33results about How to "Reduce machining allowance" patented technology

A center hole machining method includes first to fifth steps. The first step includes obtaining outer peripheral shape data of a plurality of portions of the shaft blank in an axial direction. The second step includes obtaining a center axis by comparing measured data of the portions of the shaft blank with design data. The third step includes calculating a minimum distance from the center axis to the outer periphery in each of the portions of the shaft blank. The fourth step includes shifting the center axis in a direction of making the minimum distance greater than the machining dimension and repeatedly executing the third step when the minimum distance is less than or equal to the machining dimension. The fifth step includes boring the center hole in an end surface of the shaft blank at a position arranged on a line extended from the center axis.

The invention discloses a die forging technology adopting a free forging press for low-speed diesel engine cylinder heads. Steel ingots are upset, punched, chambered and drawn and then undergo head cutting and tail removing to be divided into separate blanks needed by the cylinder heads; a pre-forging die and a finish forging die are prepared, four pre-forging releasing ejection holes are uniformly formed in the bottom of the pre-forging die, four finish-forging releasing ejection holes are uniformly formed in the bottom of the finish forging die, and a pre-forging releasing ejection plate is arranged on the bottom of the pre-forging die. The interior and the exterior of a pre-forging die cavity have reverse taper, a finish forging die cavity is shaped like a simplified cylinder head contour, and machining allowance is reserved. The cylindrical blanks fully insulated are placed into the pre-forging die cavity and are pre-forged in the free forging press, and according to the shape characteristics of the cylinder heads, the cylindrical blanks are machined to form pre-forging material with the upper end walls thickened and the lower end walls thinned; the pre-forging material is placed into the finish forging die cavity for finally forming the low-speed diesel engine cylinder heads. The die forging technology has the advantages that blank manufacturing is easy, the operation is convenient, the procedure work is convenient, the machining allowance is small, the size accuracy is high, the production cost is low and the production efficiency is high, and is suitable for die forging of the low-speed diesel engine cylinder heads of various types.

The invention provides a heat treatment method of a medium carbon low-alloy steel railway wheel, comprising the following processes: heating by quenching a railway wheel at 840-860 DEG C after rollingand slow cooling, cooling by spraying water after discharging, tempering at 500+ / -10 DEG C, carrying out power frequency induction heating at 890-910 DEG C, and carrying out pressure-air cooling. Theheat treatment method aims to remarkably reduce depth of an abnormal structure area on near surface of a tread or completely eliminate the abnormal structure layer on the basis of maintaining original mechanical properties of the wheel, so as to improve use performance of the wheel and lower cutting process cost.

The invention discloses a cold forging process of a clutch sleeve. The cold forging process comprises the steps of: blanking-spheroidizing annealing-shot blasting-pretreatment-cold forging-inner hole drilling-thermal refining-sleeve boring-sleeving outside. The forging temperature of cold forging is room temperature; the product structure grains are finer, and the surfaces are not oxidized and decarbonized, so that the size precision is high, and the surface roughness is low; a traditional phosphorus saponification treatment lubricant treatment process is mature; and the mold service life is greatly prolonged.

The invention discloses a method for manufacturing an intermediate formed body of a driven gear of a rear axle of a mall and medium-sized automobile, which can improve production efficiency and reduce material consumption. The method comprises the following steps of: upsetting a blank into a workpiece; punching the workpiece and removing connected skin; pre-shaping and reaming the workpiece; and finally performing rolling formation on the workpiece to form the intermediate formed body. Compared with the prior art, the method has the advantages of reducing cutting allowance and saving raw materials because the rolling formation is adopted to eliminate defects that upper and lower end faces are not flat, the ovality of the excircle is large and the like. The upsetting, reaming, connected skin removal and the pre-shaping can be finished by an open crank press; and the open crank press can accurately control the axial height of the workpiece, so that the possibility of generating burrs, fins and the other defects in the processing process is reduced.

The invention relates to a die bending and forging finishing process of a crank blank of a low-speed diesel engine, wherein a production method is as follows: an upset crank blank is obtained through the processes of steelmaking, upsetting of a steel ingot and drawing, and then the upset crank blank is molded into a standard crank blank by the press function of a finishing punch and a backward extrusion function of an arc molding block of a finishing die through the finishing punch on an oil press of 8000T. In comparison with a traditional method, the process in the invention is capable of guaranteeing full fibers of a crank pin and a crank arm, and getting rid of secondary forging in the die forging process simultaneously, thereby achieving a purpose of finishing the forging by one time, decreasing the flowing time in the crank production process, preventing from folding a crank opening, disposing oxide skin accumulation of the opening, decreasing machining allowance of forgings, improving the internal quality of the crank forgings, the qualification rate of forging flaw detection and the material utilization rate.

The invention relates to a hinge beam integral die-forging and forming combined die. The hinge beam integral die-forging and forming combined die comprises a concave die and convex dies; the concave die consists of an outer hoop plate assembly, four concave die sections and a center punch which are fixed together by a screw; the outer hoop plate assembly comprises multiple layers of outer hoop plate rings and an outer hoop bottom plate; the center punch consists of a cylindrical punch bottom plate at the bottom and a frustoconical punch projection on the upper part, and the punch projection and the punch bottom plate are coaxial; and each concave die section consists of a convex section of which the top surface is fan-shaped, an arc-shaped vertical plate of which a side surface is L-shapedand a die section bottom plate with a 1 / 4 periphery, and a connecting ridge is arranged at a position where each die section bottom plate is connected with the corresponding arc-shaped vertical plate. The two convex dies which are perfectly matched with the concave die are used in machining. A using method of the combined die is provided. By a process mode of optimizing a die cavity and the like,the problem that the position of a lug of an existing forging and pressing die cannot be full is solved, and the method with small residual machining allowance is implemented.

The invention discloses an improved method for a driving roll used for hot rolling moulding of a rail traffic bearing collar. The improved method is characterized in that hot rolling moulding technological parameters of a high-speed train bearing collar piece are determined according to a collar blank structure; the driving roll is adopted for rolling moulding; a concave position and an initial concave amount of a concave part of a hot rolling prefabricated collar piece are determined; the hot rolling prefabricated collar piece is subjected to thermal treatment; the final concave amount at theconcave part of the pressure-quenched high-speed train bearing collar is determined; metal at the concave position is compensated on the premise of unchanging the size of the metal by changing the structure of the driving roll; and therefore the aim that no concave parts exist at the central part of the hot-rolling moulded-thermally-treated high-speed train bearing collar is realized. By adoptingthe improved method, the condition that the concave part is eradicated in a cutting mode is avoided; the utilization rate of metal is improved; machining time is reduced; and production cost of the collar piece is lowered.

The invention provides a preparation method for a silicone oil clutch housing. The preparation method comprises the following steps that S1, molten steel is smelted; S2, the molten steel is injected into a forming mould for pressure casting; S3, waste at a sprue is removed; S4, the surface of a casting is cleaned till the surface is smooth, and casting burrs are removed; S5, an insert is pressed into the casting; S6, the casting is mechanically machined to form the silicone oil clutch housing; S7, the silicone oil clutch housing is subjected to leakproofness detection; S8, the silicone oil clutch housing which is qualified after a leakproofness test is packaged and sealed for storage. The casting is fabricated through the forming mould, the precision of the casting can be guaranteed, the mechanical machining allowance is reduced, machining efficiency is improved, and meanwhile raw materials can be saved.