JPH0650640Y2 - Shutter weight drop device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an electric shutter that opens and closes a building opening, and in particular, when the shutter curtain is opened, power is supplied from an alternating current to the electric motor that drives the shutter curtain. The present invention relates to a self-weight lowering device for a shutter in which control power is induced in a motor by a shutter curtain that drops by its own weight when switched to direct current, and an increasing descent rate of the shutter curtain is suppressed.

[Prior Art] Conventionally, in an electric shutter in which a shutter curtain is wound up by a driving force of a three-phase AC induction motor and the shutter curtain is lowered by its own weight of a hanging portion of the shutter curtain, acceleration of gravity is caused when the weight is lowered. As a result, the descending speed gradually increases and the impact of the shutter curtain when landing becomes large, and there is a risk that the shutter curtain may be damaged or that an object or a person may be caught during the descending.

Therefore, it has been proposed that the shutter opening / closing device incorporates a governor so that the descent speed of the shutter curtain is controlled to be constant.

[Problems to be Solved by the Invention] By the way, the conventional governor is a so-called mechanical governor that generates a frictional braking force by utilizing a rotating centrifugal force, and thus is easily worn and poor in durability. Not only does it have the disadvantages specific to the governor, but in order to accommodate various types of shutter curtains of different weights, it is necessary to change the braking capacity of the governor one by one, resulting in complicated adjustment work. It was something that had.

The present invention has been made in view of the above circumstances to solve the conventional drawbacks, and the purpose thereof is to:
Since there is no worn part, it is possible to suppress an increase in the descent rate of the shutter curtain without causing functional deterioration over time, and to maintain the DC power supply state from the start of the descent of the shutter curtain to the landing. Therefore, the present invention aims to provide a self-weight lowering device for a shutter that can perform a smooth and reliable closing operation.

[Means for Solving the Problems] In order to solve the problems, the technical means adopted by the present invention are:
The shutter of the electric motor is connected to a three-phase AC induction motor that winds up and raises the shutter curtain so that the supply line of the DC power supply can be switched between two lines of the AC power supply line connected to the electric motor and another line. When the shutter is not driven in the open state, it is linked to the switching from the AC power supply side to the DC power supply side, the motor is driven in reverse by the self-weighting of the shutter curtain, and the self-weight is generated by the electric power induced in the motor by the reverse driving. The feature is that the descent speed of the shutter curtain is controlled from the start of descent to the landing.

[Advantage of the Invention] Therefore, according to the present invention, when the motor is not driven, the AC power supply is switched to the DC power supply, the DC current is supplied to the temporary winding of the motor, and at the same time, the shutter curtain is The motor starts to fall by its own weight, and the fixed magnetic field generated in the stator of the motor causes the above-mentioned motor to act as an AC generator. The natural increase in the descent rate of the shutter curtain can be continuously suppressed from the start of the descent to the landing, and the impact at the time of landing can be mitigated, improving the durability of the shutter device. Can be made.

[Embodiment] The configuration of the present invention will be described in detail with reference to an embodiment shown in the drawings.

FIG. 1 is a control circuit diagram of the shutter of the present invention, and FIG. 2 is a vertical cross-sectional view of the shutter. The shutter of the present invention is a shutter horizontally provided above the opening 1 as shown in FIG. A shutter curtain 4 wound around a winding drum 3 inside
Further, the winding drum 3 is connected to the three-phase AC induction motor 10 of the electric switch 5 in the shutter case 2 via the chain 6 in a constantly linked state, and the shutter curtain 4 is wound up by the electric motor 10. The lowering of the shutter curtain 4 is performed by a driving force while the rotor of the electric motor 10 is driven to reversely rotate the winding cylinder 3 which is reversely rotated by the weight of the shutter curtain 4.

Explaining in more detail with reference to the control circuit diagram, in the three-phase AC induction motor 10, the input terminals U, V and W are provided with 200V three-phase AC power supply 11 with the R, S and T lines being the main switches. 12 and an electromagnetic contactor 14 for raising, and at the same time, the drive shaft of the electric motor 10 is braked at a raised position when the shutter curtain 4 is fully opened and at an arbitrary position when an emergency stop is performed. An electromagnetic brake 13 is attached, and power is supplied to the electromagnetic brake 13 via a first electromagnetic contactor 15 for shutter braking, which is a three-phase AC power supply.
It is designed to be branched from 11 R and T lines.

Further, the R, S, and T lines of the three-phase AC power supply 11 are provided with a reverse phase prevention relay 16, an accident prevention switch 18, and an emergency stop push button 19.
The operation circuit 17 is connected via the, and the output side of the operation circuit 17 is connected to the T line of the three-phase AC power supply 11 via the temperature safety switch 30 and the electric changeover switch 31. The operation circuit 17 is used to perform the raising and lowering operation.

The operation circuit 17 is configured by connecting a shutter opening push button 20 having a self-holding contact 21 and a shutter closing push button 22 having a self-holding contact 23 in parallel.
A shutter closing circuit breaking relay 24, the coil 25 and an upper limit switch 28 are connected in series while the shutter is being opened, and the shutter closing push button 22 has a shutter opening circuit breaking relay 26, a coil 27 and a coil 27. The lower limit switch 29 is connected in series.

Reference numeral 32 denotes a dynamic braking circuit branched and connected in parallel to the input terminals U, V, W of the electric motor 10. The dynamic braking circuit 32 includes connecting wires extending from the input terminals U, V, W. , The shutter braking second electromagnetic contactor 33 is connected to the battery 34, the two terminals U and V are commonly connected to one output side of the battery 34, and the other one terminal W is the battery. It is connected to the other output side of 34.

In the above structure, when the shutter release push button 20 is pressed, the shutter raising electromagnetic contactor 14 is turned on, the braking first electromagnetic contactor 15 is turned off, and the braking second electromagnetic contactor 33 is turned off. The shutter curtains 4 start to rise by switching accordingly. When the shutter curtain 4 reaches the opening upper limit position, the upper limit switch 28 is actuated, the opening operation portion of the operation circuit 17 is released, and the shutter raising electromagnetic contactor 14 is turned off to the electric motor 10. AC power supply is stopped and the first electromagnetic contactor for shutter braking 15
Is turned on, and the electric motor 10 is held in the open position by the electromagnetic brake 13.

Next, when the push button 22 for closing the shutter is pressed, the electromagnetic contactor 14 for raising the shutter remains off and the electric motor 10
Holds the non-driving state, while the second electromagnetic contactor 33 for shutter braking is turned on, the battery of the dynamic braking circuit 32
A direct current is supplied from 34 to the primary winding of the electric motor 10, and the first electromagnetic contactor 15 for shutter braking is switched off.
The braking of the electromagnetic brake 13 is released, the electric motor 10 is in a free rotation state, and the shutter curtain 4 begins to descend while reversing the rotor of the electric motor 10 due to the weight of the hanging portion.

At this time, a fixed magnetic field is generated in the stator of the electric motor 10 by supplying a direct current, and the electric motor 10 itself acts as a rotating armature type AC generator, and a multi-phase winding is formed in the secondary winding of the rotor. A short-circuit current flows and a braking torque is generated in the direction opposite to the rotation direction of the rotor due to the drop of the weight of the shutter curtain 4, and the shutter curtain 4 is worn from the start of the drop of its own weight due to the braking torque that opposes the rotation direction of the rotor. Until reaching the floor, the accelerating increase in the descent rate is suppressed, and the descent is performed while maintaining a constant descent rate. After that, when the shutter curtain 4 reaches the closing lower limit position, the lower limit switch 29 is actuated, the closing operation portion of the operation circuit 17 is released, and the shutter curtain braking second electromagnetic contactor 33 of the dynamic braking circuit 32. Is turned off, and thus the shutter returns to the standby state for the opening operation.

Therefore, the shock of the shutter curtain 4 at the time of landing is mitigated to prevent damage such as damage to the shutter curtain 4 or the intrusion of an object or a person while descending, and a smooth and reliable shutter. The closing operation can be performed.

[Effects of the Invention] In summary, the present invention provides a three-phase AC induction motor that winds up and raises a shutter curtain, in which a DC power supply line is connected to two lines of an AC power supply line and another line. Switchably connected between the two, and when the motor is not driven in the shutter open state, it is linked to switching from the AC power supply side to the DC power supply side, and the motor is driven in reverse by the weight drop of the shutter curtain. The descent speed of the shutter curtain is controlled from the start of descent to the floor by the generated power induced in the electric motor by the reverse rotation drive, so that the following remarkable operational effects are achieved.

Although the shutter can be closed by the same closing operation as before, braking force can be continuously applied to the shutter curtain during descent from the start of descent to the landing. The impact upon landing can be mitigated to prevent accidents such as breakage of the shutter curtain or pinching of an object or a person while descending, and the shutter curtain can always be safely lowered.

When the shutter curtain falls by its own weight, the AC power to the electric motor is cut off, so that the malfunction can be completely wiped out, and the safety when the shutter is closed can be greatly improved.

If the AC power is cut off during a disaster such as a fire or an earthquake, the shutter curtain will automatically switch to its own weight drop state regardless of whether the shutter curtain is moving up or fully open. It can be closed promptly to prevent damage from disasters, spread of fire, etc. In addition, a DC power supply provided separately from the AC power supply applies braking force to the continuously falling shutter curtain. As a result, the shutter curtain can be safely lowered at all times as in normal times.

It has extremely useful practical effects such as.

[Brief description of drawings]

1 shows an embodiment of a device for lowering the weight of a shutter according to the present invention. FIG. 1 is an overall longitudinal sectional view of the shutter, and FIG. 2 is a control circuit diagram of the shutter. In the figure, 1 ... Opening part, 3 ... Winding cylinder, 4 ... Shutter curtain, 6 ...
Chain, 10 ... Three-phase AC induction motor, 11 ... 200V three-phase AC power supply, 13 ... Electromagnetic brake, 14 ... Shutter lifting electromagnetic contactor, 15 ... Shutter braking first electromagnetic contactor, 17 ... Operating circuit, 20 ... A shutter opening push button, 22 ... Shutter closing push button, 28 ... Upper limit switch, 29 ... Lower limit switch, 32 ... Dynamic braking circuit, 33 ... Shutter braking second electromagnetic contactor.

Claims (1)

[Scope of utility model registration request] 1. A three-phase AC induction motor for winding up and raising a shutter curtain, wherein a DC power supply line is switchably connected between two AC power supply lines connected to the motor and another line. , When the electric motor is not driven in the shutter open state, it is linked to the switching from the AC power supply side to the DC power supply side, the motor is driven in reverse by the weight drop of the shutter curtain, and the motor is induced by the reverse driving. A self-weight lowering device for an electric shutter, characterized in that the descent speed of the shutter curtain is controlled by the generated power from the start of the self-weight descent to the landing.