What technical requirements need to be followed in Changzhou mechanical processing? Only by complying with these technical requirements can the finished products of mechanical processing be more standardized and reasonable. The specific technical requirements are as follows:
(1) Remove the oxide scale from the parts.
(2) There should be no scratches, abrasions or other defects that damage the surface of the parts during machining.
(3) The unmarked shape tolerance should comply with the requirements of GB84-80, and the allowable deviation for unmarked length dimensions is± 0.5mm.
(4) The tolerance zone of the casting is symmetrical to the basic dimensional configuration of the blank casting.
(5) The assembly of rolling bearings allows the use of oil heating for hot installation, and the temperature of the oil must not exceed 00 ℃.
(6) When assembling hydraulic systems, it is allowed to use sealing fillers or sealants, but entry into the system should be prevented.
(7) The parts and components that enter the assembly must have a certificate of conformity from the inspection department before assembly can proceed.
(8) The parts must be cleaned and cleaned thoroughly before assembly, without burrs, burrs, oxide skin, rust, chips, oil stains, colorants, and dust.
(9) Before assembly, the main fitting dimensions of the parts and components, especially the interference fit dimensions and related accuracy, should be rechecked.
(10) During the assembly process, parts are not allowed to be bumped, scratched, or corroded.
(11) When tightening screws, bolts, and nuts, it is strictly prohibited to strike or use inappropriate screwdrivers and wrenches. After tightening, the screw slots, nuts, screws, and bolt heads must not be damaged.
(12) Fasteners with specified tightening torque requirements must use a torque wrench and be tightened according to the specified tightening torque.
(13) Excess adhesive should be removed after bonding.
(14) The outer ring of the bearing and the semi-circular holes of the open bearing seat and bearing cover must not be stuck; The contact between the outer ring of the bearing and the semi-circular hole of the open bearing seat and bearing cover should be good. When checking with color coating, it should be symmetrical to the centerline of the bearing seat at 20 degrees Symmetrical to the centerline 90 ° with the bearing cover; The contact should be uniform within the range of. When using a feeler gauge to check within the above range, a 0.03mm feeler gauge should not be inserted into the outer ring width by one-third.
(15) The contact between the outer ring of the bearing and the end face of the positioning end bearing cover should be even after assembly.
(16) After installing the rolling bearing, it should be flexible and stable to rotate by hand.
(17) The joint surface of the upper and lower bearing shells should be tightly fitted and cannot be checked with a 0.05mm feeler gauge.
(18) When fixing the bearing shells with locating pins, drilling and matching pins should be carried out while ensuring that the opening and closing surfaces of the bearing holes and the end faces are flush with the relevant bearing holes. After the pin is inserted, it must not loosen.
(19) When the surface of the alloy bearing liner is yellow, it is not allowed to be used. There should be no detachment within the specified contact angle, and the detachment area outside the contact angle should not exceed 0% of the total non-contact area.
(20) The reference end face of the gear (worm gear) should be in close contact with the shaft shoulder (or locating sleeve end face), and cannot be checked with a 0.05mm feeler gauge. And the perpendicularity requirements between the gear reference end face and the axis should be ensured.
(21) Before assembly, strictly inspect and remove any sharp corners, burrs, and foreign objects left during part processing. Ensure that the seal is not scratched during installation.
(22) Cold shuts, cracks, shrinkage holes, penetrating defects, and severe defects such as defects are not allowed on the surface of castings.
(23) Castings should be cleaned thoroughly without burrs or burrs. The sprue on non machined surfaces should be cleaned and flush with the surface of the casting.
(24) The casting characters and markings on the non machined surface of the casting should be clear and distinguishable, and the position and font should meet the requirements of the drawing.
(25) Castings should be cleaned of sprues, burrs, etc. The residual amount of the sprue on the non machined 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 cleaned thoroughly.
(27) If there are inclined parts in the casting, the dimensional tolerance zone should be symmetrically configured along the inclined surface.
(28) Corrections should be made to the wrong shape, convex casting deviation, etc. to achieve a smooth transition and ensure the appearance quality.
(29) Non machined surfaces of machine product castings require shot peening or drum treatment to meet the cleanliness requirement of Sa2/2 level.
(30) The surface of the casting should be flat, and the gate, burrs, and sand sticking should be removed thoroughly.
(31) Castings are not allowed to have casting defects such as cold shuts, cracks, and holes that are detrimental to use.
(32) All steel parts that require painting must have rust, oxide skin, grease, dust, soil, salt, and dirt removed from their surfaces before painting.