JPH0429144Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a variable damping force hydraulic shock absorber that is disposed between a vehicle body and an axle of an automobile or the like.

BACKGROUND TECHNOLOGY Conventionally, in order to improve the ride comfort or running stability of automobiles, hydraulic fluid is used between the divided liquid chambers of a hydraulic shock absorber, which is filled with hydraulic fluid between the vehicle body and the axle of an automobile. A damping force generating means is provided that generates a damping force by restricting the flow of the damping force, and a regulator that variably controls the amount of hydraulic fluid passing through the damping force generating means is rotated by a predetermined angle by the driving force of the motor. A hydraulic shock absorber capable of adjusting the damping force is known (for example, Japanese Patent Laid-Open No. 59-80546). FIG. 4 is a sectional view of a main part showing the structure of such a conventional hydraulic shock absorber T, and the structure is as follows. That is, 9 is a cylinder filled with hydraulic fluid, 10
is a piston rod that protrudes toward the other end of the cylinder 9 while one end of the cylinder 9 is sealed.
A piston 11 is slidably inserted into the cylinder 9, and the piston 11 separates the inside of the cylinder 9 into two chambers, an upper liquid chamber 12 and a lower liquid chamber 13. This piston 11 is provided with a damping force generating means 1 that generates flow resistance in the working fluid displacing and circulating the upper and lower liquid chambers 12 and 13.
4 are provided. 15 is piston rod 10
This is a cylindrical stud that connects the piston 11 and the regulator accommodating part 16, and the lower liquid chamber 1 is contained inside the stud 15.
Through holes 17 in the axial direction communicating with each other are formed respectively. Also, the cylindrical wall portion 15 of this stud 15
As shown in FIG. 5, orifices 1 having mutually different opening areas and communicating with the upper liquid chamber 12 are arranged at predetermined intervals in the circumferential direction, as shown in FIG.
8, 19, and 20 are drilled. Further, in the adjuster accommodating portion 16 of the stud 15, there is rotatably accommodated an adjuster 8 which is rotatably driven by a motor 4 housed in the hollow portion of the piston rod 10. An axial through hole 22 that opens and communicates with the lower liquid chamber 13, and a communication hole 23 that can selectively communicate with any one of the orifices 18, 19, and 20 provided in the stud 15. are formed respectively. The input end of the motor 4 is connected to a motor drive circuit (not shown) via harnesses 24, 24.
A drive shaft 4a of the motor 4 is connected to an adjuster 8 to rotate the adjuster 8.

According to the configuration of the hydraulic shock absorber T as described above, the vertical movement of the piston rod 10 accompanied by the piston 11 causes the damping force generating means 14 provided on the piston 11 to
While receiving resistance from the spring force of the valve plates 26, 26 that close one open end of the through oil passages 25, 25, the upper and lower A desired damping force can be ensured by displacing and circulating the working fluid between the respective fluid chambers 12 and 13.

On the other hand, by operating a changeover switch (not shown) to select an arbitrary damping force setting position, for example, one of high, medium, and low damping force setting positions, depending on the driving situation of the automobile, etc. The drive circuit for the motor 4 receives this selected selection signal and supplies a drive current to the motor 4. Then motor 4 rotates,
The adjuster 8 is driven to rotate. When the communicating hole 23 of the adjuster 8 and any one of the orifices 18, 19, and 20 are brought into open communication, the rotation of the adjuster 8 is stopped at that position. For this reason, a part of the working fluid flowing between the upper and lower liquid chambers 12 and 13 is transferred to the orifices 18, 19, 2.
0 through the communication hole 23, the damping force obtained by the damping force generating means 14 can be adjusted to ensure a desired damping force.

Problems to be Solved by the Invention However, in the case of such a conventional variable damping force hydraulic shock absorber, the adjuster 8 is rotated by operating a changeover switch (not shown) depending on the driving conditions of the vehicle, etc. Communication hole 23 of regulator 8 and orifice 1
8, 19, and 20, the communication hole 23 of the adjuster temporarily connects with the orifice 18, 20 when the adjuster 8 rotates.
19 and 20, the damping force of the hydraulic shock absorber becomes temporarily high, resulting in poor riding comfort. That is, as shown in FIG. 6, by rotating the adjuster 8 in the direction of arrow A (counterclockwise), the communicating hole 23 of the adjuster 8 is connected to the orifice 19 provided in the passage wall 15a of the stud 15. When trying to switch from orifice 18 to
That is, the communication hole 23 is located at an intermediate position between the orifice 19 and the orifice 18, and both orifices 1
A state occurs in which there is no communication with either 9 or 18. Under such conditions, the hydraulic fluid bypass passage consisting of the communication hole 23 and the orifice 19 or 18 is completely blocked, and therefore the damping force of the hydraulic shock absorber T becomes temporarily high. This will result in In this way, when the damping force temporarily increases, vibrations caused by uneven road surfaces are transmitted to the sprung portion of the vehicle body, giving the occupants an unpleasant uplifting feeling, resulting in a worsening of ride comfort. There was a problem.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a hydraulic shock absorber that can overcome the above-mentioned conventional problems and that can smoothly and steplessly adjust the damping force.

Means for Solving the Problem A damping force generating means that generates a damping force by restricting the flow of the hydraulic fluid between the partitioned liquid chambers of the hydraulic shock absorber filled with the hydraulic fluid, and a damping force generating means that is driven by a motor,
In a variable damping force hydraulic shock absorber comprising a regulator that variably controls the amount of working fluid passing through the damping force generating means, the regulator is divided into an upper regulator and a lower regulator each having a cylindrical shape. The upper adjuster is connected to the drive shaft of the motor, while the lower adjuster is provided so as to be non-rotatable and movable up and down, and biased toward the upper adjuster by a spring, so that the upper adjuster and the lower adjuster are connected to each other. The connecting portions of the damping force generating means are formed into a sawtooth shape that meshes with each other, and by rotating the upper adjuster, a communication hole for variably controlling the amount of liquid passing through the damping force generating means is formed at the connecting portion with the lower adjuster. It is set as.

Operation When a drive current is applied to the motor in order to adjust the damping force of the hydraulic shock absorber, the upper adjuster rotates by a predetermined angle. Then, due to the action of the serrated joint between the upper adjuster and the lower adjuster, the lower adjuster moves downward a certain distance against the elastic force of the spring.
Therefore, the opening area of the joint between the upper adjuster and the lower adjuster changes steplessly in accordance with the rotation angle of the motor. Since the substantially diamond-shaped communication hole is opened and the working fluid is exchanged and circulated between the upper and lower liquid chambers in the cylinder, the damping force can be smoothly adjusted.

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings. In the sectional view shown in FIG. 1, the same reference numerals are given to the same components as the conventional components. That is, with one end of the cylinder 9 filled with hydraulic fluid sealed, a rod orifice 1 is installed on the side wall of the piston rod 10 that protrudes toward the other end of the cylinder 9.
0a is drilled. On the other hand, an outer circumferential groove 15d and an inner circumferential groove 15e are respectively formed in the circumferential direction in the outer circumferential part 15b and inner circumferential part 15c of the substantially cylindrical stud 15 that connects the piston rod 10 and the piston 11, at the portions opposing the rod orifice 10a. ing. Furthermore, the stud 15 has the outer circumferential groove 15d and the inner circumferential groove 1.
A stud orifice 15f is provided which communicates with 5e. Inside this stud 15 is a regulator housing section 16 and a lower liquid chamber 13 inside the regulator housing section 16 and a lower liquid chamber 13.
An axial through hole 17 is formed to communicate with the two. An upper adjuster 8a is disposed inside the adjuster accommodating portion 16.
The adjuster 8 is housed therein, and is divided into a lower adjuster 8b and a lower adjuster 8b. A drive shaft 4a of a motor 4 is connected to the upper adjuster 8a, and as the motor 4 rotates, the upper adjuster 8a moves into the adjuster housing 16.
It is rotatable inside. Below the other lower adjuster 8b is a stepped portion 15g of the stud 15.
A spring 30 whose lower end is supported is inserted, and the lower adjuster 8b receiving the spring force of the spring 30 is loosely fitted in the adjuster accommodating portion 16 of the stud so as to be non-rotatable but movable up and down. ing. 3
Reference numeral 1 designates a rotation prevention pin of the lower adjuster 8b, one end of which is fixed to the stud 15 side.

FIG. 2 shows the upper adjuster 8a, and FIG. 3 shows the lower adjuster 8b as perspective views of essential parts. That is, both the upper adjuster 8a and the lower adjuster 8b are cylindrical, and the lower end of the upper adjuster 8a, which corresponds to the joint between the two, has saw teeth 32, 32, and the upper end of the lower adjuster 8b has saw teeth. 33, 33 are formed, and the saw teeth 32, 32 and the saw teeth 33, 3 are formed.
3 are shaped so that they mesh with each other. A slit-like notch 34 is formed in the lower part of the lower adjuster 8b, and the tip of the rotation prevention pin 31 is inserted into this slit-like notch 34.

Using the hydraulic shock absorber T as described above, the damping force can be set at any desired position depending on the driving conditions of the vehicle, etc.
The operation when selecting by operating a changeover switch (not shown) will be described below. When the motor 4 rotates in response to one selection signal selected by the changeover switch, the upper adjuster 8a also rotates via the drive shaft 4a of the motor 4. The joint between the upper adjuster 8a and the lower adjuster 8b is connected to the saw teeth 32, 32.
Since the saw teeth 33 and 33 are in a state of meshing with each other, the upper adjuster 8a is moved in the direction indicated by the arrow B in FIG.
By rotating the saw teeth 32, 3 in the direction of
2 pushes the lower adjuster 8b downward against the spring force of the spring 30. As a result, the upper adjuster 8a
As shown in FIG. 1, a hydraulic fluid communication hole 35 having a substantially deformed shape is opened at the joint between the lower regulator 8b and the lower regulator 8b. The opening area of the communication hole 35 changes steplessly in accordance with the rotation angle of the upper adjuster 8a.
The rotation angle of the upper adjuster 8b may be determined so that the opening area of the upper adjuster 8b becomes a desired size.

When the communication hole 35 is opened at the joint between the upper regulator 8a and the lower regulator 8b as described above, the upper liquid chamber 1
2 and the lower liquid chamber 13 are connected to the rod orifice 1.
0a, outer circumferential groove 15d of stud 15, stud orifice 15f, inner circumferential groove 15e of stud 15,
Since the openings communicate through the communication hole 35 and the through hole 17, a part of the hydraulic fluid flowing between the upper and lower liquid chambers 12 and 13 can be bypassed to obtain a desired damping force. can.

Effects of the Invention As is clear from the above explanation, according to the present invention, the adjuster to be housed inside the stud is divided into a cylindrical upper adjuster and a lower adjuster, and the upper adjuster is connected to the motor. While connected to the drive shaft of
The lower adjuster is provided so as to be non-rotatable but movable up and down, and is biased toward the upper adjuster by a spring, and the joint portions of the upper adjuster and the lower adjuster are formed into a sawtooth shape that meshes with each other, thereby adjusting the upper part. By rotating the child, a communication hole is formed at the joint with the lower adjuster to variably control the amount of liquid passing through the damping force generating means, so the damping force of the hydraulic shock absorber can be smoothly adjusted. be able to. That is, the area of the hydraulic fluid communication hole formed at the joint between the upper regulator and the lower regulator can be determined by the rotation angle of the motor drive shaft that rotationally drives the upper regulator. Since the area of the communication hole can be changed steplessly, the damping force of the hydraulic shock absorber can also be changed smoothly. Therefore, there is no risk that the damping force will temporarily increase in the middle of adjusting the damping force, and the rider will not feel an unpleasant uplifting feeling due to vibrations caused by uneven road surfaces, improving ride comfort. can be improved.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of essential parts showing an embodiment of a variable damping force type hydraulic shock absorber according to the present invention, Fig. 2 is a perspective view showing the structure of the upper adjuster, and Fig. 3 is the structure of the lower adjuster. FIG. 4 is a sectional view of main parts showing the structure of a conventional hydraulic shock absorber, FIG. 5 is a sectional view taken along the line -- in FIG. 4, and FIG. FIG. 3 is a cross-sectional view at a similar position. 4...Motor, 8...Adjuster, 8a...Upper adjuster, 8b...Lower adjuster, 9...Cylinder, 1
0... Piston rod, 11... Piston, 12
... Upper liquid chamber, 13 ... Lower liquid chamber, 14 ... Damping force generating means, 15 ... Stud, 30 ... Spring, 32, 33 ... Sawtooth, 35 ... Communication hole.

Claims (1)

[Claims for Utility Model Registration] A damping force generating means that generates a damping force by restricting the flow of hydraulic fluid between partitioned liquid chambers of a hydraulic shock absorber filled with hydraulic fluid, and a damping force generating means driven by a motor;
A variable damping force hydraulic shock absorber comprising a regulator that variably controls the amount of hydraulic fluid passing through the damping force generating means, wherein the regulator is divided into an upper regulator and a lower regulator each having a cylindrical shape. The upper adjuster is connected to the drive shaft of the motor, while the lower adjuster is provided so as to be non-rotatable and movable up and down, and biased toward the upper adjuster by a spring, so that the upper adjuster and the lower adjuster are connected to each other. The connecting portions of the damping force generating means are formed into a sawtooth shape that meshes with each other, and by rotating the upper adjuster, a communication hole for variably controlling the amount of liquid passing through the damping force generating means is formed at the connecting portion with the lower adjuster. A variable damping force hydraulic shock absorber.