JP2577006Y2 - Hoist with emergency shut-off device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hoist, and more particularly, to a hoist provided with an emergency cutoff device also serving as an emergency limit switch.

[0002]

2. Description of the Related Art A hoist is a device that controls the rotation of a winding drum on which a wire rope is wound by a hoisting motor, raises a load suspended on a hook via the wire rope, and lowers or moves left and right to carry a suspended load. However, if the hook is raised too much because the wire rope is wound too much, a limit switch is provided to prevent the wire from being wound more than a predetermined amount.

In the case of a large capacity or explosion-proof hoist of 10 tons or more, an emergency circuit breaker also serving as an emergency limit switch is provided in the control box in consideration of the possibility that the limit switch may fail. It is built in, and in case of emergency, the emergency circuit breaker is shut off to ensure safety.

FIG. 4 is a side view of the hoist. Reference numeral 1 denotes an operating rod for operating the limit switch and the emergency breaker. One end of the hoist is rotatably supported by the rotary shaft 2 and the other free end is The hook 3 is provided above the hook 3.
Is rotated counterclockwise by the hook 3 when the control signal rises to a predetermined position, and the control circuit is turned off by a limit switch provided in the control box 4.

In the event that the limit switch fails and the hook 3 further rises, the emergency circuit breaker is operated to shut off the power.

In FIG. 4, reference numeral 5 denotes a drive unit which comprises a hoisting motor, a winding drum driven by the hoisting motor, an electromagnetic brake, and the like. 6 is a push button switch, 7 is a running wheel,
Reference numeral 8 denotes a rail, and 9 denotes a traversing motor, which has a built-in reduction gear and an electromagnetic brake, and drives the traveling wheels 7.

FIG. 5 shows a control circuit for hoisting and lowering in the control box 4 (omission for traversing is omitted), LS ₁ denotes the above-mentioned limit switch, and SE denotes an emergency breaker which also serves as a limit switch. If the LS ₁ operates normally, the circuit of the winding electromagnetic switch 12U is cut off and its contact 12U
₁ , 12U ₂ is released to stop the hoisting motive 10, and at the same time, the hoist is stopped by applying the brake.

[0008] Should When the limit switch LS ₁ is not cut failing control circuit is very breaker SE by upward movement of the operating rod 1 is cut forcibly.

In FIG. 5, reference numeral 16 denotes a push button switch, which corresponds to the push button switch 6 in FIG. The operating electromagnetic switch 12U Press raised push button 11U of the push button switch 16, its contacts 12U ₁ and 12U ₂ closes, solves the brake of the electromagnetic brake BM, is rotated hoist motor 10 in the winding direction at the same time You. When you release your finger from the push button 11U,
The electromagnetic switch 12U returns, and its contacts 12U ₁ , 12U ₂
Is released and the hoisting motor 10 stops.

The lowering is performed by the lower push button 11 of the push button switch 16.
Press D. When this 11D is pressed, the electromagnetic switch 12D operates, the contacts 12D ₁ and 12D ₂ close, the brake of the electromagnetic brake BM is released, and at the same time the hoisting motor 10D is released.
Is reversed in the lowering direction. Incidentally, it LS ₂ shows a limit switch hanging the load to operate if heavier than a predetermined value.

[0011]

[Problem to be solved by the invention] Limit switch LS
_{When 1} operates, the lower push button 11D of the push button switch 16
Pressing, down hook 3 rotates hoist motor 10 in the lowering direction 4, there is no problem because the limit switch LS ₁ is closed, when the emergency shut-off device SE is interrupted in operation, the push-button switch Even if the 16 push buttons 11D are pressed,
Since the power is off, it cannot be lowered and operation becomes impossible.

To remedy this, at a high position, the lifting brake is manually loosened, the hook 3 is lowered, and the operating rod 1 is lowered to recover the emergency circuit breaker SE or to mount the emergency circuit breaker SE. It is removed, the power is turned on, the winding is lowered, the operating rod 1 is lowered, and the emergency circuit breaker SE is attached again, or the recovery is performed by any method.

All of these operations are performed at a high place where the hoist control box is mounted, so that the operations are difficult.
In particular, when the hoist is manually released from the hoist, for example, when a load is suspended on the hoist, the load may slide down and be dangerous.

Further, it is more difficult to cut and remove the main distribution board in order to remove the emergency circuit breaker and recover the movable shaft (contact point) when working at a high place.

Therefore, the lid of the control box is removed and the emergency circuit breaker is manually turned on. However, if the atmosphere of the operating site of the hoist is strictly prohibited from fire, it is necessary to open the lid when the operation starts. Can not.

In any case, the cover of the control box is mounted with a large number of bolts. Particularly, in the case of a pressure-resistant explosion-proof hoist, it is tightly tightened with more bolts in order to maintain strength and airtightness. Therefore, removing and attaching the lid is very troublesome.

When the hoist is shipped, the emergency breaker is packed by raising the operating rod. Therefore, the emergency circuit breaker is transported in a state of being cut off, and the hook may swing and be cut off during the operation of the hoist. In some cases, the driver may unintentionally touch the operating rod to shut it off.
As described above, it is necessary to remove and put in the lid each time, and then put in the lid again after loading, which is very troublesome and has problems such as lowering the work efficiency.

Also, it cannot be known whether the emergency circuit breaker is currently open unless the cover of the control box is opened.
There were also problems such as.

In view of the above, it is an object of the present invention to provide a hoist provided with an emergency shutoff device that can be turned on without opening the control box cover when the emergency breaker breaks.

In addition, the open / close state of the emergency circuit breaker can be known from outside.

[0021]

In the present invention, a means for solving the above-mentioned problem is that a hoist having a built-in emergency circuit breaker for shutting off the power supply when the hoist is excessively wound in a control box of the hoist operates when the hoist is excessively hoisted. Operating rod, emergency shut-off operation means for shutting off the emergency circuit breaker in response to the operating rod, and manually turning on the emergency circuit breaker from outside the control box after the emergency circuit breaker shuts off. Emergency circuit breaker closing means. When the emergency circuit breaker is shut off, a power supply is directly connected to the hoisting motor and the electromagnetic brake by operating from the outside of the control box, and recovery means for turning the hoisting motor in the lowering direction is provided in the control box. .

Further, it is preferable to provide a display means for informing that the emergency breaker has been cut off by operating the limit switch when the emergency breaker has been cut off.

[0023]

When the emergency circuit breaker is closed and is to be recovered, the closing operation shaft protruding outside the control box is pushed up by the emergency circuit breaker closing means. This closes the emergency circuit breaker and restores control circuit power.

In the embodiment shown in FIG. 2, the operation unit of the recovery device provided outside the control box is manually rotated, and the switch in the control box is turned on. When the switch is turned on, the electromagnetic brake is released, and at the same time, the hoist motor is rotated in the lowering direction, the operating rod is lowered, and the emergency breaker is restored to the original position.

When the emergency circuit breaker is shut off, the limit switch is operated in conjunction with the interruption, and the display means informs that the emergency circuit breaker has been interrupted by lighting or a buzzer.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings. FIG. 1 is a schematic explanatory view of the inside of a control box according to one embodiment of the present invention, and a front view with a lid removed, and FIG. 2 is an explanatory view of another embodiment of the present invention.

In these figures, the same or corresponding parts as in FIGS. 4 and 5 are denoted by the same reference numerals, and description thereof is omitted.

FIG. 1 shows an embodiment in which the present invention is applied to a pressure-resistant explosion-proof type hoist. A large number of screw holes 11 for bolts are provided on the outer edge of the control box 4. Reference numeral 12 denotes a terminal block which relays between an external power supply and the push button switch 6 and an internal circuit. 13
Is an emergency operating shaft operated by the operating rod 1, and bearings 14,
14 ', one end protrudes from the lower part of the control box 4 and engages with the operating rod 1, and the other end has a funnel-shaped switch operating part 15
Are attached, and these form an emergency shut-off operation unit EO. Reference numeral 16 denotes a closing operation shaft for receiving the emergency circuit breaker SE, which is supported by bearings 17 and 17 '.
The lever 16 has a lever 18 at its tip and a spring receiver 19 at the other end.
0 is always biased upward in the figure. These form an emergency circuit breaker input section EF. 21 is a frame for the limit switch LS ₃ operated by vertical movement of the closing operation shaft 16 to open and close the limit switch LS _3. 22, 23
Is an operation arm of the emergency circuit breaker SE, and the operation arm 22 is provided on the switch operation unit 15 and disconnects one contact 22S from the other contact 23S when the operation rod 1 moves upward. The operating arm 23 is provided at the tip of the closing operation shaft 16 and closes the contact by pushing up the closing operation shaft 16 when the emergency circuit breaker SE is cut off and its contact is disconnected. Reference numeral 24 denotes a sign light. When the operation arm 22 moves upward, the operation arm 23 slightly follows the operation arm, the closing operation shaft 16 moves upward, and the contact of the limit switch LS ₃ is positioned on the inclined portion of the piece 21. Lights when it is done. Note that the indicating means using the indicating light may be a sounding sound such as a buzzer. Further, the limit switch LS ₃ may be provided at the upper end portion of the emergency operating shaft 13.

Next, the operation will be described. FIG. 1 shows a state in which the operating rod 1 is pushed upward by the hook 3 and the emergency circuit breaker SE is shut off.

In this state, the push button switch 1 shown in FIG.
Even if the down push button 11D of No. 6 is pressed, the hoisting motor 10 does not rotate because the emergency circuit breaker SE is cut off. Therefore, since the hook 3 cannot be lowered, the operating rod 1 cannot be moved.

Then, the lever 18 of the closing operation shaft 16 is pushed upward to close the emergency circuit breaker SE. When the emergency circuit breaker SE is turned on, the power is restored and the push button switch 1
6 by pressing the lower push button 11D, the hoisting motor 10
Rotates in the lowering direction to lower the hook 3. When the hook 3 descends, the operating rod 1 can also move downward, and can return to the original position. When the operating rod 1 is returned to the original position, the emergency circuit breaker SE is lowered together with the closing operation shaft 16 by the emergency operation shaft 13 in the closed state.

The limit switch LS ₃ is connected to the emergency circuit breaker S
When E is opened, the contact is closed when the closing operation shaft 16 moves upward by following the predetermined distance by the spring 20 to turn on the indicating lamp 14 to indicate that the emergency circuit breaker SE is cut off.

FIG. 2 shows another embodiment of the emergency cut-off device, in which the emergency breaker can be returned without operating the push button switch. Very breaker SE is, R, S, and two contact _{R-R 1, S-S} 1, T-T 1 for each T-phase, the two fixed contacts R bridging the contacts ', S', T ′ And a common emergency operating shaft 25 that can simultaneously move these fixed contacts. The emergency operating shaft 25 is engaged with the operating rod 1,
Moves upward, the movable contacts R ', S', T 'are disconnected from the fixed contacts. A recovery device 26 includes a switch 27 and an operation unit 28 for operating the switch 27 from outside the control box 4. The switch 27 closes a contact when the operation unit 28 is rotated and releases the hand. And the contacts are opened. Then, as shown in FIG. 3, when the contacts are closed, the hoisting motor 10 is directly connected to the power source, the hoisting motor 10 is rotated in the lowering direction, and at the same time, the electromagnetic brake BM is operated to operate the brake, as shown in FIG. I'm trying to solve it.

Therefore, when the emergency circuit breaker SE is opened, if the operation unit 28 of the recovery device 26 is manually rotated, the hoisting motor 10 rotates in the lowering direction, and the hook 3 is lowered. The operating lever 1 also returns to its original position. When the operating lever 1 returns to its original position, the emergency circuit breaker SE closes, the power is restored, and the original operable state is restored.

When the indicator light 24 is provided, the emergency operation shaft 2
5 top Install limit switches LS ₃ to the very operating shaft 25 so as to light an indication lamp 24 closes the contacts when moved upward. This indicator light may be a buzzer, as in the previous embodiment.

[0036]

[Effects of the Invention] As described above, in the present invention, when the emergency circuit breaker is activated, the emergency circuit breaker is turned on (recovered) by the emergency circuit breaker closing operation means from outside the control box without removing the cover of the control box. Dangerous work, such as the conventional method of loosening the brake manually and lowering the hook at a high position, or removing the cover of the control box, turning on the emergency circuit breaker, and then turning on again There is no need to perform any operation such as attaching the lid, and the operation is safe and the recovery operation is extremely simple. Therefore, the above-mentioned conventional problem is completely solved.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of the inside of a control box according to an embodiment of the present invention.

FIG. 2 is a schematic explanatory view of the inside of a control box according to another embodiment of the present invention.

FIG. 3 is a circuit diagram of one embodiment of the present invention.

FIG. 4 is a side view of the hoist.

FIG. 5 is a circuit diagram of a conventional hoist.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Operating rod 3 ... Hook 4 ... Control box 5 ... Drive part 6 ... Push button switch 10 ... Hoisting motor 11 ... Screw hole for lid mounting bolt 13 ... Emergency operating shaft 14, 14 '... Bearing 15 ... Switch operating part 16 ... Closing operation shaft 17, 17 '... Bearing 18 ... Lever 19 ... Spring support 20 ... Spring 21 ... Piece 22, 23 ... Operation arm 24 ... Indicator light 25 ... Emergency operation shaft 26 ... Recovery device 27 ... Switch 28 ... Operation section SE … Emergency breaker EO… Emergency break operation section EF… Emergency breaker closing section

Claims (3)

(57) [Scope of request for utility model registration] 1. A hoist having a built-in emergency circuit breaker for shutting off a power supply when the hoist is overwound in a control box of the hoist, an operating rod operated when the hoist is excessively hoisted, and shutting off the emergency circuit breaker in response to the operating rod. An emergency shut-off device, comprising: an emergency shut-off operation means; and an emergency breaker closing means for manually turning on the emergency breaker from outside the control box after the emergency breaker is shut off. Hoist. To 2. A control box of the hoist, in hoist with a built-in emergency shut-off device to cut off the power when excessive winding, and the operating rod which is actuated when excessive winding, in response to the operation rod
An emergency shutoff operating means for shutting off the emergency circuit breaker, and when the emergency circuit breaker is shut off, the power is directly connected to the hoisting motor and the electromagnetic brake by operating from outside the control box to lower the hoisting motor. A hoist provided with an emergency shutoff device, wherein recovery means for rotating in a direction is incorporated in the control box. 3. An emergency shutoff operation for operating the emergency circuit breaker.
The closing operation shaft which operates in response to the occurrence of interruption of the emergency operating shaft or very breaker means, re operating in response to these operating shaft
Mitt switch is provided, and the operation of the limit switch
Hoist with very cutoff apparatus according to claim 1 or 2, wherein the emergency shut-off device is provided with a display means for displaying that the blocked Ri.