KR102641587B1 - Drum-Type Hoist Over Winding Down Prevention System and Method - Google Patents

Abstract

The present invention relates to a system and method for preventing over-winding of a drum-type hoist. More specifically, in a drum-type hoist, the pressing time of the push button is measured during winding and unwinding of the hook, and when a certain lower limit is reached, an electric signal is stopped to prevent winding. It relates to systems and methods to prevent this from happening.
The method for preventing overwinding of a drum-type hoist according to an embodiment of the present invention is (A) to set the time when the hook is at the upper limit position to 0, to wind it in an uninterrupted continuous operation, and to measure the continuous operation time to reach the lower limit point. Setting the time until it reaches as the set time and storing it in the controller;
(B) the hoisting motor operates in a hoisting and unwinding operation, and the controller counts the hoisting and unwinding times of the hoisting motor;
(C) recognizing the position value of the hook in the controller as a set time and checking whether the unloading time of the hoisting motor reaches the set time; and
(D) preventing over-winding by stopping the unwinding operation of the hoisting motor when the set time is reached in the controller;
It is composed including.

Description

Drum-type hoist overwinding down prevention system and method {Drum-Type Hoist Over Winding Down Prevention System and Method}

The present invention relates to a system and method for preventing over-winding of a drum-type hoist. More specifically, in a drum-type hoist, the pressing time of the push button is measured during winding and unwinding of the hook, and when a certain lower limit is reached, an electric signal is stopped to prevent winding. It relates to systems and methods to prevent this from happening.

The hoist is designed to move a certain weight up and down as the user operates the control unit formed on the control panel.

These hoists are classified into various types depending on their structure, and as shown in FIG. 4A, drum-type hoists operate by winding and unwinding a wire rope on a drum having a certain diameter.

The drum-type hoist is an overwinding hoist that automatically cuts off the power and controls the operation when the wire rope, which is equipped with a hanging part (hook) that can hold heavy objects on the drum that winds the wire rope, is wound beyond a certain length. A prevention device is provided.

Conventional overwinding prevention devices measure the rotation speed of the drum and stop when a certain rotation speed is reached, or measure the rotation speed of the traction motor and stop it when a certain rotation speed is reached.

However, if the method of measuring and stopping the drum's rotation speed was not reflected in the hoist design stage, there was no way to supplement it further.

In addition, the method of stopping the lower limit operation by measuring the number of rotations of the hoisting motor was not adopted for general drum-type wire rope hoists because the cost was excessive because it used an encoder for measurement.

The wire rope hoists currently being distributed do not have a safety limit device for the lower limit operation for the same reason as above, so there is a problem in which a safety accident occurs where the end of the wire rope falls off due to excessive loosening and falls.

The red circle in Figure 1a represents the fixed end of the wire rope. When the wire rope is completely unwound, the fixed end of the wire rope is separated from the drum and the lead bar at the fixed end of the wire rope hits the worker's head, resulting in a safety accident.

In addition, if it does not fall off, there is a problem of accidents where the drum rotates in reverse due to the continuous downward motion and the wire rope is wound in the opposite direction around the drum, resulting in breakage of the wire rope.

That is, as shown in Figures 1b and 1c, if the drum rotates in reverse without the wire rope falling off and the wire rope is entangled in the drum and wound in the opposite direction, the wire may be broken due to breakage or the dismantling process will require a lot of time or manpower. It takes.

Publication number 10-2001-0105669 (publication date: November 29, 2001)

The present invention was made to solve the above-mentioned problems, and provides a system and method for preventing overwinding of a drum-type hoist that can prevent the hook from touching the floor when the wire rope is unwound from the rotating drum. The purpose.

In addition, another object of the present invention is to prevent the wire rope from being separated from the drum groove when the wire rope is excessively loosened, causing the wire rope to become entangled or being damaged by skipping the ledge of the drum groove and causing a safety accident, In addition, the aim is to provide a system and method for preventing overwinding of a drum-type hoist, which can prevent safety accidents that occur when the wire rope is twisted and wound in the opposite direction due to the reverse rotation of the drum as the winding continues.

An overwinding prevention system for a drum-type hoist according to an embodiment of the present invention for achieving the above-described object includes a hoisting motor that is connected to a three-phase power supply and operates to wind up and down a wire rope wound around the drum by forward and reverse rotation;

A push button that consists of an up button and a down button, and when the up button is pressed, the hoisting motor operates in an upward direction, and when the down button is pressed, the hoisting motor operates in a downward direction;

It consists of first and second contactors and first and second switches, where the first and second contactors are connected to the up and down buttons of the push button, and the first and second switches are connected between the three-phase power source and the hoisting motor. first and second contactor switches; and

It is connected between the down button and the second contactor, and the time when the hook is at the upper limit position is set to 0, and the continuous operation time is measured. The time until the lower limit point is reached is measured. A controller that stores the setting as a set time, then recognizes the position value of the hook as the set time, and controls the second contactor switch when the lowering operation time reaches the set time to automatically block the electrical signal of the hoisting motor;

It is composed including.

In addition, it is connected between the up button and the first contactor and is located at the upper limit point, but when the hook contacts the upper limit safety lever during the hoisting operation, the overwinding prevention device operates and blocks the first contactor switch. It prevents abnormal winding, and the controller detects the signal from the winding prevention device and resets it in the controller to correct the error.

The method for preventing overwinding of a drum-type hoist according to an embodiment of the present invention is (A) to set the time when the hook is at the upper limit position to 0, to wind it in an uninterrupted continuous operation, and to measure the continuous operation time to reach the lower limit point. Setting the time until it reaches as the set time and storing it in the controller;

(B) the hoisting motor operates in a hoisting and unwinding operation, and the controller counts the hoisting and unwinding times of the hoisting motor;

(C) checking whether the winding time of the hoisting motor reaches the set time in the controller; and

(D) preventing over-winding by stopping the unwinding operation of the hoisting motor when the set time is reached in the controller;

It is composed including.

In addition, (E) after step (D), the controller further performs a step of hoisting the hoisting motor for a certain period of time within a set time to return it to the upper lower limit.

In addition, the alarm sound is generated in step (D), and the alarm sound is canceled after step (E).

And (F) after step (B), if the hook contacts the winding prevention device at the upper limit during the hoisting operation and a detection signal is input to the controller, the controller further performs a step of resetting and correcting the error. It is characterized by

According to the means for solving the above-mentioned problem, it can be applied to an existing drum-type hoist at low cost, and it is possible to prevent the wire rope from being excessively unwound from the drum even after the load (heavy object) touches the floor.

In addition, it is possible to prevent safety accidents due to damage to the wire rope, which may occur when the wire rope becomes loose due to excessive loosening and is not wound properly in the drum groove.

In addition, it is possible to prevent accidents where the wire rope is excessively loosened and the end part falls away from the fixing groove.

In addition, safety accidents that occur when the wire rope is excessively loosened and the drum reverses can be prevented.

Figures 1A to 1C are photographs instead of drawings showing problems with conventional drum-type hoists.
Figures 2a and 2b are circuit diagrams showing an overwinding prevention system for a drum-type hoist according to an embodiment of the present invention.
Figure 3 is a flowchart showing a method for preventing overwinding of a drum-type hoist according to an embodiment of the present invention.
Figures 4a and 4b are pictures instead of drawings to explain the drum-type hoist.

Hereinafter, the configuration and operation of an embodiment of the present invention will be described with reference to the attached drawings.

It should be noted that the same components among the drawings are indicated with the same reference numbers and symbols as much as possible, even if they are shown in different drawings.

In describing the present invention below, if a detailed description of a related known function or configuration is judged to unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

Additionally, when a part "includes" a certain component, this means that it may further include other components, rather than excluding other components, unless specifically stated to the contrary.

Figures 2a and 2b are circuit diagrams showing an overwinding prevention system for a drum-type hoist according to an embodiment of the present invention.

As shown in Figures 2a and 2b, the overwinding prevention system of a drum-type hoist according to an embodiment of the present invention includes a hoisting motor (IM10), a brake (DB10), an overcurrent relay (EOCR100), and an overwinding prevention device (LS). -Ⅰ, LS-Ⅱ), overload prevention device (LOAD LIMITER), controller (100), push button (PSB), and contactor switch (M101, M102).

The hoisting motor (IM10) is connected to a three-phase power source and rotates forward and backward to raise and lower a wire rope wound around a drum with a certain diameter, thereby raising or lowering a heavy object hanging from a hook at the end of the wire rope.

The brake DB10 is, for example, a DC electromagnet (MAGNETIC) brake that uses direct current power obtained by rectifying three-phase power, and stops the hoisting motor IM10 at a desired position.

The overcurrent relay (EOCR100) is connected between the three-phase power supply and the hoisting motor (IM10) and protects the hoisting motor (IM10) by operating when the current exceeds the rated current value of the relay.

The winding prevention device (LS-Ⅰ, LS-Ⅱ) is connected to the up button (U) of the push button (PSB), which will be described later, and is connected between the three-phase power supply and the hoisting motor (IM10), and is located at the bottom of the drum box. For example, as shown in Figure 4b, when the hook exceeds the upper limit position due to overwinding and the hook contacts the upper limit safety lever (when contacting the overwinding prevention device), the power of the hoisting motor (IM10) is cut off. By stopping, damage to the drum box located at the top is prevented.

In particular, in the present invention, the overwinding prevention device may cause errors due to slipping of the brake (DB10) and frequent winding up and down operations, which may cause the hook to be higher or lower than the initially set position, so the upper limit winding and When the position of the prevention device is reached, the signal is received and reset to enable error correction.

Overload prevention device (LOAD LIMITER) Detects overload of a lifting machine, for example, electronically or mechanically, and prevents human and material disasters resulting from overload in advance.

The push button (PSB) consists of an up button (U) and a down button (D). When the up button (U) is pressed, the hoisting motor (IM10) rotates in the direction to raise the wire rope, and the down button (D) is rotated in the direction to raise the wire rope. When pressed, the hoisting motor (IM10) rotates in the direction of lowering the wire rope.

The contactor switches (M101, M102) are composed of a contactor and a switch. The switch is connected to the up button (U) and down button (D) of the push button (PSB), respectively, and the contactor is connected to the three-phase power supply of the main panel (MHB). It is connected between the hoisting motor (IM10).

At this time, when the contactor (M101) is connected in the order of R-phase, T-phase, and S-phase, the other contactor (M102) is connected in the order of S-phase, T-phase, and R-phase.

The switch maintains its normally off state, and when the up button (U) is pressed, the contactor (M101) operates and a constant voltage of the three-phase power supply is supplied to the hoisting motor (IM10), thereby rotating in the direction of raising the wire rope.

When the down button (D) is pressed, the contactor (M102) operates and the reverse voltage of the three-phase power supply is supplied to the hoisting motor (IM10), causing it to rotate in the direction of lowering the wire rope.

The controller 100 is connected between the down button (U) and the contactor of the contactor switch (M102) to measure the time during hoisting and lowering operations, and when the hoisting operation exceeds the set pressing time, the hoisting motor ( IM10) stops the lowering operation and generates an alarm sound.

In addition, the hoisting motor (IM10) is operated to lift for a certain period of time (for example, 2 seconds) within the set time to return to above the lower limit, and then the overwinding prevention is canceled and the alarm sound is canceled.

The pressing time of the controller 100 is set by pressing the down button (D) of the push button (PSB) with the hook positioned at the upper limit (Figure 4b) (start time 0 seconds) to turn on the hoisting motor (IM10). Measure the time until the hook is positioned at the lower limit by continuously uninterrupted lowering operation (for example, 60 seconds to reach the lower limit), set this as the pressing time, and store it in the controller 100.

That is, when the hook is located at the upper limit point, the setting time is set to 0 seconds, for example, and when the hook is located at the lower limit point, the setting time is set to 60 seconds, and the setting time is stored in the controller 100.

In this state, when the down button (D) is pressed while the hook is located at the upper limit, the unwinding operation occurs for 35 seconds and then stops, the hook is located at a point 35 seconds below the upper limit, and the controller 100 remembers this and starts the hoisting operation. , if expulsion occurs, time is measured at this point.

In other words, if the down button (D) is pressed for more than 25 seconds at the point below 35 seconds and the lowering action exceeds 25 seconds and exceeds the set time of 60 seconds (35 seconds + 25 seconds), the down button (D) is pressed continuously. Even if the contactor of the contactor switch (M102) does not operate under the control of the controller 100, the contact of the switch is released and the lowering operation of the hoisting motor (IM10) is stopped.

In addition, when the hoisting operation occurs for 25 seconds and stops by pressing the up button (U) starting from the point below 35 seconds, the hook is located at a point below 10 seconds (35 seconds - 10 seconds) from the upper limit, and the controller 100 remembers this and measures time at this point.

As a result, the up and down movements between the upper and lower limits can be repeated within the set time.

In addition, errors may occur due to slippage of the brake (DB10) and frequent winding up and lowering operations, which may cause the hook to be higher or lower than the initially set position, so use the upper limit winding prevention device (LS-Ⅰ, LS). -Ⅱ) When the position is reached, the controller can receive the signal and reset it to compensate for the error.

Figure 3 is a flowchart showing a method for preventing overwinding of a drum-type hoist according to an embodiment of the present invention.

As shown in FIG. 3, the method of preventing overwinding of a drum-type hoist according to an embodiment of the present invention first presses the up button (U) of the push button (PSB) to operate the hoisting motor (IM10) to lift the hook. It is located directly below (the upper limit point) where the winding prevention devices (LS-Ⅰ, LS-Ⅱ) are located at the bottom of the drum box (S302).

At this time, set the set time to 0 seconds and press the down button (D) of the push button (PSB) to continuously lower the hoisting motor (IM10) without interruption (S304).

As a result, the hook descends from the upper limit point where the overwinding prevention device (LS-I, LS-II) is located and reaches the lower limit point (S306).

Set the time at the upper limit to 0, measure the time (e.g. 60 seconds) (down button pressing time) until reaching the lower limit (S308), set this as the set time, and store it in the controller 100. (S310).

Accordingly, the controller 100 recognizes the set time as 0 seconds when the hook is at the upper limit point, and recognizes the set time as 60 seconds when the hook is at the lower limit point.

In other words, the position value of the hook is recognized as the set time.

In this way, with the set time stored in the controller 100, pressing the up button (U) or down button (D) causes the hoisting motor (IM10) to operate up and down, thereby raising and lowering the hoist (S312).

At this time, the controller 100 counts the winding up and unwinding time of the hoisting motor IM10 (S314).

While the controller 100 is counting the time, if the hook passes the upper limit and touches the overwinding prevention device (upper limit safety lever) and a detection signal is input from the overwinding prevention device (S316), it is reset (S318) and 302 It is saved as the set time set through step S308 (S310).

Meanwhile, while the controller 100 is counting the time in step 314, it is checked whether the lowering operation of the hoisting motor reaches (exceeds) the set time (for example, 60 seconds) in step S310 (S320) and the set time is reached (S320). If it exceeds, the controller 100 controls the contactor of the contactor switch (M102) so that the contactor does not operate and the contact of the switch is released to stop the lowering operation of the hoisting motor (IM10), resulting in overwinding. prevent (S322).

At this time, an alarm sound is generated to alert nearby workers (operators) and allow them to check.

After preventing the over-winding, in order to cancel the continuous alarm sound, press the up button (U) to activate the contactor (M101) and operate the winding operation for a certain period of time (e.g. 2 seconds) longer than the set time to automatically sound the alarm sound. is released and returns to the lower limit height (S324).

Next, the controller 100 disables overloading prevention and alarm sound (S326).

As seen above, the present invention sets the time to 0 when the hook reaches the upper limit (overwinding prevention device) position, then reels in an uninterrupted continuous operation, measures the operation time, and reaches the desired position (lower limit). After setting and saving the time, it operates normally if the hoisting and lowering motions are performed within the set time, but when the hoisting motion reaches the set time, the electrical signal is automatically blocked.

At this time, errors may occur due to the slipping of the brake and frequent winding up and lowering operations, which may cause the hook to be higher or lower than the initially set position. Therefore, when the upper limit point (overwinding prevention device) position is reached, the signal is received. Error correction can be performed by resetting.

Although the technical idea of the present invention has been described above along with the accompanying drawings, this is an exemplary description of a preferred embodiment of the present invention and does not limit the present invention.

In addition, it is clear that anyone skilled in the art can make various modifications and imitations without departing from the scope of the technical idea of the present invention.

100: Controller DB10: Brake,
IM10: Hoisting motor
EOCR100: Overcurrent relay IM10: Hoisting motor
LOAD LIMITER: Overload prevention device LS-Ⅰ,LS-Ⅱ: Overload prevention device
M101,M102: Contactor switch PSB: Pushbutton

Claims (6)

A hoisting motor that is connected to a three-phase power source and rotates forward and backward to raise and lower the wire rope wound around the drum;
A push button that consists of an up button and a down button, and when the up button is pressed, the hoisting motor operates in an upward direction, and when the down button is pressed, the hoisting motor operates in a downward direction;
It consists of first and second contactors and first and second switches, where the first and second contactors are connected to the up and down buttons of the push button, and the first and second switches are connected between the three-phase power source and the hoisting motor. first and second contactor switches; and
It is connected between the down button and the second contactor, and the time when the hook is at the upper limit position is set to 0, and the continuous operation time is measured. The time until the lower limit point is reached is measured. After saving the setting as a set time, when the hoist motor operates and continuously lowers the hook while the hook is at the upper limit point, the set time, which is the time when the hook reaches the lower limit point, is recognized and the lowering operation is performed. A controller that automatically blocks the electrical signal of the hoisting motor by controlling the second contactor switch when the time reaches the set time;
Overwinding prevention system for drum-type hoist including. According to paragraph 1,
It is connected between the up button and the first contactor and is located at the upper limit point. When the hook touches the upper limit safety lever during the hoisting operation, the overwinding prevention device operates and blocks the first contactor switch, preventing further hoisting. An overwinding prevention system for a drum-type hoist, characterized in that the controller detects a signal from the overwinding prevention device and resets the controller to correct the error. (A) Set the time when the hook is at the upper limit position to 0, recommend continuous operation without interruption, measure the continuous operation time, set the time until it reaches the lower limit as the set time, and save it in the controller. step;
(B) the hoisting motor performs a hoisting and unwinding operation, and the controller counts the hoisting motor hoisting and unwinding times;
(C) When the hoist motor operates with the hook at the upper limit point and continuously lowers the hook, the hoisting motor's unwinding time in the controller is set at the set time, which is the time when the hook reaches the lower limit point. Checking whether it has been reached; and
(D) preventing over-winding by stopping the unwinding operation of the hoisting motor when the set time is reached in the controller;
Method for preventing overwinding of a drum-type hoist including. According to paragraph 3,
(E) A method of preventing overwinding of a drum-type hoist, characterized in that after step (D), the controller further performs a step of winding up the hoisting motor for a certain period of time within a set time to return it to the upper lower limit point. According to paragraph 4,
A method of preventing overwinding of a drum-type hoist, characterized in that the alarm sound is generated in step (D) and the alarm sound is canceled after step (E). According to paragraph 3,
(F) If the hook contacts the overwinding prevention device at the upper limit during the hoisting operation after step (B) and a detection signal is input to the controller, the controller further performs a step of resetting and correcting the error. A method of preventing overwinding of a drum-type hoist.

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