The basic circuit of the hydraulic system in the hydraulic pump station

The basic circuit of the hydraulic system of the hydraulic pump station is mainly based on the performance, load, speed and movement form of the hydraulic actuators such as the pressure hole opening machine, the self-climbing hydraulic pipe cutting machine and the hydraulic mud pump or the hydraulic torque wrench. Basic hydraulic circuits can be found in hydraulic system reference books and design manuals.

Therefore, the best way to set up explosion-proof hydraulic pump station is to choose suitable basic circuit in these mature solutions and projects to meet the requirements of explosion-proof hydraulic pump hydraulic system design.

When selecting the basic circuit of the hydraulic system, we should not only ensure the performance requirements of the explosion-proof hydraulic pump station, but also consider the use of equipment with pressure opening and pipe cutting engineering in accordance with the principles of green, saving, reducing impact and so on. The selection of the basic circuit of the hydraulic system should begin with the commutator circuit and speed regulating circuit which play a decisive role in the performance of the main engine, and then consider other circuits as required.

If the hydraulic system provides lifting and pressure maintenance (such as hydraulic lifting platform, etc.), the system will always be subjected to the heavy gravity load of the platform and other actuators when working or stopping. If there is no corresponding balancing measure to balance the gravity load, the actuator of the platform equipment will slide by itself or lose control during operation, and the consequences will be very serious.

The function of the balance circuit is to keep a certain back pressure on the return oil circuit of the hydraulic actuator, which is used to balance the force of the actuator's gravity load on the hydraulic actuator. So that it will not fall down by itself due to the dead weight effect, to achieve the hydraulic system to machine tool operation of a stable and reliable control.

In a word, the hydraulic system is the power source of the equipment, but the use method and the function of the equipment are not the same, therefore, in the realization of these functions, the use of the circuit design is also different, the following brief introduction of a basic circuit function:

1. Select reversing and speed regulating schemes

The control of the motion direction and velocity of the hydraulic actuators in the explosion-proof hydraulic pump station is the core problem in the design of the hydraulic circuit.

For the medium and small flow hydraulic system of hydraulic torque wrench and hydraulic mud pump, most of them adopt various combination forms of reversing valve to realize the system's requirements of reversing; For high pressure and high flow hydraulic system, the pilot valve and plug valve are used to achieve.

And for the hydraulic system speed regulation loop, the system requires speed regulation stiffness, the loop is relatively simple, so you can use the throttle control mode, and according to the system to start the impact, the impact of temperature rise on seals and other requirements to choose the inlet, outlet or bypass throttle control. If the system requirements of high efficiency, less heat, then use volume speed regulation. The circulation mode of the loop is generally determined by the speed regulation mode. The throttle control mode usually adopts the open loop, and the volume control mostly adopts the closed cycle.

Explosion-proof hydraulic pump station commutation and speed regulation to achieve according to the purpose of the work, therefore, in consideration of the cost and hydraulic functions to achieve, in the use of hydraulic pump station equipment and purpose, the configuration of different hydraulic system circuit. Of course, you can also choose the full function of the hydraulic system, you can integrate the use of these equipment, not only the cost is higher, in the realization of a variety of functions when adjusting the various control valves are relatively cumbersome. In the use of strictly in accordance with the "Pioneer pipeline hydraulic equipment regulation" procedures to achieve functional transformation, otherwise it will cause insufficient power, pressure and flow of small and other situations, and even equipment damage.

2. Select the pressure control plan

In the explosion-proof hydraulic pump station in the process of the hydraulic system, the system is required to maintain a certain working pressure or pressure changes in a certain range, and sometimes the pressure can be multistage or stepless continuous regulation. For the throttling speed regulation loop, the oil is supplied by the quantitative pump, and the pressure required by the system is adjusted by the relief valve, and the system pressure is kept basically constant. In the volumetric speed regulating system, the variable pump is used to supply oil, and the safety valve plays the role of safety protection and limits the zUI high working pressure of the system.

If the system requires a low flow of high pressure oil, you can consider using a booster circuit instead of a high pressure hydraulic pump. When considering the problem of energy saving and heating during intermittent operation of the system, different forms of unloading circuit should be considered. If the working pressure of a branch circuit of the system needs to be lower than the pressure of the main oil source, the decompression circuit should be considered.

3. Adopt the balance loop of one-way sequence valve.

Adjust the sequence valve so that the product of the opening pressure and the acting area of the lower cavity of the hydraulic cylinder is slightly larger than the gravity of the vertical moving parts. When the piston goes down, because there is a certain back pressure on the return circuit to support the gravity load, the piston will fall steadily only when the upper part of the piston has a certain pressure. When the reversing valve is in the middle position, the piston stops moving and does not continue downwards. Here the sequence valve is also known as the balance valve.

In this balancing loop, when the sequence valve pressure adjustment is set, if the workload is smaller, the pump pressure needs to increase, which will increase the system power loss. Due to the internal leakage of the sequence valves and directional valves of the slide valve structure, it is difficult for the piston to stay in any position for a long time stably, which will cause the gravity load device to slide down. Therefore, this circuit is suitable for the situation where the working load is fixed and there is no high requirement for the locking and positioning of the cylinder piston.