JP2015161390A - Seal structure with metal gasket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seal structure in which salt water outside a housing is difficult to reach a seal line with a metal gasket, and which suppresses corrosion of the housing due to residence of salt water.SOLUTION: In a structure sealing the gap between a pair of housings with a metal gasket including a seal bead, a shield film made of grease, which prevents salt water outside the housing from reaching the vicinity of a seal line set by pressure-welding the metal gasket to the housing, is formed outside the seal line. The grease is supplied from the inside of the seal line to the outside through a pierced hole preliminarily provided in the metal gasket. The pierced hole is provided on the circumference of the metal gasket and in the vicinity of a coupling place of an assembly bolt.

Description

  The present invention relates to a seal structure using a metal gasket. The seal structure of the present invention is used, for example, in the field related to automobiles or used in other fields.

  For example, in the case of a metal gasket for automobiles, a salt spray test may be performed as a specification evaluation item in preparation for a situation where the automobile travels in a beach area. In this case, as shown in FIG. 5A, if the other casing 61 to which the metal gasket 51 is attached is made of an aluminum material (including an aluminum alloy, the same applies hereinafter), the gap between the metal gasket 51 and the casing 61 When salt water (not shown) is deposited (attached) on 71 and is repeatedly dried and wet, corrosion (crevice corrosion) of the aluminum material due to salt water (difference in ion concentration) occurs. The metal gasket 51 exerts a sealing function by the reaction force of the portion that contacts the casing 61. However, when the corroded portion F of the casing 61 penetrates the seal line SL as shown in FIG. It will be damaged.

  The casing 61 is corroded even if it is made of an iron-based material, but aluminum (Al) is easily corroded because it is a metal having a higher ionization tendency than iron-based (Fe).

Al ³⁺ + 3H ₂ O → Al (OH) ₃ + 3H ⁺

  Further, in order to suppress the corrosion of the casing due to the retention of salt water, it is conceivable to stack two metal gaskets as shown in Patent Document 5 below, and in this case, an excellent corrosion suppressing effect can be exhibited. However, since two metal gaskets are required, there is an inconvenience that the component cost increases.

Japanese Patent Laid-Open No. 7-224938 JP-A-11-241769 JP 2008-164156 A JP 2009-156382 A JP2013-36607A (FIG. 5)

  In view of the above, the present invention has a structure in which salt water outside the housing does not easily reach the seal line of the metal gasket, and the housing is less likely to corrode due to salt water retention, and the sealing function is extended over a long period of time. It is an object of the present invention to provide a seal structure with a metal gasket having a structure that is maintained in a stable manner.

  In order to achieve the above object, a seal structure according to claim 1 of the present invention is a structure in which a pair of casings is sealed with a metal gasket having a seal bead, and the metal gasket is in pressure contact with the casing. A shielding film made of grease that suppresses salt water outside the casing from reaching a seal line to be set is formed outside the seal line.

  The seal structure according to claim 2 of the present invention is the seal structure according to claim 1, wherein the metal gasket has a laminated structure in which a rubber layer is attached to the surface of a metal substrate.

  The seal structure according to claim 3 of the present invention is the seal structure according to claim 1 or 2, wherein the grease passes through a pierce hole provided in advance in the metal gasket from the inside to the outside of the seal line. It is characterized by being supplied to.

  The seal structure according to claim 4 of the present invention is the seal structure according to claim 3, wherein the pierce hole is provided in the vicinity of the fastening position of the assembly bolt on the circumference of the metal gasket. And

  Furthermore, the seal structure according to claim 5 of the present invention is the seal structure according to any one of claims 1 to 4, wherein the metal gasket is first to fourth from the outside to the inside of the housing. The first and third seal lines are set by pressing the metal gasket against one of the casings, and the second and fourth seal lines are set by the metal gasket. The second seal line in the metal gasket is set by press-contacting to the other casing, and a portion from the first seal line to the second seal line in the metal gasket forms a slope portion having a linear cross section. A portion extending from the third seal line to the fourth seal line forms a full bead with an arc cross section, A first piercing hole is provided in the outer slope of the door and a second piercing hole is provided in the slope, and the first sealing gap surrounded by the full bead and the other casing, and the slope, the outer slope and the one casing. Grease is filled in each of the second sealed gaps surrounded by the body, and the grease filled in the first sealed gap flows out to the second sealed gap via the first pierced hole, and in the second sealed gap The grease flows out to the outside of the second seal line and the outside of the first seal line through the second piercing hole.

  In the seal structure of the present invention having the above configuration, since a shielding film made of grease is formed outside the seal line, the presence of the shielding film made of grease allows salt water outside the housing to reach the vicinity of the seal line. Hard to reach. The metal gasket may be composed of a single metal plate, but is generally composed of a laminated structure in which a rubber layer is attached to the surface of a metal substrate in order to improve sealing performance. It is preferable to supply the grease from the inside to the outside of the seal line via a pierced hole provided in advance in the metal gasket. According to this, the grease is squeezed out using the compression force at the time of gasket compression. It is possible to supply outside the line. Since the compressive force is large at and near the fastening location of the assembly bolt, it is preferable to provide the piercing hole on the circumference of the metal gasket and in the vicinity of the fastening location of the assembly bolt.

  In the metal gasket according to the present invention, for example, first to fourth seal lines are sequentially set from the outside to the inside of the housing. Of these, the first and third seal lines are set by pressing the metal gasket against one casing, and the second and fourth seal lines are set by pressing the metal gasket against the other casing. Further, the portion from the first seal line to the second seal line in the metal gasket is a sloped portion having a linear cross section, and the portion from the second seal line through the third seal line to the fourth seal line in the metal gasket is A full bead with an arc cross section is used. In this case, the first pierced hole is provided in the outer slope of the full bead, the second pierced hole is provided in the slope part, the first sealing gap surrounded by the full bead and the other casing is filled with grease, the slope part, It is also preferable to fill the second sealing gap surrounded by the outer slope and one casing with grease, and according to this, when the gasket is compressed, the grease filled in the first sealing gap passes through the first piercing hole. And the grease in the second sealing gap flows out to the outside of the second seal line and the outside of the first seal line via the second piercing hole, so that the outside of the first seal line. The grease is held at any location outside the second seal line, outside the third seal line, and outside the fourth seal line.

  The present invention has the following effects.

  That is, in the present invention, as described above, since a shielding film made of grease is formed outside the seal line, salt water outside the housing reaches the vicinity of the seal line due to the presence of the shielding film made of grease. Hard to do. Accordingly, the salt water outside the housing hardly reaches the seal line, and therefore the housing is less likely to corrode due to the salt water remaining on the seal line, so that the sealing function by the metal gasket can be maintained for a long period of time.

  In addition, by using a metal gasket having a laminated structure in which a rubber layer is attached to the surface of a metal substrate, the sealing performance of the gasket itself can be enhanced, and grease is passed through a pierce hole provided in advance in the metal gasket. By supplying from the inside to the outside of the seal line, grease can be automatically supplied to the outside of the seal line when the gasket is compressed, and the amount of grease supply can be increased by providing a pierce hole near the fastening point of the assembly bolt Can do.

  In addition, when the gasket has the specific shape described above, the first pierced hole is provided in the outer slope of the full bead, the second pierced hole is provided in the slope, and grease is applied to the first sealing gap surrounded by the full bead and the other casing. The grease filled in the first sealed gap is filled via the first pierced hole when the gasket is compressed by filling the second sealed gap surrounded by the slope, the outer slope, and one housing. The grease flows out into the second sealing gap, and the grease in the second sealing gap flows out to the outside of the second seal line and the outside of the first seal line via the second piercing hole. Therefore, grease can be held at any location outside the first seal line, outside the second seal line, outside the third seal line, and outside the fourth seal line. Thus, the salt water resistance of the gasket or casing can be increased.

The top view of the metal gasket used for the seal structure which concerns on the Example of this invention (A) is principal part sectional drawing which shows the state before compression at the time of mounting | wearing with the same gasket, Comprising: CC sectional expanded view in FIG. 1, (B) is the principal part which shows the state after compression at the time of mounting | wearing with the same gasket. Cross section (A) is principal part sectional drawing which shows the state before the compression at the time of mounting | wearing with the gasket, Comprising: DD sectional view taken on the line in FIG. 1, (B) is the principal part which shows the state after compression at the time of mounting | wearing with the gasket Cross section Explanatory drawing showing the laminated structure of the gasket (A) is principal part sectional drawing which shows the state after compression at the time of mounting | wearing with the gasket which concerns on a prior art example, (B) is principal part sectional drawing which shows the malfunction occurrence state of the gasket.

The present invention includes the following embodiments.
(1) The present invention is used in the field of gaskets used in automobiles and the like, and particularly used in a case where an electronic component is incorporated (stored) in a housing.
(2) As a configuration of the present invention, grease is held in the gasket. The type of grease is not required.
(3) As an effect of the present invention, by holding grease on the outer peripheral side of the gasket seal line, H ₂ O and NaCl, which are corrosion influencing factors, are blocked, and Al corrosion (corrosion rate) is reduced. It is possible to extend the life of the salt water sealing function.
(4) A metal gasket in which an elastic body is coated on a substrate is used. Stainless steel, cold rolled steel sheet, galvanized steel sheet or aluminum plywood is used as a base material. The elastic body (rubber compound) is a synthetic rubber sheet (including foamed rubber) containing at least one of nitrile rubber, styrene butadiene rubber, fluorine rubber, acrylic rubber, and silicon rubber.
(5) Aiming at reducing the compression resistance of grease by preventing grease from piercing holes during bead compression (preventing deterioration of bead compressibility). Pierce holes are provided in the vicinity of the bolts (because the bead compression amount is large in the vicinity of the bolts, the compression resistance can be effectively reduced).

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an overall plan view of a metal gasket 11 used in a seal structure according to an embodiment of the present invention, and its CC line enlarged section is shown in FIG. 2 (A) and its DD line enlarged section is shown. 3 (A). FIG. 2A shows a state before the gasket 11 is compressed, and when the gasket 11 is compressed in the thickness direction with a pair of housings (housing or flanges) 21 and 31, it becomes as shown in FIG. 2B. . Similarly, FIG. 3A shows a state before the gasket 11 is compressed, and when the gasket 11 is compressed in the thickness direction with a pair of casings 21 and 31, the result is as shown in FIG. As shown in FIG. 4, the gasket 11 has a laminated structure in which rubber layers 13 are attached (vulcanized and bonded) to both sides of the metal substrate 12 in the thickness direction. In FIG. 2 and FIG. It is drawn in.

As shown in FIG. 2, the seal structure according to this embodiment seals a gap between a pair of housings 21 and 31 with a metal gasket 11 having a seal bead, etc. A seal line SL (SL _{1 to} SL ₄ ) is set over the entire circumference of the gasket by strongly pressing the casings 21 and 31 with a seal bead or the like, and the main seal function is exhibited in the seal line SL. On the other hand, the pair of casings 21 and 31 are each formed of an aluminum material. Therefore, the following measures are taken so that the casings 21 and 31 made of aluminum are less likely to be corroded by salt water on the seal line SL.

  That is, as shown in FIG. 2 (B), when the metal gasket 11 is compressed and installed, a shield made of grease G is used to prevent salt water (not shown) outside the housing O from reaching the seal line SL. The film 41 is formed on the outer side (outer peripheral side, left side in the figure) of the seal line SL. Further, as shown in FIGS. 3A and 3B, the grease G passes from the inner side (inner peripheral side, right side in the figure) to the outer side of the seal line SL through the piercing holes 14 and 15 provided in the metal gasket 11 in advance. It is supposed to be supplied. Further, as shown in FIG. 1, the piercing holes 14 and 15 are provided in the vicinity of the bolt hole 16 which is a fastening portion of the assembly bolt on the circumference of the metal gasket 11. The piercing holes 14 and 15 are small holes provided so as to penetrate the metal gasket 11 in the thickness direction.

In addition, as shown in FIG. 2B, the metal gasket 11 in the present embodiment has first to fourth seal lines from the outside (left side in the figure) to the inside (right side in the figure) of the casings 21 and 31. SL _{1 to} SL ₄ are sequentially set, and among these, odd-numbered first and third seal lines SL ₁ and SL ₃ are set by pressing the metal gasket 11 against one casing 21, and even-numbered The second and fourth seal lines SL ₂ and SL ₄ are set by pressing the metal gasket 11 against the other casing 31. FIG. 2B also illustrates the surface pressure generation situation (distribution) of these seal lines SL _{1 to} SL ₄ .

The metal portion from the first seal line SL ₁ reaches the second seal line SL ₂ in the gasket 11 is a cross-sectional linear slope portion 17, the metal gasket of the second seal line SL ₂ in 11 third seal line SL ₃ part extending to a fourth sealing line SL ₄ via is a full bead 18 of arcuate cross-sectional shape, the full bead 18 is continuous with the cross-sectional linear flat portion 19 at its inner side.

  As for the piercing holes 14 and 15, as shown in FIG. 3A, the first piercing hole 14 is provided on the outer slope of the full bead 17, and the second piercing hole 15 is provided on the slope 16. The positions and number of the piercing holes 14 and 15 are appropriately adjusted according to the compression characteristics of the metal gasket 11.

Further, the full bead 17 and the other casing 31 form a first sealed gap 42 surrounded by them, and grease G is filled therein. Further, the slope 16, the outer slope of the full bead 17, and the one housing 21 form a second sealed gap 43 surrounded by them, and grease G is filled therewith. When the metal gasket 11 is compressed from the state shown in FIG. 3A to the state shown in FIG. 3B, the volume of each of the sealing gaps 42 and 43 is reduced accordingly, so that the first sealing gap 42 is filled. grease G is outside together with the grease G in the second closed gap 43 of the second seal line SL ₂ via the second piercing hole 15 flows out to the second closed gap 43 via the first piercing hole 14 and the flows out to the first outer sealing line SL _1, the shielding film 41 made of the grease G is formed.

As described above, the seal structure having the above-described configuration is a combination of the metal gasket 11 and the pair of casings 21 and 31 that sandwich the metal gasket 11, and the metal gasket 11 has a casing 21 at its end or a seal bead. , 31 is set to a seal line SL (SL _{1 to} SL ₄ ) around the entire circumference of the gasket, and the main seal function is exhibited in the seal line SL. That is, external dust containing salt water is introduced into the casing. Seal these to prevent entry.

In the seal structure having the above-described configuration, the shielding film 41 made of the grease G is formed on the outside of the seal line SL, particularly on the outside of the first and second seal lines SL ₁ and SL ₂ that are easily exposed to external salt water. The presence of the shielding film 41 made of grease G makes it difficult for external salt water to reach the vicinity of the first and second seal lines SL ₁ and SL ₂ . Accordingly, the external salt water hardly reaches the first and second seal lines SL ₁ and SL ₂ , and therefore corrosion of the casings 21 and 31 due to salt water retention on the seal lines SL ₁ and SL ₂ is less likely to occur. The sealing function by the gasket 11 can be maintained over a long period of time. In addition, since the sealing gaps 42 and 43 are filled with the grease G even after the gasket is compressed, the grease G can protect the third and fourth seal lines SL ₃ and SL ₄ from salt water.

  In addition, since the metal gasket 11 is made of a laminated structure in which the rubber layer 13 is attached to the surface of the metal substrate 12, the rubber layer 13 is well-familiar with the roughness of the surfaces of the casings 21 and 31. To do. Therefore, it is possible to improve the sealing performance of the metal gasket 11 itself.

Further, since the grease G is supplied from the inside to the outside of the seal lines SL ₁ and SL ₂ via the pierce holes 14 and 15 provided in advance in the metal gasket 11, the grease G is automatically supplied to the first and second when the gasket is compressed. It can be supplied to the outside of the seal lines SL ₁ and SL ₂ . Therefore, when assembling the seal structure, the grease G may be applied to the gasket 11 in advance, and there is no need to perform a grease injection operation after assembly. Therefore, it is easy to assemble the seal structure while handling the grease G.

Further, since the pierce holes 14 and 15 are provided in the vicinity of the bolt holes 16 that are the fastening points of the assembly bolts, the grease supply from the inside to the outside of the first and second seal lines SL ₁ and SL ₂ The amount can be set large.

  In the above embodiment, the pair of casings 21 and 31 are made of aluminum, but one or both of them may be made of iron.

  In the above embodiment, the tip of the slope portion 17 is already in contact with one housing 21 in the state of FIG. 2A (the state before compression), but at this stage, the tip of the slope portion 17 is It does not have to be in contact with one housing 21. In this case, the front end of the slope portion 17 comes into contact with one housing 21 as the gasket 11 is compressed by the pair of housings 21 and 31, and the front end of the slope portion 17 is in contact until the contact. The gap between the housings 21 acts as a flow path for the grease G to overflow from the inside of the tip of the slope portion 17 to the outside.

  Further, the seal bead may be a full bead or a half bead.

DESCRIPTION OF SYMBOLS 11 Metal gasket 12 Metal substrate 13 Rubber layer 14,15 Pierce hole 16 Bolt hole 17 Slope part 18 Full bead 19 Plane part 21,31 Case 41 Shielding film 42,43 Sealing gap G Grease

Claims (5)

It is a structure that seals between a pair of housings with a metal gasket having a seal bead,
A shielding film made of grease that suppresses salt water outside the casing from reaching a seal line set by pressing the metal gasket against the casing is formed outside the seal line. Seal structure with metal gasket. The seal structure according to claim 1,
The metal gasket has a laminated structure in which a rubber layer is attached to the surface of a metal substrate. The seal structure according to claim 1 or 2,
The grease is a seal structure using a metal gasket, wherein the grease is supplied from the inside to the outside of the seal line through a pierce hole provided in advance in the metal gasket. The seal structure according to claim 3.
The said piercing hole is provided in the circumference | surroundings of the said metal gasket in the fastening location vicinity of an assembly bolt, The sealing structure by the metal gasket characterized by the above-mentioned. The seal structure according to any one of claims 1 to 4,
The metal gasket sequentially sets first to fourth seal lines from the outer side to the inner side of the housing, and among the first and third seal lines, the metal gasket is pressed against one of the housings. And the second and fourth seal lines are set by pressing the metal gasket against the other casing,
A portion from the first seal line to the second seal line in the metal gasket forms a slope portion having a linear cross section, and the fourth seal from the second seal line through the third seal line in the metal gasket. The part that reaches the seal line has a full bead with an arc cross section,
A first pierced hole is provided in the outer slope of the full bead and a second pierced hole is provided in the slope part;
The first sealed gap surrounded by the full bead and the other casing and the second sealed gap surrounded by the slope portion, the outer slope and the one casing are filled with grease,
The grease filled in the first sealing gap flows out to the second sealing gap through the first piercing hole, and the grease in the second sealing gap passes through the second piercing hole to the second. A seal structure using a metal gasket, which flows out to the outside of the seal line and the outside of the first seal line.

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