JP6220175B2 - Sealing device - Google Patents

Description

  The present invention relates to a sealing device used as a dust seal means in, for example, an automobile steering column hole.

  FIG. 3 shows an example of a steering apparatus for an automobile. Reference numeral 101 denotes a steering wheel, 102 denotes a steering wheel that is rotated by the steering wheel 101, and reciprocates a tie rod (not shown) via a rack and pinion gear. It is a shaft. A conventional sealing device (steering dust seal) as shown in FIG. 4 is attached as a dust seal means to a portion (X portion in FIG. 3) where the steering shaft 102 penetrates the column hole of the front dash panel 103. .

  That is, the conventional sealing device shown in FIG. 4 includes a metal fixing ring 201 that is fixed to the column hole of the front dash panel 103 of FIG. 3 and a seal lip 202 that is in close contact with the outer peripheral surface of the steering shaft 102 of FIG. The bumper portion 203 formed at the base, the outer peripheral base portion 204a are integrally joined to the stationary ring 201, and the inner diameter portion of the bellows portion 204 is continuous with the bumper portion 203, and the inner periphery of the bumper portion 203 And a sliding ring 205 made of a low friction synthetic resin material. The seal lip 202, the bumper portion 203, and the bellow portion 204 are formed integrally with the stationary ring 201 with a rubber-like elastic material (rubber material or synthetic resin material having rubber-like elasticity), and the sliding ring 205 has low friction and resistance. Molded with a synthetic resin material with excellent wear.

  And this kind of sealing device seals between the column hole of the front dash panel 103 and the steering shaft 102, so that inflow of rainwater and dust from the engine room S1 side to the vehicle compartment S2 and the heat in the engine room S1. In addition to preventing the inflow of outside air accompanying the engine, the engine sound and running sound are blocked (see, for example, the following prior art documents).

  Further, the sliding ring 205 held on the inner periphery of the bumper portion 203 is a stick-slip when the steering shaft 102 is greatly decentered with respect to the column hole and slides in a pressure contact state with the outer peripheral surface of the steering shaft 102. In addition to preventing the generation of abnormal noise called “squeal” due to the phenomenon, the increase in friction torque is suppressed.

JP 2010-091077 A JP 2008-032208 A

  However, in this type of sealing device, in order to maintain the sealing performance by the seal lip 202 even when the steering shaft 102 is greatly decentered with respect to the column hole, the followability with respect to the decentering is ensured by the deformation of the bellows portion 204, It is necessary to make the clearance between the moving ring 205 and the steering shaft 102 as small as possible. For this reason, it is difficult to hold a sufficient amount of grease between the sliding ring 205 and the steering shaft 102, and the amount of grease supplied to the seal lip 202 may be reduced.

  Further, in recent years, the steering shaft 102 has been increasingly required to have a highly eccentric operation, and in addition, it is difficult to expand the mounting space of the sealing device. There is a problem that is becoming difficult to rely only on.

  The present invention has been made in view of the above points, and its technical problem is to provide a sealing device that ensures excellent followability to the eccentricity of the shaft. The problem is to provide a sealing device that ensures a sufficient supply amount of grease to the seal lip in addition to ensuring followability.

Sealing device according to the invention 請 Motomeko 1 includes a first member, a sealing device for sealing between the shaft passing through the first member, a fixed portion fixed to the first member, the A seal lip in intimate contact with the outer peripheral surface of the shaft; a bellows portion that extends freely between the base of the seal lip and the fixed portion; and a slide that is held on the inner periphery of the base of the seal lip and a ring, this sliding ring is obtained by forming a cylindrical recess to provide a spring property in the radial direction on the sliding ring by having a continuous shape in the circumferential direction extends axially .

  In the above configuration, the sliding ring made of a synthetic resin material with low friction held at the inner periphery of the base of the seal lip is in pressure contact with the outer peripheral surface of the shaft when the shaft is greatly decentered with respect to the first member. Even in the case of sliding with, by sliding with low friction, the generation of noise due to the stick-slip phenomenon is prevented and the increase of the friction torque is suppressed. And since this sliding ring has a cylindrical recess, it is given springiness in the radial direction, so that the sliding ring itself has a function of absorbing eccentricity in addition to the eccentricity following by deformation of the bellows part It becomes.

Sealing device according to the invention of claim 2, in the configuration described in claim 1, in which the cylindrical recess of the sliding ring is opened to the sealing lip side.

  In the above configuration, if the cylindrical recess of the sliding ring is filled with grease, when the sliding ring is pressed against the outer peripheral surface of the shaft and deformed in the radial direction by the eccentric operation of the shaft, the cylindrical recess is Since a part of the grease is pushed out to the seal lip side, the grease is supplied to the seal lip.

  According to the sealing device according to the present invention, in addition to the eccentric followability due to the deformation of the bellows portion, the sliding ring itself has a function of absorbing the eccentricity by forming the cylindrical concave portion, so that high eccentric followability can be ensured. Even if it is greatly decentered, the excellent sealing performance by the seal lip is maintained.

  In addition, since the cylindrical concave portion of the sliding ring can be provided with a function of retaining grease and a function of supplying this grease to the seal lip, good lubricity of the seal lip can be ensured.

1 is a half sectional view showing a first embodiment of a sealing device according to the present invention by cutting along a plane passing through an axis. FIG. 6 is a half sectional view showing a second embodiment of the sealing device according to the present invention by cutting along a plane passing through an axis. It is explanatory drawing which shows an example of the steering device of a motor vehicle roughly. It is a half sectional view which cuts and shows the conventional sealing device by the plane which passes along an axis.

  Hereinafter, preferred embodiments of a sealing device according to the present invention will be described with reference to the drawings. First, FIG. 1 shows a first embodiment.

  The sealing device according to this embodiment includes a fixed ring 1 that is press-fitted into a column hole of a front dash panel (not shown) in an automobile, and a seal lip 2 that is in close contact with an outer peripheral surface of a steering shaft 10 that passes through the column hole. The bumper 3 having a larger diameter and thicker than the seal lip 2 and the outer peripheral portion 4a are integrally vulcanized and bonded to the inner peripheral surface of the stationary ring 1 and the inner peripheral portion 4b. Includes a bellows portion 4 continuous to the bumper portion 3, a reinforcing ring 5 embedded in the bumper portion 3, and a sliding ring 6 integrally held on the inner periphery of the bumper portion 3. The front dash panel corresponds to the first member recited in claim 1, and the steering shaft 10 corresponds to the shaft recited in claim 1.

  The fixed ring 1 is formed of a metal in a cylindrical shape and is press-fitted and fixed to the inner peripheral surface of the column hole of the front dash panel, and corresponds to the fixed portion described in claim 1.

  The seal lip 2, the bumper portion 3, and the bellows portion 4 are integrally formed with the stationary ring 1 with a rubber-like elastic material (rubber material or synthetic resin material having rubber-like elasticity). Among these, the seal lip 2 faces the engine room S1 side in the mounted state, and is in close contact with the outer peripheral surface of the steering shaft 10 so as to be slidable with an appropriate fastening margin.

  Further, when the steering shaft 10 is greatly decentered with respect to the column hole of the front dash panel, the bumper portion 3 receives the eccentric force from the steering shaft 10 via the sliding ring 6, and this is received by the bellows portion 4. By transmitting, it prevents a large radial load from acting on the seal lip 2, and has a substantially conical cylindrical shape with a gradually increasing diameter toward the opposite side of the seal lip 2. Are formed with concave and convex strips that are continuous in the circumferential direction for fitting with the outer peripheral surface of the sliding ring 6.

  Further, the bellows part 4 is for securing the followability of the seal lip 2, the bumper part 3 and the sliding ring 6 by freely deforming with respect to the eccentricity of the steering shaft 10, and is formed in an annular sheet shape. A shape (cross-sectional shape shown in the figure) cut along a plane passing through the axis is a shape meandering in a wave shape in the axial direction.

  The reinforcing ring 5 is made of metal in an annular shape, and is provided integrally with the bumper portion 3 in order to maintain the roundness of the bumper portion 3.

  The sliding ring 6 is formed of a synthetic resin material having low friction and excellent wear resistance, and has an outer peripheral surface that is continuously formed in the circumferential direction on the inner peripheral surface of the bumper portion 3. It is held in a state where it is prevented from coming off by fitting with the strips. The inner peripheral surface of the sliding ring 6 is slightly larger than the outer diameter of the steering shaft 10, and a large number of lubricating grooves 61 extending in the axial direction are formed at equal intervals in the circumferential direction. A cylindrical recess 62 that extends in the axial direction and continues in the circumferential direction is formed in the middle portion in the thickness direction of 6 and opens at the end opposite to the seal lip 2 (vehicle compartment S2 side). That is, the sliding ring 6 is formed in a substantially V-shaped or substantially U-shaped cross-sectional shape by the cylindrical recess 62.

  The sealing device having the above configuration seals between the column hole opened in the front dash panel and the steering shaft 10 inserted therethrough by the seal lip 2 and the bellows portion 4, thereby enabling the engine room S <b> 1 side. Rain water and dust, or hot air and outside air in the engine room S1 are prevented from flowing into the vehicle compartment S2, and engine noise and running noise are blocked.

  When the steering shaft 10 is greatly decentered with respect to the column hole of the front dash panel, the bellows portion 4 is greatly bent and stretched in the radial direction, and the steering shaft 10 is part of the circumferential direction. The sliding ring 6 is made of a synthetic resin material having a low friction, so that the stick-slip phenomenon does not occur with the sliding with the outer peripheral surface of the steering shaft 10. Therefore, the generation of abnormal noise called “squeal” is effectively prevented.

  Further, since the lubricating groove 61 formed on the inner peripheral surface of the sliding ring 6 can be applied with a lubricant such as grease and held, good lubricity can be maintained and stick-slip can be maintained. Generation of abnormal noise due to the phenomenon is effectively prevented.

  Further, since the steering shaft 10 is greatly decentered with respect to the column hole of the front dash panel, even if the steering shaft 10 is pressed against the inner peripheral surface of the sliding ring 6 in a part of the circumferential direction, the sliding ring 6 has a substantially V-shaped or U-shaped cross-sectional shape due to the cylindrical recess 62, so that the spring property in the radial direction is given, so that in addition to the eccentric followability by the bellows portion 4, the sliding ring 6 It itself has a function of absorbing eccentricity. For this reason, high eccentricity followability can be ensured, and excellent sealing performance and lubricity are maintained even when the steering shaft 10 is greatly eccentric.

  Next, FIG. 2 shows a second preferred embodiment of the sealing device according to the present invention.

  In this embodiment, the difference from the first embodiment described above is that the cylindrical recess 62 of the sliding ring 6 opens at the end on the seal lip 2 side. Other parts can be configured in the same manner as in the first embodiment.

  According to the second embodiment, if the cylindrical recess 62 of the sliding ring 6 is filled with grease, the sliding ring 6 is brought into pressure contact with the outer peripheral surface of the steering shaft 10 by the eccentric operation of the steering shaft 10. When being deformed in the radial direction, part of the grease in the cylindrical recess 62 is pushed out to the seal lip 2 side, so that the grease supply function to the seal lip 2 is provided.

  Therefore, in addition to the effect of the first embodiment, even if the clearance between the sliding ring 6 and the steering shaft 10 is made as small as possible, even if the amount of grease retained in this clearance is small, the cylindrical recess Maintenance of a stable lubrication state of the seal lip 2 by supplying grease from 62 can be expected.

  In the first and second embodiments described above, the description has been given of the case having only one set of the seal lip 2, the bumper portion 3, the bellows portion 4, and the sliding ring 6. As in 1 or Patent Document 2, a configuration in which a plurality of sets of the seal lip 2, the bumper portion 3, the bellows portion 4, and the sliding ring 6 are arranged in the axial direction can also be applied.

1 Fixed ring (fixed part)
2 Seal lip 3 Bumper (base of seal lip)
4 Bellows 5 Reinforcement ring 6 Sliding ring 61 Lubrication groove 62 Cylindrical recess 10 Steering shaft (shaft)

Claims (2)

A sealing device for sealing between a first member and a shaft penetrating the first member,
A fixing portion fixed to the first member;
A seal lip in close contact with the outer peripheral surface of the shaft;
A bellows part that extends between the base of the seal lip and the fixed part and is freely deformable;
A sliding ring held on the inner periphery of the base of the seal lip ;
With
A sealing device , wherein the sliding ring has a cylindrical recess that extends in the axial direction and is continuous in the circumferential direction to give the sliding ring springiness in the radial direction . Sealing device according to claim 1, characterized in that the cylindrical recess of the sliding ring is opened to the sealing lip side.

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