JPH11173419A - Piston for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piston for an internal combustion engine capable of improving lubrication effectively utilizing a lubricating oil which reaches a hollow inside a piston pin. SOLUTION: A piston pin hole 10 is formed on a prescribed position of a piston 1, and a hollow cylindrical piston pin 11 is mounted in the piston pin hole 10. A snap ring 15 for preventing slipping-off of the piston pin 11 is arranged on an end part of the piston pin hole 10. A dam closing plate 17 for covering a part of the hollow hole 14 of the piston pin 11 with an opening end side is arranged between the snap ring 15 and the piston pin 11. An oil reserving part 21 is formed in the hollow hole 14 of the piston pin 11 by the plate 17. Lubricating oil in the oil reserving part 21 is led between the inner circumferential surface of the piston pin hole 10 and the outer peripheral surface of the piston pin 11 through a clearance 20 between the end surface 13 of the piston pin 11 and the plate 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a piston for an internal combustion engine, and more particularly to a piston for an internal combustion engine having good lubrication between a piston pin hole and a piston pin.

[0002]

2. Description of the Related Art As shown in FIG. 6 of Japanese Patent Application Laid-Open No. 7-139629, for example, this type of piston for an internal combustion engine has a piston pin hole formed at a predetermined position of the piston, and a hollow hole is formed in the piston pin hole. A cylindrical piston pin is mounted. Also, at both ends of the piston pin hole,
A snap ring is provided for retaining the piston pin.

[0003] Lubrication of an internal combustion engine is performed by supplying lubricating oil in an oil pan to various lubricating parts by an oil pump, and is also performed using an oil splash accompanying rotation of a crankshaft. The oil that has been lubricated in each of the lubricating portions is returned to the oil pan along the wall surface of each portion.

When the lubricating oil circulates, a part of the lubricating oil also reaches the hollow inside of the piston pin during operation of the internal combustion engine when the piston pin has a hollow cylindrical shape.

[0005]

However, in the prior art, the lubricating oil that has reached the hollow inside of the piston pin during operation of the internal combustion engine only drops into the oil pan from both open ends of the piston pin. It does not serve as a special lubrication.

The present invention has been devised in view of the above-mentioned conventional circumstances, and provides a piston for an internal combustion engine having excellent lubrication by effectively utilizing the lubricating oil that has reached the hollow interior of the piston pin. Aim.

[0007]

SUMMARY OF THE INVENTION Therefore, the present invention is directed to an internal combustion engine having a piston pin hole formed at a predetermined position of a piston and a hollow cylindrical piston pin mounted in the piston pin hole. In the piston for use, a snap ring for preventing removal of the piston pin is provided at an end of the piston pin hole, and a part of the hollow hole of the piston pin is provided between the snap ring and the piston pin on the opening end side. A damming plate is provided which covers the piston pin. The damping plate forms an oil sump in the hollow hole of the piston pin, and lubricating oil in the oil sump moves between the end face of the piston pin and the damping plate. Through the gap between the inner peripheral surface of the piston pin hole and the outer peripheral surface of the piston pin.

According to a second aspect of the present invention, in the configuration of the first aspect of the present invention, the weir plate is provided with a through hole, and the lubricating oil is captured by facing the through hole. The tongue piece is formed in the configuration.

In such a configuration, when the lubricating oil circulates during operation of the internal combustion engine, a part of the lubricating oil also reaches the hollow inside of the piston pin, that is, the hollow hole.

[0010] The lubricating oil that has reached the hollow hole of the piston pin is blocked by the blocking plate, and accumulates in the oil reservoir in the hollow hole by gravity. The lubricating oil in the oil reservoir is guided between the inner peripheral surface of the piston pin hole and the outer peripheral surface of the piston pin via a gap between the end surface of the piston pin and the dam plate.

The lubricating oil that has reached between the inner peripheral surface of the piston pin hole and the outer peripheral surface of the piston pin lubricates between the piston pin hole and the piston pin, and then drops into the oil pan.

Thus, the lubricating oil that has reached the inside of the hollow hole of the piston pin during operation of the internal combustion engine is used for lubrication between the piston pin hole and the piston pin.

Therefore, the lubricating oil that has reached the hollow inside of the piston pin is effectively used, and a piston for an internal combustion engine having excellent lubrication can be obtained.

According to the second aspect of the present invention, since the lubricating oil is effectively captured by the tongue provided on the dam plate, a large amount of lubricating oil can be used for lubrication.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view of a piston for an internal combustion engine showing an embodiment of the present invention, FIG. 2 is an enlarged view of a main part of FIG. 1, FIG. And side view (b)
FIG.

In FIG. 1, reference numeral 1 denotes a piston. The piston 1 has a top crown 2 and a top 2 in FIG.
And a skirt portion 4 following the ring land portion 3. The ring land part 3
In this embodiment, three piston ring grooves 5, 6, 7 are formed in this embodiment. Of these piston ring grooves 5, 6, 7, two piston ring grooves Grooves 5 and 6 are compression ring grooves,
The piston ring groove 7 formed adjacent to the skirt portion 4 is an oil ring groove.

Reference numeral 8 denotes an apron portion formed on the skirt portion 4, and 9 denotes a pin boss portion formed so as to protrude from the apron portion 8 toward the inner peripheral side of the skirt portion 4. The apron portion 8 and the pin boss portion Numerals 9 are formed so as to face both sides of the axis Y (axial line) of the piston 1 (see FIG. 1).

The pin boss 9 is formed with a piston pin hole 10 whose both ends are open to the apron 8 facing the skirt 4. The piston pin hole 10 is formed such that its axis (axial line) X is substantially perpendicular to the axis Y of the piston 1.

A piston pin 11 is inserted into the piston pin hole 10, and a connecting rod 12 is connected to the piston pin 11.

The piston pin 11 has an axial end surface 13.
And has a hollow cylindrical shape.

Numerals 15 are snap rings provided at both ends of the piston pin hole 10 to prevent the piston pin 11 from being pulled out. The snap ring 15 is substantially C
The outer peripheral side of the piston pin hole 1
0 is mounted in a ring groove 16 formed on the inner circumference.

Reference numeral 17 denotes a blocking plate. The blocking plate 17 is provided in the piston pin hole 10 between the snap ring 15 and the piston pin 11 at a predetermined distance from the end face 13 of the piston pin 11. Is provided. The dam plate 17 is shown in FIG.
As shown in the figure, a through-hole 18 having a diameter smaller than the diameter of the hollow hole 14 of the piston pin 11 is formed in the center part in an annular shape as a whole, and the outer peripheral side thereof is the piston pin hole 1.
0 is attached to the inner circumference. In this case, the barrier plate 1
The inner peripheral portion of the through hole 18 formed in the
A part of the hollow hole 14 is covered on the opening end side, that is, on the end face 13 side.

The blocking plate 17 is provided between the snap ring 15 and the piston pin 11 at a predetermined distance from the end face 13 of the piston pin 11, so that a gap 20 is formed between the snap ring 15 and the snap ring 15. Is formed. The dam plate 17 has a through hole 18 having a diameter smaller than the diameter of the hollow hole 14 of the piston pin 11, thereby forming an oil reservoir 21 in the hollow hole 14 of the piston pin 11. That is, since the peripheral edge of the through hole 18 covers a part of the hollow hole 14 of the piston pin 11 on the opening end side, the inside of the hollow hole 14 of the piston pin 11 and the gap 20 is indicated by a two-dot chain line A. Lubricating oil can accumulate to the height shown, whereby an oil sump 21 is formed in the hollow hole 14 of the piston pin 11 (see FIGS. 1 and 2).

As a result, the lubricating oil in the oil sump 21 in the hollow hole 14 of the piston pin 11 flows through the gap 20 between the end face 13 of the piston pin 11 and the blocking plate 17. Can be guided between the inner peripheral surface of the piston pin 11 and the outer peripheral surface of the piston pin 11.

In such a configuration, when the lubricating oil circulates during operation of the internal combustion engine, part of the lubricating oil is
1, that is, the inside of the hollow hole 14 of the piston pin 11.

The lubricating oil that has reached the inside of the hollow hole 14 of the piston pin 11 is blocked by the blocking plate 17, and due to gravity, the lubricating oil 21 in the hollow hole 14 and the gap 20.
Accumulate inside.

The lubricating oil in the oil reservoir 21 and the gap 20 is guided through the gap 20 between the inner peripheral surface of the piston pin hole 10 and the outer peripheral surface of the piston pin 11.

The lubricating oil reaching between the inner peripheral surface of the piston pin hole 10 and the outer peripheral surface of the piston pin 11 lubricates between the piston pin hole 10 and the piston pin 11. The lubricating oil that has lubricated between the piston pin hole 10 and the piston pin 11 travels along these wall surfaces through a gap between the pin boss 9 and the connecting rod 12,
Drop into an oil pan (not shown).

Thus, the lubricating oil that has reached the inside of the hollow hole 14 of the piston pin 11 during operation of the internal combustion engine is used for lubrication between the piston pin hole 10 and the piston pin 11.

Therefore, the lubricating oil that has reached the hollow interior of the piston pin 11 is effectively used, and a piston for an internal combustion engine having excellent lubrication can be obtained.

FIGS. 4 to 6 show another embodiment of the present invention, which is different from the above-described embodiment.
The difference is that a tongue piece 23 for catching the lubricating oil is formed facing the through hole 18 of the blocking plate 17.

That is, a tongue 23 extending obliquely from the periphery of the through hole 18 is formed on one side surface of the blocking plate 17. The tongue piece 23 extends at the same angle from a substantially half circumference of the through hole 18 and has a semicircular inner peripheral surface 24, and its tip ends in a plane including the center line of the through hole 18. A semicircular opening 25 is formed. That is, the tongue piece 23 has a substantially semicircular funnel shape (see FIG. 6).

A projection 26 for positioning is formed on the outer periphery of the blocking plate 17, and the projection 26 is engaged with a positioning groove 27 formed in the piston pin hole 10. As a result, the blocking plate 17 is connected to the opening 2 of the tongue piece 23.
5 is positioned so as to open upward in the direction of gravity (upward in FIG. 4).

Since other configurations are substantially the same as those of the above-described embodiment, the same components as those of the above-described embodiment are denoted by the same reference numerals, and the overlapping description will be omitted.

With this configuration, when the lubricating oil circulates during operation of the internal combustion engine, similar to the above-described embodiment,
A part of the lubricating oil reaches the inside of the hollow hole 14 of the piston pin 11 and is blocked by the dam plate 17 so that the oil sump 21
Accumulate inside. At the same time, the tongue piece 23 of the dam plate 17
The lubricating oil falling from the upper side of the piston pin is effectively captured by the tongue piece 23 and guided to the oil reservoir 21 in the hollow hole 14 of the piston pin through the through hole 18.

As a result, a large amount of lubricating oil is accumulated in the oil sump 21.

The lubricating oil in the oil sump 21 flows between the inner peripheral surface of the piston pin hole 10 and the outer peripheral surface of the piston pin 11 through a gap 20 between the end face 13 of the piston pin 11 and the blocking plate 17. Guided between and provided for lubrication.

Therefore, as in the above-described embodiment, the lubricating oil that has reached the hollow interior of the piston pin 11 can be effectively used to obtain a piston for an internal combustion engine with excellent lubrication.

In addition, the tongue 23 provided on the blocking plate 17
As a result, the lubricating oil is effectively captured, so that a large amount of lubricating oil can be used for lubrication.

Although the embodiment has been described with reference to the drawings, the specific configuration is not limited to this embodiment, and can be changed without departing from the spirit of the invention.
For example, in the embodiment shown in FIGS. 4 to 6, the positioning projection 26 formed on the outer periphery of the blocking plate 17 and the positioning groove 27 with which the projection 26 engages are eliminated, and the blocking plate 17 is replaced. It is also possible to press-fit and fix it in the piston pin hole 10.

[0042]

As described in detail above, according to the present invention, a lubricating oil which has reached the hollow interior of the piston pin can be effectively used to obtain a piston for an internal combustion engine having excellent lubrication.

[Brief description of the drawings]

FIG. 1 is a sectional view of a piston for an internal combustion engine showing an embodiment of the present invention.

FIG. 2 is an enlarged view showing a main part of FIG. 1;

FIG. 3 is a drawing showing the barrier plate shown in FIG. 1 in a plan view (a) and a side view (b).

FIG. 4 is a sectional view of a piston for an internal combustion engine showing another embodiment of the present invention.

FIG. 5 is an enlarged view showing a main part of FIG. 4;

FIG. 6 is a drawing showing a plan view (a) and a side view (b) of the dam plate shown in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piston 10 Piston pin hole 11 Piston pin 14 Hollow hole 15 Snap ring 17 Barrier plate 18 Through hole 21 Oil reservoir

Claims (2)

[Claims] 1. A piston for an internal combustion engine having a piston pin hole formed at a predetermined position of a piston, and a hollow cylindrical piston pin mounted in the piston pin hole. While providing a snap ring for preventing removal of the piston pin, between the snap ring and the piston pin, a blocking plate that covers a part of the hollow hole of the piston pin on the opening end side is provided. An oil reservoir is formed in the hollow hole of the piston pin, and the lubricating oil in the oil reservoir is separated from the inner peripheral surface of the piston pin hole via a gap between the end surface of the piston pin and the blocking plate. A piston for an internal combustion engine, wherein the piston is guided between an outer peripheral surface of a piston pin. 2. A damper plate having a through hole formed therein, and a tongue piece for catching lubricating oil is formed facing the through hole. A piston for an internal combustion engine according to the above.