JP2012092893A - Sealing structure of gasket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing structure of a gasket capable of securing an interference which can absorb dimension variation of an opposite member and waviness of the surface and capable of maintaining stable sealing property which suppresses reaction force of the gasket and does not cause deformation on the opposite member.SOLUTION: The sealing structure of gasket has a seal rib on the top part of a hollow seal part and has the hollow seal part which is provided with a fall prevention part on the inner circumferential side on the lower part of the hollow seal part, wherein the seal rib is further formed with an oblique line made by smoothly connecting seal rib top end part formed near the center line of the hollow seal part and a circular arcuate sidewall part on the inner circumferential side and a seal rib connection part which is extended substantially in parallel with the center line from the seal rib top end part and is connected to the hollow seal part, and a second attachment groove part is formed such that the whole of the compressively deformed hollow seal part can be housed in such a state that the first member and the second member are tightly adhered.

Description

  The present invention relates to a gasket sealing structure used for, for example, a resin container or a cover, in which a gasket is interposed between two members to seal both members in an airtight and watertight manner.

  In recent years, a mounting member such as a housing or a case in which a gasket is mounted has been made lighter by changing the material from metal to resin.

  However, when the mounting member is made of resin in this way, variations in gasket height and sag, or dimensional variations in the resin member (for example, groove tolerance), surface waviness, creep deformation, etc. Since it is large, there is a case where a substantial tightening margin is reduced and there is no room for the tightening margin. For this reason, the height dimension of the gasket must be formed large in order to ensure the necessary tightening allowance over the entire circumference.

  However, for example, in the conventional gasket seal structure 100 as shown in FIG. 2, since the reaction force of the gasket 60 attached to the attachment member 62 is high, the resin cover 64, which is the counterpart member, is deformed to cause a circumferential direction. There may be gaps. Therefore, if the resin cover 64 is reinforced with a metal retainer in order to suppress deformation, it becomes an expensive specification. Further, the set crushing allowance D becomes too large at the maximum value, and there arises a disadvantage that the gasket 60 tends to fall between the mounting members. On the other hand, if the rubber material of the gasket is made to have a low hardness specification in order to keep the reaction force generated at the time of installation, it will be even easier to fall down, so the gasket's posture stability and further low load / high tightening allowance can be achieved. A seal structure is desired.

  As measures for improvement, Patent Document 1 discloses a gasket having a lip-shaped seal formed at the tip, and Patent Document 2 discloses a gasket in which a part of the gasket is hollow.

  As shown in FIG. 3, the gasket 70 disclosed in Patent Document 1 includes a main body portion 74 that is inserted into the mounting groove 71 of one member 72, and a protruding portion that protrudes from the main body portion 74 toward the other member 73. 76, and the protrusion 76 is provided so as to extend in a direction intersecting the direction in which the two members are in close contact with each other. For this reason, when the other member 73 is in close contact, the protrusion 76 falls down only in the direction in which the inclination angle α increases. That is, the deformation direction in the mounting groove 71 when the two members are in close contact with each other is constant. As a result, a decrease in sealing performance due to a change in the direction of falling depending on the circumferential position is suppressed.

  Further, the gasket 80 disclosed in Patent Document 2 is made of an elastic body, and is mounted in a mounting groove 82 of a resin mounted member 81 as shown in FIG. The gasket 80 has an elliptical shape in which the cross-sectional shape along the direction in which the gasket 80 is compressed (the vertical direction in FIG. 4A and the Y arrow direction) is long in the compression direction. It is an endless annular body continuous in the circumferential direction. And the gasket 80 has the hollow part 83 of the circular cross section which continues in the circumferential direction in the center of an oval cross section.

  When the mating member 84 of the mounted member 81 is pressed against the gasket 80 and a tightening load is applied, the gasket 80 is compressed in the direction in which the hollow portion 83 is crushed, as shown in FIG. The major axis length of the circular cross section is shortened. At this time, a reaction force for the compression is generated inside the gasket 80, but this reaction force is reduced by the amount of the hollow portion 83 provided. For this reason, the creep deformation of the resin mounted member 81 and the like due to the reaction force of the gasket 80 compressed between the mounted member 81 and the mating member 84 can be suppressed. Further, since restoring force is obtained by the air enclosed in the hollow portion 83, the sag of the gasket 80 can be suppressed.

JP 2009-257459 A JP 2002-349711 A

  However, in the gasket 70 disclosed in Patent Document 1, the main body portion 74 that generates a reaction force by being compressed is embedded in the mounting groove 71, and only the protruding portion 76 protrudes from the mounting groove 71 to the other member 73. It comes to come in pressure contact. Therefore, it is not possible to secure a tightening allowance having a margin with respect to the dimensional variation of the other member 73 and the gasket 70.

  Further, in the gasket 80 disclosed in Patent Document 2, more than half of the portion in the compression direction is held in the mounting groove 82 in a state where the portion is disposed in the mounting groove 82. In the unloaded state where the tightening load from the mating member 84 of the mounted member 81 does not act on the gasket 80, most of the hollow portion 83 exists in the mounting groove 82, and the substantially solid portion Only exists outside the mounting groove 82.

  For this reason, the solidity of the gasket 80 existing outside the mounting groove 82 in a tightening load application state due to, for example, variation in dimensions (for example, groove tolerance) of the resin mounted member 81 and the mating member 84 and surface waviness. It is conceivable that the portion is deformed to be twisted and distorted, or tilted and tilted. If it does so, the compression degree of the solid part of the gasket 80 compressed between the attachment groove | channel 82 and the counterpart member 84 will reduce, a seal surface pressure will fall and it cannot ensure stable sealing performance.

  The present invention has been made in view of the above circumstances, and secures a tightening allowance capable of absorbing the dimensional variation of the mating member and surface waviness, and suppresses the reaction force of the gasket to cause deformation of the mating member. It is an object of the present invention to provide a gasket sealing structure that can maintain an inexpensive and stable sealing performance.

  In order to achieve the above object, a gasket sealing structure according to the present invention is held in an annular mounting groove formed in a first member, and a lower surface of a second member which is a counterpart member of the first member is a first member. The gasket is sandwiched and sealed between the two members by being pressed against each other, and the mounting groove has a first mounting groove and a second mounting groove wider than the first mounting groove. The gasket is formed integrally with the solid seal portion disposed in the first mounting groove portion and held in the first mounting groove portion, and the upper portion of the solid seal portion, and the solid seal portion is formed in the first mounting groove portion. A hollow seal portion that is located outside the first mounting groove when in a held state and is formed of an arc-shaped side wall portion that divides a sealed hollow portion that is continuous in the circumferential direction, and the hollow seal portion has a seal rib at the top thereof , Adjacent to the solid seal part at the bottom The seal rib is provided with a tilt prevention portion at a position on the inner peripheral side, and the seal rib includes a hypotenuse that smoothly connects the tip end portion of the seal rib formed near the center line of the hollow seal portion and the arc-shaped side wall portion on the inner peripheral side, and the tip end of the seal rib Formed from a seal rib connecting portion extending substantially parallel to the center line from the portion and connected to the hollow seal portion, and the second mounting groove portion is formed on the arc-shaped side wall portion with the seal rib tip contacting the lower surface of the second member. In a state where a part is accommodated and the first member and the second member are in close contact with each other, the entire hollow seal portion that is compressed and deformed is formed so as to be accommodated.

  In this gasket sealing structure, the gasket is configured such that the hollow seal portion is positioned outside the first mounting groove when the solid sealing portion is held in the first mounting groove. The solid seal portion is disposed in the first mounting groove and is held in the first mounting groove. Therefore, only the solid seal portion of the gasket is held in the first mounting groove, and the gasket can be securely held in the mounting groove, and the posture stability of the gasket can be improved. .

  Since the hollow seal portion has a sealing rib and a sealed hollow portion that is continuous in the circumferential direction, when a tightening load is applied to the gasket, the solid seal portion is mainly compressed without deformation. The part is compressed and deformed. For this reason, in the gasket of this invention, it becomes a low repulsive force by presence of a hollow seal part, and can suppress the creep deformation of the 2nd member which is a counterpart member favorably.

  The hollow seal portion includes a hypotenuse that smoothly connects the tip end portion of the seal rib formed in the vicinity of the center line of the hollow seal portion and the arcuate side wall portion on the inner peripheral side, and extends from the tip end portion of the seal rib substantially parallel to the center line. Since the seal rib is formed from the seal rib connecting portion that is connected to the arcuate side wall portion, when a tightening load is applied to the gasket, the deformation direction of the hollow seal portion is constant, and the direction in which the gasket falls depending on the circumferential position is determined. There is no change and the sealing performance is stable. Even when the amount of compression is reduced due to variations or deformation of each member, the fall prevention part formed at the lower part of the hollow seal part supports the arcuate side wall part on the inner peripheral side, so that the seal rib is It is possible to effectively follow and secure a good sealing property.

  As described above, the seal structure of the gasket of the present invention including the hollow seal portion projecting mainly from the first mounting groove portion and having the hollow seal portion having a small reaction force after compressive deformation is deformed by being applied with the tightening load. In this case, it is possible to set a larger allowance than in the conventional case.

  In a preferred aspect of the gasket sealing structure of the present invention, the position of the seal rib connecting portion in the cross section perpendicular to the circumferential direction is 0.15 w on the inner peripheral side from the center line when the width dimension of the sealed hollow portion is w. To the position on the outer peripheral side of 0.25w from the center line.

  By forming the seal rib in this way, when a tightening load is applied to the gasket, the seal rib can be tilted smoothly and can be buried while compressing and deforming the hollow seal portion, further ensuring sealing performance. Can be.

  Therefore, according to the gasket sealing structure of the present invention, the mating member may have a high tightening allowance for absorbing the dimensional variation of the mating member and the surface waviness, and the mating member may be deformed by suppressing the reaction force of the gasket. It is possible to provide a gasket sealing structure that can ensure good sealing performance over a long period of time. Further, according to this gasket sealing structure, a metal retainer for suppressing deformation of the mating member is not required, and the gasket sealing structure is inexpensive.

It is sectional drawing which shows the state before the fastening load provision of the seal structure which concerns on embodiment. It is sectional drawing which shows the state before the fastening load provision of the conventional gasket. It is sectional drawing which shows the state before the fastening load provision of another conventional gasket. (A) is sectional drawing which shows the state before a fastening load provision, (b) is sectional drawing which shows the state after a fastening load provision regarding another conventional gasket.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG.

  The gasket seal structure 1 of the present embodiment is a gasket seal structure that is attached to a case for storing a battery pack such as a hybrid vehicle or an electric vehicle, and prevents moisture from entering the battery pack. The battery pack storage case includes an upper case (second member) 20 formed from a resin material such as PP (polypropylene) + GF (glass fiber) or PA66 (polyamide 66) into a substantially rectangular box shape by injection molding or the like. Lower case (first member) 10. An annular mounting groove 11 is recessed in the outer peripheral edge of the lower case 10. The mounting groove 11 has a two-stage configuration, a first mounting groove portion 12 is formed in the lower stage, and a second mounting groove section 13 that is an accommodating portion is formed in the upper stage.

  A gasket 30 is disposed between the lower surface of the upper case 20 and the mounting groove 11 so as to be sandwiched between the bottom surface 12 a of the first mounting groove portion 12 and the lower surface of the upper case 20. FIG. 1 is a partial cross-sectional view showing a state in which a gasket 30 according to the present embodiment is disposed between the upper case 20 and the mounting groove 11 facing each other, and is a cross section orthogonal to the circumferential direction extending in an annular shape. The state before the tightening load is not applied to the gasket 30 is shown.

  The gasket 30 is integrally formed with a solid seal portion 32 that is formed solidly and a hollow seal portion 36 that includes an upper seal rib 34 at the top and has a sealed hollow portion 38 that is continuous in the circumferential direction. An annular rubber-like elastic body. Here, as the rubber-like elastic body constituting the gasket 30, an elastic material such as a thermoplastic elastomer, for example, EPDM (ethylene propylene rubber), ACM (acrylic rubber), NBR (nitrile rubber), FVMQ (fluorosilicon), or the like is used. Although it can mention, if it can ensure the sealing performance as a gasket, it will not specifically limit, A conventional thing can be used. Further, the gasket 30 has a cross-sectional shape orthogonal to the circumferential direction extending in an annular shape, except for the upper seal rib 34 and the fall prevention portion 33 with respect to the center line L extending in the compression direction (vertical direction in FIG. 1) in which the gasket is compressed. And has a symmetrical shape.

  The solid seal portion 32 of the gasket 30 has a substantially rectangular cross section and is entirely held in the first mounting groove portion 12 in a press-fitted state. In FIG. 1, the protrusion part which protrudes toward the inside of the 1st attachment groove part 12 from the outer side surface of the solid seal part 32 and the side wall surface 12c of the 1st attachment groove part 12 is provided facing the appropriate position of the circumferential direction. The solid seal portion 32 is compressed and sandwiched between these projecting portions. If the solid seal portion 32 is compressed and sandwiched between the protruding portions of the first mounting groove portion 12 in this way, the posture stability of the solid seal portion 32 with respect to the mounting groove 11 can be enhanced, and the gasket 30 can be stabilized. Can be held in the posture. Further, the solid seal portion 32 is provided with a lower seal rib 37 in contact with the bottom surface 12a of the first mounting groove portion 12 at the bottom thereof, thereby further ensuring the sealing performance in the mounting groove 11. In addition, there may be no protrusion part which protrudes from the side wall surface 12c, and the process of the 1st attachment groove part 12 becomes easy in this case.

  The hollow seal portion 36 of the gasket 30 is formed integrally with the solid seal portion 32 described above, and is formed in a substantially circular cross section together with a hermetically sealed hollow portion 38 that is continuous in the circumferential direction. When the portion is held in the first mounting groove 12, the entire portion is located outside the first mounting groove 12. Further, at a position below the hollow seal portion 36 and adjacent to the solid seal portion 32, a fall prevention portion 33 that abuts against the bottom surface 13a of the second attachment groove portion 13 is provided. It is more certain.

  Further, in the gasket 30 of the present embodiment, the width w2 of the hollow seal portion 36 is larger than the width w1 of the solid seal portion 32 in a cross section orthogonal to the circumferential direction in which the gasket 30 extends in an annular shape. . The hollow seal portion 36 has an arc-shaped side wall portion 361 having a substantially uniform thickness and extending in an arc shape, and the arc-shaped side wall portion 361 defines a sealed hollow portion 38. The sealed hollow portion 38 has a linear portion formed downward from the upper end portion of the semicircular arc shape, and has a tapered shape that tapers downward from the lower end of the linear portion. For this reason, the thickness of the lower hollow seal portion 362 corresponding to the tapered shape of the taper is thicker than the general portion of the arc-shaped side wall portion 361. On the inner peripheral side of the lower end portion of the hollow seal portion 36, a fall prevention portion 33 is formed at a portion adjacent to the solid seal portion 32, so that the sealing performance in the mounting groove 11 is further ensured. Further, an upper seal rib 34 is formed in the vicinity of the top of the hollow seal portion 36, and the upper seal rib 34 has a shape in which a seal rib front end portion 341 is formed in the vicinity of the center line L, and a circle on the inner circumferential side from the seal rib front end portion 341. The arcuate side wall portion 361 has a triangular rib shape with a smooth hypotenuse.

  In the gasket seal structure 1 of the present embodiment configured as described above, the upper case 20 is attached to the lower case 10 so that the upper seal rib 34 is folded, so that the hollow seal portion 36 and the sealed hollow portion are When the upper case 20 is compressed in the direction to be crushed together with the lower case 10 and the upper case 20 is in close contact with the lower case 10, the hollow seal portion 36 is accommodated in the second mounting groove portion 13. Since the second mounting groove portion 13 has a groove width at which the deformed arc-shaped side wall portion 361 contacts the side wall surface 13c of the second mounting groove portion 13, the hollow seal portion 36 during applying the tightening load is the second mounting groove portion. It can be compressed and deformed without being restricted by the 13 side wall surfaces 13c. For this reason, in this gasket 30, due to the presence of the sealed hollow portion 38 of the hollow seal portion 36, a low repulsion force is obtained even in a high compression portion where the amount of compression is large, and it is possible to satisfactorily suppress creep deformation of the upper case 20 which is the counterpart member. it can. The second mounting groove portion 13 is not necessarily formed so that the deformed arc-shaped side wall portion 361 contacts the side wall surface 13c of the second mounting groove portion 13; For example, the second mounting groove portion 13 having a wider groove width may be used.

  The hollow seal portion 36 has an inclined side from the inner peripheral side to the outer peripheral side of the annular gasket 30, and a triangular rib-shaped upper seal rib 34 having a seal rib tip 341 in the vicinity of the center line L of the hollow seal portion 36. It has. In addition, at a position below the hollow seal portion 36 and adjacent to the solid seal portion 32, a fall prevention portion 33 that comes into contact with the bottom surface 13 a of the second mounting groove portion 13 is provided. The upper seal rib 34 has a seal rib tip 341 formed in the vicinity of the center line L of the hollow seal portion 36 in contact with the lower surface of the upper case 20 even in a low compression portion where the compression amount of the hollow seal portion 36 is small. Good sealability can be maintained following changes in the amount of compression in the circumferential direction due to dimensional variations and the like. Further, when the upper seal rib 34 is compressed from the lower surface of the upper case 20, the upper seal rib 34 itself extends from the seal rib tip 341 along the center line L and is connected to the top of the arcuate side wall 361. The entire hollow seal portion 36 is compressed while the upper seal rib 34 tilts from the inner peripheral side toward the outer peripheral side while the portion 342 sinks into the hollow seal portion 36. In this series of deformations, the fall prevention portion 33 is in contact with and supported by the bottom surface 13a of the second mounting groove portion 13 so that the posture of the entire hollow seal portion 36 is stabilized and does not tilt toward the inner peripheral side.

  The upper seal rib 34 tilts uniformly from the inner circumference side to the outer circumference side by cooperating with the oblique side from the inner circumference side toward the outer circumference side and the upper seal rib connecting portion 342. Further, due to the cooperation of the upper seal rib 34 and the fall prevention portion 33, the entire hollow seal portion is also tilted uniformly from the inner peripheral side to the outer peripheral side on the entire circumference. In this way, the sealing performance is stabilized over the entire circumference without changing the direction of falling. The tilt deformation of the upper seal rib 34 is caused by the slant side smoothly connecting from the seal rib tip 341 to the arcuate side wall portion 361 on the inner peripheral side of the hollow seal portion 36 and the upper seal rib connecting portion 342 indenting the top of the hollow seal portion 34. This is due to the triangular rib shape that deforms. Therefore, the position of the upper seal rib connecting portion 342 is 0.15 × w3 from the center line L to 0.25 × w3 from the center line L when the width dimension of the sealed hollow portion 38 is w3. A range up to the position on the outer peripheral side is preferable. More preferably, it is a range from the position of the center line L to the position of 0.2 × w3 outer peripheral side from the center line L. If the position of the upper seal rib connecting portion 342 is within this range, the top portion of the hollow seal portion 34 during compression can be deformed with a low load, and the upper seal rib 34 can be smoothly tilted to maintain good sealing performance. Can do.

  In the gasket seal structure 1 according to the present embodiment configured as described above, the tightening allowance C applies a tightening load to the gasket 30 from the state in which the seal rib tip 341 of the upper seal rib 34 is in contact with the lower surface of the upper case 20. The compression amount of the gasket 30 until the upper case 20 is in close contact with the lower case 10. Therefore, by appropriately adjusting the dimension A of the hollow seal portion 36 and the depth B of the second mounting groove portion 13, the dimensional variation of the lower case 10 and the upper case 20, the swell of the surface, the dimensional variation of the gasket 30, etc. What is necessary is just to set the fastening allowance C with the margin which can be absorbed.

  In this embodiment, it is the hollow seal portion 36 that mainly protrudes from the first mounting groove portion 12 to be deformed by applying a tightening load. Even when the upper seal rib 34 starts to be compressed, the hollow seal portion 36 is deformed. It depends. Even if the tightening allowance C is set to a larger value than before, the reaction force after the compression deformation of the hollow seal portion 36 is small. For example, in the conventional seal structure 100 (FIG. 2), when the compression allowance is applied to the gasket 60 with the fastening allowance D being 1.5 mm, the reaction force is 213 N / 100 mm. In contrast, when a compression load was applied to the gasket 30 of the present embodiment with a tightening margin C of 6.2 mm, the reaction force was 68 N / 100 mm.

  The gasket sealing structure of the present invention can be suitably used for a resin-made large case that houses a battery pack that is a power supply device of a hybrid vehicle or an electric vehicle.

1 Gasket seal structure 10 Lower case (first member)
DESCRIPTION OF SYMBOLS 11 Mounting groove 12 1st mounting groove part 12a Bottom surface of 1st mounting groove part 12c Side wall surface of 1st mounting groove part 13 2nd mounting groove part (accommodating part)
13a Bottom surface of second mounting groove 13c Side wall surface of second mounting groove 20 Upper case (second member)
30 Gasket 32 Solid seal portion 33 Fall prevention portion 34 Upper seal rib 341 Seal rib tip portion 342 Upper seal rib connecting portion 36 Hollow seal portion 361 Arc-shaped side wall portion 362 Lower hollow seal portion 37 Lower seal portion 38 Sealed hollow portion 60 Gasket 62 Mounting member 64 Resin cover 70 Gasket 71 Mounting groove 72 One member 73 Other member 74 Main body portion 76 Projection portion 80 Gasket 81 Mounted member 82 Mounting groove 83 Hollow portion 84 Counterpart member 100 Conventional gasket seal structure L Center line w1 Solid seal width w2 Hollow seal width w3 Sealed hollow width

Claims (2)

A gasket that is held in an annular mounting groove formed in the first member and is sandwiched and sealed between the two members by pressing the lower surface of the second member that is the mating member of the first member against the first member; And
The mounting groove portion has a first mounting groove portion and a second mounting groove portion wider than the first mounting groove portion formed in a step shape.
The gasket is formed integrally with a solid seal portion disposed in the first mounting groove portion and held by the first mounting groove portion, and an upper portion of the solid seal portion. A hollow seal portion comprising an arcuate side wall portion that is positioned outside the first attachment groove portion and defines a continuous hollow portion in the circumferential direction when held in the one attachment groove portion; and the hollow seal portion Comprises a seal rib at the top and a fall prevention part at a position on the inner peripheral side adjacent to the solid seal part at the bottom,
The seal rib includes a hypotenuse that smoothly connects the tip end portion of the seal rib formed near the center line of the hollow seal portion and the arcuate side wall portion on the inner peripheral side, and substantially parallel to the center line from the tip end portion of the seal rib. Formed from a seal rib coupling portion extending and coupled to the arcuate side wall portion;
The second mounting groove portion accommodates a part of the arc-shaped side wall portion in a state where the tip end portion of the seal rib is in contact with the lower surface of the second member, and in a state where the first member and the second member are in close contact with each other. A gasket sealing structure characterized by being formed so as to be able to accommodate the entire hollow seal portion that has been compressed and deformed.   In a cross section perpendicular to the circumferential direction, the position of the seal rib connecting portion is 0.15 × w from the center line on the inner peripheral side when the width dimension of the sealed hollow portion is w, and is 0. The gasket seal structure according to claim 1, wherein the gasket seal structure is formed in a range up to a position on the outer peripheral side of 25 × w.

Images