JPS60175714A - Mushroom valve - Google Patents

Abstract

PURPOSE:To lower the temperature of a seat surface and improve the durability by providing a groove in the connection of a valve body and a seat member and fixing an adiabatic material to this groove with the outside surface bearing against the seat member. CONSTITUTION:A valve body 1 is provided with a seat member 2 forming a seat surface 10 for a valve seat. In this case, the valve body 1 is formed on the outer peripheral portion with a groove 1a in which is fitted an adiabatic material 3 having small grooves 6 on the inner and outer surfaces. And the adiabatic material 3 is connected to the valve body 1 through a wax material 4b filled in the groove 6. Also, the valve body 1 is bonded to the seat member 2 by wax 4a. Thus, heat transmitted from a fire contacting surface 5 of mushroom valve is almost insulated by the adiabatic material 3, and the seat surface 10 has heat taken away by the valve seat so that the temperature rise of the seat surface can be restrained low, and thus the durability of the mushroom valve can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in mushroom-shaped valves used in internal combustion engines and the like.

In order to maintain the function of this type of mushroom-shaped valve, a special material with high hardness and high corrosion resistance is used for the seat member, which forms the seat surface that is repeatedly attached to and detached from the valve seat. Therefore, it is known that the durability time until combustion gas blows through depends on the hardness and corrosion resistance of the special material used for the sheet member. however,
The above findings apply when the temperature of the seat surface is kept at the same level, and the most important means of improving the durability of the mushroom-shaped valve is to lower the temperature of the seat surface as much as possible. This relatively improves the hardness and corrosion resistance of the material constituting the sheet member.

According to the experimental results to date, in a conventional mushroom-shaped valve in which Stellite #12 is overlay welded to the seat member, if the temperature of the seat surface during use is lowered by about 60°C, the high-temperature corrosion resistance will increase by about 2. It has been found that the amount increases by ~8 times.

The present invention has been made in view of the above, and an object of the present invention is to provide a mushroom-shaped valve having a configuration capable of lowering the temperature of the seat surface of the mushroom-shaped valve.

The present invention will be described in detail below with reference to FIGS. 1 and 2. FIG. 1 shows the shape and structure of a conventional mushroom-shaped valve, where 01 is the mushroom-shaped valve body, and 02 is a seat member made of a special material welded overlay to the mushroom-shaped valve body 01. It is well known that combustion gas from a diesel engine is enclosed and discharged by reversing the attachment and detachment of the seat surface formed on the seat member 02 and the seat surface of a valve seat (not shown). be.

Figure 2 shows in detail the configuration of the seat portion of the mushroom-shaped valve according to the present invention. In the figure, 1 is the valve body of the mushroom-shaped valve, and 2 is the most important part of the mushroom-shaped valve. This is a ring-shaped seat member made of a special material that constitutes the seat surface IO. The seat member 2 is different from a conventional mushroom-shaped valve.

It is not constructed by overlay welding. Further, 8 is a heat insulating material, which is fitted into a groove la machined on the outer circumference of the mushroom-shaped valve body l, and has small grooves 6 on the inner and outer surfaces. The heat insulating material 8 does not have to be in the shape of a so-called ring that is continuous over two circumferences, and may be suitably divided on the circumference and fitted together.

Also.

In FIG. 2, two ring-shaped heat insulators 3 are fitted, but the ring-shaped heat insulator 3 may be configured with one or three or more.

The heat insulating material 3 is connected to the mushroom-shaped valve body 1 via a brazing material 4b filled in the small grooves 6 on the inner and outer surfaces. This is for the purpose of facilitating smooth polishing of the surface facing the ring-shaped seat member 2 constituting the seat surface 10. Make sure that it does not separate from the main body.

Reference numeral 4a denotes a joint between the ring-shaped seat member 2 and the mushroom-shaped valve body 1, and is generally made of a brazing material.

As described above, in the present invention, the seat portion, which is the most important part of the mushroom-shaped valve, is fitted with the heat insulating material 8 into the groove 1a machined on the outer periphery of the mushroom-shaped valve body 1, and the seat part is machined on the inner and outer surfaces of the heat insulating material 8. The heat insulating material 3 and the mushroom-shaped valve body l are connected via the brazing material 4b filled in the groove 6 in advance, and the ring-shaped sheet member 2 is attached thereon, and the sheet member 2 and the mushroom-shaped valve body l are attached. It is constructed by joining the contact portion with the valve body 1 with a brazing material 4a.

According to the present invention, most of the heat flowing from the ignition surface 5 of the mushroom-shaped valve is blocked by the heat insulating material 8, and the sheet and surface 10 are made of a ring-shaped sheet member 2 made of a special material. , heat is taken away from the valve seat (not shown),
The temperature rise of 1° on the sheet surface can be suppressed to a low level. According to the experimental results shown in FIG. 2, it was confirmed that the temperature of the seat surface 10 was lowered by about 80 to 100° C. compared to the conventional mushroom-shaped valve.

On the other hand, the heat flowing in from the contact surface 5 is transferred to the sheet surface 1 as much as possible.
In order to prevent this from being transmitted to 0, it is also possible to make the heat insulating material 8 hollow, and the effect is almost the same as that of the present invention.

Next, the material used for the seat portion of the mushroom-shaped valve according to the present invention will be explained. The seat member 2 made of a ring-shaped special material constituting the seat surface 1° is the same as the conventional mushroom valve (O*-0r-W alloy (commonly known as Stellite), Ni-0r-≠-B alloy,
Although high hardness (400 to 700 HV) and highly corrosion resistant material such as Ni-Cr alloy is used, it is not constructed by conventional melt overlay welding, but is manufactured by manufacturing methods such as casting, powder sintering, and forging. Ceramic is currently the most suitable insulation material. The brazing filler metal 4a is most suitably a Ni-0r-8iB alloy, but any brazing filler metal that can withstand an operating temperature of 700 to 800°C may be used.

On the other hand, the brazing material 4b that fixes the heat insulating material 8 in the groove 1a of the mushroom-shaped valve body 1 does not necessarily have to be the same as the brazing material 4a described above. A melting point brazing material 2 such as silver solder can also be used.

The present invention is constructed as described above, and according to the present invention, the insulating material fixed to the joint portion of the valve body and the seat member in contact with the seat member allows the inflow from the contact surface of the valve. This makes it possible to block the heat from being transferred to the seat surface.

The temperature of the sheet surface can be lowered.

This makes it possible to provide a mushroom shape with significantly improved durability.

[Brief explanation of the drawing]

FIG. 1 is a front external view showing an example of a conventional mushroom-shaped valve, and FIG. 2 is a sectional view corresponding to the tab in FIG. 1, showing the structure of the mushroom-shaped valve according to the present invention. 1: Kinoko daben body, 2: Sheet member, 8: Insulation material, 4
a, 4b: brazing metal, 5: contact surface, 6: groove. Hitsuji 1 ku hai 2 flash

Claims (1)

[Claims] In a mushroom-shaped valve in which a seat member, on which a seat surface is formed with the valve seat, is fixed to the valve body by brazing, welding, etc., a groove is provided at the joint part of the valve body with the seat member, and a ceramic material is inserted into the groove. A mushroom-shaped valve characterized in that a heat insulating material made of a material such as the like is fixed by bringing its outer surface into contact with the sheet member.