JPH0341711B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a direct-acting rotary servo valve, and particularly to a valve configuration suitable for imparting damping to a movable part.

[Conventional technology]

As a direct-acting rotary servo valve, JP-A-61-
Using a rotary valve as described in No. 153074,
Detects the angular displacement of the valve body and uses feedback to determine the position of the valve body, as well as detects the angular velocity of the valve body.
A method was adopted in which damping was applied to the movable parts by feedback.

[Problem to be solved by the invention]

However, this method uses an angular velocity detector, which not only complicates the valve structure and increases its size, but also requires a control circuit for angular velocity signal feedback, which makes the control device complicated and expensive. There was a problem.

An object of the present invention is to provide a direct-acting rotary servo valve that can provide damping to a movable part without requiring angular velocity detection, in order to solve the problems of the prior art as described above.

[Means to solve the problem]

The above object is achieved by filling a viscous fluid between the rotor, which is integrally coupled to the valve body, and the magnet and yoke that constitute the magnetic circuit.

[Effect]

According to the present invention, when the rotor rotates, a velocity gradient is generated in the fluid near the rotor, and shear stress is generated in the fluid due to the viscosity of the fluid, and this shear stress causes the rotor to rotate. A moving resistance force acts.
At this time, since the shear stress is proportional to the velocity gradient, a braking force proportional to the angular velocity acts on the rotor and the valve body connected thereto. In this way, the viscosity of the fluid can provide damping, or damping, to the movable part.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 is a longitudinal cross-sectional view showing an embodiment of a direct-acting rotary servo valve according to the present invention, and FIG. 2 is an A of FIG. 1.
3 is a sectional view taken along line B-B in FIG. 1.

A valve body 2 is rotatably provided within the casing 1, and a disc-shaped rotor 3 is integrally connected to a portion of the valve body 2. On the other hand, the magnet 4 and the yoke 5 constitute a magnetic circuit, and the rotor 3 is arranged to be sandwiched between the magnet 4 and the yoke 5 with a predetermined gap therebetween.
Further, the valve body 2 is provided with control chambers 6 and 7, and the casing 1 is provided with a supply port 8, a discharge port 9, and control ports 10 and 11. Furthermore, an angular displacement detector 12 is connected to one end of the valve body 2, and a torsion spring 13 is integrally connected to the other end. It is configured so that the neutral position can be adjusted and fixed. A space 15 between the rotor 3 and the magnetic circuit composed of the magnets 4 and the yoke 5 is filled with viscous fluid, and this fluid is separated from the working fluid controlled by the valve. A sealing member 16 is provided at. In addition, as shown in Fig. 2, the rotor 3 has a plurality of windings 3a arranged at square pitches in the circumferential direction, and the winding direction of the winding 3a is opposite to that of the three adjacent windings. It is configured to be oriented in the direction of Further, the magnets 4 are configured to have the same angular pitch as the winding 3a, but have opposite polarities alternately in the circumferential direction.

Next, the operation of this embodiment will be explained.

As shown in FIG. 2, in the neutral state, the rotor 3 is set at a position where the boundary of the winding 3a is shifted by an angle θ=/2 with respect to the dividing position of the magnet 4.

When current is passed through the winding 3a placed in the magnetic field, an electromagnetic force is generated. At this time, since the windings 3a are configured so that the winding directions are alternately opposite, the current flows in the direction of the arrow 17. On the other hand, as shown in the figure, the magnets 4 are constructed so that the polarities are alternately opposite in the circumferential direction, so that the directions of the magnetic fields are alternately opposite. Therefore, all the electromagnetic forces acting on the winding 3a are in the same direction, and as a result, a rotating force in the direction of the arrow 18 is generated in the rotor 3.
This rotational force also causes the valve body 2 to rotate in the direction of the arrow 18. At this time, as shown in FIG.
The control chamber 6 is connected to the supply port 8 which communicates with the actuator, and the control chamber 7 is connected to the discharge port 9. Therefore, as shown by the arrows in the figure, the working fluid is supplied to the control port 10 and the control port 11
is discharged from. On the other hand, if the direction of the current flowing through the winding 3a is reversed, the rotational force will be in the opposite direction,
Since the valve body rotates in the direction opposite to the arrow 18, the working fluid is supplied to the control port 11 and discharged from the control port 10. Therefore, by controlling the direction and magnitude of the current flowing through the winding 3a, the rotor 3 and the valve body 2 can be rotated in an angular range of ±θ, and the angular displacement detector 12 can be used to rotate the valve body 2. By detecting and feeding back the angular displacement of the body 2, it is possible to accurately position the valve body and control the flow direction and flow rate of the working fluid. but,
In order to control at higher speeds, oscillation phenomena will occur unless appropriate damping is applied to the movement of the rotor 3 and other movable parts. However, in this embodiment, since the space 15 between the rotor 3 and the magnetic circuit composed of the magnets 4 and the yoke 5 is filled with viscous fluid, when the rotor 3 rotates, it rotates. Since a velocity gradient occurs in the fluid near the rotor 3, shear stress proportional to the velocity gradient is generated in the fluid due to the viscosity of the fluid, and this shear stress causes the angular velocity to change with respect to the movement of the rotor 3 and the valve body A control force or damping force proportional to This allows for faster and more accurate control of the flow of the working fluid.

Therefore, according to this embodiment, damping can be applied to the movable part without requiring angular velocity detection,
Not only does the valve structure become simpler, making it smaller and more expensive, but also the control device becomes simpler and less expensive because a control circuit for angular velocity signal feedback is not required.

Note that the viscous fluid for obtaining damping may be the same as the working fluid, and in this case, the sealing member 16 shown in FIG. 1 becomes unnecessary.

Moreover, as shown in the fourth example, the fluid for obtaining damping may be a magnetorheological fluid 19.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to apply damping to the movable part without requiring angular velocity detection, which not only simplifies the structure of the valve, makes it compact and inexpensive, but also enables angular velocity signal feedback. Since there is no need for a control circuit for this, the control device is simple and inexpensive, which provides not only technical but also economic benefits.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view showing a direct-acting rotary servo valve according to an embodiment of the present invention, and FIG. 2 is a line taken along line A-A in FIG.
3 is a sectional view taken along line BB in FIG. 1, and FIG. 4 is a longitudinal sectional view showing a direct acting rotary servo valve according to another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Casing, 2... Valve body, 3... Rotor, 4... Magnet, 5... Yoke, 15... Space filled with fluid, 19... Magneto-rheological fluid.

Claims (1)

[Claims] 1. A casing, a valve body rotatably provided within the casing, a rotor integrally coupled to the valve body, and a magnet and yoke constituting a magnetic circuit for rotating the rotor. A direct-acting rotary servo valve comprising: a viscous fluid between the rotor, the magnet, and the yoke.