JPH0424201Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a rotary actuator suitable for use as a drive device for driving an adjustment mechanism for adjusting the damping force of a hydraulic shock absorber.

[Problems to be Solved by the Invention] When adjusting the damping force of a hydraulic shock absorber installed in a vehicle according to driving conditions and road conditions, a damping force adjustment mechanism is provided in the hydraulic shock absorber. This damping force adjustment mechanism is provided with a drive device that rotates an adjustment member that adjusts the opening degree of the oil passage, and up to now, a rotary solenoid or a geared motor has been used as this drive device. On the other hand, recently, the number of damping force adjustment stages has tended to improve from the conventional two stages to three stages, and this drive device is also required to have three or more stopping positions. It's coming. However, with the rotary solenoid mentioned above, it is difficult to have three or more stopping positions due to its mechanism, and in the case of geared motors, the common method is to detect the position with an encoder, but the control circuit is complicated. It is not something that can fully respond to the purpose of becoming a new company. In contrast, a rotary actuator with three stop positions that can be driven by a simple control circuit has been proposed.

However, in the rotary actuator described above, after the worm wheel and pin wheel that make up the actuator stop at a predetermined position, only the worm wheel rotates further due to the inertia of the motor and hits one pin of the pin wheel. If the worm wheel stops in contact with the other pins, there will be a gap between the other pins and the worm wheel. After that, if the output shaft fixed to the pin wheel rotates for some reason, it rotates by the distance between the other pins and the worm wheel, and the positioning accuracy of the adjustment member deteriorates by that amount.

The present invention has been devised in view of the above points, and its purpose is to provide a rotary actuator that can perform accurate positioning with a simple control circuit and can reduce costs.

[Means for Solving the Problems] According to the present invention, the object is to provide a first rotating body that is rotatably provided around a first rotating shaft;
A plurality of first rotors are provided on one surface of the first rotating body and arranged at equal intervals in the circumferential direction of the first rotating shaft.
a second rotating body rotatably provided around a second rotating shaft eccentric to the first rotating shaft; and one of the first rotating bodies of the second rotating body. radially after rotating the first rotating body by a certain rotation angle by contacting one of the first protrusions of the first rotating body at a predetermined position and rotating the first rotating body by a certain rotation angle. The contact is removed, and the first protrusion 1
and another first protrusion adjacent thereto, the second protrusion having a circumferential surface formed in an arc shape around the second rotation axis; This is accomplished by a rotary actuator having a motor coupled to the second rotating body to rotate the second rotating body about the axis.

[Specific Example] Next, the present invention will be described in further detail based on a preferred specific example used as a drive device for a damping force adjustment mechanism of a hydraulic shock absorber as shown in the drawings.

In Figures 1 to 7b, Figures 9 and 10, an inner cylinder 1 as a cylinder is installed in an outer cylinder 2, and a cap 3 is fixed to one end of the inner cylinder 1 and the outer cylinder 2. A mounting ring 4 for mounting the hydraulic shock absorber 97 on a vehicle or the like is integrally connected to the cap 3. A rod guide 5 and a cap 6 are fitted into the other ends of the inner cylinder 1 and the outer cylinder 2, respectively, and a piston rod 7 passes through the guide 5 and the cap 6 and extends upward. A packing 8 is provided in the cap 6 so as to contact the periphery of the rod 7 in a sealing manner, and the packing 8 is pressed against the inner surface of the cap 6 and the outer peripheral surface of the rod 7 by a spring 10 via a retainer 9. ing.

A piston 11 fitted into the inner cylinder 1 is connected to one end of the rod 7 so as to define the chamber 12 of the inner cylinder 1 into two oil chambers 13 and 14. piston 1
1 includes one-way valves 15 and 16 made of disk valves.
Passages 17 and 18 are provided which are opened and closed, respectively. Furthermore, the piston 11 has a chamber 13,
A passage branching off from the passage 17, that is, a fixed orifice, is provided to keep the passage 14 in constant communication. 19 is a washer, and 20 is a piston ring.

The valve 15 opens when the hydraulic pressure in the chamber 14 becomes larger than a certain value with respect to the hydraulic pressure in the chamber 13, and allows the oil to flow from the chamber 14 to the chamber 13 through the passage 17. When the value becomes smaller than a certain value, the valve closes.
Oil fluid is prevented from flowing from chamber 14 to chamber 13 via passage 17. The valve 16 opens when the hydraulic pressure in the chamber 13 is higher than a certain value compared to the hydraulic pressure in the chamber 14, and closes when it is lower than the hydraulic pressure in the chamber 14.
and perform the opposite action.

An annular chamber 2 defined by an inner cylinder 1 and an outer cylinder 2
1 communicates with a chamber 14 through a through hole 22 bored at one end of the inner cylinder 1, and chambers 21, 13, and 14 contain oil, and an inert gas is placed above the chamber 21. Pressurized gas is enclosed.

The rod 7 is provided with a through hole 23 extending in the longitudinal direction from the upper end to the lower end of the rod 7.
A connecting rod 24 extends rotatably within the through hole 23 . The rod 7 also has a through hole 23 and a chamber 13.
A radial through hole 25 is provided to connect the two. Furthermore, a cylindrical body 26 is screwed onto the lower end of the rod 7, and a lid 27 is screwed onto the lower end of the cylindrical body 26. The through holes 23 and 25 constitute an oil passage.

A shutter 29 is attached to one end of the connecting rod 24 as an opening adjustment member that is rotatably held within the cylindrical body 26. On the side wall of the cylindrical body 26,
Holes 30, 31 and 32 of different diameters are bored, and the shutter 29 is connected to the cylinder body 2 through the connecting rod 24.
6, the holes 30, 31 and 32 as orifices are selectively opened and closed via the hole 34 of the shutter 29. The holes 30, 31, and 32 are each provided in the side wall of the cylinder 26 at angular intervals of about 120 degrees. The diameter of holes 30, 31, 32 is 32,3
The numbers decrease in the order of 1 and 30. Shyatsuta 29
The hole 34 extends through the side wall of the shutter 29 with a predetermined width, and this width is set to be smaller than the respective intervals between the holes 30, 31, and 32 and larger than the diameter of the hole 32. A spring 35 is disposed between the shutter 29 and the lid 27, and the spring 35 urges the shutter 29 upward. The shutter 29 has a hole 36 in addition to the hole 34.
is formed to have a sufficiently larger passage cross-sectional area than the hole 32, and the hole 23 and the holes 30, 31, 32 communicate with each other via the holes 34, 36. One end of the rod 7 located outside the inner cylinder 1 is attached to the vehicle body via an attachment mechanism 37. An O-ring 38 is arranged at the upper end of the hole 23 to prevent leakage of oil from the hole 23. A case 40 of a rotary actuator 39 serving as a driving device for rotating the connecting rod 24 and hence the shutter 29 is attached to the upper end of the rod 7, and a DC motor 51 is attached to the case 40. motor 51
A pinion 52 is fixed to the output shaft of the motor, and the pinion 52 meshes with a spur gear portion 53a of a gear 53, so that the rotation of the pinion 52 is transmitted to the gear 53. Further, the gear 53 has a worm gear portion 53b, and this worm gear portion 53b meshes with a worm wheel portion 54a of the gear 54. The rotation of the worm wheel portion 54a is controlled by the worm gear portion 54.
It is transmitted to the worm wheel 55 as the second rotating body through the rotation of b. A rotation mechanism connected to a worm wheel 55 is formed by a motor 51, a pinion 52, and gears 53 and 54. The worm wheel 55 can freely rotate around a cylindrical protrusion 62 provided on the housing 57 as a second rotating shaft, using the side surface as a sliding surface.
(see figure). A cylindrical eccentric hole 61 is provided in the cylindrical projection 62.
An output shaft 73 serving as a first rotating shaft provided on the pin wheel 56 located above the worm wheel 55 is fitted into the hole 61 . As shown in the drawing, a cylindrical projection 62 is the rotation axis of the worm wheel 55, and an output shaft 73 is the rotation axis of the pin wheel 56 as the first rotating body.
That's eccentric. On the surface of the pin wheel 56 facing the worm wheel 55, pins 60a, 60b, and 60c as first projections are provided to protrude at equal intervals on the same circumference, and as the worm wheel 55 rotates, the worm wheel 55 rotates. It is designed to come into contact with or separate from arcuate projections 58 and 59 as second projections of the wheel 55.

Referring to FIG. 6, on the top surface of the pin wheel 56,
A conductive plate 63 having a notch 63a in a part is provided. Opposed to this surface, the housing 57
From there, brushes 64, 65, 66, and 67 extend in a positional relationship as shown in the figure. Also, the conduction plate 63 and the brush 6
4, 65, and 66, when the arcuate protrusions 58, 59 of the worm wheel 55 and the pins 60a, 60b, 60c of the pin wheel 56 come out of contact, that is, when they are in the state shown in FIG. brush 6
4, 65, and 66 are positioned in the notch 63a of the conductive plate 63, that is, in the state shown in FIG. The brush 67 is always electrically connected to the conductive plate 63 and also connected to the motor 51. Also, the brushes 64, 65, and 66 are connected to the contact point 6.
9, 70 and 71, and the changeover switch 68
It is designed to be switched by. 72 is a battery. An output shaft 73 integrally formed with the pin wheel 56 is connected to the connecting rod 24, and rotation of the pin wheel 56 is caused by the engagement of the arcuate projections 58, 59 of the worm wheel 55 with the pinions 60a, 60b, 60c. When the output shaft 73 is rotated, the shutter 29 is also rotated in the same direction via the connecting rod 24. The switch 68 is attached to the operation panel of the driver's seat of the vehicle in which the hydraulic shock absorber 97 is installed.
A movable contact piece 75 of the switch 68 is connected to one terminal of a battery 72, and the other terminal of the battery 72 is connected to the other terminal of the motor 51.

In the hydraulic shock absorber 97 having the rotary actuator 39 configured in this way, the switch 68
As a result of the brush 64 and the brush 67 having the notch 63a connected to the contact 71 placed in the position shown in FIG. 52, gear 53, gear 54, worm wheel 55, pin wheel 56, connecting rod 24 and shutter 29 remain stopped, hole 34 coincides with hole 30, and chamber 1
3 and chamber 14 are holes 25, 23, 36, 34 and 3.
1, and the hydraulic shock absorber 97 applies a damping force defined by the fixed orifice formed in the piston 11, the valve 16, and the hole 30 when the piston 11 moves on the extension side, that is, in the G direction. arise.
Since the diameter of the hole 30 is smaller than that of the holes 32 and 31, the first hardest damping force is obtained in the hydraulic shock absorber 97 in this case. The same first hardest damping force is obtained also on the contraction side, that is, when the piston 11 moves in the H direction. Next, when the switch 68 is operated to contact the contact 70, the current of the battery 72 flows through the conductive plate 63, the brush 66, the motor 51, and the brush 67, so the motor 51 is activated and the pinion 52
rotates, and the worm wheel 55 is rotated in the A direction via the gears 53 and 54. When the worm wheel 55 rotates in the A direction, the end surface 58a of the arcuate protrusion 58 comes into contact with the pin 60a of the pin wheel 56, and the pin wheel 56 also rotates in the A direction. and pin 60a
When the position of the pin 60c is 1/3 rotation, the worm wheel 55 and the pin wheel 56 rotate eccentrically, so the arcuate protrusion 58 and the pin 60a come out of contact.Even if the worm wheel 55 rotates,
The pin wheel 56 stops rotating. At this time, the arcuate projection 58 of the worm wheel 55 is
At position 9, the pin 60a of the pin wheel 56 is connected to the pin 60.
It has rotated to position c. At the same time, the pin wheel 56
Notch 63 of conduction plate 63 provided on the opposite side of
As a result of the movement of a, the conduction plate 63 and the brush 65 come out of contact, the supply of current from the battery 72 to the motor 51 is interrupted, and the motor 51 is rendered inactive. Due to the movement of the notch 63a, the hole 34 becomes the hole 3.
2, the chambers 13 and 14 are communicated through holes 25, 23, 36, 34, and 32, and the hydraulic shock absorber 97 has holes 30, 31, and 32 in which hole 31 is the second Since the piston 11 has a large diameter, when the piston 11 moves in the G direction and the H direction,
It produces the second hardest damping force, or intermediate damping force. Thereafter, when the switch 68 is connected to the contact 69 from the state where it was connected to the contact 70, the end face 59a of the arcuate projection 59 that has been moved to the position where the original arcuate projection 58 was located will be replaced by the original pin 60a. It comes into contact with the pin 60b that has been moved to the position where it was, and after a 1/3 rotation, the arcuate protrusion 59 and the pin 60b come out of contact.
The pin wheel 56 is rotated to finally obtain a predetermined soft damping force.

By the way, in the rotary actuator 39,
Pins 60a, 60b, 60c are provided on the pin wheel 56, and when the worm wheel 55 is rotated and the arcuate protrusions 58, 59 are removed from the pins, the pin wheel 5
6 is formed so that it does not engage with the worm wheel 55 temporarily, so that the arcuate protrusion 5
Even after the pins 60a, 60b, 60c are detached from the pins 8, 59 and the current to the motor 51 is cut off, and even if the worm wheel 55 is slightly rotated due to the inertia of the rotor of the motor 51, the pin wheel 56 will not rotate. Therefore, the hole 34 of the shutter 29 is
can be made to match the desired holes 30, 31, 32.

As described above, the pins 60a, 60b, 60c and the arcuate protrusion 58 in this predetermined stopped state
FIG. 5 shows the positional relationship of 59. The positions of the brushes 64, 65, and 66 in this stopped state are set as shown in FIG. In such a state, even if the output shaft 73 attempts to rotate in the opposite direction to A after it has stopped, the arcuate protrusions 58 and 59 will come into contact with the wall surfaces of the pins 60c and 60b, so the worm wheel 55 will remain stationary. As long as the shutter 29 remains in place, the shutter 29 does not rotate due to the stopping force caused by the contact, and the shutter 29 is reliably stationary at the set rotational position. However, in the conventional rotary actuator,
Due to overrun of the motor 51, the worm wheel 55 hits the pin 60c of the end surface 59a of the arcuate protrusion 59.
As shown in FIG. 7a, the end surface 58a of the arcuate protrusion 58 touches the pin 60a.
If the output shaft 73 stops just before it comes into contact with the
The stopping position is set at a predetermined angle, and the circumferential surface 59b of the arc-shaped projection 59 and the pin 60c are in contact with each other. arise. At this time, if the output shaft 73 of the pin wheel 56 attempts to rotate for some reason, the pin 60b can rotate in the direction A by the distance (shown as angle α), resulting in poor positioning accuracy of the output shaft. Become.
Moreover, as shown in FIG. 7b, at this time, the end 63b of the notch 63a of the conductive plate 63 is connected to the brush 64.
In this case, an electrical closed circuit may be formed again, energizing the motor 51, and causing the output shaft 73 to rotate.

The present invention has been made to improve these drawbacks. In the present invention, the arcuate projections 58, 5
9 has been changed from the conventional one, and the end faces 58c and 59c are extended further back than the conventional one, as shown in FIG. 8a. The extended length corresponds to the arc-shaped projection 58 at the point in time when the worm wheel 55 rotates from the predetermined position in FIG. The length is such that the distance between the end surface 58c of the protrusion 58 and the pin 60b forms only the angle β. That is, when the arcuate protrusion 58 abuts the pin 60a, the abutted pin 60a and the pin 6
The worm wheel 55 has a length extending over almost the entire area between the worm wheel 55 and the worm wheel 55 in the rotational direction. The same applies to the other arcuate projections 59. By forming the arcuate protrusions 58 and 59 in this way, the motor 51 may overrun, causing the arcuate protrusions 58 and 59 to
stops just before the end surface 58a of the pin 60a contacts the pin 60a, and even if the output shaft 73 rotates in the direction A for some reason, the pin wheel 56 will continue until the pin 60b contacts the end surface 58c of the arcuate protrusion 58. It can only rotate freely through a small angle β. Furthermore, as shown in FIG. 8b, even if the output shaft rotates as described above, since the angle β is small, the end 63b of the notch 63a of the conductive plate 63 will not come into contact with the brush 64, and it will not close again. It also does not cause the circuit to rotate.

In the above specific example, the pin wheel 56 is provided with a conductive plate 63.
, the brushes 64, 65, 66, 67 are attached to the case 40.
However, the present invention is not limited to this. For example, the pin wheel 56 is provided with brushes 64, 65, 66, 67.
A conductive plate 63 may be provided in the case 40. Furthermore, the present invention is not limited to being used as a drive device for a damping force adjustment mechanism of a hydraulic shock absorber, but can be applied to various other devices.

[Effects of the invention] Since the rotary actuator of the invention has the above-described configuration, when the second rotating body is rotated around the second rotation axis by the motor,
A second protrusion having an arcuate circumferential surface abuts one of the first protrusions at a predetermined position and rotates the first rotating body by a certain rotation angle, and then abuts in the radial direction. As a result, it is possible to reduce the mutual eccentricity of the first and second rotating bodies to configure an intermittent feeding mechanism, and to set the sizes of the first and second rotating bodies small in the radial direction. Therefore, the device to which the rotary actuator of the present invention is applied can be easily made compact. Moreover, if the second protrusion is located between the adjacent first protrusions, the second protrusion Since unnecessary rotation of the first rotating body with respect to the rotating body can be prevented, the positioning accuracy of the first rotating body can be improved.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a preferred embodiment of the present invention, FIG. 2 is a sectional view taken along the line shown in FIG.
3 is a sectional view taken along the line shown in FIG. 1, FIG. 4 is a partially exploded explanatory diagram of the specific example shown in FIG. 1, and FIG. 5 is a predetermined stopping position of the conventional actuator. FIG. 6 is an explanatory diagram showing the relationship between the pin, pin wheel and worm wheel shown in FIG. 1, FIGS. 7a and 7b are explanatory diagrams of the conventional actuator, and FIG. 8a, FIG. 8b is an explanatory diagram of a preferred embodiment of the present invention, and FIG.
A cross-sectional view of a hydraulic shock absorber suitable for the specific example shown in FIG. 1, and FIG. 10 is a cross-sectional view taken along the - line shown in FIG. 9. 55...worm wheel, 56...pin wheel,
58, 59...Circular projection, 60a, 60b, 6
0c...Pin.

Claims (1)

[Scope of utility model registration request] A first rotating body rotatably provided around a first rotating shaft; a plurality of first protrusions, a second rotating body rotatably provided around a second rotating shaft eccentric to the first rotating shaft, and a first rotation of the second rotating body. The first rotating body is rotated by a certain rotation angle by contacting one of the first protrusions of the first rotating body provided on a surface opposite to one side of the body and at a predetermined position. After that, the contact is released in the radial direction, and one of the first protrusions and the other adjacent first protrusion
a second protrusion having an arc-shaped peripheral surface around the second rotation axis;
A rotary actuator comprising a motor connected to a second rotating body to rotate the second rotating body.