Overview - ISO 7285:1995 (Pneumatic cylinders for mechanized multiple spot welding)
ISO 7285:1995 specifies geometrical and mechanical requirements, manufacturing, delivery and test specifications for pneumatic cylinders used on mechanized multiple spot welding machines. The standard covers double‑acting cylinders with two piston stages for the working stroke and one stage for return, nominal forces and strokes, mounting methods, electrode‑holder attachment details, performance tests and marking/delivery requirements.
Key topics and technical requirements
- Nominal characteristics
- Standardized nominal forces (kN) at 1 MPa (10 bar) - e.g. 2.19, 2.86, 3.61, 4.61, 5.92, 7.60, 9.74.
- Standardized nominal strokes and outside dimensions (see annex C for dimension tables).
- Bore diameters and tolerances referenced to ISO 4394‑1.
- Operating limits
- Maximum supply pressure: 1.6 MPa (16 bar).
- Nominal force specified at 1 MPa with +5% tolerance; return force ≥ 40% of nominal.
- Construction and mechanical requirements
- Anti‑rotation device must resist 150 N·m torque.
- Seals compatible with lubricants used; surfaces protected against corrosion.
- Electrode‑holder attachment must be electrically insulated from the cylinder body (exceptions noted).
- Mounting methods
- Annex A defines mounting methods (A–H) and annex C gives detailed mounting dimensions.
- Marking and delivery
- Permanent identification (alphanumeric symbol), manufacturer name, reference to ISO 7285 and rating plate data.
- Delivery in original packing, openings stopped, corrosion protection for long storage.
- Inspection and type tests
- Visual and dimensional inspection; perpendicularity/parallelism checks.
- water at 3.2 MPa (32 bar) for 1 min (see clause 10.4).
