JPH10103152A - Mounting structure for oil pan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a problematic point that a time is taken for hardening a liquid state gasket, a surface pressure between an oil pan flange and a block flange must be ensured by decreasing a bolt space. SOLUTION: In an oil pan flange 2 of an oil pan 2, a protruded part 6 is continuously formed in the total periphery in the width direction center of an upper surface 3 which is a mounting surface. In a block flange, a rib is protruded to an upper surface (back surface) in an opposite side to the mounting surface. In this way, a surface pressure between the oil pan flange 2 and the flange of a cylinder block is increased, a sealing property between bolts is enhanced. Consequently, a pitch (space) of the mounting bolt can be widely set, by this amount, the mounting bolt 5 can be reduced. Further, between a step difference 7 in both sides of the protruded part 6 charged with the liquid state gasket and the block flange, by a space opened with the sideward, the liquid state gasket is hardened in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil pan mounting structure, and more particularly to an oil mounting method for mounting an oil pan on a cylinder block by fixing an oil pan flange with mounting bolts with a liquid gasket interposed between block flanges at a lower end of a cylinder block. The present invention relates to a bread mounting structure.

[0002]

2. Description of the Related Art For example, in an internal combustion engine for an automobile, oil is supplied to a crankshaft, a cylinder bore, a piston pin, a valve mechanism, and the like to perform lubrication and cooling. And is circulated by pumping again to each part by an oil pump or the like.

[0003] This type of oil pan is, for example,
As shown in Japanese Patent No. 101060, there is known an oil pan in which a seal groove is provided between bolt mounting holes in a flange formed on a peripheral portion of an oil pan. In the oil pan mounting structure described in this publication, since the seal groove is formed at the center in the width direction of the oil pan flange, the oil pan flange is fastened to the block flange formed at the lower end of the cylinder block by the mounting bolt. In this case, both side edges of the seal groove of the oil pan flange come into contact with the block flange.

After the oil pan flange is fixed to the block flange by fastening the mounting bolts, the liquid gasket injected into the seal groove is hardened in the seal groove to seal between the oil pan flange and the block flange. I do.

[0005]

However, in the above-described conventional oil pan mounting structure, since both side edges of the seal groove provided in the oil pan flange abut against the block flange, the surface pressure generated by fastening the mounting bolts. Was low.

[0006] The liquid gasket injected into the seal groove has a property of being cured by moisture contained in the air, but after assembly, it is defined by both side edges of the seal groove and a block flange. Since the space remains filled, it is kept in a state where it is difficult to contact with air, and it takes a considerable time from when the oil pan flange is attached to the block flange to when it hardens.

[0007] If the curing of the liquid gasket is delayed in this manner, it takes time until the seal width between the oil pan flange and the block flange is sufficiently ensured. Will do. Therefore, in order to reduce the time after assembly, the pitch (spacing) of the mounting bolts for fastening the oil pan flange to the block flange is reduced to increase the surface pressure between both side edges of the seal groove and the block flange. I had to do it. For this reason, conventionally, the number of mounting bolts increases, and assembling work takes an extra time, which makes it difficult to improve production efficiency.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide an oil pan mounting structure configured to increase the surface pressure between an oil pan flange and a block flange in which a liquid gasket is interposed. .

[0009]

In order to solve the above problems, the present invention has the following features. The present invention provides an oil pan mounting structure in which a liquid gasket is interposed between a block flange at a lower end of a cylinder block and an oil pan flange is fixed with mounting bolts and the oil pan is mounted on the cylinder block. A protrusion that contacts the block flange is provided on the entire circumference at the center in the width direction, and a rib corresponding to the contact position of the protrusion extends on the back surface of the block flange, and the mounting bolt extends along the rib. The oil pan flange and the block are fastened by fastening a mounting bolt to a bolt fastening portion of the block flange by bringing a protrusion of the oil pan flange into contact with the block flange. When connecting the flanges, the liquid gasket applied to the protrusions It is characterized in that the structure to be filled into the formed stepped portions were.

Therefore, according to the present invention, the surface pressure after assembly of the bolt against the block flange is secured between the bolts by providing a projection in contact with the block flange all around the widthwise center of the end face of the oil pan flange. In addition, the liquid gasket is filled into the step portions formed on both sides of the projection and the liquid gasket is easily exposed to air even after assembly, so that the curing of the liquid gasket can be promoted.

Further, a rib is formed on the back surface of the block flange corresponding to the contact position of the projection of the oil pan flange, and a bolt fastening portion is provided along the rib. The surface pressure at the time of fastening the mounting bolt is increased, and sufficient sealing properties can be obtained.

Further, since the sealing property between the bolted portions is ensured, the pitch (spacing) of the mounting bolts can be made wider than that of the conventional bolts, and the number of mounting bolts can be reduced.
The work in the assembly process can be simplified accordingly.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of an oil pan to which an embodiment of an oil pan mounting structure is applied.

The oil pan 1 is made of iron, and has an oil pan flange 2 formed all around the upper peripheral portion. The upper surface 3 of the oil pan flange 2 is a mounting surface for the oil pan. The oil pan flange 2 is provided with bolt holes 4 at predetermined intervals. The oil pan flange 2 is attached to a lower part of a cylinder block (not shown) by a mounting bolt 5 inserted into a bolt hole 4.

The upper surface 3 of the oil pan flange 2 is provided with a projection 6 and a circular projection 9 which are in contact with the mounting surface of the cylinder block, all around. 2 is an enlarged plan view showing the upper surface 3 of the oil pan flange 2, FIG. 3 is a longitudinal sectional view along the line AA in FIG. 2, and FIG. 4 is a longitudinal sectional view along the line BB in FIG. is there.

The protrusion 6 formed on the upper surface 3 of the oil pan flange 2 is formed so as to protrude toward the center in the width direction of the oil pan flange 2, and has a step 7 lower on both sides. Thus, on the upper surface 3 of the oil pan flange 2, one protrusion 6 is formed continuously along the periphery of the upper opening of the oil pan 1.

The steps 7 formed on both sides of the projection 6 form a space filled with a liquid gasket and function as a seat surface as described later. In addition, the protrusion 6 functions as a reinforcing rib that enhances the strength of the oil pan flange 2 together with the curved portion 8 formed at the end of the oil pan flange 2.

Further, a circular projection 9 having a larger diameter than the projection 6 is formed around the bolt hole 4. A circular recess 10 is formed on the lower surface of the circular projection 9 so that the head of the mounting bolt 5 is fitted. In addition, the circular projection 9
Is formed continuously with a protrusion 6 extending on the upper surface 3 of the oil pan flange 2. Bolt holes 4 provided at the center of the circular protrusion 9 are provided at regular intervals (intervals) L. I have. The pitch (interval) L is set to a predetermined size according to the surface pressure acting on the oil pan flange 2 after assembly.

In this embodiment, the single protrusion 6 and the circular protrusion 9 extending to the oil pan flange 2 are in contact with the flange of the cylinder block. Surface pressure increases. As a result, a sufficient sealing property can be obtained by securing the surface pressure between the bolts, so that it is not necessary to narrow the pitch (interval) L of the mounting bolts 5 as in the related art. Moreover, since the liquid gasket is filled in the steps 7 formed on both sides of the projection 6, the liquid gasket after assembly is kept in contact with air as described later, and the curing time of the liquid gasket is reduced. .

FIG. 5 is a plan view of a block flange 11 formed on the lower peripheral portion of the cylinder block, FIG. 6 is a longitudinal sectional view along the line CC in FIG. 5, and FIG. 7 is a line DD in FIG. It is a longitudinal cross-sectional view along. The block flange 11 of the cylinder block (not shown) is made of an aluminum alloy and has a contour corresponding to the oil pan flange 2, and the upper surface (rear surface) opposite to the mounting surface with which the oil pan flange 2 contacts.
A rib 13 protrudes at the center in the width direction of the projection 12. The rib 13 is formed so as to extend all around the block flange 11, and the protrusion 6 of the oil pan flange 2 is formed.
Therefore, the pressure resistance of the block flange 11 is increased to withstand the surface pressure after assembly. Therefore, when the oil pan flange 2 is fastened to the block flange 11, even if the block flange 11 is strongly pressed by the tightening of the mounting bolt 5, the block flange 11 is not deformed, and the surface pressure generated between the oil pan flange 2 and the oil pan flange 2 can be secured.

Further, a circular bolt fastening portion 1 is formed on the upper surface (back surface) 12 of the block flange 11 along the rib 13.
4 are provided at predetermined intervals. This bolt fastening part 1
At the center of 4, a screw hole 15 in which a female screw with which the mounting bolt 5 is screwed from below is formed.

The screw hole 15 is provided at a position corresponding to the bolt hole 4 of the oil pan flange 2. That is,
The pitch (interval) L between the screw holes 15 is the same as the pitch of the bolt holes 4 of the oil pan flange 2.
8 is a longitudinal sectional view showing a state before fixing the oil pan flange 2 to the block flange 11, and FIG. 9 is a longitudinal sectional view showing a state where the oil pan flange 2 is fixed to the block flange 11.

When the oil pan flange 2 is fixed to the block flange 11, a liquid gasket 16 is applied to the upper surfaces of the protrusion 6 and the circular protrusion 9 of the oil pan flange 2.
Next, the protrusion 6 and the circular protrusion 9 of the oil pan flange 2 are pressed against the lower surface of the block flange 11. Then, the mounting bolt 5 is inserted from below into the bolt hole 4 and screwed into the screw hole 15 of the bolt fastening portion 14 to be tightened.

As a result, the protrusion 6 and the circular protrusion 9 of the oil pan flange 2 abut against the block flange 11 and are fixed. Since the block flange 11 is provided so that the rib 13 corresponds to the protrusion 6 of the oil pan flange 2, the pressure resistance is increased. Therefore, when the mounting bolt 5 is screwed into the screw hole 15, when the oil pan flange 2 and the block flange 11 are fastened so that the protrusion 6 and the circular protrusion 9 come into contact with the block flange 11, the protrusion is formed. A stronger surface pressure acts between the block flange 6 and the circular protrusion 9 and the block flange 11.

The liquid gasket 16 applied to the upper surfaces of the projections 6 and the circular projections 9 receives a compressive stress between the projections 6 and the circular projections 9 and the block flange 11, so that
With the tightening of the mounting bolt 5, the protrusion 6 and the circular protrusion 9
Extruded on both sides. Then, the protrusion 6 and the circular protrusion 9
The liquid gasket 16 that has moved to both sides in the process of contacting the block flange 11 is in a state in which the space formed between the step 7 having a side opening and the block flange 11 is filled without gaps. In this case, the liquid gasket 1 is provided between the protrusion 6 and the circular protrusion 9 and between the block flange 11.
6 and the space between the step 7 and the block flange 11 is also sealed.

Furthermore, the space between the step 7 filled with the liquid gasket 16 and the block flange 11 is not a closed space but a space opened on the side. Therefore, the liquid gasket 16 filled in the step 7 can be brought into contact with air even after assembling, and is hardened in a short time by the moisture contained in the air.

As described above, the liquid gasket 16 is
Is filled between the flange 7 and the step 7 formed on both sides of the liquid gasket, the curing time of the liquid gasket 16 is shorter than that of the conventional liquid gasket which is filled in a closed space. Therefore, the time until the liquid gasket 16 is hardened after the oil pan 1 is mounted on the bottom of the cylinder block (not shown) is shortened, and the production efficiency is increased.

FIG. 10 is a graph showing the relationship between the pitch (spacing) of the mounting bolts 5 and the rigidity between the bolts. In FIG. 10, the characteristics of the conventional mounting structure are shown by solid lines, and the characteristics of the mounting structure of this embodiment are shown by dashed lines. From this graph, it can be seen that in the mounting structure of this embodiment, the bolt pitch can be set larger than that of the conventional mounting structure to obtain the same rigidity between bolts.

As described above, the protrusion 6 is provided on the entire circumference of the oil pan flange 2, and the upper surface (back surface) of the block flange 11 is provided.
Since the ribs 13 corresponding to the protruding portions 6 are provided on the entire circumference of 12, the surface pressure between the bolts is secured, and a sufficient sealing property is obtained. That is, even if the pitch (interval) L of the mounting bolts 5 is increased from La to Lb (La <Lb), sufficient rigidity between the bolts can be obtained. Can be reduced.

Therefore, the pitch (interval) L of the bolt holes 4 into which the mounting bolts 5 are inserted can be set wider than that of the conventional bolt holes. The work efficiency at the time is increased.

[0031]

As described above, according to the present invention, the surface pressure after assembling between the bolts against the block flange is provided by providing a projection abutting on the block flange all around the widthwise center of the end face of the oil pan flange. The liquid gasket is filled in the step portions formed on both sides of the projection, and the liquid gasket is easily exposed to air even after the assembling, so that the hardening of the liquid gasket can be promoted. Therefore, the time from when the oil pan is attached to the cylinder block until the liquid gasket is hardened and the sealing property is secured is shortened, and the test operation can be performed immediately after the engine is assembled.

Further, a rib is formed on the back surface of the block flange so as to extend corresponding to the contact position of the projection, and a bolt fastening portion is provided along the rib.
The surface pressure at the time of fastening the mounting bolts between the bolt fastening portions is increased, and sufficient sealing properties can be obtained. This makes it possible to increase the pitch of the mounting bolts and reduce the number of mounting bolts. Therefore, the pitch of the mounting bolts can be widened and the number of mounting bolts can be reduced, so that the work efficiency of the assembling process can be increased accordingly.

[Brief description of the drawings]

FIG. 1 is a perspective view of an oil pan to which an embodiment of an oil pan mounting structure according to the present invention is applied.

FIG. 2 is an enlarged plan view showing an upper surface of an oil pan flange.

FIG. 3 is a longitudinal sectional view taken along line AA in FIG.

FIG. 4 is a longitudinal sectional view taken along line BB in FIG. 2;

FIG. 5 is a plan view of a block flange formed on a lower peripheral portion of the cylinder block.

FIG. 6 is a longitudinal sectional view taken along line CC in FIG.

FIG. 7 is a longitudinal sectional view taken along line DD in FIG.

FIG. 8 is a longitudinal sectional view showing a state before an oil pan flange is fixed to a block flange.

FIG. 9 is a longitudinal sectional view showing a state where an oil pan flange is fixed to a block flange.

FIG. 10 is a graph showing a relationship between pitch (spacing) of mounting bolts and rigidity between bolts.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Oil pan 2 Oil pan flange 4 Bolt hole 5 Mounting bolt 6 Projection 7 Step 9 Circular projection 10 Circular recess 11 Block flange 13 Rib 14 Bolt fastening part 15 Screw hole 16 Liquid gasket

Claims (1)

[Claims] 1. An oil pan mounting structure for mounting an oil pan to a cylinder block by fixing an oil pan flange to the cylinder block with a liquid gasket interposed between block flanges at a lower end of a cylinder block with mounting bolts. Protrusions that contact the block flange are provided on the entire periphery in the center in the width direction of the surface, and a rib corresponding to the contact position of the protrusion extends on the back surface of the block flange, and the mounting is performed along the rib. A bolt fastening portion to which a bolt is fastened, wherein a protrusion of the oil pan flange is brought into contact with the block flange, and the mounting bolt is fastened to the bolt fastening portion of the block flange, and the oil pan flange and the oil pan flange are tightened. When joining the block flanges, the liquid gasket applied to the projections A mounting structure for an oil pan, characterized in that the structure is filled in a step portion formed on both sides.