JP3957518B2 - Oil pan for internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an oil pan for an internal combustion engine.
[0002]
[Prior art]
An oil pan for an internal combustion engine is disclosed in Japanese Utility Model Laid-Open No. 5-4642. The oil pan is generally attached to the lower wall surface of the cylinder block of the internal combustion engine, and stores lubricating oil that is circulated through the internal combustion engine and lubricates sliding parts of the internal combustion engine. Various characteristics are required for oil pans. In the above publication, in order to improve the vibration absorption characteristics and sound absorption characteristics of the oil pan, the oil pan is composed of a multilayer board formed by sandwiching a core layer made of a metal porous body with an oil-tight layer made of a synthetic resin. ing.
[0003]
[Problems to be solved by the invention]
By the way, the lubricating oil circulates in the internal combustion engine more smoothly as its viscosity is lower. Therefore, the lower the viscosity of the lubricating oil, the higher the lubricating performance. However, since the temperature of the lubricating oil when the internal combustion engine is started is low, in order to improve the lubricating performance of the lubricating oil, it is necessary to quickly raise the temperature of the lubricating oil after the engine is started. Otherwise, the internal combustion engine will be insufficiently lubricated, the frictional resistance of the sliding parts of the internal combustion engine will be large, and as a result, the fuel consumption of the internal combustion engine will deteriorate. Therefore, an object of the present invention is to quickly increase the temperature of the lubricating oil stored in the oil pan after the engine is started.
[0004]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, in the first invention, in an oil pan of an internal combustion engine comprising a plate molded to define a storage space for storing lubricating oil, the plate has a large number of pores. It is made of a porous material , and the average porosity of the porous material is larger in the inner region than in the region near the surface of the plate. Here, the pores inside the plate serve as a heat insulating layer.
[0005]
In a second invention, in the first invention, a gel-like resin layer is disposed in the internal region having a large average porosity.
[0006]
In a third aspect, in the first aspect, a thin metal plate is disposed in the internal region having a large average porosity.
[0007]
In a fourth invention, in the first invention, the plate is composed of only one kind of porous material.
According to a fifth aspect, in the first aspect, the average porosity of the porous material gradually increases from the region near the surface toward the internal region.
According to a sixth aspect, in the first aspect, there are no pores on the plate surface.
In a seventh aspect based on the first aspect, the porous material has a region where the average porosity is a maximum in the internal region where the average porosity is large.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The oil pan of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of an internal combustion engine including an oil pan according to a first embodiment. In FIG. 1, 1 is a cylinder block, 2 is a cylinder head, 3 is an oil pan. The cylinder head 2 is mounted on the cylinder block 1. The oil pan 3 is attached to the attachment flange 5 of the cylinder block 1 via the attachment flange 4. The oil pan 3 is formed from a plate 6. The plate 6 defines a storage space 7 for storing lubricating oil for lubricating the sliding parts of the internal combustion engine.
[0009]
FIG. 2 is a longitudinal sectional view of the bottom wall of the plate 6 that defines the storage space 7 of the oil pan 3. The plate 6 is made of a porous material such as foamed resin or foamed metal. Therefore, a large number of pores 6 a exist inside the plate 6. The average porosity in the inner central region B of the plate 6 is larger than the average porosity in the region in the vicinity of the inner wall surface A of the plate 6 on the storage space 7 side, and in the region in the vicinity of the outer wall surface B of the plate 6 on the outer world side. Greater than average porosity. In particular, the average porosity of the plate 6 gradually increases from both wall surfaces to the inner central region. Of course, there are no pores on both wall surfaces of the plate 6 so that the lubricating oil does not leak from the storage space 7 through the plate 6 to the outside world. Not. In addition, as a porous material which comprises the plate 6, the material with a small heat capacity and a small heat transfer rate is preferable.
[0010]
The oil pan according to the first embodiment has the following advantages. When the internal combustion engine is started, the lubricating oil is circulated in the internal combustion engine. Thereby, lubricating oil is heated and the temperature rises. Here, the pores 6a inside the plate 6 of the oil pan 3 function as a heat insulating layer. Therefore, the pores 6a in the plate 6 suppress the heat of the lubricating oil being heated by the internal combustion engine from being radiated to the outside through the plate 6. In particular, since the average porosity of the inner central region B of the plate 6 is large, radiation of the heat of the lubricating oil to the outside is more reliably suppressed. Further, the heat of the lubricating oil is also suppressed from being radiated to the cylinder block 1 through the plate 6. Therefore, according to the present invention, the temperature of the lubricating oil is quickly raised after the internal combustion engine is started.
[0011]
Moreover, since the average porosity of the plate 6 is large, the bending rigidity of the plate 6 is high. That is, the strength of the oil pan 3 is high. Even if the outer wall surface of the plate 6 is cracked, the pores 6a inside the plate 6 serve to stop the growth of the crack, so that the entire plate 6 is prevented from cracking.
[0012]
In addition, the first embodiment has the characteristics that the heat insulating property against the lubricating oil is high and the strength thereof is high as described above, and in addition, the plate 6 is formed of only a single porous material. Therefore, there is an advantage that the oil pan 3 can be manufactured with a small number of manufacturing steps.
[0013]
In order to quickly increase the temperature of the lubricating oil after the internal combustion engine is started, at least the internal portion of the plate 6 corresponding to the region where the lubricating oil is always accumulated in the storage space 7 is as described above. The average porosity only needs to increase as going from both wall surfaces to the inner central region.
[0014]
Next, an oil pan according to a second embodiment will be described. The oil pan of the second embodiment is shown in FIG. FIG. 3 is a longitudinal section of the bottom wall of the plate of the oil pan according to the second embodiment. In the second embodiment, the average porosity of the inner central region B of the plate 6 is increased to the maximum, thereby forming the space 8. In the space 8, a gel-like soft resin layer 9 is disposed on the lower wall surface defining the space 8.
[0015]
The oil pan of the second embodiment has the following advantages in addition to the advantages described in relation to the first embodiment. That is, in the second embodiment, since the average porosity of the inner central region B of the plate 6 is maximized, the heat insulating property of the plate 6 is higher than the heat insulating property in the first embodiment. Further, when a crack is formed on the outer wall surface side of the plate 6 and this crack reaches the lower wall surface defining the space 8, the resin of the resin layer 9 flows into the crack, and the crack that has entered the plate 6 is closed by the resin. It is done. Of course, also in the second embodiment, since the growth of cracks entering from the outer wall surface side of the plate 6 is stopped by the space 8, it is possible to prevent the entire plate 6 from cracking.
[0016]
In addition, since the resin layer 9 is disposed inside the plate 6, the resin of the resin layer 9 does not come into contact with outside air or lubricating oil, and therefore, deterioration of the resin is suppressed. Thus, since deterioration is suppressed, cheap resin can also be used.
[0017]
Next, an oil pan according to a third embodiment will be described. The oil pan of the third embodiment is shown in FIG. FIG. 3 is a longitudinal sectional view of the bottom wall of the oil pan plate of the third embodiment. Also in the third embodiment, the average porosity of the inner central region B of the plate 6 is increased to the maximum, thereby forming the space 8. In the space 8, a thin plate 10 made of metal, preferably iron, is disposed on the lower wall surface that defines the space 8.
[0018]
The oil pan of the third embodiment has the following advantages in addition to the advantages described in relation to the first embodiment. That is, also in the third embodiment, as in the second embodiment, the average porosity of the inner central region B of the plate 6 is maximized, so that the heat insulation of the plate 6 is the heat insulation in the first embodiment. Higher than sex.
[0019]
Moreover, in 3rd Embodiment, since the iron thin plate 10 is arrange | positioned inside the plate 6, the intensity | strength of the plate 6 is higher than the intensity | strength in 1st Embodiment. Furthermore, in 3rd Embodiment, since the thin plate 10 is arrange | positioned inside the plate 6, the thin plate 10 does not touch external air or lubricating oil. Therefore, since deterioration due to oxidation or the like of the thin plate 10 is suppressed, it is not necessary to apply a coating for preventing the deterioration to the thin plate 10, and the manufacturing cost is reduced.
[0020]
【The invention's effect】
According to the present invention, the pores inside the plate serve as a heat insulating layer, and since the large pores exist in the inner region of the plate, the heat insulating property against the lubricating oil is high. Therefore, according to the present invention, the temperature of the lubricating oil can be quickly raised after the engine is started.
[Brief description of the drawings]
FIG. 1 is a diagram showing an internal combustion engine provided with an oil pan according to the present invention.
FIG. 2 is a longitudinal sectional view of the bottom wall of the plate of the oil pan according to the first embodiment.
FIG. 3 is a longitudinal sectional view of a bottom wall of a plate of an oil pan according to a second embodiment.
FIG. 4 is a longitudinal sectional view of a bottom wall of a plate of an oil pan according to a third embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Cylinder block 2 ... Cylinder head 3 ... Oil pan 6 ... Plate 7 ... Storage space 9 ... Resin layer 10 ... Thin plate

Claims (7)

In an oil pan of an internal combustion engine comprising a plate molded to define a storage space for storing lubricating oil, the plate is formed of a porous material having a number of pores, and the average pores of the porous material An oil pan characterized in that the rate is greater in the inner region than in the region near the surface of the plate.   The oil pan according to claim 1, wherein a gel-like resin layer is disposed in the internal region having a large average porosity.   The oil pan according to claim 1, wherein a metal thin plate is disposed in the internal region having a high average porosity.   The oil pan according to claim 1, wherein the plate is composed of only one kind of porous material. 2. The oil pan according to claim 1, wherein an average porosity of the porous material gradually increases from a region near the surface toward the internal region. The oil pan according to claim 1, wherein pores are not present on the plate surface. 2. The oil pan according to claim 1, wherein the porous material has a region where the average porosity is maximum in an internal region where the average porosity is large.

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