JP6939427B2 - Seal ring and telescopic shaft - Google Patents

Description

The present invention relates to a seal ring used in an environment exposed to the outside air, and a telescopic shaft used as an intermediate shaft (intermediate shaft) constituting, for example, a steering device of an automobile.

In a steering device for an automobile, a front end portion of a steering shaft having a steering wheel attached to a rear end portion and a pinion shaft constituting a steering gear unit are connected via an intermediate shaft. As the intermediate shaft incorporated in such a steering device, the total length can be expanded and contracted in order to prevent the vibration input from the wheels from being transmitted to the steering wheel during running or in consideration of the workability of assembling to the vehicle body. The structure may be used.

FIG. 6 shows the conventional structure of the telescopic intermediate shaft 1 described in Japanese Patent Application Laid-Open No. 2005-195120. The intermediate shaft 1 includes a hollow cylindrical outer tube 3 having a female spline portion 2 formed on the inner peripheral surface, and an inner shaft 5 having a male spline portion 4 formed on the outer peripheral surface. Then, by engaging the female spline portion 2 and the male spline portion 4 with splines, the outer tube 3 and the inner shaft 5 are combined so as to be able to transmit torque and expand and contract.

Further, in order to prevent foreign matter such as rainwater or muddy water from entering the spline engaging portion between the female spline portion 2 and the male spline portion 4, a seal ring 6 is incorporated in the intermediate shaft 1. The seal ring 6 includes a metal core metal 7 and an elastic material 8 fixed to the core metal 7. Of these, the core metal 7 has a cylindrical fixed cylinder portion 9 and an inward flange portion 10 bent at a right angle inward in the radial direction from the axial end portion of the fixed cylinder portion 9. Such a core metal 7 is attached to the outer tube 3 by externally fitting and fixing the fixing cylinder portion 9 to the outer peripheral surface of the axial end portion of the outer tube 3. The elastic material 8 is fixed to the inner peripheral edge portion of the inward flange portion 10 constituting the core metal 7, and has a seal lip portion 11 whose tip edge is in contact with the outer peripheral surface of the inner shaft 5.

According to the conventional structure as described above, even when the intermediate shaft 1 expands and contracts, the tip edge of the seal lip portion 11 slides in contact with the outer peripheral surface of the inner shaft 5, so that the end opening of the outer tube 3 is closed. be able to. Therefore, it is possible to prevent foreign matter such as rainwater or muddy water from entering the spline engaging portion between the female spline portion 2 and the male spline portion 4.

Japanese Unexamined Patent Publication No. 2005-195120 Japanese Unexamined Patent Publication No. 2003-161331 International Publication No. 2003/031250 Pamphlet

However, in the above-mentioned conventional structure, since most of the metal core metal 7 is exposed to the outside, salt water or muddy water adheres to the outer surface of the core metal 7 when the intermediate shaft 1 is used outside the vehicle interior. Rust is likely to occur on the core metal 7. Further, when rust is generated on the core metal 7, rust is likely to progress to the outer tube 3 in contact with the core metal 7 (so-called rust is likely to occur).

Therefore, as described in Japanese Patent Application Laid-Open No. 2003-161331, it is conceivable to cover the entire surface of the core metal with an elastic material. By adopting such a structure, it is possible to effectively prevent rust from being generated on the core metal and the outer tube. However, when the entire surface of the core metal is covered with an elastic material in this way, the support rigidity of the seal ring with respect to the outer tube becomes low, and it becomes difficult to stabilize the contact state between the seal lip portion and the outer peripheral surface of the inner shaft. ..

The present invention has been made in view of the above circumstances, and an object of the present invention is to realize a seal ring structure capable of preventing rusting of the core metal and ensuring support rigidity for the outer tube. It is to be.

The seal ring of the present invention is incorporated in a telescopic shaft formed by combining a hollow tubular female shaft and a male shaft so as to be able to transmit torque and expand and contract the entire length. It has an elastic material fixed to the core metal.
The core metal includes a fixed cylinder portion that is externally fitted and fixed to the outer peripheral surface of the axial end portion of the female shaft, and an inward flange portion that is bent inward in the radial direction from the axial end portion of the fixed cylinder portion. Have.
The elastic material has a seal lip portion that brings the tip edge into contact with the outer peripheral surface of the male shaft, and does not cover the inner peripheral surface of the fixed cylinder portion, but the outer surface (preferably the outer surface) of the core metal. It covers the whole).
The fact that the inner peripheral surface of the fixed cylinder portion is not covered with the elastic material is not limited to a structure in which the entire inner peripheral surface of the fixed cylinder portion is not covered with the elastic material at all, and is inevitable in manufacturing. A structure in which a part of the inner peripheral surface of the fixed cylinder portion (for example, a portion that does not contact the outer peripheral surface of the female shaft when the seal ring is attached and does not contribute to the support rigidity of the seal ring) is covered with the elastic material. including.

In the seal ring according to the first aspect of the present invention, the fixed cylinder portion provided with a locking piece protruding inward in the radial direction can be used.
Further , the elastic material can cover the cut formed around the locking piece in the fixed cylinder portion and opened on the outer peripheral surface of the fixed cylinder portion from the outside.
In the seal ring according to the second aspect of the present invention, the inward flange portion can be bent at an acute angle with respect to the fixed cylinder portion.

The telescopic shaft of the present invention is attached to a hollow tubular female shaft, a male shaft inserted inside the female shaft, and an axial end portion of the female shaft to close the axial end opening of the female shaft. It is equipped with a seal ring. Then, the female shaft and the male shaft are combined so that torque can be transmitted and the entire length can be expanded and contracted.
In particular, in the telescopic shaft of the present invention, the seal ring of the present invention is used as the seal ring.
In the telescopic shaft of the present invention, a locking piece that protrudes inward in the radial direction provided in the fixed cylinder portion is engaged with a concave portion that is recessed inward in the radial direction provided on the outer peripheral surface of the end portion of the female shaft. Can be made to.
Further, in the telescopic shaft of the present invention, the recess can be provided on the outer peripheral surface of the portion of the female shaft that is axially deviated from the sliding range of the male shaft in the used state.

According to the present invention, it is possible to prevent the core metal from being rusted and to secure the support rigidity for the outer tube (female shaft).

FIG. 1 is a schematic partial cross-sectional view showing an example of a steering device provided with an intermediate shaft according to the first example of the embodiment. FIG. 2 is a partial cross-sectional view showing an intermediate shaft and its peripheral members taken out with respect to the first example of the embodiment. FIG. 3 is an enlarged view of part A of FIG. FIG. 4 is a diagram corresponding to FIG. 3, showing a second example of the embodiment. FIG. 5 is a diagram corresponding to FIG. 3 showing a reference example relating to the present invention. FIG. 6 is a diagram corresponding to FIG. 3, showing an intermediate shaft having a conventional structure.

[First Example of Embodiment]
A first example of the embodiment will be described with reference to FIGS. 1 to 3. In this example, the case where the present invention is applied to an intermediate shaft constituting a steering device for an automobile is shown.

[Overview of steering device]
The steering device for automobiles includes a steering wheel 12, a steering shaft 13, a steering column 14, a pair of universal joints 15a and 15b, an intermediate shaft 1a, a steering gear unit 16, and a pair of tie rods 17. I have.

The steering shaft 13 is rotatably supported inside the steering column 14 supported by the vehicle body. A steering wheel 12 operated by the driver is attached to the rear end portion of the steering shaft 13, and the front end portion of the steering shaft 13 is a steering gear via a pair of universal joints 15a and 15b and an intermediate shaft 1a. It is connected to the pinion shaft 18 of the unit 16. Therefore, when the driver rotates the steering wheel 12, the rotation of the steering wheel 12 is transmitted to the pinion shaft 18 of the steering gear unit 16. The rotation of the pinion shaft 18 is converted into a linear motion of the rack meshed with the pinion shaft 18, pushing and pulling a pair of tie rods 17. As a result, the steering wheel is provided with a steering angle according to the amount of operation of the steering wheel 12. The front-rear direction means the front-rear direction of the vehicle body to which the steering device is assembled. In FIG. 1, the left side corresponds to the front side and the right side corresponds to the rear side, whereas in FIGS. 2 and 3, the left side corresponds to the rear side and the right side corresponds to the front side.

[Overview of intermediate shaft]
The intermediate shaft 1a of this example is used outside the vehicle interior, and has a hollow cylindrical outer tube 3a having a female spline portion 2a formed on the inner peripheral surface and an axial one-end portion (front end portion, which is shown in the figure). It is provided with an inner shaft 5a having a male spline portion 4a formed on the outer peripheral surface of the right end portion of 2). Then, the male spline portion 4a of the inner shaft 5a corresponding to the male shaft is inserted inside the outer tube 3a corresponding to the female shaft, and the male spline portion 4a and the female spline portion 2a are spline-engaged. , The outer tube 3a and the inner shaft 5a are combined so that torque can be transmitted and the entire length can be expanded and contracted.

Further, in this example, the outer tube 3a is arranged on the front side in the front-rear direction of the vehicle body, and the inner shaft 5a is arranged on the rear side in the front-rear direction of the vehicle body. Further, a yoke 19 constituting the universal joint 15a arranged on the front side of the pair of universal joints 15a and 15b is externally fitted and fixed (press-fitted) to one end of the outer tube 3a in the axial direction. On the other hand, at the other end of the inner shaft 5a in the axial direction (the left end in FIG. 2), a yoke 20 constituting the universal joint 15b arranged on the rear side of the pair of universal joints 15a and 15b is externally fitted and fixed. It is (press-fitted). When carrying out the present invention, the positional relationship between the outer tube 3a and the inner shaft 5a in the front-rear direction can be reversed from the case of this example.

[Structure of seal ring]
In this example, a seal ring 6a is incorporated in the intermediate shaft 1a in order to prevent foreign matter such as rainwater or muddy water from entering the spline engaging portion between the female spline portion 2a and the male spline portion 4a. Specifically, the seal ring 6a is attached to the other end in the axial direction of the outer tube 3a to close the opening at the other end in the axial direction of the outer tube 3a.

The seal ring 6a includes a core metal 7a made of a metal plate and an elastic material 8a made of an elastic material such as rubber or an elastomer fixed to the core metal 7a.

Of these, the core metal 7a has a substantially horizontal J-shape in cross section and is formed in an annular shape as a whole. The fixed cylinder portion 9a has an inward flange portion 10a that is bent inward in the radial direction and toward one side in the axial direction from the other end in the axial direction.

The fixed cylinder portion 9a is provided with locking pieces (caulking pieces) 21 protruding inward in the radial direction at a plurality of locations at equal intervals in the circumferential direction. The locking piece 21 is formed by bending the inside of a U-shaped cut 28 having an opening on one side in the axial direction formed in the intermediate portion in the axial direction of the fixed cylinder portion 9a inward in the radial direction, and is formed inward in the radial direction. It is inclined in the direction toward the other side in the axial direction.

In this example, in order to fit the fixed cylinder portion 9a as described above, the small diameter portion 22 has a smaller outer diameter than the portion adjacent to one side in the axial direction on the outer peripheral surface of the other end in the axial direction of the outer tube 3a. Is forming. In the illustrated example, the degree to which the small diameter portion 22 has a smaller outer diameter dimension than the portion adjacent to one side in the axial direction of the small diameter portion 22 is larger than twice the plate thickness of the fixed cylinder portion 9a (core metal 7a). It is slightly smaller.

Further, in the axially intermediate portion of the small diameter portion 22, an annular concave groove 23 having a rectangular cross section recessed inward in the radial direction, which corresponds to a concave portion, is provided over the entire circumference. In this example, such an annular groove 23 is axially aligned with the tapered portion 24 of the inner peripheral surface of the outer tube 3a in which the tip surface of the spline teeth forming the female spline portion 2a is tapered. It is provided in the part (the part that overlaps in the radial direction). That is, the annular groove 23 is provided on the outer peripheral surface of the outer tube 3a that is axially deviated from the sliding range of the male spline portion 4a of the inner shaft 5a under normal use conditions. As a result, the shape change of the inner peripheral surface of the outer tube 3a caused by forming the annular concave groove 23 on the outer peripheral surface of the outer tube 3a causes the expansion and contraction operation (relative to the axial direction) between the outer tube 3a and the inner shaft 5a. It does not affect the displacement). More specifically, by forming the annular groove 23, it is possible to prevent the stroke load between the outer tube 3a and the inner shaft 5a from becoming large.

Then, in this example, the fixed cylinder portion 9a is directly fitted to the small diameter portion 22 by press fitting without interposing another member, and the other half portion in the axial direction of the locking piece 21 is inside the annular groove 23. Is entering. As a result, the other end edge (tip edge) of the locking piece 21 in the axial direction is brought into contact with or close to the side surface of the annular groove 23. Further, a step formed on the axial one end surface (tip surface) of the fixed cylinder portion 9a between the small diameter portion 22 and the portion adjacent to the axial one side of the small diameter portion 22 on the outer peripheral surface of the outer tube 3a. It is in contact with or close to the surface 25.

The inward flange portion 10a is folded back 90 degrees or more (about 150 degrees in the illustrated example) from the other end in the axial direction of the fixed cylinder portion 9a. Therefore, the angle θ formed by the inward flange portion 10a and the fixed cylinder portion 9a is an acute angle. Further, in this example, the bent portion (continuous portion) of the fixed cylinder portion 9a and the inward flange portion 10a is curved in a circular arc shape in cross section. The inner diameter of the inward flange portion 10a is smaller than the outer diameter of the male spline portion 4a on the outer peripheral surface of the inner shaft 5a, and the outer diameter of the small diameter cylindrical surface portion 26 deviating from the male spline portion 4a to the other side in the axial direction. Larger than the diameter. Further, the radial inner end portion of the inward flange portion 10a is located on one side in the axial direction with respect to the other end surface in the axial direction of the outer tube 3a, and enters the inner diameter side of the outer tube 3a.

The elastic material 8a is fixed to the surface of the core metal 7a as described above by vulcanization adhesion, and includes a seal lip portion 11a and a covering portion 27. Of these, the covering portion 27 covers most of the outer surface of the core metal 7a, which is the surface facing the outer space side when attached to the outer tube 3a. Specifically, the covering portion 27 covers the outer peripheral surface of the fixed cylinder portion 9a and the axially other side surfaces of the inward flange portion 10a, respectively, over the entire circumference. Therefore, the covering portion 27 covers the U-shaped cut 28 formed around the locking piece 21 in the fixed cylinder portion 9a and opened on the outer peripheral surface of the fixed cylinder portion 9a from the outside ( It closes the gap due to the cut 28). In addition, in this example, the covering portion 27 also covers the inner peripheral edge portion of the inward flange portion 10a and the axial one side surface of the radial inner end portion of the inward flange portion 10a. On the contrary, of the core metal 7a, the inner peripheral surface of the fixed cylinder portion 9a and the axial one side surface of the inward flange portion 10a other than the inner diameter side end portion are not covered by the covering portion 27, and the core metal 7a Is exposed. Further, in the illustrated example, one end surface (tip surface) in the axial direction of the fixed cylinder portion 9a is in contact with or close to the stepped surface 25 of the outer tube 3a, and most of it is not exposed to the external space. Therefore, it is not covered by the covering portion 27. However, in order to prevent rainwater, muddy water, etc. from entering the gap between the inner peripheral surface of the fixed cylinder portion 9a and the small diameter portion 22, the covering portion 27 also covers one end surface of the fixed cylinder portion 9a in the axial direction. By covering, the entire outer surface of the core metal 7a may be covered by the covering portion 27. Further, the thickness dimension of the covering portion 27 is sufficient if it can exhibit the function of covering the outer surface of the core metal 7a, and can be made thinner than the structure shown in the drawing. Further, the thickness dimension of the covering portion 27 may be the same for the portion covering the fixed cylinder portion 9a and the portion covering the inward flange portion 10a, or may be different from each other.

The seal lip portion 11a has a substantially triangular cross section, and its base end portion is fixed to the radial intermediate portion on the other side surface in the axial direction of the inward flange portion 10a. Further, the seal lip portion 11a is inclined in the direction toward the other side in the axial direction toward the inner side in the radial direction (from the base end portion to the tip end portion), and the tip end edge thereof is included in the outer peripheral surface of the inner shaft 5a. The small-diameter cylindrical surface portion 26 is brought into contact with the small-diameter cylindrical surface portion 26 with a tightening allowance.

The intermediate shaft 1a of this example as described above is intermediate by displaced the outer tube 3a and the inner shaft 5a in the axial direction when vibration is input from the wheels during traveling or when assembling to the vehicle body. The shaft 1a can be expanded and contracted. Further, during such an expansion / contraction operation of the intermediate shaft 1a, the seal ring 6a attached to the other end in the axial direction of the outer tube 3a slides the tip edge of the seal lip portion 11a into the small-diameter cylindrical surface portion 26 of the inner shaft 5. By doing so, the opening at the other end in the axial direction of the outer tube 3a is closed. As a result, by using the intermediate shaft 1a outside the vehicle interior, even if foreign matter such as rainwater or muddy water adheres to the intermediate shaft 1a, such foreign matter will be splined between the female spline portion 2a and the male spline portion 4a. It is possible to effectively prevent invasion to the joint.

In particular, in this example, the outer peripheral surface of the fixed cylinder portion 9a and the axially other side surfaces of the inward flange portion 10a, which are the outer surfaces of the core metal 7a constituting the seal ring 6a, are completely covered by the covering portion 27 constituting the elastic material 8a. It covers the circumference. Therefore, even if foreign matter adheres to the seal ring 6a, it is possible to effectively prevent the core metal 7a from being rusted. Therefore, it is possible to effectively prevent rust from progressing on the outer tube 3a to which the core metal 7a is fitted and fixed. Further, the covering portion 27 that covers the outer peripheral surface of the fixed cylinder portion 9a can effectively prevent foreign substances such as rainwater and muddy water from entering through the U-shaped cut 28.

Moreover, in this example, the inner peripheral surface of the fixed cylinder portion 9a constituting the core metal 7a is not covered by the covering portion 27, and the inner peripheral surface of the fixed cylinder portion 9a is covered by the small diameter portion 22 of the outer tube 3a. On the other hand, it is directly press-fitted without using other members. Therefore, it is possible to sufficiently secure the support rigidity of the seal ring 6a with respect to the outer tube 3a. Therefore, it is possible to stabilize the contact state between the seal lip portion 11a and the small-diameter cylindrical surface portion 26 of the inner shaft 5a.

Further, the locking piece 21 provided on the fixed cylinder portion 9a is allowed to enter the inside of the annular concave groove 23 provided on the outer peripheral surface of the outer tube 3a, and the other end edge (tip edge) of the locking piece 21 in the axial direction is formed. Since it is in contact with or close to the side surface of the annular groove 23, it is possible to effectively prevent the seal ring 6a from coming out from the outer tube 3a to the other side in the axial direction.

Further, since the inner diameter of the inward flange portion 10b is set to be larger than the outer diameter of the small diameter cylindrical surface portion 26 of the inner shaft 5a, the inner shaft 5a is smooth inside the outer tube 3a under normal use conditions. Can be displaced (sliding) to.

On the other hand, when a large force acts on the inner shaft 5a toward the other side in the axial direction, which is the direction of exiting from the inside of the outer tube 3a, during the assembly work of the intermediate shaft 1a, the inner diameter of the inward flange portion 10a becomes male. Since it is smaller than the outer diameter of the spline portion 4a, the radial inner end portion of the inward flange portion 10a and the male spline portion 4a come into contact with each other. Then, a force directed to the other side in the axial direction is applied to the inward flange portion 10a. Here, since the inward flange portion 10a of this example is folded back by 90 degrees or more from the other end in the axial direction of the fixed cylinder portion 9a, the sandwich angle θ between the fixed cylinder portion 9a and the inward flange portion 10a is large. As a result, the bending deformation of the inward flange portion 10a progresses. Then, the inner diameter dimension of the inward flange portion 10a gradually becomes smaller and becomes equal to the outer diameter dimension of the small diameter cylindrical surface portion 26.

When the inner diameter dimension of the inward flange portion 10a becomes equal to the outer diameter dimension of the small diameter cylindrical surface portion 26, the radial inner edge of the inward flange portion 10a comes into contact with (hangs on) the outer peripheral surface of the small diameter cylindrical surface portion 26, and the inward flange portion 10a Bending deformation stops. Then, even when a force directed from the inner shaft 5a to the other side in the axial direction further acts on the inward flange portion 10a, only a compressive force acts on the inward flange portion 10a, and bending deformation does not occur. As a result, it is possible to effectively prevent the inner shaft 5a from coming out from the inside of the outer tube 3a to the other side in the axial direction. As described above, in this example, the seal ring 6a can exert the function of preventing the inner shaft 5a from coming off from the outer tube 3a. In this example, since the locking piece 21 provided on the fixed cylinder portion 9a is inserted into the inside of the annular concave groove 23 provided on the outer peripheral surface of the outer tube 3a, the inner shaft 5a is moved to the inward flange portion 10a. Even when a force directed to the other side in the axial direction is applied, the seal ring 6a does not come out from the outer tube 3a to the other side in the axial direction.

[Second Example of Embodiment]
A second example of the embodiment will be described with reference to FIG. In this example, the shape of the core metal 7b constituting the seal ring 6b is different from the structure of the first example of the embodiment. That is, the inward flange portion 10b constituting the core metal 7b is provided so as to be bent at a right angle inward in the radial direction from the other end in the axial direction of the fixed cylinder portion 9a. That is, the inward flange portion 10b is folded back 90 degrees from the other end in the axial direction of the fixed cylinder portion 9a. Therefore, the radial inner end portion of the inward flange portion 10b is located on the other side in the axial direction with respect to the other end surface in the axial direction of the outer tube 3a, and does not enter the inner diameter side of the outer tube 3a.

However, also in this example, the covering portion 27 constituting the elastic material 8a covers the outer peripheral surface of the fixed cylinder portion 9a and the axially other side surfaces of the inward flange portion 10b, which are the outer surfaces of the core metal 7b. .. Further, in this example, the covering portion 27 also covers the inner peripheral edge portion of the inward flange portion 10b and the axial one side surface of the radial inner end portion of the inward flange portion 10b. On the contrary, of the core metal 7b, the inner peripheral surface of the fixed cylinder portion 9a and the axial inner side surface of the inward flange portion 10b other than the inner diameter side end portion are not covered by the covering portion 27, and the core metal is not covered. 7b is exposed.

In this example as described above, most of the surface of the seal ring 6b exposed to the outside is made of the elastic material 8a, and the core metal 7b is excluded from the axial one end surface of the fixed cylinder portion 9a. Is not exposed to the outside. Therefore, even when foreign matter adheres to the seal ring 6b, it is possible to effectively prevent the core metal 7b from being rusted. Other configurations and effects are the same as in the first example of the embodiment.

[ Reference example ]
A reference example relating to the present invention will be described with reference to FIG. In this reference example, the shape of the core metal 7c constituting the seal ring 6c is different from the structure of both the first example and the second example of the embodiment. That is, the fixed tubular portion 9b constituting the core metal 7c is simply formed in a cylindrical shape, and no locking piece protruding inward in the radial direction is provided. Further, the inward flange portion 10b is provided so as to be bent at a right angle inward in the radial direction from the other end in the axial direction of the fixed cylinder portion 9b, as in the second example of the embodiment.

However, also in this reference example, the covering portion 27 constituting the elastic material 8a covers the outer peripheral surface of the fixed cylinder portion 9b and the axially other side surfaces of the inward flange portion 10b, which are the outer surfaces of the core metal 7c. There is. Further, in this reference example, the covering portion 27 also covers the inner peripheral edge portion of the inward flange portion 10b and the axial one side surface of the radial inner end portion of the inward flange portion 10b. On the contrary, of the core metal 7c, the inner peripheral surface of the fixed cylinder portion 9b and the axial one side surface of the inward flange portion 10b other than the inner diameter side end portion are not covered by the covering portion 27, and the core metal is not covered. 7c is exposed.

Even in this reference example as described above, most of the surface of the seal ring 6c exposed to the outside is made of the elastic material 8a, and the core metal is removed except for one end surface in the axial direction of the fixed cylinder portion 9b. 7c is not exposed to the outside. Therefore, even if foreign matter adheres to the seal ring 6c, it is possible to effectively prevent the core metal 7c from being rusted. Further, in this reference example, it is not necessary to provide an annular concave groove for engaging the locking piece on the outer peripheral surface of the outer tube 3b. Other configurations and effects are the same as in the first example of the embodiment.

The telescopic shaft incorporating the seal ring of the present invention includes a female shaft having a female spline portion formed on the inner peripheral surface and a male having a male spline portion formed on the outer peripheral surface, as in the structure of each example of the embodiment. The shaft is not limited to a structure in which a female spline portion and a male spline portion are spline-engaged and torque can be transmitted and can be expanded and contracted. For example, as described in the pamphlet of International Publication No. 2003/031250, intermediate members such as balls and rollers are arranged between the inner peripheral surface of the female shaft and the outer peripheral surface of the male shaft, and these female shafts and male shafts are placed. A structure in which the shaft and the shaft are combined so that torque can be transmitted and can be expanded and contracted is also applicable. Further, the telescopic shaft incorporating the seal ring of the present invention includes not only a structure that can be expanded and contracted under normal use conditions, but also a structure that can be expanded and contracted when an excessive force such as a secondary collision is applied. ..

1, 1a Intermediate shaft 2, 2a Female spline part 3, 3a, 3b Outer tube 4, 4a Male spline part 5, 5a Inner shaft 6, 6a, 6b, 6c Seal ring 7, 7a, 7b, 7c Core metal 8, 8a Elastic material 9, 9a, 9b Fixed cylinder part 10, 10a, 10b Inward flange part 11, 11a Seal lip part 12 Steering wheel 13 Steering shaft 14 Steering column 15a, 15b Universal joint 16 Steering gear unit 17 Tie rod 18 Pinion shaft 19 York 20 Yoke 21 Locking piece 22 Small diameter part 23 Circular concave groove 24 Tapered part 25 Step surface 26 Small diameter cylindrical surface part 27 Covering part 28 Cut

Claims (6)

A seal ring incorporated into a telescopic shaft formed by combining a hollow cylindrical female shaft and a male shaft so that torque can be transmitted and the entire length can be expanded and contracted.
A metal core and an elastic material fixed to the core are provided.
The core metal includes a fixed cylinder portion that is externally fitted and fixed to the outer peripheral surface of the axial end portion of the female shaft, and an inward flange portion that is bent inward in the radial direction from the axial end portion of the fixed cylinder portion. Have and
The fixed cylinder portion is provided with a locking piece protruding inward in the radial direction.
It said elastic member has a sealing lip contacting the distal edge to the outer peripheral surface of said male shaft, covering the outer surface of the metal core without covering the inner circumferential surface of the fixed cylinder portion Utotomoni, A cut formed around the locking piece in the fixed cylinder portion and opened on the outer peripheral surface of the fixed cylinder portion is covered from the outside.
Seal ring. The seal ring according to claim 1, wherein the angle formed by the inward flange portion and the fixed cylinder portion is an acute angle. A seal ring incorporated into a telescopic shaft formed by combining a hollow cylindrical female shaft and a male shaft so that torque can be transmitted and the entire length can be expanded and contracted.
A metal core and an elastic material fixed to the core are provided.
The core metal includes a fixed cylinder portion that is externally fitted and fixed to the outer peripheral surface of the axial end portion of the female shaft, and an inward flange portion that is bent inward in the radial direction from the axial end portion of the fixed cylinder portion. Have and
The angle formed by the inward flange portion and the fixed cylinder portion is an acute angle.
The elastic material has a seal lip portion that brings the tip edge into contact with the outer peripheral surface of the male shaft, and covers the outer surface of the core metal without covering the inner peripheral surface of the fixed cylinder portion.
Seal ring. A hollow tubular female shaft, a male shaft inserted inside the female shaft, and a seal ring attached to the axial end of the female shaft to close the axial end opening of the female shaft are provided. A telescopic shaft that combines a female shaft and the male shaft so that torque can be transmitted and the entire length can be expanded and contracted.
A telescopic shaft in which the seal ring is the seal ring according to any one of claims 1 to 3. The fixed cylinder portion is provided with a locking piece that protrudes inward in the radial direction, and the locking piece is recessed inward in the radial direction provided on the outer peripheral surface of the end portion of the female shaft. The telescopic shaft according to claim 4 , which is engaged with a recess. The telescopic shaft according to claim 5 , wherein the recess is provided on the outer peripheral surface of a portion of the female shaft that is axially deviated from the sliding range of the male shaft in the used state.

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