JPS5836170B2 - Internal combustion engine with auxiliary combustion chamber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a torch that communicates a sub-combustion chamber provided in a cylinder head with a main combustion chamber via a sub-chamber cup torch hole, ignites the air-fuel mixture in the sub-combustion chamber with a spark, and injects the mixture from the torch hole. The present invention relates to the structure of an internal combustion engine with an auxiliary combustion chamber in which the air-fuel mixture in the main combustion chamber is ignited by flame.

Conventionally, in order to fix this kind of sub-chamber cup for sub-combustion chamber into the fitting hole of the cylinder head, the cylindrical fitting part following the hemispherical head of the sub-chamber cup was inserted into the fitting hole drilled in the cylinder head. However, so-called caulking is generally performed in which the cylinder head base material near the opening of the fitting hole is deformed so as to protrude in the same direction on the outer periphery of the pre-chamber cup.

When this caulking is used, the protruding part due to plastic deformation is brought into contact with the upper surface of the shoulder part, which is the connection part between the head of the cup and the cylindrical fitting part, and fixes the sub-chamber cup so that it cannot be removed. In order to securely fix the pre-chamber cup, it is necessary to have many caulking points and to increase the amount of protrusion, and this large amount of protrusion increases the amount of plastic deformation, causing cracks at the base of the protrusion of each member. This was likely to occur, resulting in a decrease in strength and, in the worst case, the possibility that the subchamber cup would fall off.

In the present invention, the outer circumferential surface of the fitting hole is shaped so that the locking part that the shoulder part of the pre-chamber cup that is seated in the fitting hole of the two-cylinder head comes into contact with is shaped near the opening of the fitting hole. When the shoulder part and the locking part come into contact, the cylinder head base material is pressed and deformed to eliminate the gap between the fitting hole and the cylindrical fitting part of the pre-chamber cup, and the pre-chamber cup cannot be pulled out. This is intended to prevent the generation of cracks in the cylinder head base material and the falling off of the pre-chamber cup by reducing plastically deformed parts such as protruding parts due to caulking.

Next, the present invention will be explained with reference to the drawings showing embodiments.

In this example, the shape of the subchamber cup is described as one in which the head is hemispherical and the fitting part is cylindrical, but the subchamber cup is not limited to this shape, and the head and the fitting part are cylindrical. It is only necessary to have a cylindrical fitting part.

1 is a cylinder block of an internal combustion engine, 2 is a piston, 3 is a cylinder head disposed on the upper surface of the cylinder block 1, 4 is a cylinder block of an internal combustion engine;
An exhaust valve opens on the inner surface of the cylinder head, and an intake valve (not shown) also opens, and the space surrounded by these valves forms the main combustion chamber 6 of the engine.

A fitting hole 7 is formed on the inner surface of the cylinder head 3, and a sub-chamber cup 8 is fitted and fixed into the fitting hole 7 to form a sub-combustion chamber 9, and a sub-combustion chamber 9 is formed inside of the sub-combustion chamber 9. Spark plug 10
to appear.

The subchamber cup 8 has a head 11 formed into a hemispherical shape, and a plurality of torch holes 12 are bored in the head 11 so as to communicate with the main combustion chamber 6.

Fitting portion 13 of pre-chamber cup 8 into cylinder head fitting hole 7
is formed into a cylindrical shape with a diameter D, and a shoulder portion 14 is formed at the boundary with the head 11.

The bottom surface of the cylindrical fitting portion 13 of the sub-chamber cup 8 is shaped to be perpendicular or substantially perpendicular to the axis A1 of the cylindrical fitting portion 13.

On the other hand, the fitting hole 7 is a vertical circular hole 7 having a diameter D or slightly larger than D into which the cylindrical fitting part 13 of the sub-chamber cup 8 is fitted. The bottom surface 16 of this fitting hole γ is made to form a synthetic peripheral wall surface with the vertical circular hole 7'' about the axis A3 horizontally translated by
is formed into a plane perpendicular (or substantially perpendicular) to the axis A2 of the vertical circular hole 7'.

At this time, a locking part 17 of an appropriate shape such as a planar crescent shape (for example, thickness a is about 2%, maximum protrusion length b is about 1%) is integrally protruded near the opening of the fitting hole 7. .

When fitting the subchamber cup 8 into the fitting hole 7 formed in this way, insert it vertically so that the cylindrical axis A1 of the cup becomes parallel to the axis A2 of the vertical circular hole 7' of the fitting hole 7 (
(See Figure 5).

When the bottom surface of the sub-chamber cup 8 comes into contact with the bottom surface 16 of the fitting hole 7, the sub-chamber cup 8 is horizontally translated toward the locking portion 17 side.

At this time, one side of the shoulder portion 14 of the sub-chamber cup 8 comes into contact with the inner surface of the locking portion 17, and also contacts the inner surface of the vertical circular hole 7' on the opposite side of the fitting hole 7 with the locking portion 17. A gap 18 is formed between the sub-chamber cup 8 and the circumferential surface of the fitting portion 13 (see FIG. 6).

Furthermore, the cylinder head 3 is pressed so as to apply plastic deformation 19 to the vicinity of the outer periphery of the opening of the fitting hole, so that part or all of the circumferential surface of the fitting hole comes into contact with the cylindrical surface of the sub-chamber cup fitting portion 13. By pressing it, all or part of the gap 18 is eliminated, so that the sub-chamber cup 8 together with the locking portion 17 cannot be removed from the fitting hole 7 (see FIG. 7).

Next, other embodiments of the present invention will be explained.
(The same numbers as those in the first embodiment indicate the same parts) The bottom surface of the cylindrical fitting part 13 of the pre-chamber cup 8 shaped similarly to the first embodiment is made at a small angle θ1 (5 degrees) with the fitting part cylindrical axis A1. (i.e., when the bottom surface 15 of the fitting part of the sub-chamber cup 8 is seated on a horizontal surface, it is seated at an angle θ1 with respect to the cylindrical axis A1 of the fitting part of the cup).
.

On the other hand, the fitting hole 7 is connected to the cylindrical fitting part 13 of the subchamber cup 8.
is fitted into the vertical circular hole 7' with a diameter D, and an angle θ equal to or approximately equal to the angle θ1 with respect to the axis A2 of the vertical circular hole 7'.
The bottom surface 16 of this fitting hole 7 has a diameter D that is perpendicular or approximately perpendicular to the axis A2 of the vertical circular hole 7'. Shaped to be a circular plane.

Furthermore, in the vicinity of the opening of the fitting hole 7 near the inclined circular hole 7'' part, a suitable locking part 17 such as a planar crescent shape (for example, thickness a is about 2%, maximum protrusion length b is about 1%) are integrally formed in a protruding manner.

When fitting the sub-chamber cup into the fitting hole 7 formed in this way, the cylindrical axis A1 of the cup should be parallel to the axis A2 of the vertical circular hole 7' of the fitting hole 7, and the bottom surface 15 of the cup should be
and the side where the angle formed by the cylindrical circumferential surface is an obtuse angle are vertically inserted toward the side having the locking part 17 in the fitting hole 7 (see FIG. 10).

When the acute angle side of the bottom of the sub-chamber cup 8 comes into contact with the bottom 16 corners of the fitting hole 7, if the sub-chamber cup 8 is tilted toward the locking portion 17, the entire bottom surface 15 of the sub-chamber cup 8 will fit. The sub-chamber cup 8 is seated in contact with the bottom surface of the mating hole 7, and one side of the cylindrical outer circumference of the sub-chamber cup fitting portion 13 is in contact with the circumferential surface of the inclined circular hole 7'', and the sub-chamber cup 8 is fitted with its fitting portion cylindrical axis A1. Vertical circular hole 7' of hole 7
Angular change with respect to axis A2 (θ1 = θ2 or ・θ1 - Fθ
2). At this time, one side of the shoulder part 14 of the sub-chamber cup 8 comes into contact with the inner surface of the locking part 17, and the side of the fitting hole 7 that has the locking part 17 contacts the inner surface of the locking part 17. The inner surface of the vertical circular hole 7' on the opposite side and the insertion part 1 of the subchamber cup 8
A wedge-shaped gap 18 is created between the 3rd circumferential surface (11th
(see figure).

Furthermore, the cylinder head 3 is pressed so as to apply plastic deformation 19 to the vicinity of the outer periphery of the opening of the fitting hole so that part or all of the circumferential surface of the fitting hole comes into contact with the cylindrical surface of the sub-chamber cup fitting part 13. By pressing, the wedge-shaped gap 18 is eliminated, and the sub-chamber cup 8, together with the locking portion 17, cannot be removed from the fitting hole 7 (see FIG. 12).

In the third embodiment of the present invention, as shown in Fig. 2 and Figs. The fitting hole 7 to be provided is a vertical circular hole 7' having a diameter D or approximately equal to D into which the cylindrical fitting part 13 of the sub-chamber cup fits, and a circle inclined at a minute angle θ3 with respect to the axis A2 of this vertical circular hole 7. hole 7"
The bottom surface 16 of the fitting hole 8 is formed to be an approximately circular plane perpendicular or substantially perpendicular to the axis of the inclined circular hole 7''.

Further, a locking portion 17 having an appropriate shape such as a triangular planar shape is integrally formed protruding from the fitting hole 7 near the opening of the inclined circular hole 7''.

If the sub-chamber cup 8 is inserted into the fitting hole 7 shaped as described above in the same manner as in the second embodiment and is seated with its bottom surface 15 along the inclined bottom surface 16 of the fitting hole, the sub-chamber cup 8 is inclined at an angle θ3 with respect to the insertion direction toward the locking portion 17 in the fitting hole 7,
The shoulder portion 14 of the sub-chamber cup comes into contact with the inner surface of the locking portion 17, and a fitting hole and a wedge-shaped gap 18 are formed between the shoulder portion 14 and the circumferential surface of the fitting portion 13 on the opposite side. By suppressing deformation 19 of the cylinder head base material to eliminate the gap, the pre-chamber cup cannot be removed together with the locking portion.

, Incidentally, in the second and third embodiments, the case where the tilting part 17 is provided on the inclined circular hole 7'' side has been described, but the locking part 17 may be provided on the vertical circular hole 7' side. Of course.

In the case where the locking portion 17 is provided in this manner, the inclination relationship of the bottom surface 15 of the sub-chamber cup 8 and the inclination relationship of the bottom surface 16 of the fitting hole 7 are reversed to those in the second and third embodiments. It's better.

According to the present invention, the circumferential wall of the fitting hole to be fitted into the cylinder head is formed so that a locking portion with which a portion of the shoulder of the pre-chamber cup comes into contact is formed near the opening of the fitting hole, When the locking portion 17 and a part of the shoulder are brought into contact, the cylinder head base material on the side that is not in contact is plastically deformed to press the side surface of the fitting hole into contact with the side surface of the sub-chamber cup fitting part, and the sub-chamber is closed. Since the cup cannot be removed, the locking part itself that contacts the sub-chamber cup shoulder part is formed in advance and does not undergo plastic deformation and is unlikely to cause cracks.
Since plastic deformation is applied to the cylinder head so that the side surface and the side surface of the fitting hole are in contact with each other, the amount of plastic deformation is small and the deformed area does not protrude to the upper surface of the shoulder part like in the case of caulking, so combustion is prevented. This prevents the fuel from becoming a heat point, and prevents abnormal ignition, early ignition, etc.

The locking portion can be formed in a continuous strip near the opening of the fitting hole, or it can be formed independently at several locations. If the shape of the fitting hole is placed on the side, or if the suppressed deformation part of the cylinder head base material is placed on the side exposed to high temperatures, it will be less likely to become a heat point. Alternatively, it may be formed integrally at the time of casting, or a fitting hole as in the above embodiment may be formed in advance in a separate sleeve, and this sleeve may be cast at the same time as the cylinder head is cast. , manufacturing of the fitting hole becomes extremely easy.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention; FIG. 1 is a vertical side view of the internal combustion engine, FIG. 2 is a vertical side view of the pre-chamber cup, FIG. 3 is a cross-sectional view of the fitting hole, and FIG. 4 is a side view of the fitting hole. A plan view of the hole, FIG. 5 is a cross-sectional view showing the state in which the sub-chamber cup is inserted into the fitting hole, FIG. 6 is a cross-sectional view showing the state in which the sub-chamber cup is seated in the fitting hole, and FIG.
The figure is a sectional view showing a state in which the sub-chamber cup cannot be removed, and FIG. 8 is a longitudinal sectional side view of the sub-chamber cup in the second embodiment.
FIG. 9 is a sectional view of the fitting hole in the second embodiment.
Figure 0 is a cross-sectional view showing the state in which the sub-chamber cup is inserted into the fitting hole, Figure 11 is a cross-sectional view showing the state in which the sub-chamber cup is seated in the fitting hole, and Figure 12 is a cross-sectional view showing the state in which the sub-chamber cup is inserted into the fitting hole. 13 is a cross-sectional view of the fitting hole in another embodiment, FIG. 14 is a cross-sectional view showing the sub-chamber cup seated in the fitting hole, and FIG. 15 is a cross-sectional view showing the sub-chamber cup seated in the fitting hole. FIG. 3 is a sectional view showing a state in which the chamber cup cannot be removed. 3... Cylinder head, 7... Fitting hole, 8... Sub-chamber cup, 13... Cylindrical fitting part, 11... - Head, 14...Shoulder part, 17...Locking part, 18...Gap, 19...Press deformation part.

Claims (1)

[Claims] 1. In an internal combustion engine having a structure in which a pre-chamber cup for a sub-combustion chamber is fitted into a fitting hole drilled in the cylinder head, the opening of the fitting hole is formed to have the same diameter or approximately the same diameter as the outer diameter of the pre-chamber cup. death,
Further, a locking portion is provided on the circumferential wall of the fitting hole near the opening of the fitting hole to abut on a part of the shoulder provided at the connection portion between the head of the sub-chamber cup and its cylindrical fitting portion. When the shoulder part and the locking part are brought into contact with each other, the cylinder head base material on the side that creates a gap with the cylindrical fitting part of the pre-chamber cup is suppressed and deformed, making it impossible to remove the pre-chamber cup. An internal combustion engine with an auxiliary combustion chamber.