JP3918456B2 - Oil pan structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure of an oil pan attached to a lower part of a cylinder block of an internal combustion engine, and more particularly to a structure of a double structure oil pan.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an internal combustion engine has many sliding parts and heating parts, and has an oil circulation system for lubrication and cooling of these parts, and an oil pan that forms an oil reservoir at the lowest part of the oil circulation system. Usually, the oil pan is bolted to the lower part of the cylinder block, and is formed as a deep plate-shaped sheet metal member to ensure strength and heat dissipation.
By the way, in order to reduce the weight of oil pans as part of the weight reduction of vehicle bodies, the adoption of resin-molded oil pans and aluminum alloy oil pans is being studied. Is supplied to the market.
[0003]
[Problems to be solved by the invention]
However, when an oil pan made of resin or aluminum alloy is used, it is suitable for weight reduction, but the oil pan is often deployed at the bottom of the vehicle body, and it is subject to chipping caused by hopping when driving, curbs, etc. In such a case, there is a possibility of cracking damage, and in such a case, oil leakage occurs, and serious troubles such as engine seizure will occur if the vehicle runs without notice.
Therefore, when a resin oil pan is employed, a metal or resin under cover may be provided below the oil pan, but this is not preferable in terms of weight reduction.
[0004]
In addition, although the oil pan of a double wall structure is disclosed by Unexamined-Japanese-Patent No. 2000-18094, an inner member is covered with the outer member which comprises a sound-insulating wall, and sound insulation is ensured, the whole shape enlarges, There is a problem that the ground clearance becomes lower and the frequency of securing a mounting space and climbing a stone curb increases. Further, Japanese Patent Laid-Open No. 7-26929 discloses that an inner pan made of resin is disposed inside the oil pan, and the upper edge of the inner pan is brought into contact with several locations on the inner wall surface of the oil pan through a plurality of rubber pieces. An oil pan having a double structure is disclosed. However, this obtains the function of preventing the spread of engine noise by the oil layer between the oil pan and the inner pan, and the inner pan does not have the function of preventing oil leakage when the oil pan is broken.
[0005]
Based on the above-described problems, the present invention is an oil pan that suppresses oil leakage even if it is subjected to chipping or cracking damage while the vehicle is running, and prevents serious failures such as engine seizure, while suppressing the increase in size of the outer shape. The purpose is to provide a structure.
[0006]
[Means for Solving the Problems]
The invention according to claim 1 is a connecting flange that is overlapped and bolted from below to a mounting flange on the lower peripheral edge of a cylinder block of an internal combustion engine, and a deep dish portion that is bent and extended from the inner end of the oil pan of the connecting flange. In the structure of the oil pan having a drain portion protruding inwardly and having a drain hole formed therein, a clamping flange portion that is sandwiched between the mounting flange and the connecting flange and is bolted to form an annular shape. A flexible inner member having a bag-like portion extending from the pressure flange portion and excluding the opening facing the drain portion, and laid so as to be able to bend and displace on the entire inner wall surface of the oil pan. It is characterized by that.
As described above, since the inner wall surface of the oil pan has a bag-like portion that is laid so as to be able to bend and displace alone, a flexible inner member is provided, so that the oil pan is cracked or damaged by an external impact. However, at that time, the flexible inner member bends and displaces alone, avoids cracks and breakage, suppresses the enlargement of the outer shape, prevents oil leakage, and causes serious damage such as seizure of the engine body. Failure can be prevented.
[0007]
Preferably, the oil pan may be made of resin or aluminum alloy. In this case, the weight of the oil pan can be reduced.
Preferably, the flexible inner member may be formed of a film material or a soft synthetic resin material. When the inner member is molded with a film material or soft synthetic resin material in this way, the inner member can be reliably displaced and displaced when the oil pan cracks or breaks, preventing damage to the inner member and preventing oil leakage. it can.
[0008]
According to a second aspect of the present invention, in the structure of the oil pan according to the first aspect, an annular sealing surface is formed on the outer peripheral edge of the drain portion so as to be closely joined to the peripheral edge of the opening of the inner member.
Thus, since the periphery of the opening of the inner member to the annular sealing surface of the drain portion can be tightly joined, to prevent the penetration into the gap between the oil pan and the inner member of the oil, improving workability in oil change it can.
[0009]
Preferably, the annular sealing surface of the drain part is formed so as to be tightly joined to the periphery of the opening and to be able to attach a seal locking member that restricts the deviation of the periphery of the opening. In this case, since the shift of the peripheral edge of the opening is restricted by the seal locking member, the state in which the annular seal surface is closely joined to the peripheral edge of the opening is stable, and the gap between the oil pan of the oil and the inner member is stable. Can be reliably prevented, the workability at the time of oil change can be improved, and the displacement of the inner member in the oil pan can be reliably prevented.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
1 and 4 show an oil pan 1 to which an oil pan structure as an embodiment of the present invention is applied. The oil pan 1 is integrally coupled to a lower portion of a cylinder block 3 of a diesel engine (hereinafter simply referred to as an engine) 2 which is an internal combustion engine of a vehicle (not shown).
The cylinder block 3 protrudes outward from the cylinder block 3 over the entire area of the lower peripheral edge thereof, and has a mounting flange 4 projecting with a width L1 (see FIGS. 4 and 5). The mounting flange 4 is continuously formed with a downward sealing surface f along the peripheral edge longitudinal direction A (the direction perpendicular to the paper surface in FIGS. 4 and 5). Screw holes 5 (see FIG. 5) are sequentially formed at predetermined intervals on the downward sealing surface f.
[0011]
As shown in FIGS. 2 to 4, the oil pan 1 includes an oil pan body 7 (see FIG. 3) and an inner member 8 (see FIG. 2) laid inside the oil pan body 7. A heavy oil pan 1 is formed.
The oil pan body 7 includes a connecting flange 9 that is superimposed on the sealing surface f of the mounting flange 4 of the cylinder block 3 and a deep dish that is bent from the inner end of the oil pan of the connecting flange 9 and extends downward to form an oil pan inner chamber. The part 11 and the drain part 12 formed in the inclined wall of the deep dish part 11 are provided, and these are integrally resin-molded. The oil pan body 7 is molded from SMC, which is a composite resin material that is excellent in strength, rigidity, and heat resistance.
[0012]
SMC refers to a composite material in which an unsaturated polyester resin or vinyl ester resin is used as a base material, and chopped fibers (length 12, 5 mm) and fillers (calcium carbonate, etc.) are mixed in it. Created by molding.
As shown in FIG. 5, the connecting flange 9 of the resin-molded oil pan main body 7 is formed to extend outward from the oil pan with a protruding width L <b> 1 equivalent to the seal surface f of the mounting flange 4 of the cylinder block 3. The connecting flange 9 is formed with an upward sealing surface f1, and bolt holes 13 through which the bolts V are inserted are sequentially formed at positions facing the respective bolt holes 5 of the downward sealing surface f. Moreover, a concave recess 6 (see FIG. 5) is formed in the upward sealing surface f1 in a bead shape continuously in the peripheral longitudinal direction A from the bolt hole 13 to the inner side of the oil pan. A string-like gasket 23 having a circular cross section is press-fitted to reinforce the sealing performance of both the sealing surfaces f and f1.
[0013]
As shown in FIG. 3, the deep pan portion 11 of the oil pan body 7 has a side wall 111 extending in an annular shape in a vertical direction, and a low wall 113 extending from the lower end of these side walls 111 via an inclined wall 112, The whole has a shape having a deep bottom part a (see FIG. 3) and a shallow bottom part b where an oil pump strainer (not shown) is provided.
A drain portion 12 protruding inward of the oil pan 1 is formed on the inclined wall 112 on the deep bottom portion a side of the oil pan body 7. As shown in FIGS. 4 and 7, the drain portion 12 has a short cylindrical shape, is formed with a drain hole 14 in the center, and a peripheral edge 151 of the opening 15 of the inner member 8 to be described later (here, An annular sealing surface F is formed which can be tightly joined to the elastic ring 32 when the elastic ring 32 is engaged. The drain hole 14 is a screw hole, and prevents oil leakage by screwing the drain plug 16 except when changing the oil.
[0014]
Further, as shown in FIG. 7, the folded peripheral edge 151 is fastened and fixed in a state in which the displacement is restricted by a nut 17 that is fitted on the drain portion 12 and screwed to the drain portion 12.
As shown in FIG. 5, the inner member 8 laid in the oil pan body 7 is sandwiched between the sealing surface f of the mounting flange 4 of the cylinder block and the sealing surface f1 of the connecting flange 9, and is formed in an annular shape. A flange portion 19 and a bag-like portion 22 extending from the pinching flange portion 19 and capable of coming into contact with substantially the entire inner wall surface of the oil pan body 7 are provided.
[0015]
The inner member 8 employs a PA (polyamide) film that is excellent in oil resistance, heat resistance, and flexibility, and has a flexibility of about 0.1 to 2 mm in thickness by vacuum forming (not shown). Molded into an oil pan shape. Instead of this, a film of PET (polyethylene terephthalate) or PBT (polybutylene terephthalate) may be used.
[0016]
The pinching flange portion 19 of the inner member 8 is formed with a bolt hole 21 at a portion continuous with the bolt hole 13 of the connecting flange 9, and is an upward annular ring for locking that can be fitted to the connecting flange 9 of the cylinder block 3. A bead 23 is formed.
An opening 15 is formed at a lower portion of the bag-like portion 22 of the inner member 8 so as to be opposed to the drain portion 12. The opening 15 is closely joined to the annular seal surface F of the drain portion 12. As shown in FIG. 7, the opening 15 has an annular bulging portion 151 that bulges inward at the opening edge, and the annular bulging portion 151 is joined to the annular sealing surface F. In addition, the O-ring 17 locked in the annular groove 18 prevents the annular bulging portion 151 from shifting.
[0017]
In the oil pan 1 of FIGS. 1 and 4, when the engine is assembled, first, an inner member 8 is laid on the oil pan body 7, and at that time, the opening edge of the opening 15 is an annular sealing surface F that is a tapered surface of the drain portion 12. The annular bulging portion 151 is tightly joined to the annular sealing surface F. Next, the O-ring 17 is engaged with the annular groove 18 to prevent the opening 15 from being displaced at the annular seal surface F, and the annular bulge 151 is pressed against the side wall 111 on the side surface of the O-ring 17 to form an annular shape. Seal surfaces s (see FIG. 7) are formed at two locations on the seal surface F side and the side wall 111 side, so that oil can be prevented from entering between the oil pan body 7 and the inner member 8, and the oil pan body 7 Thus, it is possible to eliminate the trouble of removing the oil that has entered between the inner members 8 and to improve workability in this respect. Moreover, it is possible to prevent the inner member 8 from shifting within the oil pan body 7.
[0018]
Next, the gasket 23 is press-fitted into the biting recess 6 of the connecting flange 9 of the oil pan 1, and the oil pan 1 having a double structure by securely laying the inner member 8 in the oil pan body 7 is connected to the cylinder block 3. Opposite the bottom. Next, the mounting flange 4 and the connecting flange 9 are tightened with bolts V with the pinching flange portion 19 being sandwiched, and at that time, the flexible synthetic resin pressing flange portion 19 and the gasket 23 are connected to the mounting flange 4. The gap between the flanges 9 can be reliably sealed, and the installation of the oil pan 1 can be completed.
[0019]
Such an oil pan 1 has a double structure. However, since the oil pan body 7 has a structure in which only the inner member 8 is laid, the overall shape does not increase, and there is a problem in securing the installation space. It never happens. In addition, since the increase in size of the outer shape is suppressed, the ground height does not decrease, and the frequency of jumping and climbing the curb does not increase during traveling. In particular, even if the oil pan main body 7 causes chipping due to hopping or cracking damage due to curb climbing, the flexible inner member 8 is flexed and displaced alone, thus avoiding cracking and damage, Oil leakage can be prevented, and serious failures such as seizure of the engine 2 can be prevented.
[0020]
As described above, the engagement flange 9 of the oil pan 1 is formed with the biting recess 6, and the gasket 23 is press-fitted there, and the gasket 23 and the clamping flange portion 19 ensure the sealing performance. However, in some cases, as shown in FIG. 6, a biting recess portion 25 is formed in the pinching flange portion 19, and a seal portion 23 b that fits into the biting recess portion 25 protrudes from the lower surface of the pinching flange portion 19. As such, it may be integrally formed. Also in this case, the same effect as the oil pan 1 having the inner member 8 shown in FIGS. 1 and 4 can be obtained, and in particular, the apparatus can be simplified.
[0021]
In the above description, the nut 17 is screwed onto the drain portion 12 to prevent the inner member 8 from being displaced. Instead, as shown in FIG. 8A, the annular groove 18a of the drain portion 12 is provided. And the cylindrical opening 15a of the inner member 8 is fitted to the annular groove 18a covered with the cylindrical opening 15a, and the annular spring 26 is externally fitted in a pressed state to form a seal surface s. The oil may be prevented from entering between the bread body 7 and the inner member 8, and the displacement of the cylindrical opening 15 a of the inner member 8 may be prevented. Alternatively, as shown in FIG. 8B, for simplification of the apparatus, the opening 15b of the inner member 8 is adhered to the annular seal surface F of the drain portion 12 with an adhesive (not shown) (indicated by reference sign d). Oil may be prevented from entering between the oil pan main body 7 and the inner member 8 to prevent the opening 15b from being displaced. In these cases, the same effects as those of the oil pan 1 having the inner member 8 shown in FIGS.
[0022]
The inner member 8 described above is only laid in the oil pan main body 7. However, depending on the case, as shown in FIG. Boss portion 28 having a locking groove 27 is formed on the portion), and the boss portion facing portion of the inner member 8 is pushed into the locking groove 27 via a gasket 30, and a fixing plate 29 is overlapped on that portion and fixed with a screw 31. Also good. In this case, excessive displacement of the inner member 8 with respect to the inner wall of the oil pan body 7 can be prevented.
In the above description, the oil pan body 7 has been described as being made of resin. However, the present invention is not limited to this, and an oil pan body made of aluminum alloy or steel can be used. Also, the same effect as the oil pan 1 of FIG. 1 can be obtained.
[0023]
【The invention's effect】
As described above, since the invention according to claim 1 has the bag-like portion laid to be able to bend and displace independently on the entire inner wall surface of the oil pan, the oil pan is provided from the outside. Even if a crack or breakage occurs due to an impact, the flexible inner member flexes and displaces independently, and cracks and breakage are avoided. Serious failures such as engine burn-in can be prevented.
[0024]
In particular, since the periphery of the opening of the inner member to the annular sealing surface of the drain region in the second aspect of the present invention can be bonded tightly to prevent the penetration into the gap between the oil pan and the inner member of the oil, at the time of oil change Workability can be improved.
[Brief description of the drawings]
FIG. 1 is a perspective view of an oil pan engine according to an embodiment of the present invention.
FIG. 2 is a perspective view of an inner member that forms part of the oil pan of FIG. 1;
FIG. 3 is a perspective view of an oil pan main body forming a part of the oil pan of FIG. 1;
FIG. 4 is a longitudinal sectional view of an oil pan as an embodiment of the present invention.
FIG. 5 is an enlarged cutaway cross-sectional view of a portion where the oil pan of FIG. 1 is connected to a cylinder block.
6 is an enlarged cutaway cross-sectional view showing a modified example of a connecting portion of the oil pan shown in FIG. 1 connected to a cylinder block.
7 is an enlarged cutaway cross section of a drain portion of the oil pan of FIG. 1. FIG.
8 is a modified example of the drain part of the oil pan of FIG. 1, wherein (a) is an enlarged cutaway cross section showing a first modified example and (b) a second modified example.
FIG. 9 is an enlarged cutaway cross section of a joint portion between an inner member and an oil pan body that is employed in a modification of the oil pan of FIG. 1;
[Explanation of symbols]
1 Oil pan 2 Engine (internal combustion engine)
3 Cylinder block 4 Mounting flange 8 Inner member 9 Connecting flange 12 Drain portion 14 Drain hole 15 Opening portion 15a Cylindrical opening portion 17 Nut (locking member for seal)
18, 18a annular groove 19 pinching flange portion 22 bag-like portion 26 annular spring (sealing locking member)
s Seal surface F Annular seal surface V Bolt

Claims (2)

A connecting flange that is overlapped with a mounting flange at the lower peripheral edge of the cylinder block of the internal combustion engine and bolted from below, a deep dish portion that is bent and extended from the inner end of the oil pan of the connecting flange, and a drain hole that protrudes inwardly In the structure of the oil pan having a drain part formed with
An oil pan inner wall surface is formed by a clamping flange portion that is clamped between the mounting flange and the coupling flange and is formed in an annular shape, and an opening that extends from the clamping pressure flange portion and that opposes the drain portion. A structure of an oil pan comprising a flexible inner member having a bag-like portion laid so as to be able to bend and displace independently in the entire region. 2. The structure of an oil pan according to claim 1, wherein an annular sealing surface is formed on the outer peripheral edge of the drain portion so as to be closely joined to the peripheral edge of the opening of the inner member.

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