Pilot-operated pressure regulating valve

Abstract

A pilot-operated pressure regulating valve for fluid inflow and / or outflow from a fluid working device comprises: an output connected to the fluid working device; an input through which fluid flows into the pressure regulating valve; an outflow connection from the output to a pressure drop portion through which fluid flows from the working device; an outflow valve seat that opens and / or closes the outflow connection; an inflow connection between the input and output ends; an inflow valve seat that opens and / or closes the inflow connection; a switching piston configured to be switchable between a first and a second position, and an actuating device for switching the switching piston from the first to the second position. In the first position, the switching piston releases the outflow valve seat and closes the inflow valve seat when not in contact with the actuating device, and in the second position, closes the outflow valve seat and releases the inflow valve seat. The outflow connection extends at least partially within the switching piston, and the inflow connection extends at least partially outside the switching piston, coaxially with respect to the outflow connection.

Description

Technical Field

[0001] The present invention relates to a pilot-operated pressure regulating valve for the inflow and / or outflow of fluid in a fluid working device. Background Art

[0002] Such pilot-operated pressure regulating valves are well known in the prior art. Publication DE 10 2016 100919 discloses a pneumatic volume flow amplifier for amplifying a pneumatic control pressure output signal of a position controller. The pneumatic volume flow amplifier ventilates and / or exhausts pneumatic drives, such as pneumatic control drives, for actuating control accessories (e.g., control valves), process technology equipment (e.g., petrochemical equipment), food processing equipment (e.g., brewing machines), and the like. A pneumatic control output is provided for connection to a pneumatic working chamber of a pneumatic drive mechanism; a first pneumatic ventilation input, in particular for receiving a pneumatic regulating pressure output signal of a position regulator; at least one pneumatic amplification input, in particular for receiving a pneumatic air amplification signal, in particular a constant signal, such as a supercharger; a pneumatic exhaust connection from the control output to a pressure drop portion for exhausting the regulating drive mechanism; an exhaust seat valve for separating and / or opening the pneumatic exhaust connection; a pneumatic ventilation connection between the first ventilation input and the control output; a ventilation seat valve for separating and / or opening the pneumatic ventilation connection; a pneumatic amplification connection between the amplification input and the control output; a amplification seat valve for separating and / or opening the pneumatic amplification connection; and a mechanical seat valve-operating portion for jointly operating the exhaust seat valve, the first ventilation seat valve and the amplification seat valve.

[0003] The pressure regulating valves known in the prior art have the disadvantage that they are usually complex to manufacture and that a plurality of sealing elements must be installed for pressure compensation. The sealing elements are subject to friction and wear and can become contaminated. Summary of the Invention

[0004] Therefore, an object of the present invention is to provide an improved pilot-operated pressure regulating valve to overcome at least one disadvantage of the prior art.

[0005] According to the invention, this object is achieved by the subject-matter of claim 1 .

[0006] Advantageous and expedient embodiments of the actuator according to the invention are specified in the dependent claims.

[0007] The present invention is based on the concept of a pilot-operated pressure-regulating valve for the inflow and / or outflow of fluid from a fluid-working device, comprising an outlet for connection to the fluid-working device, an inlet for the inflow of fluid into the pressure-regulating valve, and an outflow connection from the outlet to a pressure drop portion for the outflow of fluid from the working device. Furthermore, the pressure-regulating valve comprises an outflow valve seat for opening and / or closing the outflow connection, an inflow connection between the inflow and the outlet of the pressure-regulating valve, an inflow valve seat for opening and / or closing the inflow connection, a switching piston switchable between a first position and a second position, and an actuating device for switching the switching piston from the first position to the second position. In the first position, the switching piston releases the outflow valve seat and closes the inflow valve seat in a non-contact state with the actuating device, while in the second position, the switching piston closes the outflow valve seat and releases the inflow valve seat. The outflow connection extends at least partially within the switching piston, and the inflow connection extends at least partially outside the switching piston, coaxially with respect to the outflow connection. The outflow valve seat and the inflow valve seat are arranged spaced apart from each other in the flow direction (D) of the switching piston, and the cross section of the outflow valve seat and the cross section of the inflow valve seat have approximately the same diameter in the flow direction (D).

[0008] The advantage of the pressure-regulating valve according to the present invention is that only one sealing element is required for pressure compensation. Overall, the pressure-regulating valve thus exhibits less friction and wear. Furthermore, the requirements for the precision and performance of the guide fitting are reduced. This, for example, reduces manufacturing costs. Another advantage is that the spatial separation of the valve seats reduces the risk of leakage due to entrained dirt or foreign matter.

[0009] According to a preferred embodiment, the switching piston comprises an inlet valve seat element and an outlet valve seat element, which, in longitudinal cross-section, are each configured in the shape of a T. This results, for example, in a technical advantage that the switching piston and the pressure regulating valve can be manufactured more simply overall and that reduced tolerance requirements are imposed.

[0010] In another advantageous embodiment, the inlet valve seat element includes a receptacle for a section of the outlet valve seat element. This provides the technical advantage that the inlet and outlet valve seat elements can be easily assembled to form the switching piston. This simplifies assembly of the switching piston and the entire pressure regulating valve.

[0011] In order to additionally facilitate assembly and to achieve a particularly compact and functionally efficient design of the switching piston, the receptacle is arranged radially within the sealing element of the inflow valve seat element.

[0012] According to an additional embodiment, a first compression spring rests against the inlet valve seat element, and when the switching piston is switched to the second position, its force acts in the opposite direction to the switching motion. This provides several technical advantages. For example, the switching piston can always be mechanically switched back to the first position by means of the compression spring. Furthermore, the compression spring fulfills important safety requirements. Even in the event of a power failure, the switching piston returns to the first position. In conjunction with the actuating device, the outflow and inlet valve seats are sealed.

[0013] To achieve the most leak-free possible sealing of the outflow valve seat, the actuating device includes a sealing element designed to close the outflow valve seat. This ensures sealing of the outflow valve seat even with minimal force. For this purpose, the sealing element is designed to be flat and arranged in a receptacle of the actuating device. This sealing element is functionally efficient and inexpensive to manufacture.

[0014] According to a particular embodiment, the pressure regulating valve includes a guide element that laterally guides the switching piston when switching between the first and second positions. This provides the technical advantage of precisely guiding the switching piston regardless of its position. This prevents tilting or skewing of the switching piston, and reduces the requirements for fit accuracy and performance. This also reduces manufacturing costs, for example. Furthermore, a second compression spring is arranged between the actuating device and the guide element. Its pressure acts mechanically in opposition to the actuating device.

[0015] According to a particularly preferred embodiment, the flow cross section of the outflow valve seat element decreases at least in sections, starting from the outflow valve seat in the direction of the inflow valve seat. This achieves the technical advantage, for example, that the cross section of the outflow valve seat and the cross section of the inflow valve seat can have approximately the same diameter in the throughflow direction (D). On this basis, the reduction in the flow cross section is designed to be continuous. This enables a particularly laminar flow without turbulence, which could be generated, for example, by a step-like reduction in cross section.

[0016] In order to switch the pressure regulating valve in the operationally ready mode, the operating device closes the outflow valve seat and the inflow valve seat in a state abutting against the switching piston arranged in the first position. No fluid flow occurs here, and both valve seats are closed.

[0017] In order to achieve the longest possible service life of the pressure regulating valve, the inlet valve seat element and the outlet valve seat element are made of a metal material. In particular, by using sealing elements made of rubber-like plastic, respectively assigned to the inlet valve seat element and the outlet valve seat element, in addition to a long service life, a reliable seal without leakage is obtained.

[0018] According to a special embodiment, the actuating device is configured as a fluid-actuated diaphragm valve. A diaphragm valve known from the prior art can be used, thereby enabling cost-effective production of the pressure regulating valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Exemplary embodiments of the invention are shown in the drawings and are described in detail below.

[0020] In the figure:

[0021] Figure 1 shows a schematic longitudinal sectional view of a pressure regulating valve according to the present invention in a first embodiment;

[0022] Figure 2 The pressure regulating valve according to the present invention is shown Figure 1 Cross-sectional view of section AA. DETAILED DESCRIPTION

[0023] Figure 1A schematic longitudinal sectional view of a pressure regulating valve 100 according to the present invention in a first embodiment is shown. The pressure regulating valve 100 comprises a housing 200 having an input end 102, through which a fluid (e.g. air) can flow into the pressure regulating valve 100. Alternatively, however, other fluids, such as, for example, a gas mixture, can also flow into the pressure regulating valve 100. In addition, the pressure regulating valve 100 comprises an output end 104 for connection to a fluid working device. The fluid working device can, for example, be a pneumatic drive mechanism. Via the outflow connection 106, the fluid can flow from the input end 102 or from the output end 104 to the pressure drop portion 108 and out of the working device. To this end, the outflow valve seat 110 must be opened. In addition, the pressure regulating valve 100 comprises an inflow connection 112, which is arranged between the input end 102 and the output end 104 of the pressure regulating valve 100. The inlet valve seat 114 serves to open or close the inlet connection 112. The inlet valve seat 114 is opened or closed by a switching piston 120, which is switchable between a first position and a second position. The switching piston 120 is switched by an actuating device 130 in the form of a fluidically actuated diaphragm valve. When the switching piston 120 and the actuating device 130 are in a non-contacting state, the outlet valve seat 110 is released and the inlet valve seat 114 is closed. This state can occur, for example, when an overpressure builds up inside the pressure regulating valve 100. This overpressure pushes the actuating device 130 upward, thereby lifting the sealing element 110 from the outlet valve seat 110. The overpressure can thus be reduced by allowing the fluid to flow out via the outflow connection 106 in the direction of the pressure drop 108. If the actuating device 130 now closes the outflow valve seat 110 and switches the switching piston 120 by force into the second position against the first compression spring 144 , the inflow valve seat 114 is released, whereby fluid flows from the inlet 102 into the outlet 104 to operate the working device.

[0024] The outflow connection 106 is located partially inside the switching piston 120, and the inflow connection 112 extends at least partially coaxially outside the outflow connection 106 outside the switching piston 120. Therefore, the inflow connection 112 and the outflow connection 106 extend partially parallel to each other.

[0025] The switching piston 120 includes an inlet valve seat member 140 and an outlet valve seat member 150. The inlet valve seat member 140 and the outlet valve seat member 150 are made of a metal material such as stainless steel or aluminum.

[0026] Inlet valve seat element 140 and outlet valve seat element 150 are T-shaped or tulip-shaped in longitudinal cross-section. Inlet valve seat element 140 has a receptacle 142 for accommodating a section 152 of outlet valve seat element 150. Receptacle 142 is arranged radially within a further sealing element 148 that is functionally associated with inlet valve seat element 140.

[0027] The outflow valve seat 110 and the inflow valve seat 114 are arranged spaced apart from each other in the longitudinal direction of the switching piston 120. The outflow valve seat 110 is located above the inflow valve seat 114, with the cross-section 111 of the outflow valve seat 110 and the cross-section 115 of the inflow valve seat 114 essentially having approximately the same diameter in the flow direction (D). As a result, only one sealing element is required for pressure compensation. This reduces friction and wear. This, in turn, reduces the requirements for the precision and performance of the guide fitting. Furthermore, the spatial separation of the outflow valve seat 110 and the inflow valve seat 114 reduces the risk of leakage, as entrained dirt or foreign matter cannot simultaneously block both valve seats.

[0028] The actuating device 130, designed as a diaphragm valve, includes a flat sealing element 132, which is held in a receptacle 134 of the actuating device 130. By applying the flat sealing element 132 to the outflow valve seat 110, the outflow connection 106 is sealed. The flow cross section of the outflow valve seat element 150 decreases continuously in an upper section, starting from the outflow valve seat 110 in the direction of the inflow valve seat 114. The reduction in the flow cross section in the upper section gives the outflow valve seat element 150 a tulip-shaped appearance in longitudinal cross-section. The switching piston 120 is guided laterally by a guide element 146, and the second compression spring 136 is supported on the guide element 146 relative to the actuating device 130.

[0029] Figure 2 The pressure regulating valve 100 according to the present invention is shown. Figure 1The housing 200 includes an inlet 102 for the flow of fluid into the pressure regulating valve 100 and an outlet 104 for connection to a fluid-operated device. A cross-section of the switching piston 120 can be seen in the center of the housing 200, through which the outflow connection 106 extends. The switching piston 120 is surrounded by a guide element 146, which laterally guides the switching piston 120 when switching between the first and second positions. This prevents the switching piston 120 from tilting laterally. The guide element 146 includes a total of four radially oriented guide fingers 154, each of which rests on the switching piston 120 for guidance. The number of guide fingers 154 can also be two, three, or more, for example. The second compression spring 136 rests on the guide element 146 outside the switching piston 120 and, through its spring force, presses the actuating device 130 away from the guide element 146.

[0030] All features explained and illustrated in conjunction with the individual embodiments of the invention may be provided in various combinations within the subject matter of the invention in order to simultaneously achieve their advantageous effects.

[0031] The scope of protection of the present invention is given by the claims and is not limited by the features described in the description or shown in the drawings.

[0032] Reference Signs List

[0033] 100 Pilot-operated control valve

[0034] 102 Input

[0035] 104 output terminal

[0036] 106 Outflow connection

[0037] 108 pressure drop part

[0038] 110 Outflow valve seat

[0039] 112 Inflow connection

[0040] 114 Inflow valve seat

[0041] 120 switch piston

[0042] 130 Controls

[0043] 132 Sealing element

[0044] 134 Accommodation

[0045] 136 Second pressure spring

[0046] 140 Inflow valve seat element

[0047] 142 Accommodation

[0048] 144 First pressure spring

[0049] 146 Guide element

[0050] 148 Sealing element

[0051] 150 Outflow valve seat element

[0052] 152 sections

[0053] 154 Guide Finger

[0054] 200 shell

Claims

1. A pilot-operated pressure regulating valve (100) for the inflow and / or outflow of a fluid in a fluid working device, comprising: - an output port (104) for connection to a fluid working device, - an input (102) for the inflow of fluid into the pressure regulating valve (100), - an outflow connection (106) for the outflow of fluid from the working device from the output end (104) to a pressure drop (108), - an outflow valve seat (110) for opening and / or closing the outflow connection (106), - an inflow connection (112) between the input (102) and the output (104) of the pressure regulating valve (100), - an inlet valve seat (114) for opening and / or closing the inlet connection (112), - a switch piston (120) configured to be switchable between a first position and a second position, and - an actuating device (130) for switching the switching piston (120) from the first position into the second position, wherein The switching piston (120) releases the outflow valve seat (110) and closes the inflow valve seat (114) in a first position without contact with the actuating device (130), and closes the outflow valve seat (110) and releases the inflow valve seat (114) in a second position. wherein the outflow connection (106) extends at least partially inside the switching piston (120), and the inflow connection (112) extends at least partially outside the switching piston (120) coaxially with respect to the outflow connection (106), and The outflow valve seat (110) and the inflow valve seat (114) are arranged to be spaced apart from each other in the flow direction (D) of the switching piston (120), and the cross section (111) of the outflow valve seat (110) and the cross section (115) of the inflow valve seat (114) have approximately the same diameter in the flow direction (D).

2. The pressure regulating valve (100) according to claim 1, characterized in that The switching piston (120) comprises an inlet valve seat element (140) and an outlet valve seat element (150), which are each designed in a T-shape in a longitudinal cross-sectional view.

3. The pressure regulating valve (100) according to claim 2, characterized in that: The inlet valve seat element (140) comprises a receptacle (142) for a section (152) of the outlet valve seat element (150).

4. The pressure regulating valve (100) according to claim 3, characterized in that The receptacle (142) is arranged radially within the sealing element (148) of the inlet valve seat element (140).

5. The pressure regulating valve (100) according to claim 2, characterized in that A first compression spring (144) bears against the inlet valve seat element (140), the force of which acts counter to the switching movement when the switching piston (120) is switched into the second position.

6. The pressure regulating valve (100) according to any one of the preceding claims, characterized in that The actuating device (130) comprises a sealing element (132) which is designed to close the outflow valve seat (110).

7. The pressure regulating valve (100) according to claim 6, characterized in that The sealing element (132) is flat and is arranged in a receptacle (134) of the actuating device (130).

8. The pressure regulating valve (100) according to any one of claims 1 to 5, characterized in that: The pressure regulating valve (100) has a guide element (146) which laterally guides the switching piston (120) when switching between a first position and a second position.

9. The pressure regulating valve (100) according to claim 8, characterized in that A second compression spring (136) is arranged between the actuating device (130) and the guide element (146).

10. The pressure regulating valve (100) according to claim 2, characterized in that The flow cross section of the outflow valve seat element (150) decreases at least in sections starting from the outflow valve seat (110) in the direction of the inflow valve seat (114).

11. The pressure regulating valve (100) according to claim 10, characterized in that The reduction in the through-flow cross section is designed to be continuous.

12. The pressure regulating valve (100) according to any one of claims 1 to 5, characterized in that: The actuating device (130) closes the outflow valve seat (110) and the inflow valve seat (114) when it is in contact with the switching piston (120) arranged in the first position.

13. The pressure regulating valve (100) according to claim 2, characterized in that The inflow valve seat element (140) and the outflow valve seat element (150) are made of metal material.

14. The pressure regulating valve (100) according to any one of claims 1 to 5, characterized in that: The actuating device (130) is designed as a fluid-actuable diaphragm valve.

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