JP6722059B2 - Dust cover - Google Patents

Description

The present invention relates to a dust cover arranged in a gap between a steering shaft and a dash panel.

A steering device provided in a vehicle includes a steering shaft for transmitting rotation of a steering wheel to wheels. The steering shaft penetrates a dash panel that separates the vehicle compartment from the engine compartment. Since the steering shaft moves due to the adjustment of the position of the steering wheel, the vibration during traveling, and the like, a predetermined gap is provided between the steering shaft and the dash panel. On the other hand, it is necessary to prevent outside air containing foreign matter such as dust and noise generated in the engine room from entering the vehicle interior. Therefore, the dust cover is provided in the gap between the steering shaft and the dash panel. For example, Patent Document 1 describes an example of a dust cover.

International Publication No. 2005/068277

When two bellows are integrated as in Patent Document 1, the shape of the mold for molding the bellows tends to be complicated. On the other hand, when the two bellows are molded separately, the two bellows need to be assembled so as not to separate even in an environment susceptible to vibration.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a dust cover that can facilitate the molding of the bellows and can suppress the separation between the two bellows.

In order to achieve the above object, a dust cover according to an aspect of the present invention includes a bush attached to an outer peripheral surface of a steering shaft that penetrates a dash panel, and an annular shape disposed between the dash panel and the bush. A first bellows; an annular second bellows attached to the first bellows; and a fixing member for fixing the first bellows and the second bellows to the bush, wherein the first bellows is The second bellows is deformable according to the movement of the bush, and includes a first body portion that is deformable according to movement and a first reinforcing member that is arranged on an inner peripheral surface of the first body portion. A second main body portion and a second reinforcing member in contact with the first reinforcing member, and a concave portion provided in one of the first reinforcing member and the second reinforcing member and a convex portion provided in the other. Is fitted.

The first bellows and the second bellows can be molded separately. Therefore, the shapes of the molds for molding the first bellows and the second bellows are simple. Further, since friction occurs between the first reinforcing member and the second reinforcing member and the convex portion fits into the concave portion, the second bellows is prevented from falling off the first bellows. Therefore, the dust cover can facilitate the molding of the bellows and suppress the separation between the two bellows.

As a desirable mode of the dust cover, it is preferable that the second main body portion includes a seal lip that is in contact with an inner peripheral surface of the first bellows. As a result, the gap between the first body portion and the second body portion is closed. Therefore, the sealing performance between the first bellows and the second bellows is improved.

As a desirable mode of the dust cover, it is preferable that the first main body portion includes a seal lip that is in contact with an outer peripheral surface of the second bellows. As a result, the gap between the first body portion and the second body portion is closed. Therefore, the sealing performance between the first bellows and the second bellows is improved.

As a preferred mode of the dust cover, one of the first reinforcing member and the second reinforcing member includes a key groove that is a groove extending along the axial direction of the steering shaft, and the first reinforcing member and the second reinforcing member are provided. The other preferably includes a key that is a protrusion that fits in the key groove. Thereby, the rotation angle of the second reinforcing member with respect to the first reinforcing member is fixed. Therefore, the relative rotation of the second bellows with respect to the first bellows is suppressed.

ADVANTAGE OF THE INVENTION According to this invention, the dust cover which can shape|mold a bellows easily and can suppress the separation between two bellows can be provided.

FIG. 1 is a schematic diagram showing an outline of the steering device according to the first embodiment. FIG. 2 is a perspective view showing an outline of the steering device according to the first embodiment. FIG. 3 is a cross-sectional view showing the periphery of the dust cover according to the first embodiment. FIG. 4 is a front view of the dust cover according to the first embodiment. FIG. 5 is a sectional view taken along line AA in FIG. FIG. 6 is a front view of the first bellows according to the first embodiment. FIG. 7 is a sectional view taken along line BB in FIG. FIG. 8 is a front view of the second bellows according to the first embodiment. FIG. 9 is a sectional view taken along line CC of FIG. FIG. 10 is a schematic view showing the method of assembling the dust cover according to the first embodiment. FIG. 11 is a cross-sectional view of the dust cover according to the second embodiment. FIG. 12 is a cross-sectional view of the first bellows according to the second embodiment. FIG. 13 is a cross-sectional view of the second bellows according to the second embodiment. FIG. 14 is a sectional view of the dust cover according to the third embodiment.

Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following modes for carrying out the invention (hereinafter referred to as embodiments). Further, the constituent elements in the following embodiments include those that can be easily conceived by those skilled in the art, those that are substantially the same, and those within the so-called equivalent range. Furthermore, the constituent elements disclosed in the following embodiments can be combined appropriately.

(Embodiment 1)
FIG. 1 is a schematic diagram showing an outline of the steering device according to the first embodiment. FIG. 2 is a perspective view showing an outline of the steering device according to the first embodiment. As shown in FIG. 1, the steering device 80 includes a steering wheel 81, a first steering shaft 82, a steering force assist mechanism 83, a universal joint 84, and a second steering wheel in the order in which a force applied by an operator is transmitted. The shaft 85 and the universal joint 86 are provided and joined to the third steering shaft 87. The steering device 80 also includes an ECU (Electronic Control Unit) 90 and a torque sensor 94. The vehicle speed sensor 95 is provided on the vehicle body and outputs a vehicle speed signal V to the ECU 90 by CAN (Controller Area Network) communication.

As shown in FIG. 1, the first steering shaft 82 includes an input shaft 82a and an output shaft 82b. One end of the input shaft 82a is connected to the steering wheel 81, and the other end of the input shaft 82a is connected to the output shaft 82b. Further, one end of the output shaft 82b is connected to the input shaft 82a, and the other end of the output shaft 82b is connected to the universal joint 84. In the first embodiment, the input shaft 82a and the output shaft 82b are the carbon steel for machine structure (SC material (Carbon Steel for Machine Structural Use)) or the carbon steel pipe for machine structure (so-called STKM material (Carbon Steel Tubes for Machine Structural Purposes). )) and other general steel materials.

As shown in FIG. 1, the second steering shaft 85 is connected to the output shaft 82b via a universal joint 84. One end of the second steering shaft 85 is connected to the universal joint 84, and the other end is connected to the universal joint 86. One end of the third steering shaft 87 is connected to the universal joint 86, and the other end of the third steering shaft 87 is connected to the steering gear 88. Further, as shown in FIG. 2, the second steering shaft 85 penetrates the dash panel 10. The dash panel 10 is a partition plate that separates the vehicle compartment and the engine room.

As shown in FIG. 1, the steering gear 88 includes a pinion 88a and a rack 88b. The pinion 88a is connected to the third steering shaft 87. The rack 88b meshes with the pinion 88a. The steering gear 88 converts the rotational movement transmitted to the pinion 88a into a linear movement by the rack 88b. The rack 88b is connected to the tie rod 89. That is, the steering device 80 is a rack and pinion type.

As shown in FIG. 1, the steering force assist mechanism 83 includes a speed reducer 92 and an electric motor 93. The electric motor 93 is, for example, a brushless motor, but may be a motor including a brush (slider) and a commutator (commutator). The speed reducer 92 is, for example, a worm speed reducer. The torque generated by the electric motor 93 is transmitted to the worm wheel via the worm inside the speed reducer 92 to rotate the worm wheel. The speed reducer 92 increases the torque generated in the electric motor 93 by the worm and the worm wheel. Then, the speed reducer 92 gives an auxiliary steering torque to the output shaft 82b. That is, the steering device 80 is a column assist type.

The torque sensor 94 detects the steering force of the operator (driver) transmitted to the input shaft 82a via the steering wheel 81 as steering torque. The vehicle speed sensor 95 detects the traveling speed (vehicle speed) of the vehicle body on which the steering device 80 is mounted. The electric motor 93, the torque sensor 94, and the vehicle speed sensor 95 are electrically connected to the ECU 90.

The ECU 90 controls the operation of the electric motor 93. The ECU 90 also acquires signals from the torque sensor 94 and the vehicle speed sensor 95, respectively. That is, the ECU 90 acquires the steering torque T from the torque sensor 94 and the vehicle speed signal V of the vehicle body from the vehicle speed sensor 95. The ECU 90 is supplied with electric power from a power supply device 99 (for example, a vehicle-mounted battery) when the ignition switch 98 is on. The ECU 90 calculates the assist steering command value of the assist command based on the steering torque T and the vehicle speed signal V. Then, the ECU 90 adjusts the electric power value X supplied to the electric motor 93 based on the calculated auxiliary steering command value. The ECU 90 acquires information on the induced voltage from the electric motor 93 or information output from a resolver or the like provided on the electric motor 93 as the operation information Y.

The steering force of the operator input to the steering wheel 81 is transmitted to the speed reducer 92 of the steering force assist mechanism 83 via the input shaft 82a. At this time, the ECU 90 acquires the steering torque T input to the input shaft 82a from the torque sensor 94 and the vehicle speed signal V from the vehicle speed sensor 95. Then, the ECU 90 controls the operation of the electric motor 93. The auxiliary steering torque generated by the electric motor 93 is transmitted to the speed reducer 92.

The steering torque (including the auxiliary steering torque) output via the output shaft 82 b is transmitted to the second steering shaft 85 via the universal joint 84 and further transmitted to the third steering shaft 87 via the universal joint 86. It The steering force transmitted to the third steering shaft 87 is transmitted to the tie rod 89 via the steering gear 88 to displace the wheel.

FIG. 3 is a cross-sectional view showing the periphery of the dust cover according to the first embodiment. FIG. 4 is a front view of the dust cover according to the first embodiment. FIG. 5 is a sectional view taken along line AA in FIG. FIG. 6 is a front view of the first bellows according to the first embodiment. FIG. 7 is a sectional view taken along line BB in FIG. FIG. 8 is a front view of the second bellows according to the first embodiment. FIG. 9 is a sectional view taken along line CC of FIG. In the following description, the direction along the rotation center axis Z of the second steering shaft 85 is described as the axial direction, the direction orthogonal to the axis direction is described as the radial direction, and the tangential direction of the circle centered on the rotation center axis Z is Described as the circumferential direction. Further, in FIG. 3, the upper side is the vehicle compartment side and the lower side is the engine room side.

As shown in FIG. 3, the dash panel 10 includes a tubular member 101. The inner peripheral surface of the tubular member 101 faces the outer peripheral surface of the second steering shaft 85. The second steering shaft 85 may move due to adjustment of the position of the steering wheel 81, vibration during traveling, or the like. Therefore, an annular gap is provided between the inner peripheral surface of the tubular member 101 and the outer peripheral surface of the second steering shaft 85. The steering device 80 includes the dust cover 1 to close the gap. The dust cover 1 is fitted on the inner peripheral surface of the tubular member 101, and is positioned by a flange 102 provided at the end of the tubular member 101. The dust cover 1 is fixed to the tubular member 101 by a band 103 provided on the outer peripheral surface of the tubular member 101.

As shown in FIG. 5, the dust cover 1 includes a first bellows 3, a second bellows 4, a bush 5, a first seal lip 11, a fixing member 14, and a second seal lip 12.

The first bellows 3 is supported by the tubular member 101 of the dash panel 10, and includes a first main body portion 31 and a first reinforcing member 32 as shown in FIG. The first main body portion 31 is a member provided from the tubular member 101 to the bush 5, and is made of, for example, synthetic rubber. The first body portion 31 can be easily deformed according to the movement of the bush 5. The first body portion 31 includes a first support portion 311, a first flexible portion 312, and a first fitting portion 313. The first support portion 311 is an annular member that contacts the flange 102 of the tubular member 101. The first flexible portion 312 is a member that connects the first support portion 311 and the first fitting portion 313. As shown in FIG. 5, in a cross section including the rotation center axis Z, the first flexible portion 312 has a substantially U shape. The first fitting portion 313 is fitted on the outer peripheral surface of the bush 5.

The first reinforcing member 32 is made of metal, for example, and is integrally formed with the first main body portion 31. More specifically, the first reinforcing member 32 is steel, for example. The first reinforcing member 32 is an annular member arranged over the entire circumference of the inner peripheral surface of the first main body 31. As shown in FIG. 7, the first reinforcing member 32 is substantially L-shaped in a cross section including the rotation center axis Z. The first reinforcing member 32 is arranged inside the first support portion 311 of the first body portion 31 and on the inner peripheral surface of the first flexible portion 312. Further, as shown in FIGS. 6 and 7, the first reinforcing member 32 includes a recess 321 and a key groove 320. The recess 321 is an annular groove provided on the inner peripheral surface of the first reinforcing member 32. That is, the concave portion 321 is a groove along the circumferential direction. The key groove 320 is a groove provided on the inner peripheral surface of the first reinforcing member 32 along the axial direction. For example, the first reinforcing member 32 includes four keyways 320. The four key grooves 320 are arranged at equal intervals in the circumferential direction.

As shown in FIG. 5, the second bellows 4 is axially overlapped with the first bellows 3 and includes a second main body portion 41 and a second reinforcing member 42. The second main body 41 is a member facing the inner peripheral surface of the first main body 31, and is made of, for example, synthetic rubber. The second main body portion 41 can be easily deformed according to the movement of the bush 5. The second body portion 41 includes a second support portion 411, a second flexible portion 412, a second fitting portion 413, and a seal lip 415. The second support portion 411 is an annular member that supports the second reinforcing member 42. The second flexible portion 412 is a member that connects the second support portion 411 and the second fitting portion 413. As shown in FIG. 5, in the cross section including the rotation center axis Z, the second flexible portion 412 has a substantially U shape. The second fitting portion 413 is fitted on the outer peripheral surface of the bush 5 and is in contact with the first fitting portion 313 of the first bellows 3. The seal lip 415 is, for example, as shown in FIG. 9, a protrusion protruding in the radial direction from the second flexible portion 412. The seal lip 415 contacts the inner peripheral surface of the first bellows 3. For example, the seal lip 415 contacts the first flexible portion 312 of the first body portion 31. As a result, the gap between the first main body 31 and the second main body 41 is closed. Therefore, the sealing property between the first bellows 3 and the second bellows 4 is improved. The seal lip 415 may be in contact with the first reinforcing member 32.

The second reinforcing member 42 is made of metal, for example, and is integrally formed with the second body portion 41. More specifically, the second reinforcing member 42 is, for example, steel. The second reinforcing member 42 is an annular member arranged over the entire circumference of the outer peripheral surface of the second support portion 411. As shown in FIG. 9, the second reinforcing member 42 is substantially I-shaped in a cross section including the rotation center axis Z. Further, the second reinforcing member 42 includes a convex portion 421 and a key 420, as shown in FIGS. 8 and 9. The convex portion 421 is an annular protrusion provided on the outer peripheral surface of the second reinforcing member 42, and is fitted in the concave portion 321 of the first reinforcing member 32. Specifically, the second bellows 4 is press-fitted into the first bellows 3, so that the convex portion 421 fits into the concave portion 321. As a result, the second bellows 4 is fixed to the first bellows 3. The key 420 is a protrusion provided on the outer peripheral surface of the second reinforcing member 42 along the axial direction. For example, the second reinforcing member 42 includes four keys 420. The four keys 420 are arranged at equal intervals in the circumferential direction. The key 420 fits in the key groove 320. As a result, the rotation of the second bellows 4 with respect to the first bellows 3 is suppressed. That is, the second bellows 4 is positioned in the circumferential direction.

The second bellows 4 is fixed to the first bellows 3 by press fitting, for example. Specifically, the second reinforcing member 42 is press-fitted into the inner peripheral surface of the first reinforcing member 32. By fitting the second reinforcing member 42 on the inner peripheral surface of the first reinforcing member 32, the second bellows 4 is fixed to the first bellows 3.

The bush 5 is a bearing that rotatably supports the second steering shaft 85. The bush 5 is an annular member and is made of, for example, synthetic resin. As shown in FIG. 5, the bush 5 includes a base portion 50, a flange 51, and a plurality of grooves 59. The inner peripheral surface of the base 50 is in contact with the second steering shaft 85, and the outer peripheral surface of the base 50 is in contact with the first fitting portion 313 and the second fitting portion 413. The flange 51 projects radially outward from the end of the base 50 in the axial direction. The first fitting portion 313 is in contact with the flange 51. The flange 51 positions the first fitting portion 313 in the axial direction. The groove 59 is, for example, a groove along the axial direction, and is provided over the entire axial length of the bush 5. For example, the plurality of grooves 59 are arranged at equal intervals in the circumferential direction. The groove 59 is filled with grease as a lubricant for the second steering shaft 85. As a result, friction between the bush 5 and the second steering shaft 85 is suppressed.

The first seal lip 11 is a sealing member that separates the inside of the bush 5 from the engine room. The first seal lip 11 is, for example, synthetic rubber and is integrally formed with the bush 5. As shown in FIG. 5, the first seal lip 11 projects from the end surface of the bush 5 toward the engine room. The minimum inner diameter of the first seal lip 11 before contacting the second steering shaft 85 is smaller than the outer diameter of the second steering shaft 85. Therefore, when the first seal lip 11 contacts the second steering shaft 85, the first seal lip 11 is deformed. Due to the elasticity of the first seal lip 11, a gap between the first seal lip 11 and the second steering shaft 85 is unlikely to occur. For this reason, the first seal lip 11 can prevent foreign matter from entering the inside of the bush 5 from the engine room, and prevent leakage of grease from the inside of the bush 5 to the engine room. Further, the first seal lip 11 can suppress the sound generated in the engine room from leaking into the vehicle compartment.

The fixing member 14 is a member for fixing the first bellows 3 and the second bellows 4 to the bush 5. The fixing member 14 is an annular member made of metal, for example. As shown in FIG. 5, the fixing member 14 is substantially L-shaped in a cross section including the rotation center axis Z. The fixing member 14 is fitted on the outer peripheral surface of the second fitting portion 413 of the second bellows 4. The fixing member 14 presses the second fitting portion 413 against the bush 5 and positions the second fitting portion 413 in the axial direction. Therefore, the first fitting portion 313 and the second fitting portion 413 that are stacked in the axial direction are sandwiched by the flange 51 of the bush 5 and the fixing member 14. The flange 51 and the fixing member 14 prevent the first bellows 3 and the second bellows 4 from falling off the bush 5.

The second seal lip 12 is a sealing member that separates the inside of the bush 5 from the vehicle interior. The second seal lip 12 is, for example, synthetic rubber and is integrally molded with the fixing member 14. As shown in FIG. 5, the second seal lip 12 projects from the end surface of the fixing member 14 toward the vehicle compartment. The minimum inner diameter of the second seal lip 12 before contacting the second steering shaft 85 is smaller than the outer diameter of the second steering shaft 85. Therefore, when the second seal lip 12 contacts the second steering shaft 85, the second seal lip 12 is deformed. Due to the elasticity of the second seal lip 12, a gap between the second seal lip 12 and the second steering shaft 85 is unlikely to occur. Therefore, the second seal lip 12 can prevent grease from leaking from the inside of the bush 5 to the vehicle interior. Further, the second seal lip 12 can suppress the sound generated in the engine room from leaking into the vehicle compartment.

FIG. 10 is a schematic view showing the method of assembling the dust cover according to the first embodiment. As shown in FIG. 10, when the dust cover 1 is assembled, first, the first bellows 3 is attached to the bush 5. Specifically, the first fitting portion 313 is fitted on the outer peripheral surface of the bush 5 so as to contact the flange 51 of the bush 5.

Next, the second bellows 4 is press-fitted into the first bellows 3. Specifically, the second bellows 4 is press-fitted into the first bellows 3 with the plurality of keys 420 shown in FIG. 8 axially facing the key grooves 320 shown in FIG. 6, respectively. As a result, the convex portion 421 shown in FIG. 9 fits into the concave portion 321 shown in FIG. 7, and the second bellows 4 does not come off from the first bellows 3. Further, by fitting the key 420 into the key groove 320, the rotation of the second bellows 4 with respect to the first bellows 3 is prevented.

Next, the fixing member 14 is attached to the second bellows 4. Specifically, the fixing member 14 is pressed into the outer peripheral surface of the second fitting portion 413. The fixing member 14 is fixed to the second fitting portion 413 by the friction generated between the inner peripheral surface of the fixing member 14 and the outer peripheral surface of the second fitting portion 413.

The object to which the dust cover 1 is attached does not necessarily have to be the second steering shaft 85. For example, when the first steering shaft 82 penetrates the dash panel 10, the dust cover 1 may be applied to the first steering shaft 82. The dust cover 1 may be applied to the third steering shaft 87 when the third steering shaft 87 penetrates the dash panel 10.

The first reinforcing member 32 and the second reinforcing member 42 do not necessarily have to be made of metal. For example, the first reinforcing member 32 and the second reinforcing member 42 may be made of synthetic resin.

The first reinforcing member 32 does not necessarily have to have the concave portion 321 and the second reinforcing member 42 does not have to have the convex portion 421. For example, as shown in Embodiment 2 described later, the first reinforcing member 32 may include a member corresponding to the convex portion 421, and the second reinforcing member 42 may include a member corresponding to the concave portion 321. That is, it is sufficient that at least one of the first reinforcing member 32 and the second reinforcing member 42 has a concave portion and the other has a convex portion.

The first reinforcing member 32 does not necessarily have to have the key groove 320, and the second reinforcing member 42 does not necessarily have to have the key 420. For example, the first reinforcing member 32 may include a member corresponding to the key 420, and the second reinforcing member 42 may include a member corresponding to the key groove 320. That is, at least one of the first reinforcing member 32 and the second reinforcing member 42 may be provided with the key groove and the other may be provided with the key. Further, the number of the key grooves 320 and the number of the keys 420 do not necessarily have to be four, and at least one may be provided for each.

The seal lip 415 does not necessarily have to be provided on the second body 41. For example, as shown in Embodiment 2 described later, the first main body portion 31 may include a seal lip that contacts the outer peripheral surface of the second bellows 4.

As described above, the dust cover 1 according to the first embodiment includes the bush 5 attached to the outer peripheral surface of the steering shaft (second steering shaft 85) that penetrates the dash panel 10, the dash panel 10, and the bush 5. An annular first bellows 3 arranged therebetween, an annular second bellows 4 attached to the first bellows 3, and a fixing member 14 for fixing the first bellows 3 and the second bellows 4 to the bush 5 are provided. .. The first bellows 3 includes a first main body 31 that is deformable according to the movement of the bush 5, and a first reinforcing member 32 that is arranged on the inner peripheral surface of the first main body 31. The second bellows 4 includes a second main body portion 41 that is deformable according to the movement of the bush 5, and a second reinforcing member 42 that is in contact with the first reinforcing member 32. A convex portion 421 provided on the other side is fitted into a concave portion 321 provided on one side of the first reinforcing member 32 and the second reinforcing member 42.

The first bellows 3 and the second bellows 4 can be molded separately. Therefore, the shapes of the molds for molding the first bellows 3 and the second bellows 4 become simple. That is, the manufacture of the first bellows 3 and the second bellows 4 is easy. Further, since the convex portion 421 fits into the concave portion 321, the second bellows 4 is prevented from falling off the first bellows 3. Therefore, the dust cover 1 can facilitate the molding of the bellows and suppress the separation between the two bellows.

In addition, in the dust cover 1, the second main body portion 41 includes the seal lip 415 that is in contact with the inner peripheral surface of the first bellows 3. As a result, the gap between the first main body 31 and the second main body 41 is closed. Therefore, the sealing property between the first bellows 3 and the second bellows 4 is improved.

Further, in the dust cover 1, one of the first reinforcing member 32 and the second reinforcing member 42 includes a key groove 320 that is a groove extending along the axial direction of the steering shaft (second steering shaft 85). The other of the first reinforcing member 32 and the second reinforcing member 42 includes a key 420 that is a protrusion that fits in the key groove 320. Thereby, the rotation angle of the second reinforcing member 42 with respect to the first reinforcing member 32 is fixed. Therefore, the relative rotation of the second bellows 4 with respect to the first bellows 3 is suppressed.

(Embodiment 2)
FIG. 11 is a cross-sectional view of the dust cover according to the second embodiment. FIG. 12 is a cross-sectional view of the first bellows according to the second embodiment. FIG. 13 is a cross-sectional view of the second bellows according to the second embodiment. As shown in FIGS. 11 to 13, in the dust cover 1A according to the second embodiment, the first reinforcing member 32A of the first bellows 3A includes the convex portion 322, and the second reinforcing member 42A of the second bellows 4A. Has a recess 422. In addition, the same components as those described in the first embodiment will be denoted by the same reference numerals, and redundant description will be omitted.

The convex portion 322 is an annular protrusion provided on the inner peripheral surface of the first reinforcing member 32A. The recess 422 is an annular groove provided on the outer peripheral surface of the second reinforcing member 42A. That is, the concave portion 422 is a groove extending in the circumferential direction. The convex portion 322 is fitted in the concave portion 422. Specifically, the convex portion 322 is fitted in the concave portion 422 by press-fitting the second bellows 4A into the first bellows 3A. As a result, the second bellows 4A is fixed to the first bellows 3A.

Further, the first main body portion 31A of the first bellows 3A includes a seal lip 315. The seal lip 315 is a protrusion that protrudes from the first flexible portion 312 in the radial direction, as shown in FIG. 12, for example. The seal lip 315 contacts the outer peripheral surface of the second bellows 4A. For example, the seal lip 315 contacts the second flexible portion 412 of the second main body portion 41A. As a result, the gap between the first main body portion 31A and the second main body portion 41A is closed. Therefore, the sealing performance between the first bellows 3A and the second bellows 4A is improved. The seal lip 315 may be in contact with the second reinforcing member 42A. Note that, as in the first embodiment, the first main body portion 31A may not include the seal lip 315 and the second main body portion 41A may include the seal lip 415.

(Embodiment 3)
FIG. 14 is a sectional view of the dust cover according to the third embodiment. As shown in FIG. 14, the dust cover 1B according to the third embodiment includes a sound absorbing member 18. In addition, the same components as those described in the first embodiment will be denoted by the same reference numerals, and redundant description will be omitted.

As shown in FIG. 14, the sound absorbing member 18 is arranged between the first bellows 3 and the second bellows 4. The sound absorbing member 18 is, for example, urethane foam. After the sound absorbing member 18 is filled inside the first bellows 3, the second bellows 4 is fixed to the first bellows 3. Since the first bellows 3 and the second bellows 4 are separate bodies, it is easy to arrange the sound absorbing member 18 between the first bellows 3 and the second bellows 4. Since the dust cover 1B includes the sound absorbing member 18, it is possible to suppress the sound generated in the engine room from leaking into the vehicle compartment more than in the above-described embodiment.

1, 1A, 1B Dust cover 10 Dash panel 101 Cylindrical member 102 Flange 103 Band 11 First seal lip 12 Second seal lip 14 Fixing member 18 Sound absorbing member 3, 3A First bellows 31, 31A First body portion 311 First Support portion 312 First flexible portion 313 First fitting portion 315 Seal lip 32, 32A First reinforcing member 320 Key groove 321 Recess 322 Convex portion 4, 4A Second bellows 41, 41A Second main body portion 411 Second support portion 412 2nd flexible part 413 2nd fitting part 415 Seal lip 42, 42A 2nd reinforcement member 420 Key 421 Convex part 422 Recessed part 5 Bushing 50 Base part 51 Flange 59 Groove 80 Steering device 81 Steering wheel 82 First steering shaft 82a Input Shaft 82b Output shaft 83 Steering force assist mechanism 84 Universal joint 85 Second steering shaft 86 Universal joint 87 Third steering shaft 88 Steering gear 88a Pinion 88b Rack 89 Tie rod 90 ECU
92 Reduction gear 93 Electric motor 94 Torque sensor 95 Vehicle speed sensor 98 Ignition switch 99 Power supply device Z Rotation center axis

Claims (4)

A bush attached to the outer peripheral surface of the steering shaft that penetrates the dash panel,
An annular first bellows arranged between the dash panel and the bush;
An annular second bellows attached to the first bellows;
A fixing member for fixing the first bellows and the second bellows to the bush,
Equipped with
The first bellows includes a first main body that is deformable according to the movement of the bush, and a first reinforcing member that is arranged on an inner peripheral surface of the first main body.
The second bellows includes a second body portion that is deformable according to the movement of the bush, and a second reinforcing member that is in contact with the first reinforcing member,
A dust cover in which a convex portion provided on the other is fitted in a concave portion provided on one of the first reinforcing member and the second reinforcing member. The dust cover according to claim 1, wherein the second main body portion includes a seal lip that is in contact with an inner peripheral surface of the first bellows. The dust cover according to claim 1, wherein the first main body portion includes a seal lip that is in contact with an outer peripheral surface of the second bellows. One of the first reinforcing member and the second reinforcing member includes a key groove that is a groove along the axial direction of the steering shaft,
The dust cover according to any one of claims 1 to 3, wherein the other of the first reinforcing member and the second reinforcing member includes a key that is a protrusion that fits in the key groove.

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