JPS5912440Y2 - Shock absorber damping force adjustment device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a damping force adjusting device for a shock absorber in which an orifice provided in a piston rod is made variable by external operation, thereby making it possible to switch the damping force into multiple stages.

A conventional damping force adjustment method of this kind is to make a fixed orifice in the piston variable, and the oil passage area of the lateral hole of the piston rod is made variable by the tip of the push rod.

To actuate the push rod, the guide is rotated by an external operation so that the guide is moved by the threaded portion, and at this time, the stopper in contact with the guide is moved.

This stopper is in contact with the push rod, and as the guide rotates and moves linearly, the push rod moves via the stopper, causing the tip at the tip to approach or move away from the end of the through hole, thereby causing the tip to move laterally. Change the oil passing area of the hole.

In other words, by externally moving the tip of the push rod, the fixed orifice is varied and the damping force is adjusted in accordance with the opening area of this orifice.

However, this conventional method is complicated due to the large number of parts, requires work to correct the position of the piston rod horizontal hole and the tip due to tolerances of the piston rod, push rod, and other parts, and the adjustment mechanism of the external guide is large and causes shock. Does it have the disadvantage of increasing the basic length of the absorber itself? .

For this reason, the applicant has developed a damping force adjustment device for shock absorbers that does not require compact position correction, and has filed an application for utility model registration (Utility Model Application No. 171955-1982).
.

However, in the damping force adjustment device described above, a slight gap is formed between the sleeve and the inner wall of the vertical hole so that the sleeve rotates smoothly within the vertical hole, and a pressure difference is generated before and after the orifice when the sleeve is expanded. A part of the oil in the liquid chamber on the high pressure side flows out from the side hole to the end of the sleeve through this gap.

For this reason, the hydraulic pressure flowing out to this end acts on the sleeve in the direction of withdrawal, creating the risk of the sleeve coming off from the rotary rod.This causes the opposing positions of the orifice and the horizontal hole to shift, resulting in the desired damping. It becomes impossible to obtain power.

Therefore, the present applicant further improved this and developed a shock absorber damping force adjustment device that allows oil on the high pressure side to escape and not act on the sleeve even if a differential pressure occurs before and after the orifice. No. 52-160697).

In this newly developed damping force adjustment device, a vertical hole that opens into the lower fluid chamber is bored in the piston rod in the axial direction, and a horizontal hole that communicates this vertical hole with the upper fluid chamber is bored in the lateral direction. A rotary rod that interlocks with an external driving member is rotatably inserted into the vertical hole, and a sleeve is press-fitted to the tip of the rotary rod via serrations.
The sleeve rotates in the vertical hole together with the rotary rod, and its body has multiple orifices facing the horizontal hole, and the damping force can be arbitrarily selected according to the inner diameter of these orifices. In addition, one or more through holes are bored in the sleeve at a position above the orifice to provide communication between the back side of the sleeve and the vertical holes.

However, even with such an improved damping force adjustment device, it is necessary to precisely finish the inner diameter of the piston rod's sleeve installation part, and inspection is difficult because the sleeve installation position is deep in the vertical hole. Furthermore, the outer diameter of the sleeve must be strictly specified, making processing difficult.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a damping force adjusting device for a shock absorber that allows easy maintenance and inspection of the orifice from outside the piston rod, is simple to process, and is inexpensive.

An example of implementing the present invention will be described below with reference to the drawings.

The shock absorber main body is the same as the conventional one, for example, an inner cylinder 2 is disposed coaxially within an outer cylinder 1, and an oil chamber 3 is defined between these cylinders 1 and 2, and this oil chamber 3 is connected to a head 4, 5 is sealed.

A piston rod 7 is slidably inserted into the inner cylinder 2 via a piston 6.
penetrates the head 4 and protrudes to the outside, and the piston rod 7
The eye 8 at the tip is fixed to the vehicle body side, and the eye 9 at the bottom 5 side
is connected to the axle side.

The inner cylinder 2 is divided into an upper oil chamber 10 and a lower oil chamber 11 through a piston 6, and the lower oil chamber 11 is connected to an outer oil chamber 3 through a base valve at the bottom of the inner cylinder.
It communicates with

An oil passage 12 is vertically bored in the piston 6 to form upper and lower oil chambers 10.
11, and the upper end of this oil passage 12 is opened and closed by a valve 13, which is held on the piston 6 side by a spring 14 and a valve retainer 15.

The tip of the piston rod 7 passes through the center of the piston 6 and is screwed thereto, and a vertical hole 16 vertically bored in the piston rod 7 opens toward the lower oil chamber 11 side.

A horizontal hole 17 is bored in the piston rod 7 in the radial direction, and this horizontal hole 17 connects the upper oil chamber 10 and the vertical hole 1 in the piston rod 7.
6 are connected.

A rotary rod 18 is installed in the vertical hole 16 of the piston rod 7.
is rotatably inserted, and the upper part of the rotary rod 18 protrudes outside from the upper end of the piston rod 7 so that it can be rotated from the outside.

An arbitrary gap is formed between the outer circumference of the rotary rod 18 and the inner circumference of the vertical hole 16 to allow the flow of hydraulic oil.

A horizontal plate 19' as shown in FIGS. 2 and 3 is fixed to the lower end of the piston rod 7 by caulking or other methods, and a vertical hole closing portion 19 is formed therein.

A through hole 20 is bored at the end of this plate 19'.

The upper surface of the plate 19' includes a rod portion 21 and a flange portion 2.
A T-shaped sleeve 23 consisting of two is placed and brought into contact,
The outer periphery of the flange portion 22 of this sleeve 23 has a plurality of U-shaped orifices with different inner diameters as shown in FIG.
Semicircular etc. notches 24 a, 24 b, 24 C...
...24 n is notched, and these notches 24a, 24
b...24n selectively opens into the through hole 20 of the plate 19'.

When any of the notches 24a, 24b...24n opens into the through hole 20, the notches 24a, 2
4b...24 The shape of the orifice for generating damping force is determined according to the size of n.

Therefore, the through hole 20 is provided as shown in FIG. 3, and the notches 24a,
24b...24n may be provided on the sleeve 23 side as shown in FIG. 5, but as shown in FIG.
'A plurality of orifices 25a, 25b with different diameters are provided on the outer periphery of the
, 25C .
5 b...25 n is this notch 2
6, and the damping force may be generated according to the diameter of the orifice.

A triangular, square, or other polygonal stop hole 27 is vertically bored in the rod portion 21 of the sleeve 23, and a polygonal rod 28 with a shape corresponding to the stop hole 27 is formed in the stop hole 27.
This rod 28 is integrally connected to the tip of the rotary rod 18, so that when the rotary rod 18 is rotated, the sleeve 23 is rotated in the same direction via the rod 28.

Further, a spring 29 is interposed between the sleeve 23 and the lower rerod 18 to constantly press the sleeve 23 against the plate 19'.

Next, we will discuss the operation.

When the vehicle body is running and there is vibration or impact from the road surface, the shock absorber absorbs and alleviates this energy. For example, when the piston rod 7 extends, the piston 6
rises, the upper oil chamber is compressed, and the lower oil chamber 11 expands. At this time, the oil in the oil chamber 3 flows out into the lower oil chamber 11 via the base valve, and the oil in the upper oil chamber flows into the piston rod 7. Side hole 1
7. From the vertical hole 16, it flows into the lower oil chamber 11 through the notch 24a of the sleeve 23 and the hole 20 of the washer 19, and at this time, the notch 24a provides a damping force of a magnitude corresponding to its inner diameter. When the piston rod 7 and piston 6 descend, the upper oil chamber 10 expands and the lower oil chamber 1
1 is compressed, and at this time, the oil in the lower oil chamber 11 pushes open the valve 13 through the through hole 12 of the piston 6 and flows out into the upper oil chamber.
A predetermined damping force can be obtained by the valve 13.

By the way, in motorcycles and the like, it is preferable to arbitrarily change the damping force when the piston rod is raised depending on the loaded load, the weight of the driver, the road surface conditions on which the motorcycle is traveling, etc.

For this purpose, if the sleeve 23 is rotated via the rotary rod 18 by an external operation, and whichever of the desired notches 24a, 24b, . . . , 24n is opposed to the hole 20 of the plate 19', It is possible to freely select the damping force according to the notch 24a etc. in accordance with the above conditions.

In this case, as shown in FIGS. 4 and 6, a notch 26 is provided on the sleeve 23 side, and a plurality of orifices 25cl, 25b, . . . 25n are formed on the plate 19' side. Even if the notch 26 is opposed to one of the plate-side orifices 251 by rotating the notch 23 to obtain a damping force corresponding to that orifice, the operation and effect are exactly the same.

In the above device, by disposing the vertical hole closing part 19 and the sleeve 23 at the lower end of the piston rod 6, it is possible to easily maintain and inspect the condition of the orifice etc. from the outside of the piston rod. Since the inner and outer diameter tolerances can be set roughly, machining is easy and manufacturing costs can be reduced.

Similarly, the outer diameter tolerance of the sleeve can be made rough, and if it is made of synthetic resin, it can be molded, making it easier to process and significantly lower manufacturing costs than conventional machined products. It is possible to go down.

Furthermore, a spring is interposed between the end face of the rotary rod and the end face of the sleeve, and the elastic force of this spring keeps the vertical hole closing part and the sleeve sliding surface in close contact at all times. Even if the contact between the sliding surfaces is poor due to an error, the sleeve is forcibly pressed against the vertical hole closing part by the spring, and is completely unaffected by errors in assembly and processing, preventing the occurrence of backlash. , it becomes possible to eliminate leakage from the sliding surface.

Therefore, since the damping force only depends on the orifice drilled in the sleeve, there is no variation in the damping force, and desired damping force characteristics can be reliably obtained.

Furthermore, since the sleeve is pressed by a spring, no separate positioning mechanism is required, and the structure is simplified accordingly.

[Brief explanation of the drawing]

The attached drawings relate to embodiments of the present invention, and FIG. 1 is a partially cutaway vertical side view of the shock absorber, FIG. 2 is a partially enlarged vertical side view of FIG. 1, and FIG. 3 is a biston rod and washer. FIG. 4 is a front view of a piston rod and plate according to another embodiment, FIG. 5 is a front view of a sleeve,
FIG. 6 is a front view of a sleeve according to another embodiment. 2...Cylinder, 6...Piston, 7
... Piston rod, 10 ... Upper oil chamber, 11 ... Lower oil chamber, 16 ... Vertical hole, 17 ... Horizontal hole, 18...Rotary rod, 19...Vertical hole closing part, 20, 26...
...Through hole, 21...Rod part, 22...
...Flange part, 23...Sleeve, 24a
,24 b...24 n, 25 a, 25
b...25 n...Orifice, 2
9... Spring.

Claims (5)

[Scope of utility model registration request] (1) A piston serving as a piston rod is slidably inserted into a cylinder and defines an upper oil chamber and a lower oil chamber within the cylinder, and the piston rod has a vertical hole and a horizontal hole that communicates the upper oil chamber and lower oil chamber. In the shock absorber which has a hole and a rotary rod rotatably inserted into the vertical hole, a vertical hole closing part is formed at the opening of the vertical hole at the tip of the piston rod, and a vertical hole closing part is formed on the vertical hole closing part. A sleeve is rotatably brought into contact with the rotary rod, and a rotary rod is fitted into the sleeve so as to rotate integrally therewith, and a spring is interposed between the end face of the rotary rod and the end face of the sleeve to bring the vertical hole closing portion and the sleeve into close contact. A through hole is provided in one of the vertical hole closing portion and the sleeve, and a plurality of orifices with different opening areas are provided in the other, or one of the orifices is freely selected by rotating the rotary rod and the sleeve by an external operation. Shock absorber damping force adjustment device. (2) The damping force adjusting device for a shock absorber according to claim 1, wherein the vertical hole closing portion has one through hole and the sleeve has a plurality of notches with different opening areas. (3) The damping force adjustment device for a shock absorber according to claim 1, which is a registered utility model, in which a plurality of orifices of different diameters are formed in the vertical hole closing portion and one notch is formed in the sleeve. (4) The shock absorber damping force adjusting device according to claim 1, wherein the sleeve comprises a rod portion and a flange portion. (5) The damping force adjusting device for a shock absorber according to claim 4, which is a utility model, wherein a notch is provided in the flange portion.