JP4933225B2 - Lip seal - Google Patents

Description

  The present invention relates to a structure of a lip seal.

It is known to prevent leakage of oil or the like by interposing a lip seal between two members facing each other. Patent Document 1 discloses that a groove is provided in one member between the two members, and a lip seal is fitted in the groove before the two members are brought into close contact with each other.
JP 2003-329140 A

  However, when the outer diameter of the lip seal is set to be slightly larger than the inner diameter of the groove so as to eliminate the gap between the lip seal and the groove, after the lip seal is fitted into the groove of one member, If even a slight external force is applied to the lip seal before the members are brought into close contact with each other, the contact portion between the outer peripheral portion of the lip seal and the inner wall of the groove may slip, and the lip seal may be lifted off the groove.

  An object of the present invention is to prevent lifting when a lip seal is fitted in a groove while maintaining sealing performance.

The present invention is attached to an annular recess provided in one of two members facing each other, and an outer peripheral side surface along the thickness direction is pressed against an inner wall side surface of the annular recess, and one member and the other 2 between the members in the sealing member partially close the seal line cormorants ring shape of the side surfaces along a direction intersecting the thickness direction, contact Keru both sides on the outer peripheral edge portion of the seal member when the members are joined An annular convex portion protruding in the thickness direction is formed so as to be continuous from the surface to the outer peripheral side surface, and the outer peripheral side surface is configured as a surface substantially parallel to the inner wall side surface of the annular concave portion.

  According to the present invention, since the annular convex portion is provided at the outer peripheral end portion of the seal member, the contact area between the seal member and the inner wall of the concave portion to which the seal member is attached is increased, and the seating property of the seal member is increased. And the seal member can be prevented from floating from the recess when an external force is applied.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1A and 1B are configuration diagrams showing the structure of a lip seal in a conventional example. FIG. 1A is a plan view, and FIG. 2A and 2B are configuration diagrams showing the structure of the lip seal in the present embodiment, in which FIG. 2A is a plan view and FIG.

  The lip seal 1 (seal member) is a ring-shaped seal member, and a seal lip portion 2 having a cross-sectional shape is formed on the inner peripheral portion. The lip seal 1 of the present embodiment is different from the conventional example in that an annular convex portion 3 extending in the thickness direction perpendicular to the radial direction of the lip seal 1 is provided from the vicinity of the outer peripheral side end portion shown by hatching in FIG. . The annular protrusions 3 are provided on both surfaces of the lip seal 1, and the length in the thickness direction of the outer peripheral side surface of the lip seal 1 is increased by the height of the protrusions 3 on both surfaces. However, the width in the thickness direction of the convex portion 3 of the lip seal 1 is set to be smaller than the width in the thickness direction of the seal lip portion 2 so as not to impair the sealing performance.

  Next, the operation of the lip seal 1 in this embodiment will be described with reference to FIGS. 3A and 3B are schematic views showing the assembly of the lip seal 1 in the conventional example. FIG. 3A shows a state after the assembly, and FIG. 3B shows a state when an external force is applied to the lip seal 1. FIG. 4 is an enlarged view of a region C in FIG. 5A and 5B are schematic views showing the assembly of the lip seal 1 in the present embodiment, where FIG. 5A shows a state after the assembly, and FIG. 5B shows a state when an external force is applied to the lip seal 1. FIG. 6 is an enlarged view of region D in FIG.

  Here, in FIG. 3 to FIG. 6, the transmission case 4 is a joint between the transmission case 4 (one member) and the control valve body 5 (the other member) and connects the respective oil passages 6. The case where the concave portion 7 is formed in the concave portion 7 and the lip seal 1 is fitted into the concave portion 7 will be described.

  First, the problems of the conventional example will be described with reference to FIGS. The lip seal 1 is fitted into the recess 7 provided in the transmission case 4, but since the outer diameter of the lip seal 1 is set to be slightly larger than the inner diameter of the recess 7, the recess 7 is in a state where the lip seal 1 is contracted. It will be inserted into.

  As a result, a predetermined urging force always acts on the inner wall 9 of the recess 7 from the outer peripheral portion 8 of the lip seal 1, so that when an external force is applied to a part of the lip seal 1, The lip seal 1 may be lifted against the frictional force between the outer peripheral portion 8 of the lip seal 1 and the inner wall 9 of the concave portion 7, and the lip seal 1 may come off the concave portion 7.

  Next, the operation of the lip seal 1 in this embodiment will be described with reference to FIGS. In the present embodiment, an annular convex portion 3 extending in the thickness direction of the lip seal 1 from the vicinity of the outer peripheral side end portion of the lip seal 1 is provided, and the inner wall surface of the concave portion 7 extends from the outer peripheral side surface of the lip seal 1 to the side surface of the convex portion 3. Therefore, the contact area between the outer peripheral portion 8 of the lip seal 1 and the inner wall 9 of the concave portion 7 is expanded as compared with the conventional case. The thickness direction of the lip seal 1 is the thickness in the direction perpendicular to the radial direction of the lip seal 1, that is, the thickness of the lip seal 1 in the central axis direction.

  Here, the frictional force between the outer peripheral portion 8 of the lip seal 1 and the inner wall 9 of the recess 7 is the contact area between the outer peripheral portion 8 of the lip seal 1 and the inner wall 9 of the recess 7, that is, the outer periphery of the lip seal 1. Since the width in the thickness direction of the contact portion between the portion 8 and the inner wall 9 of the concave portion 7 is β larger than α in the conventional example, the outer peripheral portion 8 of the lip seal 1 and the concave portion 7 are reduced. The frictional force between the inner wall 9 and the inner wall 9 increases as compared with the conventional example.

  Thereby, even if an external force is applied to a part of the lip seal 1, the side opposite to the center of the lip seal 1 is only slightly lifted, and the lip seal 1 can be prevented from coming off from the recess 7.

  Further, the seal lip portion 2 is formed in a C shape so that one side is in close contact with the control valve body 5 and the other side is in close contact with the transmission case 4, and the seal lip portion 2 is formed between the transmission case 4 and the control valve body 5. When the oil pressure of the oil flowing through the seal lip 2 is applied to the seal lip 2, the seal lip 2 that is in close contact with the control valve body 5 and the seal lip 2 that is in close contact with the transmission case 4 are intimately closely contacted with each other. Secured.

  As described above, in the present embodiment, since the annular convex portion 3 is provided at the outer peripheral end portion of the lip seal 1, the contact area between the lip seal 1 and the inner wall 9 of the concave portion 7 to which the lip seal 1 is attached is increased. The seating property of the lip seal 1 is improved and the lip seal 1 can be prevented from being lifted from the recess 7 when an external force is applied. (Corresponding to claim 1)

  Moreover, since it is comprised as a surface parallel to the inner wall surface 9 of the recessed part 7 from the outer peripheral side surface of the lip seal 1 to the side surface of the convex part 3, the frictional force produced between the lip seal 1 and the inner wall 9 of the recessed part 7 is produced. It becomes large and it can prevent more reliably that the lip seal 1 floats from the recessed part 7. FIG. (Corresponding to claim 2)

  Further, since the lip seal 1 has a C-shaped seal lip portion 2, when hydraulic pressure is applied to the inside of the lip seal 1, the seal lip portion 2 comes into closer contact with the control valve body 5 and the transmission case 4. The sealing performance of the seal 1 can be sufficiently secured. (Corresponding to claim 3)

  Further, since the width in the thickness direction of the convex portion 3 of the lip seal 1 is set to be smaller than the width in the thickness direction of the seal lip portion 2, the convex portion is formed when the control valve body 5 and the transmission case 4 are joined. Since the seal lip 2 is stronger than the control valve body 5 and the transmission case 4 than 3, it is possible to prevent the sealing performance from being impaired. (Corresponding to claim 4)

  Further, since the width in the thickness direction of the lip seal 1 is relatively small between the convex portion 3 and the seal lip portion 2, the convex portion 3 is deformed when the control valve body 5 and the transmission case 4 are joined. Therefore, it is possible to prevent the convex portion 3 from being sandwiched between the control valve body 5 and the transmission case 4.

  The present invention is not limited to the embodiment described above, and various modifications and changes can be made within the scope of the technical idea.

  For example, in the present embodiment, the case where the lip seal 1 is provided at the joint between the transmission case 4 and the control valve body 5 has been described. However, the present invention is not limited to this, and is appropriately used between two members that require sealing. be able to.

It is a block diagram of the lip seal in a prior art example. It is a block diagram of the lip seal in this embodiment. It is a schematic diagram which shows the assembly | attachment of the lip seal in a prior art example. FIG. 4 is an enlarged view of a region C in FIG. 3. It is a schematic diagram which shows the assembly | attachment of the lip seal in this embodiment. It is an enlarged view of the area | region D of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lip seal 2 Seal lip part 3 Convex part 4 Transmission case 5 Control valve body 6 Oil path 7 Concave part 8 Outer part of a lip seal 9 Inner wall of a concave part

Claims (3)

Of the two members facing each other, an annular recess provided in one member is mounted, and an outer peripheral side surface along the thickness direction is pressed against an inner wall side surface of the annular recess, and the one member and the other member are There in the sealing member partially close the seal line cormorants ring shape of the side surfaces along a direction intersecting the thickness direction between the two members when joined,
Annular convex portion that protrudes in the thickness direction as you Keru from the side surfaces to the outer peripheral end portion continuous with the outer peripheral surface of the front Symbol seal member is formed,
The seal member, wherein the outer peripheral side surface is configured as a surface substantially parallel to the inner wall side surface of the annular recess .   The seal member has two seal lip portions that are separated from each other in the thickness direction of the seal member toward the inside of the seal member at an inner peripheral end portion of the seal member, and one seal lip portion is the one of the one seal lip portion. The seal member according to claim 1, wherein the seal member is in close contact with the other member, and the other seal lip portion is in close contact with the other member.   The seal member according to claim 2, wherein a width in the thickness direction of the two seal lip portions of the seal member is larger than a width in the thickness direction of the convex portion.

Images