Sealing device

Abstract

A seal device having high sound insulation and imparting less torque to a rotating shaft is provided. The seal device is used to seal a gap between an outer support member and a rotating shaft configured inside a hole provided in the outer support member. The seal device has a mounting portion mounted to the outer support member, a cylindrical portion configured inside the mounting portion, a sliding portion configured inside the cylindrical portion and in slidable contact with an outer peripheral surface of the rotating shaft, and a corrugated portion made of an elastic body interposed between the mounting portion and the cylindrical portion. The corrugated portion has an outer inclined portion having a circular truncated cone shape, an inner inclined portion having a circular truncated cone shape inclined toward a direction opposite to the outer inclined portion, and a curved portion connecting the outer inclined portion and the inner inclined portion. The outer inclined portion has an outer thick wall portion thicker than the curved portion. The inner inclined portion has an inner thick wall portion thicker than the curved portion.

Description

Technical Field

[0001] This invention relates to a sealing device suitable for use as a steering dust seal. Background Technology

[0002] A steering dust seal is disposed on the front bulkhead of a vehicle, and a steering shaft is rotatably inserted therein (Patent Document 1). The steering dust seal has a portion that allows the steering shaft to slide when it rotates.

[0003] The steering dust seal prevents foreign objects (dust, mud, water, etc.) from entering the passenger compartment from the engine compartment and also suppresses sound transmission from the engine compartment to the passenger compartment. To allow the driver to adjust the steering shaft angle, the steering dust seal has a corrugated portion made of an elastic material.

[0004] Patent documents Patent Document 1: International Publication No. 2020 / 250577 Summary of the Invention The technical problem that the invention aims to solve In recent years, there has been a growing demand for a quieter cabin. Furthermore, it is desirable for the steering dust seal to exert minimal resistance, or torque, on the steering shaft during rotation.

[0005] Therefore, the present invention provides a sealing device with high sound insulation and low torque applied to the rotating shaft.

[0006] Technical solutions to solve technical problems One aspect of the present invention provides a sealing device for sealing a gap between an outer support member and a rotating shaft disposed inside a hole provided in the outer support member. The sealing device comprises: an annular mounting portion mounted in the hole of the outer support member; a cylindrical portion disposed radially inside the mounting portion; a sliding portion disposed radially inside the cylindrical portion and slidably contacting the outer circumferential surface of the rotating shaft; and a corrugated portion, made of an elastomer, located between the mounting portion and the cylindrical portion. The corrugated portion comprises: an outer inclined portion having a frustum shape; an inner inclined portion having a frustum shape and inclined in the opposite direction to the outer inclined portion; and a curved portion having a curved cross-sectional shape and connecting the outer inclined portion and the inner inclined portion. The outer inclined portion has an outer thick-walled portion, the thickness of which is greater than the thickness of the curved portion. The inner inclined portion has an inner thick-walled portion, the thickness of which is greater than the thickness of the curved portion.

[0007] In this respect, the outer and inner inclined portions of the corrugated section are provided with outer and inner thick-walled portions, respectively. These thick-walled portions effectively suppress the transmission of noise from the engine compartment to the passenger compartment. On the other hand, the thickness of the curved portion of the corrugated section is small, making it easy to deform, thus reducing the resistance, i.e., torque, exerted on the rotating shaft by the sealing device. Especially in low-temperature environments, even if the elastomer forming the corrugated section hardens, the thinner curved portion is easy to deform. Because the resistance exerted on the rotating shaft is small, the noise generated by the sliding of the rotating shaft and the sliding portion is also reduced. Attached Figure Description

[0008] Figure 1 This is a partial cross-sectional perspective view of the sealing device in an embodiment of the present invention.

[0009] Figure 2 This is a cross-sectional view of the aforementioned sealing device.

[0010] Figure 3 This is a cross-sectional view of the sealing device in its operating state.

[0011] Figure 4 This is a cross-sectional view showing the state of the first sealing part of the sealing device manufactured using a mold.

[0012] Figure 5 This is a cross-sectional view showing the state of the second sealing part of the sealing device manufactured using a mold.

[0013] Figure 6 This is a partial cross-sectional perspective view showing a sealing device according to another embodiment of the present invention. Detailed Implementation

[0014] Hereinafter, various embodiments of the present invention will be described with reference to the accompanying drawings. The scale of the drawings may not be accurate, and some features may be exaggerated or omitted.

[0015] like Figures 1 to 3 As shown, the sealing device 1 in this embodiment of the invention has a composite structure with two sealing parts 10 and 50 (a first sealing part 10 and a second sealing part 50). Each of the sealing parts 10 and 50 is an annular component centered on the central axis Ax. Figures 1 to 3 The cross-section shown is a plane containing the central axis Ax.

[0016] like Figure 3 As shown, the sealing device 1 in this embodiment is a steering dust seal used to seal the gap between the outer support member 2 and the rotating shaft (steering shaft) 4, wherein the rotating shaft 4 is disposed inside the hole 2A provided in the outer support member 2. The rotating shaft 4 rotates about axis Bx. Figure 3 In the attached diagram, E indicates the space on the engine compartment side, and P indicates the space on the crew compartment side.

[0017] The outer support member 2 can be the front bulkhead of the vehicle. Alternatively, the outer support member 2 can also be a cylindrical member fixed to the front bulkhead (an accessory member for mounting the sealing device 1 to the front bulkhead).

[0018] An internal combustion engine (not shown) or an electric motor (not shown) may be installed in the engine compartment.

[0019] The bore 2A has: a large-diameter bore portion 2B that opens into space P on the crew compartment side; and a small-diameter bore portion 2C adjacent to the large-diameter bore portion 2B and disposed further towards the engine compartment side than the large-diameter bore portion 2B. Both the large-diameter bore portion 2B and the small-diameter bore portion 2C are circular bores. In the ideal case where the sealing device 1 is concentrically installed in the bore 2A, the central axis Ax of the sealing device 1 is also the central axis of the bore 2A.

[0020] The sealing device 1 has sealing parts 10 and 50, but each of the sealing parts 10 and 50 can be regarded as a sealing device (turning dust seal).

[0021] The first sealing portion (first sealing device) 10 is essentially a highly elastic component made of an elastomer. The sealing portion 10 has: an annular mounting portion 11, mounted in the hole 2A of the outer support member 2; a cylindrical portion 12, disposed radially inside the mounting portion 11; and a corrugated portion 13, located between the mounting portion 11 and the cylindrical portion 12 and connecting the two. Furthermore, the sealing portion 10 has a sliding portion 14, disposed radially inside the cylindrical portion 12, and slidably contacting the outer peripheral surface of the rotating shaft 4.

[0022] The mounting portion 11 has: an elastic ring 15 made of an elastomer; and a rigid ring 16 fixed around the elastic ring 15 and made of a rigid material (e.g., metal).

[0023] The rigid ring 16 has a generally L-shaped cross-sectional shape. That is, the rigid ring 16 has a cylindrical sleeve 16a and a flange 16b extending radially outward from one end of the sleeve 16a. The sleeve 16a is fitted (pressed into) in the large-diameter hole 2B of the hole 2A of the outer support member 2.

[0024] Most of the elastic ring 15 is disposed radially inside the rigid ring 16. However, a portion of the elastic ring 15 is fixed to the outer peripheral surface of the flange 16b on the passenger compartment side, the outer peripheral surface of the flange 16b, and the outer peripheral portion of the surface of the flange 16b on the engine compartment side. With the seal 10 installed in the hole 2A, the portion 15a of the elastic ring 15 fixed to the outer peripheral portion of the surface of the flange 16b on the engine compartment side is compressed along the central axis Ax between the end face of the outer support member 2 and the sleeve 16a of the rigid ring 16. Therefore, the portion 15a seals the gap between the rigid ring 16 and the outer support member 2, reducing the intrusion of foreign objects from the passenger compartment side space P into the engine compartment side space E, and preventing corrosion of the rigid ring 16 and / or the outer support member 2.

[0025] The end 16c of sleeve 16a, opposite to flange 16b, has a smaller diameter than the rest of sleeve 16a. End 16c is surrounded by portion 15b of elastic ring 15. Portion 15b has a radial lip 15c and an axial lip 15d. With sealing portion 10 installed in bore 2A, radial lip 15c is pressed against the inner circumferential surface of large-diameter bore portion 2B of bore 2A and deformed radially inward, sealing the gap between end 16c and outer support member 2. Furthermore, in this state, axial lip 15d is pressed against the stepped portion between large-diameter bore portion 2B and small-diameter bore portion 2C of bore 2A and compressed, sealing the gap between end 16c and outer support member 2. Therefore, radial lip 15c and axial lip 15d reduce the intrusion of foreign objects from engine compartment side space E into passenger compartment side space P.

[0026] The cylindrical portion 12 and the corrugated portion 13 are made of the same elastic body as the elastic ring 15 of the mounting portion 11. Preferably, the elastic ring 15, the cylindrical portion 12 and the corrugated portion 13 are integrally formed.

[0027] The sliding part 14 disposed inside the cylindrical part 12 is made of a resin material that is harder than an elastomer and has a low coefficient of friction. Preferred resin materials include, for example, polytetrafluoroethylene (PTFE), polyetheretherketone (PEEK), and polyphenylene sulfide (PPS).

[0028] The sliding part 14 can be fixed to the cylindrical part 12 by an adhesive. Alternatively, the sliding part 14 can have a protrusion, which is fitted into a groove formed in the cylindrical part 12 to fix the sliding part 14 to the cylindrical part 12.

[0029] When the rotating shaft 4 rotates, the outer peripheral surface of the rotating shaft 4 slides relative to the inner peripheral surface of the sliding part 14. Since the sliding part 14 is made of resin with a low coefficient of friction, even if the rotating shaft 4 rotates, the abnormal noise caused by the friction between the outer peripheral surface of the rotating shaft 4 and the inner peripheral surface of the sliding part 14 can be reduced.

[0030] While not absolutely necessary, grease can be applied between the inner circumferential surface of the sliding portion 14 and the outer circumferential surface of the rotating shaft 4. The grease further reduces friction between the outer circumferential surface of the rotating shaft 4 and the inner circumferential surface of the sliding portion 14. Multiple grooves for retaining the grease can be formed on the inner circumferential surface of the sliding portion 14.

[0031] A radial lip 12a is formed at the end of the cylindrical portion 12 on the occupant compartment side. The radial lip 12a extends radially inward toward the occupant compartment side. The radial lip 12a constrains the sliding portion 14 and applies a binding force to the sliding portion 14. The front end of the radial lip 12a can also slidably contact the outer peripheral surface of the rotating shaft 4.

[0032] The rotating shaft 4 is a steering shaft installed in the vehicle's tilt steering mechanism. Therefore, the rotating shaft 4 can be tilted by the driver. That is, the angle of the rotating shaft 4 relative to the hole 2A of the outer support member 2 is adjustable. Furthermore, the rotating shaft 4 may be eccentric relative to the hole 2A. The corrugated portion 13 is made of an elastomer and has a curved shape, thus readily undergoing elastic deformation. Through the elastic deformation of the corrugated portion 13, the rotating shaft 4 is allowed to move (i.e., tilt and eccentricate), and the sliding portion 14 can still contact the outer peripheral surface of the rotating shaft 4. Figure 3 The state of the rotating shaft 4 being tilted and eccentric relative to the hole 2A is shown.

[0033] The corrugated portion 13 has an inclined portion 20, a curved portion 21, an inclined portion 22, a curved portion 23, an inclined portion 24, a curved portion 25, and an inclined portion 26. The inclined portions 20, 22, 24, and 26 are in the shape of a frustum. However, the inclination direction of the inclined portions 20 and 24 is opposite to the inclination direction of the inclined portions 22 and 26.

[0034] The inclined portion 20 is connected to the passenger compartment side end edge of the cylindrical portion 12 and extends toward the passenger compartment side. The area of ​​the circular region surrounded by the passenger compartment side end edge of the inclined portion 20 is larger than the area of ​​the circular region surrounded by the engine compartment side end edge of the inclined portion 20 connected to the sliding portion 14.

[0035] The curved portion 21 has a curved cross-sectional shape, connecting the end edge of the inclined portion 20 on the passenger compartment side to the end edge of the inclined portion 22 on the passenger compartment side.

[0036] The inclined section 22 extends from the curved section 21 toward the engine compartment side. The area of ​​the circular region enclosed by the engine compartment side edge of the inclined section 22 is larger than the area of ​​the circular region enclosed by the passenger compartment side edge of the inclined section 22 connected to the curved section 21.

[0037] The curved portion 23 has a curved (arc-shaped) cross-sectional shape, connecting the engine compartment side end edge of the inclined portion 22 and the engine compartment side end edge of the inclined portion 24.

[0038] The inclined section 24 extends from the curved section 23 toward the passenger compartment side. The area of ​​the circular region enclosed by the passenger compartment side edge of the inclined section 24 is larger than the area of ​​the circular region enclosed by the engine compartment side edge of the inclined section 24 connected to the curved section 23.

[0039] The curved portion 25 has a curved (arc-shaped) cross-sectional shape, connecting the end edge of the inclined portion 24 on the passenger compartment side to the end edge of the inclined portion 26 on the passenger compartment side.

[0040] The inclined portion 26 extends from the curved portion 25 toward the engine compartment side and is connected to the elastic ring 15 of the mounting portion 11. The area of ​​the circular region enclosed by the engine compartment side end edge of the inclined portion 26 connected to the elastic ring 15 is larger than the area of ​​the circular region enclosed by the passenger compartment side end edge of the inclined portion 26 connected to the curved portion 25.

[0041] Thus, the inclined portion 22 is disposed radially outside the inclined portion 20, the inclined portion 24 is disposed radially outside the inclined portion 22, and the inclined portion 26 is disposed radially outside the inclined portion 24. Therefore, for the inclined portion 20, the inclined portion 22 is the outer inclined portion, for the inclined portion 22, the inclined portion 24 is the outer inclined portion, and for the inclined portion 24, the inclined portion 26 is the outer inclined portion.

[0042] In the following description, the thickness of the various portions of the sealing portion 10 refers to the thickness of the sealing portion 10 when no elastic deformation has occurred.

[0043] like Figure 2 As shown, the inclined portion 20 has a uniform thickness t1, and the inclined portion 26 also has a uniform thickness t2.

[0044] Focusing on the inclined portions 22 and 24, and the adjacent curved portions 21, 23 and 25. With respect to the inclined portion 22, the inclined portion 24 is the outer inclined portion, and with respect to the inclined portion 24, the inclined portion 22 is the inner inclined portion.

[0045] like Figure 2 As shown, the curved portion 23 has an arc-shaped cross-section and a uniform thickness t3. The curved portion 25 also has an arc-shaped cross-section and a uniform thickness t4. The thickness of the curved portion 21 is not uniform; at a position adjacent to the inclined portion 22, the curved portion 21 has a minimum thickness t5. The thicknesses t2, t3, t4, and the minimum thickness t5 are approximately equal.

[0046] The outer inclined portion 24 has an outer thin-walled portion 30, an outer thickness-varying portion 31, an outer thick-walled portion 32, an outer thickness-varying portion 33, and an outer thin-walled portion 34. The outer thin-walled portion 30 is connected to the curved portion 23 and has the same uniform thickness t3 as the curved portion 23. The outer thick-walled portion 32 has a uniform thickness t6 that is greater than the thickness t3 of both the curved portion 23 and the outer thin-walled portion 30. The outer thickness-varying portion (first outer thickness-varying portion) 31 connects the outer thin-walled portion 30 and the outer thick-walled portion 32, and its thickness gradually and linearly increases from the outer thin-walled portion 30 toward the outer thick-walled portion 32.

[0047] The outer thickness variation portion (second outer thickness variation portion) 33 extends in the opposite direction from the outer thick-walled portion 32 toward the outer thickness variation portion 31. The outer thin-walled portion 34 connects the outer thickness variation portion 33 and the curved portion 25. The thickness of the outer thin-walled portion 34 gradually and linearly increases from the curved portion 25 toward the outer thickness variation portion 33. Therefore, the end of the outer thin-walled portion 34 on the curved portion 25 side locally has the same thickness t4 as the curved portion 25. The outer thickness variation portion 33 has a thickness that increases sharply and linearly from the outer thin-walled portion 34 toward the outer thick-walled portion 32. In other words, the outer thickness variation portion 33 has a thickness that decreases linearly from the outer thick-walled portion 32 toward the outer thin-walled portion 34. The thickness t6 of the outer thick-walled portion 32 is greater than the thickness t4 of the curved portion 25.

[0048] One surface of the outer inclined section 24 (the surface on the engine compartment side) is a smooth frustum shape. However, the other surface of the outer inclined section 24 (the surface on the passenger compartment side) has a protruding portion due to the variation in the thickness of the inclined section 24. Protruding portions can be formed not only on the passenger compartment side surface of the outer inclined section 24, but also on the engine compartment side surface of the outer inclined section 24.

[0049] The inner inclined portion 22 has an inner thin-walled portion 35, an inner thickness-varying portion 36, an inner thick-walled portion 37, and an inner thickness-varying portion 38. The inner thin-walled portion 35 is connected to the curved portion 23 and has the same uniform thickness t3 as the curved portion 23. The inner thick-walled portion 37 has a uniform thickness t7 that is greater than the thickness t3 of both the curved portion 23 and the inner thin-walled portion 35. The inner thickness-varying portion (first inner thickness-varying portion) 36 connects the inner thin-walled portion 35 and the inner thick-walled portion 37, and its thickness gradually and linearly increases from the inner thin-walled portion 35 toward the inner thick-walled portion 37.

[0050] The inner thickness variation section (second inner thickness variation section) 38 extends from the inner thick wall section 37 in the opposite direction to the inner thickness variation section 36, connecting the inner thick wall section 37 and the curved section 21. The inner thickness variation section 38 has a thickness that increases sharply and linearly from the curved section 21 toward the inner thick wall section 37. In other words, the inner thickness variation section 38 has a thickness that decreases linearly from the inner thick wall section 37 toward the curved section 21. Therefore, the end of the inner thickness variation section 38 on the curved section 21 side locally has the same thickness as the minimum thickness t5 of the curved section 21. The thickness t7 of the inner thick wall section 37 is greater than the thickness at any position of the curved section 21.

[0051] One surface of the inner inclined section 22 (the surface on the engine compartment side) is a smooth frustum shape. However, the other surface of the inner inclined section 22 (the surface on the passenger compartment side) has a protruding portion due to the variation in the thickness of the inclined section 22. Protruding portions can be formed not only on the passenger compartment side surface of the inner inclined section 22, but also on the engine compartment side surface of the inner inclined section 22.

[0052] In the first sealing portion 10, the outer inclined portion 24 and the inner inclined portion 22 of the corrugated portion 13 are provided with an outer thick-walled portion 32 and an inner thick-walled portion 37, respectively. These thick-walled portions 32 and 37 effectively suppress the transmission of noise from the engine compartment to the passenger compartment. On the other hand, the curved portion 23, the outer thin-walled portions 30 and 34, and the inner thin-walled portion 35 of the corrugated portion 13 are easily deformable due to their small thickness, thus reducing the resistance, i.e., torque, exerted by the sealing portion 10 on the rotating shaft 4. Especially in low-temperature environments, even if the elastomer forming the corrugated portion 13 hardens, these thin portions are easily deformable. Since the resistance exerted on the rotating shaft 4 is small, the noise generated by the sliding of the rotating shaft 4 and the sliding portion 14 is also reduced.

[0053] Preferably, the thickness t6 of the outer thick-walled portion 32 and the thickness t7 of the inner thick-walled portion 37 are at least 1.1 times the thickness t3 of the curved portion 23. In this case, the outer thick-walled portion 32 and the inner thick-walled portion 37 can effectively suppress noise transmitted from the engine compartment to the passenger compartment. In addition, since the curved portion 23 is thinner, the resistance, i.e., torque, given to the rotating shaft 4 by the sealing portion 10 can be reduced. More preferably, the thickness t6 of the outer thick-walled portion 32 and the thickness t7 of the inner thick-walled portion 37 are at least 1.3 times the thickness t3 of the curved portion 23.

[0054] Preferably, the length L4 of the outer thick-walled portion 32 is greater than 1 / 10.6 of the length L3 of the outer inclined portion 24, which has a frustum shape and includes the outer thin-walled portion 30, the first outer thickness variation portion 31, the outer thick-walled portion 32, and the second outer thickness variation portion 33. In this case, the outer thick-walled portion 32, which has a larger thickness in the frustum-shaped outer inclined portion 24, has a larger length L4, and therefore the outer inclined portion 24 has a larger weight. The outer inclined portion 24 can effectively suppress the transmission of engine compartment noise to the passenger compartment.

[0055] Furthermore, preferably, the length L2 of the inner thick-walled portion 37 is greater than 1 / 5.3 of the length L1 of the inner inclined portion 22, which has a frustum shape and includes the inner thin-walled portion 35, the first inner thickness variation portion 36, the inner thick-walled portion 37, and the second inner thickness variation portion 38. In this case, the length L2 of the inner thick-walled portion 37, which has a larger thickness in the frustum-shaped inner inclined portion 22, is larger, so the inner inclined portion 22 has a larger weight, and the inner inclined portion 22 can effectively suppress the transmission of engine compartment noise to the passenger compartment.

[0056] Furthermore, for the inner inclined portion 22, the curved portion 21 is the inner connecting portion connecting the cylindrical portion 12 and the inner inclined portion 22. The curved portion (inner connecting portion) 21 has a thickness smaller than the thickness t6 of the outer thick-walled portion 32 and the thickness t7 of the inner thick-walled portion 37. Therefore, the thinner curved portion 21 is easier to deform, which can further reduce the resistance, i.e., torque, given by the sealing portion 10 to the rotating shaft 4.

[0057] Furthermore, for the outer inclined portion 24, the curved portion 25 and the inclined portion 26 are the outer connecting portions connecting the mounting portion 11 and the outer inclined portion 24. The thickness t4 of the curved portion (outer connecting portion) 25 and the thickness t2 of the inclined portion (outer connecting portion) 26 are less than the thickness t6 of the outer thick-walled portion 32 and the thickness t7 of the inner thick-walled portion 37. Therefore, the curved portion 25 and the inclined portion 26, which have smaller thicknesses, are easier to deform, which can further reduce the resistance, i.e., the torque, given by the sealing portion 10 to the rotating shaft 4.

[0058] Preferably, the thickness t6 of the outer thick-walled portion 32 is more than 1.1 times the thickness t4 of the curved portion (outer connecting portion) 25 and the thickness t2 of the inclined portion (outer connecting portion) 26. In this case, the outer thick-walled portion 32 can effectively suppress the transmission of engine compartment noise to the passenger compartment. On the other hand, since the thickness of the curved portion (outer connecting portion) 25 and the inclined portion (outer connecting portion) 26 is small, the resistance, i.e., the torque, given to the rotating shaft 4 by the sealing device 10 can be reduced.

[0059] The outer inclined portion 24 and the inner inclined portion 22 have thickness variation portions 31, 33, 36, and 38 with gradually changing thickness. Therefore, stress concentration is less likely to occur in the outer inclined portion 24 and the inner inclined portion 22. Furthermore, as... Figure 4 As shown, when the corrugated part 13 is manufactured using molds 80 and 81, the thickness variation parts 31, 33, 36, and 38, whose thickness gradually changes, do not hinder the flow of the elastomer in the cavity inside the molds 80 and 81. Therefore, the elastomer can easily spread throughout the mold inside the corrugated part 13.

[0060] like Figure 4 As shown, the corrugated portion 13 does not have an undercut that would prevent the corrugated portion 13 from separating from the molds 80 and 81 that form the corrugated portion 13 along the axial direction. Although the outer inclined portion 24 and the inner inclined portion 22 have thickness variation portions 31, 33, 36, and 38 with gradually changing thickness, when manufacturing the corrugated portion 13 using the molds 80 and 81, the corrugated portion 13 can be easily removed from the molds 80 and 81 by separating the molds 80 and 81 along the axial direction.

[0061] In particular, the outer thick-walled portion 32 of the outer inclined portion 24 protrudes radially inward (towards the passenger compartment side) relative to the frustum shape of the outer inclined portion 24, but the inner peripheral surface (towards the passenger compartment side) of the first outer thickness variation portion 31 of the outer inclined portion 24 is approximately cylindrical, thus facilitating the separation of the mold 81 from the corrugated portion 13. Furthermore, the inner thick-walled portion 37 of the inner inclined portion 22 protrudes radially outward (towards the passenger compartment side) relative to the frustum shape of the inner inclined portion 22, but the outer peripheral surface (towards the passenger compartment side) of the first inner thickness variation portion 36 of the inner inclined portion 22 is approximately cylindrical, thus facilitating the separation of the mold 81 from the corrugated portion 13.

[0062] The second sealing part (second sealing device) 50 is also essentially a highly elastic component made of an elastomer. The sealing part 50 has: an annular mounting part 51 installed in the hole 2A of the outer support member 2; a cylindrical part 52 disposed radially inside the mounting part 51; and a corrugated part 53 that is between the mounting part 51 and the cylindrical part 52 and connects the two. Furthermore, the sealing part 50 has a sliding part 54 disposed radially inside the cylindrical part 52 and slidably in contact with the outer peripheral surface of the rotating shaft 4.

[0063] The mounting portion 51 has: an elastic ring 55 made of an elastomer; and a rigid ring 56 fixed around the elastic ring 55 and made of a rigid material (e.g., metal).

[0064] The rigid ring 56 has a generally L-shaped cross-sectional shape. That is, the rigid ring 56 has a cylindrical sleeve 56a and an inner flange 56b extending radially inward from one end of the sleeve 56a. The sleeve 56a can be directly fitted (pressed into) the hole 2A of the outer support member 2, but in this embodiment, it is fitted (pressed into) the end of the mounting portion 11 of the first sealing portion 10 and installed in the hole 2A. More specifically, the end of the mounting portion 11 in which the sleeve 56a is fitted is the end of the elastic ring 15, which is surrounded and reinforced by the end 16c of the rigid ring 16. Therefore, for the second sealing portion 50, the mounting portion 11 of the first sealing portion 10 can be regarded as the outer support member.

[0065] The elastic ring 55 is disposed radially inside the sleeve 56a of the rigid ring 56.

[0066] The rigid ring 56, which is not easily deformable, fits tightly against the inner circumferential surface of the end of the elastic ring 15, which is easily deformable, reducing the intrusion of foreign objects from the space E on the engine compartment side into the space P on the passenger compartment side.

[0067] The cylindrical portion 52 and the corrugated portion 53 are made of the same elastic body as the elastic ring 55 of the mounting portion 51. Preferably, the elastic ring 55, the cylindrical portion 52 and the corrugated portion 53 are integrally formed.

[0068] The sliding part 54, which is disposed inside the cylindrical part 52, is made of a resin material that is harder than an elastomer and has a lower coefficient of friction, just like the sliding part 14 of the sealing part 10.

[0069] The sliding part 54 can be fixed to the cylindrical part 52 by an adhesive. Alternatively, the sliding part 54 can have a protrusion, which is fitted into a groove formed in the cylindrical part 52 to fix the sliding part 54 to the cylindrical part 52.

[0070] When the rotating shaft 4 rotates, the outer peripheral surface of the rotating shaft 4 slides relative to the inner peripheral surface of the sliding part 54. Since the sliding part 54 is made of resin with a low coefficient of friction, even if the rotating shaft 4 rotates, the abnormal noise caused by the friction between the outer peripheral surface of the rotating shaft 4 and the inner peripheral surface of the sliding part 54 can be reduced.

[0071] While not absolutely necessary, grease can be applied between the inner circumferential surface of the sliding portion 54 and the outer circumferential surface of the rotating shaft 4. The grease further reduces friction between the outer circumferential surface of the rotating shaft 4 and the inner circumferential surface of the sliding portion 54. Multiple grooves for retaining the grease can be formed on the inner circumferential surface of the sliding portion 54.

[0072] A radial lip 52a is formed at the engine compartment side end of the cylindrical portion 52. The radial lip 52a faces the engine compartment side and extends radially inward. The radial lip 52a constrains the sliding portion 54 and applies a binding force to the sliding portion 54. The front end of the radial lip 52a can also slidably contact the outer peripheral surface of the rotating shaft 4.

[0073] Although not absolutely necessary, a radial lip 52b is also formed at the end of the cylindrical portion 52 on the occupant compartment side. The radial lip 52b faces the occupant compartment side and extends radially inward. The front end of the radial lip 52b slidably contacts the outer peripheral surface of the rotating shaft 4.

[0074] Although not absolutely necessary, a reinforcing ring 52c is embedded inside the cylindrical portion 52. The reinforcing ring 52c is made of a rigid material (such as metal) to suppress deformation of the cylindrical portion 52, so that the sliding portion 54 and the radial lip portion 52b can contact the rotating shaft 4 in a stable posture.

[0075] The corrugated portion 53 is made of an elastomer and has a curved shape, thus allowing for easy elastic deformation. Through the elastic deformation of the corrugated portion 53, the rotating shaft 4 is allowed to move (i.e., tilt and eccentricate), and the sliding portion 54 can contact the outer peripheral surface of the rotating shaft 4. As described above, Figure 3 The state of the rotating shaft 4 being tilted and eccentric relative to the hole 2A is shown.

[0076] The corrugated portion 53 has a curved portion 61, an inclined portion 62, a curved portion 63, an inclined portion 64, and a curved portion 65. The inclined portions 62 and 64 are in the shape of a frustum. However, the inclined direction of the inclined portion 64 is opposite to the inclined direction of the inclined portion 62.

[0077] The curved portion 61 has a curved cross-sectional shape, connecting the end edge of the cylindrical portion 52 on the passenger compartment side with the end edge of the inclined portion 62 on the passenger compartment side.

[0078] The inclined section 62 extends from the curved section 61 toward the engine compartment side. The area of ​​the circular region enclosed by the engine compartment side edge of the inclined section 62 is larger than the area of ​​the circular region enclosed by the passenger compartment side edge of the inclined section 62 connected to the curved section 61.

[0079] The curved portion 63 has a curved (arc-shaped) cross-sectional shape, connecting the engine compartment side end edge of the inclined portion 62 and the engine compartment side end edge of the inclined portion 64.

[0080] The inclined section 64 extends from the curved section 63 toward the passenger compartment side. The area of ​​the circular region enclosed by the passenger compartment side edge of the inclined section 64 is larger than the area of ​​the circular region enclosed by the engine compartment side edge of the inclined section 64 connected to the curved section 63.

[0081] The curved portion 65 has a curved cross-sectional shape, connecting the end edge of the inclined portion 64 on the occupant compartment side to the elastic ring 55 of the mounting portion 51. The inner flange 56b of the rigid ring 56 of the mounting portion 51 is embedded in the curved portion 65.

[0082] Thus, the inclined portion 64 is positioned radially outward from the inclined portion 62. Therefore, the inclined portion 64 is the outer inclined portion with respect to the inclined portion 62, and the inclined portion 62 is the inner inclined portion with respect to the inclined portion 64.

[0083] In the following description, the thickness of the various portions of the sealing portion 50 refers to the thickness of the sealing portion 50 when no elastic deformation has occurred.

[0084] like Figure 2 As shown, the curved portion 63 has an arc-shaped cross-section and a uniform thickness t8. The thickness of the curved portion 65 is not uniform; at the position adjacent to the inclined portion 64, the curved portion 65 has the minimum thickness t9. The thickness of the curved portion 61 is also not uniform; at the position adjacent to the inclined portion 62, the curved portion 61 has the minimum thickness t10.

[0085] The outer inclined portion 64 has an outer thin-walled portion 70, an outer thickness-varying portion 71, an outer thick-walled portion 72, and an outer thickness-varying portion 73. The outer thin-walled portion 70 is connected to the curved portion 63 and has the same uniform thickness t8 as the curved portion 63. The outer thick-walled portion 72 has a uniform thickness t11 that is greater than the thickness t8 of both the curved portion 63 and the outer thin-walled portion 70. The outer thickness-varying portion (first outer thickness-varying portion) 71 connects the outer thin-walled portion 70 and the outer thick-walled portion 72, and its thickness increases sharply and linearly from the outer thin-walled portion 70 toward the outer thick-walled portion 72.

[0086] The outer thickness variation portion (second outer thickness variation portion) 73 extends from the outer thick wall portion 72 in the opposite direction to the outer thickness variation portion 71, connecting the outer thick wall portion 72 and the curved portion 65. The thickness of the outer thickness variation portion 73 gradually and linearly increases from the curved portion 65 towards the outer thick wall portion 72. In other words, the outer thickness variation portion 73 has a thickness that linearly decreases from the outer thick wall portion 72 towards the curved portion 65. Therefore, the end of the outer thickness variation portion 73 on the curved portion 65 side locally has the same thickness as the minimum thickness t9 of the curved portion 65. The thickness t11 of the outer thick wall portion 72 is greater than the minimum thickness t9 of the curved portion 65.

[0087] One surface of the outer inclined portion 64 (the surface on the passenger compartment side) is a smooth frustum shape. However, the other surface of the outer inclined portion 64 (the surface on the engine compartment side) has a protruding portion due to the variation in thickness of the inclined portion 64. Protruding portions can be formed not only on the engine compartment side surface of the outer inclined portion 64, but also on the passenger compartment side surface of the outer inclined portion 64.

[0088] The inner inclined portion 62 has an inner thin-walled portion 75, an inner thickness-varying portion 76, an inner thick-walled portion 77, and an inner thickness-varying portion 78. The inner thin-walled portion 75 is connected to the curved portion 63 and has the same uniform thickness t8 as the curved portion 63. The inner thick-walled portion 77 has a uniform thickness t12 that is greater than the thickness t8 of both the curved portion 63 and the inner thin-walled portion 75. The inner thickness-varying portion (first inner thickness-varying portion) 76 connects the inner thin-walled portion 75 and the inner thick-walled portion 77, and its thickness increases sharply and linearly from the inner thin-walled portion 75 toward the inner thick-walled portion 77.

[0089] The inner thickness variation section (second inner thickness variation section) 78 extends from the inner thick wall section 77 in the opposite direction to the inner thickness variation section 76, connecting the inner thick wall section 77 and the curved section 61. The inner thickness variation section 78 has a thickness that increases sharply and linearly from the curved section 61 toward the inner thick wall section 77. In other words, the inner thickness variation section 78 has a thickness that decreases linearly from the inner thick wall section 77 toward the curved section 61. Therefore, the end of the inner thickness variation section 78 on the curved section 61 side locally has the same thickness as the minimum thickness t10 of the curved section 61.

[0090] One surface of the inner inclined portion 62 (the surface on the passenger compartment side) is a smooth frustum shape. However, the other surface of the inner inclined portion 62 (the surface on the engine compartment side) has a protruding portion due to the variation in the thickness of the inclined portion 62. The protruding portion can be formed not only on the engine compartment side surface of the inner inclined portion 62, but also on the passenger compartment side surface of the inner inclined portion 62.

[0091] In the second sealing section 50, the outer inclined portion 64 and the inner inclined portion 62 of the corrugated section 53 are provided with an outer thick-walled portion 72 and an inner thick-walled portion 77. These thick-walled portions 72 and 77 effectively suppress the transmission of noise from the engine compartment to the passenger compartment. On the other hand, the curved portion 63, the outer thin-walled portion 70, and the inner thin-walled portion 75 of the corrugated section 53 are easily deformable due to their small thickness, thus reducing the resistance, i.e., torque, exerted by the sealing section 50 on the rotating shaft 4. Especially in low-temperature environments, even if the elastomer forming the corrugated section 53 hardens, these thin portions are still easily deformable. Since the resistance exerted on the rotating shaft 4 is small, the noise generated by the sliding of the rotating shaft 4 and the sliding portion 54 is also reduced.

[0092] Preferably, the thickness t11 of the outer thick-walled portion 72 and the thickness t12 of the inner thick-walled portion 77 are at least 1.1 times the thickness t8 of the curved portion 63. In this case, the outer thick-walled portion 72 and the inner thick-walled portion 77 can effectively suppress noise transmitted from the engine compartment to the passenger compartment. In addition, since the curved portion 63 is thinner, the resistance, i.e., torque, given to the rotating shaft 4 by the sealing portion 50 can be reduced. More preferably, the thickness t11 of the outer thick-walled portion 72 and the thickness t12 of the inner thick-walled portion 77 are at least 1.3 times the thickness t8 of the curved portion 63.

[0093] Preferably, the length L8 of the outer thick-walled portion 72 is greater than 1 / 3.2 of the length L7 of the outer inclined portion 64, which has a frustum shape and includes the outer thin-walled portion 70, the first outer thickness variation portion 71, the outer thick-walled portion 72, and the second outer thickness variation portion 73. In this case, the outer thick-walled portion 72, which has a larger thickness in the frustum-shaped outer inclined portion 64, has a larger length L8, and therefore the outer inclined portion 64 has a larger weight. The outer inclined portion 64 can effectively suppress the transmission of engine compartment noise to the passenger compartment.

[0094] Furthermore, preferably, the length L6 of the inner thick-walled portion 77 is greater than 1 / 3.8 of the length L5 of the inner inclined portion 62, which has a frustum shape and includes the inner thin-walled portion 75, the first inner thickness variation portion 76, the inner thick-walled portion 77, and the second inner thickness variation portion 78. In this case, the length L6 of the inner thick-walled portion 77, which has a larger thickness in the frustum-shaped inner inclined portion 62, is larger, so the inner inclined portion 62 has a larger weight, and the inner inclined portion 62 can effectively suppress the transmission of engine compartment noise to the passenger compartment.

[0095] Furthermore, for the inner inclined portion 62, the curved portion 61 is the inner connecting portion connecting the cylindrical portion 52 and the inner inclined portion 62. The curved portion (inner connecting portion) 61 has a thickness smaller than the thickness t11 of the outer thick-walled portion 72 and the thickness t12 of the inner thick-walled portion 77. Therefore, the thinner curved portion 61 is easier to deform, which can further reduce the resistance, i.e., torque, given by the sealing portion 50 to the rotating shaft 4.

[0096] Preferably, the thickness t12 of the inner thick-walled portion 77 of the inclined portion 62 is more than 1.1 times the maximum thickness t13 of the curved portion (inner connecting portion) 61. In this case, the inner thick-walled portion 77 can effectively suppress the transmission of engine compartment noise to the passenger compartment. In addition, since the curved portion 61 is thinner, the resistance, i.e., torque, given by the sealing portion 50 to the rotating shaft 4 can be reduced.

[0097] Furthermore, for the outer inclined portion 64, the curved portion 65 is the outer connecting portion connecting the mounting portion 51 and the outer inclined portion 64. The minimum thickness t9 of the curved portion (outer connecting portion) 65 is less than the thickness t11 of the outer thick-walled portion 72 and the thickness t12 of the inner thick-walled portion 77. Therefore, the curved portion 65, with its smaller thickness, is easier to deform, which can further reduce the resistance, i.e., torque, given by the sealing portion 50 to the rotating shaft 4.

[0098] The outer inclined portion 64 and the inner inclined portion 62 have thickness variation portions 71, 73, 76, and 78 with gradually changing thickness. Therefore, stress concentration is less likely to occur in the outer inclined portion 64 and the inner inclined portion 62. Furthermore, as... Figure 5 As shown, when the corrugated part 53 is manufactured using molds 90 and 91, the thickness variation parts 71, 73, 76, and 78, whose thickness gradually changes, do not hinder the flow of elastomer in the cavity inside the molds 90 and 91. Therefore, the elastomer can easily spread throughout the mold inside the corrugated part 53.

[0099] like Figure 5 As shown, the corrugated portion 53 does not have undercuts that would prevent the corrugated portion 53 from separating from the molds 90 and 91 that form the corrugated portion 53 along the axial direction. Although the outer inclined portion 64 and the inner inclined portion 62 have thickness variation portions 71, 73, 76, and 78 with gradually changing thickness, when manufacturing the corrugated portion 53 using the molds 90 and 91, the corrugated portion 53 can be easily removed from the molds 90 and 91 by separating the molds 90 and 91 along the axial direction.

[0100] In particular, the outer thick-walled portion 72 of the outer inclined portion 64 protrudes radially outward (to the engine compartment side) relative to the frustum shape of the outer inclined portion 64, but the outer peripheral surface (engine compartment side surface) of the second outer thickness variation portion 73 of the outer inclined portion 64 is approximately cylindrical, thus facilitating the separation of the mold 90 from the corrugated portion 53. Furthermore, the inner thick-walled portion 77 of the inner inclined portion 62 protrudes radially inward (to the engine compartment side) relative to the frustum shape of the inner inclined portion 62, but the inner peripheral surface (engine compartment side surface) of the second inner thickness variation portion 78 of the inner inclined portion 62 is approximately cylindrical, thus facilitating the separation of the mold 90 from the corrugated portion 53.

[0101] In summary, the sealing device 1 of this embodiment has two sealing parts 10 and 50 with similar structures. By having a dual structure with sealing parts 10 and 50, the function of suppressing the transmission of sound from the engine compartment side space E to the passenger compartment side space P can be further improved, and the function of suppressing foreign objects from the engine compartment side space E into the passenger compartment side space P can be further improved.

[0102] like Figure 2As shown, when the sealing portions 10 and 50 are not elastically deformed, the curved portion 61 of the second sealing portion 50 overlaps axially with the curved portion 21 of the first sealing portion 10, and the inclined portion 62 overlaps axially with the inclined portion 22. At this time, the curved portion 63 overlaps axially with the curved portion 23, the inclined portion 64 overlaps axially with the inclined portion 24, and the curved portion 65 overlaps axially with the curved portion 25. In the second sealing portion 50, the portion formed by the inclined portion 62, the curved portion 63, and the inclined portion 64 protrudes towards the engine compartment side. Similarly, in the first sealing portion 10, the portion formed by the inclined portion 22, the curved portion 23, and the inclined portion 24 also protrudes towards the engine compartment side.

[0103] In a dual structure having such sealing parts 10 and 50, such as Figure 3 As shown, when the rotating shaft 4 is tilted and eccentric relative to the hole 2A, it is desirable that the corrugated portion 13 of the sealing portion 10 and the corrugated portion 53 of the sealing portion 50 do not collide with each other. In the illustrated embodiment, the corrugated portion 13 and the corrugated portion 53 are sufficiently far apart in the axial direction, but in the case where the corrugated portion 13 and the corrugated portion 53 are close to each other in the axial direction, it is particularly desirable that the thick-walled portions 32 and 37 of the corrugated portion 13 do not collide with the thick-walled portions 72 and 77 of the corrugated portion 53.

[0104] Therefore, the outer thick-walled portion 32 of the outer inclined portion 24 of the first sealing portion 10 protrudes toward the opposite side (passenger compartment side) of the corrugated portion 53 of the second sealing portion 50, relative to the frustum shape presented by the outer inclined portion 24, and the surface of the outer inclined portion 24 of the first sealing portion 10 opposite to the corrugated portion 53 of the second sealing portion 50 (the surface on the engine compartment side) has a smooth frustum shape. Furthermore, the inner thick-walled portion 37 of the inner inclined portion 22 of the first sealing portion 10 protrudes toward the opposite side (passenger compartment side) of the corrugated portion 53 of the second sealing portion 50, relative to the frustum shape presented by the inner inclined portion 22, and the surface of the inner inclined portion 22 of the first sealing portion 10 opposite to the corrugated portion 53 of the second sealing portion 50 (the surface on the engine compartment side) has a smooth frustum shape.

[0105] On the other hand, the outer thick wall portion 72 of the outer inclined portion 64 of the second sealing portion 50 protrudes toward the opposite side (engine compartment side) of the corrugated portion 13 of the first sealing portion 10, relative to the frustum shape presented by the outer inclined portion 64, and the surface of the outer inclined portion 64 of the second sealing portion 50 opposite to the corrugated portion 13 of the first sealing portion 10 (the surface on the passenger compartment side) has a smooth frustum shape. Furthermore, the inner thick wall portion 77 of the inner inclined portion 62 of the second sealing portion 50 protrudes toward the opposite side (engine compartment side) of the corrugated portion 13 of the first sealing portion 10, relative to the frustum shape presented by the inner inclined portion 62, and the surface of the inner inclined portion 62 of the second sealing portion 50 opposite to the corrugated portion 13 of the first sealing portion 10 (the surface on the passenger compartment side) has a smooth frustum shape.

[0106] Therefore, even when the axial distance between the corrugated portion 13 of the first sealing portion 10 and the corrugated portion 53 of the second sealing portion 50 is small, the outer inclined portion 24 (especially the outer thick-walled portion 32) of the first sealing portion 10 is less likely to collide with the outer inclined portion 64 (especially the outer thick-walled portion 72) of the second sealing portion 50, and the inner inclined portion 22 (especially the inner thick-walled portion 37) of the first sealing portion 10 is less likely to collide with the inner inclined portion 62 (especially the inner thick-walled portion 77) of the second sealing portion 50.

[0107] Figure 6 This is a partial cross-sectional perspective view showing a sealing device 1A according to another embodiment of the present invention. Figure 6 The cross-section shown is a plane that includes the central axis Ax.

[0108] The sealing device 1A has a composite structure with two sealing parts 10A and 50A (a first sealing part 10A and a second sealing part 50A). Each of the sealing parts 10A and 50A is an annular component centered on the central axis Ax. Each of the sealing parts 10A and 50A can be considered as a sealing device (steering dust seal).

[0109] The first sealing portion (first sealing device) 10A is the same as the sealing portion 10, and includes: an annular mounting portion 11; a cylindrical portion 12 disposed radially inside the mounting portion 11; and a corrugated portion 113 that connects the mounting portion 11 and the cylindrical portion 12. The cylindrical portion 12 and the corrugated portion 113 are made of the same elastic body as the elastic ring 15 of the mounting portion 11. Preferably, the elastic ring 15, the cylindrical portion 12, and the corrugated portion 113 are integrally formed. Furthermore, the sealing portion 10A has a sliding portion 14 disposed radially inside the cylindrical portion 12 and slidably contacting the outer peripheral surface of the rotating shaft 4. The mounting portion 11, the cylindrical portion 12, and the sliding portion 14 are the same as the corresponding portions in the sealing portion 10.

[0110] However, the corrugated portion 113 has more inclined and curved portions than the corrugated portion 13. That is, the corrugated portion 113 has an inclined portion 20, a curved portion 121, an inclined portion 122, a curved portion 123, an inclined portion 124, a curved portion 125, an inclined portion 126, a curved portion 127, an inclined portion 128, a curved portion 129, and an inclined portion 130. The inclined portions 20, 122, 124, 126, 128, and 130 are in the shape of a frustum. However, the inclination direction of the inclined portions 20, 124, and 128 is opposite to the inclination direction of the inclined portions 122, 126, and 130.

[0111] Inclined part 20 and Figures 1 to 3 The inclined portion 20 is the same, and the curved portion 121 is corresponding. Figures 1 to 3 The curved portion 21. The inclined portion 122 corresponds to... Figures 1 to 3 The inclined portion 22 and the curved portion 123 correspond to Figures 1 to 3 The curved portion 23. The inclined portion 124 corresponds to... Figures 1 to 3 The inclined part 24.

[0112] The curved portion 125 has a curved (arc-shaped) cross-sectional shape, connecting the end edge of the inclined portion 124 on the passenger compartment side to the end edge of the inclined portion 126 on the passenger compartment side.

[0113] The inclined portion 126 extends from the curved portion 125 toward the engine compartment side. The area of ​​the circular region enclosed by the engine compartment side edge of the inclined portion 126 is larger than the area of ​​the circular region enclosed by the passenger compartment side edge of the inclined portion 126 connected to the curved portion 125.

[0114] The curved portion 127 has a curved (arc-shaped) cross-sectional shape, connecting the engine compartment side end edge of the inclined portion 126 to the engine compartment side end edge of the inclined portion 128.

[0115] The inclined section 128 extends from the curved section 127 toward the passenger compartment side. The area of ​​the circular region enclosed by the passenger compartment side edge of the inclined section 128 is larger than the area of ​​the circular region enclosed by the engine compartment side edge of the inclined section 128 connected to the curved section 127.

[0116] The curved portion 129 has a curved (arc-shaped) cross-sectional shape, connecting the end edge of the inclined portion 128 on the passenger compartment side to the end edge of the inclined portion 130 on the passenger compartment side.

[0117] The inclined portion 130 extends from the curved portion 129 toward the engine compartment side and is connected to the elastic ring 15 of the mounting portion 11. The area of ​​the circular region enclosed by the engine compartment side end edge of the inclined portion 130 connected to the elastic ring 15 is larger than the area of ​​the circular region enclosed by the passenger compartment side end edge of the inclined portion 130 connected to the curved portion 129.

[0118] Inclined portion 122 is disposed radially outward of inclined portion 20, inclined portion 124 is disposed radially outward of inclined portion 122, and inclined portion 126 is disposed radially outward of inclined portion 124. Inclined portion 128 is disposed radially outward of inclined portion 126, and inclined portion 130 is disposed radially outward of inclined portion 128. Therefore, with respect to inclined portion 124, inclined portion 122 is an inner inclined portion, and with respect to inclined portion 122, inclined portion 124 is an outer inclined portion. With respect to inclined portion 126, inclined portion 124 is an inner inclined portion, and with respect to inclined portion 124, inclined portion 126 is an outer inclined portion. With respect to inclined portion 128, inclined portion 126 is an inner inclined portion, and with respect to inclined portion 126, inclined portion 128 is an outer inclined portion.

[0119] The thickness of the curved portions 121, 123, 125, 127, and 129 is relatively small. The curved portions 123, 125, 127, and 129 each have an arc-shaped cross-section and a uniform thickness. The thickness of the curved portion 121 is not uniform; it has the smallest thickness at the position adjacent to the inclined portion 122.

[0120] Although Figure 6 Reference numerals are not shown in the accompanying drawings, but the inclined portion 122 and... Figures 1 to 3 Similarly, the inclined portion 22 has portions corresponding to the inner thin-walled portion 35, the inner thickness-varying portion 36, the inner thick-walled portion 37, and the inner thickness-varying portion 38. One surface of the inclined portion 122 (the surface on the engine compartment side) is a smooth frustum shape. However, the other surface of the inclined portion 122 (the surface on the passenger compartment side) has a protruding portion due to the variation in the thickness of the inclined portion 122. The protruding portion can be formed not only on the passenger compartment side surface of the inclined portion 122 but also on the engine compartment side surface of the inclined portion 122.

[0121] Inclined part 124 and Figures 1 to 3 Similarly, the inclined portion 24 has portions corresponding to the outer thin-walled portion 30, the outer thickness-varying portion 31, the outer thick-walled portion 32, the outer thickness-varying portion 33, and the outer thin-walled portion 34. One surface of the inclined portion 124 (the surface on the engine compartment side) is a smooth frustum shape. However, the other surface of the inclined portion 124 (the surface on the passenger compartment side) has a protruding portion due to the variation in the thickness of the inclined portion 124. The protruding portion can be formed not only on the passenger compartment side surface of the inclined portion 124 but also on the engine compartment side surface of the inclined portion 124.

[0122] Inclined part 126 also with Figures 1 to 3 Similarly, the inclined portion (inner inclined portion) 22 also has portions corresponding to the inner thin-walled portion 35, the inner thickness-varying portion 36, the inner thick-walled portion 37, and the inner thickness-varying portion 38. One surface of the inclined portion 126 (the surface on the engine compartment side) is a smooth frustum shape. However, the other surface of the inclined portion 126 (the surface on the passenger compartment side) has a protruding portion due to the variation in the thickness of the inclined portion 126. The protruding portion can be formed not only on the passenger compartment side surface of the inclined portion 126 but also on the engine compartment side surface of the inclined portion 126.

[0123] Inclined part 128 is also with Figures 1 to 3Similarly, the inclined portion (outer inclined portion) 24 has portions corresponding to the outer thin-walled portion 30, the outer thickness-varying portion 31, the outer thick-walled portion 32, the outer thickness-varying portion 33, and the outer thin-walled portion 34. One surface of the inclined portion 128 (the surface on the engine compartment side) is a smooth frustum shape. However, the other surface of the inclined portion 128 (the surface on the passenger compartment side) has a protruding portion due to the variation in the thickness of the inclined portion 128. The protruding portion can be formed not only on the passenger compartment side surface of the inclined portion 128 but also on the engine compartment side surface of the inclined portion 128.

[0124] In the first sealing section 10A, the inclined portions 122, 124, 126, and 128 of the corrugated section 113 are provided with thick-walled portions, which effectively suppress the transmission of noise from the engine compartment to the passenger compartment. On the other hand, the thin-walled portions 123, 125, and 127 of the corrugated section 113 and the inclined portions 122, 124, 126, and 128 are easily deformable due to their small thickness, thus reducing the resistance, i.e., torque, exerted by the sealing section 10A on the rotating shaft 4. Especially in low-temperature environments, even if the elastomer forming the corrugated section 113 hardens, these thin portions are easily deformable. Since the resistance exerted on the rotating shaft 4 is small, the noise generated by the sliding of the rotating shaft 4 and the sliding portion 14 is also reduced.

[0125] Preferably, the thickness of the thick-walled portions of the inclined portions 122, 124, 126, and 128 is at least 1.1 times the thickness of the curved portions 123, 125, and 127. In this case, the thick-walled portions of the inclined portions 122, 124, 126, and 128 can effectively suppress the transmission of engine compartment noise to the passenger compartment. Furthermore, since the curved portions 123, 125, and 127 are relatively thin, the resistance, i.e., torque, exerted by the sealing portion 10A on the rotating shaft 4 can be reduced. More preferably, the thickness of the thick-walled portions of the inclined portions 122, 124, 126, and 128 is at least 1.3 times the thickness of the curved portions 123, 125, and 127.

[0126] Preferably, the length of the thick-walled portion in each of the inclined portions 124 and 128 is greater than 1 / 10.6 of the length of the inclined portion having a frustum shape. In this case, since the thick-walled portion with greater thickness in the inclined portions 124 and 128 having a frustum shape is longer, the inclined portions 124 and 128 are heavier, thereby the inclined portions 124 and 128 can effectively suppress the transmission of engine compartment noise to the passenger compartment.

[0127] Furthermore, preferably, the length of the thick-walled portion in each of the inclined portions 122 and 126 is greater than 1 / 5.3 of the length of the inclined portion having a frustum shape. In this case, since the thick-walled portion with greater thickness in the inclined portions 122 and 126 having a frustum shape is longer, the inclined portions 122 and 126 are heavier, thereby effectively suppressing the transmission of engine compartment noise to the passenger compartment.

[0128] Furthermore, for the inclined portion 122, the curved portion 121 is the inner connecting portion connecting the cylindrical portion 12 and the inclined portion 122. The thickness of the curved portion (inner connecting portion) 121 is less than the thickness of the thick-walled portions in the inclined portions 122, 124, 126, and 128. Therefore, the thinner curved portion 121 is easier to deform, which can further reduce the resistance, i.e., torque, given to the rotating shaft 4 by the sealing portion 10A.

[0129] Furthermore, for the inclined portion 128, the curved portion 129 and the inclined portion 130 are the outer connecting portions connecting the mounting portion 11 and the inclined portion 128. The thickness of the curved portion (outer connecting portion) 129 and the thickness of the inclined portion (outer connecting portion) 130 are less than the thickness of the thick-walled portions in the inclined portions 122, 124, 126, and 128. Therefore, the thinner curved portion 129 and the inclined portion 130 are easier to deform, which can further reduce the resistance, i.e., the torque, given to the rotating shaft 4 by the sealing portion 10A.

[0130] Preferably, the thickness of the thick wall portion of the inclined portion 128 is at least 1.1 times the thickness of the curved portion (outer connecting portion) 129 and the inclined portion (outer connecting portion) 130. In this case, the thick wall portion of the inclined portion 128 can effectively suppress the transmission of engine compartment noise to the passenger compartment. On the other hand, since the thickness of the curved portion (outer connecting portion) 129 and the inclined portion (outer connecting portion) 130 is small, the resistance, i.e., the torque, given to the rotating shaft 4 by the sealing device 10A can be reduced.

[0131] The inclined portions 122, 124, 126, and 128 each have a thickness variation portion with a gradually changing thickness. Therefore, stress concentration is less likely to occur at the inclined portions 122, 124, 126, and 128. In addition, when manufacturing the corrugated portion 113 using a mold, the gradually changing thickness variation portion does not impede the flow of the elastomer in the mold cavity, making it easy for the elastomer to be distributed throughout the mold interior of the corrugated portion 113.

[0132] Although the inclined portions 122, 124, 126, and 128 each have a thickness variation portion with a gradually changing thickness, the corrugated portion 113 does not have an undercut that prevents the corrugated portion 113 from axially separating from the mold forming the corrugated portion 113. Therefore, when manufacturing the corrugated portion 113 using a mold, it is easy to remove the corrugated portion 113 from the mold.

[0133] The second sealing portion (second sealing device) 50A, like the sealing portion 50, has: an annular mounting portion 51; a cylindrical portion 52 disposed radially inside the mounting portion 51; and a corrugated portion 153 that connects the mounting portion 51 and the cylindrical portion 52. The cylindrical portion 52 and the corrugated portion 153 are made of the same elastic body as the elastic ring 55 of the mounting portion 51. Preferably, the elastic ring 55, the cylindrical portion 52, and the corrugated portion 153 are integrally formed. Further, the sealing portion 50A has a sliding portion 54 disposed radially inside the cylindrical portion 52 and slidably contacting the outer peripheral surface of the rotating shaft 4.

[0134] However, the corrugated portion 153 has more inclined and curved portions than the corrugated portion 53. Specifically, the corrugated portion 153 has inclined portions 162, curved portions 163, 164, 165, 166, 167, 168, and 169. The inclined portions 162, 164, 166, and 168 are frustum-shaped. However, the inclination direction of the inclined portions 162 and 166 is opposite to that of the inclined portions 164 and 168.

[0135] Bend 61 corresponds Figures 1 to 3 The curved portion 61 has a curved cross-sectional shape, connecting the end edge of the cylindrical portion 52 on the passenger compartment side to the end edge of the inclined portion 162 on the passenger compartment side.

[0136] Inclined part 162 corresponds Figures 1 to 3 The inclined portion 62 and the curved portion 163 correspond to Figures 1 to 3 The curved portion 63. The inclined portion 164 corresponds to... Figures 1 to 3 The inclined part 64.

[0137] The curved portion 165 has a curved (arc-shaped) cross-sectional shape, connecting the end edge of the inclined portion 164 on the passenger compartment side to the end edge of the inclined portion 166 on the passenger compartment side.

[0138] The inclined section 166 extends from the curved section 165 toward the engine compartment side. The area of ​​the circular region enclosed by the engine compartment side edge of the inclined section 166 is larger than the area of ​​the circular region enclosed by the passenger compartment side edge of the inclined section 166 connected to the curved section 165.

[0139] The curved portion 167 has a curved (arc-shaped) cross-sectional shape, connecting the engine compartment side end edge of the inclined portion 166 and the engine compartment side end edge of the inclined portion 168.

[0140] The inclined section 168 extends from the curved section 167 toward the passenger compartment side. The area of ​​the circular region enclosed by the passenger compartment side edge of the inclined section 168 is larger than the area of ​​the circular region enclosed by the engine compartment side edge of the inclined section 168 connected to the curved section 167.

[0141] The curved portion 169 has a curved cross-sectional shape, connecting the end edge of the inclined portion 168 on the occupant compartment side to the elastic ring 55 of the mounting portion 51. The inner flange 56b of the rigid ring 56 of the mounting portion 51 (see reference) Figure 1 It is embedded in the bend 169.

[0142] Thus, inclined portion 164 is disposed radially outward of inclined portion 162, inclined portion 166 is disposed radially outward of inclined portion 164, and inclined portion 168 is disposed radially outward of inclined portion 166. Therefore, with respect to inclined portion 162, inclined portion 164 is an outer inclined portion, and with respect to inclined portion 164, inclined portion 162 is an inner inclined portion. With respect to inclined portion 164, inclined portion 166 is an outer inclined portion, and with respect to inclined portion 166, inclined portion 164 is an inner inclined portion. With respect to inclined portion 166, inclined portion 168 is an outer inclined portion, and with respect to inclined portion 168, inclined portion 166 is an inner inclined portion.

[0143] In the second sealing portion 50A, the portion formed by the inclined portion 162, the curved portion 163, and the inclined portion 164 protrudes towards the engine compartment side. Similarly, in the first sealing portion 10A, the portion formed by the inclined portion 122, the curved portion 123, and the inclined portion 124 also protrudes towards the engine compartment side. In the second sealing portion 50A, the portion formed by the inclined portion 164, the curved portion 165, and the inclined portion 166 protrudes towards the passenger compartment side. Similarly, in the first sealing portion 10A, the portion formed by the inclined portion 124, the curved portion 125, and the inclined portion 126 also protrudes towards the passenger compartment side. In the second sealing portion 50A, the portion formed by the inclined portion 166, the curved portion 167, and the inclined portion 168 protrudes towards the engine compartment side. Similarly, in the first sealing portion 10A, the portion formed by the inclined portion 126, the curved portion 127, and the inclined portion 128 also protrudes towards the engine compartment side.

[0144] The thickness of the curved portions 61, 163, 165, 167, and 169 is relatively small. Curved portions 163, 165, and 167 each have an arc-shaped cross-section and a uniform thickness. The thickness of curved portion 169 is not uniform; it has the smallest thickness at the position adjacent to the inclined portion 168. The thickness of curved portion 61 is also not uniform; it has the smallest thickness at the position adjacent to the inclined portion 162.

[0145] Although Figure 6 Reference numerals are not shown in the accompanying drawings, but the inclined portion 162 and... Figures 1 to 3Similarly, the inclined portion (inner inclined portion) 62 also has portions corresponding to the inner thin-walled portion 75, the inner thickness-varying portion 76, the inner thick-walled portion 77, and the inner thickness-varying portion 78. One surface of the inclined portion 162 (the surface on the passenger compartment side) is a smooth frustum shape. However, the other surface of the inclined portion 162 (the surface on the engine compartment side) has a protruding portion due to the thickness variation of the inclined portion 162. The protruding portion can be formed not only on the surface on the engine compartment side of the inclined portion 162, but also on the surface on the passenger compartment side of the inclined portion 162.

[0146] Inclined part 164 and Figures 1 to 3 Similarly, the inclined portion (outer inclined portion) 64 has portions corresponding to the outer thin-walled portion 70, the outer thickness-varying portion 71, the outer thick-walled portion 72, and the outer thickness-varying portion 73. One surface of the inclined portion 164 (the surface on the passenger compartment side) is a smooth frustum shape. However, the other surface of the inclined portion 164 (the surface on the engine compartment side) has a protruding portion due to the thickness variation of the inclined portion 164. The protruding portion can be formed not only on the surface on the engine compartment side of the inclined portion 164, but also on the surface on the passenger compartment side of the inclined portion 164.

[0147] Inclined part 166 is also with Figures 1 to 3 Similarly, the inclined portion 62 has portions corresponding to the inner thin-walled portion 75, the inner thickness-varying portion 76, the inner thick-walled portion 77, and the inner thickness-varying portion 78. One surface of the inclined portion 166 (the surface on the passenger compartment side) is a smooth frustum shape. However, the other surface of the inclined portion 166 (the surface on the engine compartment side) has a protruding portion due to the thickness variation of the inclined portion 166. The protruding portion can be formed not only on the surface on the engine compartment side of the inclined portion 166, but also on the surface on the passenger compartment side of the inclined portion 166.

[0148] Inclined part 168 is also with Figures 1 to 3 Similarly, the inclined portion 64 has portions corresponding to the outer thin-walled portion 70, the outer thickness-varying portion 71, the outer thick-walled portion 72, and the outer thickness-varying portion 73. One surface of the inclined portion 168 (the surface on the passenger compartment side) is a smooth frustum shape. However, the other surface of the inclined portion 168 (the surface on the engine compartment side) has a protruding portion due to the thickness variation of the inclined portion 168. Protruding portions can be formed not only on the engine compartment side surface of the inclined portion 168 but also on the passenger compartment side surface of the inclined portion 168.

[0149] In the second sealing section 50A, the inclined portions 162, 164, 166, and 168 of the corrugated section 153 are provided with thick-walled portions, which effectively suppress the transmission of engine compartment noise to the passenger compartment. On the other hand, the thin-walled portions 163, 165, and 167 of the corrugated section 153 and the inclined portions 162, 164, 166, and 168 are thin and easily deformable, thus reducing the resistance, i.e., torque, exerted by the sealing section 50A on the rotating shaft 4. Especially in low-temperature environments, even if the elastomer forming the corrugated section 153 hardens, these thin portions are easily deformable. Since the resistance exerted on the rotating shaft 4 is small, the noise generated by the sliding of the rotating shaft 4 and the sliding portion 54 is also reduced.

[0150] Preferably, the thickness of the thick-walled portions of the inclined portions 162, 164, 166, and 168 is at least 1.1 times the thickness of the curved portions 163, 165, and 167. In this case, the thick-walled portions of the inclined portions 162, 164, 166, and 168 can effectively suppress the transmission of engine compartment noise to the passenger compartment. Furthermore, since the curved portions 163, 165, and 167 are relatively thin, the resistance, i.e., torque, exerted by the sealing portion 50A on the rotating shaft 4 can be reduced. More preferably, the thickness of the thick-walled portions of the inclined portions 162, 164, 166, and 168 is at least 1.3 times the thickness of the curved portions 163, 165, and 167.

[0151] Preferably, the length of the thick-walled portion of each of the inclined portions 164 and 168 is greater than 1 / 3.2 of the length of the inclined portion in the frustum shape. In this case, since the thicker thick-walled portion of the inclined portions 164 and 168 in the frustum shape has a larger length, the inclined portions 164 and 168 have a larger weight, thereby effectively suppressing the transmission of engine compartment noise to the passenger compartment.

[0152] Furthermore, preferably, the length of the thick-walled portion of each of the inclined portions 162 and 166 is greater than 1 / 3.8 of the length of the inclined portion having a frustum shape. In this case, since the thicker thick-walled portion of the inclined portions 162 and 166 having a frustum shape has a larger length, the inclined portions 162 and 166 have a larger weight, thereby effectively suppressing the transmission of engine compartment noise to the passenger compartment.

[0153] Furthermore, for the inclined portion 162, the curved portion 61 is the inner connecting portion connecting the cylindrical portion 52 and the inner inclined portion 162. The thickness of the curved portion (inner connecting portion) 61 is less than the thickness of the thick-walled portions of the inclined portions 162, 164, 166, and 168. Therefore, the thinner curved portion 61 is easier to deform, which can further reduce the resistance, i.e., torque, given to the rotating shaft 4 by the sealing portion 50A.

[0154] Preferably, the thickness of the thick-walled portion of the inclined portion 162 is more than 1.1 times the maximum thickness of the curved portion (inner connecting portion) 61. In this case, the thick-walled portion of the inclined portion 162 can effectively suppress the transmission of engine compartment noise to the passenger compartment. In addition, since the curved portion 61 is relatively thin, the resistance, i.e., torque, given to the rotating shaft 4 by the sealing portion 10A can be reduced.

[0155] Furthermore, for the inclined portion 168, the curved portion 169 is the outer connecting portion connecting the mounting portion 51 and the outer inclined portion 168. The thickness of the curved portion (outer connecting portion) 169 is less than the thickness of the thick-walled portions of the inclined portions 162, 164, 166, and 168. Therefore, the thinner curved portion 169 is easier to deform, which can further reduce the resistance, i.e., torque, given to the rotating shaft 4 by the sealing portion 50A.

[0156] The inclined portions 162, 164, 166, and 168 each have a thickness variation portion with a gradually changing thickness. Therefore, stress concentration is less likely to occur at the inclined portions 162, 164, 166, and 168. In addition, when manufacturing the corrugated portion 153 using a mold, the gradually changing thickness variation portion does not impede the flow of the elastomer in the mold cavity, making it easy for the elastomer to be distributed throughout the mold interior of the corrugated portion 153.

[0157] Although the inclined portions 162, 164, 166, and 168 each have a thickness variation portion with a gradually changing thickness, the corrugated portion 153 does not have an undercut that prevents the corrugated portion 153 from axially separating from the mold forming the corrugated portion 153. Therefore, when manufacturing the corrugated portion 153 using a mold, it is easy to remove the corrugated portion 153 from the mold.

[0158] In summary, the sealing device 1A in this embodiment has two sealing parts 10A and 50A with similar structures. By having a dual structure with sealing parts 10A and 50A, the function of suppressing sound transmission from the engine compartment side space E to the passenger compartment side space P can be further improved, and the function of suppressing foreign objects from entering the passenger compartment side space P from the engine compartment side space E can be further improved.

[0159] The number of inclined and curved portions in each corrugated part can also be greater. The number of inclined and curved portions in the corrugated part of the first sealing part can also differ from the number of inclined and curved portions in the corrugated part of the second sealing part.

[0160] When the sealing portions 10A and 50A are not elastically deformed, the bent portion 61 of the second sealing portion 50A overlaps axially with the bent portion 121 of the first sealing portion 10A, and the inclined portion 162 overlaps axially with the inclined portion 122. At this time, the bent portion 163 overlaps axially with the bent portion 123, and the inclined portion 164 overlaps axially with the inclined portion 124. The bent portion 165 overlaps axially with the bent portion 125, and the inclined portion 166 overlaps axially with the inclined portion 126. The bent portion 167 overlaps axially with the bent portion 127, the inclined portion 168 overlaps axially with the inclined portion 128, and the bent portion 169 overlaps axially with the bent portion 129.

[0161] In this dual structure with sealing portions 10A and 50A, when the rotating shaft 4 is tilted and eccentric relative to the hole 2A, it is desirable that the corrugated portion 113 of sealing portion 10A and the corrugated portion 153 of sealing portion 50A will not collide with each other. In the illustrated embodiment, the corrugated portion 113 and the corrugated portion 153 are sufficiently far apart in the axial direction, but in the configuration where the corrugated portion 113 and the corrugated portion 153 are close to each other in the axial direction, it is particularly desirable that the thick-walled portion of the corrugated portion 113 will not collide with the thick-walled portion of the corrugated portion 153.

[0162] Therefore, the thick-walled portion of each of the inclined portions 122, 124, 126, and 128 of the first sealing portion 10A protrudes toward the opposite side (passenger compartment side) of the corrugated portion 53 of the second sealing portion 50 relative to the frustum shape presented by the inclined portion, and the surface of each of the inclined portions 122, 124, 126, and 128 opposite to the corrugated portion 53 of the second sealing portion 50A (the surface on the engine compartment side) has a smooth frustum shape.

[0163] On the other hand, the thick-walled portion of each of the inclined portions 162, 164, 166, and 168 of the second sealing portion 50A protrudes toward the opposite side (engine compartment side) of the corrugated portion 113 of the first sealing portion 10A, relative to the frustum shape presented by the inclined portion, and the surface of each of the inclined portions 162, 164, 166, and 168 opposite to the corrugated portion 113 of the first sealing portion 10A (passenger compartment side) has a smooth frustum shape.

[0164] Therefore, even when the axial distance between the corrugated portion 113 of the first sealing portion 10A and the corrugated portion 153 of the second sealing portion 50A is small, the inclined portions 122, 124, 126, 128 (especially the thick-walled portions) of the first sealing portion 10A are not likely to collide with the inclined portions 162, 164, 166, 168 (especially the thick-walled portions) of the second sealing portion 50A.

[0165] The present invention has been illustrated and described above with reference to preferred embodiments. However, those skilled in the art should understand that various changes in form and detail may be made without departing from the scope of the invention as set forth in the claims. Such changes, alterations, and modifications should all be included within the scope of the present invention.

[0166] For example, a known sound-insulating ring, as disclosed in Japanese Patent Application Publication No. 2016-20721 or Japanese Patent Application Publication No. 2019-7552, can also be provided around the rotating shaft 4.

[0167] In the above embodiment, the sealing device 1 is a steering dust seal, but the present invention is not limited to steering dust seals, and can also be applied to a sealing device that seals around a rotating shaft that may have large eccentricity while attenuating noise.

[0168] The methods of the present invention are also described in the following numbered entries.

[0169] Item 1. A sealing device for sealing a gap between an outer support member and a rotating shaft, the rotating shaft being disposed inside a hole provided in the outer support member, the sealing device comprising: An annular mounting portion is installed in the hole of the outer support member; A cylindrical portion is disposed radially inside the mounting portion; A sliding portion is disposed radially inside the cylindrical portion and slidably contacts the outer peripheral surface of the rotating shaft; and The corrugated portion, located between the mounting portion and the cylindrical portion, is made of an elastic body. The corrugated portion has: an outer inclined portion having a frustum shape; an inner inclined portion having a frustum shape and inclined in the opposite direction to the outer inclined portion; and a curved portion having a curved cross-sectional shape and connecting the outer inclined portion and the inner inclined portion. The outer inclined portion has an outer thick-walled portion, the thickness of which is greater than the thickness of the curved portion. The inner inclined portion has an inner thick wall portion, the thickness of which is greater than the thickness of the curved portion.

[0170] Item 2. The sealing device according to Item 1, wherein, The outer inclined portion further comprises: an outer thin-walled portion connected to the curved portion and having the same thickness as the curved portion; a first outer thickness variation portion connecting the outer thin-walled portion and the outer thick-walled portion, the thickness of which increases linearly from the outer thin-walled portion toward the outer thick-walled portion; and a second outer thickness variation portion located between the outer thick-walled portion and the mounting portion, the thickness of which decreases linearly from the outer thick-walled portion, wherein the thickness of the outer thick-walled portion is uniform. The inner inclined portion further comprises: an inner thin-walled portion connected to the curved portion and having the same thickness as the curved portion; a first inner thickness variation portion connecting the inner thin-walled portion and the inner thick-walled portion and having a thickness that increases linearly from the inner thin-walled portion toward the inner thick-walled portion; and a second inner thickness variation portion located between the inner thick-walled portion and the cylindrical portion and having a thickness that decreases linearly from the inner thick-walled portion, wherein the thickness of the inner thick-walled portion is uniform.

[0171] Because the outer and inner inclined portions have gradually changing thicknesses, stress concentration is less likely to occur. Furthermore, for example, when manufacturing corrugated sections using a mold, the gradually changing thicknesses do not impede the flow of the elastomer within the mold, allowing the elastomer to easily spread throughout the interior of the mold used to form the corrugated section.

[0172] Item 3. The sealing device according to Item 2, wherein, The corrugated portion does not have an undercut that prevents the corrugated portion from separating from the mold forming the corrugated portion in the axial direction.

[0173] Although the outer and inner inclined portions have sections with gradually changing thickness, the corrugated portions are easy to remove from the mold when manufacturing the corrugated portions using a mold.

[0174] Item 4. The sealing device according to Item 3, wherein, The outer thick-walled portion of the outer inclined portion protrudes radially outward relative to the frustum shape presented by the outer inclined portion. The outer peripheral surface of the second outer thickness variation portion of the outer inclined portion is approximately cylindrical. The inner thick-walled portion of the inner inclined portion protrudes radially inward relative to the frustum shape presented by the inner inclined portion. The inner circumferential surface of the second inner thickness variation portion of the inner inclined portion is approximately cylindrical.

[0175] With the above structure, the corrugated portion does not have an undercut that would prevent the corrugated portion from being removed from the mold in which it is formed.

[0176] Item 5. The sealing device according to Item 3, wherein, The outer thick-walled portion of the outer inclined portion protrudes radially inward relative to the frustum shape presented by the outer inclined portion. The inner circumferential surface of the first outer thickness variation portion of the outer inclined portion is approximately cylindrical. The inner thick-walled portion of the inner inclined portion protrudes radially outward relative to the frustum shape presented by the inner inclined portion. The outer peripheral surface of the first inner thickness variation portion of the inner inclined portion is approximately cylindrical.

[0177] With the above structure, the corrugated portion does not have an undercut that would prevent the corrugated portion from being removed from the mold in which it is formed.

[0178] Item 6. The sealing device according to any one of items 2 to 5, wherein, The length of the outer thick-walled portion is greater than 1 / 10.6 of the length of the outer inclined portion, which includes the outer thin-walled portion, the first outer thickness variation portion, the outer thick-walled portion, and the second outer thickness variation portion and has a frustum shape. The length of the inner thick-walled portion is greater than 1 / 5.3 of the length of the inner inclined portion, which includes the inner thin-walled portion, the first inner thickness variation portion, the inner thick-walled portion, and the second inner thickness variation portion and has a frustum shape.

[0179] In this configuration, because the outer thick-walled portion, which has a greater thickness in the frustum-shaped outer inclined portion, has a greater length, the outer inclined portion has a greater weight, thus effectively suppressing the transmission of noise from the engine compartment to the passenger compartment. Similarly, because the inner thick-walled portion, which has a greater thickness in the frustum-shaped inner inclined portion, has a greater length, the inner inclined portion has a greater weight, thus effectively suppressing the transmission of noise from the engine compartment to the passenger compartment.

[0180] Item 7. The sealing device according to any one of items 2 to 6, wherein, The thickness of the outer thick-walled portion is more than 1.1 times the thickness of the curved portion. The thickness of the inner thick-walled portion is more than 1.1 times the thickness of the curved portion.

[0181] Since the thickness of the outer thick-walled portion and the inner thick-walled portion are more than 1.1 times the thickness of the curved portion, the outer thick-walled portion and the inner thick-walled portion can effectively suppress the transmission of noise from the engine compartment to the passenger compartment. On the other hand, since the thickness of the curved portion is less than 1 / 1.1 of the thickness of the outer thick-walled portion and the inner thick-walled portion, the resistance, i.e., the torque, applied to the rotating shaft by the sealing device can be reduced.

[0182] Item 8. The sealing device according to any one of items 1 to 7, wherein, The sealing device also has an inner connecting portion, which connects the cylindrical portion and the inner inclined portion of the corrugated portion. The thickness of the inner connecting portion is less than the thickness of the outer thick-walled portion and the thickness of the inner thick-walled portion.

[0183] In this case, since the inner connecting part with a smaller thickness is prone to deformation, the resistance, i.e. torque, applied to the rotating shaft by the sealing device can be further reduced.

[0184] Item 9. The sealing device according to Item 8, wherein, The thickness of the inner thick-walled portion is more than 1.1 times the thickness of the inner connecting portion.

[0185] Since the thickness of the inner thick-walled portion is more than 1.1 times the thickness of the inner connecting portion, the inner thick-walled portion can effectively suppress the transmission of noise from the engine compartment to the passenger compartment. On the other hand, since the thickness of the inner connecting portion is less than 1 / 1.1 of the thickness of the inner thick-walled portion, the resistance, i.e., the torque, applied to the rotating shaft by the sealing device can be reduced.

[0186] Item 10. The sealing device according to any one of items 1 to 9, wherein, The sealing device also has an outer connecting portion, which connects the mounting portion and the outer inclined portion of the corrugated portion. The thickness of the outer connecting portion is less than the thickness of the outer thick-walled portion and the thickness of the inner thick-walled portion.

[0187] In this case, since the thinner outer connecting part is prone to deformation, the resistance, i.e. torque, applied to the rotating shaft by the sealing device can be further reduced.

[0188] Item 11. The sealing device according to Item 10, wherein, The thickness of the outer thick-walled portion is more than 1.1 times the thickness of the outer connecting portion.

[0189] Since the thickness of the outer thick-walled portion is more than 1.1 times the thickness of the outer connecting portion, the outer thick-walled portion can effectively suppress the transmission of noise from the engine compartment to the passenger compartment. On the other hand, since the thickness of the outer connecting portion is less than 1 / 1.1 of the thickness of the outer thick-walled portion, the resistance, i.e., the torque, applied to the rotating shaft by the sealing device can be reduced.

[0190] Item 12. The sealing device according to any one of items 1 to 11, wherein the sealing device comprises a first sealing portion and a second sealing portion, wherein, Each of the first sealing portion and the second sealing portion has: An annular mounting portion is installed in the hole of the outer support member; A cylindrical portion is disposed radially inside the mounting portion; A sliding portion is disposed radially inside the cylindrical portion and slidably contacts the outer peripheral surface of the rotating shaft; and The corrugated portion, located between the mounting portion and the cylindrical portion, is made of an elastic body. The corrugated portion has: an outer inclined portion having a frustum shape; an inner inclined portion having a frustum shape and inclined in the opposite direction to the outer inclined portion; and a curved portion having a curved cross-sectional shape and connecting the outer inclined portion and the inner inclined portion. The outer inclined portion has an outer thick-walled portion with a thickness greater than that of the curved portion. The inner inclined portion has an inner thick-walled portion with a thickness greater than that of the curved portion. The curved portion, the outer inclined portion, and the inner inclined portion of the first sealing portion overlap, in the axial direction, the curved portion, the outer inclined portion, and the inner inclined portion of the second sealing portion, respectively. The outer thick-walled portion of the outer inclined portion of the first sealing portion protrudes toward the opposite side of the corrugated portion of the second sealing portion relative to the frustum shape presented by the outer inclined portion. The outer inclined portion of the first sealing portion has a smooth frustum shape on the surface opposite to the corrugated portion of the second sealing portion. The inner thick-walled portion of the inner inclined portion of the first sealing portion protrudes toward the opposite side of the corrugated portion of the second sealing portion, relative to the frustum shape presented by the inner inclined portion. The inner inclined portion of the first sealing portion has a smooth frustum shape on the surface opposite to the corrugated portion of the second sealing portion. The outer thick-walled portion of the outer inclined portion of the second sealing portion protrudes toward the opposite side of the corrugated portion of the first sealing portion relative to the frustum shape of the outer inclined portion. The outer inclined portion of the second sealing portion has a smooth frustum shape on the surface opposite to the corrugated portion of the first sealing portion. The inner thick-walled portion of the inner inclined portion of the second sealing portion protrudes towards the opposite side of the corrugated portion of the first sealing portion, relative to the frustum shape presented by the inner inclined portion. The inner inclined portion of the second sealing portion has a smooth frustum shape on the surface opposite to the corrugated portion of the first sealing portion.

[0191] In this configuration, the curved portion, the outer inclined portion, and the inner inclined portion of the first sealing portion overlap axially with the curved portion, the outer inclined portion, and the inner inclined portion of the second sealing portion, respectively. The inclined portions have thick walls. However, since the shapes of the outer and inner inclined portions of the first and second sealing portions are as described above, even when the axial distance between the corrugated portions of the first and second sealing portions is small, the outer inclined portion of the first sealing portion is less likely to collide with the outer inclined portion of the second sealing portion, and the inner inclined portion of the first sealing portion is also less likely to collide with the inner inclined portion of the second sealing portion.

[0192] Explanation of reference numerals in the attached figures E Engine compartment side space P crew compartment side space 1.1A Sealing device (steering dust seal) 2. Outer supporting components 2A hole 4. Rotation shaft (steering shaft) 10, 10A First sealing part (first sealing device) 50, 50A Second sealing part (second sealing device) 11,51 Installation Department 12, 52 Cylindrical section 13, 53, 113, 153 Corrugated sections 14, 54 Sliding parts 20 Inclined section 21, 61, 121 Bending section (inner connection section) 22, 62 Inclined section (inner inclined section) 23, 63, 123, 125, 127, 163, 165, 167 Bends 24, 64 Inclined section (outer inclined section) 122, 124, 126, 162, 164, 166 Inclined section (inner inclined section) 124, 126, 128, 164, 166, 168 Inclined section (outer inclined section) 25, 65, 129, 169 Bending section (outer connecting section) 26, 130 Inclined section (outer connecting section) 30, 70 Outer thin-walled portion 31, 71 Outer thickness variation section (first outer thickness variation section) 32, 72 Outer thick-walled portion 33, 73 Outer thickness variation section (second outer thickness variation section) 34. Outer thin-walled portion 35, 75 Inner thin-walled portion 36, 76 Inner thickness variation section (first inner thickness variation section) 37, 77 Inner thick-walled portion 38, 78 Inner thickness variation section (second inner thickness variation section) Molds 80, 81, 90, 91

Claims

1. A sealing device for sealing a gap between an outer support member and a rotating shaft, the rotating shaft being disposed inside a hole provided in the outer support member, the sealing device comprising: An annular mounting portion is installed in the hole of the outer support member; A cylindrical portion is disposed radially inside the mounting portion; A sliding portion is disposed on the radially inner side of the cylindrical portion and slidably contacts the outer peripheral surface of the rotating shaft; as well as The corrugated portion, located between the mounting portion and the cylindrical portion, is made of an elastic body and is corrugated. The corrugated portion has: an outer inclined portion having a frustum shape; an inner inclined portion having a frustum shape and inclined in the opposite direction to the outer inclined portion; and a curved portion having a curved cross-sectional shape and connecting the outer inclined portion and the inner inclined portion. The outer inclined portion has an outer thick-walled portion, the thickness of which is greater than the thickness of the curved portion. The inner inclined portion has an inner thick wall portion, the thickness of which is greater than the thickness of the curved portion.

2. The sealing device according to claim 1, wherein, The outer inclined portion further comprises: an outer thin-walled portion connected to the curved portion and having the same thickness as the curved portion; a first outer thickness variation portion connecting the outer thin-walled portion and the outer thick-walled portion, the thickness of which increases linearly from the outer thin-walled portion toward the outer thick-walled portion; and a second outer thickness variation portion located between the outer thick-walled portion and the mounting portion, the thickness of which decreases linearly from the outer thick-walled portion, wherein the thickness of the outer thick-walled portion is uniform. The inner inclined portion further comprises: an inner thin-walled portion connected to the curved portion and having the same thickness as the curved portion; a first inner thickness variation portion connecting the inner thin-walled portion and the inner thick-walled portion and having a thickness that increases linearly from the inner thin-walled portion toward the inner thick-walled portion; and a second inner thickness variation portion located between the inner thick-walled portion and the cylindrical portion and having a thickness that decreases linearly from the inner thick-walled portion, wherein the thickness of the inner thick-walled portion is uniform.

3. The sealing device according to claim 2, wherein, The corrugated portion does not have an undercut that prevents the corrugated portion from separating from the mold forming the corrugated portion in the axial direction.

4. The sealing device according to claim 3, wherein, The outer thick-walled portion of the outer inclined portion protrudes radially outward relative to the frustum shape presented by the outer inclined portion. The outer peripheral surface of the second outer thickness variation portion of the outer inclined portion is approximately cylindrical. The inner thick-walled portion of the inner inclined portion protrudes radially inward relative to the frustum shape presented by the inner inclined portion. The inner circumferential surface of the second inner thickness variation portion of the inner inclined portion is approximately cylindrical.

5. The sealing device according to claim 3, wherein, The outer thick-walled portion of the outer inclined portion protrudes radially inward relative to the frustum shape presented by the outer inclined portion. The inner circumferential surface of the first outer thickness variation portion of the outer inclined portion is approximately cylindrical. The inner thick-walled portion of the inner inclined portion protrudes radially outward relative to the frustum shape presented by the inner inclined portion. The outer peripheral surface of the first inner thickness variation portion of the inner inclined portion is approximately cylindrical.

6. The sealing device according to any one of claims 2 to 5, wherein, The length of the outer thick-walled portion is greater than 1 / 10.6 of the length of the outer inclined portion, which includes the outer thin-walled portion, the first outer thickness variation portion, the outer thick-walled portion, and the second outer thickness variation portion and has a frustum shape. The length of the inner thick-walled portion is greater than 1 / 5.3 of the length of the inner inclined portion, which includes the inner thin-walled portion, the first inner thickness variation portion, the inner thick-walled portion, and the second inner thickness variation portion and has a frustum shape.

7. The sealing device according to any one of claims 2 to 6, wherein, The thickness of the outer thick-walled portion is more than 1.1 times the thickness of the curved portion. The thickness of the inner thick-walled portion is more than 1.1 times the thickness of the curved portion.

8. The sealing device according to any one of claims 1 to 7, wherein, The sealing device also has an inner connecting portion, which connects the cylindrical portion and the inner inclined portion of the corrugated portion. The thickness of the inner connecting portion is less than the thickness of the outer thick-walled portion and the thickness of the inner thick-walled portion.

9. The sealing device according to claim 8, wherein, The thickness of the inner thick-walled portion is more than 1.1 times the thickness of the inner connecting portion.

10. The sealing device according to any one of claims 1 to 9, wherein, The sealing device also has an outer connecting portion, which connects the mounting portion and the outer inclined portion of the corrugated portion. The thickness of the outer connecting portion is less than the thickness of the outer thick-walled portion and the thickness of the inner thick-walled portion.

11. The sealing device according to claim 10, wherein, The thickness of the outer thick-walled portion is more than 1.1 times the thickness of the outer connecting portion.

12. The sealing device according to any one of claims 1 to 11, wherein, The sealing device includes a first sealing part and a second sealing part. Each of the first sealing portion and the second sealing portion has: An annular mounting portion is installed in the hole of the outer support member; A cylindrical portion is disposed radially inside the mounting portion; A sliding portion is disposed radially inside the cylindrical portion and slidably contacts the outer peripheral surface of the rotating shaft; and The corrugated portion, located between the mounting portion and the cylindrical portion, is made of an elastic body. The corrugated portion has: an outer inclined portion having a frustum shape; an inner inclined portion having a frustum shape and inclined in the opposite direction to the outer inclined portion; and a curved portion having a curved cross-sectional shape and connecting the outer inclined portion and the inner inclined portion. The outer inclined portion has an outer thick-walled portion with a thickness greater than that of the curved portion. The inner inclined portion has an inner thick-walled portion with a thickness greater than that of the curved portion. The curved portion, the outer inclined portion, and the inner inclined portion of the first sealing portion overlap, in the axial direction, the curved portion, the outer inclined portion, and the inner inclined portion of the second sealing portion, respectively. The outer thick-walled portion of the outer inclined portion of the first sealing portion protrudes toward the opposite side of the corrugated portion of the second sealing portion relative to the frustum shape presented by the outer inclined portion. The outer inclined portion of the first sealing portion has a smooth frustum shape on the surface opposite to the corrugated portion of the second sealing portion. The inner thick-walled portion of the inner inclined portion of the first sealing portion protrudes toward the opposite side of the corrugated portion of the second sealing portion, relative to the frustum shape presented by the inner inclined portion. The inner inclined portion of the first sealing portion has a smooth frustum shape on the surface opposite to the corrugated portion of the second sealing portion. The outer thick-walled portion of the outer inclined portion of the second sealing portion protrudes toward the opposite side of the corrugated portion of the first sealing portion relative to the frustum shape of the outer inclined portion. The outer inclined portion of the second sealing portion has a smooth frustum shape on the surface opposite to the corrugated portion of the first sealing portion. The inner thick-walled portion of the inner inclined portion of the second sealing portion protrudes towards the opposite side of the corrugated portion of the first sealing portion, relative to the frustum shape presented by the inner inclined portion. The inner inclined portion of the second sealing portion has a smooth frustum shape on the surface opposite to the corrugated portion of the first sealing portion.

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