JPH09210212A - Seal structure of liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain the intrusion of solid foreign materials into a contacting portion between a seal member and a movable member. SOLUTION: This seal structure puts a slidable portion of a seal member 11 into contact with a movable member 15 which is movable relative to holding members 13 and 14 for holding the seal member 11 made of elastic material such as rubber or resin, so as to seal liquid contained on one side of the seal member 11. In this case, A weir 18 detached from the movable member 15 is provided in the seal member 11 and is positioned on the liquid storage part side of a contacting portion of the seal member 11 with the movable member 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid sealing structure provided between two members for preventing liquid leakage.

[0002]

2. Description of the Related Art As one of liquid sealing structures, a part of a sealing member made of an elastic material such as rubber or resin and held by a holding member can be slid on a movable member movable with respect to the holding member. There is one that is brought into contact with the seal member to seal the liquid contained in one side of the seal member.
For example, it is disclosed in Japanese Utility Model Publication No. 3-1361.

In the liquid seal structure disclosed in the above publication, a magnet is embedded adjacent to a portion (sliding part) of the seal member that abuts on the movable member, so that iron powder in the liquid is magnetized. The metal powder is attracted to the magnet.
Therefore, in this liquid seal structure, abrasion of the portion of the seal member that comes into contact with the movable member due to the magnetic metal powder such as iron powder is suppressed, and the sealing performance is ensured for a long period of time.

[0004]

In the liquid seal structure disclosed in the above publication, only magnetic powder of magnetic metal such as iron powder is attracted to the magnet, and non-magnetic metal powder such as aluminum powder. Is not adsorbed by the magnet, and no effective effect can be obtained with respect to non-magnetic metal powder such as aluminum powder or non-metallic solid foreign matter.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a part of a seal member made of an elastic material such as rubber or resin and held by a holding member is held by the holding member. In a liquid seal structure that slidably contacts a movable member that is movable with respect to a member to seal the liquid contained in one side of the seal member, a portion of the seal member that contacts the movable member. It is characterized in that a weir that is not in contact with the movable member is provided on the seal member closer to the liquid storage portion. It is desirable that the weir is formed of a member different from the seal member. Further, it is desirable that the weir is provided with a liquid pressure difference suppressing means for suppressing a pressure difference of the liquid before and after the weir.

[0006]

In the liquid seal structure according to the present invention, the weir provided in the seal member allows the solid foreign matter (such as iron powder) to adhere to the contact portion between the seal member and the movable member in the liquid. Not only magnetic metal powder but also non-magnetizable metal powder such as aluminum powder and various non-metal substances are prevented from entering), so solid foreign matter in the liquid abuts the seal member and movable member. It is suppressed that the part is bitten into the part, abrasion of the contact part due to solid foreign matter is suppressed, and the deterioration of the sealing property is significantly suppressed. Moreover, since the weir provided in the seal member is not in contact with the movable member, it does not hinder the sliding of the movable member.

When the weir is formed of a member different from the seal member, a rigid material is used as the weir material.
The function as a weir can be sufficiently exerted, and the weir can be configured by a magnet material to reliably capture magnetic metal powder such as iron powder.

Further, in the case where the weir is provided with the liquid pressure difference suppressing means for suppressing the pressure difference of the liquid before and after the weir, the liquid before and after the weir is prevented from interfering with the function of suppressing the intrusion of solid foreign matter by the weir. The pressure difference can be suppressed, the deformation of the seal member due to the same pressure difference can be suppressed, and the sealing function of the seal member can be properly exerted.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of a liquid sealing structure according to the present invention. This sealing structure is adopted at both left and right ends B and C of a power cylinder A of a vehicle power steering apparatus as shown in FIG. 3, for example. In this seal structure, an annular seal member 11 made of an elastic material such as rubber or resin is used as a holding member by using an annular reinforcing member 12 having an L-shaped cross section and an aluminum cylinder 13 and a sleeve ( (Assembled in the cylinder 13) 14 is held. In addition, the seal member 11
Has a middle portion of its lip 11a slidably brought into contact with a piston rod (rack bar) 15 as a movable member, whereby the liquid contained in the right side of FIG. 1 of the seal member 11 is sealed. There is.

Further, in the seal structure shown in FIG. 1, a backup ring 16 is provided for the purpose of preventing the lip 11a of the seal member 11 from reversing and reinforcing it, and presses (tightens) the lip 11a against the piston rod 15. The garter spring 17 is provided. It is also possible to form the backup ring 16 from a magnet material so as to adsorb and capture the magnetic metal powder such as iron powder that is going to enter from the outside.

By the way, in the seal structure of the present embodiment, the tip of the lip 11a of the seal member 11, that is, the portion of the lip 11a that abuts the piston rod 15 on the liquid storage portion side (right side in FIG. 1), with respect to the piston rod 15. And a non-contact weir 18 is provided, and the lip 11a
1, a weir 19 that is not in contact with the piston rod 15 is provided on the left side of FIG. Each weir 18, 19
Is formed of a magnet material in an annular shape, and is fitted and fixed to the recesses 11b and 11c provided in the seal member 11 at the outer peripheral portion thereof.
A radial gap δ is formed between the outer peripheries of 5. The gap δ is 0.02 mm to 0.05 mm.

In the seal structure of the present embodiment constructed as described above, the weir 18 provided in the seal member 11 causes the solid foreign matter (in this case, solid foreign matter) in the liquid to come into contact with the seal member 11 and the piston rod 15. , Non-magnetizable metal powder such as aluminum powder and various non-metal substances are also prevented from entering. Therefore, solid foreign matter in the liquid is sealed by the seal member 11. This prevents the piston rod 15 from being bitten into the abutting portion. Further, in the seal structure of the present embodiment, the weir 19 provided in the seal member 11 suppresses the entry of solid foreign matter into the contact portion between the seal member 11 and the piston rod 15 from the outside. It is possible to prevent the solid foreign matter from being caught in the contact portion between the seal member 11 and the piston rod 15.

Therefore, in the seal structure of the present embodiment, abrasion of the contact portion between the seal member 11 and the piston rod 15 with solid foreign matter is greatly suppressed, and deterioration of the sealing property is significantly suppressed. In addition, the dams 18 and 19 provided on the seal member 11 are the piston rod 1
Since it is not in contact with 5, the sliding of the piston rod 15 is not hindered. In the present embodiment,
Since each of the weirs 18 and 19 is made of a magnetic material, the magnetic metal powder having magnetism such as iron powder is adsorbed by each of the weirs 18 and 19 to be reliably captured.

FIG. 2 shows another embodiment of the liquid sealing structure according to the present invention. In the sealing structure of this embodiment, a mounting portion 18a having a substantially circular cross section is provided at the outer peripheral end of the weir 18.
Is formed, a communication hole 18b is formed in the middle portion, and a tapered surface 18c is formed in the inner peripheral portion. The mounting portion 18a is
This is for ensuring a predetermined mounting strength with respect to the seal member 11, and is fitted and fixed to a recess 11d provided in the seal member 11. The communication holes 18b are for allowing the passage of the liquid and for restricting the passage of the solid foreign matter in the liquid. The communication holes 18b are provided at a plurality of substantially equal intervals in the circumferential direction, and the diameter thereof is 0.02 of the size of the gap δ. It should be less than mm ~ 0.05 mm. Other configurations are the same as those of the seal structure shown in FIG.

In the seal structure of FIG. 2 configured as described above, the pressure difference of the liquid before and after the weir 18 can be suppressed without impeding the function of the weir 18 to prevent the entry of solid foreign matter. The deformation of the seal member 11 (the deformation of the tip of the lip 11a) due to the pressure difference can be suppressed, and the sealing function of the seal member 11 can be properly exerted.

In each of the above-mentioned embodiments, each weir 1
Although 8 and 19 are fitted and fixed in the recesses of the seal member 11, insert molding at the time of molding the seal member 11 facilitates dimensional control of the gap δ. In addition, in each of the above-described embodiments, the weir 19 is provided at the base of the lip 11a of the seal member 11, but the weir 19 may be omitted to implement the present invention. In addition, in each of the above-described embodiments, each weir 1
Although 8 and 19 are made of a magnetic material, the weirs 18 and 19 may be made of a material different from the magnetic material, and they should be integrally formed of the same material as the seal member 11. Is also possible. In the embodiment shown in FIG. 2, weir 18
Although the communication hole 18b is provided in the above, it is also possible to implement the weir itself by a member having liquid permeability, and in this case also, it is possible to suppress the pressure difference of the liquid before and after the weir. You can

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a liquid sealing structure according to the present invention.

FIG. 2 is a cross-sectional view of an essential part showing another embodiment of the liquid sealing structure according to the present invention.

FIG. 3 is a partial cutaway view of the power steering apparatus for an automobile showing one place of use of the liquid seal structure shown in FIGS. 1 and 2.

[Explanation of symbols]

11 ... Seal member, 11a ... Lip, 11b, 11c,
11d ... Recess, 12 ... Reinforcing member, 13 ... Cylinder, 14
... sleeve, 15 ... piston rod, 16 ... backup ring, 17 ... garter spring, 18, 19 ... weir,
18a ... Communication hole.

Claims (3)

[Claims] 1. A seal member made of an elastic material such as rubber or resin and held by a holding member so that a part of the seal member slidably abuts a movable member movable with respect to the holding member. In a liquid sealing structure for sealing a liquid contained in one side, a weir that is not in contact with the movable member is provided on the side of the liquid containing portion with respect to the movable member of the seal member in the seal member. A liquid seal structure characterized by being provided. 2. The liquid seal structure according to claim 1, wherein the weir is formed of a member different from the seal member. 3. The liquid seal structure according to claim 1, wherein the weir is provided with a liquid pressure difference suppressing means for suppressing a liquid pressure difference before and after the weir.