JP2526601Y2 - Variable damping force type hydraulic shock absorber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an actuator, particularly an actuator used for a variable damping force type hydraulic shock absorber.

2. Description of the Related Art There is known a so-called variable damping force type hydraulic shock absorber which is used for a suspension device of an automobile and can adjust a damping force of a hydraulic shock absorber according to a running state of a vehicle.
This type of variable damping force type hydraulic shock absorber includes a damping force generating mechanism for generating a damping force, and a damping force variable mechanism for bypassing a part of the hydraulic fluid passing through the damping force generating mechanism between the respective liquid chambers. ing.

In this damping force variable mechanism, a bypass passage is formed in a piston rod to which a piston is fixed, and an adjuster having a plurality of orifices having different diameters is accommodated in the bypass passage. Then, this adjuster is rotated by the actuator via the control rod,
By selecting one of the orifices having different diameters, the bypass amount of the hydraulic fluid flowing through the bypass passage is adjusted, and for example, each of the soft, medium, and hard damping force modes is selected.

As an actuator for rotating such an adjuster, for example, an actuator described in JP-A-63-114555 is known.

In this device, an output shaft for transmitting rotation to a damping force variable adjuster, and a rotor having a hole in the center and a permanent magnet fixed on the outer periphery are loosely fitted, and a pin mounted on the output shaft is provided. Is engaged with an axial groove formed in the rotor, thereby restricting only relative movement with respect to the rotor in the circumferential direction, and has a so-called floating structure that allows movement in the axial direction. Then, by selectively exciting the plurality of electromagnets, the permanent magnet fixed to the rotor is attracted, the output shaft is rotated, and thus the adjuster is rotated with respect to the bypass passage.

[Problem to be Solved by the Invention] However, the above-described actuator has a floating structure in which the relative movement of the output shaft in the circumferential direction is restricted, but the relative movement is allowed in the axial direction. As a result, a vibration occurs on the output shaft on which the pins are implanted due to vibrations or the like during the running of the vehicle. As a result, there is a problem that abnormal noise is generated due to the contact of the pin with the bottom surface of the axial groove or the like, which causes discomfort to the occupant.

SUMMARY OF THE INVENTION An object of the present invention is to provide an actuator which can solve the problems of the conventional device and can prevent the generation of abnormal noise while taking advantage of the floating structure.

Means for Solving the Problems According to the present invention, in order to achieve the above object, a damping force generating mechanism for generating a damping force and a part of the hydraulic fluid passing through the damping force generating mechanism are bypassed between the liquid chambers. A variable damping force mechanism for varying the damping force, wherein the variable damping force mechanism rotates an adjuster having a plurality of orifices formed in the bypass passage via a control rod. In the damping force variable type hydraulic shock absorber provided with an actuator for adjusting a bypass amount of the hydraulic fluid flowing through the bypass passage by selecting any one of the plurality of orifices, the actuator includes:
A casing, a stator having a plurality of electromagnets arranged at a predetermined distance in a circumferential direction in the casing, and a permanent magnet fixed to an outer peripheral portion having a hole at a central portion rotatably supported by the casing and having a central portion. A rotor member, an output shaft which is loosely fitted in a hole of the rotor member and transmits rotation to the damping force adjuster, and restricts circumferential relative movement between the output shaft and the rotor member, And an elastic member interposed between the inner periphery of the hole of the rotor member and the outer periphery of the output shaft.

According to the present invention, the outer periphery of the output shaft, which is loosely fitted in the hole of the rotor member, restricts the relative movement of the rotor member in the circumferential direction, and transmits the rotation to the damping force adjuster, and the rotor member. An elastic member is interposed between the hole and the inner periphery of the hole. When the rotor member rotates, the output shaft also rotates because the relative movement is restricted, and the rotation is transmitted to the adjuster.

Further, even if an excessive force such as twisting is input from the output shaft, the force is not transmitted to the rotor member because of the floating structure.

And, even if the output shaft fluctuates due to vibrations during traveling of the vehicle, this movement is controlled by the elastic member,
Since there is no collision with other parts, generation of abnormal noise is prevented.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 to 3, reference numeral 1 denotes a variable damping force type hydraulic shock absorber which includes a cylinder 2 filled with hydraulic fluid, a piston 5 defining the interior of the cylinder 2 as two fluid chambers 3 and 4, A damping force generating mechanism 6 provided on the piston 5 to generate a damping force when the piston 5 moves in the cylinder 2; and a piston rod 7 having the piston 5 attached to one end.
And a damping force generating mechanism 6 provided on the piston rod 7.
And a variable damping force mechanism 8 that adjusts the bypass amount of the hydraulic fluid that is replaced and circulated between the two liquid chambers 3 and 4 via the control valve.

The damping force generating mechanism 6 includes a plurality of passages 6 formed in the piston 5 so as to be spaced apart from each other in the circumferential direction and penetrate vertically.
a, 6f, a compression-side valve element 6e disposed on the upper surface of the piston 5 to cover the plurality of passages 6f in the extension stroke and open in the compression stroke.
A slit 6b provided on the upper surface of the piston 5 below the pressure-side valve element 6e and constantly communicating the plurality of passages 6a with the liquid chamber 3, and a slit 6b disposed on the lower surface of the piston 5 to cover the plurality of passages 6a in a pressure stroke. And the piston 5 that opens during the extension stroke and the piston 5
A plurality of passages 6f provided on the extension side valve body 6d on the lower surface of
Is provided with a slit 6c which constantly communicates the hydraulic fluid between the liquid chambers 3 and 4 as the piston 5 moves in the cylinder 2 during the extension stroke and the pressure stroke. A damping force is generated.

The damping force variable mechanism 8 is formed in the piston rod 7 to bypass the damping force generating mechanism 6 to communicate the two liquid chambers 3 and 4 with each other. And the adjusted adjuster 10. This adjustment lake 10
An actuator 12 is connected to the piston rod 7 via a control rod 11 which is inserted through the center of the shaft of the piston rod 7. One of a plurality of orifices 10a having different diameters provided on the adjuster 11 by the actuator 12 is provided. By selectively communicating the orifice 10a with a communication hole 13 provided in the peripheral wall of the bypass passage 9 of the piston rod 7, the adjuster 10 adjusts the bypass amount of the hydraulic fluid flowing through the bypass passage 9.

The upper end of the piston rod 7 that sealingly penetrates the cylinder 2 is attached to the upper mount insulator 15. Then, a nut 16 is fastened to a threaded portion of the piston rod 7 that penetrates through the upper mount insulator 15 and protrudes upward from the upper mount insulator 15,
It is attached to the vehicle body in a known manner.

Here, the actuator 12 includes a casing 20, an output shaft 21, a rotor 22, and a stator 23, as shown in FIGS. The casing 20 includes an upper casing 20A and a lower casing 20B, and is airtightly connected by ultrasonic welding or the like. As shown in FIG. 1, a plurality of flanges 27 extend horizontally outward in the radial direction on the outer peripheral edge of the lower surface of the lower casing 20B. These flanges 27
Is fixed to an actuator bracket 28 provided on the upper mount insulator 15 with a bolt 29.

The upper casing 20A has a plurality of stator cores 31A.
Is fixed, and stator plates 33 and 34 are integrally molded with the lower casing 20B. The plurality of stator cores 31A have bobbins 3
A solenoid 31C wound around 1B is fitted to form the electromagnet 31, and a mount base 35 serving as a wiring board is fixed between the plurality of stator cores 31A and the bobbin 31B.

The stator 23 has six electromagnets 31 arranged at equal intervals in the circumferential direction, and is supplied with power by a wiring 37 passing through a grommet 36 fitted in the casing 20. The rotor 22
Collar 40 at center and boss integrally molded
41, and two fan-shaped flat permanent magnets 42 fixed to the boss 41 at a distance of 180 °.

Both ends of the collar 40 are rotatably supported by a bearing 43 fixed to the upper casing 20A together with the stator plate 32, and a bearing 44 fixed to the lower casing 20B together with the stator plate 33. The boss 41 and the permanent magnet 42 rotate integrally. Both the collar 40 and the boss 41 are formed with axial grooves or notches 40A and 41A at the upper end thereof, and the pins 21A implanted in the output shaft 21 engage with the pins 21A and 41A.
Restricts the relative movement of the rotor 22 and the output shaft 21 in the circumferential direction, but allows the relative movement in the axial direction, and even if there is an unreasonable input such as twisting on the output shaft 21, This constitutes a locking means for the output shaft 21 so as not to be present.

Further, an annular groove 21B is formed in the middle part of the output shaft 21, and an elastic member 45 such as an O-ring or a D-ring is fitted in the annular groove 21B. The outer peripheral portion of the elastic member 45 elastically contacts the inner peripheral portion of the collar 40.

It is to be noted that an engagement groove 21C with which the tip of the control rod 11 is engaged is formed at a lower end portion of the output shaft 21, and a seal 46 for ensuring sealing with the piston rod 7 is provided on the lower casing 20B and the lower casing 20B. Is provided.

In this embodiment having the above configuration, as is well known, the excitation positions of the electromagnets 31 facing each other are switched according to the operation of a changeover switch such as hardware, software, or medium.
Then, correspondingly, the attraction force or repulsion force acting on the permanent magnet 42 rotates the rotor 22 and stably stops at the position where the magnetic flux density is highest. The rotation of the rotor 22 is transmitted to the output shaft 21 via the pin 21B, and further transmitted to the adjuster 10 via the control rod 11. Then, the orifices having different diameters are switched and controlled.

When the output shaft 21 rotates, the annular groove of the output shaft 21
The elastic member 45 fitted to the 21B does not cause any trouble since it rotates integrally with the collar 40.

Then, even if the output shaft 21 having a floating structure attempts to move in the vertical direction due to vibration during traveling of the vehicle, the elastic member 45 elastically contacts the collar 40, and the output shaft 21 is elastically supported. Is blocked.

Also, any attempt to move the output shaft 21 in a direction perpendicular to the shaft within the loosely fitted collar 40 is similarly prevented.

Therefore, it does not come into contact with other parts and generation of abnormal noise is suppressed.

[Effects of the Invention] As is apparent from the above description, according to the present invention, since the elastic member is interposed between the inner periphery of the hole of the rotor member and the outer periphery of the output shaft, any floating function is provided. It is possible to obtain an actuator capable of preventing generation of abnormal noise during running of the vehicle without hindrance.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is a sectional view taken along line III-III of FIG. 10 ... Adjuster, 20 ... Casing, 21 ... Output shaft, 21A ... Pin, 22 ... Rotor, 31 ... Electromagnet, 40 ... Collar, 40A ... Axial groove (notch), 41 ... Boss part, 41A ... Axial groove (Notch), 42: permanent magnet, 45: elastic member.

Claims (1)

(57) [Scope of request for utility model registration] A damping force generating mechanism for generating a damping force, and a damping force variable mechanism for changing a portion of the hydraulic fluid passing through the damping force generating mechanism between the liquid chambers to make the damping force variable. In the damping force variable mechanism, an adjuster having a plurality of orifices formed in the bypass passage is rotated via a control rod to select any one of the plurality of orifices. In the variable damping force type hydraulic shock absorber provided with an actuator for adjusting a bypass amount of the working fluid flowing through the bypass passage, the actuator is separated from the casing by a predetermined distance in a circumferential direction in the casing. A stator having a plurality of electromagnets arranged therein, and a rotor rotatably supported by the casing and having a hole in the center and having a permanent magnet fixed to the outer periphery And wood, an output shaft this is loosely fitted into a hole of the rotor member transmits rotation to the coordinator for the damping force variable,
Locking means for restraining relative movement of the output shaft and the rotor member in the circumferential direction and permitting movement in the axial direction; and interposing between the inner periphery of the hole of the rotor member and the outer periphery of the output shaft. And a variable damping force type hydraulic shock absorber.