JP2827835B2 - Oil pan vibration control structure of internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an oil pan vibration control structure of an internal combustion engine.

[0002]

2. Description of the Related Art In an internal combustion engine for a vehicle, an oil pan for storing lubricating oil is provided at a lower portion of a cylinder block, and lubricating oil is sucked up by an oil pump and supplied to various parts of the engine. Since this oil pan has a thin-walled structure generally formed by pressing a metal plate,
The vibrating force from the engine body may cause membrane vibration to generate noise.

For this reason, conventionally, for example, Japanese Utility Model Laid-Open No.
As disclosed in Japanese Patent No. 5941, an oil pan has a double structure of an outer plate and an inner plate, and lubricating oil is introduced into a gap between the two through a number of small holes provided in the inner plate. A vibration damping structure has been proposed. This is because the lubricating oil flows into and out of the gap through the small hole of the inner plate with the film vibration of the oil pan, and the film vibration is suppressed by the loss at that time.

However, in such a conventional structure, since the inner plate having a large number of small holes is fixed inside the outer plate with a small gap, the structure becomes complicated and the machining accuracy is required. Cost increases.

[0005] The thinner the oil film layer, that is, the smaller the gap between the outer plate and the inner plate, the greater the effect of damping the vibration energy associated with the flow of the lubricating oil. With a fixed structure, there is a limit in making the gap thinner, and a sufficient damping effect cannot be obtained.

As a countermeasure against this, the present applicant has filed Japanese Patent Application No.
No. 161144, an oil pan vibration damping structure for an internal combustion engine shown in FIGS. 8 and 9 has already been proposed.

To explain this, the inner pan 3 having a wall surface along the inner wall surface of the oil pan 1 is not fixed to the oil pan 1, but is sunk in the lubricating oil of the oil pan 1 by its own weight. An oil film layer 4 is formed between the wall surface of the oil pan 3 and the inner wall surface of the oil pan 1. When the oil pan 1 causes film vibration, the lubricating oil tends to flow along the wall surface in the thin oil film layer with the minute change in the distance between the oil pan 1 and the inner pan 3, thereby damping the vibration energy. The effect to be obtained is obtained.

A stopper 4 having an L-shaped cross section is fixed to a side wall of the oil pan 1, and an inner pan 3 is interposed below the stopper 4. When the inner pan 3 abuts on the stopper 4, the movable range of the inner pan 3 with respect to the oil pan 1 is regulated.

A reinforcing member 2 is fixed to the oil pan 1. Even when the rigidity of the oil pan 1 is increased by the reinforcing member 2, it is possible to suppress the occurrence of film vibration due to the excitation force from the engine.

[0010]

However, in such a conventional oil pan vibration damping structure for an internal combustion engine,
Since the inner pan 3 covers the reinforcing member 2 and faces the oil pan 1, the area of the inner pan 3 facing the oil pan 1 is reduced to avoid the reinforcing member 2, and the vibration damping effect of the oil film layer 4 is impaired. There is a problem that it is done.

Further, it is necessary to mount a plurality of stoppers 4 for restricting the movable range of the inner pan 3 on the oil pan 1, which may increase the number of parts and deteriorate productivity.

An object of the present invention is to improve the vibration damping effect without complicating the structure of an oil pan, focusing on the above problems.

[0013]

According to the first aspect of the present invention,
An inner pan having an oil pan mounted on the main body of the internal combustion engine and storing lubricating oil and having a wall shape along the inner wall surface of the oil pan including at least a part of the bottom surface of the oil pan is not fixed to the oil pan. In the oil pan damping structure of the internal combustion engine, which sinks into the lubricating oil of the oil pan by its own weight and forms an oil film layer between the inner pan wall and the inner wall of the oil pan, it is fixed to the inner wall of the oil pan The inner pan is interposed between the reinforcing member and the oil pan, and the reinforcing member has a portion that regulates a movable range of the inner pan with respect to the oil pan.

According to a second aspect of the present invention, in the oil pan vibration damping structure for an internal combustion engine according to the first aspect of the present invention, the inner pan is joined to the reinforcing member so as to extend from a portion for regulating the movable range to the inner wall surface of the oil pan. A projection that projects in a substantially truncated cone shape is formed, and the tip of the projection is fixed to the inner wall surface of the oil pan, while an engagement hole that allows the projection to pass through the inner pan is formed.

According to a third aspect of the present invention, in the oil pan vibration damping structure for an internal combustion engine according to the first aspect of the present invention, the reinforcing member has a planar shape in which a portion for regulating the movable range of the inner pan is substantially parallel to the inner pan. Formed.

[0016]

In the oil pan vibration damping structure for an internal combustion engine according to the first aspect, the inner pan sinks into the lubricating oil by its own weight, whereby the inner wall surface of the oil pan and the inner pan wall come close to each other via a thin oil film layer. In this state, when the oil pan receives a vibrating force from the engine main body and causes film vibration, the distance between the oil pan and the inner pan changes minutely, and accordingly, the lubricating oil of the oil film layer flows along the two surfaces. To flow, and a damping action of vibration energy is obtained.

When the inner pan is largely separated from the oil pan by an external impact or the like, the movement of the inner pan is restricted by the reinforcing member, and the inner pan is prevented from interfering with a crankshaft, a connecting rod and the like provided above the inner pan. .

[0018]

Since the inner pan is interposed between the reinforcing member and the oil pan, the reduction of the area of the inner pan facing the oil pan in order to avoid the reinforcing member is minimized, and the vibration of the oil pan by the oil film layer is reduced. The suppression effect can be increased.

In addition, since the reinforcing member that reinforces the oil pan has a function of restricting the movable range of the inner pan, the number of components attached to the oil pan by the member that restricts the movable range of the inner pan increases. Can be avoided.

In the oil pan vibration damping structure for an internal combustion engine according to the second aspect, the convex portion protrudes from the reinforcing member into a truncated cone shape, so that the inner pan near the bottom surface of the oil pan does not hit the convex portion, and the oil film is formed. The oil pan vibration suppression effect of the layer is not impaired.

According to the third aspect of the present invention, when the movement of the inner pan is restricted by the reinforcing member, the inner pan is substantially parallel to the reinforcing member and is therefore sandwiched between the two. The impact of the inner pan colliding with the reinforcing member is reduced by the squeeze effect of the lubricating oil film.

[0023]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1, the oil pan 1 is formed by press-forming a steel plate. A portion near the front end of the engine (not shown) has a substantially rectangular deep bottom portion 11 and a portion near the rear end of the engine has a substantially rectangular shallow portion. It is the bottom 12. Lubricating oil that has lubricated each part of the engine is collected in the deep bottom part 11 through the shallow bottom part 12, and the lubricating oil stored in the deep bottom part 11 is sucked up by an oil pump and supplied to each part of the engine.

A joining flange 13 for a cylinder block (not shown) is formed on the outer peripheral edge of the oil pan 1. The joining flange 13 is fastened to the cylinder block via a plurality of bolts.

As shown in FIGS. 2 and 3, the oil pan 1
, Three reinforcing members 2 are fixed. Each reinforcing member 2 is formed in a U-shape, and the side wall surface 14 and the bottom surface 1 of the oil pan 1 are formed.
5 is fixed. By increasing the rigidity of the oil pan 1 by the reinforcing member 2, it is possible to suppress the occurrence of membrane vibration due to the excitation force from the engine.

Inside the oil pan 1, an inner pan 3 formed by press-forming a steel plate is housed. Like the oil pan 1, the inner pan 3 has a substantially rectangular deep bottom 3 and a shallow bottom 32.
And has a shape along the inner wall surface of the oil pan 1 as a whole.

That is, when the inner pan 3 is fitted in the oil pan 1, the inner pan 3 is substantially similar in shape to the oil pan 1 so that a slight gap can be formed between the wall surfaces. It is formed to have dimensions slightly smaller than the wall surface.

The inner pan 3 has its own weight and the oil pan 1
It sinks in the lubricating oil inside and is not fixed to the oil pan 1. That is, the inner pan 3 is the oil pan 1
Is naturally sunk, and an oil film layer 4 is formed between the inner wall surface of the oil pan 1 and the wall surface of the inner pan 3.

The reinforcing member 2 has the inner pan 3 interposed between the reinforcing member 2 and the oil pan 1 and regulates the movable range of the inner pan 3 with respect to the oil pan 1.

In this embodiment, as a movable range restricting portion of the inner pan 3, each reinforcing member 2 has an oil pan bottom surface 15 and a substrate portion 21 which is opposed to the inner pan 3 in parallel with a predetermined gap. A convex portion 2 projecting from each substrate portion 21 toward the bottom surface 15 of the oil pan 1 in a substantially truncated cone shape.
2 is formed by press molding.

As shown in FIG. 4, the convex portion 22 has a conical portion 23 whose diameter gradually decreases toward the oil pan bottom surface 15, and a disk-shaped tip portion 24 joined to the oil pan bottom surface 15.

Each of the reinforcing members 2 is formed with five convex portions 22 at regular intervals, and the tip portions 23 of the convex portions 22 are fixed to the oil pan 1 by spot welding.

An engagement hole 33 for inserting each projection 22 into the inner pan 3 is formed in a circular shape. The engagement hole 33 is the conical portion 23
Are formed at a predetermined ratio larger than the maximum diameter, and a gap is provided between them.

At both ends of each reinforcing member 2, a pair of convex portions 25 which are joined to and fixed to the oil pan side wall surface 14 are formed.

A notch 34 is formed to allow each projection 25 to pass through the inner pan 3. The notch 34 is formed with a predetermined gap with respect to the protrusion 25, and does not restrict the movable range of the inner pan 3 with respect to the oil pan 1 by the protrusion 25.

The operation will be described next.

When the bottom surface 15 and the side wall surface 14 of the oil pan 1 undergo film vibration due to the excitation force from the cylinder block side, the distance between the oil pan 1 and the inner pan 3 is slightly changed, and the oil film is accordingly changed. The lubricating oil of layer 4 tends to flow along two surfaces. Therefore, the vibration energy is converted into the kinetic energy of the lubricating oil, and is attenuated by friction with each wall surface or friction between the lubricating oils. Therefore, the vibration that actually occurs is greatly suppressed, and the radiation sound generated from the oil pan 1 is reduced. In particular, with respect to the oil film layer 4 between the oil pan bottom surface 15 and the inner pan 3, the own weight of the inner pan 3 acts, so that the oil pressure increases, and the lubricating oil flows under the high pressure. Can be obtained even larger. This damping effect is effective in a wide frequency range like the vibration element in the general vibration model, and the radiation sound generated from the oil pan 1 can be reduced as a whole. Even when the entire engine vibrates greatly, the inner pan 3 is restrained by the viscosity of the lubricating oil in the oil film layer 4 and does not collide with the oil pan 1.

The impact transmitted from the vehicle body and the oil pan 1
When the inner pan 3 tends to be largely separated from the oil pan 1 when the
The movement of the inner pan 3 is regulated by the substrate 21 of the reinforcing member 2. For this reason, it is possible to prevent the inner pan 3 from interfering with a not-shown crankshaft, connecting rod, or the like provided thereabove.

As described above, when the movement of the inner pan 3 due to an externally applied impact is restricted by the reinforcing member 2, the inner pan 3 tends to be surface-bonded to the substrate portion 21, so that the squeezing effect of the lubricating oil film sandwiched between the two. Accordingly, the impact of the inner pan 3 colliding with the reinforcing member 2 is reduced.

Since the convex portion 22 protrudes from the reinforcing member 2 in the shape of a truncated cone, the inner pan 3 near the oil pan bottom surface 15 is prevented from hitting the convex portion 22, and the oil film layer 4 suppresses vibration of the oil pan 1. The effect is not lost.

The inner pan 3 is connected to the reinforcing member 2 and the oil pan 1
Since the space between the inner pan 3 and the oil pan 1 is reduced to avoid the reinforcing member 2, the effect of suppressing the vibration of the oil pan 1 by the oil film layer 4 can be enhanced. . FIG. 5 is a characteristic diagram showing a radiation sound of the oil pan 1 in the configuration of this embodiment in comparison with a conventional one without the inner pan 3.

Further, in the above configuration, since the reinforcing member 2 which functions to reinforce the oil pan 1 also has a function of restricting the movable range of the inner pan 3, the oil pan 1 is restricted by the member which restricts the movable range of the inner pan 3. It is possible to avoid an increase in the number of parts attached to the vehicle.

Next, another embodiment shown in FIGS. 6 and 7 will be described. 1 and 2 are designated by the same reference numerals.

Three reinforcing members 2 are fixed to the oil pan 1. Each reinforcing member 2 is formed in a frame shape extending linearly, and is fixed to the bottom surface 15 of the oil pan 1. By increasing the rigidity of the oil pan 1 by the reinforcing member 2, it is possible to suppress the occurrence of membrane vibration due to the excitation force from the engine.

In this embodiment, as the movable range restricting portion of the inner pan 3, each reinforcing member 2 is a flat plate-like substrate 26 which is opposed to the oil pan bottom surface 15 and the inner pan 3 in parallel with a predetermined gap. A convex portion 27 is formed by press molding, and is bent from the pair of substrate portions 26 toward the bottom surface 15 of the oil pan 1.

The convex portion 27 extends linearly with a U-shaped cross section, and the tip portion 29 of the convex portion 27 is fixed to the bottom surface 15 of the oil pan 1 by spot welding.

An engagement hole 35 through which each projection 25 is inserted into the inner pan 3 is formed in a rectangular shape. The engagement hole 35 is formed larger than the outer dimension of the projection 27 at a predetermined ratio, and a gap is provided between the two.

Also in this case, when the movement of the inner pan 3 due to an external impact is restricted by the reinforcing member 2,
Since the inner pan 3 is to be surface-bonded to the substrate 26, the impact of the inner pan 3 colliding with the reinforcing member 2 is reduced by the squeeze effect of the lubricating oil film sandwiched between the two.

[0050]

As described above, according to the first aspect of the present invention, the inner pan having the wall surface shaped along the inner wall surface of the oil pan is sunk into the lubricating oil of the oil pan by its own weight, In an oil pan damping structure for an internal combustion engine that forms an oil film layer between the oil pan layer and an inner wall surface of the oil pan, a reinforcing member fixed to the inner wall surface of the oil pan is provided,
Since the inner pan is interposed between the reinforcing member and the oil pan, and the reinforcing member has a portion that regulates the movable range of the inner pan with respect to the oil pan, the area of the inner pan facing the oil pan is reduced to avoid the reinforcing member. That is, the effect of suppressing the vibration of the oil pan by the oil film layer can be enhanced. In addition, since the inner pan has a function of restricting the movable range to the reinforcing member that functions to reinforce the oil pan, the number of components attached to the oil pan can be prevented from increasing due to the member that restricts the movable range of the inner pan. , Can increase productivity.

According to a second aspect of the present invention, in the oil pan vibration damping structure for an internal combustion engine according to the first aspect of the present invention, the inner pan is joined to the reinforcing member so as to extend from a portion for regulating the movable range to the inner wall surface of the oil pan. A convex portion protruding in a substantially truncated cone shape is formed, and the distal end portion of the convex portion is fixed to the inner wall surface of the oil pan, while an engaging hole for inserting the convex portion into the inner pan is formed, so that it is near the bottom surface of the oil pan. The inner pan is prevented from hitting the convex part, and the effect of suppressing the vibration of the oil pan by the oil film layer is not impaired.

According to a third aspect of the present invention, in the oil pan vibration damping structure for an internal combustion engine according to the first aspect of the present invention, the reinforcing member restricts the movable range of the inner pan in a planar shape substantially parallel to the inner pan. When the movement of the inner pan is regulated by the reinforcing member, the inner pan is substantially parallel to the reinforcing member, so that the inner pan collides with the reinforcing member due to the squeeze effect of the lubricating oil film sandwiched between the inner pan and the inner member. Shock is reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an oil pan and the like taken along a line CC of FIG. 2, showing an embodiment of the present invention.

FIG. 2 is a plan view of an oil pan and the like.

FIG. 3 is a sectional view of the oil pan and the like along the line DD in FIG. 2;

FIG. 4 is an enlarged sectional view of a portion E in FIG. 3;

FIG. 5 is a diagram showing characteristics of radiation sound generated from the oil pan.

FIG. 6 is a plan view of an oil pan and the like showing another embodiment.

FIG. 7 is a cross-sectional view of the oil pan and the like along the line FF in FIG. 6;

FIG. 8 is a plan view of an oil pan and the like showing a conventional example.

FIG. 9 is a sectional view of the oil pan and the like along the line BB in FIG. 8;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Oil pan 2 Reinforcement member 3 Inner pan 4 Oil film layer 15 Oil pan bottom surface 21 Substrate part 22 Convex part 23 Conical part 26 Substrate part 27 Convex part 33 Engagement hole 35 Engagement hole

Continuation of the front page (56) References JP-A-7-19107 (JP, A) JP-A 63-126507 (JP, U) JP-A 62-128148 (JP, U) JP-A 61-140235 (JP , U) Actually open 56-161156 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F16N 35/00 F02F 7/00 F01M 11/00

Claims (3)

(57) [Claims] 1. An inner pan having an oil pan mounted on a main body of an internal combustion engine and storing lubricating oil, the inner pan having at least a part of a bottom surface of the oil pan and having a wall shape formed along an inner wall surface of the oil pan. In an oil pan damping structure of an internal combustion engine in which an oil film layer is formed between an inner wall surface and an inner wall surface of an oil pan by being immersed in lubricating oil of the oil pan by its own weight without being fixed to the pan, An internal combustion engine, comprising: a reinforcing member fixed to an inner wall surface of an inner pan; an inner pan interposed between the reinforcing member and the oil pan; and the reinforcing member having a portion that regulates a movable range of the inner pan with respect to the oil pan. Oil pan damping structure. 2. An inner pan is joined to a reinforcing member to form a convex portion protruding in a substantially truncated cone shape from a portion for regulating a movable range thereof toward an inner wall surface of the oil pan, and a tip of the convex portion is formed in the oil pan. 2. An oil pan vibration damping structure for an internal combustion engine according to claim 1, wherein an engagement hole is formed to be fixed to an inner wall surface of the inner pan while allowing a projection to pass through the inner pan. 3. An oil pan vibration damping structure for an internal combustion engine according to claim 1, wherein a portion for regulating the movable range of the inner pan is formed in the reinforcing member in a planar shape substantially parallel to the inner pan. .