YZCIO type series I vibratory roller hydraulic system

Tandem vibratory roller is mainly used in asphalt pavement of high grade highway and airport runway embankment engineering dry concrete compaction, because of the high grade highway and airport runway for pavement quality (such as compaction, roughness etc.) have become increasingly demanding, in order to satisfy the requirements of construction machine, roller tandem vibration need high performance. This paper analyzes the hydraulic system of YZC1O series vibratory roller developed by Sanming heavy machinery co..

L drive hydraulic system

1.1 double drive, stepless speed change

Driving pump for manual servo bidirectional variable piston pump, driven by a diesel engine through a transfer case, front and rear drive motor to provide pressure oil. The front and rear driving motors are quantitative plunger motors, and the front and rear oscillating wheels are respectively driven by a planetary reducer. 2 planetary reducers are equipped with multi disc brakes. The brake release or brake is controlled by the brake valve. When the brake is in the loose state, push the manual servo valve handle on the drive pump to drive the angle of the swash plate of the pump to change, at this time the drive pump outputs the pressure oil. Change drive pump displacement with manual servo valve swing angle changes, the maximum from the biggest to one direction in another direction, and the handle of the manual servo valve swing angle adjustable repeatedly and accurately the linear relationship.

1.2, three stage brake

A one-way valve is arranged on the shell of the hand pump, and the adjusting bolt on the shell of the hand pump is screwed clockwise, and the one-way valve is opened to form a passage, and the roller is in normal working state.

The brake valve is electrically controlled and is mounted in the circuit between the feed pump and the hand servo valve on the drive pump. When the brake valve coil is energized, the valve to the pump by manual servo brake valve and brake oil chamber oil, hydraulic thrust force will overcome the brake spring brake release, if the operating manual servo valve handle, drive pump swashplate angle changes, the output pressure of the oil pump drive, roller stepless speed change and forward or backward function; when the brake valve coil is energized, the brake oil supply is cut off and the oil chamber is communicated with the oil tank, the braking effect in the brake spring force, realize the parking brake roller.

This closed loop, when the hand servo valve handle back, drive the pump swashplate back, drive the hydraulic system of high and low pressure oil cavity to produce oil trapped, roller drive brake.

When the pressure line drive hydraulic system or other components damaged caused by brake failure or in case of an emergency, can take emergency braking measures, or press the emergency brake switch, brake valve coil power, brake braking, emergency braking the roller; the manual oil servo valve driven pump has been cut off. The swash plate back, driving pump displacement is zero, effectively protect the safety of human. YZC10 can realize three stage braking function, that is, driving brake, parking brake and emergency brake, can ensure the roller in various dynamic and static effective system.

1.3 drive and brake interlock

When the brake valve coil is energized, the parking brake roller in the state, at this time if the misoperation of manual servo valve handle, because the oil supply manual servo valve is cut off at the same time, there is no oil liquid into the driving control of servo hydraulic cylinder pump swashplate moves, swash plate drive pump will not change, drive pump no pressure oil output, realize the interlocking driving and braking, avoids roller in the brake state, pressure relief caused by misoperation of manual servo valve handle the system temperature.

1.4 short distance drag

When a fault occurs roller (engine cannot start) caused by unable to walk, on the one hand, handle the bypass valve, the bypass valve in the channel state, high and low pressure oil chamber will drive hydraulic system in communication; on the other hand counterclockwise unscrew the hand pump casing of the adjusting bolt to the one-way valve effect of cutting off the oil path brake oil cavity in the flow tank; and then manipulate the manual pump handle fuel supply to the brake oil chamber, when the pressure is increased to 2 ~ 4MPa, the brake is released. Use other traction machines to realize the short distance dragging function, and drag out the faulty road roller from the construction site, so as not to influence the construction.

When dragging after work should be restored by one-way valve and manual pump on the casing is connected to the normal working state, the brake oil chamber is communicated with the oil tank unloading braking effect, the parking brake roller.

2 vibration hydraulic system

2.1 independent vibration system of front and rear wheels

Vibration pump is double gear pump, respectively forward and backward vibration motor and steering system oil supply; vibration motor is gear motor.

The vibration system of the front and rear vibrating wheels is an independent hydraulic system, composed of vibrating pumps, vibrating motors and reversing valves. According to the needs of the working conditions, the front and rear vibrating wheels are selected to vibrate or vibrate separately, and the vibration of the vibrating wheel can be switched freely during construction.

2.2 reliable safety protection device

The electric hydraulic valve for the three position six way reversing valve, two position three way solenoid valve and the three position six way hydraulic valve, solenoid valve control hydraulic reversing valve, vibration motor forward and reverse rotation, roller system, 2 nominal amplitude and electric control, convenient operation.

The middle valve core of the reversing valve is O type. When the valve core is in the middle position, the oil outlet of the vibration pump is communicated with the oil tank, and the vibration pump is unloaded.

When the reversing back in Yan, vibration motor oil outlet blocked produce trapped oil, vibration stop immediately, the smoothness of the surface and not compaction effect of road pressure phenomenon; stop vibration, vibration of the wheel of the eccentric shaft inertia, vibration motor oil outlet for trapped oil pressure increases, when the pressure over the buffer valve set value (18.5 Mpa), a buffer opening, the system play a protective role, the oil supply valve to the oil inlet of the vibration motor to avoid cavitation in oil supply system; roller vibration, vibration rapidly increased the pressure of the hydraulic system, when the pressure exceeds the pressure relief valve the set value (17.5 Mpa), the pressure relief valve opens, protect the system limit. It provides a reliable safety protection device for vibration hydraulic system.

The relief valve, the reversing valve, the buffer valve and the oil filling valve form a reversing valve block. The valve block, vibration pump and vibration motor are all products of COM - MERCIAL - INTERTECH. The response time of overflow and buffer valve is short, the commutation is stable, the pressure shock is small, and the system reliability is high.