DE8717592U1 - Lift valve - Google Patents

Description

Description:

The invention is based on a lift valve with the features specified in the preamble of claim 1. The lift valves used primarily in water pipe systems in buildings have the disadvantage that they suddenly open and close the flow cross-section. The sudden noise that is produced propagates through the water pipe system in the building and is perceived as disturbing.

The short-term pressure increases caused when the valve is closed (called "water hammer") can lead to damage and should therefore be limited; DIN 57 700/Part 600 requires that a pressure of 0.8 MPa must not be exceeded. The short-term pressure increases, called water hammer, can lead to vibrations in the water column in the pipes, which can cause major damage if the resonance frequency is high.

The invention is based on the object of creating a lifting valve that is particularly suitable for use in water supply systems in buildings, which opens and closes quietly, causing neither an excessive short-term pressure drop nor an excessive short-term

causes an increase in pressure.

This object is achieved by a lift valve with the features specified in claim 1. Advantageous further developments of the invention are the subject of the subclaims

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In order to ensure that the force required to open the valve is as small as possible and as independent as possible of the water pressure acting on the closing body, a pressure compensation chamber is preferably provided in the valve, which is located on the side of the closing body facing away from the valve seat and has no connection with the outlet opening of the valve when the valve is closed and is only permanently connected to the inlet opening of the valve via a pressure compensation opening. In this way, there is a pressure equalization chamber on both sides of the closing body.

the same water pressure, and the force to be provided by the motor is primarily determined by the resetting force of the spring on the actuating element for the closing body, which must be overcome. f 15 The pressure equalization reduces the power consumption when

opening the valve. In addition, the valve can therefore i

can be used in water pipe systems with different system pressures without structural changes.

j The pressure compensation hole is preferably cylindrical.

\ 20 derförmig. It has been shown that such a

Pressure compensation hole despite small cross-sectional

j surface hardly gets clogged, but rather self-cleaning is achieved through high flow velocities.

25 In addition to the pressure equalization bore, another opening is provided, which is larger than the pressure equalization bore and connects the pressure equalization chamber with the outlet opening of the valve and through the

, locking body can be closed. If the actuating

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element is raised, the pressure in the pressure compensation chamber drops below the pressure at the inlet opening of the valve, so that the latter _lifts the closing body from the sealing seat without the

The engine would have to do the work.

The invention uses a stepper motor in combination with a gear to drive the actuating element of the lifting valve, which converts the rotary movement of the stepper motor into a linear movement of the actuating element. The electric stepper motor is a pulse-controlled motor, the shaft of which rotates by a constant angle determined by the design with each pulse. The number of pulses then determines the total angle of rotation as an integer multiple of the unit step, and the pulse frequency determines the speed.

Unlike a solenoid valve, in which the opening speed of the closing body is determined by the attraction force of the electromagnet and the closing speed of the closing body is determined by the restoring force of a spring and by the system pressure, in the lifting valve according to the invention the speed of the actuating element and with it the speed of the closing body is limited by the speed of the stepper motor and by the gear ratio and can therefore be easily controlled by selecting a suitable gear ratio and selecting a suitable speed so that neither when opening nor when closing do impacts occur which can be seen as

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disturbing noises are propagated through the pipe network, and that only gentle pressure changes occur when opening and closing. Particular attention should be paid to the possibility of electronically controlling the pulse frequency for actuating the stepper motor in such a way that a movement sequence of the actuating element and the closing body is created that is particularly favorable for low noise. In particular, it is possible to control the temporal progression of the pulse frequency in such a way that the actuating element is moved to its two end positions at a speed tending towards zero. The particularly gentle opening and closing that can be achieved in this way has the further advantage that the flow speed in the pipe is not changed abruptly, but gently, so that noise development due to turbulence and cavitation is largely avoided.

Due to their design, stepper motors are self-locking in their rest positions: their magnetic rotor can only be rotated in its rest positions relative to the stator by overcoming a magnetic restoring moment. The valve according to the invention therefore does not require electrical current to remain in the closed or open state or in intermediate positions, but only to carry out the opening and closing movements. The power consumption of a lifting valve according to the invention is therefore significantly lower than that of a solenoid valve that can be used in its place; this makes it possible to

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to operate the lift valve according to the invention economically using batteries or accumulators. If a valve according to the invention is operated with a rechargeable accumulator in conjunction with a solar array for charging the accumulator, then you can expect a service life of ten years before the accumulator needs to be replaced*

The valve according to the invention is therefore suitable

especially for subsequent installation in water pipe systems: No electrical cable needs to be laid to supply the valve with electricity, and no walls need to be opened to carry out the installation work. In addition, the valve according to the invention is suitable for actuation by means of proximity sensors that respond when an object, in particular a hand, approaches and actuate the stepper motor. Such a sensor can be combined with the valve to form a structural unit and arranged close to a water outlet tap or combined with the water outlet tap to form a structural unit. However, it is also possible to spatially separate the valve and the sensor intended to actuate it, for example to arrange the sensor near a water outlet tap on a washbasin and the valve below the washbasin in the supply line that is already exposed there.

When developing the new valve, particular attention was paid to its use in water pipe systems. However, the valve can also be used in pipes for other liquid or gaseous media.

Cam gears are particularly suitable as gears for the stepper motor. The gear contributes both to the gentle opening and closing of the valve and to the automatic locking of the closing body in its respective position when the valve is stopped, and the force of the gear becomes stronger as the transmission ratio increases.

Cam gears usually have dead center positions. If the end positions of the actuating element for the closing body are placed in the dead center positions of the gear, this also achieves self-locking in the end positions of the actuating element.

A cam mechanism can be implemented by arranging a cam disk on the drive shaft of a transmission gear, the contour of which is scanned by a tappet which is connected to the actuating element of the valve. The tappet can be parallel or at right angles to the output shaft.

of the transmission gear; in the first case, a cam disk is used, one side surface of which is contoured. In the second case, a cam disk is used, the peripheral surface of which is contoured.

&Ggr; 25 at can be achieved simply by selecting the curve P shape,' that at constant engine speed

k the actuating element first slowly and then

opens and closes at an accelerated rate and reaches its "open" end position and its "closed" end position with a speed tending towards zero. Preferably

The curve is formed in such a way that it is
Closing process is steeper than for the opening process. A flatter curve during the opening process
enables the overcoming of a higher counter pressure,
a steeper decline of the curve during the closing process
can reduce water consumption.

Especially when using a cam gear
It is recommended to provide a compression spring, which

acts on the actuating element and turns it into a
its two end positions, conveniently in its
"Closed" end position; the actuator is then moved to the other end position by the
Stepper motor moves against the force of the spring, whereby

the compression spring creates a |(force connection between the actuating element and the cam disc. With j such a compression spring, the easiest way to j

achieve a tight closure of the valve. &iacgr;

I An embodiment of the valve according to the invention |

is shown schematically in the attached drawing. I Figure 1 shows a valve in section. \

The embodiment shown has a 1 conical closing body 7. The closing body 7 can also be a body with other _advantageous geometries.

A screw insert 70 is screwed in, which is

I its end in the housing a ¹ ring-shaped seat I

seal 71 made of rubber presses against a collar surface 72 formed in the housing, with a metal support ring 73, which is preferably made of brass, being located between the seat seal 71 and the screw insert 70. In the screw insert 70 there is a bore 74 leading outwards, into which a bushing 75 is inserted so as to be longitudinally displaceable, into the end of which lying in the housing a support ring 76 is inserted and then the closing body 7 in the form of a rubber cone is vulcanized on. When the valve is closed, the conical surface of the closing body 7 rests against the edge 4 of the seat seal 71, which otherwise serves as a seat for the closing body. The closing body 7 is drilled coaxially to the bushing 75, a tappet 9 is arranged in this bore, which continues into the bushing 75 and lies with its rear rounded end outside the bushing 75. Where the end of the tappet 9 located inside the housing 1 emerges from the closing body 7, the latter is provided with a recess 77 concentrically surrounding the tappet 9, the edge 7b of which serves as a pilot seat for an actuating element 8 with a conical sealing surface attached to the end of the tappet. A ring of 6 to 8 pressure equalization holes 78, which are connected to the outlet opening 3 of the valve, open into the recess 77.

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Inside the bushing 75, a shoulder 9a is formed on the tappet; between the shoulder 9a and the support ring 76 there is a compression spring 13 which tries to press the actuating element 8 against the pilot seat 7b.

For sealing the screw insert 70 against the housing 1 and against the bushing 75 as well as for sealing the bushing 75 against the tappet 9, endless pressed round sealing rings with a circular cross-section 79, 80 and 81 are provided.

On the outside of the screw insert 70 there are blind holes 82 for attaching a drive unit with stepper motor and gear, of which the only part shown is a cam disk 83 sitting on the output shaft of the gear, which permanently acts on the rear end of the tappet.

Figure 1 shows the valve in its closed position. By turning the cam disc 83, the tappet 9 is pushed deeper into the valve in a first phase, so that the actuating element 8 is lifted from the pilot seat 7b. This allows the fluid present on one side to flow into the recess 77 and through the pressure equalization holes 78, whereby the pressure in the closing body 7 is relieved. In a second phase of the opening

The inclined surface of the cam disc 83 acts

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also on the bushing 75 and moves it so that the closing body 7 lifts off a seat 4. The valve is closed by a further rotation of the cam disk 83, as a result of which the compression spring 13 pushes the tappet 9 outwards again so that the pressure compensation holes 78 are closed. When this has happened, the closing body 7 is pressed against its seat 4 by the predominant pressure of the fluid on one side.

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Claims (5)

Fax: 07231/10 11 03.02.1989 V/Wa A. Steudler GmbH & Co. KG,, 7530 Pforzheim Hänsä netäiiwefke AG., 7GGG atüttgaf teriühringeii Hub - Ventil Protection claims: 1. Lift valve, especially for use in water- water supply systems in buildings, with a housing, in which a valve seat and a j 5 closing bodies are provided, which cooperate with the valve seat and are therefore under the influence of a motor-driven, linearly movable actuating element, characterized in that the closing body (7) has a conical sealing surface and is attached to the end of a longitudinally displaceable bush (75) which is led out of the housing (1), that a plunger (9) is mounted in the bushing (75) so as to be longitudinally displaceable, which plunger is guided through the closing body (7) and carries the actuating element (8) at its protruding end, that at least one pressure compensation bore (78) is provided in the closing body (7), which on the one hand is connected to the outlet opening (3) and ·« ti ti J ₄ on the other hand, it can be closed by the actuating element (8), which is pressed against the closing body (7) by a compression spring (13) acting between the tappet (9) and the closing body (7). and that the plunger (9) and the bushing (75) are displaceable one after the other. 2. Valve according to claim 1, characterized in that the motor is an electric stepper motor and that a gear (20) is provided between the stepper motor and the actuating element (8), which converts the rotary movement of the stepper motor into the linear movement of the closing body (1) and the actuating element (8). 3. Valve according to claim 1 or 2, characterized in that a cam disc (83), the shape of the curve being selected such that the cam disc (83) opens or closes the actuating element (8) of the valve initially slowly and then accelerates and with a tendency towards zero speed its "Qffen" end position or its "Closed" end position is reached, whereby the cam disc preferably has a constant speed. 4. Valve according to claim 3, characterized in that the curve provided for the closing process is steeper than the curve provided for the opening process. 5 5. Valve according to claim 3, characterized in that the curve shape provided for the opening process is adapted to the opening cross-sections in the flow path in such a way that the volume flow depends essentially linearly on the stroke of the actuating element (8).