JP3341055B2 - Electric hoist wire drum - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a wire drum of an electric hoist in which a hoisting wire rope is sequentially wound in a horizontal direction to lift a load.

[0002]

2. Description of the Related Art An example of a conventional electric hoist in which a hoisting wire rope is sequentially wound in a horizontal direction to lift a load will be described with reference to FIG. The drive mechanism of the electric hoist includes a hoisting motor 1 composed of a three-phase squirrel-cage induction motor, a speed reducer 2 for reducing the rotational force of the hoisting motor 1, and a rotational force reduced by the speed reducer 2. And a magnet brake 4 for braking the hoisting motor 1.

[0003] One end 5a of a hoisting wire rope 5 is fixed to the wire drum 3 by appropriate means, and the other end 5b is fixed to a drum case 7 via a hook block 6. Then, the load is hoisted and lowered by the rotational force from the drive mechanism.

[0004] In this case, in order to prevent a large force from being applied to one end 5a of the hoisting wire rope 5, even if the hook block 6 is lowered to a specified head, two or more turns are wound around the wire drum 3. With the upper wire rope 5 left, the wrapping effect generated by the frictional force between the wire drum 3 and the hoisting wire rope 5 secures the winding.

[0005] Such a conventional wire drum 3 is generally formed in a cylindrical shape, and a winding start portion (the left side of the wire drum in FIG. 4) of the winding wire rope 5 is also wound at a winding end portion (the wire in FIG. 4). The right side of the drum) also has a diameter D of the pitch circle of the wire drum 3 (see FIG. 5), that is, from the substantially axis to the substantially axis of the wire rope 5 when the winding wire rope 5 is wound around the wire drum 3. The diameter D of the wire drum 3 is the same.

On both sides of the wire drum 3, flange portions 3a, 3a are formed.
A thread-shaped groove 8 for guiding the winding of the hoisting wire rope 5 is cut in the circumferential surface of the hoisting wire rope 5, and the hoisting wire rope 5 is wound around the groove 8 in a single layer.

The shape of the thread-like groove 8 provided on the circumferential surface of the wire drum 3 will be described with reference to FIG.
Is slightly larger than the diameter d of the hoisting wire rope 5 so that the hoisting wire ropes 5 do not come into contact with each other, and the height c of the groove 8 is about 1/3 of the diameter d of the hoisting wire rope 5. The groove bottom radius R is formed to be slightly larger than the radius r of the winding wire rope 5.

The hoisting speed of the conventional electric hoist constructed as described above is usually a single speed if the rotational speed of the hoisting motor 1 is constant, since the shape of the wire drum 3 is cylindrical. .

In order to vary the hoisting speed of the electric hoist having such a configuration, a hoist motor 1 is provided with a pole number conversion type motor, and the number of poles is converted to change the speed.
It is known that the power supply frequency is made variable using an inverter, and the variable frequency is supplied to a hoisting motor to control the speed.

[0010]

In such a conventional single speed type electric hoist, since the hoisting speed is constant regardless of whether the load is applied or not, a waiting time is generated for the cargo handling worker. Therefore, there was a problem that work efficiency was poor. In addition, the variable-speed electric hoist has a problem in that the cost is increased because a pole number conversion type motor or an inverter is used for controlling the hoisting speed of the electric hoist.

The larger the frictional force between the wire drum and the hoisting wire rope in the helical portion of the hoisting wire rope fixed to the wire drum, the greater the force applied to the end of the hoisting wire rope. This is desirable for safety, and when hoisting a load using an electric hoist, a wire rope for slinging ( hanging on a wire rope for hoisting)
The ropes hanging on the hooks of the hook block are tensioned, so suspend the hoisting operation immediately before the suspended load leaves the floor, and when the ground is lifted (when the suspended load leaves the floor).
Although the hoisting operation is performed so as not to suddenly lift the suspended load by minimizing the impact of the cargo, the worker is often chased by the cargo handling operation to perform a rapid ground breaking operation. In such a case, a large force is applied to the wire rope for slinging, the wire rope for hoisting, and each part of the mechanical part due to the impact at the time of ground cutting, which is not preferable in terms of safety.
However, in the conventional electric hoist, there has been a problem in that no particular consideration is given to safety in terms of structure in this respect.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and the speed of hoisting can be easily changed according to actual cargo handling work, thereby reducing the waiting time of cargo handling workers and reducing the work efficiency. It is an object of the present invention to provide a wire drum of an electric hoist which can increase the safety and the safety.

[0013]

According to the first aspect of the present invention,
In an electric hoist in which a thread-shaped groove is provided on the peripheral surface of the wire drum, and a hoisting wire rope is sequentially wound in a horizontal direction in this groove to lift up a load, the diameter of the pitch circle of the groove of the wire drum is adjusted. At the winding start part of the winding wire rope, a large diameter part is formed, and at the winding end part of the winding wire rope, a small diameter part is formed,
The transition from the large diameter portion to the small diameter portion is formed in a tapered shape.

[0014] According to a second aspect of the present invention, the groove shape of the helically wound portion of the wire drum for winding the wire rope for winding is V-shaped.
It is characterized by having a shape.

According to a third aspect of the present invention, the thread-shaped groove provided on the peripheral surface of the wire drum on which the winding wire rope is wound is formed in a stepped shape, and the radius of the first-step groove is set to the radius of the winding wire rope. The same diameter as the radius or slightly larger than this,
The second step is characterized in that the groove bottom radius is formed slightly smaller than the radius of the winding wire rope.

[0016]

According to the first aspect of the present invention, at the time of winding,
During empty load operation until the sling wire rope is tensioned,
The wire rope for winding is wound around a large diameter portion of the wire drum and wound at a high speed. Then, after the winding wire rope is sequentially shifted to the tapered portion of the wire drum and wound up, during a steady operation after ground cutting, the winding wire rope is wound up at a small diameter portion of the wire drum and at a low speed. Roll up.

Further, during steady operation at the time of lowering,
The hoisting wire rope is rewound from the small diameter portion of the wire drum, and is rewound at a low speed. Then, after the winding wire rope is sequentially shifted to the tapered portion of the wire drum and rewound, during the empty load operation until the sling wire rope is relaxed, the winding wire rope is moved to the large diameter portion of the wire drum. Rewind at higher speed.

Further, according to the second aspect of the present invention, when a load acts on the hoisting wire rope at the wrapping portion of the hoisting wire rope fixed to the wire drum,
The hoisting wire rope further increases the frictional force between the wire drum and the hoisting wire rope due to the wedge effect caused by biting into the V groove of the wire drum.

Further, according to the third aspect of the present invention, the hoisting wire rope is wound into the first groove of the wire drum during the empty load operation, and the hoisting and lowering is performed during the load operation. The wire rope is wound into the second groove of the wire drum, and the wire is wound up and down.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of an electric hoist wire drum according to the present invention will be described below with reference to FIGS. The same members as those in FIGS. 4 and 5 are denoted by the same reference numerals and described. FIG. 1 is a vertical cross-sectional view of a wire drum according to the present invention, in which a part of the wire drum is cut away. FIG. FIG. FIG. 4 is also referred to in this embodiment.

In FIG. 1, reference numeral 9 denotes a casting-made wire drum on which a hoisting wire rope 5 is wound.
A drum body 9a is formed at the center portion, and flange portions 9b, 9b for preventing the hoisting wire rope 5 from falling off are formed on both sides thereof.

Reference numerals 9c and 9c denote support walls formed on the inner peripheral portion of the drum main body 9a, and bosses 9d and 9d for supporting the drum are formed at the front end thereof. The bosses 9d, 9d are rotatably supported by a bracket (not shown) of the hoisting motor 1 and a bracket (not shown) of the speed reducer 2 via bearings (not shown).

The drum body 9a of the wire drum 9 is shown in FIG.
As shown in, hoisting wire rope 5 of the wire drum 9
Winding start portion W1 (left side in FIG. 1) and wire
Winding end portion W3 of wire rope 5 for winding up drum 9
(Right side in FIG. 1).

This will be described in detail.
The diameter D1 of the pitch circle of the wire drum 9 in the winding start portion W1 is a large diameter portion, and the diameter D2 of the pitch circle of the wire drum 9 in the winding end portion W3 of the winding wire rope 5 is a small diameter portion. A transition portion W2 from the large diameter portion to the small diameter portion is formed in a tapered shape.

When the electric hoist is used as a hoist of a crane, the diameter D of the pitch circle of the wire drum 9 (see FIG. 5 showing a conventional one) and the hoist wound around the wire drum 9 The minimum value of the value D / d of the ratio to the diameter d of the wire rope 5 is specified in the crane structural standard. Therefore, in the wire drum 9 according to the present invention, the diameter of the pitch circle of the winding end portion of the hoisting wire rope 5.
D2 satisfies the specified value.

Next, the grooves in the wrapping portion W4 (the first two windings of the winding start portion W1) of the wire drum 9 for winding the winding wire rope 5 will be described with reference to FIG.

The shape of the groove is substantially V-shaped as shown in FIG. 2, and the winding wire rope 5 is wound around the V-shaped groove 10. For this reason, when a load acts on the hoisting wire rope 5, the hoisting wire rope 5 and the V wire 10 have a wedge effect due to the fact that the hoisting wire rope 5 bites into the V groove 10.
The frictional resistance between the groove 10 and the groove 10 increases, and the force applied to the end of the hoisting wire rope 5 is greatly reduced.

Next, the thread-shaped grooves formed on the peripheral surface of the drum body 9a of the wire drum 9 will be described with reference to FIG.
The shape of the groove 11 is formed in a step shape as shown in the figure,
There are two stages, a first stage groove 11a and a second stage groove 11b.
The radius R1 of the first groove 11a is the same as or slightly larger than the radius r of the wire rope 5 for winding, and the groove bottom radius R2 of the second groove 11b is It is formed slightly smaller than the radius r of the wire rope 5.

For this reason, when no load is applied to the hoisting wire rope 5, the hoisting wire rope 5 is wound into the first groove 11a of the wire drum 9, and A gap g is generated between the first groove 11b and the second-stage groove 11b.

When a load is applied to the hoisting wire rope 5, the hoisting wire rope 5 slightly changes into a gap g, and the second-stage groove 11 b of the wire drum 9 is formed.
It is wound up. At this time, the hoisting wire rope 5 enters the gap g, so that the impact at the time of ground separation is absorbed. That is, the impact at the time of ground cutting is absorbed by the amount of tightening of the winding wire rope 5 into the gap g of the wire drum 9.

On the other hand, the pitch p 'of the thread-like groove 11 is formed slightly larger than the diameter d of the wire rope 5 for winding, and the height c' of the groove 11 is larger than the diameter d of the wire rope 5 for winding. Is also slightly lower. The height c 'of the groove 11 at the transition portion W2 from the large-diameter portion to the small-diameter portion is set so that the winding start portion W1 and the winding start portion W1 except the winding portion W4 are removed to prevent the winding wire rope 5 from coming off. It is desirable to form it slightly higher than the winding end portion W3.

The operation of the electric hoist wire drum 9 will be described. At the time of winding the winding wire rope 5 around the wire drum 9, one end of the winding wire rope 5 is fixed to a starting end of a winding start portion W1 of the wire drum 9 which is a large-diameter portion by appropriate means. Roll
After being wound around the V-groove 10 (two turns) of W4, the hoisting wire rope 5 has a threaded groove 11 of a large diameter portion, a threaded groove 11 of a tapered transition portion W2, and a small diameter portion. The wire drum 9 is sequentially wound around the threaded groove 11 of the winding end portion W3.

Then, a hook block 6 is attached to the hanging part of the hoisting wire rope 5 as shown in FIG. 4, and the end of the hoisting wire rope 5 is fixed to the drum case 7. Accordingly, when the wire drum 9 is rotated by the driving force from the hoisting motor 1 of the hoisting drive mechanism (not shown), the hoisting wire rope 5 is sequentially wound in the direction of arrow X in FIG. Will be done.

In the hoisting operation, during the empty load operation until the sling wire rope is tensioned, the hoisting wire rope 5 is wound around the large diameter portion of the wire drum 9 and operated at a high speed. . That is, if the rotation speed of the rotating shaft of the hoisting motor 1 is constant, the large-diameter portion rotates faster, so that it is operated at a high speed. In this manner, the hoisting wire rope 5 is sequentially transferred to the tapered portion of the wire drum 9 and wound up, and during a steady operation after the ground cutting, the hoisting wire rope 5 is wound around the small diameter portion of the wire drum 9. It will be taken and run at low speed.

When a load acts on the hoisting wire rope 5 at the helical winding portion of the hoisting wire rope 5 fixed to the wire drum 9, the hoisting wire rope 5
Will bite into the V-groove 10 of the wire drum 9 so that the frictional force between the wire drum 9 and the hoisting wire rope 5 can be further increased, and a large force is not applied to one end 5a of the hoisting wire rope 5. Become like .

Further, at the time of empty load operation, the hoisting wire rope 5 is wound up by the first groove 11a of the wire drum 9 to perform hoisting and lowering. It is wound up in the second groove 11b of the drum 9 and is wound up and down.

[0037]

Since the present invention is configured as described above in detail, it has the following effects. According to the first aspect of the present invention, the hoisting speed is easily changed in accordance with the actual cargo handling operation, and the hoisting wire rope is operated at a high speed during empty loading until the wire rope is tensioned or relaxed, and the waiting time of the cargo handling worker is reduced. Therefore, the operation efficiency can be improved by reducing the load , and the load can be operated at a low speed at the time of load after the ground cut, so that the moving speed of the load can be slowed and the safety can be improved.

According to the second aspect of the present invention, the hoisting wire rope is fixed to the wire drum, and the hoisting wire rope bites into the V-groove of the wire drum in the wrapping portion of the hoisting wire rope. Since the frictional force of the wire rope for hoisting can be further improved, the force applied to the terminal portion of the wire rope for hoisting can be reduced, and safety can be improved.

According to the third aspect of the present invention, at the time of load operation, the hoisting wire rope is wound up in the second groove of the wire drum and wound up and down. Since the impact force can be absorbed, safety can be improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a wire drum according to an embodiment of the present invention, with a portion cut away.

FIG. 2 is a longitudinal sectional view showing in detail a groove of a shunt part of FIG. 1;

FIG. 3 is a longitudinal sectional view showing in detail a screw-shaped groove provided on a peripheral surface of the wire drum of FIG. 1;

FIG. 4 is a schematic view showing a mechanism of a conventional electric hoist.

FIG. 5 is a longitudinal sectional view showing a part of a threaded groove of a conventional wire drum.

[Explanation of symbols]

 5 Wire rope for hoisting 9 Wire drum 10 V groove 11 Thread groove 11a First groove 11b Second groove D1 Pitch circle diameter D2 Pitch circle diameter

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-54-72837 (JP, A) JP-A-1-317998 (JP, A) JP-A-2-233499 (JP, A) JP-A-51- 76753 (JP, A) Japanese Utility Model Showa 57-106693 (JP, U) Japanese Utility Model Application Hei 7-27019 (JP, U) Japanese Patent Publication No. 48-10682 (JP, B1) (58) Field surveyed (Int. ⁷ , DB name) B66D 1/30

Claims (3)

(57) [Claims] 1. An electric hoist in which a thread-shaped groove is provided on a peripheral surface of a wire drum, and a hoisting wire rope is sequentially wound in the groove in a lateral direction to lift a load.
The diameter of the pitch circle of the groove of the wire drum is formed at a large diameter portion at a winding start portion of the winding wire rope, and at a small diameter portion at a winding end portion of the winding wire rope. A wire drum for an electric hoist, wherein a transition portion from a large diameter portion to a small diameter portion is formed in a tapered shape. 2. A wire drum for an electric hoist according to claim 1, wherein a groove shape of a slot portion of the wire drum for winding the wire rope for winding is V-shaped. 3. A screw-shaped groove provided on a peripheral surface of a wire drum for winding a wire rope for winding up, wherein a step-shaped groove is formed, and a radius of the first-step groove is equal to or equal to a radius of the wire rope for winding up. 2. A wire drum for an electric hoist according to claim 1, wherein the wire drum is formed to be slightly larger than the groove, and the second step groove bottom radius is formed to be slightly smaller than the radius of the winding wire rope.