What CYPULL cylinders do
CYPULL are hydraulic locking core-pulling cylinders for mould design and construction. They combine high holding forces with a compact, extremely rigid structure, so the core reaches and keeps a defined end position even under high injection pressure.
Because the locking is mechanical and self-inhibiting, the hydraulic pressure can be switched off once the cylinder is locked – for maximum process security and fast cycles.
Round vs. block design
- Round cylinder – nominal sizes 20–200 (piston Ø), rod Ø 14–140 mm. Optional round/square mounting flanges and lock nut.
- Block cylinder – short-stroke, sizes 20–80, rod Ø 14–56 mm. Compact footprint for tight mould layouts.
Both share the same locking principle and reach holding forces from 32 up to 3.300 kN, depending on series and pressure.
Locking with preload (P)
The segments create an additional preload so the core reliably touches the mould surface. The cone-shaped contour lets the rod lock within a tolerance range up to 1 mm, compensating mould elasticities. The core does not recede during injection.
Locking without preload (L)
For a completely exposed core that does not touch. The piston rod is clamped with positive lock in the end position; pressure can be switched off once locked, for maximum operational safety.
How to size the cylinder
The holding force of the cylinder must exceed the process force. The process force follows from the injection pressure acting on the projected area:
F_process [kN] = p [bar] · A [mm²] · 10⁻⁴, with A = π/4 · (D² − d²) for a touching core.
Always keep a force reserve for safety – if the process force is close to the maximum holding force, choose the next larger series.
Sensors & monitoring
Inductive sensors detect the locking state and the end positions of the piston rod, contactless and wear-free. Available as:
- PNP (up to 80 °C), PNP high-temperature (up to 120 °C) or NAMUR
- Rod side (locked/extended) or piston side (retracted)
- Straight or angled plug; retrofit for all standard series
Reading the order code
The configurator builds the full CYPULL order code automatically, for example CP-HR-P1E-063-036-0075-SLPS-SRPS-F-G. Each block has a meaning: