Wuxi Huatong Pneumatic Manufacture
Pneumatics/Solenoid Valve/Cylinder
Main features of compact cylinders: (1) Buffering: Small bore and short stroke → low impact → typically use elastomeric buffer pads. (2) Piston Sealing: Uses either custom-profile or C-shaped bidirectional seals with oil reservoirs—supports oiled or oil-free lubrication for low friction and high reliability. (3) Magnetic Sensing: Pistons available with or without embedded magnetic rings. Barrel features a T-slot for magnetic switches, enabling non-contact position feedback. (4) Assembly: Barrel-to-end-cap connection typically uses C-clips; some models use crimped joints. (5) Variants: From base model, derivatives include: double-rod, adjustable extension/retraction stroke, dual/multi-stroke, tandem (force-boosting), guided-rod, anti-rotation, high-temp, and single-acting types. Bore: typically 12–100 mm (min 4 mm, max 125 mm); Stroke: 5–80 mm (max 150 mm). Aluminum barrel and end caps. Belongs to China’s second-generation cylinder products. Compact cylinders are 1/2–1/3 the axia...
How to choose cylinder bore? Determine the required load, then calculate the appropriate bore diameter.Selection Parameters:1. Compressed air supply pressure2. Direction of force (thrust or pull)Calculation Formulas:Thrust Force Fo = 0.25πD²PPull Force Fo = 0.25π(D² - d²)PVariables:D = Piston diameter (cm)d = Piston rod diameter (cm)P = Working pressure (kgf/cm²)Fo = Theoretical output force (kgf)Notes:1. Valid for cylinder speeds of 50–500 mm/s.2. For vertical upward mounting, usable thrust ≈ 50% of theoretical value.3. For horizontal mounting, actual force ≈ theoretical force (accounting for inertia).
应用气动技术和元件实现传动与控制的机械设备或装置，称之为气动机械。 通常，机械设备的名称并非以该设备采用的传动与控制方式命名，而是根据设备的作用取名。如机床、包装机、织布机、注塑机、半导体生产线等。这个“气动机械”，并非产品的商品名称，而是我国气动行业作为开发气动技术应用于主机的一种气动产品分类。 因此，这里所说“气动机械”仅限于内资气动企业生产的产品。 气动系统的广义概念，是按使用对象的功能要求，从压缩空气的发生装置开始，经气源处理元件、气动控制元件、信息检测元件及气动辅助元件，至气动执行元件所组成的完整回路。即气动系统是由各类元件子系统组成的。 因此，为不断扩大气动技术应用领域，我国气动企业已从早期的元件供应向气动系统开发区配套转变。同时，随着气动元件低功率、轻小型、模块式及机气电一体化，为气动系统中的部分子系统由分散安装向集中安装即开发气动系统装置的转变创造了条件。
Historically known as “heavy-duty cylinders” in China, these feature bores from 32–320 mm and strokes up to 3000 mm. Barrels are made from seamless steel tubes; end caps from steel plate or cast iron. Large-diameter piston rods are chrome-plated and polished, used in metallurgy and heavy machinery.During China’s pneumatic industry founding era (1967–1980), national focus on heavy industry drove demand. In 1975, a nationwide collaborative design effort produced the first-generation QGA (non-cushioned), QGB (adjustable cushion), and JB (fixed cushion, for metallurgy) series—bore 32–400 mm.First-Gen Design: Single-rod, double-acting. Barrels: seamless steel. Rods: 45# steel. End caps/pistons: HT250 gray iron. Tie rods: cold-drawn 35# steel. Seals: Yx-type hydraulic leather rings (no dedicated pneumatic seals existed), resulting in high starting pressure (0.2–0.35 MPa). No wear rings; front cap supported rod via bronze bushing.Despite age, these remain in service in harsh environme...
Select the solenoid valve switching mode based on the required control function for a double-acting cylinder:1. 2-Position, Single-CoilReturns to original (spring-return) position when de-energized.2. 2-Position, Double-CoilSpool shifts to the side with power applied; retains position when unpowered (“memory” function).3. 3-Position, Closed Center (Double-Coil)When unpowered, spool centers and blocks all ports. Powering either coil shifts spool to that side.4. 3-Position, Exhaust Center (Double-Coil)When unpowered, spool centers: supply blocked, cylinder ports vented to atmosphere. Powering either coil shifts spool accordingly.5. 3-Position, Pressure Center (Double-Coil)When unpowered, spool centers: supply connected to both cylinder ports (holds load). Powering either coil shifts spool to that side.
Normally Closed (NC) 2/3-Way Solenoid Valve: When the coil is energized, the air circuit opens. Once de-energized, the circuit closes immediately—this is “momentary” or “jog” operation.Normally Open (NO) 2/3-Way Single-Solenoid Valve: When the coil is energized, the air circuit closes. Once de-energized, the circuit reopens—also “momentary” operation.Double-Solenoid 2/5-Way Valve: Energizing the “forward” coil opens the forward air path (air exits the forward port). Even after de-energizing this coil, the valve remains in this position—latching until the “reverse” coil is energized.Similarly, energizing the “reverse” coil opens the reverse path and latches it until the “forward” coil is re-energized. This behavior is known as “self-locking” or “memory” function.Due to this latching characteristic, when designing electromechanical control circuits or PLC programs, the solenoid coil only needs to be pulsed for 1–2 seconds. This minimizes coil heating and significant...
Compact cylinder bore sizes typically range from Φ12 to Φ100 mm (min Φ4, max Φ125 mm), with strokes of 5–80 mm (max 150 mm). The barrel and end caps are made of aluminum alloy. These belong to China’s second-generation cylinder products, with the QGD series as the primary representative—available in single-acting and double-acting versions.Buffering: Due to small bore and short stroke, impact forces are low; most use elastomeric buffer pads.Piston Sealing: Features either custom-profile or C-shaped bidirectional seals with oil reservoirs—supporting both oiled and oil-free lubrication for low friction and high reliability.Magnetic Option: Pistons come with or without embedded magnetic rings. The barrel includes a T-slot for magnetic switches, enabling automated position sensing.Assembly: Barrel-to-end-cap connection typically uses spring steel C-clips, though some models use crimped joints.Based on the standard design, variants include: double-rod, adjustable extension/retractio...
Troubleshooting a 2/3-Way Solenoid Valve FailureI. Valve Does Not Operate When Energized• Check power wiring → reseat connectors• Verify supply voltage within ±10% tolerance → adjust• Coil desoldered → resolder• Coil shorted → replace coil• Incorrect pressure differential → adjust ΔP or replace valve• Fluid temperature too high → install high-temp valve• Contaminants jamming spool/plunger → clean; replace seals if damaged; install filter• Excessive viscosity, cycling frequency, or end-of-life → replace valveII. Valve Fails to Close• Damaged seals on spool/plunger → replace• High fluid temperature/viscosity → select appropriate valve• Contaminants in valve → clean• Spring fatigue or deformation → replace spring• Blocked balance/throttle orifice → clean• Excessive cycling or end-of-life → upgrade modelIII. Other Issues• Internal leakage → inspect seals and spring assembly• External leakage → tighten fittings or replace seals• Audible noise when energize...
Choose valve type based on actuator and application: use 4/2 or 5/2 valves for double-acting cylinders, 3/2 valves for single-acting cylinders, and 2/2 or 3/2 valves for general fluid switching.Pneumatics uses compressed air to transmit energy and signals. Air compressors store energy to drive actuators (e.g., cylinders). While cylinders can reach speeds up to 1 m/s, the optimal operating range is 50–500 mm/s—maximizing economy and minimizing wear and energy use.Recommended solenoid valve port sizes vs. cylinder bore:• φ32–50 mm → 6 mm port• φ40–80 mm → 8 mm port• φ63–125 mm → 10 mm port• φ100–200 mm → 15 mm port• φ160–250 mm → 20 mm port• φ250–400 mm → 25 mm port
I. Cylinder Operating Requirements1) Standard operating conditions: ambient and medium temperature 5–60°C, working pressure 0.4–0.6 MPa (gauge). Outside this range, use special seals and extremely dry air.2) Pressure test at 1.5× working pressure before installation; zero leakage permitted.3) If load varies significantly over the stroke, select a cylinder with sufficient force margin.4) Avoid full stroke operation—especially on extension—to prevent impact damage.5) Ensure proper lubrication. Except for oil-free cylinders, correctly install and adjust an oil mist lubricator; poor lubrication severely degrades performance or causes failure.6) Pay attention to piston rod strength. Rod threads are vulnerable to impact damage. Since rods typically handle compressive loads, consider buckling stability for long rods and sagging due to self-weight in horizontal mounting. Never subject the rod to radial loads.7) At the rod end connection, high-inertia loads cause impact upon stopping, ris...
