JPH10281206A - Damping force regulation type shock absorber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To mount an actuator for regulating a damping force to a piston rod in a high-precise position and direction in spite of displacement in a mounting position from the piston rod of a bracket. SOLUTION: A damping force regulation type shock absorber comprises a fitting-in hole 21 formed in the periphery of the output shaft 3b of an actuator 3 for regulating a damping force eccentrically from an output shaft 3b: an adapter having a guide cylinder member 23 fitted in the outer periphery of the end of a piston rod 1 mountable in the fitting-in hole 21. Further, a bracket 5 is inserted in the central part of the piston rod 1 and fixed by means of a nut and fixes an actuator 3 body for regulating a damping force at an outer peripheral edge by means of a bolt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damping force adjusting type shock absorber for adjusting a damping force by a damping force adjusting actuator attached to a tip of a piston rod via a bracket.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional damping force-adjustable shock absorber. In this damping force-adjusting shock absorber, a cylinder (not shown) is partitioned into two oil chambers by a piston, and a damper attached to an upper end of the piston rod 1 is provided in a center hole 2 of the piston rod 1 having the piston at its tip. The control rod 4 driven by the force adjusting actuator 3 in the rotation direction or the axial direction is arranged.

[0003] A rotary valve or a needle valve is provided at the lower end of the control rod 4, and a predetermined amount of rotation or axial movement of the control rod 4 reduces an opening amount of an oil passage communicating with the two oil chambers. By adjusting, the damping force can be adjusted.

Further, in such a damping force adjusting type shock absorber, a D-cut portion 1a as shown in FIG.
, A D-cut hole 5a formed in the center of the bent bracket 5 is inserted, and two nuts 6 and 7 screwed around the outer periphery of the piston rod 1 press the periphery of the D-cut hole 5a of the bracket 5 with pressure. Is held. Further, the actuator 3 for damping force adjustment is provided at both ends of the bracket 5 by bolts 9 screwed into mounting screw holes 8 of the bracket 5.
Are fixed.

[0005] An O-ring 10 and a seal ring 11 are interposed between the inner periphery of the center hole 2 and the outer periphery of the upper end of the control rod 4.
The cylindrical output shaft 3b of the damping force adjusting actuator 3 is fitted to the small diameter end of the actuator.

[0006] The damping force adjusting actuator 3 comprises:
A first guide tube portion 3c having a shaft hole 3f for rotatably projecting the output shaft 3b is provided at the lower center of the main body, and concentric with the first guide tube portion 3c on the outer peripheral side thereof. A second guide cylinder portion 3d having a relationship and a short axial length
Having.

[0007] A seal member 12 in the form of a ring plate is inserted between the first guide cylinder 3c and the second guide cylinder 3d. In addition, control rod 4
When the output shaft 3b is inserted into the end, the piston rod 1
Is fitted between the first guide tube portion 3c and the second guide tube portion 3d, and the upper end surface thereof can contact the rail member 12.

[0008] In the damping force adjusting type shock absorber having such a configuration, when the damping force is adjusted, it is automatically or manually operated.
The damping force adjusting actuator 3 is driven by a predetermined amount, and the output shaft 3b is rotated or moved in the axial direction by a predetermined amount. Therefore, the control rod 4 connected to the output shaft 3b
Operate in the same direction, and the opening amount of an oil passage connecting two oil chambers partitioned in a cylinder by a piston is adjusted by a rotary valve or a needle valve (not shown).

For this reason, when the vehicle is subjected to vibration from the road surface while the vehicle is running, the desired damping force is generated in the shock absorber, and the vibration is absorbed to improve the riding comfort.

[0010]

However, in such a conventional damping force-adjustable shock absorber, a bracket 5 is fixed to the outer periphery of the upper part of the piston rod 1 at the time of assembling, and then the upper end of the piston rod 1 is fixed to the upper end thereof. Because the first guide cylindrical portion 3c of the damping force adjusting actuator 3 was fitted, and subsequently, the mounting piece 3a of the damping force adjusting actuator 3 was fixed to the bracket 5 using the bolt 9. The positions where the two bolts 9 are stopped and the positions where the D-cut portion 1a of the piston rod 1 and the D-cut hole 5a of the bracket 5 are fitted are shifted as shown in FIG. Output shaft 3b is eccentric with respect to the piston rod 1, and the output shaft 3b comes into contact with the inner periphery of the first guide cylinder portion 3c, so that the output Smooth rotation of 3b is a problem that is inhibited.

Further, the bracket 5 is used for the piston rod 1
If it is not possible to attach the actuator 3 in the proper direction (angle) with respect to the
As shown in FIG. 5, a play in the rotation direction R occurs between the output shaft 3b and the piston rod 1 attached to the control rod 4, and as a result, the control of the rotation or the axial movement of the control rod 4 is performed with high precision. There was a problem that it became impossible.

Further, if the mounting position of the damping force adjusting actuator 3 on the two mounting pieces 3a at the end of the bracket 5 is not on the same straight line with respect to the mounting position of the bracket 5 on the piston rod 1, the output shaft 3b interferes with the first guide cylinder 3c, which may cause damage.

In order to make the outer periphery of the end of the piston rod 1 abut against the inner periphery of the second guide cylinder 3d and to make the end face of the piston rod 1 adhere to the sealing material, the second guide cylinder 3d The inner diameter dimension is fixed, so that fitting and contact with another piston rod 1 having a different tip shape cannot be realized. If the outer diameter of the piston rod 1 is large, the piston rod 1 cannot be connected to the second guide cylinder 3d. There has been a problem that the outer circumference of the piston rod 1 must be cut so as to reduce the diameter for adaptation.

SUMMARY OF THE INVENTION The present invention solves the above-described problems, and it is possible to adjust the damping force with respect to the piston rod, even though the mounting position of the bracket with respect to the piston rod is shifted. The actuator can be mounted in a high-precision position and direction.Thus, the operation of the damping force adjustment actuator can be transmitted to the control rod with high accuracy to stably realize error-free damping force control and various pistons. An object of the present invention is to provide a damping force-adjustable shock absorber that can apply one type of damping force adjusting actuator common to the cross-sectional shape and dimensions of a rod, thereby improving economic efficiency.

[0015]

In order to achieve the above object, a damping force adjustable shock absorber according to the present invention is provided in a center hole of a piston rod, the damping force being attached to an upper end of the piston rod. A damping force-adjustable shock absorber having a control rod that is rotatably or axially movable by an adjusting actuator and that adjusts an opening amount of an oil passage communicating between two oil chambers defined by a piston in a cylinder. A fitting hole formed concentrically with the output shaft around the output shaft of the damping force adjusting actuator, is freely attachable to the fitting hole, and is fitted to the outer periphery of the end of the piston rod. A mounting adapter having a guide cylinder member is provided, and further, a center portion is inserted into the piston rod, the nut is fixed, and a damping force is adjusted at an outer end portion. The actuator body is provided with a bracket for bolting.

According to a second aspect of the present invention, in the shock absorber of the damping force adjusting type, a plurality of projections are provided in a cylindrical hole of the guide cylindrical member to closely support the outer periphery of the end of the piston rod press-fit into the cylindrical hole. It is provided.

In the shock absorber according to the third aspect of the present invention, the piston rod end press-fitted into the cylindrical hole of the guide cylindrical member has a D-cut shape or a two-sided width cut shape.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a damping force-adjustable shock absorber of the present invention in a partially broken manner.
Since the basic configuration is the same as that shown in FIG. 4, the same components will be described with the same reference numerals.

This damping force adjustable shock absorber is
The inside of the cylinder is partitioned into two oil chambers by a piston, and a damping force adjusting actuator 3 attached to an upper end of the piston rod 1 has a rotation direction or an axis in a center hole 2 of the piston rod 1 having the piston at the tip. The control rod 4 driven in the direction is arranged.

At the lower end of the control rod 4, a rotary valve or a needle valve is provided. By rotating or axially moving the control valve 4 by a predetermined amount, the opening of the oil passage communicating the two oil chambers is reduced. By adjusting, the damping force can be adjusted.

Further, D
A cut portion is provided, and a bracket 5
The two nuts 6 screwed into the outer periphery of the piston rod 1 are inserted into the D-cut holes 5a formed at the center of the piston rod 1.
7, the vicinity of the D-cut hole 5a of the bracket 5 is squeezed and held.

Further, at both ends of the bracket 5, mounting pieces 3a of the damping force adjusting actuator 3 are fixed by bolts 9 screwed into mounting screw holes 8 thereof. The mounting hole 3e formed in the mounting piece 3a and through which the bolt 9 is inserted is formed to have a diameter sufficiently larger than the shaft diameter of the bolt 9.

An O-ring 10 and a seal ring 11 are interposed between the inner periphery of the center hole 2 and the outer periphery of the upper end of the control rod 4.
The cylindrical output shaft 3b of the damping force adjusting actuator 3 is fitted to the small diameter end of the actuator.

Further, a stepped fitting hole 21 is formed on the lower surface of the main body of the damping force adjusting actuator 3 so as to surround the output shaft 3b and concentrically with respect to the output shaft 3b. A mounting adapter 26 having a guide cylinder member 23 is fitted in the fitting hole 21 so as to be freely fit around the outer periphery of the mounting adapter 26. In addition, a guide cylinder member 23 having a D-cut hole 22 as a cylinder hole as shown in FIG. The D-cut hole 22 is also concentric with the output shaft 3b. The output shaft 3b projects downward into the center hole 25 of the guide cylinder member 23 without interference.

As the mounting adapter 26, a guide cylinder member 23 having a D-cut hole 22 conforming to the outer diameter and shape of the upper end of the piston rod 1 is arbitrarily prepared. It can be mounted.

The D-cut hole 22 of the guide cylinder member 23
The flat portion, which is a cut portion of the piston rod 1, is crushed when the piston rod 1 is pressed into the flat portion, and this piston rod 1
Are provided densely.

FIG. 3 shows the guide cylinder member 23 of the mounting adapter 26 having a two-sided cut hole 22a as a cylindrical hole, which holds the upper end of the piston rod 1 having the two-sided cut surface. .

In such a damping force adjusting type shock absorber, as described above, the bracket 5 is attached to the piston rod 1 using the nuts 6 and 7, and the damping force adjusting actuator 3 is attached to the bracket 5. At this time,
The mounting adapter 26 is mounted in the fitting hole 21 of the damping force adjusting actuator 3 as described above, and the mounting adapter 2
6 is pressed into the outer periphery of the upper end of the piston rod 1 with the D cut hole 22 of the guide cylinder member 23. By doing so, the output shaft 3
b is inserted into the upper end of the small diameter portion of the control rod 4.

Before and after the press-fitting operation, a relatively large mounting hole 3e of the damping force adjusting actuator 3 is provided.
To the screw hole 8 at the end of the bracket 5 attached to the piston rod 1. By doing so, a concentric relationship among the piston rod 1, the guide cylinder member 21, the output shaft 3b, and the control rod 4 is ensured.

Further, since the mounting hole 3e has a large positioning range (margin) with respect to the screw hole 8, they can be easily matched. Therefore, the mounting error of the bracket 5 with respect to the piston rod 1 can be absorbed by the alignment of the mounting hole 3e with the screw hole 8.

As a result, by screwing the bolt 9 into the screw hole 8 through the mounting hole 3e, the piston rod 1, the bracket 5 and the damping force adjusting actuator 3 can be integrally fixed while maintaining the concentric relationship. .

Therefore, since the concentric relationship is obtained, the positional accuracy of the mounting holes 3e and the screw holes 8 of the two bolt 9 stoppers of the damping force adjusting actuator 3 is not required, and the assembling workability is improved. Improvement can be achieved.

Further, the output shaft 3b maintains the concentric relationship with the guide tube member 23 and, because the first guide tube portion as in the prior art is omitted, there is no interference around the output shaft 3b. There is no interference with, for example, the center hole 25 of the cylindrical member 23 or the center hole 2 of the piston rod 1. For this reason, even if there is some axis deviation between the output shaft 3b and the piston rod 1, interference with the center hole 2 does not occur.

As described above, the mounting of the damping force adjusting actuator 3 to the piston rod 1 is not performed between the piston rod 1 and the bracket 5 which is attached by causing backlash.

Therefore, the mounting of the piston rod 1 to the damping force adjusting actuator 3 can be realized with high precision without being affected by the backlash, and it is necessary to consider the difference between the two bolting positions of the bracket 5 and the concentric position. Disappears.

As a result, the damping force adjusting actuator 3
The rotation of the output shaft 3b can be transmitted to the control rod 4 with high accuracy. Therefore, the damping force adjustment accuracy is also improved.

Also, even if the bracket 5 is attached to the piston rod 1 with the rotation direction shifted, that is, even if the attachment accuracy is poor, the output shaft 3
The concentric relationship between b and the control rod 4 and the displacement in the rotational direction can be prevented.

Then, a guide cylinder member 23 that matches the size and shape of the upper end of the piston rod 1 is prepared and mounted in the fitting hole 21 of the damping force adjusting actuator 3 to adjust the damping force of the same specification and structure. Actuator 3
It can be used in common for various piston rods 1 and therefore, as in the prior art,
Cutting work etc. can be avoided.

As shown in FIGS. 2 and 3, the shape of the upper end of the piston rod 1 is a D-cut type or a two-sided width cut type. By fitting into the hole 22a, their relative mounting position and direction are determined by themselves, and the concentric relationship can be easily secured. Also,
A plurality of projections provided on each flat portion of each D-cut hole 22 and the two-face width cut hole 22a can maintain the concentric position and reliably prevent the relative position from shifting.

[0040]

As described above, according to the first aspect of the present invention, in the center hole of the piston rod, the damping force adjusting actuator attached to the upper end of the piston rod is rotatable or axially movable. An output shaft of a damping force adjusting actuator is provided on a damping force adjustable shock absorber having a control rod that is freely provided and adjusts an opening amount of an oil passage communicating between two oil chambers defined by a piston in a cylinder. A fitting hole formed concentrically with respect to the output shaft and a mounting adapter having a guide cylinder member that is attachable to the fitting hole and fitted around the outer periphery of the piston rod end are provided around the periphery, The bracket is configured so that the center portion is inserted into the piston rod, the nut is fixed to the piston rod, and a bracket for bolting the damping force adjusting actuator body is provided at the outer end. Since the, despite it is the mounting position deviation of the piston rod of the bracket, based on the piston rod, it is possible to attach the damping force adjustment actuator in the position and direction of the high-precision hand. Therefore, the operation of the damping force adjusting actuator can be transmitted to the control rod with high accuracy, and the damping force control without error can be stably realized. In addition, one kind of common for the cross-sectional shapes and dimensions of various piston rods. An actuator for adjusting the damping force can be applied, which has the effect of improving economy.

According to the second aspect of the present invention, a plurality of projections are provided in the cylindrical hole of the guide cylindrical member so as to closely support the outer periphery of the end of the piston rod which is press-fitted into the cylindrical hole. When the piston rod end and the guide cylinder member of the damping force adjusting actuator are centered, they can be securely and firmly held together, thereby making the output shaft of the damping force adjusting actuator concentric with the control rod. The effect is obtained that the relationship and the connection can be reliably and stably maintained.

According to the third aspect of the present invention, the end of the piston rod, which is press-fitted into the cylindrical hole of the guide cylindrical member, is configured to have a D-cut shape or a two-sided width cut shape.
The effect that the position in the rotation direction of the piston rod with respect to the guide cylinder member, that is, the relationship between the output shaft and the opening amount of the rotary valve for adjusting the damping force opened and closed by the control rod can be set with high accuracy without causing a deviation. Is obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a damping force-adjustable shock absorber according to an embodiment of the present invention, partially cut away.

FIG. 2 is a cross-sectional view taken along line AA of FIG.

3 is a cross-sectional view of a portion corresponding to the line AA in FIG. 1 showing another embodiment of the fitting structure of the guide cylinder member to the piston rod in FIG. 1;

FIG. 4 is a sectional view showing a conventional damping force-adjustable shock absorber in a partially broken manner.

FIG. 5 is a sectional view taken along line BB of FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piston rod 2 Center hole 3 Damping force adjusting actuator 3b Output shaft 4 Control rod 5 Bracket 6,7 Nut 9 Bolt 21 Fitting hole 22 D-cut hole (cylindrical hole) 22a Double-width cut hole (cylindrical hole) 23 Guide Tube member 24 Projection 26 Mounting adapter

Claims (3)

[Claims] 1. A piston rod is provided in a center hole of a piston rod so as to be rotatable or axially movable by a damping force adjusting actuator attached to an upper end of the piston rod, and is defined by a piston in a cylinder. In a damping force-adjustable shock absorber equipped with a control rod for adjusting the opening amount of an oil passage communicating with
A fitting hole formed concentrically with the output shaft around the output shaft of the damping force adjusting actuator, and a guide cylinder member that is freely attachable to the fitting hole and fitted to the outer periphery of the piston rod end. A damping force-adjustable shock absorber, comprising: a mounting adapter having the same; and a bracket for inserting a central portion through a piston rod, fixing the nut, and fixing an outer end portion with a bolt for fixing an actuator body for damping force adjustment. 2. The damping device according to claim 1, wherein a plurality of protrusions are provided in a cylindrical hole of the guide cylindrical member so as to elastically hold an outer periphery of a piston rod end pressed into the cylindrical hole. Force adjustable shock absorber. 3. The damping force-adjustable shock absorber according to claim 1, wherein a piston rod end press-fitted into a cylindrical hole of the guide cylindrical member has a D-cut shape or a two-sided width cut shape.