JP2006226489A - Sealing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing device adaptable for highly eccentric operation as required recently without the need for forming a through-hole in a component. <P>SOLUTION: The sealing device 1 comprises a mounted part 5 mounted on the inner periphery of a housing 2 through which a shaft 4 is inserted, a bellows part 7 provided on the inner periphery side of the mounted part 5, and a sealing part 6 provided on the further inner periphery side of the bellows part 7 and slidably put in close contact with the peripheral face of the shaft 4. A steel plate sliding part 8 is integrally held on the outer periphery side of the bellows part 7 in the radially outward direction. The steel plate sliding part 8 is held slidably in the radial direction by a pair of axially sliding supporting parts 9, 10 provided on the inner periphery side of the mounted part 5. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sealing device according to a sealing technique, and more particularly to a sealing device suitable for use in a shaft seal portion having a large shaft eccentricity or mounting eccentricity, such as a dust seal of a steering shaft in a vehicle such as an automobile. . The sealing device of the present invention is used for general-purpose machines and the like in addition to the above vehicles.

  Conventionally, a sealing device 51 shown in FIG. 6 is known, and this sealing device 51 is configured as follows. The sealing device 51 is a vehicle steering dust seal (see FIG. 5 published in Patent Document 1).

  That is, the sealing device 51 seals a gap between the peripheral surface of the shaft hole 53 provided in the front dash panel 52 which is a housing and the peripheral surface of the steering shaft 54 which is a shaft inserted through the shaft hole 53. The mounting portion 55 is attached to the inner periphery of the front dash panel 52, and the lip-shaped seal portion 56 is slidably in close contact with the peripheral surface of the steering shaft 54. A bellows portion 57 for coping with shaft eccentricity or the like is integrally provided between the seal portion 56 and the seal portion 56.

  However, this sealing device 51 has the following disadvantages.

  That is, in recent years, this type of sealing device 51 has been demanded to have a higher eccentricity operation. In this respect, in order to follow the high eccentricity only by the shape (elastic deformation) of the bellows portion 57, the bellows portion is required. There are methods such as widening the width of 57 or providing two bellows portions 57. However, according to these methods, there is a possibility that the restriction of the fitting width of the sealing device 51 or the damage due to the contact of the bellows portion 57 may become a problem. is there.

  As a technique related to the present invention, the applicant of the present invention firstly, as shown in FIG. 7, a seal lip 63 that contacts the rotating shaft 62 to prevent fluid leakage, and an inner ring 64 that supports the seal lip 63. And an outer peripheral portion 65 that is provided on the outer peripheral side of the seal lip 63 and supports the seal lip 63, and enables relative movement between the outer peripheral portion 64 and the inner ring 64 at the outer diameter portion of the seal lip 63. According to this prior art, a sealing device 61 having a sliding portion 66 is proposed. Even if the sealing device 61 does not have a bellows portion, the sliding portion 66 is displaced in the radial direction with respect to the outer peripheral portion 65. The seal lip 63 can follow the shaft eccentricity or the like.

  However, according to this prior art, the sliding portion 66 made of a rubber-like elastic body has an inner ring 64 embedded therein, and its axial width is set to be relatively large. When the 66 is displaced in the radial direction with respect to the outer peripheral portion 65, a pressure fluctuation may occur in the inner space 65a of the outer peripheral portion 65, and smooth sliding of the sliding portion 66 may be hindered. A through hole 67 must be provided in the outer peripheral portion 65 to open the internal space 65a to the atmosphere.

JP-A-9-242880 Japanese Utility Model Publication No. 64-55368

  In view of the above, an object of the present invention is to provide a sealing device that can cope with a highly eccentric operation that has been required in recent years and that does not require a through hole in a component.

  In order to achieve the above object, a sealing device according to claim 1 of the present invention includes an attachment portion attached to an inner periphery of a housing through which a shaft is inserted, a bellows portion provided on an inner periphery side of the attachment portion, and the bellows A sealing device provided on a further inner peripheral side of the portion and having a seal portion that is slidably in close contact with the peripheral surface of the shaft, and a rigid plate slide portion is provided radially outward on the outer peripheral side of the bellows portion. The rigid plate slide portion is held slidably in the radial direction by a pair of axial support slide portions provided on the inner peripheral side of the mounting portion. is there.

  According to a second aspect of the present invention, there is provided a sealing device attached to an inner periphery of a housing through which a shaft is inserted, and provided on the inner peripheral side of the mounting portion and in close contact with the peripheral surface of the shaft. In the sealing device having a sealing portion, a pair of axially provided slides made of a rigid plate is integrally held radially outward on the outer peripheral side of the sealing portion, and provided on the inner peripheral side of the mounting portion. The rigid plate slide part is held by a slide support part so as to be slidable in the radial direction.

  The sealing device according to claim 3 of the present invention is the sealing device according to claim 1 or 2, wherein the pair of slide support portions in the axial direction are slidably in close contact with the plane of the slide portion made of a rigid plate. It has a sliding lip-shaped sliding holding part that sandwiches the sliding part from both sides in the axial direction.

  In the sealing device according to the first aspect of the present invention having the above-described configuration, the rigid plate slide portion is integrally held radially outward on the outer peripheral side of the bellows portion, and the rigid plate slide portion is Since it is configured to be slidable in the radial direction by a pair of slide support portions in the axial direction provided on the inner peripheral side of the mounting portion, the bellows portion is elastically deformed when the shaft is eccentric, and the slide portion is also attached. Absorbs the eccentricity by sliding in the radial direction. Accordingly, the eccentric absorption due to the elastic deformation of the bellows and the eccentric absorption due to the slide in the radial direction of the slide are combined, so that it is possible to cope with high eccentricity operation.

  Further, since the sliding portion made of a rigid plate is thinner than the sliding portion 66 made of a rubber-like elastic body in the prior art (as shown in FIG. 7, the sliding portion made of a rubber-like elastic body). If the inner ring 64 made of a rigid plate is embedded in the thickness of the portion 66 and the inner ring 64 made of the same rigid plate and the slide portion of the present invention have the same thickness, It is possible to keep the volume change rate of the space into which this is inserted at the time of sliding small. Therefore, the slide portion can be smoothly slid without providing a through hole in the slide support portion.

  In addition, the above-mentioned “sliding portion made of rigid plate is integrally held radially outward on the outer peripheral side of the bellows portion, and the pair of axially provided sliding portions made of rigid plate is provided on the inner peripheral side of the mounting portion. The configuration in which the slide support portion is held so as to be slidable in the radial direction is also applicable to a type of sealing device that has only a mounting portion and a seal portion and does not have a bellows portion. It is possible to cope with high eccentricity operation by setting the amount large. Therefore, in the sealing device according to claim 2 of the present application, the bellows portion is omitted from the components of the sealing device according to claim 1.

  Further, in common with the first and second aspects, the pair of slide support portions in the axial direction is slidably in close contact with the plane of the slide portion made of a rigid plate, and has a seal lip shape sandwiching the slide portions from both sides in the axial direction. With the configuration having the sliding holding portion, the sliding portion can be stably held and the sealing performance between the sliding portion and the sliding holding portion can be ensured.

  The present invention has the following effects.

  That is, according to the sealing device according to the first aspect of the present invention, the rigid plate slide portion is integrally held radially outward on the outer peripheral side of the bellows portion, and the rigid plate slide portion is attached to the mounting portion. The bellows part is elastically deformed in the event of shaft eccentricity, etc. due to the axially slidable support provided by the pair of slide support parts provided on the inner peripheral side. Slide to absorb eccentricity. Therefore, since the eccentric absorption action by the elastic deformation of the bellows part and the eccentric absorption action by the radial slide of the slide part are performed together, it is possible to cope with a high eccentricity operation.

  Further, since the slide portion made of a rigid plate is relatively thin and the volume change rate of the space into which the slide plate is inserted can be kept small, the slide portion can be provided without providing a through hole in the slide support portion. Slide smoothly.

  According to the sealing device according to claim 2 of the present invention, the rigid plate slide portion is integrally held radially outward on the outer peripheral side of the seal portion, and the rigid plate slide portion is the inner periphery of the mounting portion. Since it is slidable in the radial direction by the pair of axial support slides provided on the side, when the shaft eccentricity occurs, the slide part slides in the radial direction to absorb the eccentricity. Therefore, it is possible to cope with high eccentricity operation by setting the slide amount in the radial direction of the slide part to be large to some extent.

  Further, since the slide portion made of a rigid plate is relatively thin and the volume change rate of the space into which the slide plate is inserted can be kept small, the slide portion can be provided without providing a through hole in the slide support portion. Slide smoothly.

  Furthermore, according to the configuration of the second aspect, since there is no portion that elastically deforms when absorbing eccentricity, early deterioration of parts such as sag can be suppressed, and durability of a sealing device that operates with high eccentricity is improved. be able to.

  Further, according to the sealing device of the third aspect of the present invention, the pair of slide support portions in the axial direction are slidably in close contact with the plane of the slide portion made of a rigid plate so as to sandwich the slide portions from both sides in the axial direction. Since the slide holding portion is provided, the slide portion can be stably held and the sealing performance between the slide portion and the slide holding portion can be ensured.

  The present invention includes the following embodiments.

(1) A sealing device having a shape having a movable part at a place other than the bellows part in order to cope with high eccentricity.
(2) A sealing device having a shape having a slidable part at a place other than the bellows part in order to cope with high eccentricity.
(3) The bellows base at the outer peripheral side is sandwiched with rubber (lip shape) so as to be slidable.
(4) According to the above configurations (1) to (3), the movable portion can be provided at a location other than the expansion and contraction of the bellows portion. Thereby, after the bellows is completely contracted, the sandwiching portion is moved in the lip portion, so that further eccentricity can be followed. The bellows portion may not be provided.

  Next, embodiments of the present invention will be described with reference to the drawings.

First embodiment ...
FIG. 1 shows a cross section of a main part of a sealing device 1 according to a first embodiment of the present invention. The sealing device 1 according to the embodiment is used as a vehicle steering dust seal and is configured as follows. This embodiment is an embodiment according to claims 1 and 3.

  That is, the sealing device 1 firstly forms a radial clearance between the peripheral surface of the shaft hole 3 provided in the front dash panel 2 that is a housing and the peripheral surface of the steering shaft 4 that is a shaft inserted through the shaft hole 3. It has a mounting portion 5 that is attached to the inner periphery of the front dash panel 2 and a sealing portion 6 that is slidably in close contact with the peripheral surface of the steering shaft 4. A bellows portion 7 for coping with shaft eccentricity or the like is integrally formed between the seal portion 6 and the seal portion 6. Further, a rigid plate slide portion 8 is integrally held radially outward on the outer peripheral side of the bellows portion 7, and the rigid plate slide portion 8 is formed on the inner peripheral side of the mounting portion 5. The pair of slide support portions 9 and 10 provided in the axial direction are held so as to be slidable in the radial direction.

  The mounting portion 5 is formed by vulcanizing and bonding rubber-like elastic bodies 12 and 13 to the surface of the metal ring 11 fitted to the inner periphery of the shaft hole 3 of the front dash panel 2. An outer peripheral seal portion 14 that seals between the front dash panel 2 is formed by a part of the rubber-like elastic body 12 that is attached. A part of the rubber ring 13 is also attached to the inner peripheral surface of the metal ring 11, and this rubber-like elastic body 13 allows a gap between the metal ring 17 and the metal ring 17 of the second slide support portion 10 to be described later. An inner peripheral seal portion 15 to be sealed is formed.

  A pair of slide support portions 9 and 10 in the axial direction provided on the inner peripheral side of the attachment portion 5 are obtained by vulcanizing and bonding rubber-like elastic bodies 18 and 19 to the surfaces of the metal rings 16 and 17, respectively. The rubber-like elastic bodies 18 and 19 are formed into sealing lip-like sliding holding portions 20 and 21 that are slidably in close contact with the plane of the rigid plate slide portion 8 and sandwich the slide portion 8 from both sides in the axial direction. Yes. The seal lip-shaped sliding holding portions 20 and 21 are integrally formed with main lips 20a and 21a provided radially inward and sub lips 20b and 21b provided radially outward, respectively. Have.

  The metal ring 16 of the first slide support portion 9 disposed on the upper side in the figure is formed integrally with the metal ring 11 of the attachment portion 5. That is, the radial direction part 16a is integrally formed from the upper end part of the cylindrical part 11a of the metal ring 11 of the attachment part 5 inward in the radial direction and one axial direction from the inner peripheral end part of the radial direction part 16a ( The cylindrical portion 16b is integrally formed downward (in the drawing), and the radial portion 16a and the cylindrical portion 16b constitute the metal ring 16 of the first slide support portion 9, and the cylindrical portion 16b A lip-shaped sliding holding portion 20 is attached to the tip. In addition to the lip-shaped sliding holding portion 20, the rubber-like elastic body 18 is attached to the inner peripheral attached portion 18a attached to the inner peripheral surface of the cylindrical portion 16b and the outer end face of the radial direction portion 16a. The end face adherence part 18b is integrally formed, and the end face adherence part 18b is integrally connected to the outer peripheral seal part 14 of the attachment part 5. Accordingly, the mounting portion 5 and the first slide support portion 9 are molded as one vulcanized molded product (first vulcanized molded product) comprising one metal ring and a rubber-like elastic body attached to the metal ring. Yes.

  On the other hand, the second slide support portion 10 arranged on the upper and lower sides of the figure is composed of a second vulcanized product, and has a metal ring 17 and a rubber-like elastic body 19 vulcanized and bonded thereto. is doing. The metal ring 17 includes an outer peripheral side cylindrical part 17a fitted via an inner peripheral seal part 15 on the inner peripheral side of the cylindrical part 11a of the metal ring 11 of the attachment part 5, and the outer peripheral side cylindrical part 17a. A radial portion 17b integrally formed from the upper end portion inward in the radial direction, and an inner peripheral side tube integrally formed from the inner peripheral end portion of the radial direction portion 17b toward the other axial direction (upward in the drawing) The lip-shaped sliding holding portion 21 is attached to the tip of the inner peripheral cylindrical portion 17c. In addition to the lip-shaped sliding holding portion 21, the rubber-like elastic body 19 includes an inner peripheral attached portion 19a attached to the inner peripheral surface of the inner peripheral cylindrical portion 17c, and an outer end face of the radial portion 17b. And an end face attaching portion 19b attached to the outer surface.

  Between the metal ring 11 of the mounting part 5 and the metal ring 17 of the second slide support part 10, an inner peripheral seal part made of a rubber-like elastic body 13 attached to the inner peripheral surface of the cylindrical part 11 a of the former metal ring 11. 15 is sealed. Between the pair of upper and lower slide support portions 9 and 10, that is, between the lip-shaped slide holding portions 20 and 21, a slide portion 8 made of a rigid plate is sandwiched between them to be sealed. No through-holes are formed in the mounting portion 5 and the upper and lower slide support portions 9 and 10 (first and second vulcanized molded products). Therefore, the space 22 surrounded by the attachment portion 5 and the pair of slide support portions 9 and 10 is airtight and is cut off from the atmosphere, and the space 22 that is airtight and cut off from the air is excellent in sound insulation. Demonstrate the effect.

  The seal portion 6 integrally includes a seal lip 23 slidably in close contact with the peripheral surface of the steering shaft 4, a damper 24 that causes the seal lip 23 to follow the eccentricity of the shaft 4, a beard lip 25, and a grease retaining lip 26. And is integrally formed with a predetermined rubber-like elastic body, and a reinforcing metal ring 27 is embedded in the damper 24.

  The bellows portion 7 is integrally formed radially outward from the outer periphery of the damper 24 of the seal portion 6, and a slide mounting portion that integrally holds a rigid plate slide portion 8 at the outer peripheral end portion thereof. 28 is integrated.

  The rigid plate slide portion 8 is formed in an annular plate shape, and is held integrally with the slide mounting portion 28 with its inner peripheral end portion, and is arranged between a pair of upper and lower slide support portions 9 and 10. And is slidable in the radial direction by being sandwiched between the pair of sliding holding portions 20 and 21.

  The sealing device 1 having the above-described configuration is used as a steering dust seal for a vehicle such as an automobile as described above, and seals this so that dust does not enter from the engine compartment side to the vehicle interior side. It has a feature in that there are operational effects.

  That is, first, as described above, the rigid plate slide portion 8 is integrally held radially outward on the outer peripheral side of the bellows portion 7, and the rigid plate slide portion 8 is the inner peripheral side of the mounting portion 5. Since the shaft 4 is held slidable in the radial direction by the pair of slide support portions 9 and 10 provided in the axial direction, when the shaft 4 is eccentric, the bellows portion 7 is elastically deformed. The slide portion 8 slides in the radial direction to absorb the eccentricity. Therefore, since the eccentric absorption action by the elastic deformation of the bellows portion 7 and the eccentric absorption action by the radial slide of the slide portion 8 are performed together, it is possible to cope with a high eccentricity operation.

  FIG. 2 shows this operating state. Due to the eccentricity of the shaft 4 (arrow A), the seal portion 6 is displaced in the direction approaching the attachment portion 5 on the left side of the drawing. Therefore, the bellows portion 7 is in a state of being compressed in the radial direction, and the slide portion 8 is deeply inserted into the space 22 by being pushed by the bellows portion 7. On the other hand, on the right side of the figure, the seal portion 6 is displaced in a direction away from the mounting portion 5, so that the bellows portion 7 extends in the radial direction and the slide portion 8 is substantially in a fixed position (pulled by the bellows portion 7). And may slide in a direction to leave the space 22).

  Further, in the sealing device 1 having the above-described configuration, the rigid plate slide portion 8 is relatively thin, and the volume change rate of the space 22 into which the slide portion 8 is inserted can be reduced. Even if the through hole is not provided in the part 5 and the upper and lower slide support parts 9 and 10, the slide part 8 slides smoothly. Therefore, the formation process of the through hole can be omitted. Further, as described above, the space 22 is airtight and shielded from the atmosphere, so that an excellent sound insulation effect can be exhibited and the noise on the engine side can hardly be transmitted to the vehicle interior side.

  Further, in the sealing device 1 having the above-described configuration, the pair of slide support portions 9 and 10 in the axial direction are slidably brought into close contact with the plane of the slide portion 8 made of a rigid plate so as to sandwich the slide portion 8 from both sides in the axial direction. Since the slide holding portions 20 and 21 are provided, the slide portion 8 can be stably held and slid smoothly, and the sealing performance between the slide portion 8 and the slide holding portions 9 and 10 is sufficient. Can be secured.

Second embodiment ...
FIG. 3 shows a cross section of the main part of the sealing device 1 according to the second embodiment of the present invention. The sealing device 1 according to the embodiment is used as a vehicle steering dust seal and is configured as follows. This embodiment is an embodiment according to claims 2 and 3.

  That is, the sealing device 1 firstly forms a radial clearance between the peripheral surface of the shaft hole 3 provided in the front dash panel 2 that is a housing and the peripheral surface of the steering shaft 4 that is a shaft inserted through the shaft hole 3. It has a mounting part 5 to be sealed and attached to the inner periphery of the front dash panel 2, and a seal part 6 slidably in close contact with the peripheral surface of the steering shaft 4. Further, a rigid plate slide portion 8 is integrally held radially outward on the outer peripheral side of the seal portion 6, and the rigid plate slide portion 8 is formed on the inner peripheral side of the mounting portion 5. The pair of slide support portions 9 and 10 provided in the axial direction are held so as to be slidable in the radial direction. Unlike the first embodiment, the bellows portion 6 is not provided.

  The mounting portion 5 is formed by vulcanizing and bonding rubber-like elastic bodies 12 and 13 to the surface of the metal ring 11 fitted to the inner periphery of the shaft hole 3 of the front dash panel 2. An outer peripheral seal portion 14 that seals between the front dash panel 2 is formed by a part of the rubber-like elastic body 12 that is attached. A part of the rubber ring 13 is also attached to the inner peripheral surface of the metal ring 11, and this rubber-like elastic body 13 allows a gap between the metal ring 17 and the metal ring 17 of the second slide support portion 10 to be described later. An inner peripheral seal portion 15 to be sealed is formed.

  A pair of slide support portions 9 and 10 in the axial direction provided on the inner peripheral side of the attachment portion 5 are obtained by vulcanizing and bonding rubber-like elastic bodies 18 and 19 to the surfaces of the metal rings 16 and 17, respectively. The rubber-like elastic bodies 18 and 19 are formed into sealing lip-like sliding holding portions 20 and 21 that are slidably in close contact with the plane of the rigid plate slide portion 8 and sandwich the slide portion 8 from both sides in the axial direction. Yes. The seal lip-shaped sliding holding portions 20 and 21 are integrally formed with main lips 20a and 21a provided radially inward and sub lips 20b and 21b provided radially outward, respectively. Have.

  The metal ring 16 of the first slide support portion 9 disposed on the upper side in the figure is formed integrally with the metal ring 11 of the attachment portion 5. That is, the radial direction part 16a is integrally formed from the upper end part of the cylindrical part 11a of the metal ring 11 of the attachment part 5 inward in the radial direction and one axial direction from the inner peripheral end part of the radial direction part 16a ( The cylindrical portion 16b is integrally formed downward (in the drawing), and the radial portion 16a and the cylindrical portion 16b constitute the metal ring 16 of the first slide support portion 9, and the cylindrical portion 16b A lip-shaped sliding holding portion 20 is attached to the tip. In addition to the lip-shaped sliding holding portion 20, the rubber-like elastic body 18 is attached to the inner peripheral attached portion 18a attached to the inner peripheral surface of the cylindrical portion 16b and the outer end face of the radial direction portion 16a. The end face adherence part 18b is integrally formed, and the end face adherence part 18b is integrally connected to the outer peripheral seal part 14 of the attachment part 5. Accordingly, the mounting portion 5 and the first slide support portion 9 are molded as one vulcanized molded product (first vulcanized molded product) comprising one metal ring and a rubber-like elastic body attached to the metal ring. Yes.

  On the other hand, the second slide support portion 10 arranged on the upper and lower sides of the figure is composed of a second vulcanized product, and has a metal ring 17 and a rubber-like elastic body 19 vulcanized and bonded thereto. is doing. The metal ring 17 includes an outer peripheral side cylindrical part 17a fitted via an inner peripheral seal part 15 on the inner peripheral side of the cylindrical part 11a of the metal ring 11 of the attachment part 5, and the outer peripheral side cylindrical part 17a. A radial portion 17b integrally formed from the upper end portion inward in the radial direction, and an inner peripheral side tube integrally formed from the inner peripheral end portion of the radial direction portion 17b toward the other axial direction (upward in the drawing) The lip-shaped sliding holding portion 21 is attached to the tip of the inner peripheral cylindrical portion 17c. In addition to the lip-shaped sliding holding portion 21, the rubber-like elastic body 19 includes an inner peripheral attached portion 19a attached to the inner peripheral surface of the inner peripheral cylindrical portion 17c, and an outer end face of the radial portion 17b. And an end face attaching portion 19b attached to the outer surface.

  Between the metal ring 11 of the mounting part 5 and the metal ring 17 of the second slide support part 10, an inner peripheral seal part made of a rubber-like elastic body 13 attached to the inner peripheral surface of the cylindrical part 11 a of the former metal ring 11. 15 is sealed. Between the pair of upper and lower slide support portions 9 and 10, that is, between the lip-shaped slide holding portions 20 and 21, a slide portion 8 made of a rigid plate is sandwiched between them to be sealed. No through-holes are formed in the mounting portion 5 and the upper and lower slide support portions 9 and 10 (first and second vulcanized molded products). Therefore, the space 22 surrounded by the attachment portion 5 and the pair of slide support portions 9 and 10 is airtight and is cut off from the atmosphere, and the space 22 that is airtight and cut off from the air is excellent in sound insulation. Demonstrate the effect.

  The seal portion 6 integrally includes a seal lip 23 slidably in close contact with the peripheral surface of the steering shaft 4, a damper 24 that causes the seal lip 23 to follow the eccentricity of the shaft 4, a beard lip 25, and a grease retaining lip 26. And is integrally formed with a predetermined rubber-like elastic body, and a reinforcing metal ring 27 is embedded in the damper 24.

  The rigid plate slide portion 8 is formed in an annular plate shape, and its inner peripheral end portion is integrally held on the outer peripheral portion of the damper 24 of the seal portion 6, and a pair of upper and lower slide support portions 9. , 10 and is sandwiched between a pair of sliding holding portions 20, 21 so as to be slidable in the radial direction.

  The sealing device 1 having the above-described configuration is used as a steering dust seal for a vehicle such as an automobile as described above, and seals this so that dust does not enter from the engine compartment side to the vehicle interior side. It has a feature in that there are operational effects.

  That is, first, as described above, the rigid plate slide portion 8 is integrally held radially outward on the outer peripheral side of the seal portion 6, and the rigid plate slide portion 8 is the inner peripheral side of the mounting portion 5. Since the shaft 4 is held slidable in the radial direction by the pair of axially supported slide support portions 9 and 10, when the shaft 4 is eccentric, the slide portion 8 is slid in the radial direction to absorb the eccentricity. . Accordingly, by setting the sliding amount of the slide portion 8 in the radial direction to be large to some extent, it is possible to cope with a highly eccentric operation.

  FIG. 4 shows this operating state. Due to the eccentricity of the shaft 4 (arrow A), the seal portion 6 is displaced in the direction approaching the mounting portion 5 on the left side of the drawing. Therefore, the slide portion 8 is pushed deeply into the space 22 by being pushed by the seal portion 6. On the other hand, on the right side of the figure, the seal portion 6 is displaced in a direction away from the attachment portion 5, so that the slide portion 8 is pulled by the seal portion 6 and slides in a direction to escape from the space 22.

  Further, in the sealing device 1 having the above-described configuration, the rigid plate slide portion 8 is relatively thin, and the volume change rate of the space 22 into which the slide portion 8 is inserted can be reduced. Even if the through hole is not provided in the part 5 and the upper and lower slide support parts 9 and 10, the slide part 8 slides smoothly. Therefore, the formation process of the through hole can be omitted. Further, as described above, the space 22 is airtight and shielded from the atmosphere, so that an excellent sound insulation effect can be exhibited and the noise on the engine side can hardly be transmitted to the vehicle interior side.

  Further, in the sealing device 1 having the above-described configuration, the pair of slide support portions 9 and 10 in the axial direction are slidably brought into close contact with the plane of the slide portion 8 made of a rigid plate so as to sandwich the slide portion 8 from both sides in the axial direction. Since the slide holding portions 20 and 21 are provided, the slide portion 8 can be stably held and slid smoothly, and the sealing performance between the slide portion 8 and the slide holding portions 9 and 10 is sufficient. Can be secured.

  The sealing device 1 according to the first and second embodiments can be variously changed in configuration within the range in which the object of the present invention can be realized. good.

  In the first embodiment, as shown in FIG. 1, the bellows portion 7 has three inclined surfaces indicated by reference numerals 7a, 7b and 7c and two bent portions (radius portions) indicated by reference numerals 7d and 7e in the radial direction. Although the cross-sectional shape is provided alternately, the cross-sectional shape of the bellows portion 7 is not particularly limited. For example, as shown in FIG. 5, two inclined surfaces indicated by reference numerals 7a and 7b and a reference numeral 7d It may have a relatively simple cross-sectional shape provided with one bending portion (rounded portion) shown alternately in the radial direction.

  Moreover, in the said 1st Example, although the rigid-made slide part 8 is shape | molded by flat plate annular shape, as shown in a 2nd Example, the thing provided with the cyclic | annular level | step-difference part 8a may be sufficient.

  Further, the lip-shaped slide holding portions 20 and 21 can increase or decrease the slide amount of the slide portion 8 by adjusting the sliding resistance with respect to the rigid plate slide portion 8.

Sectional drawing of the principal part of the sealing device which concerns on 1st Example of this invention. Explanatory drawing which shows the operating state of the sealing device Sectional drawing of the principal part of the sealing device which concerns on 2nd Example of this invention. Explanatory drawing which shows the operating state of the sealing device Sectional drawing of the principal part of the sealing device which concerns on the other Example of this invention. Sectional drawing of the sealing device which concerns on a prior art example Sectional drawing of the sealing device which concerns on another prior art example

Explanation of symbols

1 Steering dust seal (sealing device)
2 Front dash panel (housing)
3 Shaft hole 4 Steering shaft (shaft)
5 Mounting part 6 Sealing part 7 Bellow part 7a, 7b, 7c Slope 7d, 7e Bending part 8 Slide part 8a Step part 9,10 Slide support part 11, 16, 17, 27 Metal ring 12, 13, 18, 19 Rubber shape Elastic body 14 Outer peripheral seal portion 15 Inner peripheral seal portion 20, 21 Slide holding portion 20a, 21a Main lip 20b, 21b Sub lip 22 Space 23 Seal lip 24 Damper 25 Beard lip 26 Grease holding lip 28 Slide mounting portion

Claims (3)

A mounting part (5) attached to the inner periphery of the housing (2) inserted through the shaft (4), a bellows part (7) provided on the inner peripheral side of the mounting part (5), and the bellows part (7 ) And a sealing device (1) having a sealing portion (6) slidably in close contact with the peripheral surface of the shaft (4),
A rigid plate slide portion (8) is integrally held radially outward on the outer peripheral side of the bellows portion (7),
The slide part (8) made of rigid plate is slidably held in the radial direction by a pair of slide support parts (9) (10) in the axial direction provided on the inner peripheral side of the attachment part (5). Sealing device characterized. A mounting part (5) attached to the inner periphery of the housing (2) inserted through the shaft (4), and provided on the inner peripheral side of the mounting part (5) and slidable on the peripheral surface of the shaft (4) A sealing device (1) having a sealing part (6) in close contact with
A rigid plate slide portion (8) is integrally held radially outward on the outer peripheral side of the seal portion (6),
The slide part (8) made of rigid plate is slidably held in the radial direction by a pair of slide support parts (9) (10) in the axial direction provided on the inner peripheral side of the attachment part (5). Sealing device characterized. The sealing device according to claim 1 or 2,
The pair of slide support portions (9), (10) in the axial direction is in the form of a seal lip that is slidably in close contact with the plane of the rigid plate slide portion (8) and sandwiches the slide portion (8) from both sides in the axial direction. A sealing device comprising a sliding holding portion (20) (21).

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