JP3943176B2 - Inverted strut damper - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inverted strut damper.
[0002]
[Prior art]
As the inverted strut damper, (1) Japanese Patent Laid-Open No. 6-330975 “Strut suspension” and (2) Japanese Patent Laid-Open No. 5-223138 “hydraulic damper device” are known.
[0003]
The above {circle around (1)} is a technique relating to a strut suspension that secures rigidity against the bending moment of the shock absorber and has a reduced overall length. As shown in FIG. The lower closed end 22a, the piston rod 26 extending upward from the closed end 22a, the piston 25 supported by the upper end of the piston rod 26, and the outer surface of the piston 25 and the inner surface of the outer cylinder 22 are slidable. An inner cylinder 27 inserted into the inner cylinder 27, a rod guide 28 attached above the opening end 27b at the lower part of the inner cylinder 27, a closed end 27a at the upper part of the inner cylinder 27, and a bound stopper 24 attached to the lower outer surface of the piston rod 26. Is provided.
[0004]
The above (2) is a technique aimed at improving assembly, stability and durability and reducing the size in the radial direction. As shown in FIG. The intermediate cylinder 3 provided on the inner side of the outer cylinder 2, the base member 11 attached to the lower part of the outer cylinder 3, the base member 12 provided on the upper part of the base member 11, and the base member 12 extending upward. A piston rod 7, a piston 6 supported by the upper end of the piston rod 7, an inner cylinder 5 slidably inserted between the outer surface of the piston 6 and the inner surface of the intermediate cylinder 3, and a lower end of the inner cylinder 5 A lower bearing 10 attached to the upper end of the intermediate cylinder 3, and a stopper member 24 attached to the lower outer surface of the piston rod 7.
[0005]
[Problems to be solved by the invention]
In the above (1), since the closed end 22a of the outer cylinder 22 is provided above the lower end of the outer cylinder 22, the position of the open end 27b of the inner cylinder 27 can be maintained even when the suspension is most compressed. It does not fall below the position of the end 22a. Here, when the position of the closed end 27a at the upper part of the inner cylinder 27 is not changed, the entire length of the inner cylinder 27 is shortened, and there is a disadvantage that a large stroke cannot be obtained.
[0006]
Further, in the above (2), since the position of the base member 12 attached to the lower part of the outer cylinder 2 is above the lower end of the outer cylinder 2, the position of the lower end of the inner cylinder 5 has compressed this damper device most. Even in this case, the position does not fall below the position of the base member 12. Therefore, like the above (1), there arises a disadvantage that the stroke cannot be made large.
Accordingly, an object of the present invention is to provide an inverted strut damper capable of increasing the stroke by lowering the position of the inner cylinder with respect to the outer cylinder.
[0007]
[Means for Solving the Problems]
Claim 1 of the present invention in order to achieve the above object, in the center of the lower lid, by forming a collision inverse cup-shaped portion on than the inner diameter of the lower end of the inner cylinder having an outer diameter smaller, most compression with inverted cup-shaped portion at the bottom of the inner cylinder is adapted to enter at, it was so that to house the lower end and the nut of the rod lower space of the inverse cup-shaped portion.
Since the reverse cup-shaped portion enters the inner cylinder at the time of maximum compression, the position of the inner cylinder can be further lowered and the stroke can be increased. Moreover, the lower end part and nut of a rod can be accommodated in a lower cover, and the lower end part and nut of a rod do not protrude from the lower part of an outer cylinder, and do not interfere with others.
[0008]
According to a second aspect of the present invention, a seal member for containing oil is attached to the lower part of the inner cylinder, and pressurized gas is filled below the seal member and in the lower part of the outer cylinder.
The lower part of the outer cylinder can be a spring made of pressurized gas, and the spring characteristics of the inverted strut damper can be freely set by changing the gas pressure of this spring.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a cross-sectional view of an inverted strut damper according to the present invention at the time of extension. The inverted strut damper 1 has an outer cylinder 3 (generally referred to as a strut tube) provided with a mounting bracket 2 as a damper as an inner cylinder. The tube 4 is inserted so as to be movable up and down, and the damper piston 5 faces the inside of the damper tube 4. The damper piston 5 is fixed to the lower cover 7 of the outer cylinder 3 through the rod 6, and the upper portion of the damper tube 4 is A bumping rubber 8 and a dustproof boot 9 are attached downward, and a suspension spring 13 is attached between an upper spring seat 11 attached to the upper end of the damper tube 4 and a lower spring seat 12 attached to the outer surface of the outer cylinder 3. It is a damper.
15 is a rod guide, 16 is an oil seal as a seal member, 17 is an oil seal stopper, and 18 is a mounting bracket.
[0010]
The basic operation of the inverted strut damper 1 will be described.
In FIG. 1, the first chamber 21 above the damper piston 5 accumulates gas 23 in the upper portion and hydraulic oil 24 in the lower portion. The oil is the same, but the sign has been changed to distinguish the position.)
When a pressing force is applied to the damper tube 4 relatively, a part of the hydraulic oil 24 in the first chamber 21 starts to move to the second chamber 22 via the orifice of the damper piston 5 and a damping force is generated.
[0011]
FIG. 2 is a sectional view of the inverted strut damper according to the present invention at the time of contraction, showing that the height position of the damper piston 5 does not change and the damper tube 4 is fully lowered. At this time, the increase in the volume of the rod 6 entering the second chamber 22 is absorbed by the gas 23 in the upper portion of the first chamber 21 being compressed and contracted.
[0012]
FIG. 3 is an enlarged cross-sectional view of the upper portion of the outer cylinder according to the present invention. The upper diameter of the outer cylinder 3 is enlarged to form a large diameter portion 31, and the upper inner surface of the outer cylinder 3 above the large diameter portion 31 is formed. An upper oil seal 32 and an upper bearing 33 are attached below the upper oil seal 32, a lower bearing 34 is attached to the inner surface of the outer cylinder 3 below the large-diameter portion 31, and a lower oil seal 35 is attached below the upper bearing. The damper tube 4 is inserted into the upper and lower bearings 33 and 34 so as to be movable up and down, and the space surrounded by the upper and lower oil seals 32 and 35, the outer cylinder 3 and the damper tube 4 is upper and lower oil seals 32 and 35. And it shows that it was set as the lubricating oil chamber 36 for lubricating the upper and lower bearings 33 and 34.
[0013]
3 shows that the outer cylinder 3 is reduced in diameter or locally recessed so that a stopper collar 37 is fixed to the inner surface of the outer cylinder 3, and a lower oil seal 35 is applied to the upper portion of the stopper collar 37. A lower bearing 34 is attached to the oil seal 35, an upper bearing 33 is attached to the upper oil seal 32, a distance collar 38 is interposed between the upper and lower bearings 33, 34, and the upper bearing 34 is provided in the lubricating oil chamber 36. It shows that the attached lubricating oil impregnated member 41, the O-ring 42 fitted to the outer surface of the damper tube 4, and the hollow elastic body 43 provided in the lower part are accommodated.
[0014]
In the outer cylinder 3, when the inner diameter of the position where the upper oil seal 32 and the upper bearing 33 are attached is D1, the inner diameter of the large diameter portion 31 is D2, and the inner diameter of the position where the lower bearing 34 and the lower oil seal 35 are attached is D3, D2> D1 = D3.
The upper bearing 33 is a housing 33a fitted with a bearing body 33b. The lower bearing 34 is also formed by fitting a bearing body 34b to a housing 34a.
The outer diameters of the upper bearing 33 and the lower bearing 34, and the upper oil seal 32 and the lower oil seal 35 are the same and can be shared.
[0015]
The lubricating oil chamber 36 is a sealed space and, as a general rule, is fully filled with lubricating oil during assembly. The volume of the lubricating oil changes with temperature. When the lubricating oil expands, the hollow elastic body 43 contracts and absorbs it, and when the lubricating oil contracts, the hollow elastic body 43 expands. Therefore, the lubricating oil can be apparently fully filled. As a result, the upper oil seal 32 and the upper bearing 33 can be immersed in the lubricating oil, and good lubrication is possible.
The stopper collar 37 is a member that suppresses the lowering of the lower bearing 34, and is a thin plate cylinder in this example.
[0016]
The distance collar 38 is a member that suppresses the lowering of the upper bearing 33 and the lowering of the lower bearing 34. In this example, the distance collar 38 is a thin two-stage cylinder with a small diameter at the lower part, and an annular shape that suppresses the lowering of the lubricating oil impregnated member 41 at the upper part. It is a member which has the inward convex part 38a.
The lubricating oil impregnated member 41 is a member that impregnates oil and supplies the oil to the upper bearing 33 and the upper oil seal 32 to promote lubrication of the upper bearing 33 and the upper oil seal 32. For example, the lubricating oil impregnated member 41 is formed in a ring shape. A felt (generally called a felt ring) is suitable.
[0017]
The O-ring 42 moves integrally with the damper tube 4 when moving in the oil in the lubricating oil chamber 36, and is movable relative to the damper tube 4 when a mechanical external force acts. It is.
Thereby, when the damper tube 4 moves up, the O-ring 42 can pump up the oil and supply the oil to the upper bearing 33 and the upper oil seal 32. Further, the figure shows a state in which the O-ring 42 hits the inwardly protruding portion 38a of the distance collar 38 after the damper tube 4 has moved upward, and the O-ring 42 is bent by the distance collar 38 after the damper tube 4 has moved downward. As shown by the imaginary line, the upper portion of the portion 38b is hit.
[0018]
The moving amount L of the O-ring 42 is smaller than the stroke amount of the inverted strut damper 1. That is, when the damper tube 4 is moved upward, the O-ring 42 first moves integrally with the damper tube 4, but slides on the outer surface of the damper tube 4 when it hits the inward convex portion 38 a of the distance collar 38. Further, when the damper tube 4 is moved downward, the O-ring 42 initially moves integrally with the damper tube 4, but slides on the outer surface of the damper tube 4 when hitting the bent portion 38 b of the distance collar 38.
Thereby, the stroke of the inverted strut damper 1 can be increased, or the overall length of the outer cylinder 3 can be decreased.
[0019]
The hollow elastic body 43 is an elastic body including one or a plurality of cavities 43a (not shown), which do not communicate with the outside, and the like, for example, an independent foamed elastic body or urethane rubber. Or a foamed resin wrapped with a thin rubber or resin is preferred.
[0020]
FIG. 4 is an enlarged cross-sectional view of the lower portion of the outer cylinder according to the present invention during contraction, and an inverted cup-shaped portion 7a is formed by projecting the center portion of the lower lid 7 of the outer cylinder 3 upward, The lower lid 7 is an inverted cup-shaped member, the rod 6 is attached to the bottom 7b of the inverted cup-shaped portion 7a with a nut 51, and the outer diameter of the inverted cup-shaped portion 7a of the lower lid 7 is the inner diameter of the lower end of the damper tube 4 The rod guide 15, the oil seal 16, and the oil seal stopper 17 are attached to the lower portion of the damper tube 4 so as to be offset upward so that the reverse cup-shaped portion 7 a can enter the lower portion of the damper tube 4. Indicates that
Thereby, the position of the lower end of the damper tube 4 can be lowered, and the stroke of the inverted strut damper 1 can be increased.
[0021]
Even if the lower lid 7 is an inverted cup-shaped member, the lower end position of the damper tube 4 does not rise, so that the position of the lower bearing 34 relative to the outer cylinder 3 determined at the time of maximum extension does not rise as shown in FIG. The bearing distance between the lower bearing 34 and the upper bearing 33 (see FIG. 3) is not shortened. Accordingly, the rigidity can be maintained against the bending force acting on the inverted strut damper 1.
Furthermore, the lower end of the rod 6 does not protrude from the lower part of the outer cylinder 3 and does not interfere with, for example, a dustproof boot of the drive shaft disposed at the lower part of the inverted type slorrat damper 1.
[0022]
FIG. 4 also shows a valve 53 for supplying gas to a gas chamber 52 which is a space surrounded by the outer cylinder 3, the damper tube 4, the lower oil seal 35 and the lower lid 7, above the mounting bracket 2 of the outer cylinder 3. Indicates installation. In this case, the oil seals 16 and 35 have high pressure resistance.
In this way, by supplying gas from the valve 53 to the gas chamber 52 and setting the gas chamber 52 to a predetermined pressure, the spring characteristics of the inverted strut damper 1 can be made to be a spring by the pressurized gas in the gas chamber 52 and a suspension spring. 13 (see FIG. 3) can be set freely.
[0023]
Further, the damper tube 4 can be moved up and down by supplying gas to the gas chamber 52 through a valve 53 from the outside or discharging the gas from the gas chamber 52 with a compressor (not shown). The damper tube 4 is mounted on the mounting bracket. The vehicle height of a vehicle body (not shown) to be attached via 18 (see FIG. 1) can be adjusted.
[0024]
【The invention's effect】
The present invention exhibits the following effects by the above configuration.
Inverted strut damper according to claim 1, in the center of the lower lid, by forming a collision inverse cup-shaped portion on than the inner diameter of the lower end of the inner cylinder having a smaller outer diameter, the lower portion of the inner cylinder at top compression in conjunction with the inverse cup-shaped portion is adapted to enter, since the so that to house the lower end and the nut of the rod lower space of the inverse cup-shaped portion, the inverted cup-shaped part the inner cylinder during most compression The position of the inner cylinder can be lowered by entering, and the stroke can be increased . Also, it is possible to house the lower end and the nut of the rod in the lower lid, the lower end portion and the nut of the rod does not protrude from the bottom of the outer tube does not interfere to the other.
[0025]
The inverted strut damper according to claim 2 is provided with a seal member for containing oil in a lower part of the inner cylinder, and a pressurized gas is filled below the seal member and in the lower part of the outer cylinder. The spring characteristic of the inverted strut damper can be freely set by changing the gas pressure of the spring.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an inverted strut damper according to the present invention when extended. FIG. 2 is a cross-sectional view of an inverted strut damper according to the present invention when contracted. FIG. 3 is an enlarged cross-sectional view of an upper portion of an outer cylinder according to the present invention. FIG. 4 is an enlarged cross-sectional view of the lower part of the outer cylinder according to the present invention when contracted.
DESCRIPTION OF SYMBOLS 1 ... Inverted strut damper, 3 ... Outer cylinder, 4 ... Inner cylinder (damper tube), 5 ... Damper piston, 6 ... Rod, 7 ... Lower lid, 7a ... Reverse cup shape part, 16 ... Seal member (oil seal) 32 ... Upper oil seal, 33 ... Upper bearing, 34 ... Lower bearing, 35 ... Lower oil seal, 51 ... Nut, 52 ... Gas chamber.

Claims (2)

An inner cylinder is attached to an upright outer cylinder through an upper oil seal, upper bearing, lower bearing, and lower oil seal so that it can move in the axial direction. A damper piston is accommodated in the inner cylinder, and this damper piston is inserted via a rod. In the inverted strut damper attached to the lower lid of the outer cylinder ,
At the center of the front Symbol lower cover, than the inner diameter of the lower end of the inner tube by forming a collision inverse cup-shaped portion onto which has a smaller outer diameter, said inverted cup-shaped portion at the bottom of the inner cylinder at top compression while adapted to enter, inverted strut damper, characterized in that the so that to house the lower end and a nut of the rod lower space of the inverse cup-shaped portion. Mounting a seal member for keeping containment oil at the bottom of the front Symbol inner tube, inverted according to claim 1, wherein the filled with pressurized gas at the bottom of and within the outer tube at the lower side of the sealing member Strut damper.

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