JP7294201B2 - Drain structure - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to a drain structure, and more particularly to a technology suitable for the drain structure of an oil pan.

For example, in Patent Documents 1 and 2, a drain hole for discharging oil is formed through the bottom of an oil pan that stores oil, and an inner cylindrical portion protruding from the opening peripheral edge of the drain hole to the inside of the oil pan. is provided, and the drain hole is closed by screwing the male threaded portion of the drain plug into the female threaded portion formed on the inner peripheral surface of the inner cylindrical portion from the outside of the oil pan. .

JP 2002-054416 A JP-A-59-019798

In the above drain structure, when the drain plug is removed and the oil is drained from the drain hole, part of the oil discharged from the drain hole flows along the outer wall surface of the oil pan, causing the oil to flow downward. may drip down.

In order to prevent such dripping, the bottom wall of the oil pan is burred, as in the structure described in Document 2 above, so that the periphery of the opening of the drain hole is positioned outside the outer wall surface of the oil pan. It is preferable to make it protrude. However, if the opening edge of the drain hole protrudes, the flange portion of the drain plug interferes with the opening edge of the drain hole when the drain plug is screwed, which may lead to a deterioration in sealing performance.

The technique of the present disclosure has been made in view of the above circumstances, and aims to improve sealing performance while effectively suppressing dripping of oil (liquid) discharged from a drain hole.

The technology of the present disclosure is a drain structure for a tank that stores liquid, which includes a drain hole formed through a wall of the tank, and a drain hole surrounding an opening peripheral edge of the drain hole and extending outside the wall surface of the tank. a protruding outer cylindrical portion; and a fastened portion provided on either the inner peripheral surface of the inner cylindrical portion protruding from the drain hole to the inside of the tank or the inner peripheral surface of the outer cylindrical portion; An annular seal member having a through-hole for inserting the outer cylindrical portion and having an axial length longer than a protruding length of the outer cylindrical portion from the wall surface, and is fastened to the fastened portion. and a plug member that has a fastening portion and is seated on the annular seal member to close the drain hole.

Further, the fastening part is a female threaded part, and the plug member is a drain plug having a male threaded part as the fastening part that is screwed with the female threaded part, and a flange part that is seated on the annular seal member. is preferred.

Moreover, it is preferable that the outer tubular portion is formed integrally with a wall portion of the tank through which the drain hole passes.

Further, it is preferable that the tank is an oil pan.

According to the technique of the present disclosure, it is possible to effectively suppress dripping of oil (liquid) discharged from a drain hole and improve sealing performance.

It is a typical longitudinal section showing an oil pan concerning this embodiment. 2 is a schematic exploded perspective view showing a drain structure according to this embodiment; FIG. 4 is a schematic vertical cross-section showing the drain structure according to the embodiment; 4 is a schematic vertical cross-section showing a drain structure according to another embodiment;

The drain structure according to this embodiment will be described below with reference to the accompanying drawings. The same parts are given the same reference numerals, and their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

[overall structure]
FIG. 1 is a schematic longitudinal sectional view showing an oil pan 10 according to this embodiment.

As shown in FIG. 1, the oil pan 10 (an example of the tank of the present disclosure) is provided, for example, in the lower part of the crankcase C of the engine E, and is supplied to each lubricating element of the engine E. Engine oil (hereinafter referred to as , simply oil). Note that the oil pan 10 may be an oil pan that stores oil for a transmission, a clutch device, a differential gear device, or the like. Further, application of the present disclosure is not limited to an oil pan, and may be applied to a lower tank of a radiator that stores cooling water, or the like.

The oil pan 10 includes a bottom wall portion 11, a side wall portion 12 extending upward from the peripheral edge of the bottom wall portion 11, and an inclined wall portion 13 connecting the bottom wall portion 11 and the side wall portion 12 obliquely to each other. A flange plate portion 14 projecting outward from the upper end of the side wall portion 12 is provided.

The flange plate portion 14 is provided with a plurality of bolt insertion holes. The oil pan 10 is attached to the engine E by inserting a bolt 15 into the bolt insertion hole and screwing the bolt 15 into a female screw hole of the crankcase C. As shown in FIG.

The inclined wall portion 13 of the oil pan 10 is provided with the drain structure 20 of the present disclosure. Although the drain structure 20 may be provided on the bottom wall portion 11 or the side wall portion 12 , if the drain structure 20 is provided on the inclined wall portion 13 , the amount of downward protrusion is reduced compared to the structure provided on the bottom wall portion 11 . Therefore, it is possible to effectively secure the minimum ground clearance. Further, if the drain structure 20 is provided on the inclined wall portion 13, the amount of protrusion to the side can be suppressed compared to the structure provided on the side wall portion 12, and the degree of freedom in peripheral layout can be ensured.

Details of the drain structure 20 according to the present embodiment will be described below.

[Drain structure]
FIG. 2 is a schematic exploded perspective view showing the drain structure 20 according to this embodiment, and FIG. 3 is a schematic longitudinal section showing the drain structure 20 according to this embodiment.

As shown in FIGS. 2 and 3, the drain structure 20 includes a drain hole 21, an inner tubular portion 22, an outer tubular portion 24, an annular seal member 26, and a drain plug 27 (an example of a plug member). and

The drain hole 21 is a circular hole penetrating the inclined wall portion 13 of the oil pan 10 and drains the oil from the inside of the oil pan 10 . The hole diameter of the drain hole 21 may be larger than the outer diameter of the shaft portion 27A of the drain plug 27, which will be described later.

The inner cylindrical portion 22 is formed in a substantially cylindrical shape surrounding the periphery of the opening of the drain hole 21 and arranged concentrically with the drain hole 21 . The inner cylindrical portion 22 protrudes inside the oil pan 10 by fixing a base end portion 23 ( FIG. 3 ) thereof to the inner peripheral surface of the inclined wall portion 13 by welding or the like.

As shown in FIG. 3 , an oil discharge groove 23</b>A communicating with the drain hole 21 is recessed in the base end portion 23 of the inner cylindrical portion 22 . The oil discharge groove 23A functions to send oil remaining on the bottom side of the oil pan 10 to the drain hole 21 when the oil is discharged. A female threaded portion 22A (fastened portion) that screws together with a male threaded portion 27B (fastened portion) of the drain plug 27 is provided on the inner peripheral surface of the inner tubular portion 22 .

The outer tubular portion 24 is formed in a substantially cylindrical shape surrounding the periphery of the opening of the drain hole 21 and protrudes outward from the outer wall surface of the inclined wall portion 13 . The outer tubular portion 24 is preferably formed as a projecting hole integral with the drain hole 21 by burring the inclined wall portion 13 from the inside. When the outer cylindrical portion 24 is integrally formed with the drain hole 21 by burring in this manner, the base end side of the outer cylindrical portion 24 and the opening peripheral edge of the drain hole 21 are connected by the smooth curved surface portion 25 . become.

The annular seal member 26 is formed of copper or the like in a substantially annular shape, and has a through hole 26</b>A having a larger diameter than the outer diameter of the outer tubular portion 24 . More specifically, the hole diameter of the through hole 26A is formed to be larger than the outer diameter of the curved outer side of the curved surface portion 25, and when the drain plug 27 described later is screwed, the annular seal member 26 is formed on the inclined wall portion. It is constructed so that it can be surely seated on the outer wall surface of 13.

Further, the axial length (thickness) of the annular seal member 26 is formed longer than the projection length (height) of the outer tubular portion 24 from the inclined wall portion 13 . That is, when the drain plug 27 is screwed, the annular seal member 26 is sandwiched between the outer wall surface of the inclined wall portion 13 and the flange portion 29 of the drain plug 27 in a press-contact state. As a result, interference between the projecting edge of the outer cylindrical portion 24 and the flange portion 29 can be prevented, and the sealing performance can be reliably improved.

The drain plug 27 includes a substantially hexagonal columnar head portion 28, a flange portion 29 having a larger diameter than the head portion 28 and the through hole 26A of the annular seal member 26, and a projection from the flange portion 29 to the side opposite to the head portion 28. and a shaft portion 27A. An outer peripheral surface of the shaft portion 27A is provided with a male thread portion 27B that is screwed with the female thread portion 22A.

That is, when the male threaded portion 27B of the drain plug 27 is screwed into the female threaded portion 22A of the inner cylindrical portion 22, the flange portion 29 of the annular seal member 26 presses against the outer wall surface of the inclined wall portion 13, thereby closing the drain hole 21. It can be closed.

According to the drain structure 20 of the present embodiment described in detail above, the outer cylindrical portion 24 that protrudes outward from the outer wall surface of the inclined wall portion 13 is provided at the opening peripheral edge of the drain hole 21 . As a result, when removing the drain plug 27 and draining the oil, the oil discharged from the drain hole 21 can be prevented from flowing along the outer wall surfaces of the inclined wall portion 13 and the bottom wall portion 11. It is possible to effectively prevent the downward dripping of the

Further, by forming the axial length of the annular seal member 26 longer than the projecting length of the outer cylindrical portion 24, interference between the flange portion 29 of the drain plug 27 and the outer cylindrical portion 24 can be effectively prevented. is configured as As a result, it is possible to effectively prevent the formation of a gap between the annular seal member 26 and the flange portion 29 or between the annular seal member 26 and the outer wall surface of the inclined wall portion 13, thereby improving the sealing performance. You can definitely improve.

[others]
It should be noted that the present disclosure is not limited to the above-described embodiments, and can be appropriately modified and implemented without departing from the gist of the present disclosure.

For example, as shown in FIG. 4, the outer tubular portion 24 is formed as a separate member from the oil pan 10, and the base end side peripheral edge of the outer tubular portion 24 is joined to the oil pan 10 by welding or the like. You may Also in this case, the same effects as those of the above-described embodiment can be obtained. Further, although the female threaded portion 22A has been described as being provided on the inner tubular portion 22, the female threaded portion 22A may be provided on the inner peripheral surface of the outer tubular portion 24 as well. Further, the fastening structure between the drain plug 27 and the inner tubular portion 22 is not limited to the female threaded portion 22A and the male threaded portion 27B, and other fastening structures may be used.

10 oil pan (tank)
11 bottom wall (wall)
12 side wall (wall)
13 Inclined wall (wall)
20 drain structure 21 drain hole 22 inner cylindrical portion 22A female screw portion (fastened portion)
24 outer tubular portion 26 annular seal member 26A through hole 27 drain plug (plug member)
27A shaft portion 27B male thread portion (fastening portion)
28 head portion 29 flange portion

Claims (4)

A drain structure for a tank that stores liquid,
a drain hole penetrating through an inclined wall portion that obliquely connects the bottom wall portion and the side wall portion of the tank;
an outer cylindrical portion that surrounds the periphery of the opening of the drain hole and protrudes outward from the wall surface of the tank;
a fastened portion provided on an inner peripheral surface of an inner cylindrical portion protruding from the drain hole to the inside of the tank;
an annular seal member having a through hole into which the outer cylindrical portion is inserted and having an axial length longer than a projection length of the outer cylindrical portion from the wall surface;
a plug member that has a fastening portion that is fastened to the fastening portion and that sits on the annular seal member to close the drain hole ;
A discharge groove communicating with the drain hole for discharging the liquid is provided at the proximal end of the inner cylindrical portion,
A drain structure characterized by: In addition, the tightened portion is a female threaded portion, and the plug member is a drain plug having a male threaded portion as the fastening portion that screws together with the female threaded portion, and a flange portion that is seated on the annular seal member. Item 1. The drain structure according to item 1. 3. The drain structure according to claim 1, wherein the outer tubular portion is integrally formed with a wall portion of the tank through which the drain hole penetrates. The drain structure according to any one of claims 1 to 3, wherein the tank is an oil pan.

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