TWI606201B - Sealing member - Google Patents

Description

Sealing member

The present invention relates to a sealing member.

For example, in the front fork, an annular dust seal is provided between the outer tube and the inner tube in order to prevent the intrusion of dust. In recent years, it has been developed to prevent dust and the like from entering the inside of the fork even when used in a severe use environment such as off-road of a general road.

As such a dustproof seal, there is a dustproof seal that is fixed to the outer tube and has a main lip and a sub-lip. The main lip and the auxiliary lip are obliquely extended toward the inner tube side of the outer tube which can be advanced and retracted, and are slidably attached to the outer circumference of the inner tube. In such a dust seal, even if the dust is completely scraped off by the main lip portion on the air side of the sub-lip portion, the dust that has not been scraped off is scraped off by the sub-lip portion, thereby preventing the intrusion of dust. Such a dustproof seal is disclosed, for example, in JP2005-308204A.

The dust seal is configured, for example, to allow the dust adhering to the outer circumference of the inner tube to be scraped off when the inner tube enters the outer tube. In this case, the cooperating fluid film is thinned in the field where the inner tube enters the outer tube, and conversely, when the inner tube is withdrawn from the outer tube, the fluid film is thickened to facilitate the passage of the actuating fluid.

Therefore, in this case, the actuating fluid passes through the dustproof seal at the exit stroke of the inner tube, although it is scraped off to the atmosphere side only a small amount each time. In this case, since the flow of the actuating fluid is minute, the function of the fork is not adversely affected, but it is desirable to prevent the flow of the actuating fluid.

Further, when the working fluid is scraped off to the atmosphere side, the dust existing on the atmosphere side is immersed in the scraped working fluid and firmly adheres to the inner tube, which may cause dust to enter the inside.

In view of the above problems, the present invention provides a sealing member which can prevent the flow of the actuating fluid to the outside and prevent the intrusion of dust.

A sealing member according to an aspect of the present invention is a sealing member comprising: an annular base portion surrounded by a shaft member that is inserted into the tubular member in a retractable manner, and is disposed on an inner circumference of the base portion and extends obliquely to the atmosphere side and is slidably coupled to An annular main lip portion on the outer circumference of the shaft member, an annular auxiliary lip portion which is disposed on the inner side of the base portion and which is disposed on the sealing side of the main lip portion and extends obliquely toward the atmosphere side, the main lip portion and the auxiliary lip portion At least one of the inner circumferential surfaces includes an inclined surface extending from the base portion, and a projection surface that protrudes toward the shaft member side from the inclined surface and is slidably attached to the outer circumference of the shaft member.

1‧‧‧ Sealing member

2‧‧‧Inside

2a‧‧‧Sliding surface

2b‧‧‧Sliding surface

2c‧‧‧Sliding surface

3‧‧‧External management

3a‧‧‧ recess

4‧‧‧ base

4a‧‧‧ Body Department

4b‧‧‧Flange

4c‧‧‧core rod

5‧‧‧Dust seals

6‧‧‧Main lip

6a‧‧‧Sloping surface

6b‧‧‧ sloped surface

7‧‧‧Deputy lip

8‧‧‧ inner circumference

8a‧‧‧Face

8b‧‧‧Face

9‧‧‧Fluid seals

10‧‧‧ Front fork

11‧‧‧ bearing

12‧‧‧ bearing

13‧‧‧ damper

14‧‧‧ piston rod

15‧‧‧ cylinder

16‧‧‧ hanging spring

100‧‧‧Dust seals

101‧‧‧Main lip

102‧‧‧Deputy lip

103‧‧‧ sloped surface

104‧‧‧Sloping surface

105‧‧‧Sloping surface

106‧‧‧Sloping surface

200‧‧‧ main lip

201‧‧‧Face

300‧‧‧ Sealing members

309‧‧‧Fluid seals

A1‧‧‧section angle

A2‧‧‧section angle

B1‧‧‧section angle

B2‧‧‧section angle

C1‧‧‧section angle

C2‧‧‧section angle

D1‧‧‧section angle

D2‧‧‧section angle

E1‧‧‧section angle

E2‧‧‧section angle

Fig. 1 is a longitudinal sectional view of a front fork of the embodiment.

Figure 2 is an enlarged longitudinal sectional view of the sealing member of Figure 1.

Fig. 3 is an enlarged longitudinal sectional view showing the main lip portion of the embodiment.

Fig. 4 is an enlarged longitudinal sectional view showing the auxiliary lip portion of the embodiment.

Fig. 5 is an enlarged longitudinal sectional view showing a main lip portion of another embodiment.

Fig. 6 is a longitudinal sectional view showing a sealing member of another embodiment.

Fig. 7 is an enlarged longitudinal sectional view showing a dust seal of a comparative example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same symbols used between different drawings represent the same part or corresponding part.

As shown in FIGS. 1 and 2, the sealing member 1 of the present embodiment is used for the front fork 10. The front fork 10 includes an annular outer tube 3 and an annular inner tube 2 that is movably inserted into the outer tube 3 in the axial direction. The sealing member 1 is inserted into the inner tube 2 which is a tube member outside the tube member as a shaft member, and the outer tube 2 is sealed at the outer periphery. The sealing member 1 includes an annular base portion 4 surrounding the inner tube 2, and an annular main lip portion 6 which is provided on the inner circumference of the base portion 4 and extends obliquely to the atmosphere side and is slidably attached to the outer circumference of the inner tube 2, and is juxtaposed on the inner circumference of the base portion 4 The annular auxiliary lip portion 7 is provided on the sealing side of the main lip portion 6 and extends obliquely toward the main lip portion 6.

The front fork 10 further includes annular bearings 11, 12 and a damper 13. The bearing 11 is attached to the inner circumference of the outer tube 3 and is slidably attached to the outer circumference of the inner tube 2. The bearing 12 is attached to the outer circumference of the inner tube 2 and is slidably attached to the inner circumference of the outer tube 3. The damper 13 is housed in the inner tube 2 and the outer tube 3. The damper 13 is provided with a cylinder 15 having a lower end attached to the bottom of the outer tube 3 in FIG. 1 , a piston (not shown) slidably inserted into the cylinder 15 and dividing the cylinder 15 into two pressure chambers, and one end connected to the piston and illustrated in the figure. The piston rod 14 which is attached to the top of the inner tube 2 at the upper end exerts a predetermined damping force during expansion and contraction. Therefore, if the front fork 10 expands and contracts, the damper 13 also expands and contracts, so that the damping force for preventing the expansion and contraction of the front fork 10 is exerted. Further, a suspension spring 16 is interposed between the cylinder 15 and the inner tube 2. The front fork 10 is constantly pushed by the suspension spring 16 in the direction of elongation. Thereby, the vehicle body can be elastically supported when the front fork 10 is applied to a two-wheeled vehicle or the like.

The damper 13 may be such that the cylinder 15 is attached to the inner tube 2, and the piston rod 14 is attached to the outer tube 3. Further, in the front fork 10, the inner tube 2 may be disposed below, and the outer tube 3 may be disposed above.

The sealing member 1 is provided at the open end of the outer tube 3, and when the inner tube 2 enters the outer tube 3, the dust adhering to the inner tube 2 is scraped off to prevent intrusion into the inside of the front fork 10.

Hereinafter, the configuration of the sealing member 1 will be described in detail.

As shown in Fig. 2, the base portion 4 includes an annular main body portion 4a extending in the axial direction, an annular flange 4b projecting outward from the upper end of the main body portion 4a in the outer circumferential direction, and is provided in the main body portion 4a and the flange 4b. The L-shaped core rod 4c.

As shown in Fig. 2, the main lip portion 6 is inclined from the upper end in the inner periphery of the main body portion 4a toward the upper side in the drawing, that is, on the atmospheric side, and extends toward the inner peripheral side, and is slid to the outer circumference of the inner tube 2 at the front end. Further, the inner diameter of the main lip portion 6 is smaller than the outer diameter of the inner tube 2. Thereby, the inner tube 2 can be clamped by the main lip portion 6 by the repulsive force generated when returning from the bent state.

As shown in Fig. 2, the sub-lip portion 7 is inclined from the lower side toward the atmospheric side in the lower side of the main lip portion 6 of the inner portion of the main body portion 4a while extending toward the inner peripheral side, so as to be provided on the inner peripheral surface 8 of the auxiliary lip portion 7, The protruding surface 8b is slidably attached to the outer circumference of the inner tube 2.

As shown in Fig. 4, an inclined surface 8a and a projection surface 8b are provided on the inner circumferential surface 8. The inclined surface 8a extends from the base portion 4 and is inclined toward the atmosphere side in a manner of gradually reducing the diameter. The protruding surface 8b is formed on the inner peripheral side of the inner peripheral surface 8 from the inclined surface 8a toward the inner peripheral side, that is, the inner tube 2 (shaft member) The side of the side protrusion. The projection surface 8b has an arc shape in cross section.

The projection surface 8b may be any portion that is slidably attached to the inner tube 2 of the inner circumferential surface 8, regardless of where it is placed. However, the portion on the front end side of the projection surface 8b becomes a functionally unnecessary portion, and therefore the projection surface 8b is preferably provided at the front end.

The minimum inner diameter of the projection surface 8b is at least smaller than the outer diameter of the inner tube 2. Thereby, the inner tube 2 can be clamped by the sub-lip portion 7 by the repulsive force generated when returning from the bent state.

Further, since the auxiliary lip portion 7 is provided with the projection surface 8b on the inner peripheral surface 8, the amount of bending of the sub-lip portion 7 is increased by the portion of the projection surface 8b, and as the repulsive force is increased, the surface pressure is increased. When the surface pressure is increased, the clamping force of the auxiliary lip portion 7 is increased, and the followability to the inner tube 2 is increased, and the intrusion of dust due to the opening can be prevented.

In the present embodiment, as shown in FIG. 2, a dust depositing portion which is a space having a U-shaped cross section is formed between the base portion 4 and the main lip portion 6 and the sub-lip portion 7. The dust accumulation portion can deposit dust that has passed through the main lip portion 6 but is scraped off by the auxiliary lip portion 7, thereby preventing dust from entering the inside of the front fork 10.

Moreover, as shown in FIG. 2, the outer tube 3 is provided with the recessed part 3a in the inner periphery of the opening end part.

The body portion 4a is pressed into the recess 3a in the sealing member 1 in such a manner that the flange 4b abuts against the upper end of the outer tube 3. The core rod 4c is provided in the main body portion 4a and the flange 4b. Therefore, when the main body portion 4a is pressed into the concave portion 3a of the outer tube 3 and the base portion 4 is fixed to the outer tube 3, the sealing member 1 is firmly fixed to the outer tube. 3. Further, the main body portion 4a is firmly adhered to the inner side of the concave portion 3a of the outer tube 3, and the flange 4b is also firmly adhered to the end portion of the outer tube 3, and the sealing member 1 seals the inner circumference of the outer tube 3. Next, after the inner tube 2 is inserted into the inner peripheral side inner tube of the sealing member 1, the main lip portion 6 and the sub-lip portion 7 are bent, the outer circumference of the inner tube 2 is clamped, and the outer circumference of the inner tube 2 is sealed. In the above When the inner tube 2 is inserted into the inner peripheral side of the sealing member 1, the cross-sectional angle between the main lip portion 6 and the sub-lip portion 7 and the inner tube 2 is as follows.

As shown in Fig. 3, the cross-sectional angle c1 between the inclined surface 6a on the atmospheric side of the main lip portion 6 of the main lip portion 6 and the sliding surface 2a on the outer circumference of the inner tube 2 to which the main lip portion 6 is slid is set to be The cross-sectional angle c2 between the inclined surface 6b on the sealing side of the main lip portion 6 and the sliding surface 2a is large.

When the cross-sectional angle is larger, the absolute value of the surface pressure gradient value becomes higher at the entry stroke of the inner tube 2, so that the effect of scraping off the active fluid adhering to the outer circumference of the inner tube 2 is improved. Therefore, by setting the cross-sectional angle c1 on the atmospheric side to be larger than the cross-sectional angle c2 on the seal side, it is possible to prevent dust from entering the atmosphere, that is, the outside together with the actuating fluid, during the entry stroke of the inner tube 2.

As shown in Fig. 4, the projection surface 8b which is slidably attached to the outer periphery of the inner tube 2 on the atmospheric side in the auxiliary lip portion 7 is formed in a circular arc shape. Since the distance between the arc and the center of the circle is completely equal, if the projection surface 8b on the circular arc abuts against the inner tube 2, the cross-sectional angle between the arc and the inner tube 2 becomes equal on the atmospheric side and the sealing side. Therefore, the cross-sectional angle d1 between the projection surface 8b on the atmosphere side and the sliding surface 2b on the outer circumference of the inner tube 2 and the cross-sectional angle d2 between the projection surface 8b on the sealing side and the sliding surface 2b on the outer circumference of the inner tube 2 can be The difference is eliminated or the difference is minimal.

When the difference in the cross-sectional angle is small, the difference between the absolute values of the maximum surface pressure gradient values of the convex surface 8b on the atmospheric side and the sealing side becomes small. As a result, the difference between the thickness of the active fluid and the thickness of the active fluid at the time of the exit stroke of the inner tube 2 in the projection surface 8b of the sub-lip portion 7 becomes small. Therefore, the actuating fluid moving to the atmosphere side during the exit stroke of the inner tube 2 returns to the sealing side at the entry stroke of the inner tube 2, and the flow of the actuating fluid to the outside can be prevented.

Although the cross-sectional shape of the projection surface 8b may take a shape other than an arc shape, the surface pressure generated when the lip portion bounces and rebounds due to the entry of the inner tube 2 is not concentrated in the arc shape. one place. Therefore, there is an advantage that it is easy to break and it is easy to make the difference of the absolute value of the surface pressure gradient value small on the atmospheric side and the sealing side.

A fluid seal 9 for preventing leakage of the operating fluid from the front fork is provided in the lower portion of the sealing member 1 in the recess 3a of the outer tube 3. For the actuating fluid used in this specification, a working oil, water, an aqueous solution, an electrically viscous fluid, a magnetic viscous fluid, or the like can be applied to the front fork and other dampers.

Hereinafter, the operation of the sealing member 1 of the present embodiment will be described together with a comparative example.

Fig. 7 is an enlarged cross-sectional view showing the dust seal 100 of the comparative example. The dustproof seal 100 is a dustproof seal of a comparative example, that is, a dustproof seal as disclosed in JP2005-308204A. The cross-sectional angles a1 and b1 are the sliding surfaces of the inner tube 2 and the inner lip portion 101 and the sub-lip portion 102 which are respectively slidably connected to the main lip portion 101 and the sub-lip portion 102 as the sliding surfaces of the inner tube 2 of the shaft member. The angle between the sections. The cross-sectional angles a2 and b2 are the cross-sectional angles between the inclined faces 104 and 106 on the inner side of the main lip portion 101 and the sub-lip portion 102 and the sliding surface. In the dust seal 100, in order to scrape off the dust adhering to the inner tube 2, the cross-sectional angles a1 and b1 are set to be larger than the cross-sectional angles a2 and b2, respectively.

If the section angle is made large, the absolute value of the surface pressure gradient value will become high. Therefore, in the dust seal 100, the absolute value of the surface pressure gradient value of the inclined surfaces 103 and 105 on the atmosphere side can be made higher than the absolute value of the surface pressure gradient value of the inclined surfaces 104 and 106 on the inner side of the fork.

Further, if the absolute value of the surface pressure gradient value is higher, the effect of scraping off the active fluid film adhering to the outer circumference of the inner tube 2 is also improved.

That is, when the dust seal 100 is inserted into the outer tube 3, the dust adhering to the outer circumference of the inner tube 2 is easily scraped off and the fluid film is thinned. Conversely, in the inner tube 2 When the outer tube 3 is withdrawn, the fluid film becomes thicker in order to easily allow the passage of the actuating fluid.

Therefore, in the dust seal 100, when the fluid is passed through the dust seal 100 at the exit stroke of the inner tube 2, it is scraped off to the atmosphere side even though it is a small amount.

Further, when the actuating fluid is scraped off to the atmosphere side, dust existing on the atmosphere side is immersed in the scraped working fluid, and is firmly adhered to the inner tube 2 to allow dust to enter the inside.

In the sealing member 1 of the present embodiment, since the inner diameters of the main lip portion 6 and the auxiliary lip portion 7 are smaller than the outer diameter of the inner tube 2, the main lip portion 6 and the sub-lip portion 7 are bent after the inner tube 2 is inserted. The curved main lip portion 6 and the auxiliary lip portion 7 are intended to restore the bent portion and generate a repulsive force. By this repulsive force, the main lip portion 6 and the sub-lip portion 7 have a clamping force that clamps the inner tube 2.

By the clamping force, the main lip portion 6 and the sub-lip portion 7 are in close contact with the inner tube 2, and the dust adhering to the outer circumference of the inner tube 2 is scraped off during the advancement and retraction stroke of the inner tube 2 to the outer tube 3.

Further, the fluid seal 9 integrally formed in the sealing member 1 scrapes off the active fluid adhering to the inner tube 2.

Further, since the auxiliary lip portion 7 is provided with the projection surface 8b on the inner peripheral surface 8, the amount of bending of the sub-lip portion 7 is increased by the portion of the projection surface 8b, and the repulsive force is increased by the restoration, and the surface pressure of the sub-lip portion 7 is increased. . As a result, the intrusion of dust due to the opening of the auxiliary lip portion 7 can be prevented, the function of scraping the dust can be improved, and the actuating fluid film can be made thinner when the inner tube 2 is withdrawn from the stroke, thereby preventing the actuating fluid from going to the outside. Flow out. Therefore, with the sealing member 1, the flow of the actuating fluid to the outside can be prevented, and the intrusion of dust can be prevented.

The front fork 10 may be externally input from the lateral direction in order to support the wheel and thus bent. As a result, the inner tube 2 may be eccentric with respect to the outer tube 3. Used in such a situation The front fork 10 is provided with the configuration of the present embodiment of the sealing member 1. Since the main lip portion 6 or the sub-lip portion 7 is formed with the projection surface 8b, the clamping force for clamping the inner tube 2 can be improved. Therefore, in view of the eccentricity of the inner tube 2, the lip also follows, which prevents the intrusion of dust and the outflow of the actuating fluid.

Therefore, the sealing member 1 is extremely suitable for the front fork 10, and the use of the front fork 10 can surely prevent the intrusion of dust into the front fork 10 and the flow of the operating fluid.

However, the sealing member 1 of the present embodiment is not limited to the front fork, and may be used for other dampers such as a hydraulic damper for a four-wheeled vehicle.

Further, in the present embodiment, the protrusion surface 8b is provided only in the sub-lip portion 7, but the main lip portion 6 may be provided with the same protrusion surface as the protrusion surface 8b instead of the sub-lip portion 7 as shown in Fig. 5 . 201. Further, protrusion surfaces 8b and 201 may be provided on both the main lip portion 6 and the sub-lip portion 7, respectively.

As shown in Fig. 5, in the case where the main lip portion 200 is provided with the projection surface 201, similarly to the case of the sub-lip portion 7, the surface pressure can be increased to prevent the entry of dust due to the opening.

Further, in this case, the difference between the cross-sectional angle e1 between the projection surface 201 on the atmosphere side and the sliding surface 2c on the outer circumference of the inner tube 2 and the cross-sectional angle e2 between the projection surface 201 and the sliding surface 2c on the seal side may be extremely small. . Therefore, the difference in the thickness of the active fluid film between the atmosphere side and the sealing side can be reduced, and the effect of preventing the flow of the actuating fluid to the outside can be exhibited.

Further, as shown in FIG. 6, a fluid seal 309 may be provided in the sealing member 300 in addition to the dust seal 5. The fluid seal 309 is annular, and a groove portion is provided on the outer peripheral side. The groove portion is fitted into the annular ring spring to increase the clamping force of the fluid seal 309.

As shown in FIG. 6, in the case where the fluid seal 309 is provided on the opposite side of the main lip portion 6 on the inner circumference of the base portion 4 of the sealing member 300, not only one sealing member 300 can actuate the fluid It is sealed with both sides of the dust, and it is only necessary to assemble the sealing member 300 at the time of assembly. Therefore, the trouble of attaching the fluid seal 309 and the dust seal 5 to the open end of the outer tube 3 can be omitted. Further, the fluid seal 309 is not particularly limited to the shape of the fluid seal 309 of the present embodiment shown in FIG. 6 as long as it is generally used by a user.

The embodiment of the present invention has been described above, but the above embodiment is only a part of the application example of the present invention, and is not intended to limit the technical scope of the present invention to the specific configuration of the above embodiment.

The present application claims priority based on Japanese Patent Application No. 2014-258223, filed on Dec. 22, 2011, the entire entire entire entire entire entire entire entire content

1‧‧‧ Sealing member

2‧‧‧Inside

3‧‧‧External management

10‧‧‧ Front fork

11‧‧‧ bearing

12‧‧‧ bearing

13‧‧‧ damper

14‧‧‧ piston rod

15‧‧‧ cylinder

16‧‧‧ hanging spring

Claims (5)

A sealing member comprising: an annular base portion surrounded by a shaft member that is inserted into a tubular member in a retractable manner, and an annular main lip that is provided on an inner circumference of the base portion and that extends obliquely to the atmosphere side and that is slidably attached to an outer circumference of the shaft member And an annular sub-lip portion that is disposed on the inner side of the base portion and that is disposed on the sealing side of the main lip portion and that extends obliquely toward the atmosphere side, wherein at least one of the main lip portion and the sub-lip portion has an inner peripheral surface The inclined surface on which the base portion extends is protruded from the inclined surface toward the shaft member side and is slidably attached to the outer peripheral surface of the shaft member; when the protruding surface is slidably attached to the outer circumference of the shaft member, the protruding surface and the shaft member are The cross-sectional angle between the outer peripheral faces is equal to the sealed side on the atmospheric side. The sealing member according to claim 1, wherein the projection surface that is slidably attached to the outer circumference of the shaft member is formed in a circular arc shape. The sealing member according to claim 1, wherein a cross-sectional angle between an inclined surface on the atmosphere side of the main lip portion and an outer peripheral surface of the shaft member is set to be larger than the main lip in the main lip portion. a cross-sectional angle between the inclined surface of the sealing portion and the outer circumferential surface of the shaft member is large, and the auxiliary lip portion includes the inclined surface and the protruding surface on the inner circumferential surface, and the protruding surface is slidably coupled to the outer circumference of the shaft member At this time, the cross-sectional angle between the projection surface and the outer peripheral surface of the shaft member is equal to the seal side on the atmosphere side. A sealing member according to the first aspect of the patent application, wherein The fluid seal is joined to the sealing side of the inner circumference of the base. The sealing member according to the first aspect of the invention, wherein the outer tube is provided with an inner tube that is movably inserted into the outer tube in an axial direction, and a damper that is interposed between the outer tube and the inner tube. The aforementioned outer tube in the front fork fixes the base portion, and the inner tube is sealed as the shaft member with the inner tube as a shaft member.