JPH0828733A - Valve driving device with automatic return mechanism - Google Patents

Abstract

PURPOSE:To properly close a valve from the fully opened state to the stop of current supply for stabilizing the valve for a long period in an automatic return valve driving device reversed by force accumulated in a spring in the stop of current supply. CONSTITUTION:An automatic return valve driving device having a motor 4, a reduction gear 7 and output shaft 6 for reducibly transmitting the rotational output of the motor 4 in the current supply, a spring 9 having energy accumulated by a rotational force and a mechanism for stopping the rotation of the motor 4 at a fixed position and holding electrically the accumulated energy of the spring 9 so as to be reversed by the spring accumulated energy in the stop of the current-supply is provided on either the output shaft 6 of the motor or the reduction gear 7 having larger rotation in the reverse rotation with a hysteresis brake mechanism.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve drive device having a mechanism for rotating a valve in one direction by a motor and automatically returning the valve in the other direction when energization is stopped.

[0002]

2. Description of the Related Art Generally, a valve drive device with an automatic return mechanism stores a motor and a reduction gear that reduces the rotation output of the motor and transmits the rotation output to the output shaft, and a motor rotation output from the reduction gear via the output shaft. Have a mainspring. In this drive device, first, the motor is driven to urge the mainspring, and at the same time, the output shaft is rotated in one direction (for example, rotated in the valve opening direction; hereinafter referred to as valve opening rotation). The valve opening rotation of the output shaft is brought to a fully opened state by the opening side stopper mechanism and completed. The holding of the fully opened state, that is, the state of winding the mainspring is performed electrically. Thereafter, when the energization is stopped in this fully open state, the winding-holding state of the mainspring is released, and the output shaft reverses in the other direction (for example, rotates in the valve closing direction due to the stored force of the mainspring. ) Will be done. At this time, the rotor of the motor is accelerated and rotated by the reduction gear. The valve closing rotation of the output shaft is completed by the closing side stopper mechanism, and the fully closed state is achieved. As described above, in the conventional valve drive device with automatic return mechanism, the rotor is accelerated and rotated by the power storage force of the mainspring through the reduction gear at the time of valve closing rotation, and finally the rotation speed becomes very large. None had a mechanism to control the number. Further, as another conventional example, a brake or a clutch for cutting off the supply of power to the motor when the output shaft is fully opened and electrically holding the mainspring in a wound state is provided.

[0003]

Among the above-mentioned prior arts, the one in which the output shaft, the reduction gear, and the rotor are simultaneously reversed by the stored force of the mainspring finally has a very high rotational speed. Was there. Therefore, the life of the reduction gear and the motor are adversely affected, and noise is generated. Further, in the case where the brake and the clutch are provided, when the energization is stopped from the fully open state, the clutch is switched and the brake is opened, and at the same time, the output shaft is rapidly closed and rotated by the stored force of the mainspring, and the valve (not shown) is shown. Close). That was the cause of the water hammer. SUMMARY OF THE INVENTION It is an object of the present invention to provide a valve drive device with an automatic return mechanism, which has a long life, low noise, and is free from the risk of water hammer when the valve is closed and rotated at an appropriate speed when the energization is stopped from the fully open state.

[0004]

The present invention has been made to achieve the above object. That is, a motor, a reduction gear and an output shaft for decelerating and transmitting a rotation output by the motor when energized, and a mainspring that stores energy by the rotation force.
In an automatic return valve drive device that has a mechanism that electrically stops the power storage force of the mainspring by stopping the rotation of the motor at a fixed position, and that reverses by the power storage force of the mainspring when the energization is stopped,
A hysteresis brake mechanism is attached to either the motor output shaft or the reduction gear whose rotation speed is high during reverse rotation to prevent an increase in the rotation speed of the rotor during reverse rotation.

[0005]

When the motor is driven, the output shaft opens the valve through the reduction gear and at the same time urges the mainspring. The valve opening rotation of the output shaft is brought to a fully opened state by the opening side stopper mechanism and completed. In the fully opened state, the electric holding mechanism electrically holds the power storage state of the mainspring. Then, when the energization is stopped, the electrical holding mechanism is opened, and the output shaft starts the valve closing rotation by the stored force of the mainspring. At the same time, the permanent magnet or conductor of the hysteresis brake starts accelerating rotation via the reduction gear, and a rotating magnetic field is formed between the permanent magnet and the fixed permanent magnet. The rotating magnetic field generates an eddy current in the conductor in a direction that suppresses rotation. That is, after the valve closing rotation starts,
The number of revolutions increases rapidly, but as the number of revolutions increases, this eddy current also increases and the force that suppresses the number of revolutions becomes stronger, and the number of revolutions stabilizes in a balanced state. Therefore, it is possible to prevent an increase in the valve closing speed. The valve closing speed is determined by the gap A between the conductor and the permanent magnet, the strength of the permanent magnet, and the material of the conductor. Normally, the smaller the gap A between the conductor and the permanent magnet, and the stronger the strength of the permanent magnet, the slower the valve closing speed, and the valve closing time also becomes slower accordingly. become.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG.
2 is a vertical sectional view showing an embodiment of the present invention. First, the configuration of the first embodiment will be described with reference to FIG. 1. A housing 1 is attached with a base 2 and a cover 3, a motor 4 is fixed on the base 2, and the rotation output of the motor 4 is It is decelerated by a reduction gear 7 composed of a gear fixed to a rotary shaft 5 of a motor 4, a gear shaft having large and small gears, and a gear fixed to an output shaft 6, and is transmitted to the output shaft 6. The output shaft 6 has a valve body (not shown) at the lower end.
Has an engaging portion that engages with, and receives the rotational output of the motor 4 to drive the valve element in the valve opening direction. On the other hand, a stop plate 8 is fixed to the output shaft 6, and the other end of a mainspring 9 having one end fixed to the base 2 is fixed to the stop plate 8. The mainspring 9 is the rotating shaft 5 of the motor 4 or the reduction gear 7.
It can also be attached to the gear shaft of. An open side stopper 10 is also fixed on the base 2 and cooperates with the stop plate 8 to prevent the output shaft 6 from rotating beyond the fully open position. A rotating shaft 5 above a rotor (not shown) of the motor 4 has a motor housing 12 made of a non-magnetic conductor such as aluminum die cast and a permanent magnet 11 with a gap A therebetween.
Is attached and rotates with the rotating shaft 5. In addition,
The permanent magnet may be attached to the rotating shaft 5 on the lower side so as to face the housing 1 or the base 2.

Next, the operation of the first embodiment will be described. When the motor 4 is driven, the output shaft 6 opens the valve via the reduction gear 7 and at the same time urges the mainspring 9. In the valve opening rotation of the output shaft 6, the stop plate 8 contacts the opening side stopper 10, the valve opening rotation is completed, and the valve is fully opened. In the fully open state, the motor 4 is in the holding state, and the power storage state of the mainspring 9 is electrically held. Then, when the energization is stopped, the holding state of the motor 4 is released, and the stored force of the mainspring 9 causes the output shaft 6 to start the valve closing rotation. At the same time, the motor rotating shaft 5 and the permanent magnet 11 start accelerated rotation via the reduction gear 7 to generate a rotating magnetic field, and the rotating magnetic field causes the permanent magnet 11 to rotate in the motor housing 12 made of a non-magnetic conductor. Eddy current is generated in the suppressing direction. Rotor and permanent magnet 11
The rotational speed increases rapidly after the start of the valve closing rotation, but the eddy current also increases as the rotational speed increases, and the force for suppressing the rotational speed becomes stronger, and the rotational speed stabilizes in a balanced state. That is, it is possible to prevent an increase in the maximum valve closing speed. Here, the maximum valve closing speed is determined by the motor housing 12 and the permanent magnet 11
Since it is determined by the size of the gap A, the strength of the permanent magnet 11, and the material of the motor housing 12, the desired valve closing speed and valve closing time may be set by adjusting these factors.

FIG. 3 shows an actual measurement example of the operation and effect when the above-described present invention is used. In the figure, the vertical axis represents the rotational speed of the rotating shaft of the motor 4, and the horizontal axis represents the time axis, which shows the time until the rotating shaft becomes unloaded and decays, and the valve closing time. For example, To is a valve closing time without a hysteresis brake, TA2 is a valve closing time with a hysteresis brake and a clearance A = 2 mm, and TA1 is a valve closing time of A = 1 mm. First, when there is no hysteresis brake, the number of rotations of the motor shaft draws a steep curve and reaches the valve closing in a short time. On the other hand, in the case of the type with a hysteresis brake, as the gap A is reduced to 2 mm, 1 mm, and 0.5 mm, the rotation speed is suppressed and the valve closing time is lengthened, and the effect of the present invention is also exhibited. Recognize. still,
The gap A was carried out for 8 types from 2 mm to 0.3 mm, and a representative example is shown.

Next, a second embodiment will be described with reference to FIG. In FIG. 2, parts given the same reference numerals as those in FIG. 1 are parts having the same functions as in the first embodiment, and explanations thereof are omitted. In this embodiment, a non-magnetic rotating conductor plate 13 is fixed to the rotating shaft 5 of the motor 4 and is fixed to the motor housing 12 to be a permanent magnet.
14 is attached. In this embodiment, the rotating conductor plate 13 is accelerated and rotated in the magnetic field of the fixed permanent magnet 14 with the valve closing rotation of the output shaft 6, and an eddy current is generated in the rotating conductor plate 13 in a direction to suppress the rotation. The same effect as the example is obtained.

[0010]

According to the present invention, by providing a hysteresis brake mechanism on either the motor output shaft or the reduction gear or the output shaft gear, the valve is closed and rotated at an appropriate speed from the fully opened state when the energization is stopped, and the long life, It is possible to provide a valve drive device with an automatic return mechanism that has low noise and is free from the risk of water hammer.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a valve drive device with an automatic return mechanism of the present invention.

FIG. 2 is a vertical sectional view showing another embodiment of the present invention.

FIG. 3 is an example of actual measurement showing the relationship between motor shaft rotation speed and time when the present invention is used.

[Explanation of symbols]

 1 ... Housing 2 ... Base 3 ... Cover 4 ... Motor 5 ... Rotating shaft 6 ... Output shaft 7 ... Reduction gear 8 ... Stop plate 9 ... Mainspring 10 ... Open side stopper 11 ... Permanent magnet 12 ... Motor housing 13 ... Rotating conductor plate 14 … Fixed permanent magnet

Claims (3)

[Claims] 1. A motor, a reduction gear and an output shaft for decelerating transmission of rotation output by the motor when energized, a mainspring accumulated by the rotational force, and rotation of the motor at a fixed position to electrically stop the motor. In an automatic return valve drive device that has a mechanism that electrically holds the power of the mainspring and that reverses by the power of the mainspring when the power supply is stopped, either the motor output shaft or the reduction gear with a large number of revolutions during reverse rotation A valve drive device with an automatic return mechanism, which is provided with a hysteresis brake mechanism. 2. The hysteresis brake is characterized in that a permanent magnet is attached to a motor shaft or a reduction gear, and a conductor is fixed in opposition to the permanent magnet.
The valve drive device with the automatic return mechanism described. 3. The hysteresis brake is characterized in that a conductor is attached to a motor shaft or a reduction gear and a permanent magnet is fixed against the conductor so as to be opposed thereto.
The valve drive device with the automatic return mechanism described.