JP4344627B2 - Positioner concentric lever - Google Patents

Description

  The present invention relates to a concentric lever mounted on a positioner, and more particularly, to a concentric lever of a positioner that can prevent loosening due to vibration of the positioner and dropout caused by the loosening.

  In general, when driving a valve, the valve is driven by moving the stem using a drive unit having a stem to which the valve is connected. Conventionally, in positioners used for valve drive control, process automation, and drive control of other general industrial equipment, automatic control of the valve is performed by controlling the movement of the stem. Some positioners for controlling these valves have a concentric lever interposed between the stem and the positioner so that the movement of the valve can be detected visually.

  That is, in FIG. 5, P is a positioner for controlling the rotary valve. As shown in the figure, generally, in the positioner for controlling the rotary valve, the rotation of the valve is detected visually. A scale 47 and a pointer 46 are provided for enabling. Then, it is possible to move the pointer 46 on the scale 47 in accordance with the rotation of the valve by using a concentric lever, and thereby the rotation of the valve can be visually detected via the pointer 46.

  Here, FIGS. 7 and 8 are views for explaining a conventional concentric lever, in which 77 is a conventional concentric lever. In the figure, 52 is a camshaft in the positioner, and in FIG. 7, 64 is a stem (drive shaft) in the drive unit 61 for driving the valve.

  The conventional concentric lever 77 includes an arm B71 connected to the camshaft 52 and an arm A73 connected to the stem 64. By connecting the arm A73 and the arm B71, the rotation of the valve can be performed. In addition, the pointer 46 can be moved.

  That is, the arm B71 has a through hole 7101 through which the camshaft 52 penetrates, and the transmission pin 72 is continuously provided on the lower surface. After passing through the arm B71, a screw 76 is screwed into a screw hole formed in the axial direction of the camshaft 52, thereby fixing the arm B71 to the camshaft 52 while fixing the pointer 46.

  Next, the arm A73 has an engagement groove 7301 with which the transmission pin 72 is engaged by making the tip bifurcated, and a transmission shaft 74 is continuously provided on the lower surface. While engaging the transmission pin 72, the transmission shaft 74 is screwed onto the stem 64 and the connecting portion between the transmission shaft 74 and the stem 52 is tightened by the nut 75, thereby concentrically between the stem 64 and the camshaft 52. Install the lever 77.

  In this state, when the concentric lever 77 rotates in accordance with the rotation of the stem 64, the pointer 46 moves on the scale 47, so that the rotation of the valve can be visually detected. In FIG. 8, reference numeral 79 denotes a mounting bracket, and reference numeral 78 denotes a mounting screw for mounting the mounting bracket 79 to the positioner and the drive unit.

  As is well known, since the positioner is provided with a feedback mechanism, when performing automatic valve control, the stem obtains a change proportional to the input signal. In some cases, a strong vibration force is generated, and the positioner continues to vibrate. Therefore, as shown in FIG. 7, in the method in which the concentric lever is attached to the camshaft by a screw and the connection between the stem 64 and the concentric lever 77 is screwed, the screw is loosened by the vibration, thereby increasing the scale. There may be a problem that the accuracy of the pointer moving is reduced. In addition, it can be predicted that the concentric lever will fall off the camshaft due to the loosening of the screws, and in this case, the valve may not be automatically controlled.

  At this time, a method of bonding the coupling portion and the camshaft with an adhesive or the like is also conceivable. However, in this case, there is a problem that the removal becomes difficult.

  Accordingly, an object of the present invention is to provide a concentric lever for a positioner that can effectively prevent loosening of the concentric lever and dropout due to the concentric lever in a positioner that controls a rotary valve.

The concentric lever of the positioner according to the present invention is a concentric lever of the positioner which is coupled to the camshaft of the positioner and is engaged with a stem to which the valve is connected, thereby enabling the rotation of the valve to be visually detected. The camshaft is connected to a connecting portion having a through-hole, legs connected to both ends of the connecting portion in the same direction, and a stem communicating between the legs. It is characterized with the transmission shaft engageable with the engaging groove, further comprising a, and anti-vibration pad which is挿装between transmission and the coupling unit -axis.

  In the concentric lever of the positioner according to the present invention, a vibration-proof pad is inserted between the coupling portion and the transmission shaft, thereby pressing a screw for connecting the coupling portion and the camshaft in the insertion direction. . Therefore, even when the stem vibrates violently, the screw does not loosen, and it is possible to effectively prevent the concentric lever from loosening or dropping off.

  The concentric lever of the positioner according to the present invention includes a coupling portion in which a through-hole to which the camshaft of the positioner is coupled is formed, and a through-hole is formed in the vicinity of the lower end portion at both ends of the coupling portion. Legs are connected.

  In addition, a transmission shaft that can be connected to the stem is communicated between the pair of leg portions so that both end portions of the leg portions are locked to the leg portions while penetrating through through holes formed in the leg portions.

Then, said between coupling portion and the transmission shaft, vibration-proof pads are挿装, this anti-vibration pad, screwed to the camshaft of the positioner that penetrate the through-hole formed in the coupling portion thread Can be pressed in the insertion direction.

  At this time, an engaging shaft that can be engaged with an engaging groove formed in the stem, a connecting portion that is connected to both ends of the engaging shaft in the same direction, and an upper end portion of the connecting portion. An auxiliary arm having a formed through-hole through which the transmission shaft passes is made to pass through the transmission shaft through a through-hole formed in the connection portion in such an arrangement that the connection portion side is a concentric lever side. It is preferable to adjust the dimensions of the connecting portion so that the engaging shaft can come into contact with the anti-vibration pad when the auxiliary arm is rotated 90 degrees or more while being attached to a pair of leg portions. When engaging a stem with a diameter larger than the dimension between the parts, engage the engaging shaft of the auxiliary arm with the stem, while when engaging with a stem with a diameter smaller than the dimension between the legs, Rotate the arm 90 degrees or more to make contact with the anti-vibration pad In the state, it is possible to engage the transmission shaft to the stem, it is possible to alternate on both the small stem of a large stem and the diameter of the diameter.

  An embodiment of the concentric lever (hereinafter simply referred to as “concentric lever”) of the positioner according to the present invention will be described. FIG. 1 is a perspective view showing the concentric lever of the present embodiment. In FIG.

  The concentric lever 40 includes a coupling portion to which the camshaft of the positioner is coupled, that is, 4003 is a coupling portion in the figure, and in the present embodiment, the coupling portion 4003 has a flat plate shape. A through hole 4002 through which the camshaft passes is formed in the substantially central portion. In use, like the above-described conventional concentric lever, the camshaft is passed through the through hole 4002 with the pointer 46 moving on the scale on the camshaft, and then the screw 44 is screwed into the camshaft. This attaches the concentric lever 40 to the positioner.

  Next, leg portions 4001 are connected to both end portions of the coupling portion 4003, respectively, so that the concentric lever 40 has a substantially U-shaped front shape. And between the said leg parts 4001, the transmission shaft 43 is latched so that both ends may penetrate the through-hole 4004 formed in the lower part of each leg part 4001, The both ends of this transmission shaft 43 are latched. A ring clip 42 is attached to the portion, thereby fixing the position of the transmission shaft 43.

  In the concentric lever 40 of this embodiment, a rubber vibration-proof pad 41 is inserted between the lower surface of the coupling portion 4003 and the transmission shaft 43. As a result, the anti-vibration pad 41 presses the screw 44 inserted into the through hole side from the back surface of the coupling portion 4003 toward the coupling portion 4003, and the screw 44 even when severe vibration due to the rotation of the stem is repeated. Can be prevented from loosening. The vibration-proof pad 41 has a dimension between the coupling portion 4003 and the transmission shaft 43 when the vibration-proof pad 41 is inserted so that it cannot be easily taken out, that is, the transmission shaft 43 slightly bends to the stem side. It is good to make it about the size.

  Further, it is preferable to form a recess in which the screw 44 is accommodated in the vibration isolating pad 41, so that the screw 44 can be pressed to the coupling portion 4403 side while being accommodated in the recess.

  In the figure, reference numeral 4301 denotes a center groove formed in the transmission shaft 43. This center groove 4301 is a groove for aligning the center when the vibration-proof pad 41 is inserted. Further, in the figure, reference numeral 4101 denotes a rib formed on the vibration-proof pad 41.

  Next, a method of using the concentric lever 40 of the present embodiment configured as described above will be described. When the concentric lever 40 of the present embodiment is attached, as shown in FIG. The through hole 4601 of the pointer 46 and the through hole 4402 of the coupling portion 4403 are penetrated by the through portion 5201 of the lower portion of the camshaft 52, and then the screw 44 is screwed into the camshaft 52 from the back surface of the coupling portion 4403. As a result, the concentric lever 40 is mounted on the camshaft 52. After that, the vibration isolating pad 41 is disposed on the lower surface of the coupling portion 4003 and the transmission shaft 43 is mounted between the leg portions 4001, and the transmission shaft 43 is inserted into the engagement groove 6401 of the stem 64 in the arrangement as shown in FIG. Engage.

  Then, as the valve, that is, the stem 64 is rotated, the concentric lever 40 is rotated and the pointer 46 is moved on the scale 47, so that the rotation of the valve can be visually detected, and the anti-vibration pad 41 is used for screwing. 44 is pressed toward the coupling portion 4403 side, so that even if the stem 64 rotates vigorously and vigorous vibration continues, the screw 44 does not loosen and the concentric lever 40 can be prevented from falling off the camshaft 52. .

  Some stems do not have an engaging groove. In that case, a cap or the like having an engaging groove is previously attached to the stem, and the transmission shaft 43 is engaged with this cap. It is good to let them.

  Next, the operation of the positioner having the concentric lever of this embodiment will be briefly described. In FIG. 4, 61 is a drive unit having a stem 64 to which a rotary valve is connected. The primary drive part pressure chamber 62a is formed between the pistons 63 by arranging a pair of pistons 63 opposite to each other, and a secondary drive part pressure chamber 62b is formed outside the piston 63. Further, a rotary stem 64 is disposed between the pair of pistons 63, and the pair of pistons 63 are engaged with the stems 64, respectively, so that the primary drive unit pressure chamber 62a or the secondary drive unit pressure. The stem 64 can be rotated by supplying air into the chamber 62b.

  In the figure, the portion indicated by a two-dot chain line is the positioner 1, and the positioner shown in the figure is an electropneumatic double-acting positioner. The positioner 1 includes a pilot valve 21 that drives the stem 64 by supplying air to the primary drive unit pressure chamber 62 a or the secondary drive unit pressure chamber 62 b provided in the drive unit 61, and the pilot valve 21. The input unit 2 for operation and the drive control unit 51 for adding feedback to the movement of the stem 64 are configured.

When a signal current is applied to the coil 4 of the input unit 2, the armature 8 is centered on the fulcrum leaf spring 9 by the magnetic force flowing through the side plate 7, the yoke 5 and the magnet 6, and the flapper 10 is at the tip of the nozzle 11. It moves in the direction of releasing the occlusion in the direction of arrow A in the figure. Then, the flapper 10 is pulled away from the tip of the nozzle 11 by the movement of the armature 8, thereby releasing air from the nozzle 11 and reducing the pressure in the nozzle back pressure chamber 28 provided in the pilot valve 21. The balance of air pressure between the back pressure chamber 28 and the supply air pressure chamber 29 is lost. Then, the diaphragm 30 partitioning the nozzle back pressure chamber 28 and the supply air pressure chamber 29 moves to the nozzle back pressure chamber 28 side, and the spool 31 supported by the diaphragm 30 is connected to one side of the supply pressure chamber. The spool 31 pushes up the valve body 27a along with the movement, and accordingly, one of the supply valve seats 26a is opened and one of the openings in the exhaust passage 3101 of the spool 31 is closed. In addition, the other side of the exhaust path 3101 is an opening.

  The supply air supplied to one of the supply pressure chambers 22a through the air supply pipe 33 passes through one of the supply valve seats 26a, the output pressure chamber 23a, the throttle mechanism 36, and one of the conduction pipes 34a. Supplied to the side driver pressure chamber 62a.

  Next, when air is supplied into the primary side drive section pressure chamber 62a, the pair of pistons 63 move away from each other, and the stem 64 rotates in the clockwise direction, and is connected to the stem 64. A rotating valve (not shown) also rotates in the same direction.

  Next, as the stem 64 rotates, the transmission shaft 43 engaged with the stem 64 also rotates, and thereby the concentric lever 40 rotates. Then, the camshaft 52 on which the concentric lever 40 is mounted, and the pointer 46 mounted between the camshaft 52 and the concentric lever 40 also rotate, and the pointer 46 moves on the scale 47, thereby The rotation of the valve can be detected visually.

  Next, the rotation of the cam shaft 52 causes the cam 54 to rotate in the counterclockwise direction (arrow C direction) in the figure, and the rotation of the cam 54 causes the range adjustment arm 55 to rotate counterclockwise about the fulcrum. Rotate in the direction (arrow D direction). Then, when the range adjustment arm 55 rotates counterclockwise, the zero adjustment arm 57 rotates clockwise around the fulcrum (in the direction of arrow E), whereby the feedback spring 59 is pulled up. (In the direction of arrow F), when the flapper arm 12 is pulled up and the tension of the feedback spring 59 and the suction force of the coil 4 are balanced, the flapper 10 approaches to close the tip of the nozzle 11.

  Then, the air discharged from the nozzle 11 decreases and the pressure in the nozzle back pressure chamber 28 increases, and the balance of the air pressure in the nozzle back pressure chamber 28 and the pressure chamber 29 approaches the initial state. The diaphragm 30 partitioning the chamber 28 and the pressure chamber 29 moves to the pressure chamber 29 side, and the spool 31 supported by the diaphragm 30 approaches the initial position. Accordingly, in one side 23a of the supply pressure chamber, the supply valve 2701a moves in a direction to close the supply valve seat 26a, and on the other side 23b of the output pressure chamber, the opening of the exhaust passage 3101 of the spool 31 is opened. Close it.

  As a result, the amount of air supplied to the primary side drive unit pressure chamber 62a decreases and the amount of air discharged from the secondary side drive unit pressure chamber 62b also decreases, and the movement of the stem 64 stops. I will do it. That is, the stem 64 moves until the tension of the feedback spring 59 and the attractive force of the coil 4 are balanced, thereby obtaining a change of the stem 64 proportional to the input signal current.

  Next, FIG. 2 is a cross-sectional view showing the structure of another embodiment of the concentric lever 40 of the present invention. In this embodiment, an auxiliary arm 45 is further attached to the transmission shaft 43, thereby a stem having a large diameter. Also, the concentric lever 40 can be engaged.

  The above-described concentric lever 40 employs a configuration in which the transmission shaft 43 is locked between the pair of leg portions 4001. In this case, the concentric lever 40 is engaged only with a stem having a diameter that can be inserted between the pair of leg portions. In the case of a stem having a diameter larger than the dimension between the pair of leg portions, the transmission shaft 43 cannot be engaged. Therefore, in this embodiment, a concentric lever that can be engaged even when the diameter of the stem is larger than the dimension between the pair of legs is used.

  2, 45 is an auxiliary arm, and FIG. 3 is a perspective view showing the auxiliary arm. In this embodiment, the auxiliary arm 45 is engaged with an engaging groove formed in the stem. A coupling shaft 4501 is provided, and at both ends of the engagement shaft 4501, a connecting portion 4502 is continuously provided in the same direction. A through hole 4503 through which the transmission shaft 43 passes is formed in the vicinity of the upper end of the connecting portion 4502. Then, the transmission shaft 43 is passed through the through hole 4503 so that the connecting portion 4502 side is on the concentric lever 40 side, so that the pair of leg portions 4501 are attached.

  As described above, in the concentric lever 40 of this embodiment, the auxiliary arm 45 having the engagement shaft 4501 that can be engaged with the engagement groove formed in the stem is attached to the transmission shaft 43. There is also an advantage that can be engaged.

  At this time, when the dimension of the connecting portion 4502 is adjusted and the auxiliary arm 45 is rotated 90 degrees or more to the concentric lever 40 side, the engaging shaft 4501 is brought into contact with the vibration isolating pad 41, more specifically, the rib 4101. It is good to be able to contact. Then, when engaging with a stem having a large diameter, the auxiliary arm 45 is engaged with the stem. On the other hand, when engaging with a stem having a small diameter, the auxiliary arm 45 is rotated to turn the auxiliary arm 45 into a concentric lever. The transmission shaft 45 can be engaged with the stem by retracting to the side, and a single concentric lever can be used for both a stem having a large diameter and a stem having a small diameter.

  The concentric lever of the positioner according to the present invention is provided with a vibration-proof pad, so that it is possible to effectively prevent the screw that is screwing the concentric lever with the camshaft from being loosened. Applicable to all.

It is a figure for demonstrating the Example of the concentric lever of this invention. It is a figure for demonstrating the other form of the concentric lever of this invention. It is a figure for demonstrating the other form of the concentric lever of this invention. It is a schematic block diagram for demonstrating the action | operation of the positioner using the concentric lever shown in FIG. It is a figure for demonstrating the usage method of the concentric lever of this invention. It is a figure for demonstrating the usage method of the concentric lever of this invention. It is a figure for demonstrating the conventional concentric lever. It is a figure for demonstrating the conventional concentric lever.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Positioner 2 Input part 4 Coil 5 Yoke 6 Magnet 7 Side board 8 Armature 9 Supporting leaf | plate spring 10 Flapper 11 Nozzle 12 Flapper arm 13 Nozzle back pressure introduction pipe 21 Pilot valve 22a, 22b Supply pressure chamber 23a, 23b Primary side output pressure chamber 24a, 24b Air supply port 25a, 25b Output port 26a, 26b Air supply valve seat 27a, 27b Valve body 2701a, 2701b Air supply valve 2702a, 2702b Exhaust valve 28 Nozzle back pressure chamber 29 Supply air pressure chamber 30 Diaphragm 31 Spool 32 Air Chamber 3201 Exhaust port 33 Air supply pipes 34a, 34b Conduction pipe 35 Fixed throttle 36 Restriction mechanism 40 Concentric lever 4001 Leg 4002 Through hole 4003 Coupling part 41 Anti-vibration pad 4101 Rib 42 Clip 43 Transmission shaft 4301 Center groove 45 Auxiliary arm 4 01 Engagement shaft 4502 Connection portion 4503 Through hole 46 Pointer 47 Scale 51 Drive control mechanism 52 Cam shaft 54 Cam 55 Range adjustment arm 56 Bearing shaft 57 Zero adjustment arm 58 Zero adjustment screw 59 Feedback spring 61 Drive portions 62a and 62b Drive portion pressure Chamber 63 Piston 64 Stem 6401 Engaging groove

Claims (3)

A positioner concentric lever coupled to a camshaft of the positioner and engaged with a stem to which the valve is coupled, whereby the rotation of the valve can be detected visually;
A coupling portion (4003) having a through hole (4002) to which a camshaft of the positioner is coupled, and leg portions (4001) continuously provided in the same direction at both ends of the coupling portion (4003). The transmission shaft (43) that can communicate with the engagement groove formed in the stem and communicated between the legs (4001), and is inserted between the coupling portion (4003) and the transmission shaft (43). positioner concentric lever, characterized by comprising a vibration isolation pad (41), the. An engagement shaft (4501) that can be engaged with an engagement groove formed in the stem, a coupling portion (4502) that is connected to both ends of the engagement shaft (4501) in the same direction, and An auxiliary arm (45) formed in the vicinity of the upper end portion of the connecting portion and having a through hole (4503) through which the transmission shaft (43) passes, the connecting portion (4502) side becomes the concentric lever (40) side. In such an arrangement, the pair of legs ( 4001 ) is mounted by passing the transmission shaft (43) through a through hole (4503) formed in the connecting portion (4502). The concentric lever of the positioner according to 1.   The dimension of the connecting portion (4502) is such that the engagement shaft (4501) can abut against the anti-vibration pad (41) when the auxiliary arm (45) is rotated 90 degrees or more. The concentric lever according to claim 2.

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