CN104033433A - Hydraulic control system based on single-engine road sweeper - Google Patents

Abstract

A hydraulic control system for a road sweeper based on a single engine, including a traveling hydraulic control system and a sweeping hydraulic control system; the traveling hydraulic control system includes a three-position four-way valve whose control end is connected to an accelerator pedal, and whose output end The electromagnetic floating valve is connected to the two-way variable pump, and the two-way variable pump is connected to the oil inlet and outlet of the two-way quantitative motor respectively to form a circulation loop; the cleaning hydraulic control system includes the oil tank and the transfer case arranged in parallel, and the transfer case is controlled by the opposite Controlled by two electromagnetic reversing valves, the fuel tank is connected to the transfer case through pipelines, and a hydraulic pump is installed on the connected pipelines; the sweeping motor is controlled by a separate motor electromagnetic reversing valve, and the connection between the electromagnetic reversing valve and the fuel tank Two electromagnetic reversing valves for flow diversion are arranged in parallel; an overflow valve and an unloading electromagnetic reversing valve are respectively connected between the oil tank and the transfer case. The invention reduces the auxiliary engine, does not change the driver's habit of driving the car, and saves a lot of fuel.

Description

Hydraulic Control System Based on Single Engine Road Sweeper

technical field

The invention relates to a vehicle automatic control system, in particular to a hydraulic control system for a road sweeper based on a single engine.

Background technique

As my country's urbanization process is getting faster and faster, cities are getting bigger, roads, squares, and parks are increasing, and urban cleaning and cleaning work has become more and more important and arduous. Therefore, the number of sweeping vehicles continues to increase, but the development of sweeping vehicles So far, there is no single-engine sweeper on the market, all are dual-engine models, that is, the chassis engine only provides the power of the driving system, and the auxiliary engine is responsible for providing power for the cleaning work device. When the vehicle is cleaning, the running power provided by the chassis engine only accounts for 20% to 30% of the total engine power, and the engine does not work in the best economic zone, which will inevitably lead to increased fuel consumption, increased noise, and reduced exhaust gas volume. Then it increases; while the auxiliary engine only works during the cleaning operation, its power utilization rate is also very low, and the noise of the two engines is louder at the same time, and the main engine of the cleaning vehicle runs at a low speed when it is working, and the phenomenon of "big horse and small car" appears ; At the same time, the relevant accessories and control devices required by the auxiliary engine must be configured, thereby increasing the manufacturing cost of the sweeper. At the same time, due to the global control of emissions and other reasons, in the process of meeting the requirements of Euro I to Euro IV emission regulations, the power of the chassis engine of medium-sized sweepers has gradually increased from 57kW to more than 120kW. Strict control of emission standards, if the auxiliary engine of the sweeper is required to meet Euro III or Euro IV emission standards, the manufacturing cost and fuel consumption of the sweeper will face a more severe test, so it is very important to develop a high-quality single-engine sweeper And necessary, it has very great practical significance for saving energy and improving the environment.

Contents of the invention

The object of the present invention is to provide a hydraulic control system based on a single-engine road sweeping vehicle for the above-mentioned defects in the prior art.

In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is to include a walking hydraulic control system and a cleaning hydraulic control system;

The walking hydraulic control system includes a three-position four-way valve whose control end is connected to the accelerator pedal. The output end of the three-position four-way valve is connected to a two-way variable pump through an electromagnetic floating valve. connected to form a loop;

The cleaning hydraulic control system includes a fuel tank and a transfer case arranged in parallel. The transfer case is controlled by two electromagnetic reversing valves with opposite control functions. The fuel tank and the transfer case are connected by pipelines, and A hydraulic pump with a hydraulic motor is installed on the connected pipeline; the sweeping motor is controlled by a separate motor electromagnetic reversing valve, and the first electromagnetic reversing valve and the oil tank are arranged in parallel to match with different discharge flow speed regulating valves. A split electromagnetic reversing valve and a second diverting electromagnetic reversing valve; an overflow valve and an unloading electromagnetic reversing valve are respectively connected between the fuel tank and the transfer case.

The two-way variable pump is also connected with a supplementary oil pump for auxiliary work.

A filter is arranged on the inlet pipeline of the charge pump.

The transfer case includes a suction nozzle lifting cylinder, a left sweeping disk lifting cylinder, a right sweeping disk lifting cylinder, a tipping bucket cylinder and a rear door cylinder.

On the connecting pipeline between the fuel tank and the transfer case, a hand pump is provided in parallel with the hydraulic pump to prevent the hydraulic pump from providing an emergency pressure oil source when the hydraulic pump fails to supply oil due to failure.

The hydraulic pump, the overflow valve, the unloading electromagnetic reversing valve and the transfer case, as well as the first diversion electromagnetic reversing valve, the second diversion electromagnetic reversing valve and the sweeping motor pass through the same pipeline Connect and set a pressure gauge on the connecting line.

Compared with the prior art, the present invention adds a sweeping hydraulic control system to the body chassis of the original sweeper, combined with the walking hydraulic control system, it solves the problem that the engine of the sweeper is in a non-optimal economic zone for a long time under normal working conditions . The walking hydraulic control system of the present invention adopts a circulation system composed of a two-way variable pump and a two-way quantitative motor. Since the system is a closed loop, the flow of the pump is always equal to the flow of the motor. The three-position four-way valve is directly connected to the accelerator pedal of the cab. Connected, when stepping on the accelerator pedal to change the displacement of the pump, the speed of the motor will change, so as to achieve the purpose of changing the speed of the car. The two-way variable pump can convert the mechanical energy transmitted from the engine into the hydraulic energy of the hydraulic system, and change the motor speed by changing its own displacement. The speed regulating valve plays the role of diverting flow in some occasions. When the flow divided by a certain electromagnetic reversing valve is large, the oil flowing through the sweeping motor will be very little. At this time, the sweeping motor is in the state of In the low speed stage, on the contrary, the motor is in the middle speed stage. The present invention will not change the driver's habit of driving the car, and the car can still accelerate when the gas pedal is stepped on, so that the engine is always at an economical point, that is, it is mechanically driven when high speed is required, and hydraulically driven when low speed and high torque are required during operation. On the basis of not affecting the performance of the whole vehicle, the auxiliary engine is reduced, and the exhaust emission and noise are reduced at the same time. The invention can save a large amount of fuel consumption for users, contribute a lot to the country's energy saving and emission reduction, and has epoch-making significance in the sweeping vehicle industry.

Furthermore, the closed circulation system composed of the bidirectional variable variable pump and the bidirectional quantitative motor usually has hydraulic oil leakage, and the bidirectional variable variable pump is connected with a supplementary oil pump for auxiliary work. The supplementary oil pump can replenish oil to the system to maintain an appropriate oil pressure .

Description of drawings

Fig. 1 Schematic diagram of walking hydraulic control system;

Figure 2 Schematic diagram of cleaning hydraulic control system;

In the attached drawings: 1. Charge pump; 2. Two-way variable pump; 3. Electromagnetic floating valve; 4. Three-position four-way reversing valve; 5. Two-way quantitative motor; 6. Fuel tank; 7. Hydraulic pump; 8. Hand crank Pump; 9. One-way valve; 10. Relief valve; 11. Pressure gauge; 12. Filter.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings.

Referring to Figures 1 and 2, the present invention includes a walking hydraulic control system and a cleaning hydraulic control system; the walking hydraulic control system includes a three-position four-way valve 4 whose control end is connected to the accelerator pedal, and the output end of the three-position four-way valve 4 is electromagnetically floated. The valve 3 is connected to the two-way variable pump 2, the oil outlet of the two-way variable pump 2 is connected to the oil inlet of the two-way quantitative motor 5, and the oil inlet of the two-way variable pump 2 is connected to the oil outlet of the two-way quantitative motor 5, forming a circulation loop; the two-way variable The pump 2 is also connected with a charge pump 1 for auxiliary work, and a filter 12 is arranged on the inlet pipeline of the charge pump 1; the cleaning hydraulic control system includes a fuel tank 6, and a transfer case arranged in parallel, and the transfer case includes a suction nozzle lift The oil cylinder, the left sweeping disc lift cylinder, the right sweeping disc lift cylinder, the dump bucket oil cylinder, the rear door oil cylinder, and the transfer case are all controlled by two electromagnetic reversing valves with opposite control functions. The oil tank 6 is connected to the transfer case through pipelines, and A hydraulic pump 7 with a hydraulic motor is installed on the connecting pipeline; on the connecting pipeline between the oil tank 6 and the transfer case, a device is installed in parallel with the hydraulic pump 7 with a hydraulic motor to provide emergency pressure when the hydraulic pump 7 fails to supply oil due to failure. The hand pump 8 of the oil source; the outlet pipeline of the hydraulic pump 7 and the hand pump 8 is provided with a check valve 9; the sweeping motor is controlled by a separate motor electromagnetic reversing valve DT10, The first diversion electromagnetic reversing valve DT2 and the second diversion electromagnetic reversing valve DT3 matched with different discharge flow speed regulating valves are arranged in parallel between them; the oil tank 6 and the transfer case are respectively connected with overflow valves 10 and unloading electromagnetic directional valve DT1; hydraulic pump 7, relief valve 10, unloading electromagnetic directional valve DT1 and the transfer case, and the first split electromagnetic directional valve DT2, the second split electromagnetic directional valve DT3 It is connected with the sweeping motor through the same pipeline, and a pressure gauge 11 is set on the connecting pipeline.

The working principle of the present invention is: the walking hydraulic control system includes a two-way variable pump 2, whose purpose is to convert the mechanical energy transmitted from the engine into the hydraulic energy of the hydraulic system, and can change its own displacement to change the motor speed, so as to realize the control of the vehicle. The purpose of speed regulation is the power source of the entire hydraulic system; the two-way quantitative motor 5 is the executive component of the entire chassis hydraulic system, which is used to directly drive the car; the filter 12 realizes the filtering function to provide clean oil to the charge pump 1 The advantage of this system being a closed circuit is that it can recover the kinetic energy of the hydraulic oil at the oil outlet of the hydraulic motor 5 to realize power recovery. However, there is usually hydraulic oil leakage in the closed hydraulic circuit, so a small power charge oil pump is added to the system 1. The charge pump can replenish oil to the system to maintain proper oil pressure in the system. The control end of the three-position four-way valve 4 is directly connected to the accelerator pedal, and the driver can change the flow direction and flow rate of the hydraulic oil in the three-position four-way valve 4 by stepping on the accelerator pedal. The electromagnetic floating valve 3 is floating, and the hydraulic oil generated by the three-position four-way valve 4 enters the electromagnetic floating valve to drive the variable mechanism of the variable pump, thereby realizing the change of the displacement of the variable pump and realizing the driver's control of the speed of the sweeper. control. The speed of the car is adjusted through the variable pump and quantitative motor system, which will not change the driver's habit of stepping on the accelerator to accelerate the car; this hydraulic system is not like the general hydraulic system that uses non-power recovery, and the energy generated by the system hydraulic pump is still there. A large amount of velocity flow is directly returned to the oil tank and finally converted into heat energy, which causes a waste of energy, and at the same time makes the oil heat up. The oil outlet of the hydraulic pump of the system is directly connected to the oil inlet of the motor, and the oil return port of the hydraulic pump is directly connected to the oil outlet of the motor, thus forming a closed circuit, which can recover a large amount of oil from the motor outlet. Velocity flow, thereby reducing energy loss and reducing system oil temperature. Because the system adopts a two-way variable pump and a quantitative motor mechanism, the displacement of the motor and the speed of the motor are usually constant. Since the system is a closed circuit, the flow of the pump is always equal to the flow of the motor. When we step on the accelerator pedal, it changes When the displacement of the pump is changed, the speed of the motor will change, so that the speed of the car can be changed.

Q _{pump flow} = Q _{motor flow} Q _{pump flow} = n _electric q _{pump displacement}

Q _{motor flow} = n _motor q _{motor displacement}

The motor speed and motor displacement are both fixed values, so the motor speed is a function of the variable pump displacement, so when the pump displacement is adjusted, the motor speed will change accordingly, and the pipeline system can be maintained properly through the charge pump pressure.

The hydraulic valve DT1 of the cleaning hydraulic control system is an unloading valve, which plays the role of overall discharge. When DT1 is not powered, all the oil in the oil pump 7 is directly returned to the oil tank. As long as the hydraulic system is in working condition, DT1 is powered on. (Other working conditions mentioned in the following article are not allowed to be powered, DT1 is not included) Gear pump 8 is a hand pump used to provide hydraulic oil source for the system in emergency situations, such as retracting the sweeping plate, suction nozzle, and jacking up the garbage bin that have been put down Perform maintenance work, etc. At first, DT4 is powered on, and others are not powered on. The suction nozzle lifting cylinder is lowered to prepare for work. When the gap between the rigid parts on both sides of the suction nozzle and the road surface is about 5-10mm, close DT4 and let it be in the neutral position. At this time, turn on DT6 of the left and right sweeping and lifting cylinders, and the DT8 solenoid valve will let the sweeping and lifting cylinders descend. Finish. Let the DT10 be powered on, and the others will not be powered. At this time, all the hydraulic oil of the main pump flows through the hydraulic motor to drive the motor to run at a high speed. In some occasions, DT2 and DT3 cooperate with the speed control valve behind to divert the flow of the main pump in some occasions. Because the discharge flow of the two speed control valves on the left and right is different, the discharge flow on the left is large, and the discharge flow on the right is small, so when DT3 is powered on, the flow obtained from the valve is large, so that the oil flowing through the sweeping motor is very small. less, so the sweeping motor is at a low speed at this time; when DT2 is powered on, the situation is similar to that of DT3, and the motor is at a medium speed. When the cleaning work is over, only DT10 needs to be powered off, and DT7, DT5, and DT9 are powered on for a short period of time. At this time, the sweeping lifting cylinder and suction nozzle lifting cylinder are in the return state, and then close DT7, DT9 and DT5, and operate here During the process, the excess oil overflows back to the oil tank through the overflow valve. (DT1 is blocked in the whole working condition, and the speed control valve does not participate in the working condition, as long as the driver operates the DT series, there is excess flow and when the hydraulic oil pressure exceeds 15MPa, it will overflow back to the oil tank through the overflow valve) DT11 can be powered on when the box needs to be tipped, DT12 can be powered on when the box needs to be returned; DT13 can be powered on when the back door of the garbage bin needs to be opened, and DT14 can be powered on when the back door needs to be closed; finally close DT1 realizes all unloading of hydraulic oil, so far the principle of the working hydraulic system of the road sweeper is completed.

Claims (6)

1. based on a monomotor road sweeper hydraulic control system, it is characterized in that: comprise walking hydraulic control system and sweeping fluid pressure control system;

Described walking hydraulic control system comprises the three-position four-way valve (4) that control end is connected with gas pedal, the output terminal of three-position four-way valve (4) connects two-way variable displacement pump (2) through electromagnetism floating valve (3), two-way variable displacement pump (2) is connected respectively with the oil inlet and outlet of two-way quantitative motor (5), forms circulation loop;

Described sweeping fluid pressure control system comprises fuel tank (6), and the transfer case be arrangeding in parallel, described transfer case is by two contrary solenoid directional control valve controls of control action, fuel tank (6) is connected by pipeline with transfer case, and on the pipeline connecting, is provided with the oil hydraulic pump (7) of oil hydraulic motor; Sweep table motor and controlled by independent motor solenoid directional control valve (DT10), between this solenoid directional control valve and fuel tank (6), be arranged with the first shunting solenoid directional control valve (DT2) and the second shunting solenoid directional control valve (DT3) that match with different vent flow series flow control valves in parallel; Between described fuel tank (6) and transfer case, be also connected with respectively relief valve (10) and off-load solenoid directional control valve (DT1).

2. according to claim 1 based on monomotor road sweeper hydraulic control system, it is characterized in that: described two-way variable displacement pump (2) is also connected with the slippage pump (1) for carrying out back work.

3. according to claim 2 based on monomotor road sweeper hydraulic control system, it is characterized in that: on the entrance pipe of described slippage pump (1), be provided with filter (12).

4. according to claim 1 based on monomotor road sweeper hydraulic control system, it is characterized in that: described transfer case comprises that dish hoist cylinder is swept on suction nozzle hoist cylinder, a left side, dish hoist cylinder, dump ram and back door oil cylinder are swept in the right side.

According to described in claim 1 or 4 based on monomotor road sweeper hydraulic control system, it is characterized in that: on the connecting pipeline between described fuel tank (6) and transfer case, be arrangeding in parallel to be useful on oil hydraulic pump (7) prevents that oil hydraulic pump (7) from providing the manual pump (8) of emergency pressure oil sources cannot fuel feeding time because of fault.

6. according to claim 5 based on monomotor road sweeper hydraulic control system, it is characterized in that: between described oil hydraulic pump (7), relief valve (10), off-load solenoid directional control valve (DT1) and transfer case, and first shunting solenoid directional control valve (DT2), the second shunting solenoid directional control valve (DT3) and sweep between table motor and be connected by same pipeline, and pressure gauge (11) is set on this connecting pipeline.