JPH025704A - Intake/exhaust valve for engine and manufacture thereof - Google Patents

Abstract

PURPOSE:To aim at improvement of productivity by welding and joining a shade shaped valve body with a pipelike stem to product an intake/exhaust valve. CONSTITUTION:A heat resistant steel, etc. made pipe is cut to required length to form a stem 11 by swaging or the like. Meantime, a shade shaped valve body 14 is separately producted by forging, sintering, etc. The through hole of the valve body 14 is fitted to the large diameter portion 12 of the stem 11 and its fitting portion is joined by welding 18. Boring by cutting work and polishing work for the hollow stem 11 become unnecessary. Accordingly, productivity can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an engine intake and exhaust valve and a manufacturing method thereof.

<Conventional technology> In order to reduce the weight of engine valve train parts and cope with continuous high-load operation, the stems of engine intake and exhaust valves are made hollow, and metallic sodium is filled in the hollow to reduce the weight of engine valve train parts and to cope with high-load continuous operation. Intake and exhaust valves that are cooled by pipe action are used in aircraft engines and racing car engines.

Recently, it is being adopted in general automobile engines.
The challenge is to improve productivity and reduce costs.

The conventional manufacturing method for intake and exhaust valves with hollow stems, as shown in Fig. 7, includes the step (I) of cutting a heat-resistant steel round bar 1 to the required length, and the process of forging this round bar 1 into a stem 2. Step (IF) of forming an umbrella-shaped valve body 3; machining a hole 4 long in the axial direction of the stem 2; and a lid hole 5 communicating with the hole 4 on the end face of the valve body 3. Step (1) and the hole 4
The product was manufactured through a step (IV) of filling the metal sodium into the hole 5 and fitting an M6 hole into the hole 5, and a step (V) of pre-machining a groove 7 for attaching the stem 2 to the end of the stem 2 using a tR machine.

<Problem to be solved by the invention> In the case of the conventional manufacturing method described above, not only does it require a large number of steps, but also cutting tools such as drills are required to machine the holes 4.5 in heat-resistant steel, which is a difficult-to-cut material. The inner diameter of the hole 4 had to be finished by polishing, since the productivity would be poor due to cutting damage, and if the cutting tool marks left during machining were left on the inner diameter of the hole 4, it would be disadvantageous in terms of strength. Furthermore, the material yield is poor and the varnish l-high.

Means for Solving the Problems> The present invention solves the above conventional problems, and the intake and exhaust valves have a stem made of a pipe made of heat-resistant steel, etc., and an umbrella-shaped end at one end of the pipe stem. The valve body is welded together.

In addition, the manufacturing method for this intake and exhaust valve is to form a pipe stem with a large diameter at one end by forming steps on a pipe made of heat-resistant steel or the like through plastic processing, and then providing a hole that fits into the large diameter part of this pipe stem. An umbrella-shaped valve body is made, this valve body is fitted into the large diameter portion of the pipe stem, and this fitting portion is welded and joined.

Effects> With the above configuration, the present invention eliminates the need for drilling a hole by cutting machining or polishing the hole for the hollow stem.
We provide high-strength intake and exhaust valves at high production and low cost.

<Example> Hereinafter, an example of the present invention will be described based on the drawings. first,
As shown in FIG. 5, the intake and exhaust valve according to the present invention has a stem 11 made of a pipe made of heat-resistant steel, etc., and one end of the stem 11 made of this pipe is forged, sintered, etc. with a material having high heat resistance and wear resistance. The structure is such that an umbrella-shaped valve body 14 made of steel is joined and fixed by welding 12.

A method of manufacturing the intake and exhaust valves having the above configuration will be explained.

As shown in FIG. 1, a pipe 10 made of heat-resistant steel or the like is cut to a required length. The diameter of this pipe 10 is larger than the diameter D1 of a stem 11, which will be described later.

This pipe 10 is formed into the shape of the stem 11 shown in FIG. 2 by swaging or the like. That is, in addition to setting the required diameter D1 for the valve stem, the diameter D2 of the large diameter portion of -C is also formed to the required size, and a cock (not shown) is fitted to the other end. The stem 11 is made of a pipe by forming a groove 13 for the purpose.

On the other hand, the umbrella-shaped valve body 14 is separately manufactured by forging, sintering, etc. from a heat-resistant and wear-resistant material, as shown in FIG. As shown in FIG. 3 (8), this valve body 14 has a through hole 1 having a diameter d2 that fits into the diameter D2 of the large diameter portion 12 of the stem 11.
5 is formed. Further, as shown in FIG. 3(B), a bottomed hole 16 having a diameter d2 may be used.

Next, the large diameter portion 12 of the stem 11 is fitted into the through hole 15 or the bottomed hole 16 of the valve body 14, and the fitting portion is welded 18 to join as shown in FIG. Valve body 1 of bottomed hole 16
In the case of No. 4, as shown in FIG. 4 FB), one end of the stem 11 by the pipe is inevitably closed by fitting the valve body 14 into the large diameter portion 12 of the stem 11 and welding 18.

On the other hand, in the case of the valve body 14 in the through hole 17, as shown in FIG. 4(A), the cover plate 17 is fitted into the through hole 15, and the cover plate 17 is welded 18 together. For the welding 18, for example, electron beam, laser, etc. are suitable.

With this, the stem 11 made of a pipe as shown in FIG.
An intake/exhaust valve product is obtained with an umbrella-shaped valve body 14 that is separate from the stem 11 and joined by welding 18, and the hollow of the stem 11 is filled with metallic sodium.
M2S is welded to the other end of 1 to make a completed product. In the above embodiment, the valve body 14 is fitted and welded to the outer diameter of the stem 11, but as shown in FIG. 6 (8) (B), the valve body 14 is fitted to the inner diameter 12a of the stem 11. Joint welding is also possible.

<Effects of the Invention> As described above, according to the present invention, the following special effects are achieved.

Hollow stems are formed into the desired shape by swaging, etc., so there is no need to cut and machine the shaft hole like in the past, and there is no cutting damage on the inner diameter, so there is no need to polish or finish the inner diameter. , improve productivity and reduce costs.

In addition, since the stem is made of pipe material, it is possible to significantly reduce costs and improve reliability compared to conventional solid stems with holes drilled. Strength is ensured by forming the grooves.

Furthermore, by fitting and welding an umbrella-shaped valve body to the large diameter portion of the stem, the rounded portion connected to the large diameter portion 12 shown at 20 in Fig. 5, which is disadvantageous in terms of strength, can be removed and the valve body It can be fixed by welding, and the welding area can be made as necessary and sufficient by appropriately designing the dimensions of the large diameter part.

Further, since the stem and the umbrella-shaped valve body can be selected relatively freely by simply considering mutual weldability, a combination can be achieved at low cost and with a good balance of strength.

As a whole, the present invention has the advantage of providing a valve with good balance of strength, excellent productivity, high reliability, and low cost.

[Brief explanation of the drawing]

Figures 1 to 5 show the features of the present invention! ! ! 1.
The figure is a cross-sectional view of the pipe that is the material of the stem, Figure 2 is a cross-sectional view of the stem formed from the pipe, Figure 3 (A), +
8) is a sectional view of an umbrella-shaped valve body, FIGS. 4(A) and 4(B) are sectional views of the stem and valve body welded together, FIG. 5 is a sectional view of the finished product of the present invention, and FIG. Figures (A) and fB) are sectional views of main parts showing other embodiments of the present invention, and Fig. 7 is a diagram of a conventional manufacturing process. DESCRIPTION OF SYMBOLS 10... Pipe, 11... Stem, 12... Large diameter part, 13... Clear, 14... Valve body, 15... Through hole, 16... Bottomed hole, 17... ... Lid plate, 18... Welding, 19... Lid. Patent applicant Hino Motors Co., Ltd. Figure 4 Figure 6 (A) (B) (A) Figure 7 (I[I) (P

Claims (2)

[Claims] (1) An engine intake/exhaust valve comprising a stem and an umbrella-shaped valve body at one end of the stem, the stem being a pipe made of heat-resistant steel or the like, and an umbrella-shaped valve body at one end of the pipe stem. Engine intake and exhaust valves made by welding. (2) A heat-resistant steel pipe is formed with steps by plastic processing to form a pipe stem with a large diameter at one end, and an umbrella-shaped valve body with a hole that fits into the large diameter part of this pipe stem is made. A method of manufacturing an intake and exhaust valve for an engine, comprising fitting the body into the large diameter portion of the pipe stem, and joining the fitting portion by welding.