DK143208B - PRESSURE MEDIA PRESSURE CONTROLLER - Google Patents

Description

(<f§3>

In ass

(11) PUBLICATION NOTICE 1 ^ 3208 DENMARK (51) Int. Cl.3 F 16 K 31/363 § (21) Application No. 2735/75 (22) Filed on 17 · jUfl. 19'5 (24) Life Day 17 · <Jun. 1975 (44) The application presented and the petition published on 20 July. 1981

DIRECTORATE OF

PATENT AND TRADEMARKET SYSTEM (30) Priori, et ^

Jun 21 1974, 5164/74, AT

(41) Altn. tllg. Dec 22 1975 (71) HOERBIGER FLUIDTECHNIK KG, Vienna IV, Prinz Eugen-Strasse 70, AT.

<72) Inventor: Rudolf Huber, Engerthstrasse 41/27, A-1200 Vienna, AT.

(74) Plenipotentiary 'Case':

International Patent Office.

(54) Pressure regulator for streaming media.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a pressure regulator for flowing media having a control valve whose shutter body is controlled by an adjusting drive which is constituted by a regulating piston or diaphragm and which is actuated in the control valve's opening direction by the throttle position and in the closing direction of the exit pressure where connected chambers over the adjustment drive are connected via a spring loaded self-acting throttle valve with a relief opening.

In the case of pressure regulators of this construction, as is well known, the control characteristic changes depending on the flow rate, ie. that the output pressure is lowered in particular due to the flow resistance of the control valve, with increasing flow rate below the set desired pressure. To prevent this, it is known to use a so-called quantity compensation. It consists in the known embodiments in that the pressure acting on the control valve in the closing direction under the adjusting drive decreases with increasing flow rate. For this purpose, the chamber lying below the actuator is closed and connected to the output side of the regulator only by a conduit which exits from a site of high flow velocity, and thus imparts a reduced static pressure to the underside of the actuator, thereby increasing the output pressure accordingly. However, this arrangement has the disadvantage that the compensation is only effective at high flow rates as the static pressure decreases with the square of the velocity. In order to mitigate this disadvantage, it is also known to narrow or design as a venturisation the site at which the static pressure is taken. However, in this way, the maximum possible amount that can be controlled by the regulator is greatly reduced.

The invention aims to provide a simple amount compensation which does not require a narrowing of the flow-through cross-section of the regulator, which is effective over a wide range of control and can easily be influenced or, in its characteristics, be adapted to the relevant conditions.

This is achieved according to the invention with a pressure regulator of the type mentioned in the beginning, characterized in that between the adjusting drive and the spring-loaded control body of the throttle valve there is a compensation spring which acts on the control body in its opening direction. The compensation spring is supported on the movable adjusting drive and partially cancels the closing force acting on the throttle valve control body. With the closed control valve, the adjusting drive is in its upper position, where the power of the compensation spring is greatest. Thereby, a certain control pressure is adjusted in the chamber above the adjusting drive, the size of which is determined by the difference between the forces exerted by the throttle valve closing springs and the compensation spring. When regulating friend-. while the opening is shifted downwardly the adjustment drive, thereby reducing the force of the compensation spring. This results in an increase in the control pressure in the chamber over the adjusting drive, thereby increasing the output pressure of the pressure regulator. In this way, a quantity compensation is obtained in a simple manner so that the control characteristic of the pressure regulator according to the invention is largely independent of the flow rate.

3

14320G

The degree of compensation obtained by the measures of the invention can be affected as needed by incorporating compensation springs with different characteristics.

When a coil spring is used for linear characteristics, a substantially linear characteristic of the quantity compensation is obtained over the total control range. According to the invention, the compensation spring can have a non-linear characteristic, so that the compensation is more effective at small amounts than at large quantities.

In a further embodiment of the invention, the chamber under which the setting pressure operates is connected only to the output of the flowing medium via a channel which proceeds from a cross-sectional narrowing in the flow path of the regulator on the output side. Quantity compensation can thereby simply be adapted to all conditions.

The invention will be explained in more detail below by means of exemplary embodiments of a pressure regulator according to the invention and with reference to the drawing, in which fig. 1 shows an axial section through an example of a pressure regulator according to the invention, and FIG. 2 shows the same of another example of a pressure regulator according to the invention.

In both of the illustrated examples, the pressure regulator consists of a housing 1 which has an input 2 for supplying the pressure medium and an output 3 for discharge of the controlled medium. Inside the housing 1, there is a control valve between the input 2 and the output 3, which consists of a valve seat 4 and a shutter body 5. The lower end of the shutter body 5 is sealed down into a cylinder bore 6, which is via a channel 7 in the shutter body 5. connected to the pressure regulator output. In this way, a pressure equalization of the regulator valve is achieved. At the upper end, the shutter body 5 passes through a piston rod 8 in conjunction with a regulating piston 9 which constitutes an adjusting drive for controlling the control valve. The control piston 9 is sealed in a cylindrical manner and divides it into an upper chamber 10 and a lower chamber 11. The upper chamber is closed by a cover 12 and is connected via a conduit 15 in which a throttle member 14 is incorporated. connection to the inlet 2. Furthermore, in the cover 12 is a self-acting throttle valve 15, the control body 16 being loaded by a closing spring 17, the bias of which can be adjusted by a hand wheel 18. The throttle valve 15 controls the connection between the upper chamber 10 and a relief opening 19 which is extended out of the side of cover 12. Finally, in the upper chamber 10 is provided a compensation spring 20, which rests on the control piston 9, which acts via a pressure piece 21 on the throttle valve 15's control body 16 in the valve opening direction. .

In pressureless mode, the pressure regulator valve is closed and the shutter body 5 rests against the valve seat 4. When a pressure medium is supplied through the input 2, this first affects via the conduit 13 and the throttle member 14 the upper side of the control piston 9. The throttle valve 15 is also closed, upper chamber 10 a control pressure which, via the piston rod 8, lifts the closing body 5 away from the valve seat 4. Pressure medium can now flow from the inlet 2 through the control valve to the output 3. The pressure, which is now built up on the outlet side, acts in the lower chamber 11 on the underside of the the control piston 9 and maintains equilibrium with the pressure in the upper chamber 10. The control pressure in the upper chamber 10 is regulated by the throttle valve 15 and can be adjusted by the handwheel 18 by changing the bias of the spring 17 as desired. at the input 2, a constant applied pressure of the handwheel 18's dependent pressure at the output 3.

The compensation spring 20 also has the task when the flow rate changes to keep the control characteristic constant. It acts against the spring 17 in the opening direction of the throttle valve control body 16. With the closed control valve as shown in FIG. 1, the regulating piston 9 is in the upper position where the force of the compensation spring 20 is greatest. By contrast, when the control valve is opened and the medium flow from the input 2 is released to the output 3, the control piston 9 is displaced downward and the compensation spring 20 is correspondingly relaxed. As a result, the closing force acting on the guide body 16 is increased and the control pressure in the upper chamber 10 is increased. This results in an even larger opening of the control valve 4, 5 and at the same time a corresponding increase in the output pressure at the output 3. The compensation spring 20 thus compensates for any losses which occur due to flow resistances in the pressure regulator.

In the embodiment of FIG. 2, in addition to the compensating spring 20, other measures have been taken to increase the volume compensation. The chamber 11 under the regulating piston 9 is separated by means of a partition wall 22, in which a channel 23. is built-in. In addition, in the flow direction before the output 3, there is a cross-sectional reduction from which the channel 23 exits. Thereby it is obtained that the pressure due to the pressure drop in the area of this cross-section narrowing is reduced in the lower chamber 11, which also results in an increase in the opening of the control valve and thus a compensation of pressure loss in the flow of larger quantities. Both measures for volume compensation ie. the compensating spring 20 and the cross-sectional constriction 24 reinforce each other so that, even at extremely large flow rates and relatively large flow resistances in the pressure regulator, sufficient compensation is obtained. Furthermore, an adjustment of the compensation degree is possible in a simple manner by selecting the compensation spring 20 and, if necessary, by replacing it.

The compensation spring according to the invention is not only applicable to pressure regulators whose control valve is controlled by means of a control piston, but it is also possible with the same advantage to incorporate the compensation spring by diaphragm-activated control valves. It is also conceivable to supply the pressure medium which builds up the control pressure in the upper chamber from a foreign pressure source instead of via the conduit 13 from the outlet side of the pressure regulator.

Also, variants of the autonomous throttle valve 15 which regulate the control pressure in the chamber 10 are possible within the scope of the invention, and these variants may have suitable embodiments known per se.