JP2008138805A - Seal member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seal member which prevents itself from being pinched between two members and requires a small installation load even when its deformed amount is large. <P>SOLUTION: A first lip part 16 and a second lip part 18 are formed integrally with a thin-wall part 20 connecting these lip parts to each other. The end surface of the first lip part 16 is so formed in a tapered shape 24 or a curved shape 26 that its center part 22 projects. Since the first lip part 16 is flexibly deformed by the thin-wall part 20 during the installation, and the seal member to be installed can be smoothly moved along the tapered shape, the installation load can be reduced. Also, the seal member is surely prevented from being pinched into the gap between the two members by forming the first lip part 16 to have a width larger than that of the second lip part 18. By forming the second lip part 18 in a forked leg shape, the flexibility of the seal member during the installation can be further increased, and the installation load can be further reduced. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a seal member that is mounted and sealed between two members. The two members may rotate or reciprocate with each other such as a piston and cylinder, a shaft member and a bearing member, or may be fixed with each other such as a rod and a support hole member or a flange.

  Conventionally, when statically or dynamically sealing between two members, a seal member such as an O-ring or an X-ring has been often used. The O-ring is an annular body having an O-shaped cross section as shown in FIG. 7, and the X-ring is an annular body having an X-shaped cross section as shown in FIG. 8, both of which are made of an elastic material such as rubber or resin. (For the X ring, see Patent Document 1).

  Usually, one of the two members is provided with a mounting groove for accommodating the seal member. The seal member abuts and is fixed to the bottom surface of the mounting groove provided in one member, and seals between the two members in a liquid-tight or air-tight manner by contacting the surface of the other member.

  When assembling the two members, the sealing member is first disposed in the mounting groove, and then one or both of the two members are moved to a predetermined position to perform the mounting operation. For example, in the case of a rod and a support hole member, the seal member is accommodated in a mounting groove provided in one of the rod or the support hole member, and the rod is inserted into the support hole member and arranged at a predetermined position.

However, when a conventional O-ring is used, there is a problem that a load (hereinafter also referred to as “mounting load”) when moving (inserting) a member to a predetermined position in the mounting operation is large. In order to reduce this mounting load, a lip-shaped seal such as an X ring is used.
JP 2005-36827 A

  In recent years, as the use of plastics for parts has progressed and the processing cost has been reduced, the processing tolerance of the member to which the seal member is attached tends to increase. To cope with this increased processing tolerance, it is necessary to set the crushing amount of the seal member large. However, if the crushing amount of the conventional O-ring or X-ring is set large in order to maintain the sealing performance, the assembly of the member At the time of mounting, there is a problem that the mounting load becomes large and it is difficult to perform the mounting operation, or the sealing member is sandwiched in the gap between the two members at the time of mounting, which adversely affects the sealing performance and life.

  An object of the present invention is to provide a seal member that is easy to perform a mounting operation with a small mounting load even when the amount of crushing is large. And

  Another object of the present invention is to provide a seal member that exhibits good sealing performance without sandwiching the seal member between the members even when the amount of crushing is large.

  In order to achieve the above-mentioned object of the present invention, even when the amount of crushing is excessive, the seal member is caused to be appropriately deformed, and a surface serving as a guide at the time of inserting the shaft is provided to improve the mounting property.

  Specifically, in a seal member that is housed in a mounting groove provided on one of the two members and seals between the two members, a first lip portion that contacts the other member of the two members, and the mounting groove The first lip portion has a second lip portion that is in contact with the bottom surface of the lip portion and a thin portion that connects the first lip portion and the second lip portion. It is formed in such a taper shape or a curved surface shape.

  From the viewpoint of smoothly sliding the mating member in contact with the first lip portion, the taper angle in the cross section of the seal member is preferably 10 to 45 ° with respect to the thickness direction (that is, the width w1 direction in FIG. 3). Most preferred is 22 °. In the case of a curved surface shape, it is preferable to have a single curvature over the entire thickness of the first lip portion in the cross section of the seal member. Moreover, it is good also as a surface which combined several curvature.

  In the present invention, it is preferable to form the first lip portion with a smaller width than the second lip portion from the viewpoint of preventing the two members from being caught in the gap.

  Furthermore, in the present invention, it is preferable that the second lip portion is formed in a bifurcated leg shape from the viewpoint of enhancing flexibility while maintaining stability.

  As the material of the seal member of the present invention, an elastomer used for general packing such as fluorine rubber, NBR, HNBR, silicon rubber, acrylic rubber, thermosetting / thermoplastic resin material, or the like can be used.

Next, the operation of the problem solving means of the present invention will be described.
Since the tip surface of the first lip portion is formed in a taper shape or a curved surface shape so that the center portion protrudes, when assembling to the other member with the seal member accommodated in the mounting groove of one member Since the first lip portion is easily deformed by the thin portion and can be smoothly inserted along the tapered surface or the curved surface, the mounting load can be kept low. When the two members rotate with respect to each other or reciprocate in the axial direction, the sliding resistance is small.

  Further, when the first lip portion is formed smaller than the width of the second lip portion, it is deformed until the side end portion (maximum width portion) of the first lip portion abuts against the inner wall surface of the mounting groove during mounting. It is possible to reliably prevent the gap between the members from being caught, and to prevent the seal member from being reversed, tilted, twisted, and the like.

  Furthermore, when the second lip portion is formed in a bifurcated leg shape, the leg is opened until the leg abuts against the inner wall surface of the mounting groove during mounting, so that the deformation is further facilitated and the mounting load can be further reduced.

  As described above, in the present invention, the first lip portion and the second lip portion are integrally connected by the thin portion, and the tip surface of the first lip portion is tapered or curved so that the center portion protrudes. Due to the formation, it has excellent flexibility, and even when the amount of crushing is large, the mounting load does not become excessive, and the mounting operation becomes easy.

  In addition, since the first lip portion is formed to be smaller than the width of the second lip portion, even when the crushing amount is large, the gap between the members is not caught, and high sealing performance can be maintained.

  Furthermore, the mounting load can be further reduced by forming the second lip portion into a bifurcated leg shape.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a first embodiment of the present invention and shows a cross section of a seal member 10. The seal member 10 is an annular body formed integrally from an outer first lip portion 16, an inner second lip portion 18, and a thin wall portion 20 that connects the first lip 16 and the second lip portion 18. It is. The front end surface of the first lip portion 16 has a tapered shape 24 so that the central portion 22 protrudes. The second lip portion 18 has a leg shape divided into two forks. Between the first lip portion 16 and the second lip portion 18, there is a thin portion 20 having a narrow width (that is, a thin thickness). As shown in FIG. 3, the width w1 of the first lip portion 16 is smaller than the width w2 of the second lip portion.

  FIG. 2 shows a second embodiment of the present invention. The first embodiment of the present invention shown in FIG. 1 is different from the first embodiment in that the front end surface of the first lip portion 16 has a curved shape 26 such that the central portion 22 protrudes, and the second lip portion. 18 is that a projection 28 is provided on the crotch of two legs. The projecting portion 28 functions as a reinforcing material and a stopper when the two legs of the second lip portion 18 are deformed to open in the mounting groove at the time of mounting, reinforces the strength of the crotch portion, restricts deformation, and reduces the mounting groove. To increase the stability within.

  1 and 2, the first lip portion 16 is located outside the annular seal member and the second lip portion 18 is located inside, but the opposite is also possible. It is. That is, the first lip portion 16 may be located inside the annular seal member, and the second lip portion 18 may be located outside. This will be described with reference to FIGS.

  FIG. 4 shows a case where the mounting groove 30 is provided in the inner rod member 50 of the two members to be sealed. The mounting groove 30 accommodates the seal member 10 of the present invention shown in FIG. At the time of mounting, the outer mating member is located at the position of the alternate long and short dash line A. The first lip portion 16 abuts on the outer surface of the outer mating member indicated by the alternate long and short dash line A, and the second lip portion 18 abuts on the bottom surface of the mounting groove 30. In this case, the first lip portion 16 is located outside the annular seal member, and the second lip portion 18 is located inside.

  FIG. 5 shows a case where the mounting groove 40 is provided in the outer member 60 of the two members to be sealed. The mounting member 40 accommodates the seal member 14 of the present invention. At the time of mounting, the inner mating member is located at the position of the alternate long and short dash line A. The first lip portion 16 abuts on the outer surface of the inner mating member indicated by the alternate long and short dash line A, and the second lip portion 18 abuts on the bottom surface of the mounting groove 40. In this case, the first lip portion 16 is positioned inside the annular seal member, and the second lip portion 18 is positioned outside.

  In addition, the sealing member of this invention can also be formed so that a 1st lip part may be located in an upper side (or lower side) and a 2nd lip part may be located in a lower side (or upper side), respectively (for example, in the case of a flange).

Next, mounting of two members to be sealed will be described.
FIG. 3 is an enlarged view showing a state in which the sealing member 10 of the present invention shown in FIG. When the two members to be sealed are mounted, the counterpart member comes to the position indicated by the alternate long and short dash line A. Therefore, the distance from the alternate long and short dash line A to the center portion 22 of the front end surface of the seal member 10 is a crushing allowance.

  In the mounting operation, first, the sealing member 10 of the present invention is arranged in the mounting groove 30 of one member, and is inserted in the axial direction so that the counterpart member is installed at a predetermined position. When the first lip portion 16 abuts against the mating member, the first lip portion 16 is flexibly deformed in the direction to which the load is applied thanks to the presence of the thin portion 20, and can move smoothly along the tapered shape 24. Mounting load becomes lighter. At this time, since the two leg portions of the second lip portion 18 can be flexibly deformed, the mounting load is further reduced. Further, since the width w1 of the first lip portion 16 is smaller than the width w2 of the second lip portion 18, when the first lip portion 16 is deformed in the direction to which a load is applied at the time of mounting, the first lip portion 16 is inserted into the gap between the two members. Is prevented from being caught.

Next, the relationship between the crushing allowance and the mounting load will be described.
FIG. 6 shows the experimental results of measuring the mounting load with different crushing margins, comparing the sealing member of the present invention, the conventional O-ring, and the conventional X-ring. These seal members have a larger mounting load as the crushing cost increases, but it is understood that the degree of increase is the smallest in the seal member of the present invention. Further, in this experiment, when the crushing margin was the maximum, the conventional O-ring and X-ring were caught in the gap between the two members, but the sealing member of the present invention did not. From this experiment, even when the crushing amount is large, the mounting load of the seal member of the present invention is sufficiently smaller than that of the conventional seal member, and does not cause a phenomenon such as pinching, and exhibits excellent sealing performance. I understood.

It is sectional drawing of the sealing member which shows the 1st Embodiment of this invention. It is sectional drawing of the sealing member which shows the 2nd Embodiment of this invention. It is an expanded sectional view showing the state where the seal member of the present invention is arranged in the installation groove. It is sectional drawing which shows the mounting state of the sealing member of this invention which has a 1st lip | rip part outside. It is sectional drawing which shows the mounting state of the sealing member of this invention which has a 1st lip part inside. It is the graph which compared the relationship between crushing allowance and mounting load about the sealing member of this invention, the conventional O-ring, and X ring. It is sectional drawing of the conventional O-ring. It is sectional drawing of the conventional X ring.

Explanation of symbols

10, 12, 14 Seal member 16 1st lip part 18 2nd lip part 20 Thin part (narrow part)
22 Central portion 24 of the front end surface of the first lip portion Tapered shape portion 26 Curved shape portion 28 Projection portions 30 and 40 Mounting groove 100 O-ring 200 X-ring

Claims (3)

  A seal member that is accommodated in a mounting groove provided on one of the two members and seals between the two members, and a first lip portion that contacts the other member of the two members; and a bottom surface of the mounting groove The first lip portion is tapered so that the center portion projects from the abutting second lip portion, and the thin lip portion connecting the first lip portion and the second lip portion. A sealing member formed into a shape or a curved surface.   The seal member according to claim 1, wherein the first lip portion is formed to have a smaller width than the second lip portion. The seal member according to claim 1, wherein the second lip portion is formed in a bifurcated leg shape.