JP-2026075443-A - Pistons, internal combustion engines, and vehicles

JP2026075443AJP 2026075443 AJP2026075443 AJP 2026075443AJP-2026075443-A

Abstract

[Problem] To provide a piston capable of reducing the rigidity of the piston skirt in a configuration in which an oil passage is formed. [Solution] The piston comprises a piston head, a piston skirt, and an oil passage. The piston skirt is located on the bottom side relative to the piston head, and a pin hole is formed in the piston skirt along an extending direction intersecting the vertical direction. The oil passage extends through the piston head and piston skirt and has an opening in the piston skirt that opens towards the bottom side. The dimensions of the opening along the extending direction of the pin hole are larger than the dimensions of the opening along the width direction intersecting both the vertical direction and the extending direction of the pin hole. [Selection Diagram] Figure 2

Inventors

岡▲崎▼ 一也

Assignees

いすゞ自動車株式会社

Dates

Publication Date: 20260508
Application Date: 20241022

Claims (7)

Piston head and, A piston skirt is provided on the bottom side of the piston head and has pin holes formed along an extension direction that intersects the vertical direction, An oil passage extending through the piston head and the piston skirt, having an opening in the piston skirt that opens toward the bottom, wherein the dimensions of the opening along the extending direction of the pin hole are larger than the dimensions of the opening along the width direction intersecting both the vertical direction and the extending direction of the pin hole, A piston equipped with
The piston according to claim 1, wherein at the opening edge of the oil passage, the radius of curvature of the portion of the pin hole that contacts the opening from the width direction is larger than the radius of curvature of the portion of the pin hole that contacts the opening from the extension direction.
The piston according to claim 2, wherein the opening of the oil passage is formed in an elliptical shape with its major axis aligned with the extending direction of the pin hole.
The oil passage has a cooling chamber formed inside the piston head, and a connecting passage between the opening and the cooling chamber. The opening is formed coaxially with the connecting path. The piston according to claim 1.
The piston according to claim 1, wherein the opening forms an inlet through which oil from the oil jet flows into the oil passage.
A piston according to any one of claims 1 to 5, An oil jet capable of spraying oil and directing the sprayed oil into the oil passage of the piston, An internal combustion engine equipped with the following features.
A vehicle equipped with the internal combustion engine of claim 6.

Description

This invention relates to pistons, internal combustion engines, and vehicles. In internal combustion engines used in vehicles, the piston reciprocates vertically within the cylinder's internal cavity, converting this reciprocating motion into rotational motion of the crankshaft. The piston skirt has a pinhole through which a piston pin is inserted. In internal combustion engines, the connecting rod is connected to the piston via the piston pin. Furthermore, some internal combustion engines have oil jets attached to the cylinders, which inject oil towards the piston. In such internal combustion engines, the piston is cooled by the oil from the oil jets. Also, in internal combustion engines equipped with oil jets, an oil passage is formed inside the piston, allowing the oil injected from the oil jets to flow into the oil passage. In pistons with an oil passage, the oil inlet from the oil jets is formed as an opening on the bottom side in the piston skirt. Japanese Utility Model Publication No. 62-122155 Figure 1 is a schematic cross-sectional view showing an example of the configuration of a piston 3 and its vicinity in an internal combustion engine according to an embodiment.Figure 2 is a schematic diagram of the piston shown in Figure 1, viewed from the bottom.Figure 3 is a schematic cross-sectional view showing an example piston from Figure 1, but with a different cross-sectional view than that of Figure 1.Figure 4 is a schematic diagram of the piston in the example shown in Figure 1, showing the opening that forms the oil passage inlet and the surrounding area as viewed from the bottom side.Figure 5 is a schematic diagram of the opening forming the oil passage inlet and the surrounding area of a piston according to a certain modified example, viewed from the bottom side.Figure 6 is a schematic diagram of a piston according to a different modification from Figure 5, showing the opening that forms the oil passage inlet and the surrounding area as viewed from the bottom side.Figure 7 is a schematic cross-sectional view showing a piston according to a different modification from that shown in Figures 5 and 6.Figure 8 is a schematic diagram showing an example of the configuration of a vehicle equipped with an internal combustion engine according to the embodiment. The embodiments will be described below with reference to the drawings. An internal combustion engine installed in a vehicle or the like has one or more pistons and the same number of cylinders as pistons. Each of the one or more pistons reciprocates vertically within a corresponding internal cavity of one of the cylinders. For example, a four-cylinder internal combustion engine has four pistons and four cylinders, and each of the four pistons reciprocates within a corresponding internal cavity of one of the four cylinders. In an internal combustion engine, each of the one or more pistons is connected to the crankshaft via a connecting rod. The reciprocating motion of the one or more pistons rotates the crankshaft; that is, the reciprocating motion of the pistons is converted into the rotational motion of the crankshaft. In this embodiment, one or more of the pistons in the internal combustion engine have the configuration described below. Furthermore, the configuration described below is applicable to both diesel engines and gasoline engines. Figure 1 is a schematic cross-sectional view showing an example of the configuration of a piston 3 and its vicinity in an internal combustion engine 1 according to an embodiment. As shown in Figure 1, the internal combustion engine 1 comprises a cylinder 2 and a piston 3. The internal combustion engine 1 and piston 3 have defined vertical directions (directions indicated by arrows Y1 and Y2) and longitudinal directions (direction indicated by arrow Z) that intersect (orthogonal or nearly orthogonal to) the vertical directions. Figure 1 shows cross-sections along both the vertical and longitudinal directions. In the internal combustion engine 1 and piston 3, one side in the vertical direction is referred to as the top side (arrow Y1 side), and the side opposite the top side in the vertical direction is referred to as the bottom side (arrow Y2 side). The cylinder 2 is formed in a cylindrical shape with its central axis aligned vertically, and a piston 3 is positioned within the internal cavity of the cylinder 2. The piston 3 reciprocates vertically within the internal cavity of the cylinder 2. Therefore, the vertical direction is also referred to as the direction of reciprocating motion of the cylinder 2, and the direction of movement of the cylinder 2. In the internal combustion engine 1, an intake port and an exhaust port (neither shown) are located on the top side relative to the piston 3. Within the internal cavity of the cylinder 2, a combustion chamber is formed by the space between the intake port, the exhaust port, and the piston 3. Furthermore, in the internal combustion engine 1, a crankshaft (not shown