What are the technical requirements to be observed in mechanical processing?
Time：2019-07-23 13:29:43 Click：21
In mechanical processing, what are the technical requirements that need to be followed? Only by complying with these technical requirements can the finished products processed by machinery be more standardized and reasonable. The specific technical requirements are as follows:
(1) Parts remove oxide scale.
(2) There should be no defects such as scratches, scratches, etc. on the surface of the parts.
(3) The tolerance of the unfilled shape should meet the requirements of GB1184-80, and the tolerance of the unfilled length dimension is ± 0.5mm.
(4) The tolerance zone of the casting is symmetrical to the basic size configuration of the blank casting.
(5) The assembly of rolling bearings is allowed to be hot-installed by oil heating. The temperature of the oil must not exceed 100 ° C.
(6) It is allowed to use sealing packing or sealant when assembling the hydraulic system, but it should be prevented from entering the system.
(7) Parts and components that have been assembled must have a certificate from the inspection department before they can be assembled.
(8) The parts must be cleaned and cleaned before assembly. There must be no burrs, flashes, oxide scales, rust, chips, oil stains, colorants and dust.
(9) Before assembly, the main matching dimensions of the parts and components, especially the interference fit dimensions and related accuracy, should be reviewed.
(10) During assembly, parts are not allowed to knock, bump, scratch and rust.
(11) When tightening screws, bolts and nuts, it is strictly prohibited to strike or use unsuitable screwdrivers and wrenches. Screw heads, nuts, screws and bolt heads shall not be damaged after tightening.
(12) Fasteners that require tightening torques must be torque wrenches and tightened to the specified tightening torques.
(13) After bonding, excess adhesive should be removed.
(14) The semicircular holes of the bearing outer ring and the open bearing housing and the bearing cover are not allowed to be stuck; the semicircular holes of the bearing outer ring and the open bearing housing and the bearing cover should be in good contact. The seat should be in uniform contact with the bearing cover 120 ° symmetrical to the center line and within 90 ° symmetrical to the center line. When checking with a feeler gauge within the above range, a feeler gauge of 0.03mm shall not be inserted into 1/3 of the width of the outer ring.
(15) After the outer ring of the bearing is assembled, the end face of the bearing cover at the positioning end should be in uniform contact.
(16) After the rolling bearing is installed, it should be flexible and stable to rotate by hand.
(17) The joint surfaces of the upper and lower bearing pads should be tightly fitted, and they cannot be checked with a 0.05mm feeler gauge.
(18) When the bearing pad is fixed by the positioning pin, the hinge and the distribution pin should be drilled under the condition that the opening surface and end surface of the shoe face and the end surface of the bearing hole are kept flush with each other. Do not loosen after the pin has been driven in.
(19) The alloy bearing lining is not allowed to be used when the surface is yellow, and there is no nuclear separation within the specified contact angle. The area of the nuclear separation outside the contact angle shall not be greater than 10% of the total area of the non-contact area.
(20) The reference end surface of the gear (worm gear) and the shaft shoulder (or the end surface of the positioning sleeve) should be close to each other, and it cannot be checked with a 0.05mm feeler gauge. And should ensure the perpendicularity requirements of the gear reference end face and the axis.
(21) Strictly check and remove the sharp angles, burrs and foreign objects remaining during parts processing before assembly. Ensure that the seal is not scratched when it is inserted.
(22) No cold barriers, cracks, shrinkage holes, penetrating defects and serious defects are allowed on the surface of the casting.
(23) The castings should be cleaned without burrs or burrs. Non-processing indications should be cleaned and flush with the casting surface.
(24) The casting characters and signs on the non-machined surface of the casting should be clear and legible, and the position and font should meet the requirements of the drawing.
(25) Castings should be cleared of pouring risers and flying thorns. The remaining amount of the riser on the non-processed surface should be leveled and polished to meet the surface quality requirements.
(26) The molding sand, core sand and core bone on the casting should be removed.
(27) The casting has inclined parts, and its size tolerance zone should be symmetrically arranged along the inclined surface.
(28) Correction of wrong shape and casting of bosses should be corrected to achieve a smooth transition and ensure the appearance quality.
(29) The non-machined surfaces of machine product castings need to be shot peened or roller treated to meet the cleanliness Sa2 1/2 requirements.
(30) The surface of the casting should be smooth, and the gate, burrs, and sticky sand should be removed.
(31) Castings are not allowed to have casting defects such as cold partitions, cracks, holes, etc. that are detrimental to use.
(32) Before painting the surface of all steel parts that need to be painted, rust, scale, grease, dust, dirt, salt, and dirt must be removed.