JPH077570Y2 - piston - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an engine piston, and more particularly to a piston for a high speed engine.

[Conventional technology]

FIG. 6 is a bottom view showing a piston of a conventional engine for high speed rotation.

In order to reduce the friction between the weight of the piston and the inner wall of the cylinder, the piston A has a pair of arc-shaped skirts B, B that slide on the inner wall of the cylinder and have a short circumferential width, and a pair of arc-shaped skirts. A peripheral wall C of the piston A is thinly formed except for a portion G surrounded by B and B and continuous walls B ′ and B ′ that continuously form the skirts B and B.

FIG. 7 and FIG. 7 shown in a section taken along line II of FIG.
As shown in FIG. 8 which is a sectional view taken along the line II-II in the figure, a plurality of oil return holes D are formed through the oil ring groove E only in the skirts B and B.

According to the conventional piston described above, as shown in FIGS. 7 and 8, the oil ring groove E provided in the peripheral wall C is provided.
In FIG. 3, the part where the oil return hole D is provided is only a part of the pair of arc-shaped skirts B, B, and the cooling oil is supplied from the parts of the skirts B, B to the skirts B, B and this skirt. The structure is such that it flows into a portion G surrounded by continuous walls B ′ and B ′ (FIG. 6) that continuously form B and B, and does not flow from other peripheral wall C.

By the way, according to the above-described conventional piston A, the cooling oil passes through the oil return holes D formed in the skirts B and B, and the skirts B and B and the continuous wall between the skirts B and B are continuously formed. Since the cooling oil discharged into the portion G surrounded by B'and B '(FIG. 6) and further discharged falls from this portion G downwardly, the falling cooling oil is There has been a problem that the efficiency of collecting the cooling oil is remarkably reduced by adhering to a connecting rod or the like (not shown) arranged in the portion G.

[Purpose of device]

The present invention has been made in view of the above circumstances, and an object thereof is to provide a piston configured to increase the amount of cooling oil recovered.

[Constitution of device]

In order to achieve the above-mentioned object, in the present invention, a pair of arc-shaped skirts having a short circumferential width and facing each other, and a continuous wall continuously formed so as to surround the pair of arc-shaped skirts. And a bottom surface of the piston located outside the portion surrounded by the pair of arc-shaped skirts and the continuous wall and outside the piston pin boss wall in which the piston pin fitting insertion hole is formed. An oil hole that is substantially vertical from the bottom surface of the piston and has a part of the peripheral edge communicating with the oil ring groove of the piston, and the cooling oil discharged from the oil hole through the oil ring groove is formed. The pair of skirts and the continuous wall are made to fall downward without hanging on the portion located below the portion surrounded by the continuous wall.

〔Example〕

 The piston according to the present invention will be described in detail below.

FIG. 1 is a bottom view of a piston 1 according to the present invention.

A pair of arcuate skirts 3 and 3 having a short circumferential width are formed on the peripheral wall 2 of the piston 1 so as to face each other, and the lower parts of the skirts 3 are along the line III-III in FIG. The bottom surface 4 of the piston 1 as shown in FIG.
It is formed so as to project from. In FIG. 1, reference numeral 3'denotes a continuous wall that is continuously formed so as to surround a pair of arcuate skirts 3 and 3.

On the other hand, as shown in FIG. 2, on the peripheral wall 2 above the piston 1, a first ring groove 5, a second ring groove 6 and an oil ring groove 7 are formed in this order from above.

Further, as shown in FIG. 1, a notch 9 is formed on the opening end side of the piston pin fitting hole 8, and below the notch 9, as shown in FIG. A flange 10 forming a part is formed.

On the other hand, as shown in FIG. 1, a sectional view taken along the line IV-IV in FIG. 1, and a sectional view taken along the line VV in FIG. 4, as shown in FIG. Outside the part G surrounded by the shaped skirts 3, 3 and the continuous walls 3 ', 3',
Moreover, at the four corners of the piston bottom surface 4 located outside the piston pin boss wall in which the piston pin insertion hole 8 is formed,
Oil holes are formed almost vertically from the bottom surface 4 of the piston.
11 are drilled at a total of 4 places, and an oil introduction hole 13 (FIGS. 3 and 4) communicating with a part of the oil ring groove 7 is drilled in a part 12 of the periphery of the oil hole 11. .

Incidentally, as shown in another embodiment of FIG. 5 in which the same portions as those of FIG. 4 are designated by the same reference numerals, a part 12 of the peripheral edge of the oil hole 11 communicates with a part of the oil ring groove 7. It may be formed as follows.

As shown in FIG. 1, the oil hole 11 formed substantially vertically from the piston bottom surface 4 can be easily formed from the bottom surface side of the piston 1 using a drill.

As shown in FIG. 1, the oil hole 11 is formed at a position outside the portion G surrounded by the pair of arc-shaped skirts 3 and 3 and the continuous walls 3'and 3 ', and the piston pin is inserted. Since it is the four corners of the piston bottom surface 4 which are located outside the piston pin boss wall in which the application hole 8 is formed, the diameter of the oil hole 11 can be formed larger than that of the conventional one, and its position can be changed. It can be formed at a predetermined pitch over the entire circumference of the piston 1. Further, the hole shape is not limited to a round hole and may be any shape.

Therefore, according to the piston 1 described above, in the embodiment shown in FIG. 4, the cooling oil scraped out by the oil ring groove 7 flows down into the oil hole 11 through the oil introduction hole 13, and in the embodiment shown in FIG. In the embodiment shown, the cooling oil flows directly into the oil hole 11.

Therefore, in any of the embodiments, the piston pin fitting hole 8 is formed outside the portion G surrounded by the pair of arc-shaped skirts 3 and 3 and the continuous walls 3'and 3 '. Piston bottom 4 located outside the piston pin boss wall
In addition, since the oil holes 11 are formed substantially vertically from the piston bottom surface 4, it is possible to secure a large diameter of the oil holes 11 to increase the flow amount of the cooling oil, and moreover, to drop from the oil holes 11. Since the cooling oil drops downward without being applied to the portion located below the portion G surrounded by the pair of skirts and the continuous wall, the cooling oil adheres to other parts such as the connecting rod and is consumed. It is possible to rapidly drop downward without increasing the amount and increase the recovery amount.

Further, according to the piston 1 described above, the bottom surface 4 of the piston 1 is simultaneously cooled by the cooling oil that flows down into the plurality of oil holes 11 having a large diameter formed in the piston bottom surface 4, and the cooling area is increased. It will be.

[Effect of device]

As described above, in the piston of the present invention, a pair of arc-shaped skirts facing each other and a portion surrounded by a continuous wall continuously formed so as to surround the pair of arc-shaped skirts are provided outside the part surrounded by the continuous walls. And the piston bottom surface located outside the piston pin boss wall in which the piston pin insertion hole is formed has oil that is substantially vertical from the piston bottom surface and part of the peripheral edge communicates with the oil ring groove of the piston. Since each hole is drilled so that the oil dropped only through the oil ring groove can be quickly dropped downward without hanging on other parts such as the connecting rod from each oil hole, the recovery efficiency of the cooling oil can be improved. Can be improved and the waste of oil can be significantly reduced. Further, since the oil hole is formed almost vertically from the bottom surface of the piston, the oil hole can be directly processed from the bottom surface side of the piston, and the oil hole can be easily processed. Also, since this oil hole is not formed in the piston pin boss wall, a large oil hole diameter can be secured without lowering the mechanical strength of each part of the piston, especially the piston pin boss wall where the piston pin fitting insertion hole is formed. The oil dropped only through the oil ring groove can be quickly dropped below the piston from the oil hole. Also, the cooling oil that drops from the oil hole drops downward without hitting other parts such as the connecting rod, so the cooling oil drops smoothly downward, thus reducing the oil consumption and recovering it. Can be further increased. Furthermore, since a large diameter oil hole is drilled on all of the bottom surface of the piston, the weight of the piston is further reduced, and the piston can be used for higher speed rotation.
The cooling oil passing through each oil hole also increases the piston surface area in contact with the cooling oil, so that the cooling efficiency of the piston can be further improved.

[Brief description of drawings]

FIG. 1 is a bottom view of a piston showing an embodiment of the present invention,
2 is a sectional view taken along line III-III in FIG. 1, FIG. 3 is a sectional view taken along line IV-IV in FIG. 1, and FIG. 4 is taken along VV in FIG. Sectional view cut, FIG. 5 is a conceptual sectional view showing another embodiment of the present invention, FIG. 6 is a bottom view of a piston having a conventional structure, and FIG. 7 is a sectional view taken along line II of FIG. 8 is a sectional view taken along line II-II in FIG. 1 ... Piston, 4 ... Piston bottom, 3 ... Skirt, 3 '... Continuous wall, 7 ... Oil ring groove, 8 ... Piston pin fitting hole, 11 ... Oil hole, G ... Pair The part surrounded by the arc-shaped skirt and continuous wall.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Bibliography Sho 59-96343 (JP, U) Steady opening 53-85409 (JP, U) Steady opening Sho 60-120242 (JP, U) Patent 175326 (JP, C1) Patent 140002 (JP, C2)

Claims (1)

[Scope of utility model registration request] 1. A pair of arc-shaped skirts 3, 3 facing each other having a short circumferential width, and a continuous wall 3 continuously formed so as to surround the pair of arc-shaped skirts 3, 3. In the piston 1 having 'and 3', a piston pin fitting hole is provided outside the portion G surrounded by the pair of arcuate skirts 3 and 3 and the continuous walls 3'and 3 '. An oil hole 11 is formed in the piston bottom surface 4 located outside the piston pin boss wall where 8 is formed. The oil hole 11 is substantially vertical from the piston bottom surface 4 and a part of the peripheral edge communicates with the oil ring groove 7 of the piston. Then, the cooling oil discharged from the oil hole 11 through the oil ring groove 7 is allowed to drop downward without being applied to the portion located below the portion G surrounded by the pair of skirts and the continuous wall. West Piston, characterized in that.