JPH05332467A - Manual operation device for actuator for valve - Google Patents

Abstract

PURPOSE:To obtain a manual operating device which can be revolution-operated in any direction and permits the reciprocating operation and the continuous operation in the same direction by operating a knob, shifting an engagement gear against the springy force of a spring, and releasing the engagement with a fixed gear. CONSTITUTION:In the ordinary time, a valve is opened by revolving an output shaft 3 through an engagement gear 6 and a fixed gear 5 by the rotary shaft 4a of a motor 4. At the same time, a limit switch 9 is operated at the opening/ closing position of the valve by a cam 10 fixed on the output shaft 3, and the motor 4 is controlled. When manual operation is carried out in case of electric failure, a knob 8 is operated, and the engagement with the fixed gear 5 is released by pushing down the engagement gear 6 against the springy force of a spring 7. Manual operation is carried out by applying a spanner, etc., at the manual operation edge 3a of the output shaft 3. At this time, the output shaft 3 can be arbitrarily turned in any direction, and can be returned to the power operation indepedently of the opening/closing state of the valve.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manual operating device for a valve actuator, and more particularly to a device for operating a valve shaft of a valve such as a ball valve through a reduction mechanism using an electric motor or an air motor as a power source. The present invention relates to a manual operation device provided on an actuator.

[0002]

2. Description of the Related Art When an electric motor or an air motor is used as a power source and a valve operated through a reduction mechanism is cut off for some reason when electricity or compressed air, which is the power source, is cut off,
It becomes necessary to operate manually. In this case, it is convenient to directly manually operate the output shaft directly connected to the valve shaft by using a spanner or the like. However, the output shaft is acceleratingly connected to the rotation shaft of the motor through the gear train, and operating the output shaft not only operates the valve but also rotates the gear train and the motor that require large torque. As a result, manual operation is extremely difficult. Further, when the motor is a brake motor, it is impossible to manually operate the output shaft. Therefore, in this type of reduction mechanism, it is necessary that the output shaft is not connected to the gear train during manual operation, and various devices for this purpose have been conventionally provided.

In the structure disclosed in Japanese Utility Model Laid-Open No. 49-35022, a one-way rotary clutch is mounted between the output shaft and a gear mounted on the output shaft, and the output shaft is manually operated in a direction in which it can be rotated by a speed reducer. The output shaft does not rotate the gear train during operation. With this structure, the rotational operation during manual operation is only one direction, and reciprocal operation is not possible, which is inconvenient for some valves.
Further, there is a problem that the one-way rotation clutch is easily worn or broken and lacks reliability.

In the structure disclosed in Japanese Utility Model Publication No. 55-693, an output shaft and a gear inserted or concentric with the output shaft are connected by a connecting pin and a stopper, and the output shaft is manually operated in a direction to be rotated by a speed reducer. When operated, the connecting pin and the stopper are separated from each other so that the output shaft does not rotate the gear train. In this structure, the start stroke of the manual operation is limited to one direction, the next stroke is limited to the opposite direction to the previous stroke, and the stroke direction cannot be freely selected. Further, unless the rotational position of the output shaft after the manual operation is completed is returned to the position where the manual operation is started, the first stroke of the next power operation is unrelated to the opening / closing of the valve, which is inconvenient. Further, there is a problem that the contact area between the connecting pin and the stopper is relatively small, and it is liable to suffer wear or failure and lack reliability.

[0005]

The conventional manual operation device of the present invention is limited in the rotation direction of the manual operation,
This is to solve the problem that wear and failure easily occur.

[0006]

In order to solve the above-mentioned problems, the manual operating device of the present invention is constructed as follows.
In a valve actuator having a mechanism in which a gear train is provided between an output shaft having a manually operated end at an outer end and a rotation shaft of a motor, the actuator being connected to a fixed gear fixed to the output shaft. The engaging gear that transmits the rotational force is always kept in the axial engaging position by the elastic force of the spring. Against the elastic force of the spring, disengage from the fixed gear by moving it in the axial direction, manually operate the valve with the manually operated end, and when the knob operation is stopped, the engaging gear moves together with the knob into the spring elastic force. It is configured to return by the force of force.

In this case, the output shaft may be formed integrally with the valve shaft of the valve, and it is preferable that a cam for activating a limit switch for motor control is fixed to the output shaft.

[0008]

Since the manual operating device of the present invention is constructed as described above, the rotation of the rotating shaft of the electric motor or the air motor is always transmitted to the engaging gear through the gear train while decelerating and engaging with the engaging gear. The output shaft is transmitted to the fixed gear and the valve shaft of the valve is rotated to open and close the valve. A cam fixed to the output shaft actuates a limit switch at the valve opening and closing positions to control the motor.

When a manual operation is performed due to a power failure or the like, the knob is operated to move the engaging gear in the axial direction against the elastic force of the spring to disengage the fixed gear from the outside of the output shaft. Manual operation of the end Put a spanner on the end to perform manual operation. In this case, the output shaft can be arbitrarily rotated in any rotation direction. In addition, it is possible to return to the power operation which will be described below, in a state where the valve is opened or closed by a manual operation.

Next, when the operation of the knob is stopped, the engagement gear returns to the engagement position where it engages with the fixed gear by the elastic force of the spring together with the knob. In this case, when the relational position between the teeth of the fixed gear and the teeth of the engaging gear cannot be immediately engaged, the both gears can be engaged when the engaging gear slightly rotates by the next power operation. Then, the engaging gear moves to the engaging position by the elastic force of the spring, and the correct engagement state is achieved.
When the output shaft is formed integrally with the valve shaft of the valve, there is no play between the output shaft and the valve shaft, and the open / close position is maintained correctly.

[0011]

FIG. 1 is a partial sectional view of a valve actuator provided with an embodiment of a manual operating device of the present invention.
It shows the normal state. Further, FIG. 2 is a partial cross-sectional view showing a state in which a knob of the reduction mechanism of FIG. 1 is operated to perform a manual operation. In addition, in order to make both the cross-sectional views easy to understand, all the axes are developed so as to be arranged on the same cross section. 1 and 2, 1 is a valve actuator, 1a is an actuator casing, 2 is a manual operation device, 3 is an output shaft, 4 is a motor, 5 is a fixed gear, 6 is an engagement gear, 7 is a spring, and 8 Is a knob, 9 is a limit switch,
10 is a cam.

The output shaft 3 is directly connected to the valve shaft 11 in the lower part of the drawing, has a manually operated end 3a at its outer end, and has a fixed gear 5 fixed thereto. The valve shaft 11 is a ball valve (not shown),
It is connected to a valve body such as a butterfly valve, and the valve body is opened and closed by rotating the valve shaft 11. In FIG. 1, the engagement gear 6 is pushed up by the elastic force of the spring 7 and is engaged with the fixed gear 5. The knob 8 is also pushed up together. In FIG. 2, the engagement gear 6 is moved downward by compressing the spring 7 by pushing down the knob 8, and the engagement with the fixed gear 5 is disengaged. Cam 10
Is fixed to the output shaft 3, and when the output shaft 3 rotates to the valve opening and valve closing positions, the limit switch 9 is operated to control the motor 4.

Next, the operation will be described based on the embodiment shown in FIGS. 1 and 2. In the normal state shown in FIG. 1, the rotation of the rotating shaft 4a of the motor 4 is transmitted to the engaging gear 6 while decelerating through the gear train shown in the figure, and is transmitted to the fixed gear 5 that engages with the output shaft. 3 is rotated and the valve shaft of the valve is rotated to open the valve. The cam 10 fixed to the output shaft 3 operates the limit switch 9 at the valve open and valve close positions to control the motor 4.

When a manual operation is performed due to a power failure or the like, the knob 8 is pushed down as shown in FIG. 2 to move the engaging gear 6 downward against the elastic force of the spring 7 and the fixed gear. 5
With this state, the manual operation end 3a at the outer end of the output shaft 3 is hooked with a wrench or the like to perform the manual operation. in this case,
The output shaft 3 can be arbitrarily rotated in any rotation direction. In addition, it is possible to return to the power operation described below in a state where the valve is opened or closed by a manual operation.

Next, when the pushing operation of the knob 8 is stopped,
The engagement gear 6 returns to the engagement position where it engages with the fixed gear 5 by the elastic force of the spring 7 together with the knob 7, that is, the state shown in FIG. In this case, when the relative positions of the teeth of the fixed gear 5 and the teeth of the engagement gear 6 cannot be immediately engaged, when the engagement gear 6 is slightly rotated by the next power operation, both gears 5 and 6 are The engaging gear 6 is brought into the engageable state, the engaging gear 6 is moved to the engaging position by the elastic force of the spring 7, and the proper engaging state shown in FIG. 1 is obtained.

No matter how the engagement position between the fixed gear 5 and the engagement gear 6 is changed by manual operation, the limit switch 9 controls the motor 4 according to the rotational position of the output shaft 3, that is, the opening / closing position of the valve. , Always accurate. When the output shaft 3 is formed integrally with the valve shaft of the valve, there is no play between the output shaft 3 and the valve shaft, and the open / close position is maintained correctly.

[0017]

As described above, the manual operation device of the present invention is not limited to one direction of rotation for manual operation, and can be operated in any direction. Also, reciprocating operation and continuous operation in the same direction are possible. Further, in the valve actuator provided with the manual operation device of the present invention, the relationship between the limit switch and the cam is not affected by the switching of the manual operation and the power operation, and there is a play between the output shaft and the valve shaft. Since it does not occur, the motor can always be controlled accurately. Further, the manual operating device of the present invention has a simple structure, can be manually operated from the outside of the casing, and is highly reliable without being worn or broken.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a valve actuator provided with an embodiment of a manual operating device of the present invention.

FIG. 2 is a partial cross-sectional view similar to FIG. 1 in which a knob of the manual operation device of FIG. 1 is pushed down to perform a manual operation.

[Explanation of symbols]

 1 Valve Actuator 1a Casing 2 Manual Operating Device 3 Output Shaft 3a Manual Operating End 4 Motor 4a Rotating Shaft 5 Fixed Gear 6 Engaging Gear 7 Spring 8 Knob 9 Limit Switch 10 Cam 11 Valve Shaft

Claims (1)

[Claims] 1. A valve actuator having a speed reduction mechanism, wherein a gear train is provided between an output shaft having a manually operated end at an outer end and a gear train connected to a valve shaft of the valve. The engaging gear that engages with the fixed gear fixed to the shaft and transmits the rotational force is always kept at the engaging position in the axial direction by the elastic force of the spring and protrudes to the outside of the reduction mechanism during the manual operation. Operate the knob to move the engaging gear in the axial direction against the elastic force of the spring to release the engagement with the fixed gear, and manually operate the valve with the manual operation end to stop the knob operation. A manual operating device for a valve actuator, characterized in that the engaging gear and the knob are configured to return together with the elastic force of a spring.