JPS58163804A - Rotary servo actuator - Google Patents

Abstract

PURPOSE:To maintain an output shaft in a free rotational state when a by-path communicates with a hydraulic chamber, by causing the input shaft of a rotary servo actuator to be movable axially and providing said input shaft with a by- path which prepares connection among hydraulic chambers. CONSTITUTION:An input shaft 2 is fitted rotatably and slidably into an output shaft 1. On said input shaft 2, annular grooves 14, 16, 21 as well as a by-path 24 are formed. On the other hand, said output shaft 1 is provided with penetrating bores 17, 19, 22 and when said input shaft 2 is placed at the right position, said annular grooves 14, 16, 21 communicate with the penetrating bores 17, 19, 22. When said input shaft 2 is slid to the left, a by-path 24 communicates with change over passage 5-8 of the output shaft 1 although the above communication is cut off, and each hydraulic chamber (A-D) is connected to each other. Thus, said output shaft 1 is in a free rotational state.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a rotary servo actuator in which an output shaft is strongly rotated by hydraulic pressure in accordance with the rotational displacement of an input shaft, and the output shaft can be freely rotated as required. It is related to.

In the conventional rotary servo actuator, the first
- to those shown in FIG. 3 are known. However, in such an actuator, the output shaft cannot be freely rotated.

Therefore, first, this conventional actuator will be explained. In this case, a human power shaft 2 is fitted into an output shaft 1, and these are coaxially provided in a housing 3. Inside, there are two fan-shaped sections forming a central angle of 180 degrees.
A total of two vanes 4.4 are provided in a local area of the output shaft 1 to divide each space into two.
It is provided in a protruding manner along one diameter line. As a result, the two spaces inside the housing 3 are divided into a total of four oil chambers AB, C,
D is recessed, and each of these oil chambers is connected to the output shaft 11.
a switching passage 5 provided at a distance of 1 m and facing the outer surface of the input shaft 2;
6, 7.8, respectively. The switching passages 5.6 and 7.8 are arranged on the outer circumferential surface of the input shaft 2 at equally spaced positions along the local direction of the input shaft 2, that is, at four positions having a central angle of 90° to each other. It is shaped so that you can face it.

On the other hand, on the outer peripheral surface side of the input shaft 2 facing each of the switching passages 5.6, 7.8, four hydraulic pressure introduction holes 9.1G, 11.12 are provided at equal intervals along the local direction. There is. A pair of hydraulic pressure introduction holes 9 and 10 facing each other about the axis of the input shaft 2 are connected to the annular groove of the coil 1 on the outer circumferential portion of the input shaft 2 on the left side in FIG. 14, and another set of hydraulic pressure introduction holes 11, 12 facing each other around the axis of the input shaft 2 are connected to the input shaft 2 in FIG. They are respectively communicated with the second annular groove 16 in the left outer circumference.

The first annular groove 14 communicates with the hydraulic oil supply port 18 of the housing 30 via the first through hole 17 of the output shaft 1 . The first annular $ 14 and the through hole 17 always maintain communication regardless of the relative rotational displacement between the output shaft 1 and the input shaft 2, and the through hole 17 and the inlet 18 are connected to at least the housing 3. The state of communication with each other is maintained within the rotation range of the output shaft 1 relative to the rotation range of the output shaft 1. Afterwards, the first
The annular i$ 114 is always communicated with the supply port 18 regardless of the rotation of the output shaft 1 and the input shaft 2.

On the other hand, the second annular #116 is connected to the hydraulic oil outlet 20 of the housing 3 through the second through hole 19 of the output shaft 1, and is located in the annular groove 16 of II2. ,
The output shaft 1 and the input shaft 20 are always connected to the exhaust port 20 regardless of rotation.

Among them, the reference numeral 21 in FIG. 1 indicates an annular groove of the drain strip 3 provided on the input shaft 2, and this annular groove 21 is connected to the housing 3 through the third through hole 22 of the output shaft 1. It communicates with the drain port 23.

According to the conventional actuator constructed in this way, the set of hydraulic pressure introduction holes 9.10 on the input shaft 2 side always has a supply of 0.
Hydraulic pressure from nine hydraulic power sources (not shown) connected for 18 km is introduced, and the other set of hydraulic pressure introduction holes 11.1 on the input shaft 2 side
2 is always connected from the outlet 20 to the hydraulic oil return section of the hydraulic power source.

Then, when the input shaft 2 is rotated from side to side with the rotational position shown in FIG. 3(a)K being in a neutral state, the output shaft 1 follows this rotation and makes one powerful turn.

That is, when the input shaft 2 is in the neutral position as shown in FIG. It is disconnected from each switching channel 5.6.7.8. At this time, the oil chambers B, C, and D have the same volume and have the same internal pressure, and the output shaft l is firmly held at the neutral position as shown in Figure II 3 (a). .

Now, when the input shaft 2 is rotated to the right as shown in FIG. 3(b), each hydraulic pressure introduction hole 9,
10, 11.12 and the switching passages 5.6° and 7.8 are mutually switched, pressurized oil is introduced into the oil chambers M and C, and oil in the oil chambers B and D is discharged. As a result, the output shaft 1 is strongly rotated to the right by the hydraulic pressure, and each hydraulic pressure introduction hole 9
．． 10.degree. 11.12 and the switching channels 5, 6, 7.8 are again interrupted as shown in FIG. 3(e), the output shaft 1 is stopped and held firmly.

Among them, when the input shaft 2 is rotated to the left, oil iiB,
Pressurized oil is introduced into D, and the oil in oil chambers A and C is led out, and the output shaft 1 is powerfully rotated to the left by the oil pressure.

In this way, the output shaft l rotates the same as the input shaft 2,
It stops at the same time as this input shaft 2 stops. Furthermore, if pressure oil is supplied, as long as the input shaft 2 is stopped, the output shaft 1 will remain fixed and hardly move even when a load is applied.

Incidentally, in recent years, in addition to the above-mentioned rotary servo actuator, there has been a desire for the emergence of one in which the output shaft 1 can be made into a freely rotating portion as required. This is for example as an actuator integrated into the knee of a prosthetic leg. In other words, the skin actuator of this prosthetic leg requires a large torque when a person stands up or climbs or descends stairs, but when running on a flat surface, the actuator acts as a kind of pendulum motion due to the swinging of the hip joint. This is because no torque is required for this purpose.

Therefore, for the actuator as described above, a switching valve that forms bypass passages for each oil chamber M, B, C, and Do via a throttle valve, and piping between the hydraulic power source and the supply port 18 and the discharge port zO are installed. A configuration can be considered in which a closing switching valve is newly attached, and the output shaft 1 is set in a free rotation state by Mokoto K, who operates these throttle valves and two switching valves as necessary. .

However, such a configuration causes problems such as the actuator itself being large and heavy, requiring special piping work outside the actuator, and having troublesome valve operations. This is extremely inconvenient, especially as a knee actuator for a prosthetic leg that is required to be small and lightweight.

This invention was made in consideration of the above circumstances, and
By making the input shaft movable along its axis and by providing the input shaft with a bypass passage that communicates with each oil chamber, the output shaft can be moved based on the movement of the input shaft in the axial direction. The actuator can be brought into a free-rotating state extremely easily, and there is no need for special external piping, and the actuator itself can be made small and lightweight, making it especially suitable for use in the IIIK of prosthetic legs. The purpose of the present invention is to provide a rotary servo actuator that is extremely suitable for use as a rotary servo actuator.

An embodiment of the present invention will be described below with reference to FIGS. 4 and 5.

By constructing this embodiment, the input shaft 2, which is different from that of the conventional example described above, can be moved in the left and right directions along its axis, and an L-shaped bypass passage 24 is formed on the right side periphery of the input shaft 2. is provided. The rest of the configuration is the same as that of the conventional example described above, so a description thereof will be omitted.

In this embodiment, the input shaft 2 is located to the right of the output shaft 1 as shown by the two-dot chain line in FIG.
), the annular grooves 14° 16.21 on the left side of the input shaft 2 are connected to the through holes 17° 19° 220 of the output shaft 1, respectively, as in the conventional spinning example. The hydraulic pressure introduction holes 9.10, 11. of the input shaft 2 are opposed to each other.
12 is located on the same circumference as each switching passage 5, 6, 7.8 of the output shaft 1.

In addition, a new bypass passage 24 is provided for each switching passage of the output shaft 1 @
It is positioned to the right of 5.6 and 7.8.

On the other hand, when the input shaft 2 is at the leftward movement limit position with respect to the output shaft 1 as shown by the solid line in FIG. Through hole 17
．． 19. Shifted to the left from 22, each of these annular grooves 14,
16.21 are closed by the inner circumferential surface of the output shaft 1, and the hydraulic pressure introduction holes 9.1G and 11.12 of the input shaft 1 are connected to the left side from each switching passage 5, 6, 7.8 of the output shaft 10. Shift in,
These oil pressure introduction holes 9.1G and 11.12 are closed by the inner peripheral surface of the output shaft 1, and the bypass passage 24 is in the same circle as each switching passage 5, 6, 7.8 of the output shaft 1. It is located on the circumference.

Therefore, with this configuration, when the input shaft 2 is at the rightward movement limit position, the 11 actuators operate in the same manner as in the conventional example described above. When the oil chambers A, B, C, and D are closed, the bypass passage 24 is opened to each switching passage 5, 6,
．． The insides of the oil chambers A, B, C, and D are communicated with each other through the oil chambers 8.

Therefore, when the input shaft 2 is at the leftward movement limit position, the output shaft 1 is in a freely rotating state in which it can rotate with a small force that resists the frictional resistance inside the actuator. Maku,
At this time, the connection between the hydraulic pressure introduction hole 5°6.7.8 of the input shaft 2 and the hydraulic pressure source is cut off.

In addition, depending on the amount of extraction to the left of the input shaft 2, each oil i [A, B, C, D slow process rate,
That is, by adjusting the flow rate of the hydraulic oil in and out of the bypass passage 24, it is possible to change the resistance torque against the rotation of the air and output shaft 1.

Note that in the above embodiment, the output shaft 1 is brought into a free rotating state by pulling out the input shaft 2 to the left, but conversely, by pushing the input shaft 2 to the right, the output shaft 1 is brought into a free rotation state. It is also possible to configure it to be in a free rotation state, and in this case, for example, the location where the bypass passage 240 is formed on the input shaft 2 may be changed. Friend, the form of this bypass passage 24 is arbitrary, and the point is that the input shaft 2
QIt is sufficient if the oil chambers are communicated with each other by movement in the axial direction.

Further, the present invention is applicable not only as an actuator incorporated in a knee of a prosthetic leg, but also as an actuator of various types and for various uses, such as a simple hydraulic swing motor.

Also, the main issue #4 is the actual #1 above! The actuator is not limited to a so-called double vane type actuator having two vanes 4.4 on the output shaft 1 as in the example, but for example, one vane on the output shaft 1.
It is also applicable to a so-called single vane type actuator having two vanes.

As explained above, according to the rotary servo actuator according to the present invention, the input shaft is movable along its axis, and the input shaft is provided with a bypass passage that communicates between the oil chambers. By moving the input shaft in its axial direction, the output shaft can be brought into a free rotating state very easily, and there is no need for special external piping, and the actuator itself can be made small and lightweight. In particular, it is extremely suitable as an actuator to be incorporated into the knee of a prosthetic leg.

[Brief explanation of drawings]

Fig. tg is a vertical cross-section m#A showing an example of a conventional rotary servo actuator; FIG. 4 is a longitudinal cross-sectional view showing an embodiment of the present invention, and FIG. 5 is a cross-sectional view taken along section 1--2 of FIG. 4. 1...Output shaft, 2...Input shaft, 24.
...Bypass passage, A, B, C, D-...
Oil room. Bamboo rod Makoto Ishiita

Claims (1)

[Claims] A rotary system that selectively introduces hydraulic pressure into a plurality of oil chambers by valve operation based on the rotation of an input shaft, and uses a pressure difference Kt between the plurality of oil chambers to powerfully rotate an output shaft in correspondence with the input shaft. In the servo actuator, the input shaft is movable along its axis, and the input shaft is provided with a bypass passage that communicates the plurality of oil chambers with each other, and the input shaft is provided with a bypass passage that communicates with each other in the axial direction of the input shaft. When the bypass passage communicates with the plurality of oil chambers due to movement,
A rotary servo actuator, characterized in that the output shaft is in a free rotation state.