JPS60213330A - Production of suction and exhaust valves for internal- combustion engine - Google Patents

Abstract

PURPOSE:To manufacture in a short time without using a large-sized machine the titled valves that the shaft part and umbrella part are formed in one body by forming a short shaft part and an umbrella part with forging a large-sized billet and by finish-forming with welding of the same sized billet to the short shaft part. CONSTITUTION:A comparatively large-sized billet 2 is heated and pressed by a forging die and a short shaft part 5 is formed by extrusion and a head part 16 is subjected to up-set forging. Then an umbrella part 6 is formed by forge working of the head part 16. Further a billet 3 of the same size is welded coaxially to the short shaft part 5 by friction welding, etc. Last a finishing work of removing a flash 24 caused by the welding, etc. is performed and an exhaust valve 1 of an internal-combustion engine is formed. A process composition is thus simplified, working time is lessened and production cost is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing an intake/exhaust valve for an internal combustion engine, in which an umbrella part is integrally formed on one end of a shaft part.

Conventionally, such intake and exhaust valves have been manufactured by heating a relatively large-diameter billet made of heat-resistant steel and forging the umbrella and shaft portions with a die at the same time, or by manufacturing a pair of relatively small-diameter billets. After concentric friction welding, the burrs are removed, one end of which is electrically upset to make it larger in diameter, and then heated and then die-forged to form the umbrella part. However, with the former method, not only does the forging machine become large because a relatively large-diameter billet is forged, but also the shaft part is extruded for a relatively long length, which requires multiple steps. There is. In addition, the latter method requires friction welding of a pair of billets, removal of burrs, electric upsetting, and forging, which requires a wide range of process organization, making production line configuration difficult, and causing problems such as long processing times. There is.

The present invention has been made in view of the above circumstances, and provides an internal combustion engine intake system that not only does not require a large machine, but also shortens processing time and reduces manufacturing costs.
The present invention aims to provide a method for manufacturing an exhaust valve.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. First, in FIG. 1, for example, an exhaust valve 1 for an internal combustion engine is manufactured. First, as shown in FIG. 2 and a second billet 3 are prepared.

The first billet 2 is made of heat-resistant steel, such as austenitic or nickel-based heat-resistant steel, in order to have sufficient capacity to form the short shaft portion 5 and umbrella portion 6 that constitute a part of the shaft portion 4 of the exhaust valve 1. It is formed with a relatively large diameter. Also, the second billet 3
is made of a wear-resistant metal such as martensitic stainless steel and has approximately the same diameter as the short shaft portion 5 to constitute a portion 7 of the shaft portion 4 excluding the short shaft portion 5 .

Next, after heating the first billet 2, the first billet 2 is heated to extrude the short shaft portion 5 as shown in FIG. 1(b).
is forged, and at this time, a lower mold 8 and punch 9 as shown in FIG. 2 are used. However, prior to this extrusion forging, the first billet 2 has a conical tapered surface 1 on one end thereof.
0 is processed.

On the other hand, the lower mold 8 is provided with a large-diameter charging hole 11 into which the first billet 2 can be charged, and a short-axis forming hole 12 concentrically connected to the charging hole 11VC. The bottom portion is provided with a conical surface 14 that can define a lubricating oil reservoir 13 between it and the tapered surface 10. Further, an ejector bin 15 is inserted into the lower part of the short shaft forming hole 12.

When extruding and forging the first billet 2 using such a forging die, lubricating oil is applied to the inner surface of the charging hole 11, and then the billet 2 is inserted into the charging hole 11 so that the first billet 2 is formed on the tapered surface 1.
It is loaded with 0 facing downward.

As a result, the lubricating oil is collected in the lubricating oil reservoir 1317C. Thereafter, by pressurizing the first billet 2 with the punch 9, the first billet 2 is extruded into the short shaft forming hole 12, and the short shaft portion 5 is formed as shown in the first round (b). Moreover, at this time, the lubricating oil stored in the lubricating oil reservoir 13 flows between the extruded part and the inner surface of the short shaft forming hole 12 in accordance with the extrusion of the first billet 2, and performs a lubricating function. The extrusion moldability of section 5 is improved.

After this, as shown in FIG. 1(C), finish forming of the short shaft portion 5 and upsetting forging of the head 16 are performed, but in this process, the forging die shown in FIG. used.

In FIG. 3, the lower mold 17 is urged upward by a spring 18 and is configured to be able to move up and down, and has a conical recess 19 for upsetting forging, and a short axis communicating with the bottom sK of the recess 19. The ejector pin 21 is inserted into the lower part of the short axis forming hole 20. Furthermore, a recess 23 corresponding to the recess 19 of the lower mold 17 is formed on the lower surface of the punch 22 which moves up and down above the lower mold 17 .

In such a forging die, the material shown in FIG.
It is positioned and placed in the recess 19 of. At this time, the lower die 17 is at the upper limit position, and the position is set so that the upper end of the ejector pin 21 does not come into contact with the lower end of the short shaft portion 5 in this state. As the punch 22 is descending, the material is pressed downward, and the lower mold 17 also descends, but the lower end of the short shaft portion 5 comes into contact with the upper end of the ejector pin 21, and the final forming of the short shaft portion 5 is completed. At the same time, upsetting forging of the head 16 is performed through both recesses 19°23.

With this K, the short shaft portion 5 of a certain length is reliably finished-formed, and the head portion 16 is upset-forged to have a diameter sufficient to form the umbrella portion 6.

Next, as shown in FIG. 1G), the umbrella part 6 is forged from the head part 16 for 5K. This means that approximately half of the exhaust valve 1 has been molded.

In the next step, as shown in FIG. 1(e), the short shaft portion 5K is
, the second billet 3 is concentrically welded by friction welding or the like. From this K, the entire shape of the exhaust valve 1 is approximately formed.

Finally, by performing finishing work such as removing the burrs 24 generated by the welding, the built exhaust valve 1 is formed as shown in FIG. 1 (V), and the series of manufacturing steps is completed.

In the above embodiment, the manufacturing process of an exhaust valve for an internal combustion engine has been described, but the intake valve is also manufactured by going through the same process.

As described above, according to the present invention, there is provided a first billet in the shape of a metal round bar having a relatively large diameter and having a capacity sufficient to form a short shaft portion and an umbrella portion constituting a part of the shaft portion, and the shaft portion. A step of preparing a second billet in the shape of a metal round bar for configuring the remaining shaft portion excluding the short shaft portion with approximately the same diameter as that of the first billet; and;
A step of finish forming the short shaft portion and upsetting and forging a head having a diameter sufficient to form the umbrella portion at one end of the short shaft portion; a step of forging the head portion to form the umbrella portion. The process of concentrically welding the second billet to the other end of the short shaft part; and the process of final forming the welded part are performed in order to manufacture the intake and exhaust valves, so that it is possible to manufacture the intake and exhaust valves from a single billet. Compared to those that forge the umbrella and shaft parts, the forming load is smaller, and the forging machine can be made more compact.Compared to those that use electric upsetting, the process organization is simpler and processing time is shorter. It is possible to achieve the following effects.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG.
) ~ are diagrams showing changes in shape for each process, Figure 2 is a vertical cross-sectional view of the main part of a forging die for extruding and forging the short shaft part, Figure 3
The figure is a longitudinal cross-sectional view of a main part of a forging die used for final forming of the short shaft portion and upsetting forging of the head. 1... Exhaust valve, 2... First billet, 3... Second billet, 4... Shaft portion, 5... Short shaft portion, 6... Umbrella Patent applicant Honda Motor Co., Ltd. rθ 69 no Figure 1 6 coso 6 = no (b) (a)

Claims (1)

[Claims] A suction engine for an internal combustion engine in which an umbrella part is integrally molded on one end of the shaft part,
In the method for manufacturing an exhaust valve, a first billet in the shape of a metal round rod having a relatively large diameter and having a capacity sufficient to form a short shaft portion and an umbrella portion constituting a part of the shaft portion, and a first billet having approximately the same diameter as the shaft portion; a step of preparing a second billet in the form of a metal round bar to constitute the remaining shaft portion excluding the short shaft portion; a step of extruding and forging the first billet in order to extrude the short shaft portion of a certain length; A step of finish-forming the shaft portion and upsetting and forging a head portion having a diameter sufficient to form the umbrella portion at one end of the short shaft portion; a step of forging the head portion to form the umbrella portion; Welding a second billet concentrically to the other end of the short shaft portion;
A suction and exhaust valve for an internal combustion engine whose special mission is to manufacture suction and exhaust valves by sequentially passing through the process of final forming the welded part;
Method of manufacturing an exhaust valve.