The present disclosure relates to proportional pressure controllers adapted for use in pneumatic systems.
This section provides background information related to the present disclosure which is not necessarily prior art.
Proportional pressure controllers often include main internal valves which are moved to permit a pressurized fluid to be discharged to an actuation device while controlling the operating pressure of the fluid at the actuation device. The main valves are commonly repositioned using solenoids operators. This configuration increases weight and expense of the controller, and requires significant electrical current to reposition the main valves.
Known proportional pressure controllers are also often susceptible to system pressure undershoot or overshoot, wherein due to the mass and operating time of the main valves, the signal to reduce or stop pressurized fluid flow to the actuation device may occur too soon or too late to avoid either not reaching or exceeding the desired operating pressure. When this occurs, the control system operating the solenoid actuators begins a rapid opening and closing sequence as the controller “hunts” for the desired operating pressure. This rapid operation is known as “motor-boating” and further increases controller wear and cost of operation.
This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
According to several embodiments, a proportional pressure controller includes: a controller assembly including a body having inlet, outlet, and exhaust ports; a fill valve is in communication with a pressurized fluid in the inlet port; a dump valve is in communication with the pressurized fluid in a discharge passage of the fill valve; and an inlet poppet valve and an exhaust poppet valve. An outlet flow passage is in communication with the pressurized fluid when the inlet poppet valve is moved to an inlet poppet valve open position. The outlet flow passage communicates with the outlet port and an exhaust/outlet common passage normally isolated from the exhaust port when the exhaust poppet valve is in an exhaust poppet valve closed position. A fill inlet passage provides fluid communication between the inlet passage and the fill valve, and is isolated from each of the outlet flow passage, the exhaust/outlet common passage, and the outlet and exhaust ports in all operating conditions of the controller. The fill inlet passage communicates with the inlet passage and being continuously pressurized by the pressurized fluid in the inlet passage. A pressure sensor is positioned in the discharge passage to isolate the pressure sensor from fluid in the outlet port.
According to additional embodiments, a proportional pressure controller includes a controller body including: inlet, outlet, and exhaust ports; an inlet passage and an outlet passage, the inlet passage communicating a flow of pressurized fluid from the inlet port to the outlet passage, and the outlet passage communicating the flow of pressurized fluid from the inlet passage to the outlet port; and a piston slidably disposed in the controller body. A receiving passage is isolated from any of the inlet and outlet passages and the inlet, outlet, and exhaust ports in each of an open, a closed, and an exhaust operating condition of the controller. The receiving passage fluidly connects to a chamber upstream of the piston and to an exhaust valve pressurization chamber. A slidably disposed inlet poppet valve is adapted to isolate the outlet passage from the inlet passage in an inlet poppet valve closed position. The inlet poppet valve is normally biased to the inlet poppet valve closed position. A slidably disposed exhaust poppet valve is normally held in an exhaust poppet valve closed position by the pressurized fluid in the exhaust valve pressurization chamber. The exhaust poppet valve adapted to isolate outlet passage from the exhaust port in the exhaust poppet valve closed position.
According to other embodiments, a proportional pressure controller includes a controller assembly having open, closed/pressure achieved, and exhaust controller positions. The controller assembly also includes: a body having inlet, outlet, and exhaust ports and an exhaust/outlet common passage; a fill valve in communication with a pressurized fluid in the inlet port; a dump valve in communication with the pressurized fluid in a discharge passage of the fill valve; and a piston slidably disposed in the body in communication with a piston pressurization chamber and moved in response to the pressurized fluid entering the piston pressurization chamber. An inlet poppet valve contacting the piston is slidably disposed in the body. The inlet poppet valve is normally biased to an inlet poppet valve closed position in the closed controller position. The inlet poppet valve is movable by displacement of the piston to an inlet poppet valve open position defining the open controller position. An exhaust poppet valve is slidably disposed in the body and held in an exhaust poppet valve closed position by the fluid pressure directed through the fill valve acting on an end face of the exhaust poppet valve. The fluid pressure creates a greater force than a force due to pressure in the exhaust/outlet common passage of the body acting on an opposite face of the exhaust poppet valve. The exhaust poppet valve isolates the pressurized fluid from the exhaust port when in the closed position.
According to further embodiments, a proportional pressure controller includes a controller assembly having open, closed/pressure achieved, and exhaust controller conditions. The controller assembly also includes: a body having inlet, outlet, and exhaust ports, and an exhaust/outlet common passage; and a valve system adapted to control flow of a pressurized fluid. An inlet poppet valve is slidably disposed in the body and normally biased to an inlet poppet valve closed position defining the controller closed condition. The inlet poppet valve is movable to an inlet poppet valve open position defining the controller open condition by the pressurized fluid directed through the valve system. An exhaust poppet valve is slidably disposed in the body and held in an exhaust poppet valve closed position by the fluid pressure directed through the valve system into an exhaust valve pressurization chamber. An outlet flow passage is in communication with the pressurized fluid from the inlet port when the inlet poppet valve is moved to the inlet poppet valve open position. The outlet flow passage communicates with the outlet port and the exhaust/outlet common passage is normally isolated from the exhaust port when the exhaust poppet valve is in the exhaust poppet valve closed position. A fill inlet passage provides fluid communication between the inlet passage and the valve system. The fill inlet passage is isolated from each of the outlet flow passage, the exhaust/outlet common passage, and the outlet and exhaust ports in all the operating conditions of the controller. The fill inlet passage communicates with and is continuously pressurized by the pressurized fluid in the inlet passage.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
Example embodiments will now be described more fully with reference to the accompanying drawings.
Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.
The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a”, “an” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
When an element or layer is referred to as being “on”, “engaged to”, “connected to” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to”, “directly connected to” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.
Spatially relative terms, such as “inner,” “outer,” “beneath”, “below”, “lower”, “above”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
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Oppositely directed from valve cavity 42 is an inlet valve stem 43 integrally and axially extending from inlet poppet valve 36 and coaxially aligned with biasing member 40. A free end of inlet valve stem 43 contacts a piston 44. Inlet valve stem 43 is slidably disposed through a first boundary wall 45 before contacting piston 44 to help control an axial alignment of inlet poppet valve 36 to promote a perimeter seal of a poppet seat ring 46 with inlet valve seat 38 in the closed position. Pressurized fluid can free-flow through first boundary wall 45 via at least one hole 47 and/or through the bore that permits passage of inlet valve stem 43. A size and quantity of the at least one hole 47 controls the time required for pressure in outlet flow passage 34 to act on piston 44 (on the left side as viewed in
Piston 44 moves coaxially with the inlet poppet valve 36 in inlet valve closing direction “A” or the inlet valve opening direction “B”. First boundary wall 45 defines a first boundary (a non-pressure boundary) and piston 44 defines a second boundary (a pressure boundary) of a cylinder cavity 50 which slidingly receives piston 44. Piston 44 can move in the inlet valve opening direction “B” until an end 51 of piston 44 contacts first boundary wall 45 (at a right hand facing side of first boundary wall 45 as seen in
An elastic seal member 52 such as an O-ring can be positioned within a slot or circumferential groove 53 created externally about a perimeter of inlet poppet valve 36. Elastic seal member 52 provides a relief capacity for pressurized fluid in valve cavity 42 which will be further described in reference to
Proportional pressure controller 10 can be operated using each of an inlet or fill valve 54 and a dump valve 56 which can be releasably connected to central body portion 22 within controller operator 20. Pressurized fluid such as pressurized air received in inlet port 28 is commonly filtered or purified. Fluid that can back-flow into proportional pressure controller 10 via outlet port 30 and outlet flow passage 34 is potentially contaminated fluid. According to several embodiments, the fill and dump valves 54, 56 are isolated from the potentially contaminated fluid such that only the filtered air or fluid received via inlet port 28 flows through either fill valve 54 or dump valve 56. An inlet flow passage 58 communicates between inlet port 28 and outlet flow passage 34 and is isolated from outlet flow passage 34 by inlet poppet valve 36 which can be normally closed. An air supply port 60 communicates with inlet flow passage 58 and via a fill inlet passage 62 which is isolated from outlet flow passage 34, provides pressurized fluid or air to fill valve 54. A valve discharge passage 64 provides a path for air flowing through fill valve 54 to be directed to an inlet of dump valve 56 and a plurality of different passages.
One of these passages includes a piston pressurization passage 66 which directs air or fluid from valve discharge passage 64 to a piston pressurization chamber 68 created in second end cap 16. Pressurized air or fluid in piston pressurization chamber 68 generates a force acting on a piston end face 70 of piston 44. A surface area of piston end face 70 is larger than a surface area of inlet poppet valve 36 in contact with inlet valve seat 38, therefore, when fill valve 54 opens or continues to open further, the net force created by the pressurized fluid acting on piston end face 70 causes piston 44 to initially move or move further in the inlet valve opening direction “B” and away from inlet valve seat 38. This initially opens or allows a further increased flow in a flow passage between inlet flow passage 58 and outlet flow passage 34 to allow pressurized fluid to exit proportional pressure controller 10 at outlet port 30, defining a controller open condition wherein fluid from inlet flow passage 58 is discharged through outlet port 30 (with no flow through exhaust port 32). This operation will be more fully explained in reference to
A portion of the pressurized fluid discharged through fill valve 54 through valve discharge passage 64 is directed via an exhaust valve pressurization passage 72 created in a connecting wall 74 of central body portion 22 into an exhaust valve pressurization chamber 76. When fill valve 54 is open and dump valve 56 is closed the pressurized air or fluid received in exhaust valve pressurization chamber 76 via exhaust valve pressurization passage 72 acts against an exhaust valve end face 78 of an exhaust poppet valve 80 to retain exhaust poppet valve 80 in a seated position shown.
Exhaust poppet valve 80 includes an exhaust poppet valve seat ring 83 which contacts an exhaust valve seat 84 in the seated position of exhaust poppet valve 80. When exhaust poppet valve 80 is in the seated position shown in
Exhaust poppet valve 80 includes an integrally connected, axially extending exhaust valve stem 90 which is slidingly received in a stem receiving passage 92 of a stem receiving member 94. Stem receiving member 94 is positioned between a second boundary wall 96 and the first end cap 14. Similar to first boundary wall 45, pressurized fluid can free-flow through second boundary wall 96 via at least one hole 97. A size and quantity of the hole(s) 97 controls the speed at which pressure balances across second boundary wall 96. A dump valve passage 98 is provided at a discharge side of dump valve 56 which communicates via a dump valve exhaust port 100 of central body portion 22 with exhaust flow passage 88. It is noted that dump valve outlet passage 98 is isolated from and therefore does not provide fluid communication with exhaust valve pressurization passage 72, valve discharge passage 64, or piston pressurization passage 66.
It is further noted that each of the valve discharge passage 64, piston pressurization passage 66, exhaust valve pressurization passage 72, and dump valve passage 98 are isolated from fluid pressure in outlet flow passage 34 or exhaust/outlet common passage 86 when fill valve 54 is open. These flow passages therefore allow communication of the filtered air or fluid from inlet port 28 to be communicated through either fill or dump valve 54, 56 without exposing the fill or dump valves 54, 56 to potentially contaminated fluid in outlet port 30.
Proportional pressure controller 10 can further include a circuit board 101 positioned within controller operator 20 which is in electrical communication with both fill and dump valves 54, 56. Signals received at circuit board 101 for positioning control of either fill or dump valve 54, 56 are received via a wiring harness 102 in controller operator 20 which is sealed using a connecting plug 104. A remotely positioned control system 106 performs calculation functions and forwards command signals to circuit board 101 which controls either/both fill and/or dump valves 54, 56 to control a system pressure at outlet port 30. Control signals from and to proportional pressure controller 10 and control system 106 are communicated using a control signal interface 108. Control signal interface 108 can be a hard wire (e.g.: wiring harness) connection, a wireless (e.g.: radio frequency or infra red) connection, or the like. The controller closed condition shown in
The configuration shown in
Referring to
First boundary wall 45 can also function as a contact surface stopping the sliding motion of piston 44 in the inlet valve opening direction “B”. A length of time that inlet poppet valve 36 is in the open position can be used together with the pressure sensed by first pressure signaling device 110 to proportionally control the pressure at pressure actuating device 114. Because first pressure signaling device 110 is also positioned within valve discharge passage 64, first pressure signaling device 110 is also isolated form potential contaminants that may be present in outlet port 30. This reduces the possibility of contaminants affecting the pressure signal of first pressure signaling device 110. As previously noted, when pressurized fluid is being discharged through outlet port 30 and when fill valve 54 is in the open position, pressurized fluid from valve discharge passage 64 is received via exhaust valve pressurization passage 72 in exhaust valve pressurization chamber 76 to retain the exhaust poppet valve 80 in its seated position by forcing the exhaust poppet valve 80 in the exhaust valve closing direction “C”.
Referring to
As exhaust poppet valve 80 moves in the exhaust valve opening direction “D”, an exhaust flow ring 116 opens to allow flow in the direction of the multiple flow arrows shown from exhaust/outlet common passage 86 through exhaust flow ring 116, into exhaust flow passage 88, and exiting via exhaust port 32. The signal to open dump valve 56 is also received when the pressure at pressure actuated device 114 exceeds the desired pressure setting. When the desired pressured setting is exceeded, it is advantageous to exhaust the higher fluid pressure via the exhaust port 32 as rapidly as possible. Pressured balanced exhaust poppet valve 80 is therefore opened which allows rapid de-pressurization via exhaust/outlet common passage 86, exhaust flow ring 116, exhaust flow passage 88, and exhaust port 32. With dump valve 56 open, the dump valve outlet passage 98, depressurizing valve discharge passage 64, piston pressurization passage 66, piston pressurization chamber 68, and exhaust valve pressurization passage 72 also depressurize via exhaust port 32.
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Proportional pressure controllers of the present disclosure offer several advantages. By eliminating solenoid actuators associated with the main flow valves of the controller and replacing the valves with poppet valves, small and lower energy consumption pilot valves in the form of fill and dump valves are used to provide pressure actuation to open or close the poppet valves. This reduces the cost and operating power required for the controller. The use of passageways created in the body of the controller to transfer pressurized fluid to actuate the poppet valves which are isolated from the main poppet valve flow paths prevents potentially contaminated fluid at the outlet of the controller from back-flowing into the pilot valves, which could inhibit their operation. One of the passageways can be used to simultaneously provide pressure to open one of the poppet valves while holding the second poppet valve in a closed position. By positioning a pressure sensing device in one of the isolated passageways, the pressure sensing device is also isolated from contaminants to improve the accuracy of the device's pressure signal. Also, the fill and dump valves can be provided in multiple valve forms, including solenoid actuated valves, hydraulically actuated valves, and a 3-way valve replacing both the fill and dump valves.
The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the invention, and all such modifications are intended to be included within the scope of the invention.
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Number | Date | Country | |
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20110179946 A1 | Jul 2011 | US |