JPH09203401A - Range regulating device in positioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify regulation of a range by arranging a rapidly fastening means for locking a movable piece on the desired position of the slot of an arm coaxially with a center shaft, and mounting a bearing for supporting the lower circumferential part of a zero regulating arm. SOLUTION: A screw driver is engaged with a screw driver engaging groove 12 of the rapidly fastening means 14 arranged on one end of a center shaft 13, it is turned in a prescribed direction, and then the engaging degree of an arm 1 and a movable piece 5 is released. As a result, the movable piece 5 becomes in a free condition, and the movable piece 5 is moved along a slot 2 while prescriptively engaging a pinion gear 4 with a rack gear 3 arranged in parallel with the slot 2 on the arm 1. After prescribed range regulation is completed, the movable piece 5 is locked on the fixed position of the arm 1 by the rapidly fastening means 14. A bearing 9 for supporting the lower circumferential part of the zero regulating arm is mounted on the center shaft 13, functions of a bearing shaft 8, a rock screw, and a regulating screw are applied on one center shaft 13, releasing and fastening of the bearing shaft 8 are carried out by one hand, the movable piece 5 is moved by one hand, and thereby, it is possible to regulate a range in a single operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a range adjusting device in a positioner (position control device) used for valve drive control and other drive control of general industrial equipment. That is, although the positioner is one of the automatic control devices, since it is used in combination with the valve, the range adjustment of the valve stroke is indispensable depending on the size of the valve,
For this purpose, a range adjuster must be provided in the positioner. The present invention relates to a range adjusting device interposed between a feedback lever of a positioner and a feedback spring for this purpose.

The operation of the positioner will be described with reference to the block diagram of FIG. 6 in connection with the point that the range of the positioner must be adjusted.

When an input signal current is applied to a torque motor 21 of a positioner, an armature 22 moves in the direction of arrow A about a fulcrum spring 23. This armature 22
, The flapper 25 is separated from the nozzle 24, the pressure in the nozzle back pressure chamber 27 decreases, and the pressure chamber 26
And the relay spool 29 pushes the port 30 and the supply pressure passes through the output port 28 and is introduced into the drive unit pressure chamber 35 to move the stem 36 in the B direction, and the movement of the stem 36 is fed back. Lever 37,
The cam 39 is rotated via arrow 38 as shown by arrow C, the displacement of the cam 39 is transmitted to the range adjustment arm 31 in the direction of arrow D, and the zero adjustment arm 34 is rotated via arrow 32 to the arrow E. .

Since the feedback spring 40 is connected between the tip of the zero adjustment arm 34 and the flapper arm 41, the feedback spring 40 moves until the tension of the feedback spring 40 and the suction force of the torque motor 21 are balanced.
In this way, a change in stem 36 proportional to the input signal current is obtained.

There are various types of displacement of the stem 36 depending on the size of the driving section, and the bearing shaft 32 of the above-mentioned range adjusting arm 31 must be adjusted by moving the bearing shaft 32 to the left and right in order to adjust it to an appropriate value.

The same applies to a pneumatic positioner as shown in FIG. The operation is the same, except that the input signal has changed to air pressure.

[0007]

2. Description of the Related Art FIGS. 8, 9 and 10 are shown as an example of a conventional range adjusting device. More specifically, the range adjusting gear 56 is configured to mesh with the rack gear 57 and to roll on the center line of the long slot 52 of the arm 51 in conjunction with the slider 55. 54 and the bearing shaft 53 are connected with the arm 51 interposed therebetween.

To perform range adjustment, first loosen the lock screw 54 with a screwdriver, and
Is rotated clockwise or counterclockwise to roll on the center line of the slot 52. When the lock screw 54 is loosened, the slider 55 is in a free state, so that the bearing shaft 53 is inclined in the gap between the long slots 52, and a zero shift occurs.

Although the lock screw 54 and the adjusting gear 56 are arranged side by side, since each of them has a structure using a separate driver, it is impossible to perform one-touch adjustment at the same time. In addition, there was a problem that adjustment was difficult.

In the examples shown in FIGS. 11, 12 and 13 (other examples of the prior art), a movable piece 63 is mounted between two arms 61 and 62. The range adjustment is performed by loosening the bearing shaft 64 and turning the adjustment screw 65. At this time, the bearing shaft 64 is vertically moved as indicated by an arrow K, and a large zero shift occurs. Further, since the adjusting screw 65 and the bearing shaft 64 are displaced by 90 °, there is a problem that the adjustment is not easy.

The present invention is intended to solve the problems represented by these problems.

[0012]

1, 2, and 3, a movable piece having a rack gear 3 arranged in parallel with a slot 2 of an arm 1 and having a pinion gear 4 meshing with the rack gear 3 is provided. There is shown a range adjusting device in which the central shaft 13 is loosely fitted in the elongated slot 2 and is arranged so as to roll along the elongated slot 2. A tightening means 14 for locking the movable piece 5 at a required position of the long slot 2 of the arm 1 is provided coaxially with the center shaft 13, and the center shaft 13 is provided with a bearing shaft 8.
In this, a bearing 9 for supporting the lower side of the zero adjustment arm 34 is mounted, as shown in FIG.

As shown in FIGS. 4 and 5, it is preferable to dispose a rod-shaped lever 6 at one position on the circumference of the movable piece 5.

[0014]

When the range is to be adjusted, the tightening means 14 is first loosened. In the illustrated example, since the thread portion 7 of the center shaft 13 is screwed to the inner thread 7 ′ of the movable piece 5, the driver is engaged with the driver engagement groove 12 at one end of the center shaft 13. By rotating the center shaft 13 in a predetermined direction, the degree of engagement between the arm 1 and the movable piece 5 is loosened. As a result, the movable piece 5 is in a free state, and the movable piece 5 moves along the long slot 2 while the pinion gear 4 is engaged with the rack gear 3 provided on the arm 1 in parallel with the long slot 2. It is possible.

Next, a predetermined range adjustment is performed, and after the adjustment is completed, the movable piece 5 is locked (locked) at the fixed position of the arm 1 by the tightening means 14.

In the range adjusting device of the present invention, as described above, the three functions of the bearing shaft, the lock screw, and the adjusting screw are provided on one central shaft 13, so that the range adjustment is performed. In this method, the bearing shaft 8 is loosened and tightened with one hand, and the movable piece 5 or the rod-shaped lever 6 is moved with one hand to perform one-touch range adjustment. Therefore, even a beginner can easily adjust the range. In this device, the zero adjustment arm 3 is
The fact that the bearing 9 supporting the lower side of 4 is mounted is convenient for the above-described range adjustment operation.

As shown in FIGS. 4 and 5, when a bar-shaped lever 6 is provided on the movable piece 5, the movable range of the tip of the lever 6 is large, which is convenient for fine adjustment.

A pinion gear 4 is provided on the movable piece 5,
Because it is designed to mesh with the rack gear 3 of the arm 1,
There is no slip when rolling the meshing portion, and swinging of the center shaft 13 which also serves as a bearing shaft is prevented, so that there is no dead zone at the time of repetitive operation at the time of adjustment, and adjustment can be easily performed.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In contrast to the one shown in FIGS. 1, 2 and 3 (first embodiment), the one shown in FIGS. Is projected.

[0020]

As described above, according to the present invention, it is possible to achieve a truly excellent range adjusting device.

[Brief description of drawings]

FIG. 1 is a front view of a first embodiment of the device of the present invention.

FIG. 2 is a sectional side view of the same as above.

FIG. 3 Same as above

FIG. 4 is a front view of a second embodiment of the device of the present invention.

FIG. 5 is a sectional side view of the same as above.

FIG. 6 is a configuration diagram showing the existence of a range adjusting device in a positioner.

FIG. 7 is a structural part showing the existence of a range adjusting device in a pneumatic positioner.

FIG. 8 is a front view of an example of a conventional range adjusting device.

FIG. 9 is a sectional view taken along the line GG of the above.

10 is a cross-sectional side view taken along the line HH of FIG.

FIG. 11 is a plan view of another example of the conventional range adjusting device.

FIG. 12 is a front view of the same.

FIG. 13 is a side view of the JJ cross section of the above.

[Explanation of symbols]

 1 Arm 2 Long Groove 2'Circular Guide 3 Rack Gear 4 Pinion Gear 5 Movable Top 6,33 Rod Lever 7 Threaded Part 7'Internal Thread 8,32 Bearing Shaft 9 Bearing 12 Driver Engagement Groove 13 Center Shaft 14 Tightening Means 21 torque motor 22 armature 23,43 fulcrum leaf spring 24 nozzle 25 flapper 26 pressure chamber 27 nozzle back pressure chamber 28 output port 29 relay spool 30 port 31 range adjustment lever 34 zero adjustment arm 35 drive unit pressure chamber 36 stem 37, 38 feedback Lever 39 Cam 40 Feedback spring 41,44 Flapper arm 42 Input pressure chamber 54 Lock screw 55 Slider 56 Range adjustment gear 65 Adjustment screw

Claims (2)

[Claims] 1. A pinion gear 4 in which a rack gear 3 is arranged in parallel with an elongated slot 2 of an arm 1 and meshes with the rack gear 3.
A movable top 5 having a central axis 13 of the elongated slot 2
In the range adjusting device arranged so as to roll along with, the tightening means 14 for locking the movable piece 5 at a required position of the slot 2 of the arm 1 is provided coaxially with the central shaft 13. The zero adjustment arm 3 is attached to the center axis 13.
4. A range adjusting device, characterized in that a bearing 9 for supporting the lower side of 4 is mounted. 2. The range adjusting device according to claim 1, wherein a rod-shaped lever 6 is provided at one position on the circumference of the movable piece 5.