engine exhaust device are mainly passed through the cab floor. Therefore, the floor should be made of double wall structure, the middle air layer can play the role of spring, and the sound insulation ability is greatly reduced. Therefore, the synthetic foam material or the skin anti vibration material should be used in the middle layer. Sound absorption. Sound absorption is the use of materials and structures that can absorb sound energy to absorb part of the sound energy in the noise propagation path, so as to reduce the noise transmitted to the operator. For engine noise, glass fiber and Mao Zhanhe foam sound absorbing materials are installed near the engine room side of the cab and inside the hood, and the sound absorption intensity and characteristics are adjusted according to the thickness and density of the material. While considering aesthetics and sound insulation, the internal materials of other internal surfaces of the cab shall have sound absorption characteristics. Sound absorbing materials are mostly porous materials, such as glass fiber, foam plastics, blankets and so on....
The excavator is most prone to high water temperature fault. Today, Xinsong shared with you the fault of high water temperature caused by water pump. How to check whether the excavator water pump works? Remove the thermostat, start the fire, run repeatedly at idle speed and high speed, press the water pipe to see if there is water passing through the water pipe. If the water pipe is hard, the pressure is normal. Then open the water tank cover and observe whether the water flow speed is normal. How to deal with water pump leakage? Open the top cover, remove the fan water stop ring, check the inside of the water pump belt, open the bottom plate of the oil pan, and confirm the specific leakage position. If the water pump oil seal and water pump cushion are damaged, they can be replaced directly. Can't the pump drain? There is no drainage on the pump. If you need to drain, you can open the drain switch under the water tank to drain. In addition, there is a drain plug (yellow) on the engine block, which can be opened to drain. How to replace the water pump? Loosen the bolt and remove the old water pump; Use a scraper to remove the dirt on the joint surface of the water pump and the cylinder block and degrease, and then apply liquid sealant on the water pump. Note: the sealant should be applied evenly without broken marks, with a width of 2-3mm. Install the water pump 20 minutes after applying the sealant, and the groove on the flange surface of the water pump should also be filled with sealant. Align the locating pin of the cylinder block and install the water pump. PS: when installing the water pump, it is recommended to use the guide bolt to prevent the dislocation of liquid sealant. The function and structure of excavator water pump is to pressurize the cooling water and make the cooling water circulate in the cooling system. Centrifugal water pump is widely used in automobile engine, which is composed of water pump shell, water pump shaft, impeller and water inlet and outlet pipes. The transmission mode of water pump is gear transmission, and the speed of water pump is 1.5 times that of diesel engine. Water pump installation and maintenance parts. Working principle when the water pump impeller rotates, the coolant in the water pump is driven by the impeller to rotate together, and is thrown to the edge of the water pump shell under the action of centrifugal force, and then is pressed into the engine water jacket through the outlet pipe on the shell which is tangent to the impeller. At the same time, the pressure in the center of impeller decreases; The cooling liquid in the radiator is sucked into the pump cavity through the water inlet pipe, so that the cooling liquid in the whole cooling system circulates....
The working principle of starting motor, starting motor is generally composed of transmission mechanism, control mechanism (electromagnetic switch) and DC motor. The working principle of the starting motor is to convert the electric energy of the battery into mechanical energy, so as to drive the flywheel on the engine to rotate, so as to realize the starting of the engine. DC motor produces electromagnetic torque, that is to say, DC motor is responsible for rotation. The transmission mechanism makes the gear driven by the starting motor mesh into the flywheel ring gear, transmits the torque of the starting motor DC motor to the engine flywheel, drives the engine crankshaft to rotate, and drives the engine components to work until the engine starts. After the engine is started, the starter is automatically disengaged from the gear ring. The electromagnetic switch is responsible for connecting and cutting off the circuit between the DC motor and the battery. According to the control mechanism, starting motor can be divided into direct control type and electromagnetic control type. Now most of our common starting motors are electromagnetic control type. The starting time of the starting motor should not be too long, generally speaking, about 10 seconds is the best. The time interval between two starts of starting motor should be about 1 minute, preferably more than 1 minute. If the engine cannot be started for three consecutive times, check the engine, battery, circuit line and wiring point. For the starting motor without over-current protection device, if it can not be started for three consecutive times, the starting motor should stop working at this time, because the starting current is too large, and it works for a long time. At this time, the starting motor will overheat due to the over current. If you continue to start the motor by force, it is very likely that the motor will burn down. After replacing the starting motor, attention should be paid to the positive and negative line contact points. It is better to polish the contact points and install them firmly. Otherwise, the engine will not start when it is hot. Starting motor maintenance, to have a good start habits, starting generally do not exceed 5 seconds, continuous start time gap of more than 15 seconds to start, the third time in a row can not start normally, after a minute to start. Do not start too long in order to avoid burning starter (that is, motor). Check the battery regularly, so that the battery can start the engine under normal capacity and power. Car starting batteries are maintenance free, and their service life is between one and a half to two years. The service life depends on the frequency of car owners. At a certain time, we must go to a professional maintenance point for inspection. Clean the engine compartment regularly to prevent dust, oil and water from corroding and aging the wiring harness of the engine compartment, so that the starter interface can not be contacted or rusted, and the electrical conductivity is not good enough to affect the normal start of the engine. It is not necessary under normal conditions. If you feel that the starter has teeth or weak start, go to the repair shop for maintenance....
In the air conditioning refrigeration system, the compressor plays the role of compressing and conveying refrigerant gas. The expansion valve plays the role of throttling and reducing pressure, and regulates the flow of refrigerant liquid into the evaporator, which is the dividing line of high and low pressure of the system. The evaporator is a kind of equipment that outputs cold air, in which the refrigerant absorbs the heat of the cooled air to cool the air. The condenser is a device to release heat. The heat absorbed by the evaporator and the heat converted by the work consumed by the compressor are emitted from the condenser and taken away by the cooling air. Air conditioning compressor is one of the main components of excavator air conditioning system. It is the conversion device of low pressure and high pressure, low temperature and high temperature in refrigeration system. The function of the compressor is to make the inlet of the compressor in a low-pressure state, so that the refrigerant carrying latent heat (including absorbing the heat in the car room) of the evaporator flows out of the evaporator. This low-pressure state can make the refrigerant enter the evaporator. The low-pressure gaseous refrigerant is compressed into the high-pressure gaseous refrigerant. These two functions of the compressor only enter the evaporator. The low-pressure gaseous refrigerant is compressed into the high-pressure gaseous refrigerant. As long as one of these two functions of the compressor fails, the refrigerant in the air conditioning system will not be able to circulate, and the air conditioning system will not work well or be able to cool. When the compressor of the air conditioning system works, the refrigerant is inhaled by the suction valve and discharged from the exhaust valve after compression. The compressors used in excavator refrigeration system can be divided into reciprocating piston type and rotary type according to their motion forms. The compressors used in excavator refrigeration system can be divided into constant displacement type and variable displacement type according to whether their working capacity changes. The variable displacement compressor can automatically change the displacement according to the refrigeration load of the air conditioning system, which makes the air conditioning system run more economically. At present, all kinds of swash plate and swing plate compressors are widely used. In recent years, swash plate and rotary compressors are mostly used, and crankshaft connecting rod compressors are rarely used, while crankshaft connecting rod compressors are still mainly used in buses. The structure of the crankshaft connecting rod compressor is similar to that of the engine. Generally, the double cylinder structure is adopted. The crankshaft rotates and drives the connecting rod to make the piston move back and forth to suck in and compress the gas. The cylinder block on the upper part of the piston is equipped with intake and exhaust valve assemblies, and a shaft seal is installed between the crankshaft and the housing to prevent refrigerant leakage. In order to ensure the normal movement of parts, the crankcase is filled with a specified amount of compressor lubricating oil and oil supply facilities. Rotary swashplate compressor, also known as swashplate compressor, is a kind of axial piston compressor. At present, it is one of the most widely used air conditioning compressors. When the piston is in the front limit position, it is the end of exhaust, and the other end of the piston is in the end of suction. When the main shaft drives the swash plate to rotate, the swash plate drives the piston to move axially, and the piston moves axially in the front and rear cylinder blocks at the same time, which is equal to two pistons moving in two directions. When the swashplate rotates for one circle, the front and rear cylinders complete a cycle respectively, which is equivalent to the work of two cylinders. Swing plate compressor, also known as swing plate (also known as one-way swash plate) compressor, is an axial piston compressor with reciprocating one-way piston structure. It belongs to the same type as swashplate, and is the most widely used type of excavator air conditioner at present. The variable displacement air conditioning compressor adopts constant meshing transmission mode, and its transmission pulley is equipped with rubber parts. The rubber parts not only play the role of transmission and vibration reduction, but also cut off the rubber parts when the air conditioning compressor is overloaded or locked, so as to avoid serious mechanical failure....
Excavator crankshaft pulley is actually a crankshaft, its role is to convert the thrust of piston connecting rod into rotary torque, so as to promote its operation. Can the excavator crankshaft pulley be disassembled? What should we pay attention to? What is its function? This is worth discussing. Generally speaking, there is a spare screw hole on the lower side of the cylinder block, which is usually close to the first cylinder and is blocked with a plug. The professional removal method is: when removing the engine crankshaft pulley, first remove the plug, put the engine disk to the top dead center of the first cylinder, screw it in from the screw hole with a special tool (similar to a long bolt, but only one section close to the bolt head has thread), and use it to hold the balance weight of the first cylinder of the crankshaft, so that the crankshaft can not rotate, Then remove it with a large torque wrench, and the pulley bolt is broken. The function of crankshaft pulley is to drive water pump, generator and air conditioning pump. Water pump is to ensure the normal operation of the engine and water circulation to achieve heat dissipation function. The generator charges the battery to ensure the normal operation of each circuit of the excavator. Air conditioning pump is a compressor used in air conditioning system. The crankshaft pulley is the power source to drive other engine accessories. It drives the generator, water pump, booster pump, compressor, etc. by means of the transmission belt. The crankshaft pulley is used to drive the camshaft, and the belt is called timing belt, which is used to connect them. As the key function of the synchronous belt transmission system, the tension wheel is used to adjust the tightness of the synchronous belt to make the transmission system stable, safe and reliable. Timing belt is an important part of engine valve system, which can ensure the accuracy of intake and exhaust time by connecting with crankshaft and a certain transmission ratio. When the engine is running, under the "timing" connection, the piston stroke (up and down movement), valve opening and closing (time) and ignition sequence (time) should always keep "synchronous" operation. Replace the crankshaft belt. When replacing the crankshaft pulley, replace the wheel first. Remove the right front wheel of the excavator. When removing the wheel, if the excavator is not supported, loosen the screw. It's easier to screw up, or it won't work. In order to ensure safety, do a good job in insurance work. The removed screws should be put in the box, which is convenient for installation and will not be missed. When you remove the tire, you will see a plastic guard. There are three plastic screws on it. Screw them off and set them aside. Remove the fixing screw in the middle of the wheel. It's very convenient to have electric tools and air guns. If you don't have a belt, don't take it off first. Turn it in one direction so that the screw will fall off. Install puller and pull out crankshaft wheel vertically. When pulling, it's better not to use the electric tool of the air gun to punch holes. If there is a deviation, you should know how much force it takes to use your hand to avoid pulling the crankshaft. Do not rush to install a new wheel after removing the pulley. Clean the oil seal on the crankshaft and the contact surface of the crankshaft. Use a flashlight to see if there is sand and rust on it. After cleaning, apply proper amount of sealant on the spline. Always clean the lip of the finger seal....
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Address：B4-108, meiheng Construction Machinery City, West Outer Ring Road, Rencheng District, Jining City, Shandong Province
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