JPS5941005B2 - Kinoko dialect - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to mechanical valves, and more particularly to mushroom valves for internal combustion engines cooled by circulation of cooling fluid.

This type of valve generally consists of a stem and a head assembled to the stem, and this assembly consists of a threaded surface provided on the periphery near one end of the stem, and a threaded surface provided in the axial direction of the head. This is done by screwing into the hole.

However, it is normal for a small gap to remain between the thread groove and the thread, so fill that gap with solder to further secure the stem and head.

It is extremely important to have a high stiffness in the valve head and stem assembly, which prevents cooling fluid from leaking through the seam between the head and stem.

Furthermore, it is important that the valve head and valve seat are in perfect contact, which creates a cavity that allows the cooling fluid to circulate, especially in mushroom valves that are cooled by cooling fluid circulation. The partially hollow nature of the head creates the problem of rapid deformation under the action of high temperatures compared to a flat head structure.

The present invention provides a new valve structure, particularly a valve head structure, in which the head and stem are well connected and the valve has high impact resistance against the valve seat.

In order to obtain a good bond between the head and stem, it is desirable to make the bonding area between the two as large as possible.
On the one hand, this means limiting the size of the cooling cavity within the valve head.

Consideration in this regard is important.

This is because it presents problems that must be solved at the same time regarding cooling systems that use oil as a refrigerant.

In fact, to eliminate insufficient cooling oil reflux and also to avoid oil extrusion due to vibrations seen in case of incomplete filling of cooling oil, in particular to the hot parts of the valve, known as the shaker effect, in other words. For example, in order to avoid overheating of oil stagnant in a part of the cooling system, it is desirable that the cooling cavity be filled with a cooling fluid.

Such overheating may have the following harmful consequences:

That is, overheating may promote decomposition and carbonization of the cooling oil, resulting in blockage of the cooling oil passages.

This possibility is particularly high in the annular chamber portion of the valve where the cross-sectional area of the valve is significantly larger than the cross-sectional area of the cooling fluid supply conduit.

Therefore, the present invention solves two problems simultaneously.

In fact, in this case, the solution of the - problem automatically leads to the solution of the other problem, and the cross-sectional area of the annular cooling chamber in the valve head is increased in order to increase the joint interface between the head and stay space. Reduction ensures better cooling fluid circulation.

Conversely, reducing the cross-sectional area of the annular cooling chamber to ensure better cooling fluid circulation will automatically increase the head-stem joint interface area.

The present invention therefore includes two cooling fluid supply return pipes of substantially vertical shape and constituted by a stem and an annular head forming two parts assembled together, the pipes being disposed within the valve stem. two substantially horizontally shaped cooling fluid return pipes, the latter being machined in the valve head and connected to an annular chamber machined in the same head. and that the assembly of the head to the stem is completed only by brazing across their entire interface, and that the cross-sections of the cooling fluid passages in the valve head and stem have different shapes but approximately the same cross-sectional area. The present invention provides a mushroom valve for an internal combustion engine, in particular of the type that recirculates a cooling fluid, such as oil.

Hereinafter, the present invention will be described in detail with reference to the drawings.

Referring first to FIG. 1, the valve 1 of the invention has a stem 2 and an annular head 3 fixed to the end of the stem 2.

Near the end of the stem 2 which is associated with the head 3, a cylindrical part 4 is provided, and on the outside of the cylindrical part a threaded part 5 is provided.

On the outside of the cylindrical part 4 there is a further cylindrical part 6 of a larger diameter, and between the two cylindrical parts 4 and 6 a shoulder 7 is formed.

The head 3 has a trapezoidal shape with a stem 2 in its center.
A screw hole 8 into which the screw portion 5 is screwed is provided.

This screw hole terminates in a hole 9 with a larger diameter.

A recess 10 is provided in the inner wall of the hole 9 in a portion facing the shoulder 7 of the stem 2 so that an annular cooling passage 11 is formed when the steno 2 and the head 3 are assembled.

The cooling passage 11 communicates with two non-concentric longitudinal passages 12, 13 provided inside the stem 2 along its longitudinal axis via transverse passages 14, 15, respectively.

The passages 12 and 13 are respectively connected to an outwardly open inlet 16 and an outlet 17 for cooling fluid.

The passage 12.13 is closed by a member 18 which is welded to the end of the stem 2 opposite the end screwed into the head 3.

This member 18 is associated with a rocker arm (not shown) of the valve 1.

The head 3 is provided with an annular sealing surface 20.

This sealing surface contacts a valve seat (not shown) provided in the cylinder head when the valve is in the closed position.

A threaded portion 5 provided in the cylindrical portion 4 of the stem 2
is assembled to the head 3 by screwing it into the screw hole 8 of the head 3 and brazing or hard soldering the entire surface of the joining surface, that is, the periphery of the cylindrical portion 4 of the stem 2 and the large diameter cylindrical portion 6. Fixed.

When the assembly is completed, the end face of the cylindrical part forming the terminal face of the end of the stem 2 is flush with the corresponding end face of the head of the valve and forms the central part of the head 3.

The soldering or hard soldering is carried out in a known manner using a soldering ring 21 which is heated after being installed.

Refer now to FIG.

This figure shows a valve that differs from the valve shown in FIG. 1 in that assembly is performed only by soldering or hard soldering.

In this case, the cylindrical part 4 of the stem 2 is not provided with a threaded part 5, but in order to form a shoulder 7' identical to the shoulder 7 shown in FIG. 23 is only provided on the head 3.

Furthermore, an annular cooling passage is formed between an annular setback 24 provided on the inner surface of the cylindrical end 6 of the stem 2 and a corresponding portion of the shoulder 7' of the head 3.

Since the assembly of this valve is carried out only by brazing, the interface between the head and the stem can have any shape, preferably one that is easy to manufacture.

With the valve of the present invention, the stem 2 and head 3 are in continuous contact over almost the entire joint surface, so the joint is extremely strong and is very resistant to shock when the valve contacts the valve seat. There is a considerable advantage of endurance.

Also, shoulder 7. γ' not only ensures good alignment and contact when assembling the head 3 and stem 2, but also prevents accidents such as the head falling into the cylinder even if the joint between the head and stem is broken. .

On the other hand, as shown on both actual flow sides, cooling passages 12°, 13.
14 and 15 and the annular chamber 11 have different cross-sectional shapes but have substantially the same cross-sectional area, so that complete circulation of oil in the cooling system can be ensured.

Therefore, the hollow volume of the valve containing cooling oil is always 100% filled with oil, resulting in decomposition, alteration, and carbonization of the oil caused by overheating of the stagnant oil, resulting in blockage of the cooling fluid passages, especially in the annular cooling chamber. It is possible to avoid this.

Therefore, by reducing the cross-sectional area of the valve cooling chamber, the area of the joint interface between the stem and the head can be increased and the stem-head assembly can be made more robust.

By making the cross-sectional area of the cooling chamber substantially equal to the cross-sectional area of the supply pipes and smaller than before, better cooling oil circulation is achieved and the dangers associated with overheating of stagnant oil in the cooling system are avoided. be done.

Conversely, the good circulation of the cooling fluid brought about by the reduced cross-sectional area of the annular cooling chamber increases the stem-head joint interface, further allowing for a more robust assembly of the stem-head.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an embodiment of the valve of the present invention in which the head and stem are assembled by screwing and soldering, and FIG. 2 is a longitudinal sectional view of an embodiment of the valve of the present invention in which the head and stem are assembled by only soldering. FIG. 7 is a longitudinal cross-sectional view of another embodiment. 1... Valve, 2... Stem, 3...
...Head, 4... Cylindrical sound is 5...
・Threaded part, γ...shoulder, 8...screw hole,
9... hole, 10... hollow, 11...
...Cooling passage, 12, 13, 14, 15...
・Passage, 16...Cooling fluid inlet, 17...
...Cooling fluid outlet, 20...Annular sealing surface, 2
1... Wax ring.

Claims (1)

[Claims] 1. A mushroom valve for an internal combustion engine, comprising a stem and a head that are assembled to each other, and a plurality of non-concentric fluid return passages are formed, the stem being concentrically surrounded by the head and passing through the head to form a head. a first cylindrical hole having a predetermined diameter, the head having an end extending to an end surface, the head being fitted into the stem end and fixed to the stem end by brazing along the joining surface of the head and the stem; a second cylindrical hole having a larger diameter than the first cylindrical hole and fitted into the stem end so as to form a shoulder with the first cylindrical hole, so that the head end surface and the stem end surface are the same; the fluid return passageway has a plurality of longitudinal passageways in the stem and a transverse passageway connected at one end to each longitudinal passageway and to an annular chamber at the other end, the longitudinal and transverse passageways being planar; and the annular chamber have different cross-sectional shapes but substantially the same cross-sectional area.