JP2662671B2 - Motorized valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a motor-operated valve for controlling water, oil, air, steam, and other various fluids, and particularly to an emergency valve such as a power failure or an earthquake. It relates to an emergency shutoff valve or an emergency release valve that automatically returns the body to a safe position, and is widely used as a safe and fail-safe control valve in the field of automatic control. [Prior art] A motor operated valve used as a conventional technique is, for example,
As disclosed in JP-A-61-193269, a rotating shaft that can be connected to the rotating shaft of the valve is mounted in the casing, and the rotating shaft is provided with:
The inner end of the spring with the outer end fixed to the casing is fixed, and the motor stops rotating when a constant torque or more is applied to the rotor while the casing is energized. 2. Description of the Related Art A valve emergency opening / closing device is known in which a rotating shaft of a motor is fitted and connected to the rotating shaft via a one-way clutch and a speed reduction mechanism, and a casing is provided with a stopper for regulating a rotation angle of the rotating shaft. . [Problems to be Solved by the Invention] According to such a conventional electric valve, in this case, since the spring is mounted on the rotating shaft, a large load is required as a spring force. There is a drawback that the motor to be wound is inevitably increased in size and power consumption is increased. Furthermore, since the one-way clutch is adopted, the valve element rotates only in one direction, foreign matter is easily caught in the seat surface of the valve element, and the valve element cannot be reversed. There was a drawback that it could not return to the position. As another conventional technique, a ratchet gear is engaged with a reduction gear to hold a valve at a constant opening against spring force. In this case, however, the material, shape, If the engagement force is not sufficient, the durability deteriorates, so that there is a disadvantage that the size and the cost are inevitably increased. [Means for solving the problems] The present invention has been made in view of such conventional disadvantages,
Providing electric valves with fail-safe emergency opening and shut-off functions, realizing miniaturization and low price, reducing power consumption, instantaneous forward and reverse rotation, and moving to the safe position of the valve during operation An object of the present invention is to provide a motorized valve that can be automatically reset and has excellent durability. The present invention has the following features to solve the problems. That is, an electric motor 1 that generates a rotating power in response to an electric input, a reduction unit having a plurality of intermediate reduction shafts that reduce the rotation speed of the electric motor to increase the output torque, and are driven by an output shaft of the reduction unit. And a valve element for controlling the opening and closing of the fluid flow path, wherein an electromagnetically actuated electromagnetic brake for directly braking the rotating shaft of the electric motor is arranged in the electric valve, and the valve opening detection switch connects the electromagnetic brake and the electric motor to each other. A valve opening stopper for restricting the rotation angle of the output shaft of the speed reducer, a spring for constantly biasing the valve body toward the safe position of the valve, The means comprises a first gear meshing with a pinion gear of the electric motor, a second gear meshing with the first gear, and an output gear meshing with the second gear, wherein the spring is mounted on the first gear. [Operation] The electromagnetic brake 4 at the time of excitation maintains the operating position of the valve with low power consumption, and ensures durability by holding the braking surface as a contact means as a holding means. The valve opening detection switch 5 switches between the electromagnetic brake and the electric motor with a single switch. The valve opening stopper 6 stops the output shaft at the safe position of the valve and regulates the rotation of the output shaft due to the spring force. Spring 7
Is constantly biased, and is mounted on the first gear 14 which meshes with the pinion gear of the electric motor as a speed reduction means, so that the reduction ratio can be used so that the spring force can be reduced with a small load, and the spring can be downsized. In addition, the motor that winds the spring can be downsized, and the power consumption can be reduced. [Embodiment] One embodiment of the present invention will be described with reference to FIGS. 1 to 5. A fluid passage A is bored inside a valve body 10, and a ball-shaped valve body 3 corresponding to a valve seat. Are arranged so as to be freely slidable.
A valve stem 11 integrally connected to the valve body 3 is rotatably disposed with respect to the valve body 10 and the actuator body 12, and the valve stem also serves as an output shaft of the reduction means 2, and an output gear 13 is fixed thereto. You. The deceleration means includes a first deceleration shaft 16 and a second deceleration shaft 17 that support the first gear 14 and the second gear 15, respectively. The first deceleration shaft 16 has a spring that constantly presses and biases the valve body to a safe position. 7 is attached. That is, the spring 7 was mounted on the first gear 14. The spring 7 is a coil spring, and is preferably a leaf spring coil spring. This is because a sufficient spring speed can be ensured by reducing the spring constant. A valve opening stopper 6 made of a screw member is screwed to the actuator body 12 to restrict the rotation of the output shaft beyond a certain angle. Also, in the actuator body 12,
A valve opening switch 5 that operates at a constant opening is arranged, and its operating position is set by a cam 18 fixed to an output shaft. A pinion gear 20 and a brake plate 21 are directly fixed to a rotation shaft 19 of the electric motor 1 mounted on the speed reduction means, and a brake shoe 22 of the electromagnetic brake 4 when excited is arranged in contact with the brake plate. The electromagnetic brake 4 is of a normally open type, in which the movable iron core 23 is attracted when energized, and the brake shoe 22 is pressed against the brake plate 21 to generate a braking force. Next, the operation of the embodiment will be described. FIGS. 1 to 3 show a valve closed state (safety position), and FIGS. 4 to 5 show a valve open state. When the valve is closed, the output gear 13 is
The valve opening degree switch 5 connects the power source to the electric motor side while being rotated by receiving the force of the rotation of the valve and contacting the stopper 6 when the valve is closed. At this time, when the operation switch 24 of the double contact is closed and the power is turned on to the electric motor, the output gear 13 rotates in the direction of arrow B and the valve opens, and when fully opened, the cam 18 turns the valve opening switch 5.
To switch the power supply to the electromagnetic brake side. Therefore,
The valve holds the fully open state by the holding force of the electromagnetic brake,
At this time, the spring 7 is always wound up and always has a force in the valve closing direction. Then, open the operation switch 24 or
Alternatively, at the time of a power failure, the power supply to the electromagnetic brake is interrupted, and the output gear 13 operates in the direction of arrow A, that is, the valve closing direction by the force of the spring 7, and comes into contact with the valve opening stopper 6 to close the valve closing position ( To the safe position). Although the embodiment shows the emergency shut-off valve (the safety position is the valve closed position), it can be changed to the emergency open valve (the safety position is the valve open position), and the reduction means is a chain, belt, pulley,
It can be replaced with a worm gear. The ball valve of the embodiment can be replaced and applied to a butterfly valve, a disc valve, a gate valve, and a diaphragm valve. [Effect of the Invention] Since the minimum load portion of the speed reduction means is stopped by the electromagnetic brake at the time of excitation, the speed reduction means can be stopped against a large spring force with a small stopping power, and the surface contact brake can be used. Because of this, the durability was improved and the size was reduced.
Further, when the motor is stopped, the power supply to the electric motor is cut off, and the power supply is performed only by the brake with low power consumption, so that a power saving effect can be expected. Furthermore, since switching between the electric motor and the electromagnetic brake is made possible with a single switch, it is possible to reduce the size at low cost.
Since only one switch adjustment is required, maintainability and assemblability were improved. The valve opening stopper makes it possible to secure the stop of the valve at a safe position and make fine adjustments. Since the spring was mounted on the first gear of the speed reduction means, the valve rod could be rotated using the reduction ratio even if the spring load was small, and the size and cost of the spring could be reduced. The valve body can be rotated forward and backward, there is little foreign matter biting on the seat surface, and instant reversal operation is possible during operation, so that safety can be restored immediately. The motor-operated valve according to the present invention can be used as a fail-safe emergency shut-off valve and an emergency release valve, and can achieve a large size, a low price and a high durability.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of a motor-operated valve according to the present invention. FIG. 1 is a longitudinal sectional view, FIG. 2 and FIG. 4 are explanatory views showing different operation states, FIG. FIG. 5 is an electric circuit diagram showing different operation states. DESCRIPTION OF SYMBOLS 1 ... Electric motor, 6 ... Valve opening stopper 2 ... Deceleration means, 7 ... Spring 3 ... Valve 4 ... Electromagnetic brake 5 ... Valve opening switch

Claims (1)

(57) [Claims] An electric motor 1 that generates a rotating power in response to an electric input, a reduction unit 2 having a plurality of intermediate reduction shafts for reducing the rotation speed of the motor and increasing an output torque, and driving by an output shaft of the reduction unit. And a valve element 3 for controlling the opening and closing of the fluid flow path, an electromagnetic valve 4 at the time of excitation that directly brakes the rotating shaft of the electric motor is disposed in the electric valve having the valve body 3, and the electromagnetic brake and the electric motor are connected to each other by a valve opening degree. A detection switch 5 selectively connects to a power source, a valve opening stopper 6 for restricting the rotation angle of the output shaft of the speed reducer, and a spring 7 for constantly biasing the valve body toward the safe position of the valve. , Wherein the speed reducing means includes a first gear that meshes with a pinion gear of the electric motor.
A second gear 15 meshing with the first gear;
An electric valve comprising an output gear 13 meshed with a gear, wherein the spring 7 is mounted on a first gear 14. 2. The motor-operated valve according to claim 1, wherein the spring (7) is a plate-shaped coil spring.