Precision opening and closing mechanisms for valves

Abstract

The opening and closing mechanism comprises: -Power(1) -Rotation direction setting device (2) - a control unit (3) connected to the rotation direction setting device (2), - a valve actuator motor (5) connected to a control unit, one of the connections sending a BREAK command from the control unit (3) to the motor (5), which is a signal sent when a shutdown occurs due to an over-torque inferred from the motor rotation speed. The switching mechanism is not limited by plug wear, does not require the use of measurements of consumed current, and defines torque levels based on measurements of the motor rotation speed, which corresponds to a predefined nominal torque.

Description

[Technical field]

[0001] The subject of the present invention, as defined by the title, is a precision opening and closing mechanism for valves controlling the supply of different fluids, a particular feature of which is the fact that the precision opening and closing is performed based on the measurement of the motor rotation speed and not on the current consumed.

[0002] The present invention is characterized by its particular design and construction and by the fact that it uses the measurement of the motor rotational speed as a signal to identify whether the valve closing seat has reached its limit switch.

[0003] The invention therefore falls within the field of valve opening / closing control mechanisms on the one hand, and the field of valve actuator protection on the other hand. [Background technology]

[0004] A valve is a movable device that can open or close a circulation path to allow, prevent, or control the flow of a fluid.

[0005] It is extremely important to have precise timing when opening and closing the valve to ensure that the plug is positioned in a manner that will accomplish its intended purpose whether it is opened or closed.

[0006] To date, there are various opening and closing control systems. First, there is the stroke limiter, which is a device that is installed in combination with the valve closing actuator and can determine when the actuator should be shut down because it has reached a limit switch and therefore is deemed to have progressed to open or close the plug.

[0007] These systems that control the opening and closing, and therefore limit the movement of the plug, have the disadvantage that the limit switch does not capture changes due to wear of the actuator or geometric changes of the seat. In other words, the plug always closes in the same place, regardless of its condition, including wear or subsequent structural changes, since the limit switch is not sensitive to possible changes in the plug. This means that over time the plug may wear and require many rotations to close properly, which is difficult as it requires changing the position of the limit switch.

[0008] There are other valve opening and closing control systems that are based on the use of electronic torque limiters for the valve actuator motors.

[0009] The electronic torque limiter is a component that is built into the electrical control board to prevent failures that may be caused by mechanical overstress.

[0010] The function of the torque limiter is to constantly monitor the nominal current consumed by the electric motor and automatically cut off the motor if a predefined value is exceeded.

[0011] If a certain current is exceeded, the torque limiter will be tripped because the nominal current drawn by the motor will exceed a predefined value, and the motor will therefore be electrically disconnected to prevent problems or further damage. The torque limiter can also signal an alarm so that the problem can be resolved before starting again.

[0012] While the torque protection systems used heretofore accomplish their intended purpose, they are complex, require constant measurement of current, and are not as accurate as practicable, subject to fluctuations or changes that may indicate that the protection is not as effective as hoped.

[0013] The object of the present invention is therefore to overcome the above-mentioned drawbacks of valve actuator control methods, in particular the movement of the valve plug, through the development of an opening and closing mechanism that is not limited by plug wear or changes in valve shape and meets the required level of precision. Thus, a precise valve opening and closing mechanism has been developed as described below, the essential elements of which are recited in claim 1. Summary of the Invention [Means for solving the problem]

[0014] BRIEF DESCRIPTION OF THE DRAWINGS The essential elements of the subject matter of the present invention are set forth in the independent claims. Different embodiments are then set forth in the dependent claims.

[0015] The subject of the present invention is a precision opening and closing mechanism for a valve, which comprises: A power supply that is powered from a utility power source providing -24V AC and powers both the valve actuator motor and the other modules of the mechanism. - a direction setting device powered by a power supply, having an opening and closing switch at its inlet and connected at its outlet to a control unit. - A control unit, powered by the power supply, receives a signal from the direction setting device. This control unit is configurable and is responsible for sending and receiving commands from the valve actuator motor and ensuring the proper functioning of the system. It is therefore connected to the motor itself and to the mechanical reducer. -The mechanical reducer is disposed at the motor outlet.

[0016] The connection between the control unit and the valve actuator motor comprises: -Two power connections -On-off connection - Open / close connection - A connection for the motor to inform the control unit of the speed at which it is rotating - A connection for the control unit to notify the motor that a shutdown has occurred due to over-torque as inferred from the motor speed

[0017] The control unit receives and transmits rotation direction information to the motor, as well as transmitting activation of the motor, which will stop at the position indicated by the limit switches contained in the mechanical module.

[0018] When a shutdown occurs due to over-torque inferred from the motor rotation speed, the control unit cuts off the ON signal and sends a BREAK command.

[0019] This mechanism allows torque protection in valve actuator motors without the need to use measurements of consumed current, using a system already in place for the motor to control speed and prescribing torque levels based on measurements of the motor rotation speed. Thus, the rotation speed corresponding to the nominal torque is pre-defined such that in the presence of over-torque the rotation speed is reduced. This allows the presence of over-torque to be inferred, thus making effective, simple and economical torque protection for motors possible, since no wiring is required.

[0020] Unless otherwise indicated, all technical and scientific elements used in this report have the meaning that a person of ordinary skill in the art would normally understand to which the present invention belongs. In the implementation of the present invention, similar or equivalent procedures and materials to those described in the report may be used.

[0021] Throughout the specification and claims, the word "comprises" and variations thereof are not intended to exclude other technical features, additions, components or steps. For those skilled in the art, other objects, advantages and features of the present invention may be inferred partly from the description and partly from the implementation of the present invention. [Brief description of the drawings]

[0022] In order to supplement the description given and to enable a better understanding of the features of the present invention, according to a preferred example of an actual embodiment, attached as an integral part of the description, for illustrative purposes only, is a set of figures represented below.

[0023] [Figure 1] FIG. 1 is a general overview of the connections of modules forming part of a precision opening and closing mechanism for a valve. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] A preferred embodiment of the proposed invention will now be described with reference to the accompanying drawings.

[0025] In FIG. 1 it can be seen that the precision opening and closing mechanism for the valves comprises: - a power supply (1), powered from the mains (6) and responsible for generating a voltage of 24V AC to power the other modules.

[0026] - a direction switch (2) which receives power from the power source (1) by means of a power connection (1.2). The direction switch (2) has at its inlet an on-off switch (7) which is connected to the incoming power phases - a control unit (3) which receives power from the power source (1) by means of a power connection (1.1) and is connected to the direction setting device (2) by means of three connections (2.1). The control unit is configurable and is responsible for sending and receiving commands from the motor as well as ensuring its proper functioning.

[0027] - an actuator motor (5), specifically o Two primary power connections (3.1) o A third connection (3.2) for sending commands from the on-off control unit to the motor (5) o A fourth connection (3.3) for transmitting opening and closing commands from the control unit (3) to the motor (5) o A fifth connection (3.4) for transmitting the rotational rotation of the motor (5) to the control unit o A sixth connection (3.5) for sending a BREAK command from the control unit (3) to the motor (5), which is the signal sent when a shutdown occurs due to an overtorque inferred from the motor speed value. an actuator motor (5) connected to a control unit by - A mechanical reducer (4) mechanically connected to the motor shaft (5).

[0028] Although the nature of the invention, as well as the manner in which it may be practiced, has been fully described, the essential elements of the invention may be embodied in other embodiments having details different from those given in the examples, while still remaining within the scope of protection sought, provided that they do not alter, modify or modify its fundamental principles.

Claims

1. A precision opening and closing mechanism for a valve, - Power supply (1), which is powered by the commercial power supply (6) and is responsible for generating a 24V AC voltage to supply power to other modules. - A rotation direction setting device (2) that receives power from the power supply (1) via a power connection (1.2). The rotation direction setting device (2) has an on / off switch (7) connected to the input power phase at its inlet. - A control unit (3) that receives power from the power supply (1) via a power connection (1.1) and is connected to the rotation direction setter (2). The control unit is configurable and is responsible for sending and receiving commands from the motor (5), and for ensuring its proper function. - Valve actuator motor (5), specifically, o Two primary power connections (3.1) o A third connection (3.2) for transmitting commands from the on-off control unit to the motor (5) o A fourth connection (3.3) for transmitting an open / close command from the control unit (3) to the motor (5) o A fifth connection (3.4) for transmitting the rotation of the motor (5) to the control unit (3). o A sixth connection (3.5) for transmitting a BREAK command, which is a signal transmitted when a stop occurs due to excessive torque estimated from the motor rotation speed, from the control unit (3) to the motor (5). The valve actuator motor (5) is connected to the control unit (3). - A mechanical reducer (4) mechanically connected to the shaft of the motor (5) A precision opening and closing mechanism for valves, equipped with the above.

2. The precision opening and closing mechanism for a valve according to claim 1, characterized in that the control unit (3) is connected to the rotation direction setter (2) by three connections (2.1).

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