1 Overview The Cheng Li brand series suction truck is modified from Dongfeng brand and other types of chassis. It is mainly equipped with special facilities such as tanks, transmission systems, vacuum pumps, vacuum piping systems and suction hoses. The use of vacuum technology to carry out suction operations can cleanly and quickly transport waste and domestic sewage from septic tanks in public toilets, residential buildings, etc., to manure storage sites , or sewage treatment sites, and can also be used to remove hazardous materials if necessary. Small (such as low corrosion and low toxicity) industrial waste, is a sanitation special vehicle for the city's sanitation department, enterprises and institutions dedicated to sanitation.  The fecal vehicle is suitable for use when the material is at or above 0 °C.                                       2 working principle: (see Figure 1) Discharge process: the siphon mouth close to the bottom of the tank, change the vent direction of the four-way valve, so that the vacuum pump to the tank gas, the pressure rise in the tank, above atmospheric pressure, fecal fluid under the action of compressed air, through the siphon, suction hose Drain the tank and complete the discharge operation. 3 main structure and function The main components of the suction truck are tanks, vacuum pumps, power take-off devices, four-way valves, water and gas separators, oil and gas separators, oil storage tanks, balance arms, and anti-overflow valves. 3.1 Cans The tank body is the main body of the suction truck, and the top of it is equipped with a manhole cover, an air hole, and a suction hole. The manhole cover is normally sealed and only opened during maintenance. The air hole communicates with the steam separator through the trachea and is the passage for the air entering and leaving the tank. Suction pipe is connected with suction pipe, and it is connected with siphon pipe. It is the passage of manure fluid into and out of the tank body. The partition can reduce the damage caused by the liquid shock and vibration to the tank body and the frame connecting parts when the vehicle is running. The rear head is equipped with a sight glass, which is convenient for observing the load and preventing the liquid level from being excessively high. The lower part of the tank body is further provided with a valve, and the lower part of the tank body is welded with a lower frame. A buffer cushion is arranged between the lower frame of the tank body and the frame, and the lower frame of the tank body and the frame are fastened with bolts. 3.2 Power take-off The power of the engine drives the operation of the Home Pump through the power take-off and the drive shaft. The power take-off is mounted on the right side of the transmission. The upper part of the handle is located in the middle of the cab. The power take-off consists of an input gear, an intermediate gear, an output gear, a gear shaft, a fork shaft, a shift fork, and a handle. The input gear is in constant mesh with the transmission output gear. Before starting the vacuum pump, the transmission should be hung into neutral, then the engine is started, the clutch is disengaged, and the power take off switch is turned on. At this time, the fork shaft is moved forward and the power is transmitted from the transmission output gear to the power takeoff input gear through the middle. The gears are transmitted to the output gears, which are then transmitted by the gear shafts to the drive shafts via the couplings, thus driving the vacuum pump to operate. 3.3 vacuum pump    The suction truck uses an XD - 70 vacuum pump. When the vacuum pump is in operation, the air in the tank is drawn through the air piping system, and the liquid such as excrement and sewage is sucked and pumped. The XD - 70 rotary vane vacuum pump is an advanced product that has been improved with high vacuum, low noise and long service life. Widely used in the sanitation department's sewage equipment. 3.4 Four-way valve The vacuum pump can only rotate counterclockwise (looking at the front of the car). To draw air from the tank or to inject air into the tank, use a four-way valve to control it. The four-way valve communicates with the tank, the vacuum pump, the storage tank and the atmosphere. Operate the four-way valve handle and change the position of the channel to change the suction direction of the vacuum pump. When the four-way valve handle is perpendicular to the ground, the air in the tank is drawn through the trachea, moisture separator, and vacuum pump to perform manure absorption operation. (See Figure 1 ) 3.5 moisture separator The hydro-gas separator was preceded by an oil-gas separator, which was connected to the tank via the trachea (see Figure 1 ). Its interior is equipped with a gas pipe, which has rectangular holes on both sides for air into and out of the tank body. During the suction operation, the air in the tank comes out of the rectangular hole and suddenly expands in volume. The flow velocity decreases. A part of the water molecules with a greater degree of moisture adheres to the wall, condenses into water droplets and flows into the bottom, while the less severe gas continues to flow. Vacuum pump to achieve water and gas separation. After the separation of water and gas, the humidity of the air drops, which can reduce the damage to the lubricating oil and machinery. 3.6 , oil and gas separator The air discharged from the vacuum pump has a certain pressure and a high speed, and carries a large amount of oil droplets when breaking through the oil film layer. In order to reduce fuel consumption and prevent pollution, an oil separator was installed. The oil-gas separator is connected to a vacuum pump before the trachea, and then it passes through the storage tank. The oil separator is provided inside the oil separator. When the compressed air enters, its volume suddenly expands, the flow rate decreases, the flow direction changes, and flows out through the porous oil retaining pipe. As the velocity of oil and gas molecules decreases, the impact on the walls and walls of the hole is intensified. A part of the heavy oil molecules adheres to the wall. After the condensation, oil droplets are formed. The cistern wall and the return oil pipe flow into the oil storage tank and undergo initial purification. Air flows over the reservoir (see Figure 1 ) 3.7 , storage tank One end of the oil storage tank (or secondary oil-gas separator) is connected to an oil separator, and the other end is connected to a four-way valve (see Figure 1 ). The oil storage tank has the function of oil and gas separation and oil storage. Connected, the compressed air flowing from the oil separator must pass through multiple obstacles before it can be discharged to the four-way valve. As the volume of the oil storage tank suddenly increases exponentially, the air flow rate is significantly reduced, and other obstacles such as blocking the oil are added to the compressed air. The oil molecules intensify the collision, adhering to the inner wall and the net surface, and then flowing into the bottom, and the compressed air that has been purified again flows to the four-way valve. There is a direct-flow cock at the bottom of the tank to control the amount of lubricating oil supplied to the vacuum pump. A level tube is also provided to observe the oil storage and oil quality. The oil level in the storage tank should be in the middle or slightly lower than the middle of the level tube. Excessive oil supply will affect the oil and gas separation effect and increase fuel consumption. If the oil level is too low, the cooling will be affected and the vacuum pump will heat up too quickly. The size of the oil supply is controlled by a straight plug. The handle is fully open when it is at right angles to the axis of the inlet pipe, and is fully closed when parallel. When checking that the oil mist is evident at the outlet of the four-way valve, the fuel supply should be reduced. 3.8 Balance arm The balance arm assembly is located at the top of the tank body. It is composed of a balance seat, a connecting pipe, a counterweight block and a support frame. The front suction pipe is sucked, and the siphon pipe is connected to the rear. The balance seat can be operated. Since the counterweight block is set, The balance of work has greatly reduced the labor intensity when taking, placing, and pulling the suction hose. Qingtao support frame has holes, usually sealed, when fecal suction or siphon hose blocked openable Qingtao hole cover, Clear the blockage. 3.9 , level alarm device The liquid level alarm device is installed on the top of the tank and consists of a sensor probe, a sounder and its switches, an instrument panel and the like. The sensor probe is located in the front of the tank, 100mm from the top , insulated from the tank. The sounder and its switch are fixed on the dashboard and installed in the cab. When working, the power is turned on. When the liquid in the tank is continuously increasing, the liquid level alarm circuit is automatically turned on when the liquid level is immersed in the sensor probe, and the siren immediately emits light and sound, and the driver is notified of the information that “the amount of suction is in placeâ€. 4 , use and operation 4.1 . Pre-operation inspection 4.1.1 Check for no leakage or oil leakage. 4.1.2 Check the amount of oil in the storage tank. The amount of oil storage is in the middle or slightly below the level tube. 4.2 . Preparation before Operation 4.2.1 Keep the back of the truck as close as possible to the operating point and park it. 4.2.2 Turn the return tank's straight cock to the angle of about 45 ° with the axis of the inlet pipe. Observe the oil inlet pipe and the oil flow should occur. 4.2.3 Open the side door of the walkway box and take out the suction hose so that it swings back without bending. 4.3 , suction operation 4.3.1 Insert the fecal suction hose as deep as possible into the fecal fluid to ensure that the end of the tube is at least 300 mm from the fluid surface during the operation . 4.3.2 Push the four-way valve handle perpendicular to the ground. 4.3.3 Navigate the transmission to neutral, then start the engine, disengage the clutch, pull the power take-off switch back and pull the force, and slowly engage the clutch to operate the vacuum pump. 4.3.4 Properly increase the throttle, observe the vacuum gauge, and keep the vacuum gauge reading at 53--80kpa . 4.3.5 Open the cabin tool box, pull out the alarm switch and turn it on. 4.3.6 The operator should pay attention to monitoring the situation near the inlet of the suction hose, and use a suitable tool to prevent it from getting clogged. 4.3.7 The operator can pass through the upper mirror of the rear head. When the liquid level reaches the middle of the observation mirror, the driver should be informed, and the suction hose should be quickly pulled away from the liquid surface or stopped. Under normal circumstances, the sounder will emit audible and visual signals at this time. When the driver receives the signal, it should reduce the throttle, push the power take-off switch forward and remove the gear, and the vacuum pump stops running. Press the alarm switch to cut off the power. 4.3.8 Turn the return tank straight through the cock turn plate to close parallel to the axis of the oil tank. 4.3.9 After rinsing the hose, place it back in the walkway box and secure it firmly. 4.3.10 Dung trucks leave the operation site. 4.4 . Drainage operations 4.4.1 Point the suction hose towards the manure tank. 4.4.2 Pull the four-way valve handle to parallel with the ground. 4.4.3 Repeat steps 5.3.3 . 4.4.4 After the discharge of the fecal fluid in the tank, the driver shall push the power take-off handle forward to remove the gear, and the vacuum pump will stop running. 5.3 4.4.5 repeated. 8, section 5.3.9 Procedure. 4.4.6 Dung trucks leave the operation site. 5 , maintenance, repair 5.1 Routine Routine Maintenance 5.1.1 Check the oil return tank, the oil level should be in the middle of the level tube or slightly lower, oil 13 If the liquid turns white or there are obvious impurities, change the oil in time. 5.1.2 Check for oil leakage phenomenon. 5.1.3 check the vacuum pump, power take-off work is normal. 5.2 weekly routine maintenance 5.2.1 Clean the exterior of the vehicle. 5.2.2 Check and tighten the vacuum piping system and other parts of the bolt connection. 5.3  10000km maintenance     5.3.1 Clean the back tank and filter screen and remove the oil. Use 30# mechanical oil in summer and 20# mechanical oil in winter . 5.3.2 Check and tighten the vacuum piping system and other parts of the bolt connection. 5.4  24000km maintenance    5.4.1 Clean the back tank and the filter screen and remove the oil. Use 30# mechanical oil in summer and 20# mechanical oil in winter .  5.4.2 Check and tighten the vacuum piping system and other parts of the bolt connection. 5.4.3 Service Vacuum Pump     5.4.4 Replacing Power Take-off Lubricants 5.5 48000km maintenance Paul raised 6.4 5.5.1. 5.5.2 Check the working condition of the power take-off bearing and replace it if necessary.    5.5.3 Check Vacuum Pump for Adjustment 5.5.4 Maintain the tank, remove rust and paint on the surface. Truck Crane,Construction Machine,Mobile Crane Guanhai Engineering Machinery Technology Co., Ltd. , http://www.jncagesystem.com