A kind of hollow sodium-filled valve forming method for extruding billet

Abstract

The invention discloses a forming method of a hollow sodium-filled valve for extrusion blank forming. The method comprises the steps that according to the dimension of a valve product, a wall thickness pipe is selected as an initial blank; the wall thickness pipe is heated and extruded, so that one end of the wall thickness pipe is made to form a hollow valve rod part; then through a rotary forging forming technique, the other end of the wall thickness pipe is made to form a disc part of the valve; the disc part of the valve is machined and sealed; the interior of the valve is machined, cleaned, dried and filled with sodium; then the valve rod part is machined and sealed; and finally the hollow sodium-filled valve is obtained. The forming technique is easy and convenient to operate, by the adoption of the technique, the utilization rate of materials can be effectively increased, the production cost is reduced, the production efficiency is improved, the volume of an inner cavity of the produced valve is larger, and the heat dissipation performance is better.

Description

technical field [0001] The invention relates to the technical field of engine valve manufacturing, in particular to a hollow sodium-filled valve forming process for an engine by extrusion billet making and swing rolling forming. Background technique [0002] The valve is a precision part that seals the combustion chamber and controls the gas exchange of the internal combustion engine during the working process of the internal combustion engine. It is a key component to ensure the power performance, reliability and durability of the internal combustion engine. As people have higher and higher requirements for the lightweight of automobiles, various automobile companies have also put forward higher requirements for engines, and valves, as an important part of the engine, have more and more stringent requirements for their quality and working conditions. In this regard, the hollow sodium-filled valve emerged as a new type of valve. Compared with the traditional solid valve, thi...

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Problems solved by technology

In this regard, the hollow sodium-filled valve emerged as a new type of valve. Compared with the traditional solid valve, this valve is not only light in weight but also has good heat dissipation. Research, such as: the patent No. CN200910231600 discloses a hollow sodium-filled valve and its manufacturing method. The method adopts the back-extrusion method to form the valve. It first heats the cylindrical blank, and passes through a steel core. The mold extrudes the blank to obtain the initial shape of the valve, and then performs precision forging to obtain the head shape of the valve. After the forging is completed, the mandrel is pulled out, and then the inner hole of the valve is cleaned and dried, and the metal sodium is poured into it. Finally, the sealing is carried out. Due to the large extrusion force in the forming process of this method, the high tonnage of equipment required, and the severe wear of the mold, resulting in high valve manufacturing costs, it is difficult to promote in China

The method provided by the patent No. 201120224645.5 is to form a solid valve first, then drill a hole from the valve rod end through a drilling process, fill the hole with sodium metal and then plug the rod end, although the forming method The process is simple, but the valve disc end produced by this method has no cavity, less sodium filling, and poor heat dissipation performance

[0003] In addition, the document with the patent number 201410249979.6 discloses a manufacturing method of a disk-end airtight and hollow sodium-filled valve. The method is to first use an electrothermal upsetting process to shape one end of the slender bar into a "garlic head" shape to obtain a solid valve. Preform the blank, then forge the preformed blank into the shape of the valve through the forging process, and then use machining to process three steps on the end face of the valve disc, and then drill the rod from the end of the disc, fill the hole with sodium and remove it. The end face of the disc is blocked, although the hollow air valve formed by this method also has an inner cavity at the end of the disc, the amount of sodium filling is increased, and the heat dissipation performance is improved, but this kind of solid valve is formed first and then processed into a hollow air valve. The door method has low material utilization rate and many processes, and the quality of the preformed blanks produced by the electrothermal upsetting process is poor, the accuracy is difficult to guarantee, and the production efficiency is low

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