JP2005098367A - Positioner and air-flow rate regulating device used therein - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positioner and an air flow rate regulating device for use in it, easily changing the speed of a valve and adjusting the sensitivity. <P>SOLUTION: This positioner 1 includes: a pilot valve 21 for supplying air to a driving part to which a valve is connected through a conduit pipe 71; an operation control part 2 for controlling the operation of the pilot valve 21; and a drive control means 41 for controlling the drive of the driving part. This air flow rate regulating device 31 includes: an air passage 33 to which the conduit pipe 71 is connected; an insert passage 34 formed in the direction of intersecting perpendicularly to the air passage 33; a valve 35 freely movably inserted in the insert passage 34; and a discharge small hole 37 formed in the valve 35 for discharging some of output pressure to the outside. The device 31 is disposed near an output port of the pilot valve 21 in the conduit pipe 71. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a positioner and an air flow rate adjusting device used therefor, and more specifically, a positioner that can be adapted to the characteristics of a valve by adjusting an air flow rate output from an output port of a pilot valve, and an air flow rate adjusting method used therefor Relates to the device.

  Conventionally, a positioner has been used for valve drive control, process automation, and drive control of other general industrial equipment. By attaching this positioner to a valve, the drive control of the valve is made possible.

  By the way, since the positioner generally controls the drive of the valve with air, it is necessary to adjust the air pressure according to the type of the valve. It is difficult to drive all valves with one type of positioner because there are countless diameters, but it is impossible to manufacture positioners for all valve types. . For this reason, conventionally, a fixed aperture having an appropriate value has been incorporated in the manufacture of the positioner for specifications that are known in advance.

  However, it is impossible to incorporate such a fixed restrictor because spare parts do not know the valve specifications in advance, and it is troublesome for the purchaser to order each size. Since this is not possible, if the positioner does not fit when it is mounted on the valve, it must be replaced, which increases the cost.

  Also, a method of processing by adding a commercially available speed controller to the positioner can be considered, but this may cause a problem that the cost becomes high. In addition, there are many cases where a satisfactory conforming value cannot be obtained just by reducing the air flow rate of the output circuit, and it is pointed out that even if the overall speed can be adjusted, the sensitivity with a small signal does not improve. .

Furthermore, in the past, there has also been a method of branching a part of the pilot valve output circuit, providing a small hole in the branch circuit, and arranging an appropriate one of a plurality of types of bleeders in the small hole. Although this method has been proposed, it is necessary to prepare a plurality of types of bleeders, which increases the cost and also makes it difficult to install the bleeder.
JP 2001-99332 A

  Accordingly, an object of the present invention is to provide a positioner that can easily change the speed of the valve and also perform sensitivity adjustment and an air flow rate adjusting device used therefor.

  The positioner of the present invention includes a pilot valve for supplying air to a drive unit to which a valve is connected via a conducting pipe, an operation control unit for controlling the operation of the pilot valve, and driving of the drive unit And a drive control means for adjusting the adjustment valve, wherein the adjustment valve is movably disposed in the vicinity of the output port of the pilot valve in the conduction pipe, and the inner diameter of the conduction pipe is blocked by the adjustment valve. In addition, the central portion of the adjustment valve is perforated to form a small hole so that a part of the air supplied through the output port can be discharged to the outside, and thereby the air passing through the conduction pipe The feature is that the flow rate can be adjusted.

  The air flow rate control device of the present invention is a positioner air flow rate control device disposed in the vicinity of an output port of a pilot valve in a conduction pipe connected to a pilot valve in the positioner, wherein the conduction pipe is connected. Air passage, an insertion path formed so as to intersect the air flow path, an adjustment valve movably inserted into the insertion path, and an adjustment valve formed on the adjustment valve from the output port. And a small discharge hole for discharging a part of the output pressure to the outside.

  According to the present invention, it is possible to block the air supplied from the output port, thereby adjusting the air flow rate, and further releasing a part of the air supplied through the output port to the outside. Therefore, it is possible to easily change the speed of the valve, and it is also possible to easily perform minute sensitivity adjustment when changing the speed.

  In the positioner of the present invention, a pilot valve connected to a conducting pipe for supplying air to a drive unit to which the valve is connected, an operation control unit for controlling the operation of the pilot valve, and driving of the drive unit And a drive control means for adjusting the adjustment valve, and an adjustment valve is movably disposed near the output port of the pilot valve in the conducting pipe. Further, the adjustment valve is perforated at the center thereof. Thus, a small hole is formed so that a part of the air supplied through the output port can be discharged to the outside.

  The air flow rate adjusting device of the present invention includes an air path to which a conducting pipe for supplying air to a drive unit to which a valve is connected is connected, an insertion path formed in a direction orthogonal to the air path, An adjustment valve that is movably inserted into the insertion path and a discharge small hole that is formed in the adjustment valve and discharges a part of the output pressure supplied from the output port to the outside are provided.

  Here, the small valve may be movably inserted into the discharge small hole in the adjustment valve, thereby finely adjusting the amount of air discharged from the small hole, and finer sensitivity adjustment. Can be done.

  An embodiment of the positioner of the present invention will be described with reference to the drawings. FIGS. 1 and 2 are views for explaining the structure of the positioner of the present embodiment. FIG. 1 shows a single-acting positioner. 2 shows a double-acting type positioner. Further, FIGS. 1 and 2 show ones using an electric input unit, but the operation principle is almost the same, so FIG. It explains using.

  That is, the position indicated by a two-dot chain line in FIG. 1 is the positioner 1, and when the positioner 1 is used, the positioner 1 is communicated with the drive unit 51 by the conducting pipe 71, and thereby the valve connected to the drive unit 51. The pilot valve 21 for driving the drive unit 51 and the operation control unit for controlling the operation of the pilot valve 21. 2 and drive control means 41 for controlling the drive of the drive unit 51.

  Here, first, the drive unit 51 will be described. The drive unit 51 includes a movable wall 53, and a drive unit pressure chamber 52 is formed in an arrangement partitioned by the movable wall 53. The pressure pipe 52 communicates with the conducting pipe 71.

  In addition, a stem 54 is connected to the counter driving portion pressure chamber side of the movable wall 53, and a valve is connected to a tip portion of the stem 54.

  With this configuration, when air is supplied into the drive unit pressure chamber 52 through the conducting pipe 71, the movable wall 53 expands toward the stem 54, thereby causing the stem 54 to move to the connected valve side. It is possible to move and drive the valve.

  In the figure, reference numeral 55 denotes a spring for controlling the expansion of the movable wall 52, and a feedback bag is added to the expansion of the movable wall 53 by the spring 55.

  Next, the pilot valve 21 constituting the positioner 1 of the present embodiment will be described. The pilot valve 21 includes a primary pressure chamber 22a having an air supply port 2201 and a secondary pressure chamber communicated with the primary pressure chamber 22a. An air supply pressure chamber 22 constituted by a side pressure chamber 22b is provided, and the secondary side pressure chamber 22b is provided with an output port 2202 communicating with the drive unit pressure chamber 52 through a conduction pipe 71. .

  An air supply valve seat 23 is formed between the primary side pressure chamber 22a and the secondary side pressure chamber 22b, and a space formed by the air supply valve seat 23 serves as an air supply passage.

  Further, one end portion of an exhaust valve seat 29 is movably inserted into the secondary side pressure chamber 22b, and the exhaust valve seat 29 is opened in the secondary side pressure chamber 22b and at any location. Thus, an exhaust passage 2901 is formed in which an exhaust port 2902 communicating with the outside is formed.

  Further, a valve body 24 having a supply valve 2401 and an exhaust valve 2402 concentrically integrated in the supply pressure chamber 22 is provided by the supply valve 2401, the supply passage, and the exhaust valve 2402. It is inserted by a spring so that the opening of the exhaust passage 2901 can be closed.

  Next, a nozzle back pressure chamber 26 is formed in the pilot valve 2, and one end of the nozzle back pressure chamber 26 communicates with the primary pressure chamber 22a.

  A pressure chamber 27 is formed in the pilot valve 21, and an air supply pipe 72 is connected to the pressure chamber 27. The nozzle back pressure chamber 26 and the pressure chamber 27 are partitioned by a partition wall such as a diaphragm 28, and a partition wall such as a diaphragm is also provided on the side of the pressure chamber 27 facing the nozzle back pressure chamber 26. The valve seat 29 is movably provided in a form supported by the diaphragm 28.

  In such a configuration, when the exhaust valve seat 29 moves toward the primary pressure chamber 22a in a state where air is supplied into the supply pressure chamber 22 through the air supply pipe 72, the valve body 24 is moved. Is moved upward in the same direction as the movement direction of the exhaust valve seat 29 so as to be pushed up by the exhaust valve seat 29, whereby the air supply valve seat 23 is opened. Then, the air supplied into the primary side pressure chamber 22a is supplied to the secondary side pressure chamber 22b through the air supply passage, and also supplied to the drive unit pressure chamber 52 via the output port 2202 and the conduction pipe 71. As a result, the partition wall 53 expands toward the stem 54 and the stem 54 moves toward the valve, whereby the valve connected to the stem 54 can be driven.

  Next, in FIG. 1, 31 is an air flow rate adjusting device, that is, in this embodiment, air supplied to the drive unit 51 via the conducting pipe 71 in the vicinity of the output port 2202 in the conducting pipe 71. An air flow rate adjusting device for adjusting the flow rate is provided.

  Here, FIG. 3 is a cross-sectional view showing the structure of the air flow control device 31, and FIG. 4 is a bottom view showing the air flow control device 31 of this embodiment from the direction A in FIG.

  The air flow rate adjusting device 31 in this embodiment includes a substantially cylindrical main body 32, and the main body 32 is connected to the conduction pipe 71 and passes air supplied from an output port 2202. A possible air flow path 33 is formed, whereby the air flow rate adjusting device 31 is disposed in the vicinity of the output port 2202 in the conduction pipe 71, and is driven to the drive unit 51 side via the air flow path 33. Air can be supplied.

  Next, an insertion path 34 is formed in the main body portion 32 so as to intersect in a direction substantially orthogonal to the air flow path 33, and the lower end portion of the insertion path 34 is opened to the outside of the main body portion 32. And the upper end is closed.

  An adjustment valve 35 having a small hole 37 having openings 3701 and 3702 at both ends is moved in the insertion path 34 so that the insertion path 34 can communicate with the outside through the small hole 37. By being screwed together freely, the air taken in from the small hole 3701 on the insertion side can be discharged to the outside through the small hole 3702 on the external side.

  In such a configuration, when the adjustment valve 35 is advanced toward the air flow path 33 to close the air flow path 33, the air flow rate passing through the air flow path 33 can be reduced. Thus, it is possible to change the speed of the valve connected to the drive unit 51.

  At that time, in the air flow rate adjusting device 31 according to the present embodiment, a small hole 37 is formed in the adjustment valve 35, and the adjustment valve is arranged so that the insertion path 34 can communicate with the outside through the small hole 37. Since 35 is screwed into the insertion path 34, a part of the air supplied to the drive unit 51 side via the air flow path 33 can be discharged to the outside via the small hole 37. Therefore, when the adjustment valve 35 is moved forward to change the speed of the valve connected to the drive unit 51, it is possible to effectively prevent the valve from moving too rapidly.

  Here, FIG. 5 is a cross-sectional view showing another form of the air flow rate adjusting device 31 in the present invention. In the air flow rate adjusting device 31 shown in FIG. A small valve 38 having a tapered diameter and an air flow path having an upper and lower opening therein is movably inserted so that air can be discharged to the outside via the small valve 38. By adjusting the insertion ratio of the small valve 38 to the small hole 37, the amount of air discharged to the outside through the small hole 37 can be finely adjusted. Therefore, in the air flow rate adjusting device 31 shown in FIG. 5, it is possible to perform finer sensitivity adjustment when changing the valve speed.

  3 and 5, reference numeral 36 denotes a screw for locking the adjusting valve 35 in the insertion path 34, that is, the screw 36 prevents the adjusting valve 35 from falling off the main body 32. In the figure, reference numeral 39 denotes a sealing O-ring interposed between the inner wall of the insertion path 34 and the adjustment valve outer periphery.

  In the positioner of the present invention, the adjustment valve 35 can be movably disposed in the vicinity of the output port 2202 of the pilot valve 21 in the conduction pipe 71, and the inner diameter of the conduction pipe 71 can be blocked by the adjustment valve 35. In addition, the central portion of the adjustment valve 35 may be perforated to form a small hole 37 so that a part of the air supplied through the output port 2202 can be discharged to the outside, and is not necessarily described above. There is no need to use an air flow control device.

  Next, in FIG. 1, 2 is an operation control unit, and this operation control unit 2 is used to operate the exhaust valve seat 29 in the pilot valve 21. That is, the operation control unit 2 is provided with a coil 4, and an outer periphery of the coil 4 is provided with a yoke 5 and a magnet 14 for reinforcing the magnetic force of the yoke 5. Further, an armature 6 that moves by applying a signal current to the coil 4 penetrates the coil 4, and a flapper 8 is attached to the armature 6, and a magnetic force is generated by applying a signal current to the coil 4. The generated magnetic force is amplified by the yoke 5 and the magnet 14, and the armature 6 is movable by the amplified magnetic force.

  In addition, the operation control unit 2 includes a nozzle 9 communicated with the nozzle back pressure chamber 26 by an air pipe 10, and the flapper 8 opens and closes the nozzle 9 by increasing or decreasing an input signal current to the coil 4. It is arranged to be movable in the direction of closing the block or in the direction of releasing the block. That is, the armature 6 is supported by the fulcrum spring 7 in such a manner that when the signal current is applied to the coil 4, the flapper 8 moves in a direction capable of releasing the blockage with the tip of the nozzle 9. As a result, the flapper 8 moves in the direction of closing the nozzle 9 or the direction of releasing the blocking, by increasing or decreasing the signal current.

  Next, reference numeral 41 in FIG. 1 denotes drive control means used for controlling the drive of the drive unit 51. That is, in this embodiment, 41 is connected to an arbitrary portion of the stem 54 in the drive unit 51. Feedback levers 42 and 43 are provided. The feedback levers 42 and 43 are connected to a cam 44 so that the cam 44 rotates when the stem 42 moves.

  On the other hand, the tip of the range adjusting arm 45 is in contact with the cam 44, and when the cam 44 rotates, the range adjusting arm 45 rotates counterclockwise around the fulcrum.

  A bearing shaft 46 is connected to the range adjusting arm 45, and a zero adjusting arm 47 is brought into contact with the bearing shaft 46, and the range adjusting arm 45 rotates counterclockwise as the cam 44 rotates. Then, the zero adjustment arm 47 rotates clockwise around the fulcrum while sliding on the bearing shaft 46.

  Further, one end of a feedback spring 48 is connected to the tip of the zero adjustment arm 47 (on the side opposite to the fulcrum), and when the zero adjustment arm 47 rotates clockwise as the cam 44 rotates, the feedback spring 48 is rotated. 48 is pulled up.

  Furthermore, the other end of the feedback spring 48 is connected to the flapper arm 11 connected to the armature 6, whereby the feedback spring 48 is pulled upward so that the flapper 8 closes the tip of the nozzle 9. It is returned to the direction to do.

  Next, the operation of the positioner of this embodiment configured as described above will be described. In a state where air is supplied into the supply pressure chamber 22a via the air supply pipe 72 (state shown in FIG. 1), the coil When a signal current is applied to the armature 4, the armature 6 moves around the fulcrum spring 7 in the direction in which the flapper 8 releases the blockage of the tip of the nozzle 9, that is, in the direction of arrow A in the figure. Then, the flapper 8 is pulled away from the tip of the nozzle 9 by the movement of the armature 6, thereby releasing air from the nozzle 9 and reducing the pressure in the nozzle back pressure chamber 26, and the nozzle back pressure chamber 26 and the pressure chamber 27. The air pressure balance is lost.

  Then, the diaphragm 28 partitioning the nozzle back pressure chamber 26 and the pressure chamber 27 moves to the nozzle back pressure chamber 26 side, and the exhaust valve seat 29 supported by the diaphragm 28 is connected to the supply pressure chamber 22a side. Move to.

  As a result, the exhaust valve seat 29 pushes up the valve body 24, and accordingly, in the pressure chamber 22, the supply valve seat 23 is opened, the exhaust passage 2901 of the exhaust valve seat 29 is closed, and the output port 2202. In addition, air is supplied into the drive unit pressure chamber 52 through the conduction pipe 71, whereby the partition wall 53 expands toward the stem 54, thereby moving the stem 54.

  Next, as the stem 54 moves, the cam 44 rotates in the clockwise direction (arrow C direction) via the feedback levers 42 and 43, and the rotation of the cam 44 causes the range adjustment arm 45 to center on the fulcrum. Rotate in the counterclockwise direction (arrow D direction).

  Then, when the range adjustment arm 45 rotates counterclockwise, the zero adjustment arm 47 supported by the bearing shaft 46 rotates clockwise about the fulcrum (in the direction of arrow E), thereby the feedback spring. 48 is pulled up (in the direction of arrow F), the flapper arm 11 is pulled up, and when the tension of the feedback spring 48 and the suction force of the coil 4 are balanced, the flapper 8 closes the tip of the nozzle 9. Approaching.

  Then, the air discharged from the nozzle 9 decreases and the pressure in the nozzle back pressure chamber 26 increases, and the balance of the air pressure in the nozzle back pressure chamber 26 and the pressure chamber 27 approaches the initial state. The diaphragm 28 partitioning the chamber 26 and the pressure chamber 27 moves toward the pressure chamber 27, and the exhaust valve seat 29 supported by the diaphragm 28 approaches the initial position. As a result, the supply valve 2401 moves in the direction of closing the supply valve seat 23 in the supply pressure chamber 22a.

  As a result, the amount of air supplied to the drive unit pressure chamber 52 decreases and the movement of the stem 54 stops. That is, the stem 54 moves until the tension of the feedback spring 48 and the attractive force of the coil 4 are balanced, thereby obtaining a change in the stem 54 proportional to the input signal current.

  At this time, in the positioner according to the present embodiment, the air flow rate adjusting device 31 is disposed in the vicinity of the output port 2202 of the pilot valve 21 in the conducting pipe 71, and the air flow rate adjusting device 31 causes the drive unit pressure from the conducting pipe 71. Since the flow rate of air supplied to the chamber 52 can be adjusted, the speed can be easily changed according to the type of the valve, and the sensitivity of the valve can be finely adjusted. Thus, it is possible to perform air adjustment corresponding to many types of valves.

  In addition to the single-acting positioner, there are double-acting positioners. In addition to the electric type that uses the input signal as an electrical signal, there are also air-and-air positioners that use the input signal as air pressure. In the above description, the electric single-acting positioner has been described. However, in the present invention, an air flow rate adjusting device is provided in the vicinity of the output port of the pilot valve in the conducting pipe for supplying air to the drive unit. Thus, since the flow rate of air supplied to the drive unit can be adjusted, the present invention can be applied to all positioners that drive the drive unit with air.

It is a figure for demonstrating the Example of the positioner of this invention. It is a figure for demonstrating the Example of the positioner of this invention. It is sectional drawing for demonstrating the structure of the air flow control apparatus used for the Example of the positioner of this invention. FIG. 4 is a T bottom view showing an air flow rate adjusting device used in an embodiment of the positioner of the present invention from the direction A in FIG. 3. It is sectional drawing for demonstrating the structure of the other form of the air flow control apparatus used for the Example of the positioner of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Positioner 2 Operation control part 3 Torque motor 4 Coil 5 Yoke 6 Armature 7 Support spring 8 Flapper 9 Nozzle 10 Air pipe 11 Flapper arm 21 Pilot valve 22 Supply pressure chamber 22a Primary side pressure chamber 22b Secondary side pressure chamber 2201 Supply air Port 2202 Output port 23 Supply valve seat 24 Valve body 2401 Supply valve 2402 Exhaust valve 26 Nozzle back pressure chamber 27 Pressure chamber 28 Diaphragm 29 Exhaust valve seat 2901 Exhaust passage 2902 Exhaust port 31 Air flow control device 32 Main body 33 Air passage 34 Insertion path 35 Adjustment valve 36 Screw 37 Small hole 3701, 3702 Small hole opening 38 Small valve 39 O-ring 41 Drive control unit 42, 43 Feedback lever 44 Cam 45 Range adjustment arm 46 Bearing shaft 47 Zero adjustment arm 48 Feedback spring 51 drive 52 driver pressure chamber 53 partition wall 54 stem 55 spring

Claims (3)

A pilot valve (21) for supplying air to the drive unit (51) to which the valve is connected via the conducting pipe (71), and an operation control unit for controlling the operation of the pilot valve (21) ( 2) and a positioner (1) comprising drive control means (41) for controlling the drive of the drive unit,
An adjustment valve is movably disposed near the output port of the pilot valve (21) in the conduction pipe so that the inner diameter of the conduction pipe (71) can be blocked by the adjustment valve. The central part of the valve is perforated to form a small hole so that a part of the air supplied through the output port can be discharged to the outside, thereby making it possible to adjust the air flow rate through the conducting pipe (71). A positioner characterized by that. In the positioner, an air flow rate adjusting device for the positioner disposed in the vicinity of the output port of the pilot valve (21) in the conducting pipe (71) connected to the pilot valve (21),
An air path (33) to which the conducting pipe (71) is connected, an insertion path (34) formed so as to intersect the air path (33), and inserted into the insertion path (34) so as to be movable. A regulating valve (35) and a small discharge hole (37) formed in the regulating valve (35) for discharging a part of the output pressure from the output port to the outside. An air flow rate adjusting device device for a positioner characterized by The apparatus for adjusting an air flow rate of a positioner according to claim 2, wherein a small valve (38) is movably inserted in a small discharge hole (37) in the valve (35).