Rexroth 4WE6 Series Solenoid Directional Valve | 4WE6H 4WE6E | Hydraulic Control Valve

The Rexroth 4WE Series premium industrial-grade high-pressure solenoid directional control valves manufactured by Chengyuan Hydraulic are high-efficiency fluid power logic components precision-engineered to thoroughly match the technical design principles of Bosch Rexroth. This robust alternative matrix specifically addresses the demanding standards of size 6 (NG6 / Cetop 3 / ISO 4401-03) universal interface configurations widely found across automated machine tools, compact hydraulic power units, and material handling systems, featuring standard configurations like the 4WE6H-L6X/CG24NZ5L (H-spool, 24V DC with manual override), the 4WE6H-L6X/OFCG24NZ5L (with mechanical detent mechanism), and the modernized 4WE6E61B/CG24N9Z4 (E-spool all-ports-blocked configuration).

Operating as the reliable primary direction switching heart within integrated hydraulic manifold plates, branching cylinders, and rotary motor circuits, a solenoid valve’s spool centering alignment stiffness and responsiveness under continuous cyclic pressure loads determine the placement precision of the total actuator group. The 4WE6 family utilizes a wet-pin direct-acting armature framework. Chengyuan guarantees 100% original-place drop-in interchangeability across all assemblies regarding standard ISO 4401 subplate port patterns, standard DIN 43650 electrical plug junctions, micron-level spool-to-bore clearances, and magnetic solenoid tractive ratings. Prior to shipment, every single directional valve undergoes 100% full-capacity simulated continuous pressure switching, core leakage, and coil temperature saturation verification tests on digital testing rigs, ensuring continuous performance up to 31.5 MPa.

Technical Specifications 

• Compatible Brand Standard: Bosch Rexroth (Industrial Size 6 NG6 Directional Standard)

• Target Replacement Configurations: 4WE6H-L6X/CG24NZ5L, 4WE6H-L6X/OFCG24NZ5L, 4WE6E61B/CG24N9Z4

• Nominal Interface Dimension: Size 6 designation (NG6 / Cetop 3 / ISO 4401-03-02-0-05 pattern)

• Spool Control Flow Symbol Classifications:

  • H-Function (4WE6H Series): In the center neutral position, ports P, A, B, and T are fully interconnected (allowing system unloading and actuator floating).

  • E-Function (4WE6E Series): In the center neutral position, ports P, A, B, and T are completely blocked (ensuring position locking and system pressure retention).

• Maximum Allowable Continuous Operating Pressure:

  • Ports P, A, B: 31.5 MPa (315 bar / 4,568 psi)

  • Port T (Tank Line): 21.0 MPa (210 bar / 3,045 psi max. allowable dynamic backpressure for DC coils)

• Maximum Flow Capacity: Up to 80 L/min (21 USgpm), governed by chosen spool type and pressure-drop performance limits.

• Actuation Coil Voltage Identification: Code G24 specifies a heavy-duty 24V Direct Current (24V DC) solenoid core, paired with a standard large square DIN 43650 connection socket (Z5L) equipped with an integrated LED indicator light.

• Functional Modifiers Breakdown:

  • L6X Code: 6X universal product design sequence framework

  • /OF Designation: Equipped with a mechanical detent mechanism. The spool remains locked in its switched state after coil de-energization, ideal for pulse-signal control loops.

  • N9 Parameter: Outfitted with a heavy-duty concealed rubber-booted manual override button for enhanced dust and fluid protection.

• Factory Calibrated Switching Response Speeds: DC solenoid energization switching takes 50 – 60 ms; spring return centering de-energization takes 30 – 40 ms.

• Total Component Net Weight: Approx. 2.2 kgs (4.8 lbs) for dual-solenoid three-position assemblies; 1.6 kgs (3.5 lbs) for single-solenoid configurations.

Key Technical Advantages:

• Five-Chamber Rigid Monoblock High-Tensile Cast Iron Valve Body: The primary 4WE6 casing is sculpted from high-grade nodular cast iron using advanced five-chamber core casting methods. This optimized internal passage architecture cuts fluid friction pressure drops ($\Delta p$) at high velocities, preventing casting distortion or micro-expansion under 31.5 MPa cyclical switching peaks.

• Micron-Clearance Spool Processing via Match-Honing Techniques: The primary sliding spool is forged from premium low-carbon alloy steel, vacuum case-hardened to achieve HRC 58-62. The outer surface undergoes centerless cylindrical micro-grinding and mirror polishing, maintaining a precise one-sided radial clearance of 2 to 4 micrometers ($\mu m$) within the valve bore. This reduces internal bypass cross-leakage while ensuring smooth shifts.

• Oil-Immersed Wet-Pin Solenoid Architecture with Detachable Coil Design: The valve implements high-tractive wet-pin solenoids with threaded retaining sleeves. The internal armature operates fully immersed in the hydraulic fluid, which provides excellent heat dissipation, self-lubrication, and smooth damping. This configuration eliminates push-rod wear and external leakage common in dry-type alternatives.

• Fatigue-Shot-Peened Linear Centering Springs for Rapid Cycles: The internal alignment return springs are wound from premium Silicon-Chromium (SiCr) spring steel wire and finished via multi-stage shot-peening. Designed for a reliable service lifespan of over 10 million switching cycles, these springs ensure the spool returns to its center neutral position within $\le 40\text{ }ms$ upon de-energization.

Application Areas:

• Heavy-Duty CNC Machine Tools & Automated Fixture Islands: Supplying high-frequency directional shifting to hydraulic chucking subplates, high-speed tool indexers, and automated assembly clamps.

• Industrial Integrated Hydraulic Power Packs & Manifold Brackets: Directing flow loops on plastic processing machines, scrap metal balers, sheet metal shearing presses, and automated lift platforms.

• Vocational Mobile Equipment & Special Hydraulic Circuits: Operating as the electro-hydraulic pilot control core on municipal road sweepers and truck-mounted cranes.

Expert Maintenance Tips:

• Ensure Absolute Electrical Connector Dryness to Avoid Coil Burnout: The high-capacity 24V DC coils draw approximately 30W. When using these valves in humid environments or washing down machinery, verify that the internal rubber sealing gasket of the DIN 43650 plug sits completely flat and dry. Moisture entering the plug housing can cause an electrical short, which can burn out the coil or damage the controller PLC output relays.

• Enforce Strict Diagonal Torque Limits During Bolt-Down Subplate Installation: Because the radial clearance between the spool and the valve bore is only 2-4 microns, the assembly is highly sensitive to housing distortion. When securing the valve onto the subplate manifold, the 4 high-tensile M5 socket cap screws must be tightened progressively in a cross pattern to a torque limit of 8.9 – 9.5 Nm. Over-tightening with a standard hex wrench can warp the precision bore into an oval shape, causing the spool to bind up during operation.

• Maintain Strict Micron-Level Fluid Filtration to Prevent Spool Jamming: Direct-acting solenoid valves are vulnerable to fine particulate abrasive buildup. Total system fluid cleanliness must be held at or above ISO 4406 20/18/15, backed by a $\le 10$ micron pressure or return line filter element. Allowing degraded, contaminated fluid to circulate can jam fine metallic silt in the spool’s circular relief grooves, scoring the assembly or causing the spool to stick open, which can lead to uncommanded actuator movement.