JP2002061698A - Structure of part for adjusting spring force - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make total unit weight reducible and a total unit diameter diametrically contractible in a hydraulic shock absorber while spring tension can be adjusted to change in a suspension spring interposed in the hydraulic shock absorber. SOLUTION: In this structure of a part for adjusting spring tension, set by supplying pressure oil from in a cylinder 1 relating to an annular pressure chamber R formed between an annular housing 41 fixedly mounted in the external periphery of the cylinder 1 and an annular piston 42 received to be mounted in an internal peripheral side of this annular housing 41 to protrude the annular piston 42 from in the annular housing 41 additionally so as to return oil in the pressure chamber R into the cylinder 1 through a drain hole 1c drilled to open in the cylinder 1 when a protruded amount of the annular piston 42 from in the annular housing 11 is increased to a preset value or more, a seal member 7 coming into slide contact with an external periphery of the cylinder 1 is arranged in an internal peripheral side of an end part serving as a spring receiving side in the annular piston 42, and a bearing member 8 coming into slide contact with an external periphery of the cylinder 1 is arranged in an internal peripheral side of an end part serving as a side of the pressure chamber R in the annular piston 42, in addition a backup member 9 is adjacently provided behind this bearing member 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spring force adjusting structure, and more particularly to a suspension spring which is interposed on the outer periphery of a self-pumping type hydraulic shock absorber and urges the hydraulic shock absorber in an extending direction. The present invention relates to an improvement in a spring force adjusting portion structure that enables a height adjustment of a spring force.

[0002]

2. Description of the Related Art Conventionally, there are various spring force adjusting structures which are interposed on the outer periphery of a hydraulic shock absorber and enable the spring force of a suspension spring which urges the hydraulic shock absorber in the extending direction to be adjusted. There is a proposal.

[0003] Among them, the spring force adjusting portion structure shown in FIG. 2 uses a cylinder 1 as an upper member and a piston rod 2 protruding and retracting with respect to the cylinder 1 as a lower member while being of a self-pumping type. In the hydraulic shock absorber set as an inverted type, the upper end of a suspension spring 3 that urges the piston rod 2 to protrude from the cylinder 1 is moved up and down by the operation of the jack portion 4, whereby the suspension spring 3
The height of the spring force can be adjusted.

That is, in the conventional example shown in FIG. 2, the jack portion 4 constitutes a spring force adjusting portion structure. As shown, the jack portion 4 is the upper end side of the hydraulic shock absorber. Bottom part 1 of cylinder 1
The annular housing 41 is fixed to the outer circumference of the cylinder 1 and is slidably mounted on the inner circumference of the annular housing 41 while being interposed on the outer circumference of the cylinder 1. And an annular piston 42 for locking the upper end of the suspension spring 3.
An annular pressure chamber R is formed between the piston and the annular piston 42.

The pressure oil from the pump chamber P is introduced into the pressure chamber R due to the repetition of expansion and contraction in the hydraulic shock absorber, that is, the pumping operation in which the piston rod 2 repeatedly moves in and out of the cylinder 1. 5 and the bottom portion 1a of the cylinder 1 is supplied through an opening channel 1b.

Therefore, when pressurized oil is supplied to the pressure chamber R in the jack part 4 by the pumping operation due to the expansion and contraction of the hydraulic shock absorber, the annular piston 42 comes out of the annular housing 41, and therefore the suspension spring 3 Is pushed down, and the spring force of the suspension spring 3 is adjusted to be high.

[0007] When the hydraulic shock absorber enters the predetermined extended state, the supply of the pressure oil to the pressure chamber R by the pumping operation is stopped, and the spring force of the suspension spring 3 is maintained in the adjusted state. .

Further, when a high load acts on the suspension spring 3 and the hydraulic shock absorber is further compressed, the spring force of the suspension spring 3 is further adjusted to return the hydraulic shock absorber to a predetermined extended state. At this time, the annular piston 42 slides and largely projects from the inside of the annular housing 41.

That is, in this spring force adjusting portion structure, when the load acting on the suspension spring 3 becomes excessive, the oil in the pressure chamber R is drained into the cylinder 1 by the projection of the annular piston 42 when the annular piston 42 projects. The so-called relief operation for returning the cylinder piston 1 to the inside of the cylinder 1 through the hole 1c,
2 is prevented from falling out of the annular housing 41, that is, being prevented from falling off.

[0010]

However, it may be pointed out that the above-described conventional spring force adjusting structure has a problem that the entire diameter of the hydraulic shock absorber is easily increased.

That is, in the above-mentioned spring force adjusting portion structure,
In the structure for preventing the annular piston 42 from coming out of the annular housing 41 by the above-described relief operation,
As shown in FIG. 3, a drain hole 1 opened in the cylinder 1
It is indispensable to arrange the sealing members 6 and 7 as oil seals around c to ensure liquid tightness.

At this time, as shown by an imaginary line in FIG. 3, if one of the seal members 6 is disposed on the inner peripheral side of the end of the annular piston 42 on the pressure chamber R side, the relief operation is performed. Therefore, when the annular piston 42 slides, the seal member 6 rubs the opening end of the drain hole 1c so to speak, so that the seal member 6 is damaged and the sealing performance is reduced. This leads to a problem of lowering.

Therefore, as shown by a solid line in FIG. 3, by arranging the above-mentioned sealing member 6 together with the other sealing member 7 on the outer peripheral side of the cylinder 1, it is possible to avoid a decrease in sealing performance. On the other hand, since the seal member 6 (and the seal member 7) is arranged on the outer periphery of the cylinder 1, it is necessary to increase the thickness of the cylinder 1 and, as a result, increase the weight of the hydraulic shock absorber and increase the overall diameter. Is increased, for example, so that the tower mountability on the vehicle is easily reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to make it possible to adjust a spring force of a suspension spring provided in a hydraulic shock absorber. Of course, it is possible to reduce the weight of the hydraulic shock absorber and reduce the overall diameter, for example,
An object of the present invention is to provide a spring force adjusting portion structure which is optimal for improving the versatility of a hydraulic shock absorber by improving tower mountability on a vehicle.

[0015]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention is basically applied to an outer periphery of a cylinder constituting a self-pumping type hydraulic shock absorber having a suspension spring interposed on the outer periphery. And a spring receiver which is slidably housed between the inner periphery of the annular housing and the outer periphery of the cylinder to partition the annular pressure chamber and abut on one end of the suspension spring. When the amount of protrusion of the annular piston from the inside of the annular housing becomes greater than or equal to the set value, the annular piston projects from the inside of the annular housing by supplying pressure oil from inside the cylinder to the pressure chamber. In the spring force adjusting portion structure which is set so that oil in the pressure chamber is returned into the cylinder through a drain hole formed in the cylinder, an inner periphery of an end of the annular piston which is a spring receiving side. A seal member that slides on the outer periphery of the cylinder, and a bearing member that slides on the outer periphery of the cylinder is disposed on the inner peripheral side of the end portion of the annular piston that is on the pressure chamber side; And a backup member is provided adjacent to the back of the device.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the illustrated embodiment. However, even in the spring force adjusting portion structure according to the present invention, the same as the above-described conventional spring force adjusting portion structure. It is assumed to be embodied as a self-pumping type inverted hydraulic shock absorber having a suspension spring 3 interposed on the outer periphery, and is basically the same as the above-described conventional spring force adjusting portion structure. It is configured to be.

Therefore, in the structure of the spring force adjusting portion according to the present invention and the hydraulic shock absorber in which the structure is embodied,
Except where necessary, only the same reference numerals are given in FIG. 1 except for the case where the configuration is the same as that of the conventional case described above, and detailed description thereof will be omitted. The explanation will focus on where it is.

That is, in the spring force adjusting portion structure according to the present invention, as shown in FIG. 1, an annular piston 42 constituting the jack portion 4 has a spring receiving side lower end in the drawing. A seal member 7 that slides on the outer circumference of the cylinder 1 is provided on the circumferential side, and a bearing that slides on the outer circumference of the cylinder 1 on the inner circumference side of an end of the annular piston 42 on the pressure chamber R side, which is an upper side in the drawing. A member 8 is provided, and a backup member 9 is provided behind the bearing member 8.

At this time, the seal member 7 is an oil seal, and is formed between the inner periphery of the annular piston 42 that communicates with the drain hole 1 c formed in the cylinder 1 and the outer periphery of the cylinder 1. It functions to prevent oil in the sliding gap (not shown) from leaking to the outside on the spring receiving side.

As described above, in the present invention, since the seal member 7 disposed between the inner periphery of the annular piston 42 and the outer periphery of the cylinder 1 is disposed on the inner periphery side of the annular piston 42, The thickness of the cylinder 1 can be reduced by the absence of the seal member 7, and as a result, the weight of the cylinder 1 can be reduced and the outer diameter can be reduced.

The bearing member 8 functions in cooperation with the lower bearing member B to secure a sliding stroke of the annular piston 42 with respect to the outer periphery of the cylinder 1, and the backup member 9 is used in this embodiment. In the embodiment, the bearing member 8 is made of an elastic material and functions so as to press the bearing member 8 against the outer periphery of the cylinder 1.

As a result, the bearing member 8 not only cooperates with the bearing member B as described above, but also functions as a so-called seal member by the pressing action of the backup member 9.

Since the bearing member 8 also functions as a sealing member, the sealing member 6 is arranged so as to be adjacent to the bearing member B1 in series as shown by a virtual line in FIG. Unlike the case of disposing, the seal member 6 does not need to be separately disposed.

As a result, in the present invention, the serial arrangement of the seal member 6 can be omitted, and accordingly, the annular piston 42
It is possible to reduce the length in the axial direction, which is the vertical direction in the figure, and to reduce the length in the axial direction of the annular piston 42, so that the basic length of the suspension spring 3 can be increased accordingly. Therefore, it is advantageous in that the range of adjusting the spring force of the suspension spring 3 is widened.

Incidentally, according to the present invention, a structure which does not damage so-called seals is adopted for the drain hole 1c formed in the cylinder 1.

That is, the opening end of the drain hole 1c on the outer peripheral side of the cylinder 1 is so-called tapered so that seals, that is, in the present invention, one bearing member 8 passes over the drain hole 1c. At this time, care is taken to prevent the bearing member 8 from being damaged.

On the other hand, in the illustrated embodiment, a seal member C serving as a dust seal is provided on the inner peripheral side of the lower end of the annular piston 42 so as to be in sliding contact with the outer periphery of the cylinder 1.
The seal member C and the seal member 7 above the seal member C
And the bearing member B described above.

Incidentally, in the annular housing 41 constituting the jack portion 4 together with the annular piston 42, an oil seal which is opposed to the outer periphery of the bottom portion 1a of the cylinder 1 is provided on the inner peripheral side of the so-called bottom end which is the upper end in the drawing. A member C1 is provided, and a seal member C2 which is the same oil seal as the oil seal facing the outer periphery of the annular piston 42 is provided on an inner peripheral side of a so-called open end which is a lower end in the figure.

It should be noted that the annular housing 41 is
Is fixed in a fixed state on the outer periphery of the cylinder 1, but is fixed in a fixed state by being locked to a flange portion 1d serving as a bottom end of the cylinder 1 in the figure.

The annular piston 42 also serves as a spring receiver for locking the upper end of the suspension spring 3, but in the drawing, the spring seat 31 is adjacent to the lower end.
The upper end of the suspension spring 3 is locked to the spring seat 31.

Therefore, the spring force adjusting portion structure according to the present invention formed as described above basically functions in the same manner as the conventional spring force adjusting portion structure shown in FIG. Will be.

That is, when the pressure oil is supplied to the pressure chamber R in the jack part 4 by the pumping operation due to the expansion and contraction of the hydraulic shock absorber, the annular piston 42 comes out of the annular housing 41, so that the suspension spring 3 The upper end is pushed down, and the spring force of the suspension spring 3 is adjusted to be high.

When the hydraulic shock absorber enters the predetermined extended state, the supply of the pressure oil to the pressure chamber R by the pumping operation is stopped, so that the spring force of the suspension spring 3 is maintained in the adjusted state. .

Further, when a high load acts on the suspension spring 3 and the hydraulic shock absorber is further compressed, the spring force of the suspension spring 3 is further adjusted to return the hydraulic shock absorber to a predetermined extended state. At this time, the annular piston 42 slides and largely projects from the inside of the annular housing 41.

That is, even in the spring force adjusting portion structure according to the present invention, when the load acting on the suspension spring 3 becomes excessive, the oil in the pressure chamber R is drained through the drain hole 1c opened in the cylinder 1. The so-called relief operation for returning to the inside of the cylinder 1 is performed, and the annular piston 42 is prevented from falling out of the annular housing 41, that is, being prevented from falling off.

In the above description, the case where the upper end of the suspension spring is raised and lowered in the hydraulic shock absorber in which the spring force adjusting portion structure according to the present invention is set upside down has been described as an example. In this case, the hydraulic shock absorber may be set upright, and the spring force adjusting portion structure according to the present invention may be provided so as to raise and lower the lower end of the suspension spring. In such a case, it is needless to say that a similar effect can be expected.

[0037]

As described above, according to the present invention, between the inner periphery of the annular piston constituting the jack for adjusting the spring force of the suspension spring and the outer periphery of the cylinder holding the jack, so to speak. Is disposed on the inner peripheral side of the annular piston, it is possible to reduce the thickness of the cylinder by the amount without disposing the seal member. This makes it possible to reduce the overall weight and the overall diameter of the vessel, for example, to improve the mountability on a vehicle.

According to the present invention, one of the bearing members, which cooperates with the other bearing member to ensure a sliding stroke of the annular piston with respect to the outer periphery of the cylinder, is formed of an elastic material. Since the bearing member is pressed against the outer periphery, the bearing member can function as a seal member.

Therefore, unlike the conventional case where the seal member is arranged adjacent to the bearing member in series, it is needless to say that a separate seal member need not be provided.
Since the series arrangement of the seal members can be omitted, the axial length of the annular piston can be reduced,
Therefore, as the length of the annular piston in the axial direction can be reduced, the basic length of the suspension spring can be increased, and the range of adjusting the spring force of the suspension spring can be expanded.

Further, with respect to the drain which is opened in the cylinder to realize the relief function in the jack portion, the opening end on the outer peripheral side of the cylinder is provided with a so-called taper so that the bearing member passes over the drain hole. Sometimes, it is possible to prevent the bearing member from being damaged.

As a result, according to the present invention, not only the height of the spring force of the suspension spring interposed in the hydraulic shock absorber can be adjusted, but also the hydraulic shock absorber, for example, a tower mounted on a vehicle. This is optimal for improving the versatility of the hydraulic shock absorber by improving the loadability and the cost.

[Brief description of the drawings]

FIG. 1 is a sectional view partially showing a spring force adjusting unit structure according to the present invention.

FIG. 2 is a cross-sectional view illustrating a hydraulic shock absorber including a conventional spring force adjusting unit structure.

FIG. 3 is a cross-sectional view partially showing a spring force adjusting unit structure in FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylinder 1a Bottom part 1b, 5a Flow path 1c Drain hole 1d Flange part 2 Piston rod 3 Suspension spring 4 Jack part 5 Guide rod 7, C1, C2 Oil seal seal member 8, B Bearing member 9 Backup member 31 Spring sheet 41 Annular housing 42 Annular piston C Seal member as dust seal P Pump chamber R Pressure chamber

Claims (1)

[Claims] An annular housing fixed to the outer periphery of a cylinder constituting a self-pumping type hydraulic shock absorber having a suspension spring interposed on the outer periphery, and sliding between an inner periphery of the annular housing and an outer periphery of the cylinder. An annular piston, which is also housed so as to divide the annular pressure chamber and abuts against one end of the suspension spring while also serving as a spring receiver. Along with projecting the annular piston from inside, when the amount of projection of the annular piston from inside the annular housing becomes greater than or equal to the setting, the oil in the pressure chamber is set to return to the cylinder through the drain hole opened in the cylinder. In the spring force adjusting portion structure, a seal member that is in sliding contact with the outer periphery of the cylinder is disposed on the inner peripheral side of the end of the annular piston that is the spring receiving side,
A bearing member that slides on the outer periphery of the cylinder is disposed on the inner peripheral side of an end of the annular piston that is the pressure chamber side, and a backup member is provided adjacent to the back of the bearing member. Spring force adjuster structure