JPH08326705A - Motorized hydraulic actuator - Google Patents

Abstract

PURPOSE: To improve reliability and EMI(electromagnetic interference)-resistance of an actuator by providing a controller which inputs the output of a position detector of a control piston and an actuator as a feedback input and sends a control signal to a servo valve by a position command signal. CONSTITUTION: A variable swash plate type hydraulic pump 4 is driven by an AC motor 3 in a specified direction at a specified speed. When a position command signal 2s is input into a controller 2, the controller 2 receives this signal and feedback signals from a position detector 5a, 5 of a control piston 14 and an actuator 6 to send a control signal responsive to the position command signal 2s to a servo valve 8. The servo valve 8 operates a variable swash plate via the control piston 14 in response to the input. Accordingly, the variable swash plate type hydraulic pump 4 changes discharging amount of flow and direction in response to the control signal to operate the actuator 6. The controller 2 indirectly controls the hydraulic pump 4 via a servo valve 8 having small inertia without controlling the AC motor 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrohydraulic actuator applied to motion control of an all-electric aircraft.

[0002]

2. Description of the Related Art A conventional electric hydraulic actuator for an aircraft is shown in FIG. An actuator 6 is connected to a fixed swash plate type hydraulic pump 12 driven by a DC motor 11. The actuator 6 has a position detector 5, the output of which is sent to the controller 10. The output of the controller 10 is sent to the DC motor 11. In the figure, 9 is a DC power source,
13 is an accumulator.

In the above, the controller 10 receives the position command signal 10s of the actuator and the feedback signal from the position detector 5, and receives the DC motor 1
1 is driven according to the position command signal 10s. The pump 12 is driven by the DC motor 11, and the actuator 6 operates. That is, the actuator 6 was controlled by directly controlling the DC motor 11.

[0004]

The above-mentioned conventional electrohydraulic actuator controls the movement of the actuator by directly controlling the rotation direction and speed of the DC motor via the controller. Therefore, the controller requires a large-capacity switching element, and the reliability of this element is low and the electromagnetic noise level is also high. Therefore, the reliability of the actuator and the resistance to EMI (electromagnetic interference) are high.
There was a problem in terms of sex.

[0005]

The present invention employs the following means to solve the above-mentioned problems.

That is, as an electric hydraulic actuator, a variable swash plate type hydraulic pump driven by an AC motor,
A control piston connected to a variable swash plate of the variable swash plate type hydraulic pump and connected to a servo valve, an actuator connected to the variable swash plate type hydraulic pump, a position detector of the control piston, and the position of the actuator. A controller is provided which feeds back the output of the detector and sends a control signal to the servo valve by a position command signal.

[0007]

In the above invention, the variable swash plate type hydraulic pump is A
It is rotationally driven in a fixed direction by the C motor. When the position command signal is input to the controller, the controller receives this signal and the feedback signal from the position detector of the control piston and the actuator, and sends a control signal corresponding to the position command signal to the servo valve. The servo valve actuates the variable swash plate via the control piston in response to the input. Therefore, the variable swash plate type hydraulic pump changes the discharge flow rate and the direction according to the control signal to operate the actuator.

As described above, the controller indirectly controls the hydraulic pump via the servo valve having a small inertia without controlling the AC motor. This reduces the electromagnetic noise level. Further, the capacity of the switching element of the controller can be reduced, and the reliability of the element itself is improved.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIG. Variable swash plate type hydraulic pump 4 driven by AC motor 3
Is provided. The control piston 14 is connected to the variable swash plate of the hydraulic pump 4 and is also connected to the servo valve 8. An actuator 6 is connected to the hydraulic pump 4.

A charge pump 1 that works together with a hydraulic pump 4.
6, a reservoir 7 and a servo valve 8 are connected.

The controller 2 receives the position command signal 2s,
The outputs of the position detectors 5 and 5a of the actuator 6 and the control piston 14 are feedback input. 1 in the figure
Is an AC power source, and 15 is a DC power source.

In the above, the variable swash plate type hydraulic pump 4 is rotationally driven by the AC motor 3 in a fixed direction at a fixed speed.
When the position command signal 2s is input to the controller 2, the controller 2 receives this signal and the feedback signals from the position detectors 5a, 5 of the control piston 14 and the actuator 6, and performs control according to the position command signal 2s. Send a signal to the servo valve 8. The servo valve 8 operates the variable swash plate via the control piston 14 according to the input. Therefore, the variable swash plate hydraulic pump 4 changes the discharge flow rate and the direction according to the control signal, and operates the actuator 6.

As described above, the controller 2 has the AC
Servo valve 8 with small inertia without controlling motor 3
The hydraulic pump 4 is indirectly controlled via the. This eliminates the need for high current switching and reduces the electromagnetic noise level. Further, the capacity of the switching element of the controller can be reduced, and the reliability of the element itself is improved.

[0014]

According to the present invention as described above,
Since the controller does not control the motor, the capacity of the switching element of the controller can be reduced. Therefore, the electromagnetic level is lowered and the reliability is improved without the problem of ECI.

[Brief description of drawings]

FIG. 1 is a configuration circuit diagram of an embodiment of the present invention.

FIG. 2 is a configuration circuit diagram of a conventional example.

[Explanation of symbols]

1 AC power supply (equipment for aircraft) 2 Controller (AC motor compatible) 3 AC electric motor 4 Variable swash plate type hydraulic pump 5 Position detector 6 Hydraulic piston / cylinder (actuator) 7 Reservoir 8 Servo valve 9,15 DC power supply (body) Equipment) 10 Controller (DC motor compatible) 11 DC electric motor 12 Fixed swash plate type hydraulic pump 13 Accumulator 14 Swash plate angle control piston 16 Charge pump

Claims (1)

[Claims] 1. A variable swash plate type hydraulic pump driven by an AC motor, a control piston connected to the variable swash plate of the variable swash plate type hydraulic pump and connected to a servo valve, and the variable swash plate type hydraulic pump. An actuator connected to a pump, and a controller that feeds back the output of the position detector of the control piston and the position detector of the actuator, and sends a control signal to the servo valve by a position command signal. Electro-hydraulic actuator to.