JPS6315532Y2 - - Google Patents

Description

[Detailed description of the invention] (Technical field) This invention relates to an improvement of a damping steel oil pan for an internal combustion engine.

(Background technology) The oil pan attached to the bottom of the cylinder block is manufactured by press-molding a thin steel plate, but due to the vibration of the cylinder block, the surface of the oil pan vibrates, which becomes a source of vibration noise. Ta. Therefore, as shown in Figs. 1 and 2, there is a structure in which the oil pan body 4 is formed of a damping steel plate in which a viscoelastic body 2 is sandwiched and bonded between two thin steel plates 1A and 1B in a sandwich-like manner (for example, Utsukai Showa 58-
Publication No. 30707).

Incidentally, a drain nut 5 for draining lubricating oil is attached to the bottom of the oil pan body 4, and the drain nut 5 is conventionally fitted into a mounting hole 6 (punched hole) formed in the oil pan body 4, as shown in the figure. and fixed by welding.

Reference numeral 7 indicates a drain plug that is screwed into the drain hole 8 of the drain nut 5 and seals the drain hole 8 oil-tightly through a seal 9.

In this case, the drain nut 5 is the oil pan body 4.
On the other hand, thin steel plates 1A and 1 are connected through welded parts 10 and 11.
However, since the viscoelastic body 2 does not form a welded part, the welded surface of the drain nut 5 cannot be sufficiently secured, and therefore the welded parts 10 and 11 are connected to the drain plug 7.
The product may not be able to withstand the tightening force and may be damaged.

Incidentally, in order to increase the welding strength of the drain nut 5, it would be sufficient to enlarge the welded parts 10 and 11, but there is a fear that the viscoelastic body 2 will melt due to the heat during welding, so it is necessary to enlarge the welded parts 10 and 11. There are also limits.

Furthermore, when welding the drain nut 5, since the viscoelastic body 2 between the two thin steel plates 1A and 1B is an insulator, it is impossible to electrically connect the steel plates 1A and 1B with a conductor such as a clamp. There was also the problem that it was necessary.

(Purpose of the invention) This invention was made with attention to these problems, and the purpose is to provide a drain nut mounting structure that can withstand sufficient tightening torque to ensure sufficient sealing performance. .

(Means for solving the problem) In order to achieve the above object, in this invention, the drain nut mounting hole is opened to a smaller diameter than the inner edge of the hole in one thin-walled steel plate, and the inner edge of the hole in the other thin-walled steel plate is shaped like a flange. The bent steel plate is bent to overlap with the inner edge of the hole of the other thin steel plate, and then in this bent overlapping part,
The stepped portion of the drain nut, consisting of a large diameter portion that sits on the periphery of the mounting hole and a small diameter portion that fits into the mounting hole, was fixed by welding.

(Example) Hereinafter, this invention will be explained according to an example shown in FIGS. 3 and 4. Note that the same parts as in FIGS. 1 and 2 are designated by the same reference numerals.

A mounting hole 13 is formed in the bottom of the oil pan body 12 made of a damping steel plate.

As shown in FIGS. 4a and 4b, the mounting hole 13 is formed by drilling a relatively small diameter hole in one of the thin steel plates 1A by the bending allowance 14, and then punching the bending allowance 14 using a punch 15 and a die 16. the other thin steel plate 1B
It is formed by bending so as to overlap the inner edge of a relatively large diameter hole.

That is, in the mounting hole 13, a flange portion 17 is formed by the bending allowance 14 to connect the two thin steel plates 1A and 1B.

Then, the drain nut 5 is fitted into the mounting hole 13 and fixed by welding. In this case, the drain nut 5 has a stepped shape consisting of a large diameter section that seats on the periphery of the mounting hole 13 and a small diameter section that fits into the mounting hole 13, and the drain nut 5 has a stepped shape that is made up of a large diameter section that seats on the periphery of the mounting hole 13 and a small diameter section that fits into the mounting hole 13. It is fixed to the surface of the thin steel plate 1A and the peripheral surface of the flange part 17 by the portion 18, and to the thin steel plates 1A and 1B by the welded portion 19 provided around the end face of the small diameter portion, respectively.

7 is a drain plug, and 9 is its seal.

In this way, since the flange portion 17 is formed in the mounting hole 13 by the bending allowance 14 of the thin steel plate 1A and serves as a welding surface, the welding surface of the drain nut 5 can be larger than in the conventional case, and therefore the drain nut 5 can be It is securely fixed to the oil pan body 12 and has a welding strength sufficient to withstand the tightening force of the drain plug 7.

Moreover, the thin steel plates 1A and 1B have flange portions 17
Since they are connected through the welding process, there is an advantage in terms of workability that electrical conductors such as clamps are not required during welding.

Incidentally, it is not necessary to weld one side as long as the welding strength that can withstand the tightening force of the drain plug 7 can be ensured in one welded part 19 as shown in FIG.

In addition, as shown in FIG. 6, when forming the mounting hole 13, as the bending allowance 14 of one thin steel plate 1A is bent, the inner edge of the other thin steel plate 1B overlaps the bending allowance 14 and is slightly bent. It's okay to be beaten.

(Effects of the invention) In summary, according to this invention, a flange portion is formed in the mounting hole by bending the inner edge of one thin steel plate so as to overlap the inner edge of the hole of the other thin steel plate, so that the drain nut can be attached to the drain plug. The welding strength is strong enough to withstand the tightening force of 100 lbs., and it can be firmly fixed.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a conventional oil pan, Fig. 2 is a sectional view of part A thereof, Fig. 3 is a sectional view of the main part corresponding to Fig. 2, showing an embodiment of this invention, Fig. 4 a, b
5 is an explanatory diagram of the process of machining the mounting hole, and FIGS. 5 and 6 are sectional views of main parts showing other embodiments. 1A, 1B... Thin steel plate, 2... Viscoelastic body, 5
...Drain nut, 12...Oil pan body, 1
3...Mounting hole, 17...Flange part.

Claims (1)

[Scope of utility model registration request] The oil pan body is formed by a vibration-damping steel plate with a viscoelastic material sandwiched between two thin steel plates in a sanderch-like shape, and a drain nut is fitted into a mounting hole formed at the bottom of the oil pan body and welded to the internal combustion engine. In an engine oil pan, the mounting hole is formed by opening the inner edge of the hole in one thin steel plate to a smaller diameter than the inner edge of the hole in the other thin steel plate, bending it into a flange shape, and overlapping the inner edge of the hole in the other thin steel plate. An oil pan for an internal combustion engine, characterized in that a stepped part of a drain nut consisting of a large diameter part that seats on the periphery of the mounting hole and a small diameter part that fits in the mounting hole is welded and fixed to this bent and overlapping part.