JPH0334507Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a surface wave motor for a hydraulic shock absorber, which is suitably used as an actuator for, for example, a damping force adjustable hydraulic shock absorber.

[Prior art]

For example, in a damping force adjustable hydraulic shock absorber, an actuator is attached to the upper end of the piston rod in order to adjust the damping force by rotating the adjusting rod inserted into the piston rod.

However, in the prior art, as this type of actuator, a rotary actuator with a damping mechanism attached to the motor or a reciprocating actuator with a rack and pinion mechanism driven by a solenoid is used, so the size of the actuator itself becomes large. , the weight has increased significantly.

[Problem to be solved by the invention] For this reason, in the conventional technology, it is necessary to provide a large space in advance in order to install the actuator on the upper end side of the piston rod. The disadvantage is that it is difficult to install. Furthermore, when a speed reduction mechanism is used, there is a drawback that mechanical noise is generated during operation.
Furthermore, there is a drawback that it is difficult to accurately position the adjustment rod when rotating and stopping the adjustment rod.

The present invention was developed in view of the above-mentioned drawbacks of the prior art. For example, when used as an actuator for a hydraulic shock absorber with adjustable damping force, the present invention can be made small and lightweight, and the installation space at the tip of the piston rod can be reduced. It is an object of the present invention to provide a surface wave motor for a hydraulic shock absorber that can eliminate noise generation and perform accurate positioning.

[Means for solving the problems] The configuration adopted by the present invention in order to solve the above-mentioned problems includes a cylindrical casing with a bottom, a cylindrical casing disposed inside the casing, and a high-frequency voltage applied from the outside. an annular ultrasonic transducer that generates vibrations; an annular elastic body that is disposed within the casing with one surface fixed to the ultrasonic transducer and generates surface waves on the other surface; a rotor rotatably disposed within the casing so as to be in pressure contact with the other surface of the body and rotationally driven by surface waves of the elastic body, and a hydraulic shock absorber is attached to the rotor. In a surface wave motor for a hydraulic shock absorber that fixes an adjustment rod, the casing has a convex portion protruding into the casing at the center of the bottom thereof, and a mounting hole to which the tip of the piston rod of the hydraulic shock absorber can be attached. and the annular ultrasonic transducer and the elastic body are arranged so as to surround the convex portion.

[Effect]

With this configuration, a convex part is protruded into the casing at the center of the bottom of the casing, and the piston rod tip of the hydraulic shock absorber is attached to the mounting hole provided in the convex part, and the annular ultrasonic vibrator and elastic Since the body is located inside the casing and is arranged to surround the convex part, the annular ultrasonic vibrator, elastic body, etc. are placed at approximately the same height as the tip of the piston rod installed in the mounting hole. This allows the axial dimension of the entire surface wave motor to be shortened.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 5.

1 to 3 show a first embodiment of the present invention.

In the figure, reference numeral 1 indicates a piston rod of a damping force adjustable hydraulic shock absorber. The tip of the piston rod 1 protrudes from a cylinder (not shown), and the protruding end has a large diameter portion 1A and a shaft extending from the large diameter portion 1A. A small diameter portion 1B extending in the direction, a threaded portion 1C located above the small diameter portion 1B, and a fitting portion 1D located above the threaded portion 1C and chamfered on both sides are provided. There is. An insertion hole 1E is formed in the axial direction of the piston rod 1, into which an adjustment rod 2, which will be described later, is inserted. Reference numeral 2 designates an adjustment rod rotatably inserted into the insertion hole 1E.The upper end of the adjustment rod 2 protrudes in the axial direction from the tip of the piston rod 1, and a double-sided chamfered portion 2A is provided at the upper end. A male thread 2B is formed on the outer peripheral surface of the double-sided chamfered portion 2A, into which a nut 13 (described later) is screwed (see FIG. 3). The lower end of the adjustment rod 2 is connected to a damping force adjustment shutter (not shown) provided within the cylinder.

Reference numeral 3 indicates a mounting mount for mounting the protruding end of the piston rod 1 to the body of the vehicle, and the mounting mount 3 is provided between the vehicle body side mounting member 3A, the shock absorber side mounting member 3B, and the mounting members 3A and 3B. A mounting hole 4 into which the small diameter portion 1B of the piston rod 1 is inserted is bored in the center of the shock absorber side mounting member 3B. 5 is provided. The small diameter portion 1B of the piston rod 1 is fitted into the mounting hole 4 of the mounting mount 3, and the protruding end of the piston rod 1 is tightened to the mounting mount 3 by screwing the nut 5 into the threaded portion 1C. It is starting to be worn.

Next, 6 shows the casing of the motor on the surface;
The casing 6 is formed into a cylindrical and flat shape with a bottom, and a thick convex portion 6A that protrudes upward in the axial direction into the casing 6 is provided at the center of the bottom.
A recess 6B is formed on the lower surface side. In the center of the convex portion 6A, the fitting portion 1 is chamfered on both sides.
A fitting hole 6C as a mounting hole having a shape corresponding to D is bored, and the fitting hole 6C is press-fitted into the fitting part 1D, so that the recess 6B covers the upper surface side of the nut 5. ing. Further, an inner flange 7 extending radially inward is provided at the upper end of the casing 6.
An annular projection 7A that slightly projects downward in the axial direction is bored at the inner peripheral end of the inner flange 7, and a nut 13, which will be described later, is fastened to the radially inner side of the projection 7A. An annular space 8 is formed for this purpose.

Reference numeral 9 denotes a piezoelectric body as an ultrasonic vibrator, which is positioned so as to surround the convex portion 6A of the casing 6 and is fixed on the bottom of the casing 6. The piezoelectric body 9 is made of barium titanate or the like. It is formed into a thin ring shape from a piezoelectric material. The piezoelectric body 9 is designed to generate ultrasonic vibrations when a high frequency voltage is applied from the outside. Reference numeral 10 denotes an elastic body whose lower surface is fixed onto the piezoelectric body 9 by means of adhesive or the like, and the elastic body 10 is made of a material such as brass or aluminum and is formed into an annular shape so as to surround the periphery of the convex portion 6A. A large number of trapezoidal or rectangular protrusions 10A, 10A, . . . are provided on the upper surface thereof at predetermined intervals in the circumferential direction (see FIG. 2).
The elastic body 10 resonates with the vibration of the piezoelectric body 9 and generates surface waves on the surface of each protrusion 10A.

11 is a rubber ring placed on the surface of each protrusion 10A, 12 is a rotor that constitutes a rotor together with the rubber ring 11, and the rotor 12 is formed into a disk shape of a spring material. A fitting hole 1 shaped for the double-sided chamfered portion 2A of the adjustment rod 2 is provided in the center.
2A is drilled (see Figure 3). here,
The rotor 12 is fitted into the double-sided chamfered portion 2A through the fitting hole 12A, and the outer peripheral side thereof is fitted with the rubber ring 1.
It is rotatably disposed within the casing 6 so as to be located on the upper surface side of the elastic body 10 via the elastic body 1 . The rotor 12 is fitted with a nut 13 screwed onto the external thread 2B of the adjustment rod 2 through the annular space 8.
It is elastically deformed so as to bend slightly downward in the axial direction, and its outer peripheral side is pressed against the surface of each protrusion 10A of the elastic body 10 via a rubber ring 11 with a constant load. Further, the projection 7A of the inner flange 7 abuts against the upper surface of the rotor 12 from above with a weak force.

Thus, the surface waves of the elastic body 10 are transmitted to the rotor 12 via the rubber ring 11, whereby the rotor 12 is rotationally driven together with the rubber ring 11, causing the adjustment rod 2 to rotate. ing. In this case, by changing the direction of conduction of the high frequency voltage to the piezoelectric body 9, the rotor 12 can be rotated forward or backward as appropriate. In addition,
The rubber ring 11 is made of a resin material with high wear resistance and is formed into a thin ring shape. Depending on the case, the rubber ring 11 may be bonded to the lower surface of the outer peripheral side of the rotor 12.

Next, the operation of the surface wave motor for a hydraulic shock absorber configured as described above will be explained.

First, when adjusting the damping force of the hydraulic shock absorber, if a high frequency voltage is applied to the piezoelectric body 9 from the outside,
The piezoelectric body 9 generates ultrasonic vibrations, thereby generating surface waves on the surface of each protrusion 10A of the elastic body 10. Since the rotor 12 is pressed against the surface of each protrusion 10A with a constant load through the rubber ring 11, the rotor 12 and the rubber ring 11 are rotationally driven by the surface waves of the elastic body 10, and the The adjustment rod 2 is rotated together with the rotor 12 to adjust the damping force. In this case, the rotational directions of the rotor 12 and adjustment rod 2 are changed as appropriate depending on the direction of conduction of the high-frequency voltage, making it possible to adjust the damping force as desired.

Thus, according to this embodiment, the piezoelectric body 9, the elastic body 10, the rotor 12, etc. are built in the flat cylindrical casing 6, and by applying a high frequency voltage to the piezoelectric body 9, the rotor 12 is Since the damping force can be adjusted by appropriately rotating the adjustment rod 2 via the It is possible to reduce the size and weight by reducing the size and weight. Furthermore, it is possible to easily incorporate the actuator into a vehicle with a small space for mounting the actuator, and it is also possible to lower the height of the vehicle. Furthermore, since a speed reduction mechanism or the like is not required, it is possible to eliminate the occurrence of mechanical noise. Furthermore, by turning on and off the high frequency voltage applied to the piezoelectric body 9, the ultrasonic vibration of the piezoelectric body 9 can be immediately excited or stopped.
The adjusting rod 2 can be immediately stopped at a desired rotational position via the rotor 12, and deviations in the rotational position can be eliminated.

In addition, according to this embodiment, a convex portion 6A is provided at the center of the bottom of the casing 6, and the casing 6 is attached to the tip of the piston rod 1 through the fitting hole 6C formed in the convex portion 6A. Since the piezoelectric body 9 and the elastic body 10 are disposed so as to surround the convex portion 6A, the piezoelectric body 9 and the elastic body 10 are connected to the piston rod 1.
It can be placed at almost the same height as the tip of the rod, making it possible to further reduce the overall axial dimension.
The space for mounting the actuator can be further reduced. In addition, since the rotor 12 itself has spring properties, a constant load can be applied to the rotor 9 without using a separate spring, and an axial space for arranging this spring can be eliminated.
It becomes possible to further reduce the axial dimension of the casing 6.

FIGS. 4 and 5 show a second embodiment of the present invention, and the features of this embodiment include an outer case hinged to the tip of the piston rod, and a removable structure for attaching the casing of the surface wave motor to the outer case. The motor is configured with an inner case that can be fitted into the inner case, and each component of the surface wave motor is housed within the inner case. In this embodiment, the same components as those in the first embodiment shown in FIGS. 1 and 2 are given the same reference numerals, and their explanations will be omitted.

In the figure, 21 indicates a piston rod of a hydraulic shock absorber, and the piston rod 21 is formed almost the same as the piston rod 1 used in the first embodiment, with a large diameter portion 21A, a small diameter portion 21B, and a threaded portion 2.
It starts from 1C. An insertion hole 21D is formed in the axial direction of the piston rod 21, and an adjustment rod 22 is rotatably inserted into the insertion hole 21D. Here, the adjustment rod 22 is
The adjusting rod 2 is formed shorter than the adjusting rod 2 used in the embodiment described above, and a double-sided chamfered portion 22A is formed at the upper end of the adjustment rod 2 so as to be positioned within the insertion hole 21D. In addition, the small diameter portion 21A of the piston rod 21 is attached to the mounting mount 3.
The piston rod 21 is fastened to the mounting mount 3 by screwing the nut 5 into the threaded portion 21C.
Then, the shock absorber side mounting member 3 of the mounting mount 3
B has an outer case 24, which will be described later, located on the upper side.
A large diameter groove 23 capable of accommodating the nut 5 is formed.

Reference numeral 24 denotes an outer case that constitutes the casing of the surface wave motor together with an inner case 26, which will be described later. has a convex portion 2 extending in the axial direction toward the inside of the outer case 24.
4A is provided protrudingly. A threaded hole 24B serving as a mounting hole is bored in the center of the convex portion 24A in the axial direction, and the outer case 24 is screwed onto the threaded portion 21C of the piston rod 21 through this threaded hole 24B. Further, an annular projection 24C is provided at the open end of the outer case 24 to protrude radially inward to prevent the inner case 26 from being removed, which will be described later. Here, the annular projection 24C is connected to the outer case 24.
Notches 24D, 24 extending to the axially intermediate portion of
A downwardly inclined guide surface 24E is formed on the upper surface side of the annular projection 24C. When the inner case 26 is fitted into the outer case 24, the outer periphery of the lower surface of the inner case 26 is guided by the guide surface 24E, and the annular protrusion 24C
is easily enlarged in diameter by each notch 24D, so that the inner case 26 can be easily fitted into the outer case 24.

Further, a lock nut 25 is located on the upper surface side of the convex portion 24A and is screwed onto the threaded portion 21C of the piston rod 21. The lock nut 25 is connected to the convex portion 2 of the outer case 24 between
4A prevents the screw hole 24B of the convex portion 24A from loosening relative to the threaded portion 21C. Note that the lock nut 25 is connected to the convex portion 24.
It may be fixed in advance to the upper surface of A by adhesive or other means.

Reference numeral 26 denotes an inner case that is formed into a flat cylindrical shape so as to be fitable inside the outer case 24, and has both ends in the axial direction closed.The inner case 26 has a convex portion 24A of the outer case 24 and a lock nut 25 at the center of the bottom. A fittable recess 26A is provided upward in the axial direction, and a protrusion 26B that can be engaged with a disc spring 26, which will be described later, protrudes from the center of the upper part. A piezoelectric body 9 and an elastic body 10 are disposed in the inner case 26 so as to surround the recess 26A (projection 24A), and a rubber ring is attached to the surface of each protrusion 10A of the elastic body 10. 11 is placed. 27 is a rotor that constitutes a rotor together with the rubber ring 11;
The rotor 27 is formed into a disk shape, and the outer peripheral side of the rotor 27 is connected to each protrusion 1 of the elastic body 10 by a disc spring 29 (described later).
It is pressed against the surface of 0A via a rubber ring 11 with a constant load.

Reference numeral 28 denotes an output shaft that projects downward in the axial direction from the center of the rotor 27 and rotates integrally with the rotor 27. The output shaft 28 passes through the center of the upper side of the recess 26A and extends through the insertion hole 21D. It protrudes inward. A slotted groove 28A is provided at the lower end of the output shaft 28, and the slotted groove 28A engages with the double-sided chamfered portion 22A of the adjustment rod 22. It is designed to rotate as one with the. Furthermore, 29 is a disc spring for applying the constant load to the rotor 27, and the inner peripheral end of the disc spring 29 is connected to the protrusion 26B of the inner case 26.
The outer peripheral end side thereof is pressed against the upper surface of the outer peripheral side of the rotor 29 with a predetermined spring load.

In this embodiment configured in this way, the rotor 2
Since the outer peripheral side of the piezoelectric body 7 is pressed against the surface of each protrusion 10A of the elastic body 10 with a constant load by the disc spring 29, a high frequency voltage is applied to the piezoelectric body 9, and the elastic body 1
By generating surface waves on the surface of each protrusion 10A of 0, the rotor 27 can be rotationally driven, and the output shaft 28
The damping force can be adjusted by appropriately rotating the adjustment rod 22 via the .

Therefore, in this embodiment as well, substantially the same effects as in the first embodiment can be obtained. In particular, in this embodiment, the inner case 26 containing the piezoelectric body 9, the elastic body 10, the rotor 27, etc. the outer case 2
4, the outer case 24 is attached to the threaded portion 21C of the piston rod 21.
After screwing into the surface wave motor and preventing loosening with the lock nut 25, the inner case 26 can be easily fitted into the outer case 24, and the surface wave motor can be easily and reliably mounted. be able to.

In each of the above embodiments, a large number of protrusions 10A are provided on the upper surface of the elastic body 10, but the protrusions 10A are omitted and a rubber ring 11 is provided on the upper surface of the elastic body 10. etc. may be placed directly. In addition, a piezoelectric material 9 is used as an ultrasonic transducer.
was used, but instead of this, a magnetostrictive vibrator or the like may be used.

Furthermore, in the second embodiment, the outer case 2
4 to the tip of the piston rod 21,
Although the inner case 26 is fitted into the outer case 24, instead of this, the inner case 26 is fitted into the outer case 24 in advance, and then the outer case 24 is fitted together with the lock nut 25 by the screw of the piston rod 21. It may be attached by screwing onto the portion 21C. In addition, the rotor 27 is
However, instead of the disc spring 29, a conical coil spring, a normal coil spring, etc.
Various springs may be employed.

[Effect of idea]

As detailed above, according to the present invention, in order to attach the casing of the surface wave motor to the tip of the piston rod of the hydraulic shock absorber, a convex portion is provided at the center of the bottom of the casing, and the tip of the piston rod is attached to the convex portion. Since a mounting hole is provided and the annular ultrasonic vibrator and elastic body are placed so as to surround the protrusion, the ultrasonic vibrator and elastic body can be placed at almost the same height as the tip of the piston rod. It is possible to shorten the overall axial dimension. Therefore, when the surface wave motor is used as an actuator for adjusting damping force, the space for mounting the actuator can be reduced, and the vehicle height can be lowered. Furthermore, generation of noise and displacement of rotational position can be reliably prevented.

[Brief explanation of the drawing]

1 to 3 show a first embodiment of the present invention, FIG. 1 is a vertical cross-sectional view showing the surface wave motor attached to a hydraulic shock absorber, and FIG. 2 is a piezoelectric shock absorber shown in FIG. 1. FIG. 3 is a perspective view showing the piston rod, adjustment rod, and rotor in FIG. 1 before they are assembled; FIGS. A second embodiment of the invention is shown, and FIG. 4 is a longitudinal cross-sectional view showing the surface wave motor attached to a hydraulic shock absorber, and FIG. 5 is a partially cutaway view showing the outer case and inner case in FIG. 4. FIG. 1, 21...Piston rod, 2, 22...Adjustment rod, 6...Casing, 6A...Protrusion, 9
... Piezoelectric body, 10 ... Elastic body, 11 ... Rubber ring, 12, 27 ... Rotor (rotor), 24 ...
Outer case, 24A... Convex portion, 25... Lock nut, 26... Inner case, 26A... Concave portion, 2
8... Output shaft, 29... Belleville spring.

Claims (1)

[Scope of utility model registration request] A cylindrical casing with a bottom, an annular ultrasonic vibrator disposed inside the casing that generates vibration by applying a high frequency voltage from the outside, and a ring-shaped ultrasonic vibrator that is fixed to the ultrasonic vibrator on one side and inside the casing. an annular elastic body disposed in the casing and generating a surface wave on the other surface; and an annular elastic body rotatably disposed within the casing so as to be in pressure contact with the other surface of the elastic body In a surface wave motor for a hydraulic shock absorber, the surface wave motor for a hydraulic shock absorber is provided with a rotor rotationally driven by a surface wave of the motor, and an adjustment rod of a hydraulic shock absorber is fixed to the rotor. A mounting hole is provided in the convex part to which a piston rod tip of a hydraulic shock absorber can be attached, and the annular ultrasonic vibrator and the elastic body are arranged to surround the convex part. A surface wave motor for a hydraulic shock absorber.