EP2093395A1

EP2093395A1 - Oil pan structure for engine

Info

Publication number: EP2093395A1
Application number: EP07829706A
Authority: EP
Inventors: Yoshiaki Koyama; Yasuhiro Hisano
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2006-12-15
Filing date: 2007-10-12
Publication date: 2009-08-26
Anticipated expiration: 2027-10-12
Also published as: WO2008072416A1; EP2093395B8; JP2008150974A; JP4625442B2; EP2093395A4; EP2093395B1

Abstract

An oil pan structure for an engine is provided in which, since a plurality of first concave-convex portions (26a) and a plurality of second concave-convex portions (27a) each extending in parallel to each other are formed on a shallow base part (22) and a deep base part (23) respectively of a base face of an oil pan (15), the plane stiffness of the oil pan (15) is enhanced, and the occurrence of resonance can be suppressed, thus reducing noise. Moreover, since an imaginary line (α) linking equal heights of the first concave-convex portions (26a) on the shallow base part (22) extends toward the deep base part (23), engine oil and impurities in the shallow base part (22) can be guided to the deep base part (23) and since, among the long side and the short side of the rectangular deep base part (23), an imaginary line (β) linking equal heights of the second concave-convex portions (27a) extends in a direction parallel to the short side, the length of the second concave-convex portions (27a) can be minimized, thereby enabling it to be made difficult for engine oil and impurities to accumulate therein and enabling them to be reliably discharged into a drain hole (28) in the base part of the oil pan (15).

Description

TECHNICAL FIELD

The present invention relates to an oil pan structure for an engine in which a base face of an oil pan that is provided in a lower part of an engine cylinder block and stores engine oil includes a shallow base part and a deep base part, a plurality of first concave-convex portions extending in parallel to each other are formed on the shallow base part, and a plurality of second concave-convex portions extending in parallel to each other are formed on the deep base part.

BACKGROUND ART

Since an oil pan provided in a lower part of an engine is a member formed by shaping a thin metal plate into a container shape, when vibration of an engine main body is transmitted thereto, a flat portion of the oil pan resonates, and there is the problem that this causes noise. In the arrangement disclosed in Patent Publication 1 below, by forming a corrugated concave-convex part on a wall face of the oil pan to thus enhance stiffness, resonance of the wall face is suppressed, thereby reducing the noise.

[Patent Publication 1] Japanese Utility Model Registration Application Laid-open No. 57-92854

DISCLOSURE OF INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

In the above-mentioned conventional oil pan, since the concave-convex part is formed in an annular shape so as to encircle the side walls of the oil pan, it is necessary for engine oil flowing down from an engine main body to traverse the concave-convex part; there is thus a possibility that it will become difficult for the engine oil to return to the base part of the oil pan, and impurities contained in the engine oil will become trapped in the concave-convex part and be difficult to be discharged.
The present invention has been accomplished in the light of the above-mentioned circumstances, and it is an object thereof to smoothly guide engine oil or impurities contained in the engine oil to a base part of an oil pan while suppressing resonance of a wall face of the oil pan.

MEANS FOR SOLVING THE PROBLEMS

In order to attain the above object, according to a first aspect of the present invention, there is provided an oil pan structure for an engine in which a base face of an oil pan that is provided in a lower part of a cylinder block of an engine and stores engine oil comprises a shallow base part and a deep base part, a plurality of first concave-convex portions extending in parallel to each other are formed on the shallow base part, and a plurality of second concave-convex portions extending in parallel to each other are formed on the deep base part, wherein an imaginary line linking equal heights of the first concave-convex portions extends toward the deep base part, the deep base part having a rectangular shape with long sides and short sides, and an imaginary line linking equal heights of the second concave-convex portions extends in a direction parallel to the short side.
Further, according to a second aspect of the present invention, in addition to the first aspect, a drain hole is formed on the long side of the deep base part.
Moreover, according to a third aspect of the present invention, in addition to the second aspect, a flat part extending from the drain hole toward the shallow base part is formed on the deep base part, and the second concave-convex portions stop at the flat part.
Furthermore, according to a fourth aspect of the present invention, in addition to the second or third aspect, an inclined face is formed in an end part, close to the drain hole, of a connecting wall connecting the shallow base part and the deep base part, the inclined face projecting into the interior of the oil pan and being inclined from the shallow base part toward the deep base part.

EFFECTS OF THE INVENTION

In accordance with the first aspect of the present invention, since the plurality of first concave-convex portions and the plurality of second concave-convex portions each extending in parallel to each other are formed on the shallow base part and the deep base part respectively of the base face of the oil pan, noise can be reduced by enhancing the plane stiffness of the oil pan and suppressing resonance. Moreover, since the imaginary line linking equal heights of the first concave-convex portions of the shallow base part extends toward the deep base part, engine oil and impurities in the shallow base part can be guided to the deep base part and since, among the long side and the short side of the rectangular deep base part, the imaginary line linking equal heights of the second concave-convex portions extends in a direction parallel to the short side, the length of the second concave-convex portions can be minimized, and this enables it to be made difficult for engine oil and impurities to accumulate therein.
Furthermore, in accordance with the second aspect of the present invention, since the drain hole is formed on the long side of the deep base part of the oil pan, compared with a case in which a drain hole is formed in a central part of a deep base part, not only is the draining operation easy, but also engine oil and impurities can be guided smoothly toward the drain hole by means of the second concave-convex portions, which extend in a direction parallel to the short side of the deep base part.
Moreover, in accordance with the third aspect of the present invention, since the flat part at which the second concave-convex portions stop is formed in the deep base part so as to extend from the drain hole toward the shallow base part, engine oil and impurities that have flowed along the second concave-convex portion can be guided effectively to the drain hole and discharged.
Furthermore, in accordance with the fourth aspect of the present invention, since the inclined face, which is inclined from the shallow base part toward the deep base part so as to project into the interior of the oil pan, is formed on an end part, close to the drain hole, of the connecting wall connecting the shallow base part and the deep base part of the oil pan, engine oil and impurities can be guided effectively from the shallow base part to the drain hole by means of the inclined face and the deep base part and discharged.

BRIEF DESCRIPTION OF DRAWINGS

[FIG. 1] FIG. 1 is a front view of an automobile engine. (first embodiment)
[FIG. 2] FIG. 2 is a view from arrow 2 in FIG. 1. (first embodiment)
[FIG. 3] FIG. 3 is a perspective view of an oil pan viewed obliquely from above. (first embodiment)
[FIG. 4] FIG. 4 is a sectional view along line 4-4 in FIG. 2. (first embodiment)
[FIG. 5] FIG. 5 is a sectional view along line 5-5 in FIG. 2. (first embodiment)
[FIG. 6] FIG. 6 is a sectional view along line 6-6 in FIG. 2. (first embodiment)
[FIG. 7] FIG. 7 is a sectional view along line 7-7 in FIG. 2. (first embodiment)

EXPLANATION OF REFERENCE NUMERALS AND SYMBOLS

11: Cylinder block
15: Oil pan
22: Shallow base part
23: Deep base part
24: Connecting wall
26a to 26d: First concave-convex portions
27a to 27g: Second concave-convex portions
28: Drain hole
30: Flat part
38: Inclined face
E: Engine
α,: Imaginary line on first concave-convex portion
β: Imaginary line on second concave-convex portion

BEST MODE FOR CARRYING OUT THE INVENTION

A mode for carrying out the present invention is explained below by reference to the attached drawings.

EMBODIMENT 1

FIG. 1 to FIG. 7 show a mode for carrying out the present invention.
As shown in FIG. 1, joined to an upper part of a cylinder block 11 of an automobile engine E are a cylinder head 12 and a head cover 13, joined to a lower part of the cylinder block are a lower block 14 and an oil pan 15, and rotatably supported on mating faces of the cylinder block 11 and the lower block 14 is a crankshaft 16. The engine E is mounted on a vehicle body in an attitude in which its upper part is inclined toward the rear of the vehicle body. Mating faces of a lower face of the lower block 14 and an upper face of the oil pan 15 are therefore inclined so that the side toward the front of the vehicle body is higher. Since the base face of the oil pan 15, in which engine oil is stored, is substantially horizontal, the height of the front part of the oil pan 15 is greater than the height of the rear part thereof.
As is clear from FIG. 2 and FIG. 3, a flange 18 is formed on the periphery of the oil pan 15, the flange 18 being joined to the lower face of the lower block 14 of the engine E via a plurality of bolts 17. Furthermore, a parting face 19 formed on one end part of the oil pan 15 is joined to a lower part of a transmission 21 (see FIG. 2) via two bolts 20 and 20. The oil pan 15 includes a shallow base part 22 connected to the transmission 21 and a deep base part 23 connected to the shallow base part 22 on the opposite side to the transmission 21, the shallow base part 22 and the deep base part 23 are connected via a connecting wall 24, and an exhaust pipe 25 runs through a space beneath the shallow base part 22, the exhaust pipe 25 (see FIG. 1) extending downward from the cylinder head 12 and bending rearward.
Formed on the shallow base part 22 of the oil pan 15 are four ridge-shaped beads protruding toward the interior of the oil pan 15. The beads form first concave-convex portions 26a to 26d of the present invention, and an imaginary line α (see FIG. 3) linking equal heights thereof extends in the direction in which the transmission 21 and the deep base part 23 are joined (direction of the crankshaft 16).
Furthermore, the deep base part 23 of the oil pan 15 is formed in a substantially rectangular shape with long sides along the direction of the crankshaft 16 and short sides extending in a direction perpendicular thereto, one of the short sides being connected to the shallow base part 22 via the connecting wall 24. Formed on the deep base part 23 are seven ridge-shaped beads protruding toward the interior of the oil pan 15. The beads form second concave-convex portions 27a to 27g of the present invention, and an imaginary line β (see FIG. 3) linking equal heights thereof extends in a direction along the short side, that is, a direction perpendicular to the first concave-convex portions 26a to 26d.
Among the seven second concave-convex portions 27a to 27g, the three portions 27a to 27c that are on the side close to the shallow base part 22 are relatively long, the four portions 27d to 27g that are on the side distant from the shallow base part 22 are relatively short, and among the four short portions 27d to 27g, one portion 27g and another portion 27d are aligned on one straight line.
As is clear from FIG. 2 to FIG. 4, among the two long sides of the deep base part 23 of the oil pan 15, a drain hole 28 is formed on the rear long side, and this drain hole 28 is opened and closed by a detachable drain bolt 29. A flat part 30 (see hatched parts in FIG. 2 and FIG. 3) is formed on a base face of the deep base part 23, the second concave-convex portions 27a to 27g not being present on the flat part 30 from the periphery of the drain hole 28 toward the connecting wall 24.
As is clear from FIG. 2, FIG. 3, and FIG. 7, a circular oil level sensor mounting part 31 protrudes toward the interior of the oil pan 15 from the base face of the deep base part 23, of which two sides being surrounded by the second concave-convex portions 27d to 27g, and an oil level sensor mounting hole 32 opens in a central part of the oil level sensor mounting part 31. A harness-housing recess 33 is formed in a groove shape from the oil level sensor mounting part 31 toward a corner on the opposite side to the transmission 21.
An oil level sensor 34 includes a disk-shaped mounting portion 34a, a detection portion 34b projecting from the mounting portion 34a toward the interior of the oil pan 15, and a harness 34c extending from the mounting portion 34a. The mounting portion 34a is fixed to the oil level sensor mounting part 31 via three bolts 35 in a state in which the detection portion 34b is inserted into the oil pan 15 from the oil level sensor mounting hole 32, and a cover 36 covering the oil level sensor mounting part 32 and the harness-housing recess 33 is fixed to the oil pan 15 via four bolts 37 in a state in which the harness 34c is housed in the harness-housing recess 33.
As is clear from FIG. 2, FIG. 3, and FIG. 6, an inclined face 38 is formed from the connecting wall 24 to the flat part 30 of the deep base part 23, the inclined face 38 projecting toward the interior of the oil pan 15. A tool channel 39 is formed in a lower face of the oil pan corresponding to the inclined face 38, and inserting a wrench 40 by utilizing this tool channel 39 enables one of the two bolts 20 and 20 securing the oil pan 15 to the transmission 21 to be efficiently tightened.
As hereinbefore described, since the oil pan 15 includes the plurality of first concave-convex portions 26a to 26d on the shallow base part 22 and the plurality of second concave-convex portions 27a to 27g on the deep base part 23, the plane stiffness thereof is enhanced, and the occurrence of resonance due to vibration of the engine E can be prevented, thus contributing to a reduction in noise.
Engine oil that has lubricated a valve operating mechanism, sliding parts of a piston and a cylinder, a journal of the crankshaft 16, etc. is returned to the base part of the oil pan 15 by virtue of gravity, and when the engine oil is drained via the drain hole 28 by removing the drain bolt 29 for engine oil change, since engine oil that has collected in the shallow base part 22, which is at a high position, flows smoothly along the first concave-convex portions 26a to 26d, and flows from the end thereof into the deep base part 23, which is at a low position, along the connecting wall 24, engine oil or impurities, etc. contained therein do not accumulate by being trapped in the valleys of the concave-convex portions of the shallow base part 22 (see FIG. 5).
Furthermore, since the drain hole 28 is provided so as to point in the horizontal direction on the long side of the rectangular deep base part 23 on the side toward the rear of the vehicle body, compared with a case in which it is provided so as to point in the vertical direction in a central part of the deep base part 23, attachment and detachment of the drain bolt 29 is easy. Since the engine oil in the deep base part 23 flows toward the drain hole 28 side along the second concave-convex portions 27a to 27g along the direction of the short side, engine oil or impurities, etc. contained therein do not accumulate by being trapped in the valleys of the concave-convex portions of the deep base part 23. Since these second concave-convex portions 27a to 27g are disposed in parallel to the short side of the rectangular deep base part 23, the length of the second concave-convex portions 27a to 27g can be minimized, and this enables it to be made as difficult as possible for engine oil, impurities, etc. to accumulate.
In this arrangement, since the flat part 30, at which the second concave-convex portions 27a to 27g stop, is formed on the base face of the deep base part 23 in the vicinity of the drain hole 28, engine oil and impurities that have flowed along the second concave-convex portions 27a to 27g collect in the flat part 30 and are then discharged smoothly through the drain hole 28. Furthermore, since the inclined face 38 connected to the flat part 30 of the deep base part 23 is formed on the connecting wall 24 connecting the shallow base part 22 and the deep base part 23, engine oil and impurities in the shallow base part 22 are guided by the inclined face 38 more smoothly to the flat part 30. In particular, since this inclined face 38 is formed by utilizing the tool channel 39 for the wrench 40 to be inserted through, it is unnecessary to employ special machining, thus reducing the number of machining steps.
An embodiment of the present invention is explained above, but the present invention may be modified in a variety of ways as long as the modifications do not depart from the spirit and scope thereof.
For example, the deep base part 23 of the oil pan 15 has its long side coinciding with the direction along the crankshaft 16, but its short side may coincide with the direction along the crankshaft 16. In this case, the direction of the first concave-convex portions 26a to 26d is parallel to the direction of the second concave-convex portions 27a to 27g, and discharge of engine oil or impurities can be carried out more smoothly.

Claims

An oil pan structure for an engine in which a base face of an oil pan (15) that is provided in a lower part of a cylinder block (11) of an engine (E) and stores engine oil comprises a shallow base part (22) and a deep base part (23), a plurality of first concave-convex portions (26a to 26d) extending in parallel to each other are formed on the shallow base part (22), and a plurality of second concave-convex portions (27a to 27g) extending in parallel to each other are formed on the deep base part (23),
wherein an imaginary line (α) linking equal heights of the first concave-convex portions (26a to 26d) extends toward the deep base part (23), the deep base part (23) having a rectangular shape with long sides and short sides, and an imaginary line (β) linking equal heights of the second concave-convex portions (27a to 27g) extends in a direction parallel to the short side.
The oil pan structure for the engine according to Claim 1, wherein a drain hole (28) is formed on the long side of the deep base part (23).
The oil pan structure for the engine according to Claim 2, wherein a flat part (30) extending from the drain hole (28) toward the shallow base part (22) is formed on the deep base part (23), and the second concave-convex portions (27a to 27g) stop at the flat part (30).
The oil pan structure for the engine according to Claim 2 or Claim 3, wherein an inclined face (38) is formed in an end part, close to the drain hole (28), of a connecting wall (24) connecting the shallow base part (22) and the deep base part (23), the inclined face (38) projecting into the interior of the oil pan (15) and being inclined from the shallow base part (22) toward the deep base part (23).