JPH08219167A - Connecting structure of rotary shaft - Google Patents

Abstract

PURPOSE: To provide a damping force variable-type hydraulic shock absorber in which a control rod and an output shaft are reliably connected to each other by making their axes coincide with each other without using other parts such as a bearing bush. CONSTITUTION: The tip of a control rod 25 is formed into a diameter smaller than that of an output shaft 26, a width across flat part 27 is formed on a small-diameter part 25a, a fitting hole 29 to which the small-diameter part 25a is to be fitted and a slit 28 deeper than the fitting hole 29, and with which the width across fit part 27 is to be engaged are formed on the tip of the output shaft 26, the output shaft 26 and the control rod 25 are rotated and engaged with each other by the width across fit part 27 and the slit 28 and connected to each other by being centered by the small-diameter part 25a and the fitting hole 29.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating shaft connecting structure for connecting, for example, a control rod on the damping force varying mechanism side and an output shaft of a damping force varying actuator.

[0002]

2. Description of the Related Art For example, like a hydraulic shock absorber mounted on a suspension of a vehicle, a damping force variable mechanism is used to variably adjust the damping force according to road surface conditions such as city driving and bad road driving. A variable damping force type hydraulic shock absorber provided with is generally known.

An actuator for variably controlling the damping force varying mechanism is provided in the hydraulic shock absorber in a state of being connected to the damping force varying mechanism.

That is, the output shaft of the actuator is connected to the control rod of the damping force varying mechanism to transmit the rotational force of the actuator to the damping force varying mechanism, and the damping force varying mechanism is defined in the cylinder by the piston. The damping force is made variable by controlling the area of the passage that connects the two chambers.

As for the connecting structure of the output shaft of the actuator and the control rod of the damping force varying mechanism, the one described in Japanese Utility Model Laid-Open No. 62-73135 is known. According to this, as shown in FIG. 4, a piston rod 5 which is connected to a piston that defines the inside of a cylinder (not shown) into two chambers is formed hollow, and the damping force variable mechanism is formed in the piston rod 5. The control rod 4 is provided so as to penetrate in the axial direction, and the control rod 4 has a split groove portion in which the width across flat portion 6 is formed at the tip of the output shaft 3 as the rotary shaft of the actuator 1 side. 7 so that the output shaft 3 and the control rod 4 rotate integrally, the control operation of the actuator 1 is transmitted to the damping force variable mechanism, and is defined in the cylinder by the piston. The area of the passage that connects the two chambers is controlled.

However, the connection between the output shaft 3 and the control rod 4 in the prior art is such that the width across flat portion 6 on the control rod 4 side and the split groove portion 7 on the output shaft 3 side.
Since it is performed only by fitting the control rod 4 and the output shaft 3, the control rod 4 may be misaligned in the direction of the width across flats of the width across flats 6; In addition, the fulcrum formed for transmitting the rotational torque of the flat width portion 6 deviates from the axial center, so that the rotational load on the actuator 1 increases and the durability of the actuator 1 deteriorates. there were.

Therefore, in order to solve this problem, for example, in the conventional damping force variable type hydraulic shock absorber disclosed in Japanese Utility Model Laid-Open No. 5-1044, the connecting structure of the rotating shafts includes a control rod and a piston rod. There is a type in which a bearing bush is fitted in a gap between the inner wall portion and the control rod to center the control rod.

[0008]

However, in such a conventional rotating shaft connecting structure, a separate part called a bearing bush is used for centering the control rod, which increases the number of parts. At the same time, the number of assembling steps will be increased.

In view of the above problems, the present invention has been made in view of the above problems.
An object of the present invention is to provide a rotating shaft connecting structure capable of surely connecting the control rod and the output shaft with their axes aligned with each other without using a separate component such as a bearing bush.

[0010]

According to the rotating shaft connecting structure of the present invention, the tip of one of the output shaft and the control rod is formed to have a smaller diameter than the other, and the two-width portion is formed in the small diameter portion. On the other hand, at the other end, a fitting hole into which the small-diameter portion is fitted and a slit deeper than the fitting hole and into which the two-face width portion engages are formed. It is characterized in that the width portion is rotationally engaged with the slit and the small diameter portion is centered and connected with the fitting hole.

[0011]

The double-width portion is fitted into the slit to transmit the rotational force of the output shaft via the control rod to, for example, the damping force varying mechanism, and the small diameter portion of the control rod is fitted into the fitting hole. Center the output shaft with respect to the control rod without using a separate part.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment in which the present invention is applied to a variable damping force type hydraulic shock absorber will be described below with reference to the accompanying drawings.

FIG. 1 is a partial sectional side view showing the overall construction of the variable damping force type hydraulic shock absorber of the present embodiment, FIG. 2 is an enlarged sectional view of the essential parts of FIG. 1, and FIG. 3 is a control rod of the present embodiment. FIG. 3 is a perspective view showing a main part of an output shaft. The damping force variable type hydraulic shock absorber includes a shock absorber unit 10 and an actuator 12 that controls a variable operation of a damping force variable mechanism 20 that variably controls the damping force of the shock absorber unit 10.

The shock absorber section 10 includes a cylinder 13 filled with hydraulic fluid, a piston 16 defining the inside of the cylinder 13 into an upper liquid chamber 14 and a lower liquid chamber 15, and the piston 1.
6, a damping force generating mechanism 17 that generates a damping force when the piston 16 moves up and down in the cylinder 13, and a piston rod that extends outside the cylinder 13 by supporting the piston 16 via a support shaft 18. 19, a damping force variable mechanism 20 that adjusts the area of the passage that connects the upper and lower liquid chambers 14 and 15 by rotation via a damping force generation mechanism 17 provided in the piston rod 19, and a cylinder 13 are housed. And an outer cylinder 21 that

The damping force varying mechanism 20 includes a piston rod 1
9 and a bypass passage 22 that is provided in the support shaft 18 connected thereto and that communicates between the upper and lower liquid chambers 14 and 15 separately from the damping force generating mechanism 17, and two bypass passages that face the outer circumference of the piston rod 19. The bypass passage 22 is provided with a lateral hole 23 that communicates with the upper liquid chamber 14, and a tubular adjuster 24 that is rotatably mounted in the bypass passage 22 and closes the lateral hole 23. The lower end of the bypass passage 22 is open to the lower liquid chamber 15. The adjuster 24 rotates to adjust the opening area of the bypass passage 22 to the upper liquid chamber 14, and the control rod 25 provided in the piston rod 19 penetrates in the axial direction thereof. It is connected.

The actuator 12 is the piston rod 1
It is attached to the upper part of 9 and has an output shaft 26. The output shaft 26 and the upper end of the control rod 25 are shown in FIG.
Are linked as shown in detail in. That is, the tip end portion of the control rod 25 is formed to have a smaller diameter 25a than the output shaft 26, and the small diameter portion 25a is formed with a two-face width portion 27. Further, the tip of the output shaft 26 has the small diameter portion 25.
A fitting hole 29 into which a is fitted is formed, and further, the fitting hole 2
The slit 2 into which the width across flats 27 is fitted at a position deeper than 9
8 are formed. By fitting the two-face width portion 27 into the slit 28, the output shaft 26 transmits the rotational torque of the actuator to the control rod 25 to rotate the adjuster 24.

The output shaft 26 and the control rod 25 are centered by fitting the small diameter portion 25a of the control rod 25 into the fitting hole 29.

Next, with reference to FIG. 3, the dimensional relationship among the width across flats 27, the slit 28 and the fitting hole 29 will be described.
That is, when the total length in the axial direction of the slit 28 is A, the length of the portion where the fitting hole 29 is not formed is B, and the total length in the axial direction of the flat width portion 27 is C,
There is a relation of A>B> C, and when the diameter of the fitting hole 29 is D and the diameter of the small diameter portion 25a of the control rod 25 is d, there is a relation of D> d. As a result, the small width portion 25a of the control rod 25 can be fitted into the fitting hole 29 at the same time when the double width portion 27 is fitted into the slit 28, and the centering between the output shaft 26 and the control rod 25 can be performed. To do.

Thus, according to this embodiment, the slit 2
By fitting the width across flats portion 27 into 8, the output shaft 26 and the control rod 25 rotate integrally, the rotational torque of the actuator 12 is transmitted to the control rod 25, and the adjuster 24 is rotated. The variable function of the damping force variable mechanism 20 is performed. Then, the output shaft 26 and the control rod 25 are fitted in the fitting hole 29 with the control rod 2
By fitting the small-diameter portion 25a of No. 5, the rotation shaft is configured and centered without using a separate part as in the prior art, and the slit 28 of the output shaft 26 and the flat width portion 27 of the control rod 25 rotate. The fulcrum for transmitting torque does not deviate from the axis, and as a result, the rotational load on the actuator 12 is reduced and the durability of the actuator 12 is improved.

In the above embodiment, the tip side of the control rod 25 is the small diameter portion 25a, and the small diameter portion 25a
Is fitted in the fitting hole 29 on the output shaft 26 side, and the small diameter portion 25
The slit 2 on the output shaft 26 side is formed in the width across flats 27 formed in a.
However, the present invention is not limited to this, and the small diameter portion 25d and the double width portion 27 may be provided on the output shaft 26 side, and the fitting hole 29 and the slit 28 may be formed on the control rod side. .

[0021]

In the rotating shaft connecting structure according to the above-described structure, one end of the output shaft and the control rod is formed to have a smaller diameter than the other, and the two-width portion is formed in the small diameter portion. A fitting hole into which the small-diameter portion is fitted, and a slit deeper than the fitting hole and into which the two-face width portion engages are formed at the other end, and both rotary shafts are connected to the two-face width portion. And the slit are rotationally engaged with each other, and the small diameter part is connected with the fitting hole by selecting it so that the width across flat part is fitted to the slit part and the rotational force of the output shaft is attenuated via the control rod, for example. The output shaft can be centered with respect to the control rod by fitting the small diameter part of the control rod into the fitting hole while transmitting to the force variable mechanism. For Even without using a separate part, the fulcrum for transmitting the rotational torque of the slit of the rotary shaft and the width across flats of the control rod does not deviate from the axial center, and as a result, the rotational load on the actuator is reduced, In addition to improving the durability of the actuator, the number of parts is reduced, and the ease of assembly due to this can be achieved, which is extremely effective in practice.

[Brief description of drawings]

FIG. 1 is a partial vertical cross-sectional side view showing the overall configuration of a variable damping force type hydraulic shock absorber of the present embodiment.

FIG. 2 is an enlarged sectional view of a main part of FIG.

FIG. 3 is a perspective view showing essential parts of a control rod and an output shaft of this embodiment.

FIG. 4 is a vertical sectional side view showing a main part of a conventional damping force variable hydraulic shock absorber.

[Explanation of symbols]

 10 Shock Absorber 12 Actuator 13 Cylinder 14 Upper Liquid Chamber 15 Lower Liquid Chamber 16 Piston 17 Damping Force Generating Mechanism 19 Piston Rod 20 Damping Force Variable Mechanism 25 Control Rod 25a Small Diameter 26 Output Shaft (Rotation Shaft) 27 Diagonal Width 28 Slit 29 Mating hole

Claims (1)

[Claims] 1. A rotary shaft connecting structure for connecting an output shaft for outputting rotation of an actuator and a control rod rotated by the output shaft, wherein a tip of one of the output shaft and the control rod has a smaller diameter than the other. And a flat width portion is formed on the small diameter portion, and a fitting hole into which the small diameter portion fits at the other end and the flat width portion is deeper than the fitting hole. And a slit formed therein, and both rotary shafts are rotatably engaged with the two-face width portion by the slit and are centered and connected with the small diameter portion by the fitting hole.