Sealing device

Abstract

To provide a sealing device which can maintain a sealing state when a counterpart component is eccentrically placed.SOLUTION: A sealing device 100 is disposed in a gap 250 formed by an inner peripheral surface of an insertion hole formed at a first member, an outer peripheral surface of a second member inserted into the insertion hole, and a third member 230 located at one side of the second member in an axial direction of the insertion hole and seals the gap 250. The sealing device 100 includes: an annular body part 10 having a contact part 11 which contacts with the inner peripheral surface of the first member; a seal lip part 30 which extends from the body part 10 to the radial inner side and contacts with the outer peripheral surface of the second member; and a side lip part 50 which extends in the axial direction from the body part 10 and contacts with the third member 230. The side lip part 50 has: a first lip part 51; and a second lip part 52 which is branched from the first lip part 51 and located at the radial outer side relative to the first lip part 51.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a sealing device. [Background technology]

[0002] Patent Document 1 describes a sealing device used as a plug tube seal, etc. The sealing device in this document has an annular main body, a seal lip portion extending radially inward from the main body, and a side lip portion extending axially from the main body. Of these, the main body abuts against the inner peripheral surface of a first member (the outer member in the same document: for example, a head cover of an engine). The seal lip abuts against the outer peripheral surface of a second member (the inner member in the same document: for example, a plug tube). The side lip abuts against a third member (the mating member in the same document: for example, the coil body of a plug top coil of an ignition device). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-92271 Summary of the Invention [Problem to be solved by the invention]

[0004] However, according to the investigations of the present inventors, there is still room for improvement in the sealing device of Patent Document 1 in terms of maintaining the sealing state by the side lip portion even when the third member is eccentric.

[0005] The present invention has been made in consideration of the above problems, and provides a sealing device that is capable of maintaining a sealed state by a side lip portion even when the third member is eccentric. [Means for solving the problem]

[0006] According to the present invention, there is provided a sealing device that is disposed in a gap between an inner circumferential surface of an insertion hole formed in a first member, an outer circumferential surface of a second member inserted into the insertion hole, and a third member located on one side of the second member in an axial direction of the insertion hole to seal the gap, comprising: an annular main body portion having an abutment portion that abuts against the inner circumferential surface of the first member; a seal lip portion extending radially inward from the main body portion and contacting the outer circumferential surface of the second member; A side lip portion extending from the main body portion in the axial direction and abutting against the third member; Equipped with There is provided a sealing device in which the side lip portion has a first lip portion and a second lip portion branching off from the first lip portion and positioned radially outward relative to the first lip portion. Effect of the Invention

[0007] According to the present invention, it is possible to maintain the sealing state by the side lip portion even when the third member is eccentric. [Brief description of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view taken along a central axis of a sealing device according to an embodiment. FIG. [Diagram 2] 1 is a cross-sectional view showing an example of a mounting structure for a sealing device according to an embodiment. [Diagram 3] FIG. 3 is a partially enlarged view of FIG. [Figure 4] FIG. 13 is a diagram showing a state in which eccentricity occurs. [Diagram 5] FIG. 11 is a partially enlarged cross-sectional view of a sealing device according to a comparative example. [Figure 6] 13 is a diagram showing a state in which a sealing device according to a comparative example is eccentric; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In all the drawings, the same components are denoted by the same reference numerals, and the description thereof will be omitted as appropriate. 2 to 4 show cross sections along the central axis AX1 of the sealing device 100 according to the embodiment, similar to Fig. 1. Fig. 4 shows the same range as Fig. 3. Figures 5 and 6 show cross sections along the central axis of a sealing device 1000 relating to a comparative embodiment, with Figure 5 showing a range similar to that of Figure 3 and Figure 6 showing a range similar to that of Figure 4.

[0010] As shown in Figures 1 to 4, the sealing device 100 of this embodiment is a sealing device 100 that is disposed in a gap 250 between an inner surface 211a of an insertion hole 211 formed in a first member 210 (Figure 2), an outer surface 220a of a second member 220 (Figure 2) inserted into the insertion hole 211, and a third member 230 located on one side (left side in Figure 2) of the second member 220 in the axial direction AX2 of the insertion hole 211, and seals the gap 250. The sealing device 100 comprises an annular main body portion 10 having an abutment portion 11 that abuts against an inner surface 211a of a first member 210, a seal lip portion 30 that extends radially inward from the main body portion 10 and abuts against an outer peripheral surface 220a of a second member 220, and a side lip portion 50 that extends from the main body portion 10 in the axial direction AX2 and abuts against a third member 230. The side lip portion 50 has a first lip portion 51 and a second lip portion 52 branching off from the first lip portion 51 and positioned radially outward relative to the first lip portion 51 .

[0011] According to this embodiment, the side lip portion 50 has a first lip portion 51 and a second lip portion 52 that branches off from the first lip portion 51 and is located radially outward from the first lip portion 51. Therefore, when the third member 230 becomes eccentric relative to the first member 210 or the second member 220, the first lip portion 51 and the second lip portion 52 tilt together, and the state where the first lip portion 51 seals (FIG. 3) can be shifted to the state where the second lip portion 52 seals (FIG. 4). Therefore, the sealing state by the side lip portion 50 can be maintained even when the third member 230 becomes eccentric.

[0012] Here, the sealing device 100 can be used, for example, as a plug tube seal of an internal combustion engine, and in this embodiment, an example will be described in which the sealing device 100 is a plug tube seal. In this case, the first member 210 is, for example, a head cover of an internal combustion engine, the second member 220 is a plug tube, and the third member 230 is a coil body of a plug top coil 240 (FIG. 2) of an ignition device. However, the present invention is not limited to this example, and the sealing device 100 may be used as an injection pipe seal of an internal combustion engine. In this case, the second member 220 is an injection pipe. Furthermore, the sealing device 100 may be used in other applications, for example, in various connection structures provided in machines such as automobiles, industrial machines, and construction machines.

[0013] This will be explained in more detail below. In the following explanation, unless otherwise specified, the explanation of the shape of each part of the sealing device 100 and the explanation of the positional relationship between each part of the sealing device 100 are assumed to be explanations of the sealing device 100 in its natural state when no external force is acting on it. Moreover, the sealing device 100 is disposed so that a central axis AX1 of the sealing device 100 approximately coincides with the axis of the second member 220. Moreover, the central axis AX1 of the sealing device 100 and the axis of the second member 220 are disposed approximately along the axial direction AX2 of the insertion hole 211 of the first member 210. In the following description, a direction perpendicular to the central axis AX1 is referred to as a radial direction. In the radial direction, a direction away from the central axis AX1 is referred to as a radially outer direction, and a direction approaching the central axis AX1 is referred to as a radially inner direction. Moreover, the direction going around the central axis AX1 is referred to as the circumferential direction. Further, the direction along the central axis AX1 may be simply referred to as the axial direction (of the sealing device 100). The axial direction of the sealing device 100 generally coincides with the axial direction AX2 of the insertion hole 211. In addition, in the direction along the central axis AX1, one side based on the sealing device 100 (the left side in Figures 1 and 2, the upper side in Figures 3 and 4) is the third member 230 side, and the other side (the right side in Figures 1 and 2, the lower side in Figures 3 and 4) is the side away from the third member 230.

[0014] As described above, the sealing device 100 comprises an annular main body portion 10 having an abutment portion 11, a seal lip portion 30 extending radially inward from the main body portion 10, and a side lip portion 50 extending from the main body portion 10 in the axial direction AX2. Furthermore, the sealing device 100 includes, for example, a flange portion 20 extending radially outward from the body portion 10 .

[0015] The main body 10 is formed, for example, in a cylindrical shape centered on a central axis AX1. The outer circumferential surface of the main body 10 constitutes a contact portion 11 that contacts an inner circumferential surface 211a of the first member 210. The main body 10 is formed into a three-dimensional shape that corresponds to the movement trajectory of the cut end surface shape of the main body 10 shown on one side (e.g., the upper side) of the central axis AX1 in Figure 1 when the cut end surface shape is rotated once around the central axis AX1.

[0016] The flange portion 20 extends radially outward from an end portion on one side (the left side in FIG. 1) of the main body portion 10, for example. The flange portion 20 is formed, for example, in a plate shape that is substantially perpendicular to the central axis AX1. The flange portion 20 is formed into a three-dimensional shape that corresponds to the movement trajectory of the cut end surface shape of the flange portion 20 shown on one side (e.g., the upper side) of the central axis AX1 in Figure 1 when the cut end surface shape is rotated once around the central axis AX1.

[0017] The seal lip portion 30 extends, for example, radially inward from the end portion on the other side (the right side in FIG. 1) of the main body portion 10. More specifically, for example, the seal lip portion 30 extends obliquely from the end portion on the other side of the main body portion 10 toward one side (the left side in FIG. 1). The seal lip portion 30 is formed in a three-dimensional shape that corresponds to the movement trajectory of the cut end surface shape of the seal lip portion 30 shown on one side (e.g., the upper side) of the central axis AX1 in Figure 1 when the cut end surface shape is rotated once around the central axis AX1.

[0018] The side lip portion 50 is also called a muddy water lip, and forms a seal area between itself and the third member 230 to prevent the intrusion of foreign matter such as water or mud. As described above, the side lip portion 50 has the first lip portion 51 and the second lip portion 52. The first lip portion 51 extends, for example, to one side (the left side in FIG. 1) from an end portion on one side (the left side in FIG. 1) of the main body portion 10. More specifically, the first lip portion 51 is inclined, for example, in a direction toward the radially outward direction toward one side (the left side in FIG. 1). The second lip portion 52 branches off from the middle of the first lip portion 51 and extends to one side (the left side in FIG. 1) from the branching portion (crotch portion 53) with the first lip portion 51. More specifically, the second lip portion 52 also inclines, for example, in a direction toward the radially outward side toward the one side (the left side in FIG. 1). The side lip portion 50 is formed in a three-dimensional shape that corresponds to the movement trajectory of the cut end surface shape of the side lip portion 50 shown on one side (e.g., the upper side) of the central axis AX1 in Figure 1 when the cut end surface shape is rotated once around the central axis AX1.

[0019] Thus, in the natural state, each of the first lip portion 51 and the second lip portion 52 is inclined radially outwardly toward the third member 230 side (one side). This allows the first lip portion 51 to be stably pressed against the third member 230 (a side lip abutment surface 231, described later) when the sealing device 100 is attached as shown in Fig. 2. Also, even when the third member 230 transitions to a state in which it is sealed by the second lip portion 52 due to eccentricity of the third member 230, the second lip portion 52 can be stably pressed against the third member 230 (Fig. 4).

[0020] In a natural state, a tip 51a (FIG. 3) of the first lip portion 51 is located closer to the third member 230 than a tip 52a (FIG. 3) of the second lip portion 52. This allows the first lip portion 51 to be more reliably pressed against the third member 230 (the side lip abutment surface 231 thereof) when the sealing device 100 is attached as shown in Figs. Furthermore, for example, as shown in Figures 2 and 3, when the sealing device 100 is installed (when no eccentricity of the third member 230 occurs), it is possible to keep the second lip portion 52 separated from the side lip abutment surface 231 of the third member 230.

[0021] In this embodiment, the thickness dimension of the side lip portion 50 is smaller at the base end of the side lip portion 50 (thickness dimension D2 shown in Figure 3) than at the branch portion (crotch portion 53) between the first lip portion 51 and the second lip portion 52 (thickness dimension D1 shown in Figure 3). Here, the thickness dimension D1 of the side lip portion 50 at the branched portion is the smallest among the thickness dimensions passing through the crotch portion 53 (FIG. 3) between the first lip portion 51 and the second lip portion 52. The base end of the side lip portion 50 is a base end portion 51 c of the first lip portion 51 . The thickness dimension D2 at the base end (base end 51c) of the side lip portion 50 is smaller than the thickness dimension D1 at the branch point between the first lip portion 51 and the second lip portion 52, which means that a portion of the side lip portion 50 that is thinner than the thickness dimension D1 is present on the base end side of the crotch portion 53. With this configuration, the base end (base end 51c) of the side lip portion 50 becomes easier to bend, thereby smoothing the switching operation from a state in which sealing is performed by the first lip portion 51 (Figure 3) to a state in which sealing is performed by the second lip portion 52 (Figure 4). In the side lip portion 50, the portion having a thickness smaller than the thickness dimension D1 is preferably located closer to the tip side of the side lip portion 50 than the base end of the side lip portion 50 (root: base end 51d of the first lip portion 51 (Figure 3)). This makes it possible to more smoothly switch from a state in which the first lip portion 51 is sealed (Figure 3) to a state in which the second lip portion 52 is sealed (Figure 4).

[0022] In this embodiment, the distance (distance L2 shown in FIG. 3) from the branch portion (crotch portion 53) between the first lip portion 51 and the second lip portion 52 to the tip 52a of the second lip portion 52 is longer than the distance (distance L1 shown in FIG. 3) from the branch portion (crotch portion 53) to the tip 51a of the first lip portion 51. In other words, the length of the second lip portion 52 is longer than the length of the portion of the first lip portion 51 on the tip side beyond the crotch portion 53. This makes it possible to more reliably obtain sealing performance by the second lip portion 52 when eccentricity of the third member 230 occurs to such an extent that the sealing performance by the first lip portion 51 is reduced as shown in FIG.

[0023] In the case of this embodiment, in a natural state, the inclination angle (inclination angle with respect to the central axis AX1) of the end face 52b (FIG. 3) on the tip side of the second lip portion 52 is smaller than the inclination angle (inclination angle with respect to the central axis AX1) of the end face 51b (FIG. 3) on the tip side of the first lip portion 51. In other words, the end face 52b is inclined at a gentler angle with respect to the central axis AX1 than the end face 51b. As a result, when no eccentricity occurs in the third member 230 as shown in Figure 3, the end face 51b of the first lip portion 51 can be stably pressed against the side lip abutment surface 231 of the third member 230, and when eccentricity occurs in the third member 230 as shown in Figure 4, the end face 52b of the second lip portion 52 can be stably pressed against the side lip abutment surface 231.

[0024] The sealing device 100 is composed of, for example, a seal body component 60, a reinforcing ring 70, and a garter spring 80, each of which will be described below.

[0025] The seal body constituent member 60 is made of an elastic body. The seal body constituent member 60 is, for example, integrally molded as a whole, and is configured to include the side lip portion 50 and the seal lip portion 30, and also configures the flange portion 20. The seal body constituent member 60 is formed in a three-dimensional shape that corresponds to the movement trajectory of the cut end surface shape of the seal body constituent member 60 shown on one side (e.g., the upper side) of the central axis AX1 in Figure 1 when the cut end surface shape is rotated once around the central axis AX1.

[0026] The elastic body constituting the seal body constituent member 60 is made of a highly elastic material (rubber-like elastic body) such as rubber (synthetic rubber or natural rubber) or a thermoplastic elastomer (thermoplastic resin rubber elastic body), and has flexibility. Examples of materials for the seal body constituent member 60 include rubber materials such as nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR), acrylic rubber (ACM), fluororubber (FKM), and ethylene propylene diene rubber (EPDM). The seal body component 60 is integrally formed with the reinforcing ring 70 . For example, the reinforcing ring 70 (and garter spring 80, described below, if necessary) is placed in a molding die (not shown), an uncrosslinked rubber material is injected, and then the inside of the cavity of the molding die is heated and pressurized to crosslink the rubber material, thereby forming the seal body component 60 by insert molding with the reinforcing ring 70 as an insert item. This insert molding produces the seal body component 60 in a state where it is joined to the reinforcing ring 70 by vulcanization adhesion.

[0027] From the viewpoint of satisfying required characteristics such as rigidity, the reinforcing ring 70 is made of a material having a higher Young's modulus than the material constituting the seal body constituent member 60. The reinforcing ring 70 is made of, for example, a metal material or a resin material. The reinforcing ring 70 is formed, for example, in an L-shaped cross-section, integrally comprising a cylindrical portion embedded inside the main body portion 10 and a donut-shaped plate portion embedded inside the flange portion 20. The reinforcing ring 70 is formed in a three-dimensional shape that corresponds to the movement trajectory of the cut end surface shape of the reinforcing ring 70 shown on one side (e.g., the upper side) of the central axis AX1 in Figure 1 when the cut end surface shape is rotated once around the central axis AX1.

[0028] When the reinforcing ring 70 is made of a metal material, examples of the material of the reinforcing ring 70 include stainless steel (SUS) or cold rolled steel (SPCC). When the reinforcing ring 70 is made of a metal material, the reinforcing ring 70 is produced by, for example, pressing or forging.

[0029] When the reinforcing ring 70 is made of a resin material, examples of the material of the reinforcing ring 70 include polyether ether ketone (PEEK), polyphenylene sulfide (PPS), polytetrafluoroethylene (PTFE), etc. This resin material may contain, as necessary, a fiber base material such as glass fiber, organic fiber, metal fiber, carbon fiber, or mineral fiber, or may contain a particulate filler made of a metal oxide such as alumina, a metal hydroxide such as aluminum hydroxide, or a nitride such as boron nitride. When the reinforcing ring 70 is made of a resin material, the reinforcing ring 70 is manufactured by, for example, injection molding.

[0030] The garter spring 80 is made of a coil spring, both ends of which are connected to each other, and the axis of the coil spring is looped in an annular shape. The axis of the coil spring goes around the central axis AX1 once. That is, the garter spring 80 is formed in an annular shape along the circumferential direction. The garter spring 80 is a tension-type coil spring that exerts a biasing force in a direction that shortens its axial length. Because the garter spring 80 has an annular loop shape, the garter spring 80 exerts a biasing force in a direction that shortens the radius of the loop. The garter spring 80 is disposed in a groove formed in the tip portion of the seal lip portion 30, and biases the seal lip portion 30 radially inward. Thus, the garter spring 80 serves to restrain the seal lip portion 30 against the second member 220. This allows the inner peripheral edge of the seal lip portion 30 to be pressed against the outer peripheral surface 220a of the second member 220 in an excellent manner.

[0031] The sealing device 100 is configured as described above, and is attached, for example, as described below. As shown in FIG. 2, the first member 210 (head cover) has, for example, a portion in which the diameter dimension changes stepwise, and the portion of the sealing device 100 from the main body portion 10 to the flange portion 20 is arranged in close contact with the inner circumferential surface of that portion of the first member 210. The second member 220 is coaxially inserted into the insertion hole 211 of the first member 210. The inner peripheral edge of the seal lip portion 30 is circumferentially pressed against an outer peripheral surface 220a of the second member 220. A plug top coil 240 is disposed inside the first member 210 (head cover). The plug top coil 240 has a large-diameter coil body and a small-diameter shaft portion 241 extending from the coil body. The shaft portion 241 is inserted into the second member 220, and the coil body is disposed outside the second member 220. In the present embodiment, the third member 230 is the coil body of the plug top coil 240, and the side lip portion 50 is pressed against a side lip abutment surface 231 of the third member 230 in a circumferential manner. The side lip abutment surface 231 is substantially perpendicular to the axial direction AX2 of the insertion hole 211.

[0032] Here, a sealing device 1000 according to a comparative embodiment will be described with reference to FIGS. The sealing device 1000 of the comparative embodiment differs from the sealing device 100 of this embodiment in that it has a side lip portion 1050 instead of the side lip portion 50, but in other respects is configured similarly to the sealing device 100. The side lip portion 1050 has a configuration corresponding to the first lip portion 51 in the sealing device 100 according to this embodiment, and does not have a portion corresponding to the second lip portion 52 in the sealing device 100. The seal body constituent member 1060 of the sealing device 1000 differs from the seal body constituent member 60 of the sealing device 100 in that it does not have a portion corresponding to the second lip portion 52, but is otherwise configured similarly to the seal body constituent member 60 of the sealing device 100. In the case of the sealing device 1000 of the comparative embodiment, as shown in FIG. 5, when no eccentricity occurs in the third member 230, the tip of the side lip portion 1050 is pressed circumferentially against the side lip abutment surface 231 of the third member 230, thereby ensuring sealing performance by the side lip portion 1050. On the other hand, as shown in FIG. 6, when eccentricity occurs in the third member 230, the side lip portion 1050 may be turned up, and the sealing performance of the side lip portion 1050 may be reduced.

[0033] In contrast, in the case of this embodiment, as shown in Figure 4, even if eccentricity of the third member 230 occurs and the third member 230 moves relative to the sealing device 100 in the direction of arrow A shown in Figure 4, causing the first lip portion 51 to roll up and reducing the sealing ability provided by the first lip portion 51, the second lip portion 52 can be stably pressed against the side lip abutment surface 231 of the third member 230, so that the sealing ability provided by the side lip portion 50 can be maintained. That is, as a result of a circumferential portion of the side lip portion 50 tilting in a direction approaching the central axis AX1 of the sealing device 100, the circumferential portion of the side lip portion 50 transitions from an original state (state in FIG. 3) in which sealing performance was ensured by the first lip portion 51 to a state (state in FIG. 4) in which sealing performance is ensured by the second lip portion 52. As a result, in the case of this embodiment, it is possible to maintain the sealing state provided by the side lip portion 50 even when the third member 230 is eccentric. 4 is a direction substantially perpendicular to the central axis AX1 of the sealing device 100 and the axial direction AX2 of the insertion hole 211. Similarly, the direction of arrow A in FIG. 6 is a direction substantially perpendicular to the central axis of the sealing device 1000 and the axial direction AX2 of the insertion hole 211.

[0034] Although the embodiment has been described above with reference to the drawings, this is merely an example of the present invention, and various configurations other than those described above can also be adopted. For example, in the above, an example was described in which the thickness dimension D2 shown in Figure 3 is smaller than the thickness dimension D1 shown in Figure 3, but the thickness dimension D1 and the thickness dimension D2 may be the same as each other, or the thickness dimension D2 may be larger than the thickness dimension D1. In addition, in the above, an example has been described in which the distance L2 shown in FIG. 3 is longer than the distance L1 shown in FIG. 3, but the distances L1 and L2 may be the same as each other, or the distance L1 may be longer than the distance L2. In the above description, an example has been described in which the inclination angle of the end face 52b with respect to the central axis AX1 is smaller than the inclination angle of the end face 51b with respect to the central axis AX1 in the natural state. The inclination angle of end face 51b relative to central axis AX1 and the inclination angle of end face 52b relative to central axis AX1 may be the same, or the inclination angle of end face 51b relative to central axis AX1 may be smaller than the inclination angle of end face 52b relative to central axis AX1. In the above, an example has been described in which the entire first lip portion 51 extends linearly (an example in which the overall shape of the side lip portion 50 is a lowercase Y shape) with respect to the cut end shape along the central axis AX1, but the portion of the first lip portion 51 on the tip side of the crotch portion 53 may be inclined relative to the base end portion 51c (the portion on the base end side of the crotch portion 53) of the first lip portion 51. In other words, the overall shape of the side lip portion 50 on the cut end shape along the central axis AX1 may be an uppercase Y shape.

[0035] The present embodiment encompasses the following technical ideas. (1) A sealing device that is disposed in a gap between an inner circumferential surface of an insertion hole formed in a first member, an outer circumferential surface of a second member inserted into the insertion hole, and a third member located on one side of the second member in an axial direction of the insertion hole, and seals the gap, an annular main body portion having an abutment portion that abuts against the inner circumferential surface of the first member; a seal lip portion extending radially inward from the main body portion and contacting the outer circumferential surface of the second member; A side lip portion extending from the main body portion in the axial direction and abutting against the third member; Equipped with The side lip portion is a sealing device having a first lip portion and a second lip portion branching off from the first lip portion and positioned radially outward from the first lip portion. (2) The sealing device described in (1) above, in a natural state, each of the first lip portion and the second lip portion is inclined radially outward as it approaches the third member. (3) The sealing device according to (1) or (2), in which, in a natural state, a tip of the first lip portion is located closer to the third member than a tip of the second lip portion. (4) A sealing device described in any one of (1) to (3), wherein the thickness dimension of the side lip portion at the base end of the side lip portion is smaller than the dimension at the branching portion between the first lip portion and the second lip portion. (5) A sealing device described in any one of (1) to (4), wherein the distance from the branch portion between the first lip portion and the second lip portion to the tip of the second lip portion is longer than the distance from the branch portion to the tip of the first lip portion. [Explanation of symbols]

[0036] 10 Main body 11 Contact part 20 Flange 30 Seal lip 50 Side lip part 51 First lip 51a Tip 51b End face 51c Proximal end 51d proximal end 52 Second lip 52a Tip 52b End face 53 Crotch (branch) 60 Seal body components 70 Reinforcement Ring 80 Garter Spring 100 Sealing device 210 First member 211 Insertion hole 211a Inner surface 220 Second member 220a Outer surface 230 Third member 231 Side lip contact surface 240 Plug Top Coil 241 Shaft 250 gap 1000 Sealing device 1050 Side lip part 1060 Seal body components

Claims

1. A sealing device that is disposed in a gap between an inner circumferential surface of an insertion hole formed in a first member, an outer circumferential surface of a second member inserted into the insertion hole, and a third member located on one side of the second member in an axial direction of the insertion hole, and seals the gap, an annular main body portion having an abutment portion that abuts against the inner circumferential surface of the first member; a seal lip portion extending radially inward from the main body portion and contacting the outer circumferential surface of the second member; A side lip portion extending in an axial direction from the main body portion and abutting against the third member; Equipped with The side lip portion is a sealing device having a first lip portion and a second lip portion branching off from the first lip portion and positioned radially outward from the first lip portion.

2. The sealing device according to claim 1 , wherein in a natural state, each of the first lip portion and the second lip portion is inclined radially outwardly as it approaches the third member.

3. The sealing device according to claim 1 or 2, wherein in a natural state, a tip end of the first lip portion is located closer to the third member than a tip end of the second lip portion.

4. The sealing device according to claim 1 or 2, wherein a thickness dimension of the side lip portion at a base end portion of the side lip portion is smaller than a thickness dimension at a branch portion between the first lip portion and the second lip portion.

5. 3. The sealing device according to claim 1, wherein a distance from a branch portion between the first lip portion and the second lip portion to a tip of the second lip portion is longer than a distance from the branch portion to a tip of the first lip portion.

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