Grommet

Abstract

To provide a grommet capable of inhibiting a seal from kinking even when the seal is abutted against a dash panel by causing a pressing force to act on the seal from an oblique direction.SOLUTION: A grommet G in accordance with the present invention has a padded part 4 outside a second flexible part 22. Accordingly, out of a pressing force F that acts on a seal 3 side from a cylindrical base 1 side, a panel parallel component F1 parallel to a dash panel DP is hardly propagated, but a panel vertical component F2 vertical to the dash panel DP is readily propagated. As a result, the panel vertical component F2 gets relatively large. Even when the pressing force F is caused to act on the seal from an oblique direction in order to abut the seal 3 against the dash panel DP, the seal 3 is inhibited from kinking due to turnover.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a grommet that is applied to, for example, an automobile and covers the periphery of a steering shaft that passes through a vehicle body panel (so-called dash panel) that separates a vehicle interior from an engine room. [Background technology]

[0002] The conventional grommet Gx shown in Fig. 6 is tubular and made of a specific rubber material, and is interposed between the steering shaft SH that constitutes the steering shaft of a steering device mounted on a vehicle and a shaft through hole DP1 in the dash panel DP of the vehicle body through which the steering shaft SH passes. That is, one end of the grommet Gx is attached to the top of the steering gear box GB, and the other end elastically abuts against the outer hole edge DP2 of the shaft through hole DP1, thereby preventing the intrusion of rainwater, dust, etc. through the shaft through hole DP1.

[0003] More specifically, the grommet Gx is attached so that a first seal portion 101 formed in an expanded shape on one end side of a cylindrical base portion 100 surrounding the steering shaft SH is in close contact with the outside of a gearbox cylindrical portion GB1 provided at the upper end of the steering gearbox GB. Meanwhile, the grommet Gx has a second seal portion 102 extending from the other end side of the cylindrical base portion 100 via a flexible portion 103 that flexes (bends) outward, and elastically abuts against the vehicle-exterior hole edge DP2 of the shaft through hole DP1 with an elastic force generated by bending of the flexible portion 103.

[0004] Note that, as examples of grommets having a configuration similar to that described above, those described in the following patent documents are known. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2011-79473 A Summary of the Invention [Problem to be solved by the invention]

[0006] The conventional grommet Gx is assembled by first fitting the first seal portion 101 onto the gearbox cylindrical portion GB1 of the steering gearbox GB, then passing the steering shaft SH through the shaft through hole DP1 of the dash panel DP, and thereby abutting the second seal portion 102 against the vehicle exterior hole edge DP2 of the shaft through hole DP1.

[0007] However, in order to avoid interference with other components mounted in the engine room of the vehicle, the installation direction of the grommet Gx may be restricted. In particular, there may be cases where the second seal portion 102 cannot be installed by abutting perpendicularly against the vehicle-exterior hole edge DP2 of the shaft through hole DP1, and must be installed by abutting obliquely against the vehicle-exterior hole edge DP2 of the shaft through hole DP1. In this case, the pressing force F acting on the flexible portion 103 acts obliquely against the vehicle-exterior hole edge DP2 of the shaft through hole DP1.

[0008] In this case, according to the configuration of the conventional grommet Gx, the thickness of the flexible portion 103 is relatively small compared to the cylindrical base portion 100, and the rigidity of the flexible portion 103 side relative to the cylindrical base portion 100 is relatively low, so that most of the pressing force F escapes to the outside where the flexible portion 103 extends, i.e., in the horizontal direction, and as a result, the panel parallel component F1 becomes relatively large compared to the panel vertical component F2. Therefore, the pressing force (panel vertical component F2) against the outer hole edge DP2 of the shaft through hole DP1 cannot be obtained sufficiently, and as shown in Fig. 7, due to the assembling mode from the oblique direction, the second seal portion 102 may fall over, which may cause the second seal portion 102 to turn over.

[0009] The present invention was devised with a focus on such technical problems, and aims to provide a grommet that can prevent the seal portion from curling up even when a pressing force is applied from an oblique direction to bring the seal portion into contact with the dash panel. [Means for solving the problem]

[0010] In one aspect, the present invention comprises a generally cylindrical tubular base covering an outer periphery of a steering shaft passing through a shaft through hole provided in a dash panel of a vehicle body separating a passenger compartment from an engine compartment, and a seal portion provided from an axial end of the tubular base via a flexible portion that is axially flexible and deformable so as to bulge radially outward from the tubular base, and abutting against an outer hole edge of the shaft through hole when assembled to the vehicle body, wherein the flexible portion has a first flexible portion extending radially outward from the axial end of the tubular base, and a second flexible portion extending in a curved manner toward the seal portion further than the first flexible portion and having a bent portion that is axially bendable, and a padding portion is provided on the outside of the second flexible portion to make the second flexible portion thicker than the first flexible portion.

[0011] According to this configuration, the padding provided on the outside of the second flexible portion improves the rigidity of the second flexible portion including the bent portion, which is the flexible portion on the seal portion side, and as a result, the rigidity of the first flexible portion, which is the flexible portion on the cylindrical base portion side, is relatively reduced. As a result, of the pressing force acting from the cylindrical base portion side to the seal portion side, the panel parallel component parallel to the dash panel is less likely to be transmitted to the seal portion side as the rigidity of the second flexible portion is improved by the padding. On the other hand, the panel perpendicular component perpendicular to the dash panel is more likely to be transmitted to the seal portion side as the rigidity of the first flexible portion is relatively reduced. As a result, the panel perpendicular component of the pressing force acting from the cylindrical base portion side to the seal portion side can be sufficiently secured.

[0012] Here, as a first preferred aspect of the present invention, the grommet is assembled so that the seal portion abuts against the dash panel at an angle, and it is desirable that the padding portion is provided only in a region of the circumferential region of the second flexible portion that is on the assembly direction side of the grommet relative to an assembly direction perpendicular line that passes through the center of the seal portion and is perpendicular to the assembly direction of the grommet.

[0013] In this way, when the grommet is assembled to the dash panel from an oblique direction, it is desirable that the padding portion be provided only in the circumferential region of the second flexible portion, which is on the grommet assembly direction side of the line perpendicular to the grommet assembly direction, i.e., only in the region where the seal portion is likely to tip over when the grommet is installed.

[0014] With this configuration, the rigidity of the second flexible portion is improved only in the circumferential region of the second flexible portion where the sealing portion is likely to fall over when the grommet is installed, thereby effectively preventing the sealing portion from falling over in that region.

[0015] In other words, by not providing a padding portion in the circumferential region of the second flexible portion where the sealing portion is less likely to tip over when the grommet is installed, unnecessary increase in the rigidity of the second flexible portion in that region can be suppressed, and the occurrence of problems associated with unnecessary increase in rigidity of the second flexible portion can be suppressed.

[0016] In addition, as a second preferred aspect of the present invention, it is preferable that the padding portion is formed so that, when the grommet is in a free state, the axial end portion of the padding portion on the tubular base portion side is at the same height as the root side of the first flexible portion or lower than the root side of the first flexible portion.

[0017] In this way, the end of the padding portion on the tubular base side when the grommet is in its free state is formed to be at the same position as the root side of the first flexible portion or lower than the root side of the first flexible portion, thereby eliminating the risk of the root side of the first flexible portion becoming undercut when the mold is split to mold the grommet, and improving the moldability of the grommet.

[0018] Furthermore, as a third preferred aspect of the present invention, it is desirable that the padding portion be extended to a position where the axial end portion of the padding portion on the seal portion side will not abut against the dash panel even if the vehicle is overturned so that the inner side of the seal portion is separated from the dash panel when the grommet is assembled.

[0019] In this way, by adopting a configuration in which the raised portion has an axial end portion on the seal portion side that does not abut against the dash panel even if the inner side of the seal portion is tipped over in the axial direction of the second flexible portion when the grommet is assembled, it is possible to prevent the axial end portion on the seal portion side from abutting against the dash panel when the grommet is assembled, thereby further promoting the tipping of the seal portion. Effect of the Invention

[0020] According to the present invention, by providing the padding portion on the outside of the second flexible portion, of the pressing force acting from the cylindrical base side to the seal portion side, the panel parallel component that is parallel to the dash panel is less likely to be transmitted, while the panel vertical component that is perpendicular to the dash panel is more likely to be transmitted. As a result, the panel vertical component becomes relatively large, and it is possible to suppress the occurrence of curling up due to the seal portion falling over. [Brief description of the drawings]

[0021] [Figure 1] 1 is a cross-sectional view of a main portion showing a state in which a steering device including a grommet according to the present invention is attached to a vehicle body. [Diagram 2] FIG. 2 is a bottom view of the grommet shown in FIG. [Diagram 3] 3 is an enlarged view of a main portion of the cross section taken along line AA in FIG. 2, showing a free state of the grommet. [Figure 4] 3 is an enlarged view of a main portion of a cross section taken along line AA in FIG. 2, showing an assembled state of the grommet. [Diagram 5] 3 is an enlarged view of a main portion of the cross section taken along line AA in FIG. 2, showing a state in which the seal portion is turned over when the grommet is assembled. [Figure 6] FIG. 1 is an enlarged cross-sectional view of a main portion of a conventional grommet, showing the grommet in a free state. [Figure 7] FIG. 11 is an enlarged cross-sectional view of a main portion of a conventional grommet, showing a state in which a seal portion is overturned during assembly of the grommet. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the grommet according to the present invention will be described in detail with reference to the accompanying drawings. In the following preferred embodiments, the grommet according to the present invention is applied to a steering device of an automobile, as in the conventional case.

[0023] (Grommet configuration) Fig. 1 is a cross-sectional view of a main part showing a state in which a steering device including a grommet G is attached to a vehicle body, and shows a schematic diagram of the steering device in which only a dash panel DP is shown in cross section. In the following description, the top side of Fig. 1, which corresponds to the upper side in the vertical direction, is defined as "upper" and the bottom side of Fig. 1, which corresponds to the lower side in the vertical direction, is defined as "lower" based on the top and bottom of the vehicle body.

[0024] As shown in Fig. 1, the steering device is equipped with a steering shaft SH having first to third steering shafts SH1 to SH3 connected by first and second universal joints J1 and J2, which are well-known universal joints. The first steering shaft SH1, which is arranged at one axial end of the steering shaft SH, faces the interior of the vehicle and is connected to a steering wheel SW. The third steering shaft SH3, which is arranged at the other axial end of the steering shaft SH, penetrates a dash panel DP, which is a vehicle body panel, faces the engine room, and has a tip end connected to wheels (not shown) via a predetermined steering mechanism (such as a rack and pinion mechanism) housed inside a steering gear box GB.

[0025] A grommet G for keeping the inside and outside of the vehicle compartment watertight is interposed between the shaft through hole DP1 penetrating the dash panel DP and the third steering shaft SH3. The grommet G is cylindrical and made of a predetermined rubber material, and has a cylindrical base 1 covering the outer periphery of the third steering shaft SH3 penetrating the dash panel DP, a flexible part 2 extending in a curved shape radially outward from one axial end (upper end) of the cylindrical base 1 and capable of being flexibly deformed in the axial direction of the third steering shaft SH3, and a seal part 3 provided at the tip end (upper end) of the flexible part 2 and capable of abutting against the outer hole edge DP2 of the shaft through hole DP1 when assembled to the vehicle body (dash panel DP), which are integrally formed by die molding.

[0026] The cylindrical base 1 has a general portion 11 that covers the outer periphery of the third steering shaft SH3, a mounting base 12 that expands in a stepped shape toward one axial end side (lower end side) of the general portion 11 and is attached to a roughly cylindrical gearbox cylindrical portion GB1 provided at the upper end of the steering gearbox GB, and a connection base 13 that expands in diameter toward the other axial end side (upper end side) of the general portion 11 and connects the general portion 11 to the flexible portion 2.

[0027] The general portion 11 is formed in a generally cylindrical shape and extends along the axial direction of the third steering shaft SH3 so as to be oblique to the dash panel DP. In other words, the cylindrical base portion 1 extends along the central axis CS of the third steering shaft SH3 that intersects with the central axis CH of the shaft through hole DP1.

[0028] The mounting base 12 is provided with a stepped diameter expansion from the general portion 11, and has a lip (not shown) on the inner periphery side that is provided so as to be able to come into close contact with the outer periphery of the gearbox cylindrical portion GB1. That is, the mounting base 12 makes the gap between the mounting base 12 and the gearbox cylindrical portion GB1 liquid-tight by the lip (not shown) coming into close contact with the outer periphery of the gearbox cylindrical portion GB1.

[0029] The connection base 13 is bent relative to the general portion 11 and extends along the central axis CH of the shaft through hole DP1. The connection base 13 is expanded relative to the general portion 11 and has an outer diameter larger than that of the general portion 11 and smaller than that of the flexible portion 2. Specifically, the connection base 13 has a first connection base 131 having a conical tapered shape extending obliquely radially outward from the other axial end (upper end) of the general portion 11, and a second connection base 132 extending from the upper end of the first connection base 131 approximately along the central axis CH. Between the first connection base 131 and the second connection base 132, a bent portion 133 is provided that is thinner than the first and second connection bases 131 and 132 (see FIG. 3).

[0030] The flexible portion 2 is provided on the upper end of the second connection base 132 so as to be continuous and endless over the entire circumferential area of ​​the second connection base 132, and is formed to be flexible and deformable in the axial direction of the third steering shaft SH3. The upper end of the flexible portion 2 is provided with a seal portion 3 that can elastically contact the outer hole edge DP2 of the shaft through hole DP1 based on an elastic force generated by the flexible portion 2 being flexible and deformed.

[0031] With the above-described configuration, grommet G is positioned in a clamped state between the gearbox cylindrical portion GB1 of the steering gearbox GB and the vehicle exterior hole edge DP2 of the shaft through hole DP1 of the dash panel DP, and based on the elastic force of the flexibly deformed flexible portion 2, the mounting base 12 of the tubular base 1 elastically abuts against the end face of the gearbox cylindrical portion GB1 of the steering gearbox GB, and the sealing portion 3 elastically abuts against the vehicle exterior hole edge DP2 of the shaft through hole DP1 of the dash panel DP, so that grommet G is assembled and held in place on the vehicle body while demonstrating its sealing function.

[0032] 1 indicates the direction in which grommet G is attached to the vehicle body (dash panel DP). In other words, in order to avoid interference with other parts mounted in an engine room (not shown), grommet G is attached so that seal portion 3 abuts obliquely against dash panel DP as indicated by arrow Z in FIG 1, rather than in a direction in which seal portion 3 abuts perpendicularly against dash panel DP.

[0033] FIG. 2 shows a bottom view of the grommet G shown in FIG. 1, seen from the seal portion 3 side.

[0034] As shown in Fig. 2, in a plan view, grommet G has a general portion 11 and a mounting base portion 12 of a cylindrical base portion 1 formed in a roughly circular shape, and a connection base portion 13, a flexible portion 2, and a sealing portion 3 formed in an oval (elliptical) shape extending in the left-right direction of Fig. 2. Note that arrow D shown in Fig. 2 indicates the horizontal movement direction of grommet G when assembling it to the vehicle body (dash panel DP shown in Fig. 1) (hereinafter, abbreviated as "grommet assembling direction").

[0035] Furthermore, grommet G has a padding portion 4 that forms second flexible portion 22 thicker than a first flexible portion 21, which will be described later, in a circumferential region indicated by R in Fig. 2 outside second flexible portion 22 of flexible portion 2, which will be described later. It is desirable that this padding portion 4 extend within a range of approximately 45 degrees (circumferential region R) on both sides in the circumferential direction with respect to grommet assembly direction D.

[0036] The padding 4 only needs to be provided on the grommet assembly direction D side, that is, only in a region of the circumferential region R of the second flexible portion 22 on the grommet assembly direction D side of a line V orthogonal to the grommet assembly direction that passes through the center P of the flexible portion 2 and is perpendicular to the grommet assembly direction D. In other words, the formation range of the padding 4 can be set arbitrarily, and is not necessarily limited to the range of the circumferential region R shown in FIG.

[0037] Fig. 3 shows the free state of grommet G, and is an enlarged view of the main part of the longitudinal cross section of grommet G taken along line AA in Fig. 2. Fig. 4 shows the state in which flexible portion 2 is bent and deformed when grommet G is attached to the vehicle body (dash panel DP), and is an enlarged view of the main part of the longitudinal cross section of grommet G taken along line AA in Fig. 2.

[0038] 3, the flexible portion 2 has a first flexible portion 21 extending from the other axial end (upper end) of the cylindrical base 1 (second connection base 132) radially outward of the cylindrical base 1, and a second flexible portion 22 extending in a curved shape toward the seal portion 3 side from the first flexible portion 21. That is, the flexible portion 2 has the first flexible portion 21 and the second flexible portion 22 formed with a generally constant thickness that is thinner than the cylindrical base 1, and is provided to bulge radially outward from the other axial end (upper end) of the cylindrical base 1, and is formed to be flexible and deformable in the axial direction of the third steering shaft SH3.

[0039] 3, the first flexible portion 21 is formed so that in the free state of the grommet G, the distance from the seal lip 32 is generally constant and horizontal, or the distance from the seal portion 3 (panel facing surface 311) gradually decreases toward the second flexible portion 22. In other words, the first flexible portion 21 is formed so that the root portion 210 side connected to the connection base 13 (second connection base 132) is the lowest, and is formed so that the first flexible portion 21 is horizontal and gradually increases toward the second flexible portion 22, or is inclined and gradually increases toward the second flexible portion 22.

[0040] The second flexible portion 22 has an arc-shaped cross section that bulges radially outward from the tip of the first flexible portion 21 toward the seal portion 3 (root portion 310 of the support portion 31), and has a bent portion 23 that is bendable in the axial direction in the middle of the axial direction of the third steering shaft SH3 (see FIG. 1). In other words, the second flexible portion 22 is provided so as to be able to flexibly deform in the axial direction with the bent portion 23 as a bending point, and flexibly deforms in the axial direction based on a pressing force F acting on the root portion 210 of the first flexible portion 21 from the cylindrical base portion 1 side, thereby pressing the tip side of the support portion 31 against the dash panel DP as indicated by arrow M in FIG. 4.

[0041] The seal portion 3 has a support portion 31 extending radially inward at the tip portion of the second flexible portion 22, and a seal lip 32 protruding from the outer circumferential edge portion of the support portion 31 and abutting against the vehicle exterior hole edge DP2 of the shaft through hole DP1. That is, the seal portion 3 watertightly seals the vehicle exterior hole edge DP2 of the shaft through hole DP1 by the seal lip 32 elastically contacting the vehicle exterior hole edge DP2 of the shaft through hole DP1 based on an elastic force generated by the flexible portion 2 being flexibly deformed.

[0042] The support portion 31 is formed so that its cross section is generally trapezoidal, with the thickness T being greatest on the outer periphery side and gradually decreasing from the outer periphery side toward the inner periphery side. Specifically, as shown in Fig. 3, the support portion 31 is formed so that in the free state of the grommet G, the panel facing surface 311 is generally parallel to the first flexible portion 21, and in the state in which the grommet G is assembled to the vehicle (not shown), the panel facing surface 311 is generally parallel to the dash panel DP. Meanwhile, as shown in Fig. 3, the panel opposite surface 312 of the support portion 31 is formed in a tapered shape that is inclined upward from the outer periphery side toward the inner periphery side in the free state of the grommet G.

[0043] The seal lip 32 protrudes from the outer peripheral edge of the panel-facing surface 311 of the support part 31, and is provided continuously and endlessly over the entire circumferential area of ​​the panel-facing surface 311 of the support part 31. That is, the seal lip 32 comes into close contact with the entire circumference of the vehicle-exterior hole edge DP2 of the shaft through hole DP1 in the dash panel DP, thereby sealing the vehicle-exterior hole edge DP2 watertightly, and preventing the intrusion of moisture, dust, and the like from the outside of the vehicle into the passenger compartment through the vehicle-exterior hole edge DP2.

[0044] 3 and 4, in a predetermined circumferential region R (see FIG. 2) in the second flexible portion 22, a padding portion 4 that makes the second flexible portion 22 thicker than the first flexible portion 21 is provided on the outer side of the second flexible portion 22. The padding portion 4 is provided integrally with the second flexible portion 22 with a generally constant thickness so as to follow the outer side of the second flexible portion 22, and extends from the connection portion of the second flexible portion 22 with the first flexible portion 21 to the middle position of the support portion 31.

[0045] More specifically, as shown in Fig. 3, the lower end portion of the padding portion 4, which is the axial end portion on the cylindrical base 1 side, extends to a position that is the same as or lower than the root portion 210 side of the first flexible portion 21 in the free state of the grommet G, i.e., to the connection portion of the second flexible portion 22 with the first flexible portion 21. Here, the lower end portion, which is one axial end portion of the padding portion 4, is formed in a smooth, continuous flat shape along the outer surface of the first flexible portion 21 (see Fig. 3).

[0046] 3 and 4, the upper end of the padding portion 4, which is the axial end on the seal portion 3 side, extends to an outer middle position of the support portion 31 of the seal portion 3. To be precise, the upper end of the padding portion 4 extends to a position where it will not come into contact with the dash panel DP even if the support portion 31 is overturned (see FIG. 5) so that the inner periphery side of the support portion 31 is separated from the dash panel DP during installation of the grommet G.

[0047] (Effects of the present invention) Below, the procedure for assembling the grommet G will be explained, and the characteristic functions and effects of the grommet G will also be explained.

[0048] To install the grommet G, first, one end of the grommet G (the mounting base portion 12 of the cylindrical base portion 1) through which the third steering shaft SH3 passes is fitted into the gear box cylindrical portion GB1 of the steering gear box GB. Then, while the third steering shaft SH3 facing the outside from the seal portion 3 side is inserted into the shaft through hole DP1, the other end of the grommet G (the seal lip 32 of the seal portion 3) is elastically contacted with the outer hole edge DP2 of the shaft through hole DP1. As a result, the grommet G is held in a sandwiched state between the steering gear box GB and the dash panel DP, and the grommet G is installed to the vehicle body together with the steering device.

[0049] At this time, the installation direction of the grommet G (for example, arrow Z in FIG. 1) may be restricted in order to avoid interference with other components mounted in the engine room of the vehicle. In other words, the seal portion 3 cannot be installed so as to abut against the dash panel DP perpendicularly, and may have to be installed so as to abut against the dash panel DP at an angle. In such an installation mode, the pressing force F acting on the flexible portion 2 acts obliquely on the dash panel DP.

[0050] Here, in the configuration of the conventional grommet Gx, as shown in Fig. 6, the thickness of the flexible portion 103 is relatively small compared to the cylindrical base portion 100, and the rigidity of the flexible portion 103 side relative to the cylindrical base portion 100 is relatively low. For this reason, most of the pressing force F escapes to the outside where the flexible portion 103 extends, that is, in the horizontal direction, and as a result, the panel parallel component F1 becomes relatively large compared to the panel vertical component F2. As a result, the pressing force (panel vertical component F2) against the dash panel DP cannot be obtained sufficiently, and due to the assembling mode from the oblique direction, as shown in Fig. 7, there is a risk that the second seal portion 102 will fall over and be turned up.

[0051] In contrast, in the grommet G according to the present embodiment, the padding 4 provided on the outside of the second flexible portion 22 improves the rigidity of the second flexible portion 22 including the bent portion 23, which is the flexible portion on the sealing portion 3 side, and as a result, the rigidity of the first flexible portion 21, which is the flexible portion on the cylindrical base 1 side, is relatively reduced. As a result, of the pressing force F acting from the cylindrical base 1 side to the sealing portion 3 side, the panel parallel component F1 parallel to the dash panel DP is less likely to be transmitted to the sealing portion 3 side due to the improvement in the rigidity of the second flexible portion 22 by the padding 4 described above. On the other hand, the panel vertical component F2 perpendicular to the dash panel DP is more likely to be transmitted to the sealing portion 3 side due to the relative decrease in the rigidity of the first flexible portion 21 described above. As a result, the panel vertical component F2 of the pressing force F acting from the cylindrical base 1 side to the sealing portion 3 side can be sufficiently secured.

[0052] In this way, in the grommet G according to this embodiment, by providing the padding portion 4 on the outside of the second flexible portion 22, of the pressing force F acting from the cylindrical base portion 1 side to the seal portion 3 side, the panel parallel component F1 parallel to the dash panel DP is less likely to be transmitted, while the panel vertical component F2 perpendicular to the dash panel DP is more likely to be transmitted. This makes the panel vertical component F2 relatively large, suppressing the occurrence of curling due to the seal portion 3 tipping over, and ensuring good watertightness by the seal portion 3.

[0053] Furthermore, in the grommet G of this embodiment, the padding portion 4 is provided only in the circumferential region R of the second flexible portion 22, in a region on the grommet assembly direction D side of a grommet assembly direction perpendicular line V that passes through the center P of the flexible portion 2 (sealed portion 3) and is perpendicular to the grommet assembly direction D.

[0054] As described above, in this embodiment, the padding portion 4 is provided only in a region of the circumferential region R of the second flexible portion 22 that is on the grommet assembly direction D side of the line V perpendicular to the grommet assembly direction, i.e., in a region where the seal portion 3 is likely to tip over when the grommet G is attached. Therefore, the rigidity of the second flexible portion 22 is improved only in the circumferential region R of the second flexible portion 22 where the seal portion 3 is likely to tip over when the grommet G is attached, and tipping over of the seal portion 3 in that region R can be effectively suppressed.

[0055] In other words, by not providing the padding portion 4 in the circumferential region of the second flexible portion 22 where the sealing portion 3 is less likely to tip over when the grommet G is installed, unnecessary increase in the rigidity of the second flexible portion 22 in that region is suppressed, and the occurrence of problems associated with unnecessary increase in the rigidity of the second flexible portion 22 can be suppressed.

[0056] Furthermore, in this embodiment, the padding portion 4 is formed such that, in the free state of the grommet G, the axial end portion of the padding portion 4 on the cylindrical base 1 side is at the same height as the root portion 210 side of the first flexible portion 21 or is lower than the root portion 210 side of the first flexible portion 21. Therefore, there is no risk of the root portion 210 side of the first flexible portion 21 becoming an undercut when the mold is split to mold the grommet G, and the moldability of the grommet G can be improved.

[0057] Furthermore, if the padding portion 4 extends to the axial end of the seal portion 3, when the inner side of the seal portion 3 falls over and away from the dash panel DP during assembly of the grommet G, the axial end of the padding portion 4 on the seal portion 3 side may abut against the dash panel DP, which may further exacerbate the falling over of the seal portion 3.

[0058] Therefore, in the grommet G according to this embodiment, the padding portion 4 is extended to a position where the axial end portion of the padding portion 4 on the seal portion 3 side will not abut against the dash panel DP even if the grommet G is tipped over so that the inner circumferential side of the seal portion 3 is separated from the dash panel DP when the grommet G is assembled. This makes it possible to suppress a problem in which the axial end portion of the padding portion 4 on the seal portion 3 side abuts against the dash panel DP, which would further promote the tipping over of the seal portion 3, even if the seal portion 3 is tipped over when the grommet G is assembled.

[0059] The present invention is not limited to the configuration disclosed in the above embodiment, and the detailed configuration of the grommet G, such as the shape of the tubular base 1 and the seal portion 3, which are not directly related to the configuration of the present invention, as well as the shape and size of parts that are directly related to the configuration of the present invention, such as the padding portion 4, can be freely modified within the scope of the spirit of the present invention in accordance with the specifications of the steering device or vehicle body to which it is applied. [Explanation of symbols]

[0060] G…Grommet 1...Cylindrical base 2...Flexible part 21...First flexible part 22...Second flexible part 23…Bend 3…Sealing section 4…Meat section DP…Dash panel SH…Steering shaft

Claims

1. a generally cylindrical base portion covering an outer periphery of a steering shaft passing through a shaft through hole provided in a dash panel of a vehicle body separating a passenger compartment from an engine room; a seal portion provided via a flexible portion that is axially flexible and deformable so as to bulge from an axial end portion of the cylindrical base portion toward a radially outward direction of the cylindrical base portion, the seal portion being in contact with an outer-vehicle side hole edge of the shaft through hole when the cylindrical base portion is assembled to the vehicle body; Equipped with the flexible portion includes a first flexible portion extending from an axial end portion of the cylindrical base portion toward the radial outside of the cylindrical base portion, and a second flexible portion extending in the axial direction of the cylindrical base portion while curving from the first flexible portion toward the seal portion and having a bent portion that can be bent in the axial direction, the seal portion includes a support portion that is provided at a tip end portion of the second flexible portion and extends radially inwardly of the cylindrical base portion, and a seal lip that protrudes from an outer circumferential edge portion of the support portion and abuts against an outer circumferential edge of the shaft through hole on a vehicle exterior side, A grommet, comprising: a padding portion provided on the outer side of the second flexible portion connecting the first flexible portion and the support portion, the padding portion making the second flexible portion thicker than the first flexible portion.

2. The grommet is assembled to the dash panel such that the seal portion is in oblique contact with the dash panel, The grommet according to claim 1, characterized in that the padding portion is provided only in a region of the circumferential region of the second flexible portion that is on the side of the assembly direction of the grommet relative to a line perpendicular to the assembly direction that passes through the center of the seal portion and is perpendicular to the assembly direction of the grommet.

3. A grommet as described in claim 1 or 2, characterized in that, when the grommet is in a free state, the padding portion is formed so that the axial end portion of the padding portion on the tubular base portion side is at the same height as the root side of the first flexible portion or lower than the root side of the first flexible portion.

4. A grommet as described in any one of claims 1 to 3, characterized in that the padding portion is extended to a position where the axial end portion of the padding portion on the sealing portion side will not abut against the dash panel even if the vehicle falls over so that the tip side of the support portion farther from the second flexible portion is separated from the dash panel when the grommet is assembled.

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