Inverted extrusion molding process of high pressure cylinder and inverted extrusion die adopted in inverted extrusion molding process

Abstract

The invention discloses an inverted extrusion molding process of a high pressure cylinder and an inverted extrusion die adopted in the inverted extrusion molding process. The process includes the steps that a blank is heated to 800 DEG C after being blanked and is kept at the temperature for 90 minutes, and then the blank is heated to 1180 + / - 10 DEG C and kept at the temperature for 9 minutes; and the die is heated to 250-350 DEG C, a flange is subjected to upsetting in advance, then subjected to inverted extrusion molding, heated in a heating furnace to 910+ / -10 DEG C and kept at the temperature for 3.5 h, then air cooling is carried out, and finally a sample is fetched and subjected to physical and chemical inspection. A circle of outwards protruding annular extrusion belt is formed at the lower end of an upper die punch of the inverted extrusion die, a cylinder barrel female die is fixedly arranged on a lower die cushion plate, and the punch corresponds to a female die cavity of the cylinder barrel female die. A female die outer ring and a female die inner ring of a lower die make contact through a taper plane. An ejector rod of the lower die stretches into a penetrating hole of the cushion plate. A discharging device on the lower die can just be located over a workpiece in the female die cavity in a blocking mode. By means of the inverted extrusion molding process of the high pressure cylinder and the inverted extrusion die adopted in the inverted extrusion molding process, extrusion molding and demolding of a cylinder barrel with no draft bevel angle are achieved, the product structure is compact, the intensity is high, and usage is reliable and safe.

Description

technical field [0001] The invention relates to a processing method of a high-pressure oil cylinder and related dies, in particular to a reverse extrusion forming process of a high-pressure oil cylinder and a reverse extrusion die used therein. Background technique [0002] Cylinder is an important pressure-capacity component in hydraulic machinery. Domestic hydraulic transmission is widely used, and there are many specifications and standards for high and low pressure cylinders. However, contemporary high-tech places higher requirements on the range and performance of hydraulic machinery, which promotes ultra-high pressure. In the development of oil cylinders, oil cylinders characterized by small pipe diameter, slender shaft, thin pipe wall, high pressure resistance and light weight have become one of the important development directions of engineering hydraulic machinery. Manufactured a new type of oil cylinder specification, the cylinder forging material of the high-press...

AI Technical Summary

Problems solved by technology

[0002] Cylinder is an important pressure-capacity component in hydraulic machinery. Domestic hydraulic transmission is widely used, and there are many specifications and standards for high and low pressure cylinders. However, contemporary high-tech places higher requirements on the range and performance of hydraulic machinery, which promotes ultra-high pressure. In the development of oil cylinders, oil cylinders characterized by small pipe diameter, slender shaft, thin pipe wall, high pressure resistance and light weight have become one of the important development directions of engineering hydraulic machinery. Manufactured a new type of oil cylinder specification, the cylinder forging material of the high-pressure cylinder: 20Mn; Ratio: 5.4; 2. The cylinder wall is thin (wall thickness: 52mm); 3. The center of the cylinder requires high precision (concentricity deviation ± 0.25mm); 4. Decarburization layer: ≤ 1.5mm; grain size reaches 5 It can be seen from the above data that the structure of the cylinder is complex, the technical requirements are high, and the forming is difficult. If it is processed by the traditional forging (free forging + machining) method, the forging ratio and performance cannot meet the requirements.

Images