JP2004285989A - Structure of oil drain opening of oil pan - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure of an oil drain opening for restraining a residual volume to the utmost at the time of oil drain, and preventing discharging speed from becoming slow by making a projection volume from an oil pan bottom as small as possible for securing a ground height. <P>SOLUTION: A boss (2) is projected to an oil pan bottom face (1b) inwardly, and a screw hole (2a) is bored to the boss (2) to form a drain port (D). A slit-like groove (3) whose tip end is communicated in the screw hole (2a), and which is opened sideward and upward of the boss is provided to the boss (2). A communication hole (4) penetrating through a bottom of the slit-like groove (3) from an inner face of the screw hole (2a) is bored diagonally upward from a lower part of the drain port (D). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a structure of an oil drain port provided at an oil pan bottom of an internal combustion engine.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a drain port for discharging oil for oil change or the like is provided at the bottom of an oil pan of an internal combustion engine (hereinafter referred to as an engine), and is closed with a screw plug (drain plug) or the like. It is necessary for this drain port to minimize the residual oil discharge, and the oil pan, including the drain plug, is connected to the ground or floor (or structure) below it. It is necessary to secure a distance or a space, and particularly in a vehicle engine, securing a ground clearance (indicated by H in FIG. 1) to avoid interference with the ground during traveling is an important requirement.
[0003]
The oil pan is usually made of a sheet metal or a cast product, and is formed to be thin.The oil drain port is formed by forming a boss at the bottom of the oil pan and providing a boss to secure the length of the screw portion of the drain plug. ing.
The boss can be formed so as to be able to be discharged without leaving oil unless the boss is projected outward (downward) of the oil pan and is not projected inside. However, as described above, if the boss is formed to protrude inward to minimize the protrusion from the lower surface of the oil pan in order to secure the ground clearance, the boss portion becomes a bank for the screw hole of the drain port. Oil cannot be completely discharged.
[0004]
In addition, as a conventional technology, a drain port is provided at each end in the front-back direction and the left-right direction with respect to a general-purpose engine mounted on various types of machines, and the oil pan is mounted in different positions in the front-rear direction. It has been proposed to avoid a structure or the like by making it possible to select an oil pan and to provide a recess at the bottom of an oil pan for guiding oil discharge toward a drain port (see Patent Document 1).
[0005]
However, according to the present invention, a horizontal drain port is formed in the side of the oil pan, and a recess is provided to guide discharge and prevent residual oil. ing. Further, the position of the horizontal drain port is changed according to a change in the residual oil level (indicated by L in FIG. 1) in the oil pan, so that the oil receiving container needs to be moved or a large receiving pan is required. Have to be used.
[0006]
[Patent Document 1]
Japanese Patent No. 3,208,477
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION The present invention addresses the above-described problems, and secures a ground clearance by minimizing the amount of protrusion from the bottom of an oil pan, as well as minimizing the remaining amount at the time of oil draining, and further reducing the drain speed. It aims to provide a mouth structure.
[0008]
[Means for Solving the Problems]
According to the present invention, in the structure of the oil drain port which is bored downward at the bottom of the oil pan of the internal combustion engine, the boss (2) is protruded inward on the bottom surface (1b) of the oil pan, and the boss (2) is formed. ), A drain hole (D) is formed by drilling a screw hole (2a), and the boss (2) has a distal end portion communicating with the screw hole (2a) and laterally and upwardly of the boss (2). A slit-shaped groove (3) that is open to the outside is provided (claim 1).
[0009]
With this configuration, the oil in the oil pan is discharged even through the leading end of the groove communicating with the screw hole, and the level of residual oil can be reduced from the upper surface of the boss to the bottom of the groove.
[0010]
Further, according to the present invention, in the structure of the oil drain port which is bored downward at the bottom of the oil pan of the internal combustion engine, the boss (2) is protruded inwardly on the bottom surface (1b) of the oil pan, and the boss is provided. A drain hole (D) is formed by piercing a screw hole (2a) in (2), and a boss outer peripheral portion is formed obliquely upward from below the drain hole (D) from the inner surface of the screw hole (2a). A communication hole (4) penetrating through (S) is formed (claim 2).
[0011]
With such a configuration, oil is also discharged from the communication hole penetrating the boss, and the level of residual oil falls below the upper surface of the boss and becomes the height of the penetrating end of the communication hole. In addition, the oil discharge speed at that portion is determined by the cross-sectional area of the communication hole. However, it is possible to solve the problem of strength and eliminate the need for time.
[0012]
Further, according to the present invention, a communication hole (4) penetrating from the inner surface of the screw hole (2a) to the bottom of the slit-shaped groove (3) is formed obliquely upward from below the drain port (D). (Claim 3).
[0013]
With this configuration, the level of residual oil is lowered to the bottom of the groove, and the oil discharge speed is improved by the communication hole.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In FIG. 1, the engine is mounted on the vehicle at an angle (FIG. 1 shows a cross section of an oil pan perpendicular to the crankshaft, that is, in this example, the engine is inclined at a right angle to the crankshaft). The bottom surface 1b of the oil pan 1 attached to the lower surface of a cylinder block (not shown) is formed so as to be substantially parallel to the ground G when the engine is mounted. A boss 2 is provided on the bottom surface 1b so as to protrude inward. A screw hole 2a is formed in the boss 2 in a vertical direction to form a drain port D.
[0015]
Further, referring also to FIG. 2 (a view as viewed from the direction indicated by the arrow A in FIG. 1), the boss 2 is provided above and to the side of the boss such that the tip end communicates with the screw hole 2a of the drain port as shown in the figure. An open slit-like groove 3 is formed.
This groove 3 may be formed by cutting, but is preferably formed (cast) from a rough material.
[0016]
For example, in the illustrated example, the width of the groove 3 is about 3 mm with respect to the diameter of the screw hole 2a of 16 mm. As shown in detail in FIG. Parallel, the vertical end face 3a of the groove is perpendicular to the oil pan mounting surface B (the direction in which the mold is removed), and the intersection is formed at a slightly acute angle so that the height h = about 2 to 3 mm in the screw hole 2a. I try to communicate.
[0017]
Since the tip of the groove 3 is open in the screw hole 2a as described above, it is not preferable to provide a large number of grooves or to make the width too large in view of strength.
With such a configuration, the level of residual oil in the oil pan 1 drops from the upper surface of the boss 2 to the bottom 3 b of the groove 3.
[0018]
Next, returning to FIG. 1, the boss 2 is formed with a communication hole 4 penetrating from the inner surface of the screw hole 2 a to the outer peripheral portion indicated by the symbol S from the inner surface of the screw hole 2 a obliquely upward from below the drain port D. It communicates with the bottom.
[0019]
It is preferable that the end of the communication hole 4 penetrates as much as possible below the outer peripheral portion S of the boss 2 (residual oil is small). However, drilling from the inner diameter of the screw hole 2a has processing limitations. In addition, there is also a condition for maintaining oil tightness when the drain plug 5 is screwed, and in the illustrated example, the inclination angle θ is about 50 to 60 °. Further, it is preferable that the diameter d is large (the oil draining time is shortened), but there are also restrictions on processing and strength, and in this example, the diameter d is about 5 mm.
[0020]
As described above, in the present embodiment, the level of residual oil is reduced by forming the slit-shaped groove 3 by die-cutting, which is easy to manufacture, on the boss 2 protruding inward of the oil pan 1, and the communication hole 4 The discharge speed can be secured, and most of the oil can be drained.
[0021]
【The invention's effect】
The functions and effects of the present invention are summarized as follows.
(1) There is no protrusion of the boss below the bottom surface of the oil pan, and a ground clearance or space below the boss can be secured.
(2) Most of the oil in the oil pan can be discharged, and the discharge speed is sufficiently practical. Further, the drain port is directed downward, and can be easily discharged to the oil receiving container.
(3) It is easy to manufacture.
[Brief description of the drawings]
FIG. 1 shows a cross section including a drain port of an oil pan according to the present invention.
FIG. 2 is a view taken in the direction of arrow A in FIG. 1;
FIG. 3 is a detailed view of a slit-like groove.
[Explanation of symbols]
1 oil pan 1b oil pan bottom 2 boss 2a screw hole (drain port)
3 ... Groove 4 ... Communication hole D ... Drain port

Claims (3)

In the structure of the oil drain port drilled downward at the bottom of the oil pan of the internal combustion engine, a boss is projected inward on the bottom of the oil pan, and a screw hole is drilled in the boss to form a drain port. An oil drain port structure, wherein the boss is provided with a slit-like groove having a leading end communicating with the inside of the screw hole and open to the side and upward of the boss. In the structure of the oil drain port drilled downward at the bottom of the oil pan of the internal combustion engine, a boss is projected inward on the bottom of the oil pan, and a screw hole is drilled in the boss to form a drain port. A communication hole penetrating from an inner surface of the screw hole to an outer peripheral portion of the boss so as to extend obliquely upward from below the drain port. 2. The structure of the oil drain port according to claim 1, wherein a communication hole penetrating from the inner surface of the screw hole to the bottom of the slit-shaped groove is formed obliquely upward from below the drain port.

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