JPH0249402B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hydraulic rotary servo actuator in which an output shaft rotates in response to the amount of rotation of an input shaft.

[Prior Art] Conventionally, a rotary servo actuator incorporating a rotary servo valve has been put into practical use as a type of swing-type actuator that operates using a working fluid such as pressure oil. This is inside the housing.
A semi-cylindrical compartment, an output shaft having a vane that divides the compartment into two, and an input shaft fitted into the output shaft are provided, and a rotary servo valve is formed between the output shaft and the input shaft. When the input shaft is rotated, a rotary servo valve opens, supplying pressure oil to one side of the vane in the compartment, and causing the output shaft to follow the input shaft and rotate. It is something.

This rotary servo actuator has a mechanical feedback mechanism built into it, so it can be made compact, has good responsiveness, and requires only a small input torque to rotate the input shaft. It is used in various testing equipment, manufacturing equipment, transportation machines, robots, etc. For example, if the input shaft is connected to a DC servo motor and used as an electro-hydraulic servo motor, a high-output hydraulic drive system can be directly electrically controlled.

[Problems to be Solved by the Invention] However, in the conventional rotary servo actuator as described above, the rotary servo valve is integrally provided, so the problem is that the gain characteristics cannot be easily changed. It was hot.

This gain characteristic refers to the torque generated on the output shaft per unit displacement angle of the input shaft.
This is a factor that governs the responsiveness to displacement signals when used as a hydraulic servo motor. If this responsiveness is too high, vibration may occur and stability may deteriorate.

The allowable inertial load is an indicator of the stability of a rotary servo motor, and this increases as the output of the motor increases and as the gain characteristic decreases, but lowering the gain characteristic too much will result in a loss of output.
Usually, the gain characteristics are set to match the output.

By the way, when choosing the standard of a rotary servo motor according to the purpose of use, it is necessary to consider not only the output determined by the size of the load, but also the allowable inertial load mentioned above. For example, even if the size of the load is the same, , when it is only used in the low speed range, and the stopping accuracy can be low, and there is plenty of output,
Even if a rotary servo actuator cannot be used as it is because its allowable inertial load is low, it may be possible to use it because its allowable inertial load becomes large by lowering its gain characteristics.

Furthermore, it is often desirable to adjust this responsiveness to an appropriate value at the stage when the device is installed.

On the other hand, this gain characteristic is determined by the area that the rotary servo valve opens into the oil chamber when the input shaft is rotated by a unit angle, and the amount of internal leakage that leaks from the sliding part between the blade and the wall in the branch chamber. Therefore, in order to change the gain characteristics of a rotary servo actuator once manufactured, it is necessary to change the axial length of the rotary servo valve's opening or change the amount of internal leakage, which is not easy to do. There was a problem.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides an output shaft rotatably attached to a housing in which two semi-cylindrical compartments are formed by partition walls. A vane is provided to form two oil chambers in each of the branch chambers, an input shaft is inserted into the output shaft, and the supply of pressure oil to each of the oil chambers is controlled between the output shaft and the input shaft. The rotary servo actuator is provided with a rotary servo valve that rotates the input shaft so that the output shaft follows the input shaft. A flow rate adjustment valve and a check valve that restricts the oil flow to the same compartment direction are installed between the oil chambers, and when one check valve stops the oil flow, the other check valve allows the oil flow. It is connected like this.

[Operation] When the input shaft is rotated and a pressure difference is created between the oil chambers, an oil flow is generated through the flow rate adjustment valve, and the gain is reduced. Since this amount of gain reduction can be controlled by the flow rate adjustment valve, it can be adjusted as necessary without changing the valve, and the stability of the control system can be increased.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. In these figures, the reference numeral 1 is an output shaft rotatably mounted on the housing 2, the reference numeral 3 is an input shaft fitted coaxially with this output shaft, and the reference numeral 4 is the output shaft 1. and a rotary servo valve formed between the input shaft 3, and reference numeral 5 denotes a partition wall that divides the inside of the housing 2 into two compartments 6, 6, and that pivotally supports the output shaft 1 in a liquid-tight manner. It is fixed to the output shaft 1, divides the branch chamber 6 into two oil chambers 8, 8, and divides the branch chamber 6 into two oil chambers 8, 8.
This is a vane that slides liquid-tightly on the peripheral wall 9 of.

The rotary servo valve 4 communicates a pressure oil supply path 10 and a pressure oil discharge path 11 formed in the input shaft 3 with the oil chamber 8 as the input shaft 3 rotates as shown in FIG. As shown in FIG. 1, there are a pair of supply ports 12, 12 and a discharge port 13, 13 that open on the outer surface of the input shaft 3, and four ports that open on the inner surface of the output shaft 1 and communicate with each oil chamber 8. It is composed of a communication port 14... The circumferential interval between the supply port 12 and the discharge port 13 is set approximately equal to the opening length of the communication port 14, and as shown in FIG. When the directions match, the communication port 14 does not communicate with anything. In addition, as shown in Fig. 3, the input shaft 3
When the vane 7 is rotated, the discharge port 13 communicates with the communication port 14 on the rotation side, and the supply port 12 communicates with the communication port 14 on the opposite side, and the pressure on both sides of the vane 7 changes, causing the output shaft 1 to As shown in FIG. 4, the vanes 7 are rotated until they are lined up in the direction of the supply port 12 of the input shaft 3.

Reference numeral 15 denotes a pressure pipe 16 provided in a pipe 16 that communicates between the adjacent oil chambers 8, 8 across the partition wall 5.
It is a temperature compensated flow rate regulating valve, and reference numeral 17 is a check valve that limits the oil flow to the same compartment direction. This pipe 16 is provided near the partition wall 5 of the oil chamber 8. The flow rate regulating valve 15 is configured to allow a constant flow rate to flow at a constant pressure difference regardless of temperature or pressure, and the flow rate can be easily controlled by opening and closing the valve.

Next, the operation of the rotary servo actuator configured as described above will be described.

When the input shaft 3 is rotated as shown in FIG. 3 from the neutral state shown in FIG. The side communication ports 14b, 14b have supply ports 12, 12
is communicated. As a result, a pressure difference is created between adjacent oil chambers, causing the vane 7 to rotate on the one hand, and at the same time, the piping 16 shown by arrow B in FIG.
Oil flow to the flow rate adjustment valve 15 and check valve 17 occurs.
Therefore, by changing the opening degree of the flow rate regulating valve 15 and adjusting the amount of external leakage to an appropriate value, it is possible to change the characteristics of the torque (gain) generated on the output shaft 1 per unit variation angle of the input shaft 3. can. The output shaft 1 is rotated by the torque thus adjusted until it returns to the neutral position as shown in FIG. Moreover, when the input shaft is rotated in the opposite direction, the flow rate adjustment valve 15 and the check valve 1 on the opposite side are
An oil flow to 7 occurs and has a similar effect.

As can be understood from the above configuration and operation, according to this rotary servo actuator, the gain characteristics can be changed by adjusting the opening degree of the flow rate adjustment valve, so it can be adjusted depending on the usage situation. A servo actuator with tailored servo characteristics can be provided.

[Effects of the Invention] The present invention is characterized in that an output shaft is rotatably attached to a housing in which two semi-cylindrical compartments are formed by partition walls, and a blade is provided on the output shaft to form two oil chambers in each of the compartments. A rotary servo valve is provided between the output shaft and the input shaft to control the supply of pressure oil to each of the oil chambers, and the input shaft is rotated. In a rotary servo actuator in which the output shaft rotates following the input shaft, a flow rate adjustment valve and a same oil flow are provided between oil chambers adjacent to each other across the partition wall. Each compartment is provided with a check valve that restricts the oil flow, and when one check valve stops the oil flow, the other check valve allows the oil flow, so the input shaft can be rotated. When a pressure difference is created between the oil chambers, an oil flow is generated through the flow rate adjustment valve, and the gain changes. Since this amount of gain change can be controlled by the flow rate adjustment valve, it can be adjusted as necessary without changing the valve, and the stability of the control system can be increased. As a result, it is possible to provide a servo actuator with servo characteristics suitable for the usage situation, which is an excellent effect.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention,
FIG. 2 is a side sectional view, and FIGS. 3 and 4 are explanatory diagrams of its operation. 1... Output shaft, 2... Housing, 3... Input shaft, 4... Rotary servo valve, 5... Partition wall, 6... Separate chamber, 7... Vane, 8... Oil chamber, 1
5...Flow rate adjustment valve, 17...Check valve.

Claims (1)

[Claims] 1. An output shaft 1 is rotatably attached to a housing 2 in which two semi-cylindrical compartments 6 are formed by a partition wall 5, and a vane 7 is provided on this output shaft 1 to form two semi-cylindrical compartments 6.
Two oil chambers 8 are formed in the interior, and the input shaft 3 is inserted into the output shaft 1, and the output shaft 1 and the input shaft 3 are connected to each other.
A rotary servo valve 4 for controlling the supply of pressure oil to each of the oil chambers 8 is provided between them, and by rotating the input shaft 1, the output shaft 1
In the rotary servo actuator which rotates following the input shaft 3, a flow rate adjustment valve 15 and an oil flow direction are provided between the oil chambers 8 which are adjacent to each other with the partition wall 5 in between. A rotary servo actuator characterized in that check valves 17 are respectively provided to restrict the oil flow, and are connected so that when one check valve 17 stops the oil flow, the other check valve 17 allows the oil flow.