JP2899394B2 - Valve drive control device - Google Patents

Description

Description: Object of the Invention (Field of Industrial Application) The present invention relates to a valve drive control device, and in particular, to a valve drive control device provided with a limit torque mechanism for controlling a load acting on a valve stem. About.

(Prior Art) Normally, the opening and closing operation of a valve includes an air cylinder driving method using air and an electric driving method using a motor.
FIG. 6 shows a conventional example of a valve drive control device employing an electric drive system.

In the figure, reference numeral 1 denotes a valve stem. The valve stem 1 is screwed into an inner periphery of a stem nut 3 fixed to a drive sleeve 2. The drive torque of the motor 4 is transmitted to the valve stem 1 in the order of the worm shaft 5, the worm 6, the worm gear 7, and the drive sleeve 2, and moves up and down via the stem nut 3 in response to the rotation of the drive sleeve 2. Opens and closes the valve. If the valve hits the seat surface, the seat pressure is kept constant and the seal is maintained.
Further, a limit torque mechanism is provided to prevent an overload from being applied to the valve stem 1 when the valve has caught foreign matter.

 This limit torque mechanism will be described below.

The worm 6 has a structure in which the worm 6 is fitted to a spline of the worm shaft 5 and slides the bearing cartridge 8 in the axial direction. When the load on the valve stem 1 increases due to an increase in the seat surface pressure or the entry of foreign matter, the worm 6 and the bearing cartridge 8 push the disc spring 9 and move in the axial direction. When the disc spring 9 is contracted until this movement corresponds to a preset load, the limit switch 10 connected to the bearing cartridge 8 opens its contact and the motor 4 stops.
Thus, the limit torque mechanism operates. The sign
Reference numeral 11 denotes a casing.

(Problems to be Solved by the Invention) However, in the above-described valve drive control device, the load acting on the valve stem 1 includes the worm gear 7 and the worm 6
This force is detected as a force pressing the disc spring 9 through the interface, so that the load may not be accurately detected due to the influence of friction and the like of these parts. In such a case, the valve stem 1 may be damaged due to overload, or the seat surface pressure may be reduced due to insufficient load, resulting in leakage.

The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide a valve drive control device capable of accurately detecting a load acting on a valve stem and appropriately controlling valve drive.

[Configuration of the invention]

(Means for Solving the Problems) The invention according to claim 1 is provided such that a flexible member is interposed between a valve stem base element and a valve stem end element, and the valve stem is rotatably mounted on a casing. A valve stem elevating part for screwing the valve stem base element therein, a rotary drive source connected to the valve stem elevating part for rotating the valve stem elevating part, and a flexible member of the valve stem. An overload detector that detects an amount of deformation of the flexible member, and a control unit that receives a signal from the overload detector and that can stop operation of the rotary drive source, The flexible member is formed by vertically symmetrically combining two disc springs formed in a truncated cone shape, and the overload detector includes a light emitting unit installed on a slope of the one disc spring;
A light-receiving section provided on the slope of the other disc spring, and the light-emitting section emits light toward a space portion of the combined disc spring, and the light is received by the light-receiving section. It is a feature.

(Operation) The valve stem elevating unit rotates by the operation of the rotary drive source, whereby the valve stem is raised and lowered, and the valve element is opened and closed. If an overload acts on the valve stem during this operation, the flexible member of the valve stem is bent and deformed by the overload generated during opening and closing of the valve. The detector detects. That is, the light-emitting angle from the light-emitting unit is changed by the bending deformation of the flexible member, and the light-receiving position in the light-receiving unit is shifted to quantitatively measure the overload value. Next, the control unit stops the rotation drive source based on the detection signal of the overload detector.

As described above, according to the first aspect of the present invention, since the overload acting on the valve stem is directly detected by the bending deformation of the flexible member, the overload can be accurately detected. As a result,
Valve drive can be controlled appropriately.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing a first embodiment of a valve drive control device according to the present invention.

A valve body (not shown) is provided integrally with the distal end of the valve stem 21. The operation of the valve stem 21 is controlled by the valve drive control device 20. The valve drive control device 20 includes a drive sleeve 22 and a stem nut 23 as a valve stem elevating unit. The drive sleeve 22 is rotatably supported by an upper tapered roller bearing 24 and a lower tapered roller bearing 25 installed on its outer periphery. These upper and lower tapered roller bearings 24 and 25 are supported on a casing 28 by an upper load detector 26 and a lower load detector 27, respectively.

Further, the stem nut 23 is fixed integrally with the drive sleeve 22 by rotation and is positioned by the lock nut 29. A female screw 30 is engraved on the inner periphery of the stem nut 23.
On the other hand, a male screw 31 is engraved on the base of the valve stem 21, and the male screw 31 is screwed to the female screw 30 of the stem nut 23. Therefore, when the drive sleeve 22 and the stem nut 23 rotate, the valve stem 21 moves up and down by the action of the screws 30 and 31.

Furthermore, a driven gear is provided on the outer circumference of the drive sleeve 22.
32 is fitted and meshes with the drive gear 33. The drive gear 33 is connected to a drive shaft extending from a motor 34 as a rotary drive source, and rotates the drive sleeve 22 via a driven gear 32. Further, the upper load detector 26
Alternatively, the lower load detector 27 applies the load acting on the valve stem 21 via the drive sleeve 22 and the stem nut 23,
Detected as a load acting on the upper tapered roller bearing 24 or the lower tapered roller bearing 25, respectively.

The upper load detector 26 and the lower load detector 27 are judgment circuits
The detection signals from the upper load detector 26 and the lower load detector 27 are input to the determination circuit 35. The determination circuit 35 includes the upper or lower load detector 26 or
When it is determined that the load detected at 27 becomes excessive and overload acts on the valve stem 21, the motor 34
And the valve operation panel 36 stops the motor 34. These determination circuit 35 and valve operation panel 36
Function as

 Next, the operation will be described.

The driving force of the motor 34 is transmitted to the drive sleeve 22 via the drive gear 33 and the driven gear 32, and the drive sleeve 22 rotates (rotates). The rotation of the drive sleeve 22 causes the stem nut 23 to rotate (rotate).
The valve stem corresponds to the rotation direction of the stem nut 23.
21 moves up and down, and the valve element opens and closes.

If an overload acts on the valve stem 21 during the valve opening operation, the overload is applied to the lower load detector 27 via the stem nut 23 supporting the valve stem 21, the drive sleeve 22, and the lower tapered roller bearing 25. Is transmitted to
Also, if an overload acts on the valve stem 21 during the valve closing operation,
This overload is applied to the stem nut 23, drive sleeve 22
And transmitted to the upper load detector 26 via the upper tapered roller bearing 24. These lower load detector 27 and upper load detector 26 detect the transmitted overload and a detection signal is output to determination circuit 35. Judgment circuit
35 receives the detection signal of the overload, determines the abnormality, instructs the valve operation panel 36 to stop the motor, and the valve operation panel 36 executes this.

According to the first embodiment, an overload acting on the valve stem 21 is detected as an overload acting on the upper or lower tapered roller bearing 24 or 25 which directly indicates the valve stem 21. The influence is small and the overload can be accurately detected. As a result, the valve drive can be appropriately controlled, and the soundness of the valve stem 21 and the appropriate seat pressure can be achieved.

FIG. 2 is a sectional view showing a second embodiment of the valve drive control device according to the present invention. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the valve drive control device 40 according to the second embodiment, the upper tapered roller bearing 24 and the lower tapered roller bearing 25 that rotatably support the drive sleeve 22 are connected by a sleeve 41. This sleeve 41 is
21 is slidably fitted in the casing 28 in the axial direction. The drive sleeve 22 and the upper and lower tapered roller bearings 24 and 25 integrated by the sleeve 41 are supported by the casing 28 by a coil spring 42 as an elastic body, and allow the valve stem 21 to slide in the axial direction. Is done.

In the casing 28, a limit switch 43 as an overload detector is provided. When a load acts on the valve stem 21, the drive sleeve 22, the upper tapered roller bearing 24, the lower tapered roller bearing 25, and the sleeve 41 apply the urging force of the coil spring 42 by a direction and a distance corresponding to the direction and size of the load. Slide against The limit switch 43 opens and closes a contact when the sliding direction and the sliding amount of the sleeve 41 and the like reach a predetermined value, and outputs a signal to the control unit 37.

The control unit 37 detects from the limit switch 43 when an overload acts on the valve stem 21 and the slide amount of the drive sleeve 22, the upper tapered roller bearing 24, the lower tapered roller bearing 25, and the sleeve 41 increases. The motor 34 is stopped based on the signal.

Therefore, according to the second embodiment, the overload acting on the valve stem 21 can be prevented from being applied to the drive sleeve 22, the upper tapered roller bearing 24, and the lower tapered roller bearing 25.
Since it is detected as the sliding direction and the sliding amount of the sleeve 41, the influence of friction and the like is small, and the overload acting on the valve stem 21 can be accurately detected. As a result,
The valve drive can be appropriately controlled, and the soundness of the valve stem 21 and the appropriate seat pressure can be achieved.

In the second embodiment, the drive sleeve 22, the upper tapered roller bearing 24, the lower tapered roller bearing 25, and the elastic body that supports the sleeve 41 are provided as elastic bodies.
Although the coil spring 42 is described as being used, a disc spring 44 as shown in FIG. 3 may be used instead of the coil spring 42. In the case of this modification, valve control under a large load can be performed as compared with the case where the coil spring 42 is used.

FIG. 4 is a sectional view showing a third embodiment of the valve drive control device according to the present invention. In the third embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the valve drive control device 50 of the third embodiment, the valve stem 51
A valve stem base element 53 having an external thread 52, and a valve stem end element 54 connected to a valve body (not shown).
And a disc spring structure as a flexible member interposed between the valve stem base element 53 and the valve stem end element 54
55. This disc spring structure 55 is configured by combining two upper disc springs 56 and lower disc springs 57 having a truncated cone shape in a vertically symmetric manner. The male screw 52 of the valve stem base element 53 is screwed with the female screw 30 of the stem nut 23. When an overload acts on the valve stem 51 during the opening and closing operation of the valve, the upper disk spring 56 and the lower disk spring 57 having a truncated cone shape constituting the disk spring structure 55 are deformed.

Further, an upper tapered roller bearing 24 and a lower tapered roller bearing 25 supporting the drive sleeve 22 are provided.
Is directly fixed to the casing 28. Further, a light-emitting device 58 and a light-receiving device 59 as overload detectors are respectively installed on the slopes of the upper and lower disc springs 56 and 57 of the disc spring structure 55.

Light from the light emitter 58 is transmitted to the upper disc spring 56 and the lower disc spring.
The light passes through the space 57 and is received by one of the seven regions of the light receiver 59 in accordance with the amount of bending deformation of the disc springs 56 and 57. Each region of the light receiver 59 has a normal valve drive force region 60 at the center position of the light receiver 59, and a large valve drive force region 61 at the time of closing and a valve close valve at the left side in the figure of the normal valve drive force region 60. Excessive driving force region 62 and overload region 63 at the time of valve closing are sequentially arranged. Further, in the light receiver 59, a valve-opening large valve driving force region 64, a valve-opening excessive driving force region 65, and a valve-opening overload region 66 are sequentially installed on the right side in the figure of the normal valve driving force region 60. .

Of these, the valve closing overload region 63 and the valve opening overload region 66 are electrically connected to the control unit 37. When these regions 63 and 65 receive light from the light emitter 58,
The controller 37 determines that an overload has acted on the valve stem 51 and stops the motor 34.

On the other hand, the display unit 67 is provided on the casing 28 at a position where the inspector can see it. The display unit 67 is configured by, for example, a light emitting diode. This display section 67 also has seven areas 7
0,71,72,73,74,75,76, each of these areas 70-76
Are electrically connected to the respective regions 60 to 66 of the light receiver 59. When the normal valve driving force area 60 receives light, the area 70 of the display section 67 emits green light, for example, and the valve driving force large area when the valve is closed
61 and the large valve drive force region 64 when valve is open, the display
When the regions 71 and 74 of the 67 emit light, for example, yellow, respectively, and when the valve closing excessive valve driving force region 62 and the valve opening excessive valve driving force region 65 receive light, the regions 72 and 75 of the display unit 67 respectively become red, for example. Emit light. The light emission of these display units 67 is configured to maintain the light emission state at least for a time equal to or longer than the patrol interval of the inspector.

In the third embodiment, when an overload acts on the valve stem 51 during the valve closing operation, the upper disc spring 56 and the lower disc spring 57 are compressed and deformed to the position indicated by the two-dot chain line in FIG. At this time, when the light from the light emitter 58 is received in the valve overload area 63 of the light receiver 59, the controller 37 stops the motor 34. Also,
When the valve stem is opened, an overload acts on the valve stem 51, and the upper disc spring 56 and the lower disc spring 57 are tensile-deformed, so that light from the light emitter 58 is received in the overload region 66 of the light receiver 59 when the valve is opened. Also, the control unit 37 stops the motor 34.

In this manner, the overload acting on the valve stem 51 is directly detected by the light emitter 58 and the light receiver 59 as a deformation of the upper disc spring 56 and the lower disc spring 57 of the disc spring structure 55, so that the overload acting on the valve stem 51 is acted on. Overload detection can be accurately performed. As a result, the valve drive can be appropriately controlled, and the soundness of the valve stem and the appropriate seat pressure can be achieved.

Deterioration of the gland packing fixed to the valve body,
Due to the increase in frictional force between the valve body and the guide, etc.
When the valve is closed, light from the light emitter 58 emits light from the trainee 59 when the valve is closed. When the excessive force area 65 is received, the respective areas 71, 72, 74 or 75 of the display unit 67 emit light. For this reason, the inspector can visually recognize the degree of deterioration of the gland packing by visually checking the display on the display section 67, and can carry out the periodic inspection of the valve quickly and rationally.

In the third embodiment, the flexible member of the valve stem 51 has been described as the disc spring structure 55. However, the flexible member may be the plate spring structure 77 shown in FIG. . This leaf spring structure 77 is an upper leaf spring having a cross-shaped planar shape.
78 and a lower leaf spring 79 are combined. Then, the light emitter 58 is installed upward on the lower leaf spring 79, and the light receiver 59 and the display unit 67 are installed on the casing.

In the case of the leaf spring structure 77, since the upper leaf spring 78 and the lower leaf spring 79 have a cross shape, a transmission hole formed in the upper disc spring 56 of the disc spring structure 55 is not required. Further, since the light from the light emitter 58 is received by the light receiver 59 provided in the casing 28, a long transmission circuit connecting the light receiver 59 and the display unit 67 is not required.

In the third embodiment, the light-emitting device 58 and the light-receiving device 59 are installed as overload detectors on the disc spring structure 55 or the plate spring structure 77, but a limit switch may be installed instead. . This limit switch detects the amount of deformation of the disc spring component 55 or the plate spring component 77, and stops the motor 34 via the control unit 37 based on this detection signal.

〔The invention's effect〕

According to the first aspect of the present invention, the valve stem is formed by interposing a flexible member between the valve stem base element and the valve stem end element, and the inside of the valve stem raising / lowering part which is rotatably installed in the casing. The valve stem base element is screwed into the valve stem, a rotary drive source connected to the valve stem elevating unit rotates the valve stem elevating unit, and a flexible member installed on the valve stem is formed in a truncated cone shape. And a light-emitting unit provided on the inclined surface of the one disk spring, and a light-receiving unit provided on the inclined surface of the other disk spring. The light emitting unit emits light toward the space portion of the combined disc spring, and the light receiving unit receives the light to detect the amount of deformation of the flexible member,
The control unit receives the signal from the light receiving unit so that the operation of the rotary drive source can be stopped. If an overload acts on the valve stem, the overload acting on the valve stem is flexibly changed. Because it is directly detected by bending deformation of the member,
The overload can be accurately detected, and as a result, the valve drive can be appropriately controlled.

According to the first aspect of the present invention, the angle of light emission from the light emitting unit is changed by the bending deformation of the flexible member, and the overload value is quantitatively measured by shifting the light receiving position in the light receiving unit. , And both the compressive load and the tensile load in the axial direction of the valve stem can be measured.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a valve drive control device according to the present invention, FIG. 2 is a sectional view showing a second embodiment of the present invention, and FIG. 3 is a modification of the second embodiment. FIG. 4 is a sectional view showing a third embodiment of the present invention. FIG. 5 is a plan view showing a leaf spring constituting member showing a modification of the third embodiment. FIG. 6 is a conventional valve. It is a perspective view showing a drive control device. 20: Valve drive control device, 21: Valve stem, 22: Drive sleeve, 23: Stem nut, 24: Upper taper roller bearing, 25: Lower taper roller bearing,
26 …… Upper load detector, 27 …… Lower load detector, 28 ……
Casing, 30 female screw, 31 male screw, 34 motor, 35 judging circuit, 36 valve operating panel, 37 control unit,
40 ... valve drive control device, 41 ... sleeve, 43 ... limit switch, 50 ... valve drive control device, 51 ... valve stem,
53 ... valve stem base element, 54 ... valve stem end element, 55 ... leaf spring structure, 58 ... light emitter, 59 ...
Receiver 63, overload area when valve closed, 66 overload area when valve open.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-246668 (JP, A) JP-A-50-97810 (JP, A) JP-A-2-236075 (JP, A) 131573 (JP, U) Jigyo 44-11576 (JP, Y1) Jigyo 42-15493 (JP, Y1) (58) Fields investigated (Int. Cl. ⁶ , DB name) F16K 31/04 F16H 25 / 20-25/24

Claims (1)

(57) [Claims] 1. A valve stem having a flexible member interposed between a valve stem base element and a valve stem end element, and a valve stem which is rotatably mounted on a casing and internally screwed with the valve stem base element. A valve stem elevating part,
A rotational drive source connected to the valve stem elevating unit to rotate the valve stem elevating unit, and an overload detector installed on the flexible member of the valve stem and detecting an amount of deformation of the flexible member; A control unit that can receive a signal from the overload detector to stop the operation of the rotary drive source. The flexible member is provided with a disc spring formed in a truncated cone shape in a vertically symmetrical manner.
The overload detector comprises a light emitting unit provided on a slope of the one disk spring, and a light receiving unit provided on a slope of the other disk spring, and A valve drive control device characterized in that light is emitted toward a space portion of the disc spring where the two portions are combined, and this light is received by the light receiving portion.