Balancing valve

Abstract

A balancing valve for the engineering machine with 8-50 tons of lifting weight is composed of main valve and pilot valve. The said main valve consists of cylindrical valve body and main valve core. The said pilot valve is positioned in the main valve core. The core of pilot valve is linked to main valve core via springs. The main valve core is linked to valve body via more springs with different spriral directions and rigidities. Its advantages include correct, sensitive and reliable control, and preventing the burble dropping down of load.

Description

technical field [0001] The invention relates to a valve, in particular to the technical field of a hydraulic balance valve suitable for use in telescopic and luffing hydraulic cylinder circuits in construction machinery with a lifting weight of 8 to 50 tons. Background technique [0002] In modern engineering machinery, construction machinery and other mechanical equipment, a large number of hydraulic load-bearing systems are used, of which the balance valve is the key hydraulic component of this type of system, and its performance directly affects the performance of the whole machine. The balance valve is mainly composed of a control valve and a main valve. There are two common types: single-stage and pilot-operated. The single-stage main valve and the control valve are connected in parallel, and the pilot-operated main valve and the control valve are nested. The hydraulic balance valve of the form is assembled by the outer stack, which has a complex structure and a large v...

AI Technical Summary

Problems solved by technology

[0002] In modern engineering machinery, construction machinery and other mechanical equipment, a large number of hydraulic load-bearing systems are used, among which the balance valve is the key hydraulic component of this type of system, and its performance directly affects the performance of the whole machine. The balance valve is mainly composed of a control valve and a main valve. There are two common types: single-stage and pilot-operated. The single-stage main valve and the control valve are connected in parallel, and the pilot-operated main valve and the control valve are nested. The hydraulic balance valve in the form of outer stack is assembled with complex structure and large volume, so it is not convenient to be directly installed at the oil inlet of the oil cylinder. If the oil pipe is used to connect, the system will be more complicated, and the pipe is easy to leak oil. and rupture, which affect the reliability of the balance valve. For this reason, a new balance valve is designed, such as the application number 87202245U "Cartridge Balance Valve", which uses the main valve core to be inserted into the valve seat cavity Here, the pilot spool is inserted in the simple cavity of the main spool. Due to the simple insertion structure, the structure is compact, the volume is small and the weight is light, and it can be directly installed at the oil inlet of the cylinder or motor, but the balance The valve is still located outside the oil cylinder or motor, which will inevitably make the whole system larger. Moreover, the balance valve adopts the principle of hydraulic pressure feedback. Although the working stability is improved to a certain extent, the sensitivity decreases, and insufficient sensitivity will also affect its normal operation. In addition, the work of the control spool is controlled according to the oil inlet of the control port, and damping is set at the inlet of the control port, with a check valve in the damping, which brings unsafe factors to the brake locking function of the valve body , when the control valve is in the middle position, since the closing of the pilot valve is controlled by its spring and the control spool, if the one-way valve in the damping is closed immediately, a certain amount of hydraulic oil will be locked in the cavity of the control spool, so that the control If the valve cannot be reset and closed normally, it will inevitably affect the closing of the pilot valve, so that the hydraulic oil in the oil inlet enters the oil outlet through the pilot valve, and the brake locking function of the valve body fails.

There is also a control spool that directly controls the opening of the orifice. Due to the constant spring stiffness, when the operation changes suddenly, the dynamic and static performance is still not ideal due to the low sensitivity.

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