JPH0443634Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a dust cover structure for a suspension damper, and particularly relates to an improvement in the structure for sucking and discharging air inside the dust cover to the outside.

(Prior Art) Conventionally, as an example of this type of dust cover structure, for example, as shown in Japanese Utility Model Application Publication No. 58-52347, the cylinder outer cylinder and the upper end are attached to the vehicle body through a mount member. A cylindrical dust cover is arranged around the piston rod of the suspension damper (shock absorber), which is attached to the suspension damper (shock absorber) and has a piston rod whose lower end is fitted into the cylinder outer cylinder so as to be vertically expandable and retractable. The upper end of the dust cover is airtightly fixed to the mount member and the lower end to the cylinder outer cylinder, and the air inside the dust cover is sucked in and out from the outside as the piston rod expands and contracts. It is known that a device is provided with an air intake/exhaust port to allow air to flow through the air.

(Problem to be solved by the invention) However, in the above-mentioned conventional device, the intake and exhaust ports provided at the bottom of the dust cover are simply openings.
It is unavoidable that dust and water will enter through the intake and exhaust ports. When dust enters through the intake and exhaust ports, the dust may adhere around the piston rod and impede its smooth sliding, or when the piston rod is at its maximum displacement (full bump), the dust may adhere to the upper end of the piston rod. There is a possibility that the bump stopper or the like may be damaged by being caught between the damper and the bump stopper above the bump stopper, which may lead to a decrease in the durability of the damper. Furthermore, if moisture or the like infiltrates, problems such as piston rods and the like may occur.

Therefore, the purpose of the present invention is to make appropriate improvements to the structure of the air intake and exhaust ports provided in the dust cover, thereby allowing air to flow into the dust cover without impairing the air intake and exhaust function within the dust cover. The purpose is to reliably prevent the intrusion of dust, water, etc., and to solve the above-mentioned problems all at once.

(Means for solving the problem) In order to achieve the above purpose, the solution of the present invention is as follows:
A cylinder outer cylinder, and a piston rod whose one end is attached to the vehicle body via a mount member and which extends and contracts in the axial direction with respect to the cylinder outer cylinder, are provided on the outside of the piston rod. The object of the present invention is a suspension damper in which a cylindrical dust cover is arranged with one end fixed to the mount member and the other end fixed to the cylinder outer tube in an airtight manner.

In this suspension damper, between the cylinder outer cylinder and the dust cover,
A dust intrusion prevention member is provided, which has a labyrinth-shaped communication path that communicates the air chamber in the dust cover with the outside. Further, in the communication passage, the annular passages stacked vertically in multiple stages along the outer circumferential surface of the cylinder outer cylinder, and the annular passages that are vertically adjacent to each other among the annular passages, are connected to the air in the dust cover. A ventilation hole is provided so that the communication path connecting the opening of the chamber and the opening on the outside of the dust cover is non-linear.

(Function) With the above configuration, according to the present invention, a dust intrusion prevention member is provided between the cylinder outer cylinder and the dust cover in the suspension damper, and the dust intrusion prevention member is provided with a dust intrusion prevention member that allows the dust to enter the dust cover as the piston rod expands and contracts. The outer peripheral surface of the cylinder outer cylinder is designed so that the communication path for sucking and discharging air from the air chamber to the outside is labyrinth-like, that is, the communication path connecting the opening of the air chamber inside the dust cover and the opening outside the dust cover is non-linear. Among the annular passages stacked vertically in multiple stages along the vertical direction, the annular passages that are vertically adjacent to each other communicate with each other through ventilation holes. The shaped communication path reliably prevents dust and the like from outside the dust cover from entering the internal air chamber. As a result, the smooth sliding of the piston rod is no longer hindered by the adhesion of dust, and when the piston rod is at its maximum displacement (at full bump), the dust is caught between the upper end of the piston rod and the bump stopper, causing the bump stopper, etc. They will not be damaged and their durability will be improved. In addition, as described above, the labyrinth-like communication path is arranged vertically along the outer peripheral surface of the cylinder outer cylinder so that the communication path connecting the opening of the air chamber inside the dust cover and the opening outside the dust cover is non-linear. Among the annular passages stacked in multiple stages in the direction, the annular passages that are vertically adjacent to each other communicate with each other through the ventilation holes.
This also prevents moisture from entering the air chamber and prevents piston rods from rusting.

Furthermore, since the labyrinth-like communicating path is formed in the dust intrusion prevention member as described above, the air chamber inside the dust cover can be closed by simply interposing the dust intrusion prevention member between the cylinder outer cylinder and the dust cover. A communication path (communication path) connecting the opening and the opening on the outside of the dust cover is formed, and there is no need to integrally provide a dust intrusion prevention member on the cylinder outer cylinder or the dust cover. In addition to being easy to process, the dust intrusion prevention member can be easily assembled.

Moreover, since the dust intrusion prevention member is interposed between the dust cover and the lower end of the cylinder outer cylinder as described above, there is no need to provide a separate water drain hole, and the communication path can also be used as a water drain hole. .

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 shows a strap type suspension according to an embodiment of the present invention, 1 is a damper of the suspension, 2 is a cylinder outer cylinder constituting the damper 1, and 3 is an axial direction with respect to the cylinder outer cylinder 2. It is a piston rod that is inserted so that it can expand and contract. The lower end of the cylinder outer cylinder 2 is connected to a wheel hub (not shown), while the upper end of the piston rod 3 is attached to the vehicle body 4 via a mount member 5.

Further, on the outside of the cylinder outer cylinder 2 and the piston rod 3, a substantially cylindrical dust cover 6 made of rubber or the like that can be expanded and contracted in the axial direction is provided, and its upper end is connected to the mount member 5 through a spring upper plate 7. The dust cover 6 is arranged with its lower end fixed to the upper part of the cylinder outer cylinder 2 in an airtight manner, and a sealed air chamber 8 is formed within the dust cover 6. Furthermore, around the upper part of the piston rod 3 in the air chamber 8, there is a bump stopper 9 which comes into contact with the upper end of the cylinder outer cylinder 2 and restricts its upward movement when the piston rod 3 is at its maximum displacement (at full bump). is provided. Further, a spring lower plate 10 is integrally attached to the cylinder outer cylinder 2, and a coil spring 11 is provided between the spring lower plate 10 and the spring upper plate 7.

As a feature of the present invention, a rubber dust intrusion prevention member 12 is interposed between the cylinder outer cylinder 2 and the dust cover 6. As shown in enlarged detail in FIGS. 2 and 3, the dust intrusion prevention member 12 has an outer circumferential surface fixed to the inner circumferential surface of the lower end of the dust cover 6, and a lower portion fixed to the outer wall of the cylinder outer cylinder 2 in an airtight manner. substantially funnel-shaped cover member 1
3, and a cylindrical seal member 16 that is integrally fixed to the inner peripheral surface 13a of the cover member 13.
The seal member 16 is attached to the inner circumferential surface 13 of the cover member 13.
a cylindrical base 14 fixed to a;
The cover members 13 each protrude inwardly and obliquely downward from the inner periphery, and the inner periphery abuts the outer circumferential surface of the cylinder outer cylinder 2.
Five tapered flange-shaped lip portions 15, 15, .
. . . and a plurality of annular passages 18, 18, . Further, among the lip portions 15, 15, . . . , each of the lip portions 15 that are vertically adjacent to each other has
A pair of semicircular ventilation holes 15 diametrically opposed to each other in the inner circumferential edge that abuts the outer circumferential surface of the cylinder outer tube 2.
a, 15a are formed by cutting out each lip portion 1.
The pair of ventilation holes 15a, 15a in 5 have a phase angle of 90° with respect to the upper and lower lip portions 15.
They are arranged alternately and staggered. The cover member 13 has a pair of passing ventilation holes 13.
b, 13b are provided corresponding to the ventilation holes 15a, 15a of the lowermost lip part 15, and these ventilation holes 13b, 13b and the ventilation holes 15a, 15a of each lip part 15, which are out of phase by 90 degrees, allow dust to be removed. A labyrinth-like connection is provided to communicate the vertically adjacent annular passages 18 so that the communication path (arrows shown in FIGS. 2 and 3) communicating between the outside of the cover 6 and the air chamber 8 inside is non-linear. A passage 17 is configured.

Therefore, in this embodiment, a dust intrusion prevention member 12 is interposed between the cylinder outer cylinder 2 and the dust cover 6 in the suspension damper 1, and the dust intrusion prevention member 12 is provided with:
The communication passage 17 that communicates the outside of the dust cover 6 with the air chamber 8 inside is shaped like a labyrinth, that is, the passages 17 in each lip part 15 are alternately arranged with a phase shift of 90 degrees with respect to the upper and lower lip parts 15. A pair of ventilation holes 15a, 15a and a pair of ventilation holes 13b, 13b of the cover member 13 provided corresponding to the ventilation holes 15a, 15a of the lowermost lip part 15 create air chambers inside and outside the dust cover 6. Since the vertically adjacent annular passages 18 are configured to communicate with each other so that the communication passages communicating with the suspension damper 1 are non-linear, dust flows through the communication passages 17 as the suspension damper 1 expands and contracts. Air flowing in and out of the air chamber 8 in the cover 6 flows through the air holes 15a, 15a of each lip part 15 with a phase change of 90 degrees. In this way, air passes through the communication path 17
By flowing in a complicated flow path while changing direction, it is ensured that dust contained in the air enters the air chamber 8 in the dust cover 6 through the communication path 17 without impairing its intake and exhaust function. can be prevented. Therefore, dust may adhere around the piston rod 3 and prevent its smooth sliding, or dust may become trapped between the upper end of the piston rod 3 and the bump stopper 9 when the piston rod 3 is at its maximum displacement (at full bump). It is possible to reliably prevent the bump stopper 9 and the like from being damaged by the bump stopper 9, and the durability of these members can be improved.

Furthermore, it is possible to similarly prevent moisture and the like from entering the air chamber 8 within the dust cover 6. Even if moisture etc. infiltrates, the moisture will be absorbed by the tapered lip portions 15, 15, . . .
...flows downward and the ventilation hole 1 of the cover member 13
The water is drained to the outside through 3b and 13b, thereby effectively preventing the piston rod 3 and the like from rusting.

Furthermore, since the labyrinthine communication path 17 is formed in the dust intrusion prevention member 12 as described above,
By simply interposing the dust intrusion prevention member 12 between the cylinder outer cylinder 2 and the dust cover 6, a communication path (communication path 17) that communicates the outside of the dust cover 6 with the air chamber 8 inside is configured. Therefore, it is not necessary to provide the dust intrusion prevention member integrally with the cylinder outer cylinder or the dust cover, and the processability thereof is improved, and the ease of assembling the dust intrusion prevention member 12 can be improved.

In addition, as described above, the dust intrusion prevention member 12 is located at the lower end of the cylinder outer cylinder 2 so that the dust cover 6
Since it is interposed between the drain hole and the drain hole, there is no need to provide a separate drain hole, and the communication path 17 can also be used as a drain hole.

(Effects of the invention) As described above, in the present invention, a dust intrusion prevention member is interposed between the cylinder outer cylinder and the dust cover in the suspension damper, and the dust intrusion prevention member is attached to the air chamber inside the dust cover. The communication passages for sucking and discharging air from the outside are arranged so that the communication passages are non-linear, and the annular passages are vertically adjacent to each other among the annular passages stacked vertically in multiple stages along the outer peripheral surface of the cylinder outer cylinder. The dust cover communicates through the ventilation holes and is formed in a labyrinth shape, so it is possible to reliably prevent foreign matter such as dust and moisture from outside the dust cover from entering the internal air chamber without impairing its intake and exhaust function. This makes it possible to reliably prevent an increase in the sliding resistance of the piston rod due to dust adhesion, damage to the dump stopper etc. due to dust when the piston rod is at its maximum displacement, and rusting of the piston rod etc. due to the ingress of moisture. In this way, the durability of the suspension damper as a whole can be improved. Moreover, by forming the labyrinth-like communication path in the dust intrusion prevention member, there is no need to provide the dust intrusion prevention member integrally with the cylinder outer cylinder or the dust cover, improving workability and ease of assembly. In addition, the communication passage can also be used as a drain hole by means of a dust intrusion prevention member interposed between the dust cover and the lower end of the cylinder outer cylinder.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the overall structure of the suspension damper, FIG. 2 is an enlarged sectional view of a main part, and FIG. 3 is a sectional view taken along the line -- in FIG. 1... Damper, 2... Cylinder outer cylinder, 3...
Piston rod, 4...Car body, 5...Mount member, 6...Dust cover, 8...Air chamber, 12...
...Dust intrusion prevention member, 17...Communication path, 18...
...Circular passage.

Claims (1)

[Scope of utility model registration request] It is equipped with a cylinder outer cylinder and a piston rod whose one end is attached to the vehicle body via a mount member and which extends and contracts in the axial direction with respect to the cylinder outer cylinder, and the outside of the cylinder outer cylinder and piston rod can be expanded and contracted in the axial direction. In the suspension damper, a substantially cylindrical dust cover is arranged with one end fixed to the mounting member and the other end fixed to the cylinder outer cylinder in an airtight manner, between the cylinder outer cylinder and the dust cover. is equipped with a dust intrusion prevention member that is formed with a labyrinth-like communication path that communicates the air chamber inside the dust cover with the outside, and the communication path extends vertically along the outer circumferential surface of the cylinder outer cylinder. There is no communication path that connects the annular passages stacked in multiple stages and the annular passages that are vertically adjacent to each other among the annular passages between the opening of the air chamber in the dust cover and the opening outside the dust cover. A dust cover structure for a suspension damper, characterized by having a ventilation hole communicating in a straight line.