JP2022070382A - Sealing device - Google Patents

Abstract

To provide a sealing device which can secure a length of a bellows part in a radial direction, accordingly, is high in eccentricity following performance, and achieved in weight reduction, resource saving and the simplification of a manufacturing process.SOLUTION: A sealing device 1 for sealing a clearance between a shaft and a machine body having an opening part which the shaft penetrates comprises: an annular attachment part 10 which is fixed to the opening part so that an internal peripheral face becomes parallel with an axial core of the shaft, and in which engagement grooves 12 being grooves which form a circle with the axial core as a center at the internal peripheral face are formed in two pieces at a specified interval in a direction parallel with the axial core; two lip parts 20, two bumper parts 50 and two bellows parts 30 which tightly contact with an external peripheral face of the shaft, and are arranged at specified intervals in a direction parallel with the axial core; and two outside-diameter engagement parts 40 which exist at external peripheral side end parts of the bellows parts, are integrated with the bellows parts, fit and fixed to the two engagement grooves of the annular attachment part, and arranged at a specified interval in a direction parallel with the axial core.SELECTED DRAWING: Figure 1

Description

The present invention relates to a sealing device. Specifically, the present invention relates to a steering dust seal that seals a penetration portion of a steering shaft in a front dash panel of an automobile, and a sealing device that can be preferably used as a dust seal in other equipment.

The steering shaft of the car penetrates the dash panel that separates the passenger compartment from the engine compartment. Here, the steering shaft transmits the rotation of the steering wheel to the wheels and moves due to vibration or the like during traveling, so that a gap is provided between the steering shaft and the dash panel. A dust cover is provided in the gap between the steering shaft and the dash panel in order to prevent outside air including foreign matter such as dust and noise generated in the engine room from entering the vehicle interior from this gap.

Examples of the conventional dust cover include the sealing device described in Patent Document 1.
Patent Document 1 describes a sealing device for sealing between a relatively movable airframe and a shaft penetrating an opening opened in the airframe, the fixed ring portion fixed to the opening, and the above-mentioned fixed ring portion. A seal lip that is in close contact with the outer peripheral surface of the shaft, a bumper portion formed at the base of the seal lip, a bellows portion formed between the fixed ring portion and the bumper portion, and a bellows portion that can be freely deformed. Described is a sealing device comprising a low friction sliding ring held on the inner circumference of the bumper portion, wherein the low friction sliding ring is reinforced with a metal ring. Further, according to such a sealing device, the low friction sliding ring is not deformed so as to impair the roundness even when subjected to a radial load due to the axial eccentricity, and therefore, the low friction sliding ring is formed. It is stated that good sealing performance is maintained because the seal lip does not come off from the inner circumference of the bumper portion and the close contact state of the seal lip with respect to the outer peripheral surface of the shaft is not impaired.

Japanese Unexamined Patent Publication No. 2010-91077

However, in the sealing device described in Patent Document 1, the second fixed ring portion is arranged on the inner peripheral side of the first fixed ring portion, and the end portion of the second sealed portion is fixed here, so that the first fixed ring portion is fixed. The radial length of the second bellows portion is shorter than that of the second bellows portion. On the other hand, if the length of the second bellows portion in the radial direction can be made longer, the eccentric followability (the performance of ensuring the sealing property of the gap between the shaft and the opening even if the shaft is eccentric) can be further improved. Can be done. Further, in the sealing device described in Patent Document 1, the first fixed ring portion and the second fixed ring portion are made of metal, but if they can be formed of another material or the like, the weight can be further reduced. Further, in the sealing device described in Patent Document 1, the two sealing portions are different, but if they can be made the same, the amount of raw materials can be further reduced and the manufacturing process can be simplified.

An object of the present invention is to solve the above problems. That is, an object of the present invention is to provide a sealing device which has high eccentricity followability because the length of the bellows portion in the radial direction can be secured, and has achieved weight reduction, resource saving, and simplification of the manufacturing process. do.

In order to solve the above problems, the present inventor has diligently studied and completed the present invention.
The present invention is the following (1) to (3).
(1) A sealing device that seals a gap between a shaft and an airframe that is relatively movable with respect to the shaft having an opening through which the shaft penetrates.
An engaging groove that is cylindrical and is fixed to the opening so that the inner peripheral surface is parallel to the axis of the axis and forms a circle with the axis as the center on the inner peripheral surface. However, two resin annular mounting portions are formed at specific intervals in a direction parallel to the axis, and
Two lip portions that are in close contact with the outer peripheral surface of the shaft and are arranged at specific intervals in a direction parallel to the axis.
Two bumper portions arranged at specific intervals in a direction parallel to the axis on the outer peripheral side of each of the two lip portions.
On the outer peripheral side of each of the two bumper portions, two bellows portions made of an elastic material arranged at specific intervals in a direction parallel to the axis, and
At the axial center, which is located at the outer peripheral end of each of the two bellows, is integral with the bellows, fits into and is fixed to each of the two engaging grooves in the annular mounting portion. Two outer diameter engaging parts arranged at specific intervals in parallel directions,
Has a sealing device.
(2) The sealing device according to (1) above, wherein the lip portion, the bumper portion, the bellows portion, and the outer diameter engaging portion are integrated.
(3) The above (1) or (2) further having two low friction sliding portions arranged at specific intervals in a direction parallel to the axis on the inner peripheral side of each of the two bumper portions. The sealing device described in.

According to the present invention, it is possible to provide a sealing device having high eccentricity followability because the length of the bellows portion in the radial direction can be secured, weight reduction, resource saving, and simplification of the manufacturing process.

It is a half cross-sectional view which shows the state which cut in the plane passing through the axis of the preferable aspect in the sealing apparatus of this invention. It is a schematic perspective view which shows the state which cut the annular attachment part of the preferable aspect in the sealing device of this invention in the plane passing through the axis | sealing apparatus.

The present invention will be described.
The present invention is a sealing device that seals a gap between a shaft and a machine body that is relatively movable with respect to the shaft having an opening through which the shaft penetrates, and is cylindrical and has an inner circumference. The surface is fixed to the opening so as to be parallel to the axis of the axis, and an engaging groove, which is a groove forming a circle centered on the axis, is parallel to the axis on the inner peripheral surface. Two resin annular mounting portions formed at specific intervals in the same direction, and two lip portions closely attached to the outer peripheral surface of the shaft and arranged at specific intervals in a direction parallel to the axis. Two bumper portions arranged at specific intervals in a direction parallel to the axis on the outer peripheral side of each of the two lip portions, and parallel to the axial center on the outer peripheral side of each of the two bumper portions. Two bellows made of elastic material arranged at specific intervals in the direction, and two bellows located at the outer peripheral end of each of the two bellows, integrated with the bellows, and two in the annular mounting portion. It is a sealing device having two outer diameter engaging portions arranged at specific intervals in a direction parallel to the axis, which are fitted to and fixed to each of the engaging grooves.
Such a sealing device is also referred to as "the sealing device of the present invention" below.

The sealing device of the present invention is a sealing device that seals the gap between the shaft and the machine body. Here, the airframe has an opening through which the shaft penetrates. In addition, the airframe is movable relative to the axis.
For example, the steering shaft (shaft) of an automobile penetrates the opening of a dash panel (airframe) that separates the vehicle interior and the engine room. The dash panel is movable relative to the steering shaft. Then, the sealing device of the present invention can be provided as a dust cover in the gap between the steering shaft and the dash panel.

The sealing device of the present invention will be described with reference to the drawings.
FIG. 1 is a semi-cross-sectional view showing a preferred embodiment of the sealing device of the present invention, which is cut in a plane passing through the axis ω (center line of the axis).
Although the axis ω is shown in FIG. 1, the axis and the airframe are not shown. In FIG. 1, the shaft is arranged so that its outer peripheral surface is on the inner peripheral side of the lip portion and the bumper portion in the sealing device of the present invention. Further, in FIG. 1, the airframe is arranged on the outer peripheral side of the sealing device of the present invention, and the outer peripheral surface of the annular mounting portion of the sealing device of the present invention is fixed to the inner peripheral surface of the opening in the airframe.

In FIG. 1, B indicates a side where a source of foreign matter or noise such as an engine room exists, and A indicates a space such as a vehicle interior where foreign matter or noise generated on the B side is desired to be prevented from entering. Means the side.

In FIG. 1, the sealing device 1 of the present invention includes an annular mounting portion 10, two lip portions 20, 20', two bellows portions 30, 30', and two outer diameter engaging portions 40, 40'. It has two bumper portions 50, 50'and two low friction sliding portions 60, 60'.
The sealing device of the present invention does not have to have the low friction sliding portions 60, 60', but it is more preferable to have the low friction sliding portions 60, 60' as shown in FIG.

As in the preferred embodiment shown in FIG. 1, it is preferable that the lip portion, the bumper portion, the bellows portion and the outer diameter engaging portion are integrated. These may be molded separately and joined by an adhesive or the like to be integrated, but they may be integrally molded and obtained, and the lip portion, bumper portion, bellows portion and the outside may be integrated. It is preferable that the diameter engaging portion is a continuous body.

The shapes, sizes, etc. of the lip portion, bumper portion, bellows portion, and low friction sliding portion may be the same as those conventionally known.
Further, the material of the lip portion, the bumper portion and the outer diameter engaging portion is not particularly limited, and may be, for example, a conventionally known rubber material. Examples of the rubber material include synthetic rubbers such as nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR), acrylic rubber (ACM), and fluororubber (FKM).
Further, the material of the bellows portion is not particularly limited, and may be a rubber material similar to the lip portion, the bumper portion and the outer diameter engaging portion, or may be an elastic material. Examples of the elastic material include ethylene propylene rubber (EPDM) and chloroprene rubber (CR).

<Circular mounting part>
The annular mounting portion will be described with reference to FIG. 2 in addition to FIG.
FIG. 2 is a schematic perspective view showing a state in which the cylindrical annular mounting portion 10 in the sealing device 1 of the present invention is cut by a plane passing through the central axis of the cylinder. In principle, the central axis of the annular mounting portion 10 coincides with the axis ω in a state where the axis and the machine body are not relatively moving (stopped).

In the state where the shaft and the machine body are not relatively moving (stopped) in the annular mounting portion 10, the inner peripheral surface 10s of the annular mounting portion 10 is relative to the axial center ω in the cross section as shown in FIG. In principle, it is fixed to the opening of the aircraft such as a dash panel so that it is parallel.

As shown in FIGS. 1 and 2, two grooves are formed on the inner peripheral surface 10s of the annular mounting portion 10. Each of these grooves forms a circle centered on the axis ω in a plane in which the direction of the axis ω is the normal direction. Further, these grooves are formed apart in a direction parallel to the axis ω. That is, the two grooves are formed with a specific interval L ₁ in the direction parallel to the axis ω.
The specific interval L ₁ is determined by the radial and axial lengths and the like in the sealing device 1 of the present invention.
These two grooves are also referred to as engagement grooves in the sealing device of the present invention. In FIGS. 1 and 2, these are referred to as engagement grooves 12 and 12'.

The shape and depth of the engaging grooves 12 and 12'are not particularly limited. As will be described in detail later, since the outer diameter engaging portion is fitted and fixed in the engaging grooves 12 and 12', the outer diameter engaging portion can be fitted and the shape and depth can be easily fixed. You will need it. As shown in FIGS. 1 and 2, the groove may have a rectangular cross section. It is preferable that the depth and width of the engaging grooves 12 and 12'are constant in the circumferential direction.

The annular mounting portion 10 is made of resin. Specifically, it is preferably made of nylon (polyamide), polyethylene, polypropylene, polystyrene, vinyl chloride or the like. Therefore, the sealing device of the present invention can be reduced in weight.

The radial and axial lengths of the annular mounting portion 10 are determined by the size, application, and the like of the sealing device 1 of the present invention.

As shown in FIGS. 1 and 2, the annular mounting portion 10 may have a brim 14 at the end on the A side thereof. In this case, it is easy to position the outer peripheral surface of the annular mounting portion 10 when mounting it on the inner peripheral surface of the opening in the machine body.

<Lip part>
The lip portion will be described.
The lip portions 20 and 20'contact the outer peripheral surface of the shaft. Specifically, the tip portions 22 and 22'of the lip portions 20 and 20'are arranged so as to be slidably brought into close contact with the outer peripheral surface of the shaft. Here, the tip portions 22 and 22'of the lip portions 20 and 20'mean the tip portions on the B side of the lip portions 20 and 20'as shown in FIG.

Further, there are two lip portions 20 and 20'(there are two lip portions 20 and 20'), and these are located at the axial center ω as in the case of the engaging portions 12 and 12'described above. They are arranged at specific intervals in parallel directions. This specific interval is preferably the same as the specific interval L ₁ in the above-mentioned two engaging portions 12, 12'.

It is preferable that the two lip portions 20 and 20'are the same. This is because it contributes to resource saving and simplifies the manufacturing process as compared with the case where the two lip portions 20 and 20'are different.

<Bumper part>
The bumper section will be described.
As shown in FIG. 1, the sealing device 1 of the present invention has two bumper portions 50, 50'.

Each of the two bumper portions 50 and 50'is arranged so as to extend from the root of the lip portions 20 and 20'to the A side in the schematic cross-sectional view shown in FIG. The bumper portions 50 and 50'play a role of stabilizing the close contact state of the lip portions 20 and 20'to the axis. The bumper portions 50 and 50'have a substantially conical cylinder shape in which the diameter gradually increases toward the A side from the roots of the lip portions 20 and 20'.
In the preferred embodiment shown in FIG. 1, the bumper portions 50 and 50'are continuous with the lip portions 20 and 20'. It is preferable that these are obtained by integrally molding.

Further, on the inner peripheral surface of the bumper portions 50, 50', the annular ridges 50a, 50a', 50b, 50b' and the annular groove 50c for unevenly fitting with the outer peripheral surfaces of the low friction sliding portions 60, 60' , 50c'is formed. As a result, the low friction sliding portions 60 and 60'are fixed to the inner peripheral surfaces of the bumper portions 50 and 50'.

Further, in the case of the preferred embodiment shown in FIG. 1, ring-shaped metal rings 52, 52'are embedded in the end portions of the bumper portions 50, 50'on the lip portions 20, 20'. The metal rings 52, 52'strengthen the fixing to the inner peripheral surfaces of the bumper portions 50, 50'of the low friction sliding portions 60, 60', and in addition, the shape of the low friction sliding portions 60, 60' is a perfect circle. It also plays a role of holding the friction portion 20 and 20', and further enhances the degree of adhesion of the lip portions 20 and 20'to the shaft.
The metal rings 52 and 52'may be obtained by punching a metal plate (preferably a steel plate such as SPCC) in a washer shape.

The two bumper portions 50 and 50'are arranged side by side at specific intervals in the direction parallel to the axis ω in the cross section as shown in FIG. This specific interval is preferably the same as the specific interval L ₁ in the above-mentioned two engaging portions 12, 12'.

It is preferable that the two bumper portions 50 and 50'are the same. This is because it contributes to resource saving and simplifies the manufacturing process as compared with the case where the two bumper portions are different.

<Low friction sliding part>
The low friction sliding portion will be described.
Although the low friction sliding portion is not an essential component in the sealing device of the present invention, it is preferable that the sealing device of the present invention has the low friction sliding portion.
The sealing device 1 of the present invention shown in FIG. 1 is provided with two low friction sliding portions 60, 60'on the inner peripheral side of the bumper portions 50, 50'.
When the sealing device 1 of the present invention includes the low friction sliding portions 60, 60', it is possible to prevent the outer peripheral surface of the shaft from directly contacting the inner peripheral surface of the bumper portion even if the shaft is largely eccentric. Then, it is possible to prevent the generation of abnormal noise due to the stick-slip phenomenon caused by the sliding between the outer peripheral surface of the shaft and the inner peripheral surface of the bumper portion.

The two low-friction sliding portions 60 and 60'are made of materials such as nylon (polyamide) and PTFE, which have low friction and excellent wear resistance.

The low-friction sliding portions 60, 60'may have a substantially conical cylinder shape, and a large number of lubrication grooves 62, 62'are formed on the inner peripheral surface thereof at equal intervals in the circumferential direction as shown in FIG. ing. Since a lubricant such as grease can be held in the lubricating groove, the generation of abnormal noise due to the stick-slip phenomenon is further suppressed.

Further, unevenness as shown in FIG. 1 is formed on the outer peripheral surfaces of the low friction sliding portions 60, 60', and the annular ridges 50a, 50a formed on the outer peripheral surfaces of the bumper portions 50, 50'. ′, 50b, 50b ′ and the annular grooves 50c, 50c ′ are unevenly fitted. The low friction sliding portions 60, 60'are pressed from both sides in the axial direction by the annular ridges 50a, 50b, 50a', 50b'formed on the outer peripheral surfaces of the bumper portions 50, 50', and the bumper portions 50, 50' It is fixed to the inner peripheral surface.

The inner diameters of the low friction sliding ring portions 60, 60'are slightly larger than the outer diameter of the shaft.

The shapes, sizes, etc. of the low-friction sliding portions 60, 60'other than the above may be the same as those conventionally known.

The two low-friction sliding portions 60, 60'are arranged side by side at specific intervals in a direction parallel to the axis ω in the schematic cross-sectional view shown in FIG. This specific interval is preferably the same as the specific interval L ₁ in the above-mentioned two engaging portions 12, 12'.

It is preferable that the two low friction sliding portions 60 and 60'are the same. This is because it contributes to resource saving and simplifies the manufacturing process as compared with the case where the two low friction sliding portions are different.

<Bello part>
The bellows section will be described.
The sealing device of the present invention has two bellows. In FIG. 1, the sealing device 1 of the present invention has two bellows portions 30 and 30', each of which is arranged on the outer peripheral side of the bumper portions 50 and 50'in the cross section as shown in FIG.
In the case of the preferred embodiment shown in FIG. 1, the bellows portions 30 and 30'are continuous bodies in which the inner peripheral end portions thereof are connected to the outer peripheral end portions of the bumper portions 50 and 50'. It is preferable that these are obtained by integrally molding.
The bellows portion usually has a wavy shape that is convex toward the B side in the cross section as shown in FIG.

Further, the two bellows portions 30, 30'are arranged side by side at specific intervals in a direction parallel to the axis ω in the schematic cross-sectional view shown in FIG. This specific interval is preferably the same as the specific interval L ₁ in the above-mentioned two engaging portions 12, 12'.

It is preferable that the two bellows are the same. This is because it contributes to resource saving and simplifies the manufacturing process as compared with the case where the two bellows are different.

<Outer diameter engaging part>
The outer diameter engaging portion will be described.
The sealing device of the present invention has two outer diameter engaging portions 40, 40'.
The outer diameter engaging portions 40 and 40'are located at the outer peripheral side ends of the bellows portions 30 and 30', respectively. Further, it is integrated with the bellows portions 30 and 30'. The outer diameter engaging portion may be one that is firmly joined to the outer peripheral side end portion of the bellows portion by using an adhesive or the like, but the outer diameter engaging portion and the bellows portion are continuous and integrally. It is preferably obtained by molding.

Each of the outer diameter engaging portions 40 and 40' has a ring shape centered on the axial center ω.

As shown in FIG. 1, each of the outer diameter engaging portions 40 and 40'is fitted and fixed to each of the two engaging grooves 12 and 12'in the annular mounting portion 10. The fixing method is not particularly limited. For example, a convex portion is formed on the inner surface of the engaging grooves 12 and 12', whereas a concave portion into which the protrusion fits is formed on the surface of the outer diameter engaging portions 40 and 40'. When the outer diameter engaging portions 40 and 40'are fitted into the grooves 12 and 12, it is preferable that the convex portions and the concave portions are fitted and fixed. Further, the outer diameter engaging portions 40 and 40'can be fixed to the engaging grooves 12 and 12'in the annular mounting portion 10 by using an adhesive or the like.

Such a sealing device of the present invention can secure the radial length of the bellows portion as compared with, for example, the sealing device described in Patent Document 1. Therefore, eccentricity is high.
In addition, weight reduction, resource saving, and simplification of the manufacturing process have been achieved.

1 Sealing device of the present invention 10 Circular mounting part 10s Inner peripheral surface of the annular mounting part 12, 12'engagement groove 14 Brim 20, 20'Lip part 22, 22' Tip part 30, 30'Bello part 40, 40'Outside Diameter Engagement part 50, 50'Bumper part 52, 52'Metal ring 50a, 50a' 50b, 50b'Arc-shaped ridge 50c, 50c'Annual groove 60, 60'Low friction sliding part 62, 62'Lubrication groove ω axis heart

Claims (3)

A sealing device that seals the gap between a shaft and an airframe that is relatively movable with respect to the shaft having an opening through which the shaft penetrates.
An engaging groove that is cylindrical and is fixed to the opening so that the inner peripheral surface is parallel to the axis of the axis and forms a circle with the axis as the center on the inner peripheral surface. However, two resin annular mounting portions are formed at specific intervals in a direction parallel to the axis, and
Two lip portions that are in close contact with the outer peripheral surface of the shaft and are arranged at specific intervals in a direction parallel to the axis.
Two bumper portions arranged at specific intervals in a direction parallel to the axis on the outer peripheral side of each of the two lip portions.
On the outer peripheral side of each of the two bumper portions, two bellows portions made of an elastic material arranged at specific intervals in a direction parallel to the axis, and
At the axial center, which is located at the outer peripheral end of each of the two bellows, is integral with the bellows, fits into and is fixed to each of the two engaging grooves in the annular mounting portion. Two outer diameter engaging parts arranged at specific intervals in parallel directions,
Has a sealing device. The sealing device according to claim 1, wherein the lip portion, the bumper portion, the bellows portion, and the outer diameter engaging portion are integrated. The sealing device according to claim 1 or 2, further comprising two low friction sliding portions arranged at specific intervals in a direction parallel to the axis on the inner peripheral side of each of the two bumper portions.

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