JP2001124207A - Seal structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive and reliable seal structure. SOLUTION: In the seal structure in which two members are tightened to each other by a tightening member 20 via a sealing member 10, and at least one member is formed of a sheet metal member 6, a projecting part 9 projecting toward another member 4 through the plastic deformation of the tightening member is formed in the vicinity of a passing part 8 formed in the sheet metal member to allow the tightening member to pass.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a seal structure for two members, and more particularly, to a seal structure for an engine cylinder head and a rocker cover.

[0002]

[Related Background Art] In an engine, a valve operating mechanism is provided on a cylinder head.
A rocker cover is mounted on the cylinder head. By the way, lubricating oil is supplied to the valve mechanism for the purpose of lubricating each component such as a camshaft, and the rocker cover scatters the lubricating oil around the camshaft and the like by high-speed operation of each component such as the camshaft. It also has a function to prevent the problem.

[0003] Furthermore, the space inside the rocker cover (hereinafter, referred to as the rocker cover)
Generally, blow-by gas leaking from a gap between the cylinder and the piston is guided to the locker chamber), and the rocker cover also has a role of preventing the blow-by gas from leaking to the surroundings. . For this reason, it is necessary to completely prevent the leakage of lubricating oil and blow-by gas to the outside of the engine, and to seal the rocker chamber, a seal member should be interposed between the cylinder head and the rocker cover. I have to. For example, a groove having a rectangular cross section is formed in the peripheral flange portion of the rocker cover facing the cylinder head, and an elastic annular seal member (gasket) molded in advance to fit the groove is fitted into the groove. A method is known in which the cover is pressed against the cylinder head while being fastened to the cylinder head with a fastening member such as a bolt, thereby compressing the sealing member so that the sealing member is in close contact with the cylinder head and sealed.

However, in such a seal structure in which the sealing member is compressed and deformed to obtain a sealing property, the sealing member which protrudes from the groove due to the compression deformation is broken by the edge of the groove or exceeds the elastic range. When a compressive force is applied to the seal member, the seal member may be set over time (a phenomenon in which elasticity is lost due to fatigue) and the sealability may be impaired, which is not preferable. Further, there is a possibility that the fastening portion such as the bolt of the rocker cover is bent and deformed or damaged.

Therefore, in a rocker cover made of a cast member or a resin member, a part of a bolt boss provided on a flange portion of the rocker cover is protruded to form a seat surface, and the seat surface is brought into contact with a cylinder head. Japanese Patent Application Laid-Open No. 1-118146 discloses a technique in which a flange portion of a rocker cover and a cylinder head are separated from each other by a predetermined amount at a sealing portion so that the sealing member is prevented from being compressed beyond an elastic range to ensure sealing performance. Have been.

[0006]

On the other hand, since the blow-by gas and the lubricating oil are mixed in the rocker chamber as described above, the rocker chamber usually has a gas-liquid separation chamber for separating the blow-by gas and the lubricating oil. Is provided. However, in the case of the rocker cover made of a cast member or a resin member as described above, it is difficult to integrally form such a gas-liquid separation chamber. is not.

For this reason, a technique for manufacturing a rocker cover using a sheet metal member is disclosed in Japanese Utility Model Registration No. 2539847. If the sheet metal member is used in this manner, the rocker cover has high rigidity by welding the plurality of sheet metal members formed by plastic deformation, and the like.
Further, the gas-liquid separation chamber can be easily formed, and the rocker cover can be manufactured at low cost as a whole.

However, when the rocker cover is manufactured from a sheet metal member, since the thickness is constant, it is not possible to integrally form the seating surface by changing the thickness like a cast member or a resin member. It is difficult to form the seat. Therefore, in such a case, Japanese Utility Model Laid-Open No. 4-57653.
As disclosed in Japanese Patent Application Publication, it is possible to regulate the compression height of the seal member by using a spacer, but this method requires a separate spacer, and the manufacturing cost is increased due to an increase in parts and man-hours. This is unfavorable, contrary to the original purpose of reducing manufacturing costs by using sheet metal members.

The present invention has been made to solve such a problem, and an object of the present invention is to provide an inexpensive and highly reliable sealing structure.

[0010]

In order to achieve the above object, according to the first aspect of the present invention, two members are fastened by a fastening member via a sealing member, and at least one member is formed of a sheet metal member. In the structure, a protrusion is formed near the insertion portion formed in the sheet metal member so as to penetrate the fastening member so as to project toward another member by plastically deforming the fastening member.

Therefore, when the sheet metal member is fastened to the other member by the fastening member, the projection having a predetermined height comes into contact with another member, and the seal member is formed in a simple structure using the sheet metal member. It is prevented from being compressed beyond the elastic range between the two members, the seal member protruding due to the compression is preferably prevented from being broken or the seal member being set, so that the sealing property is impaired, and Deformation or breakage of a fastening portion such as a bolt of the rocker cover is also prevented, and a low-cost and highly reliable sealing structure can be realized.

For example, if the seal structure is applied between a rocker cover and a cylinder head of an engine, and the rocker cover is a sheet metal member, a plurality of sheet metal members formed by plastic deformation are welded to each other to form a rocker chamber. The gas-liquid separation chamber can be easily formed, and the sealing property between the rocker cover and the cylinder head is sufficiently ensured, so that leakage of lubricating oil and blow-by gas to the outside can be reliably prevented. As a result, an inexpensive and highly reliable rocker cover seal structure can be obtained.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings. First, a first embodiment will be described. FIG. 1 shows an engine 1 to which a seal structure according to the present invention is applied.

The engine 1 is, for example, an OHC (overhead cam) type gasoline engine. A cylinder head 4 is mounted on a cylinder block 2 and fastened. A valve operating mechanism such as an exhaust valve, a rocker arm, and a camshaft is provided. As shown in the figure, a rocker cover 6 is mounted on the cylinder head 4 to protect these spark plugs and the valve operating mechanism.
Are fastened to the cylinder head 4 by bolts or the like.
Here, the rocker cover 6 is made of a sheet metal member such as a rust-proof steel plate.

By the way, the valve train is provided with the engine 1
Lubricating oil is supplied through an oil passage provided in the
The lubricating oil is scattered around by the high speed rotation of the camshaft. Therefore, the rocker cover 6 also has a function of preventing the scattered lubricating oil from leaking outside. Further, blow-by gas leaking from a gap between the cylinder and the piston is temporarily stored in a space inside the rocker cover 6, that is, the rocker chamber 12 before being sent to the intake system. Also has a role in preventing the blow-by gas from leaking to the outside.

For this reason, the rocker chamber 12 needs to be sealed, and a gasket 10 (seal member) is interposed between the cylinder head 4 and the rocker cover 6. Thereby, the gap between the cylinder head 4 and the rocker cover 6 is sealed, and the airtightness of the rocker chamber 12 is ensured. Hereinafter, the seal structure between the cylinder head 4 and the rocker cover 6 according to the present invention will be described in detail.

Referring to FIG. 2, there is shown a detailed view as viewed from the direction of arrow A in FIG. 1. Further, with reference to FIG. 3, there is shown a first embodiment along the line BB in FIG. Such a cross section is shown. As shown in these figures, a flange 7 is formed to extend outward on a peripheral edge of an outer plate 6a of the rocker cover 6 facing the upper surface of the cylinder head 4, and a bolt (fastening member) ), And an insertion hole (insertion portion) 8 for inserting and fastening the cylinder head 4 to the cylinder head 4.

The insertion hole 8 is a so-called burring hole, and a rising flange (projection) 9 which stands up and extends in parallel with the axis of the hole has a predetermined height h on the outer peripheral edge of the insertion hole 8. It is formed. The standing flange 9 is attached to the outer plate 6.
It can be obtained at the same time by simply punching out a and punching the insertion hole 8, and the processing is extremely easy and low cost.

Further, as shown in FIG.
The space on the inner side is actually divided into upper and lower parts by an inner plate 6b. Specifically, the outer peripheral edge of the inner plate 6b is welded to the outer plate 6a, and the upper chamber has blow-by gas, lubricating oil and And a lower chamber is a rocker chamber 12. The gas-liquid separation chamber 11 is provided with a plurality of fins. In the gas-liquid separation chamber 11, the scattered lubricating oil collides with the fins to form droplets so that blow-by gas is separated. I have.

As shown in FIG. 3, the gasket 10 is interposed between the portion of the flange 7 closer to the rocker chamber 12 than the insertion hole 8 and the upper surface of the cylinder head 4 in a compressed state. Here, the gasket 10 is, for example, the above-described coating-curing-forming gasket (such as CIPG), that is, a gel having adhesiveness at the time of coating, and changes into a rubber having elasticity after a certain period of time in the air. It is a gasket with properties.

Therefore, in practice, the gasket 10 is applied to the rocker cover 6 in advance along the flange 7 so that the material cross-sectional area is constant at a predetermined value, and the gasket 10 becomes rubber-like. Rocker cover 6
Is placed on the upper surface of the cylinder head 4. As a result, the gasket 10 is interposed between the flange 7 and the upper surface of the cylinder head 4 as shown in the figure. The material diameter of the gasket 10 based on the predetermined value of the material cross-sectional area is set to be slightly larger than the predetermined height h of the standing flange 9.

Hereinafter, the function and effect of the thus constructed seal structure will be described. As described above, the outer periphery of the insertion hole 8 formed in the flange 7 has a predetermined height h.
Is formed, and the material diameter of the gasket 10 is slightly larger than the predetermined height h. Therefore, the rocker cover 6 is placed on the upper surface of the cylinder head 4 and the rocker cover 6 is
When the fastening is performed at 0, the flange 7 presses the gasket 10 against the upper surface of the cylinder head 4 and the tip of the flange 9 comes into contact with the upper surface of the cylinder head 4.

As a result, the gasket 10 is no longer pressed against the upper surface of the cylinder head 4 more than necessary by the flange 7 of the rocker cover 6 and is compressed, so that the gasket 10 is not excessively deformed, and the sag occurs with time. Is prevented. Therefore, the gasket 10 can maintain a stable sealing performance satisfactorily without deteriorating the sealing property while maintaining the elasticity.

That is, since the rocker cover 6 is formed of a sheet metal member and the through hole 8 of the bolt 20 is formed as a burring hole and the flange 9 is formed on the outer peripheral edge of the through hole 8, the cost is low but the reliability is high. A seal structure can be realized. Next, a second embodiment will be described.
Here, only the parts different from the first embodiment will be described.

Referring to FIG. 4, there is shown a detailed view as seen from the direction of arrow A in FIG. 1. Further, with reference to FIG. 5, in the second embodiment along the line CC in FIG. Such a cross section is shown. As shown in these drawings, also in the second embodiment, similarly to the case of the first embodiment, the bolt 20 is inserted through the flange 7 of the outer plate 6a of the rocker cover 6 so that the cylinder 20 is inserted. An insertion hole 8 to be fastened to the head 4 is formed.

However, in the second embodiment,
A bead (projection) 14 formed by deep drawing is formed in a cross shape or the like with a predetermined height h on the outer periphery of the insertion hole 8. Since the bead 14 simply draws the outer plate 6a at the time of press working, it is easier to secure the predetermined height h than the above-described burring work, but at the same low cost as the burring work.

Even when the bead 14 is formed on the outer periphery of the insertion hole 8 in this manner, the rocker cover 6 is attached to the cylinder head 4 by the bolt 2 similarly to the first embodiment.
When it is tightened at 0, the tip of the bead 14 comes into contact with the upper surface of the cylinder head 4 while the flange 7 presses the gasket 10 against the upper surface of the cylinder head 4. This allows
Similarly to the above, the gasket 10 is prevented from being excessively deformed, is prevented from being set over time, and has a stable sealing performance without impairing the sealing property while maintaining the elasticity. Will be held.

That is, by forming the rocker cover 6 by a sheet metal member and forming the beads 14 on the outer periphery of the insertion hole 8 of the bolt 20, a highly reliable sealing structure can be realized at low cost. Next, a third embodiment will be described. Here, only the portions different from the first embodiment will be described.

Referring to FIG. 6, there is shown a detailed view as viewed from the direction of arrow A in FIG. 1. Further, with reference to FIG. 7, a third embodiment along the line DD in FIG. 6 is shown. Such a cross section is shown. As shown in these drawings, in the third embodiment, as in the case of the first embodiment, the insertion hole 8 is a so-called burring hole. Is formed with a standing flange (projection) 9 standing up and extending parallel to the axis of the hole with a predetermined height h.

Also, in the third embodiment, as shown in FIG. 7, the space inside the rocker cover 6 is divided into upper and lower parts by an inner plate 16, and the upper chamber is also made of lubricating oil such as blow-by gas. A gas-liquid separation chamber 11 for separating oil is provided, and a lower chamber is a rocker chamber 12. However, unlike the case of the first embodiment, a flange 16a is formed on the outer peripheral edge of the inner plate 16 so as to extend in parallel with the flange 7 of the rocker cover 6, and the inner plate 16 is welded. And is fitted on the inner side of the outer plate 6a.
Further, an escape hole 17 for penetrating the standing flange 9 is formed in the flange 16a.

Then, as shown in FIG.
8 is interposed in a compressed state between a portion closer to the rocker chamber 12 than the insertion hole 8 of the flange 7 and the upper surface of the flange 16a.
Is compressed and interposed between the lower surface of the flange 16a and the upper surface of the cylinder head 4 along the axis. That is, in the third embodiment, the inner plate 16 is supported between the flange 7 of the rocker cover 6 and the upper surface of the cylinder head 4 such that the gasket 18 and the gasket 19 sandwich the flange 16a.

As a result, in the third embodiment, the same stable sealing performance as in the first embodiment can be obtained by the action of the standing flange 9. Since the inner plate 16 does not need to be welded to the outer plate 6a, the inner plate 16 does not need to be sub-assembled to the outer plate 6a in advance. It is possible to make the receiving shape compact, and it is possible to realize a highly reliable sealing structure while further reducing costs.

Next, a fourth embodiment will be described.
Here, only the parts different from the third embodiment will be described. Referring to FIG. 8, there is shown a detailed view as viewed in the direction of arrow A in FIG. 1. Further, with reference to FIG. 9, a cross-section according to the fourth embodiment along line EE in FIG. It is shown.

As shown in these figures, also in the fourth embodiment, similar to the third embodiment,
A flange 16a is formed on the outer peripheral edge of the inner plate 16 so as to extend in parallel with the flange 7 of the rocker cover 6, and the inner plate 16 is fitted on the inner side of the outer plate 6a without welding, and the gasket 18 The inner plate 16 is supported with the gasket 19 sandwiching the flange 16a.

However, in the fourth embodiment,
Unlike the case of the third embodiment, an insertion hole 22 is formed in the flange 16 a of the inner plate 16, and the insertion hole 22 is a so-called burring hole. A standing flange 23 extending substantially parallel to the axis of the insertion hole 22 is formed with a predetermined height h / 2. Further, an insertion hole 8 'is formed in the flange 7 of the outer plate 6a so as to be substantially concentric with the insertion hole 22 and larger in diameter than the insertion hole 22. The insertion hole 8' is also a burring hole. A standing flange 9 'extending substantially parallel to the axis of the insertion hole 8' is formed on the outer peripheral edge of the insertion hole 8 ', also having a predetermined height h / 2.

As shown in FIG. 9, the tip of the standing flange 9 'is in contact with the flange 16a, and the tip of the standing flange 23 is in contact with the upper surface of the cylinder head 4.
Thereby, also in the fourth embodiment, the same stable sealing performance as that in the third embodiment can be obtained by the action of the standing flange 23 and the standing flange 9 ′. In this case, since the inner plate 16 is fixed in contact with the upper surface of the cylinder head 4 and the outer plate 6a, noise and the like due to the vibration of the inner plate 16 can be reduced, and the gasket 18, 19 can be prevented from decreasing in durability.

Next, a fifth embodiment will be described.
Here, only the portions different from the fourth embodiment will be described. Referring to FIG. 10, there is shown a detailed view as viewed in the direction of arrow A in FIG. 1. Further, with reference to FIG. 11, a cross section according to the fifth embodiment along line FF in FIG. It is shown.

As shown in these figures, in the fifth embodiment, the flange 7 of the rocker cover 6 is provided on the outer peripheral edge of the inner plate 16 as in the third and fourth embodiments.
The inner plate 16 is fitted to the inner side of the outer plate 6a without welding, and the inner plate 16 is supported with the gasket 18 and the gasket 19 sandwiching the flange 16a. ing.

However, in the fifth embodiment,
Unlike the case of the fourth embodiment, an insertion hole 22 ′ is formed in the flange 16 a of the inner plate 16, and the insertion hole 2
A bead 2 similar to that of the second embodiment is provided on the outer circumference of 2 ′.
4, for example, as shown in FIG. 10, is formed radially in three directions and has a predetermined height h / 2. Further, an insertion hole 8 is formed in the flange 7 of the outer plate 6 a so as to be concentric with the insertion hole 22 ′.
4 'is also formed radially in three directions with a predetermined height h / 2. These beads 24 and beads 14 '
As in the second embodiment, since the deep drawing is simply performed during the press working, the predetermined height h / 2 can be easily secured at a lower cost than in the burring work.

Then, as shown in FIG.
4 'is in contact with the flange 16a, and the bead 24 is in contact with the upper surface of the cylinder head 4. As shown in FIG. 10, the bead 14 'and the bead 24 are formed at a predetermined angle around the center of the insertion hole so that the bead 14' does not overlap with the bead 24 and directly contacts the surface of the flange 16a. . Thereby, also in the case of the fifth embodiment, the same effect as that of the fourth embodiment can be obtained.

Preferably, a shallow groove for guiding and positioning the gasket 10, the gasket 18, or the gasket 19 may be formed in the flange 7 or the flange 16a, so that the reliability is further improved. A seal structure is realized.

[0042]

As described above in detail, according to the sealing structure of the first aspect of the present invention, at least one of the two members is a sheet metal member, and the sheet metal member is inserted into the sheet metal member so that the fastening member can be inserted. In the vicinity of the formed insertion portion, a projection projecting toward another member is formed by plastically deforming the fastening member, so that when the sheet metal member is fastened to the other member by the fastening member, a predetermined A protruding portion having a height can be brought into contact with another member, a simple structure using a sheet metal member can prevent the seal member from being compressed beyond the elastic range between the two members, and can protrude by compression. It is possible to preferably prevent the sealing property from being impaired due to breakage of the sealed member or occurrence of set on the sealing member, and
Deformation or breakage of a fastening portion such as a bolt of the rocker cover can be prevented, and a low-cost and highly reliable sealing structure can be realized.

Therefore, for example, if the seal structure is applied between the rocker cover of the engine and the cylinder head, and the rocker cover is a sheet metal member, a plurality of sheet metal members formed by plastic deformation are welded together. The gas-liquid separation chamber can be easily formed in the locker chamber, and the sealing performance between the rocker cover and the cylinder head can be sufficiently ensured to prevent the leakage of lubricating oil and blow-by gas to the outside. A highly reliable rocker cover seal structure can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing an engine to which a seal structure according to the present invention is applied.

FIG. 2 is a diagram viewed from the direction of arrow A in FIG. 1, and is a diagram illustrating details of a seal structure according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a cross section taken along line BB of FIG. 2;

FIG. 4 is a view seen from the direction of arrow A in FIG. 1, and is a view showing details of a seal structure according to a second embodiment of the present invention.

FIG. 5 is a diagram showing a cross section taken along line CC of FIG. 4;

FIG. 6 is a diagram viewed from the direction of arrow A in FIG. 1, and is a diagram illustrating details of a seal structure according to a third embodiment of the present invention.

FIG. 7 is a diagram showing a cross section taken along line DD of FIG. 6;

FIG. 8 is a diagram viewed from the direction of arrow A in FIG. 1, and is a diagram illustrating details of a seal structure according to a fourth embodiment of the present invention.

FIG. 9 is a diagram showing a cross section along the line EE in FIG. 8;

FIG. 10 is a view as viewed from a direction indicated by an arrow A in FIG. 1, and is a view showing details of a seal structure according to a fifth embodiment of the present invention.

11 is a diagram showing a cross section along the line FF in FIG. 10;

[Description of Signs] 1 Engine 4 Cylinder head 6 Rocker cover (sheet metal member) 7 Flange 8 Insertion hole (insertion part) 9 Standing flange (projection) 10 Gasket (seal member) 14 Bead (projection) 20 Bolt (fastening member) )

Claims (1)

[Claims] 1. A sealing structure in which two members are fastened by a fastening member via a sealing member, and at least one of the members is a sealing structure made of a sheet metal member, and an insertion formed in the sheet metal member to insert the fastening member. And a projection formed in the vicinity of the insertion portion by projecting toward another member by plastically deforming the fastening member.