JPH01288675A - Control valve - Google Patents

Abstract

PURPOSE:To obtain a compact valve which can completely shut off a fluid in a system for controlling a gas quantity in the gas piping system of a boiler, etc. by providing a screw shaft on a valve to valve seat and rotating a nut fitted on the screw shaft by means of a piezoelectric driving device, to drive the valve in the axial direction. CONSTITUTION:A valve 10 is provided opposite to a valve seat 11a formed in a valve body 1. A nut 8 on which a rotary disk 6 is installed is screwed on a screw shaft 7 installed on the valve 10. The rotary disk 6, together with a ring type elastic body 5 in which a ring type piezoelectric element 4 is stuck on the back thereof, is held between flanges 17, 18. As a high frequency voltage is applied to the piezoelectric element 4, a progressive wave is formed in the elastic body 5, rotating the rotary disk 6 to drive the valve stem 7 via the nut 8.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a control valve that shuts off the flow of gas, liquid, etc., and adjusts pressure or flow rate.

[Conventional technology]

A system that controls the amount of gas in boilers, various air conditioners, industrial furnace gas piping systems, etc. generally consists of a temperature sensor, a control circuit, an actuator, and a valve.

As the actuator, conventional servo motors and fJ
Although IN coils are used, they are not fully satisfactory in terms of controllability, particularly responsiveness.

On the other hand, piezoelectric drive devices that drive piezoelectric elements with high-frequency voltages in the ultrasonic range, ie, ultrasonic motors, have been put into practical use and have excellent features such as small size, light weight, high torque, and high responsiveness. When this is combined with a valve, even the actuator can be housed within the piping, making it possible to construct a compact control valve with excellent controllability.

FIG. 3 shows an example of a conventional control valve using an ultrasonic motor (Japanese Patent Application No. 61-248069).

This control valve includes a fixed disk 35 having an opening 35a in a part of the valve body 33, which is a tubular valve body whose inside becomes a flow path, and which blocks the flow path.
A rotary disk 36 is rotatably provided with one side in contact with the fixed disk 35, and has an opening 36a whose communication opening area with respect to the opening 35a of the fixed disk 35 changes as the rotation angle changes; The ultrasonic motor 37 is attached to the rotary disk 36 and rotates the rotary disk 36. The ultrasonic motor 37 includes a ring-shaped elastic body 38, a ring-shaped piezoelectric element 39 attached to the back surface of the elastic body 38, and the rotating disk 36. 40 is a sealing material presser, 41
43 is a sealing material such as an O-ring, and 44 is a lead wire connected to the electrode of the piezoelectric element 39.

According to this configuration, by rotating the rotating disk 36 with the ultrasonic motor 37 and changing the position of the opening 36a of the rotating disk 36 with respect to the opening 35a of the fixed disk 35, opening/closing of the valve and adjustment of the flow rate can be performed. I can do it.

FIG. 5 shows an example of a cylindrical valve using an ultrasonic motor. Rotating disc 52 and fixed disc 5 inside valve body 51
3 are provided with cylindrical portions 52a and 53a, and openings 54 and 55 are provided therein.
It is formed. 57 is a ring-shaped elastic body, and a piezoelectric element 58 is adhered to the back surface thereof. The operation is similar to the example shown in FIG.

[Problem to be solved by the invention]

In the conventional example shown in FIG. 3, as shown in FIG.
5 and the rotating disk 36, the fully closed state is established, that is, the opening 36a of the rotating disk 36 is at the farthest position where it does not communicate with the opening 35a of the fixed disk 35. In this situation, fluid would flow through the gaps 45 between these discs 35, 36, making it difficult to completely shut off the fluid flow. If the rotating disk 36 is strongly pressed against the stationary disk 35 in order to prevent leakage, the frictional force increases and the torque of the ultrasonic motor 37 becomes insufficient.

In the example shown in FIG. 5 as well, leakage occurs between the fixed disk 53 and the movable disk 52 as described above.

An object of the present invention is to provide a control valve that can be completely shut off without causing leakage in a fully closed state and that can be constructed compactly.

[Failure to solve the problem]

The control valve of the present invention is provided with a valve body that faces a valve seat of a valve body and moves toward and away from the valve seat, and this valve body is driven by a piezoelectric drive device via a feed screw mechanism. The feed screw mechanism includes a screw shaft that is supported to move forward and backward and has a valve body at its tip, and a nut that is screwed onto the screw shaft. The piezoelectric drive device includes a ring-shaped rotating disk to which the nut is attached, an elastic body in contact with the rotating disk, and a piezoelectric element that excites the elastic body to rotate the rotating disk.

[Effect]

According to the configuration of this invention, by rotating the nut of the feed screw mechanism with the rotary disk of the piezoelectric drive device, the valve body moves forward and backward together with the screw shaft to open and close the opening. Since the valve body is opened and closed via the feed screw mechanism, the valve body can be strongly pressed against the inner surface of the opening with a small torque.

〔Example〕

An embodiment of the present invention will be described based on FIGS. 1 and 2.

The valve body 1 is composed of a part of the pipes IA and IB joined at the neck part 3. A partition wall 2 is provided in the pipe IB, and an opening 11 whose inner surface is a valve seat is provided at the center of the partition wall 2. The valve seat 11a has a tapered conical shape. The valve body 10 is formed into a truncated cone shape that fits into the valve seat 11a,
It is integrally formed at the tip of the screw shaft 7. The screw shaft 7 has a rear end 7a formed in a non-circular shape (see FIG. 2), and is supported by a support member 12 within the valve body 1 so as to be able to move forward and backward. The support member 12 includes a fitting part 12b into which the rear end 7a is fitted, and an arm part 12 which extends radially from the fitting part 12b and is fixed to the valve body l.
It consists of a. A nut 8 is screwed into the male threaded portion 7b of the screw shaft 7, and the naso 1-8 is fixed to the rotating disk 6 of the piezoelectric drive device 15 via an arm 9.

A feed screw mechanism 16 is constituted by the screw shaft 7 and the naso l-8.

The piezoelectric drive device 15 is constructed by stacking a ring-shaped elastic body 5 with a ring-shaped piezoelectric element 4 attached to the back surface and the rotating disk 6 and sandwiching it between the flanges 17 and 18 of the pipes IA and IB. be. A sealing material 13 such as an O-ring is interposed between the piezoelectric element 4 and the flange 15. 14 is a tow line connected to the piezoelectric element 4;

The operating principle of the piezoelectric drive device 15 will be briefly explained.

The elastic body 5 is made of a metal material such as iron, and the portion on the rotating disk 6 side is formed with a large number of protrusions (not shown) arranged in a row of teeth. The piezoelectric element 4 is obtained by processing a piezoelectric ceramic material into a thin plate shape, and polarizing the piezoelectric ceramic material uniformly in the thickness direction. A plurality of electrodes (not shown) are arranged in the circumferential direction of the piezoelectric element 4 with a pinch of half the wavelength of the bending vibration, and a high frequency voltage at a resonant frequency is applied to the electrode group. In addition, another electrode is provided between each of the electrodes, and the electrode group has the above and π
A high frequency voltage with a phase difference of /2 is applied.

As a result, a traveling wave is formed in the elastic body 5, and the rotating disk 6 that is in pressure contact with the elastic body 5 rotates. The direction of rotation of the rotating body 6 changes depending on whether the phase is delayed or advanced. The high frequency voltage J is usually set to a frequency in the ultrasonic range of about 40 to 11 z.

The operation of the above configuration will be explained. When the rotary disk 6 of the piezoelectric drive device 15 rotates the navels I to 8 in forward and reverse directions, the pin shaft 7 supported by the support member 12 so as to move forward and backward moves forward and backward, and the valve body 10 opens and closes the opening 11.

The flow rate can be adjusted by its opening degree.

When the valve body 10 is pushed into the valve seat 11a of the opening 11, it becomes fully closed, and the pressure force is applied from the rotary disk 6 via the feed screw mechanism 16. Therefore, a strong pressing force can be obtained with a small torque of the rotating disk 6, and fluid such as gas can be completely shut off without leakage.

This control valve can be configured compactly because the piezoelectric drive device 15 serving as the drive source is housed within the tubular valve body l. Furthermore, since the piezoelectric drive device 15 is used, the response is better than that using a conventional ribomotor or the like.

〔Effect of the invention〕

Since the control valve of this invention drives the valve body through a feed screw mechanism, the valve body can be strongly pressed against the valve seat with a small torque, and fluids such as gas can be completely shut off. . Furthermore, since a piezoelectric drive device is used that excites an elastic body using a piezoelectric element and drives a rotating disk, the piezoelectric drive device can be housed within the valve body, making the entire valve compact.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of an embodiment of the present invention, Fig. 2 is a cross-sectional view of its partial side, Fig. 3 is a cross-sectional view of a conventional example, Fig. 4 is an explanatory diagram of its operation, and Fig. 5 is another conventional example. FIG. 1... Valve body, 2... Partition wall, 4... Piezoelectric element, 5
... Elastic body, 6... Rotating disk, 7... Helical shaft, 8
... Nut, 10 ... Valve body, 11 ... Opening, 15
...Piezoelectric drive device, 16...Feed screw mechanism 3V Fig. 3ba Fig. 2 Fig. 5

Claims (1)

[Claims] A valve body is provided that faces the valve seat of the valve body and moves toward and away from the valve seat, and a feed screw mechanism is provided that includes a screw shaft with the valve body attached to the tip and a nut that is screwed onto the screw shaft, and the nut is rotated. A piezoelectric drive device is provided, and the piezoelectric drive device includes a ring-shaped rotating disk to which the nut is attached, an elastic body in contact with the rotating disk, and exciting this elastic body to rotate the rotating disk. A control valve consisting of a piezoelectric element.