EN ISO 7285-2021 pdf free download – Pneumatic cylinders for mechanized multiple spot welding (ISO 7285:1995)
|5.2 Bore diameter
The recommended dimensions, in millimetres,are40―45-50—56—63-71—80
Tolerances shall be in accordance with ISO 4394-1—H12.6 Operating specifications
6.1 Nominal force
The nominal force shall be given at a pressure of 1 MPa (10 bar) with a tolerance of ± 5 %.6.2Return force
The return force shall not be less than 40 % of the nominal force.6.3 Maximum supply pressure
The maximum supply pressure is 1,6 MPa (16 bar).
7Construction
7.1 Point of application of the reaction
The cylinders shall function correctly when the reaction to the nominal force is being applied at amaximum distance of 28 mm from the axis of thrust.
7.2 Piston rod
The sliding bearing surfaces of the rod shall have an adequate hardness to avoid friction, wear,oxidization and any scale caused by sputtering (sparks).
7.3 Rotation
The piston rodassembly is considered as nonrotating.The anti-rotating device shall withstand, withoutbeing damaged, a rotary torque of 150 N-m applied in either direction and at any point of the travel ofthe piston rod.
7.4Seals
The seals shall be compatible with fluids used to lubricate the cylinder.
7.5 Perpendicularity —Parallelism between the mounting point and the attachmentAny faults in perpendicularity or parallelism of the bearing surface of the body of the cylinderwith respect to the axis of the shank cone of the electrode holder shall not exceed 0,2 % (forinspection, see 10.2).
7.6 Leakage
The bodies of the cylinders shall not leak in normal conditions of use (to check this, see 10.5).7.7Behaviour under pressure
The body of the cylinder shall be able to withstand without being damaged a test pressure equal to twotimes the maximum supply pressure applied for 1 min in each direction(see 10.4).
7.8 Electrode holder attachment
The electrode holder attachment shall be completely electrically insulated with respect to the body ofthe cylinder (to check this,see 10.3). This subclause does not apply to electrode holder attachmentsaccording to Nos.13 and 22.
7.9 Endurance
The cylinders shall be able to withstand the endurance test described in 10.8 according to therequirements of 10.8.5 and 10.8.6.
7.10 Finish
The outer surfaces shall be protected against cor rosion.
9Delivery conditionsThe cylinders shall be supplied- in good working order;
protected so that even after prolonged storage at the user’s premises in the original packing, all theparts likely to deteriorate (rods, seals, internal surfaces,cones, openings, etc.)retain the qualitiesrequired by Is0 7285;
with the openings stopped up;
– in packing the outside of which is marked with the identification specified in clause 8.10 Inspection and type tests
10.1 Visual inspection
Conformity to the specifications of 7.10 and clauses 8 and 9 is checked by visual inspection.10.2 Dimensional inspection
Dimensional inspection includes
– verification of conformity with the drawings;
10.3 Inspection of the electrical insulation of the electrode holder attachment
A voltage of 48 v d.c. is applied between the attachment and the mounting.The resistance shall not beless than 1 MQ.
10.4 Pressure type test
Conformity with the specifications of 7.7 is checked by applying a liquid (water) pressure of 3,2 MPa(32 bar) at the inlet or outlet of the cylinder for 1 min in each direction.After drying,the cylinder issubjected to the test described in 10.5.
10.5 Leak type test
The cylinder supplied with air is immersed in water.The test is carried out attwo different air pressures,0,2 MPa (2 bar) and 1,0 MPa (10 bar), which shall be kept constant for 1 min and in the forward andreturn position. No air bubbles shall appear when a new cylinder is tested.
10.6 Separation force type test
The supplied pressure of the cylinder shall increase progressively from 0 MPa (0 bar) to 0,1 MPa (1bar).The movement of the piston shall commence before 0,1 MPa (1 bar) and shall continue smoothlywithout jolts.Before the test, carry out five forward and return cycles.
10.7 Nominal force type test
The measuring device shall be accurate to ± 1,5%.10.8 Endurance type test
For the purpose of this endurance type test, cylinders of nominal force of 2,86 kN and 4,61 kN and of50 mm stroke serve as reference.EN ISO 7285 pdf download.