FI82761B - Motor-driven valve for controlling a fluid flow - Google Patents

Abstract

In a valve in which the flow of a medium is controlled by rotation of a moveable plate 6, an ultrasound motor is used, so that the rotatable plate 6 directly forms a moveable part of the ultrasound motor. In contact with this part is a vibration element 11, the vibrations of which are produced by piezoelectric elements 12. The vibration element 11 with the piezoelectric elements 12 may be annular in shape, thereby surrounding the medium that flows in a pipe for example. The invention creates an especially compact and simple solution, and the movements of the plate do not require mechanical transmission elements, as is the case, for example, where ordinary electric motors are used. <IMAGE>

Description

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The present invention relates to a fluid-operated, motor-operated valve, in which the movable valve member is a rotating plate, the respective position of which determines the flow opening of the valve.

10 The use of electric motors in valve control has long been known, and in recent years the use of small motors has also become more common in various applications of hot water valves, i.e. faucets. One example that can be mentioned here is, for example, thermostatically controlled shower taps, which can be driven by an electric motor so that only the desired temperature is selected by pressing a button.

One inconvenience in these applications is that the speed of the electric motor is generally relatively high, necessitating expensive and space-consuming transmissions, such as gears, between the motor and the valve member itself. Of course, such mechanical transmissions, in addition to their high cost, are prone to damage over time.

The present invention now aims at a motor-operated valve in which the above-mentioned problems are almost completely eliminated. The solution according to the invention is based on the use of a so-called ultrasonic motor, and in particular still applied in such a way that the valve member directly or at least substantially directly forms a moving part of the ultrasonic motor.

In this context, it may be appropriate to briefly explain a few principles of the ultrasonic motor.

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Perhaps the most common type of ultrasonic motor comprises an annular metallic oscillating stator, the oscillation of which is effected by successive piezoelectric elements 2 82761 fixed to the surface of the ring, to which alternating sine wave voltages of 90 ° phase shift are applied to each other. When another ring or plate is pressed against the vibrating ring, the vibrating ring causes the 5 plates or rings on it to rotate. The intensity of the voltage can be used to control the speed of rotation and, with the phasing of the voltages, the direction of rotation. In most cases, a friction layer is also placed between the vibrating ring and the rotating plate to improve adhesion. Reference is made here to patent application 10 GB-2 120 462.

A slightly modified version of this is such that a ring consisting of Piet electroelectric elements surrounds a metal inner ring which forms a vibrating body and inside which an element to be rotated is still arranged. This is also described in the above-mentioned patent application GB-2 120 462.

Yet another slightly different type is one in which the piezoelectric elements are pressed between two cylindrical (aluminum) pieces, one of which is further pressed against a notched body. The latter, on the other hand, causes the counterpart which rests on the spring to rotate. Reference is made here to EP-example 86 102 249.9 (Publication No. 198 183).

The present invention is now characterized in that the rotating plate or the part directly attached thereto forms a movable counterpart of the ultrasonic motor, which is pressed against the vibrating body subjected to vibration by means of piezoelectric elements.

A preferred embodiment is such that the oscillating body of the ultrasonic motor is annular and is positioned so as to surround the flow of material.

When the rotating plate, together with the fixed plate, is placed inside the pipeline, an oscillating body 11 3 82761 is placed either inside the pipeline next to its wall, or in some cases it can also form part of the wall itself. In the latter cases, the piezoelectric elements must be placed outside the wall of the pipe.

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The invention and its other features and advantages are described in more detail below in the form of examples and with reference to the accompanying drawings, in which Figure 1 shows an embodiment of a valve according to the invention in perspective and partly in section, Figure 2 shows a slightly different embodiment from Figure 1, Figure 3 shows Fig. 4 shows yet another alternative to the embodiment of Fig. 1, and Fig. 5 shows another embodiment of the invention in which the engine is different from Figs. 1-4.

In Fig. 1, reference numeral 1 denotes a cylindrical pipe section which is threadedly connected to another pipe section 2, which is further provided with a shoulder 4 so as to continue as a narrower pipe 3.

Reference numerals 5 and 6 denote two ceramic plates provided with cooperating through holes 8 and 9, of which the plate 5 is fixed and the plate 6 is rotatable so that the size of the through hole of the holes 8 and 9 is determined by the position of the plate 6 , 30 which has already become well known in connection with water fittings.

Reference numeral 7 denotes only a notch which engages the notch of the plate 5, preventing it from rotating.

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The ultrasonic motor in this case consists of the following parts, namely a ring formed by alternating piezoelectric elements 12, an annular oscillating body 11 and a movable part pressed against the latter, in this case a movable plate 6. The ultrasonic motor is connected to an AC The two piezoelectric elements have two phase shifts which are in phase shift with respect to each other, as described in more detail in the publications describing these motors.

The entire valve package, i.e. the piezoelectric elements 12, the oscillating ring 11 and the ceramic plates 5 and 6 are sealed with respect to the tube 1 by an O-ring 10 and with respect to the shoulder 4 by a sealing ring 13.

It is therefore essential in the invention to utilize the ultrasonic motor principle 15 so that the valve member, i.e. the movable plate 6, can directly form a movable part of the motor. Naturally, the same effect is obtained if the moving part is a ring in the normal way, which is then immediately attached to the ceramic plate. Between the oscillating body 11 and the plate 6 of the motion picture 20 there may be, as is known from ultrasonic motors, some layer of friction, not shown in Fig. 1.

Fig. 2 shows in principle a completely similar solution 25 to Fig. 1, only the abutment surface holding the plate assembly together is provided by the depressions 1a of the tube 1, and the fixed plate 5 is sealed at its circumference by an O-ring 10. Otherwise the structure is similar to Fig. 1.

Figure 3 differs from the previous ones in that the oscillating body, i.e. the ring, is implemented as an integral part 11a of the wall of the tube, more specifically the shoulder 4. The piezoelectric elements 12 are arranged in succession in the shape of a ring under the shoulder 4, i.e. outside the tube.

The vibration then has to pass through the wall of the tube, i.e. the shoulder 4 must be thinned on both sides of the vibration ring 11a.

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Fig. 3 also shows the friction layer 15 mentioned above in connection with Fig. 1 between the vibrating body 11a and the moving plate 6.

Figure 4 shows an alternative embodiment in which the piezoelectric elements are formed as a ring 12 outside the pipe 2, surrounding the pipe. The wall of the tube 2 is thinned at the ring 12 so that the wall itself forms a vibrating body 11b. In this case, it may be necessary to thin the tube over a longer distance than just the width of the ring 12 in order to allow the vibrations to pass through the wall and to cause the plate 6 to rotate.

The plate assembly is sealed to the piping by O-rings 10 and 16.

Finally, Figure 5 shows an application using a slightly different type of ultrasonic motor. With regard to the structure of this motor 20, reference is made to the already mentioned European patent application 86 102 249.9, publication number 198 183. The motor comprises piezoelectric elements 12 which are tightly clamped between two cylindrical aluminum pieces 19 and 20. In addition, a vibrating body 11c is pressed against the part 19, which on the one hand comprises a notch 21 and on the other hand a plate-like central part 22, the latter parts being set at different angles to each other. A plate-like body 23 is sprung against the central part 22. Of the plates 5 and 6 forming the valve package, a movable plate 6 is attached directly to the body 23. The vibration of the part 11c causes the body 23 to rotate, while the flow opening formed by the plate combination 5 and 6 varies.

In this case, the valve is placed in the channel 18 formed by the angle of the valve body 35 17 and the package is sealed with respect to the body by O-rings 16 and 24. The opening in the movable plate 6 ends at the edge of the plate.

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It is clear that the embodiments described above can still be varied in many ways within the spirit of the invention and the following claims.

Claims (9)

7 82761 A fluid-operated, motor-driven valve, wherein the movable valve member is a rotating plate (6), the position of which determines the flow opening of the valve, characterized in that the rotating plate (6) or the part (23) directly attached thereto forms an ultrasonic a movable counterpart of the motor, which is pressed against the vibrating body (11; 11a; 11b; 11c) made to vibrate by means of the piezoelectric elements (12). 10 A valve according to claim 1, wherein the oscillating body (11, 11a, 11b) of the ultrasonic motor is annular, characterized in that the annular oscillating body (11, 11a, 11b) is arranged to surround the flow. Valve according to claim 2, wherein the rotating plate (6) together with the fixed plate (5) is arranged in a pipeline (1, 2, 3) with a shoulder-forming extension, characterized in that the vibrating ring body (11) of the ultrasonic motor 11a) is located on the shoulder (4) inside the tube. Valve according to Claim 3, characterized in that the oscillating ring body (11a) is integral with the shoulder (4) and the material thickness of the shoulder is small on both sides of the ring, the piezoelectric elements (12) of the ultrasonic motor being arranged on the shoulder (4). outside the wall. 30 Valve according to claim 2, wherein the rotating plate (6) together with the fixed plate (5) is arranged in the pipeline (1, 2, 3), characterized in that a ring (12) 35 of piezoelectric elements of the ultrasonic motor is arranged around the pipe and (2) the wall forms a vibrating body (11b). β 82761 Valve according to Claim 5, characterized in that the pipe wall (2) is thinned at the vibrating ring. The valve of claim 1, wherein the body of the ultrasonic motor consists of a substantially cylindrical body divided longitudinally into portions (19, 20, 11c) between which the piezoelectric elements (12) are compressed, wherein the end of the body is associated with vibrations of the body. a rotatable part (23), characterized in that the rotating plate (6) of the valve is fixed directly to said rotatable part (23) or forms said part itself. 15 Patentkrav