QY8C Type One-way Hydraulic Lock

I. Product Introduction

The pilot-operated check valve is a controllable one-way hydraulic valve with a pilot port, which is the core component of a hydraulic lock. It plays an important supporting role in coal mine machinery, engineering machinery and various hydraulic auxiliary equipment. The valve body has a dedicated pilot oil circuit, which can switch between one-way locking and reverse conduction working modes. It is often paired to form a hydraulic lock to lock the position of hydraulic actuators, suitable for various equipment hydraulic cylinder pressure stabilization positioning conditions.

II. Valve Body Structure and Oil Port Principle

The standard internal components of the pilot-operated check valve include: valve seat, sealing steel ball, return spring, control plunger, and push rod. The valve body is equipped with A, B, X three standard oil ports, each with its own oil circuit function:

1. Forward A-B flow: Hydraulic oil pressure overcomes spring force, pushes open the sealing steel ball, and the medium can flow smoothly;

2. Reverse B-A flow: Without external control pressure, the spring pushes the steel ball against the valve seat, the oil circuit is locked, and the medium cannot flow in reverse;

3. Reverse conduction working condition: The X pilot port is connected to pressure control oil, the oil pressure acts on the control plunger to push the plunger forward, and the linked push rod pushes open the sealing steel ball, realizing reverse flow of the medium B-A.

III. Hydraulic Lock Composition and Basic Function

The hydraulic lock is assembled from two independent pilot-operated check valves, with the core function of locking hydraulic oil circuits and blocking internal oil flow in the circuit. Under external load, it can still maintain the hydraulic cylinder position fixed and stationary, avoiding component displacement and retraction, playing the role of oil circuit locking and positioning.

IV. Cooperative Spool Valve Linkage Working Logic

The hydraulic lock works cooperatively with the multi-way spool valve, relying on different spool valve positions to switch locking and pressure relief actions:

1. Spool valve neutral position: Dual-side pilot-operated check valves lock synchronously, hydraulic cylinder dual-side oil circuits are locked, and the cylinder body remains stationary;

2. Spool valve right position: Pressure oil enters port B, the right check valve conducts forward, synchronously the oil pressure links the control oil circuit, opening the left check valve, realizing hydraulic cylinder reversing action;

3. Spool valve left position: The oil circuit conduction logic is consistent with the spool valve right position working condition, reversely linking dual-side check valves, completing cylinder reverse reversing operation.

V. Oil Circuit Pressure Maintaining Characteristics

Conventional spool-type directional valves have internal fitting clearance, and trace medium leakage occurs during operation, which cannot meet the long-term pressure stabilization and maintaining requirements of oil circuits. After pairing with pilot-operated check valves to form a hydraulic lock, relying on the sealing structure of the steel ball against the valve seat, the closing sealing is stable, greatly reducing oil circuit medium leakage, meeting the long-term locking and pressure maintaining requirements of hydraulic circuits.

VI. Core Product Features

1. Three-port standardized design, forward automatic oil flow, reverse controllable opening, oil circuit flow control is clear;

2. Steel ball spring sealing structure, good closing fit, small oil circuit locking leakage, stable pressure maintaining and locking performance;

3. Paired to form hydraulic lock, dual-way interlocking oil circuit, balanced pressure bearing, stable hydraulic cylinder positioning;

4. Adapts to spool valve linkage control, relying on spool valve position switching locking and reversing modes, suitable for automated hydraulic circuits;

5. Compensates for spool valve pressure maintaining shortcomings, paired with directional valves, improving directional valve clearance leakage and short pressure maintaining time issues;

6. Simple and durable structure, few internal components, hydraulic impact resistant, suitable for mining and engineering heavy machinery hydraulic systems.

VII. Application Scope

Mainly used with coal mining machinery, construction engineering machinery, vehicle-mounted hydraulic outriggers, hydraulic tooling fixtures, energy storage matching hydraulic oil circuits, mostly used for oil circuit one-way cutoff, hydraulic cylinder bidirectional locking, hydraulic circuit pressure stabilization and maintaining, resisting external loads, and fixing hydraulic actuator component working positions.

VIII. Usage Precautions

1. Distinguish between working oil ports and X pilot port, match rated control oil pressure, oil pressure must meet standard for smooth steel ball pushing and reversing;

2. Regularly check steel ball and valve seat fitting surface, wear and impact will reduce sealing performance, affecting oil circuit locking and pressure maintaining effect;

3. When assembling hydraulic lock, verify installation direction of two pilot-operated check valves, matching hydraulic cylinder dual-side oil circuit connection;

4. Install filter components at oil circuit front end, isolate hard impurities, prevent impurities from sticking steel balls, causing oil circuit internal leakage;

5. Rely on spool valve position for standard operation, neutral position maintains pressure relief stability, avoid oil pressure impact damaging sealing components;

6. For long-term locking conditions, regularly verify X control oil circuit sealing, prevent control pressure leakage causing valve core accidental opening;

7. For high and low temperature conditions, select suitable springs and sealing accessories as needed, adapting to working condition temperatures, ensuring stable opening and closing actions.