JPS59227686A - Ingot tongue - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention is a method for vertically suspending ingots such as round, square, and flat slabs.
This invention relates to the improvement of ingot tongs for use in tasks such as horizontal hanging, vertical hanging, and horizontal lifting.

In general, ingot tongs, which are used as a device for lifting and transporting ingots, are equipped with a pair of hanging arms from the tong body that grip the target ingot. With the tongs in the ingot position, the winter melon is pressed against the ingot by moving the pair of arms in the approaching direction using the drive motor, and then when the tongs are pulled upward, the weight of the ingot is transferred to the winter melon pressed against the ingot. is provided so that these claws are pulled down relative to the arm by the action of
Moreover, when these claws are pulled downwards against the arm,
By being guided and supported by the arms so as to narrow the distance between the pair of opposing claws, a stronger gripping force can be obtained.

The gripping force of the pair of claws on the ingot originates from the weight of the ingot, and it is necessary to obtain a strong gripping force by moving the claws downward relative to the arms. Usually, a biasing spring force is applied to the arm to bias it to a predetermined upper limit initial position.

By the way, the ingot tongs having such a configuration sometimes causes the following problems during use. That is, considering the operation of lowering a predetermined ingot etc. from a suspended state onto a loading place, for example, a roller table, this involves lowering the tongs to fully place the ingot etc. on the table. After this, the driving motor moves the pair of hanging arms to release the gripping state of the ingot by the pair of claws, but if the descent of the tongs at this time is flat, the load on the ingot will be reduced. The part remains acting on the claw of the hanging arm, and in this state, forcing the drive motor to expand the hanging arm may cause damage to the mechanism. As the clamping suspension is momentarily released upon opening, there is a risk that an impactful load will be applied to equipment such as the roller table below.

On the other hand, if the tongs are lowered more than necessary, the hanging arm of the tongs will continue to grip the ingot with its claws, since tongs are generally used by suspending them from crane hooks. The gripping force from the drive motor remains) and the crane stands on its own, but the crane's flange has descended too much, causing the hanging part to loosen, and when the hanging arm is subsequently expanded. There is also the problem that the tongs may fall instantaneously by the amount of slack, collide with equipment such as a roller table below, and damage each other.

These problems are particularly problematic when the operation of lifting and lowering the tongs generally relies on the operator's feeling.

Therefore, it is desirable to provide a means for electrically or mechanically detecting whether the tongs have been lifted to a sufficient degree.For example, a load detection means using a load cell may be provided on the crane side to It is detected that the lowering has been completed, or the claw, which is provided to move downward relative to the hanging arm as described above, returns to the initial position f by lowering the tongs. Some methods have been proposed, such as providing a means to detect this.

By these means, problems such as falling of the ingot, falling of the tongs, etc. can be effectively prevented.

However, according to studies conducted by the present inventors, it has been found that even with the above-described detection method, unreasonable force may be applied to the drive motor when the hanging arms are expanded after being suspended. Considering the cause, the above method is basically to confirm that the claws of the tongs have returned to the position at the beginning of lifting with respect to the hanging arm, and to check the gripping force of the claws on the ingot that has settled. This is understood to be because it has not yet been completely released in this state.

In view of the above points, the inventors of the present invention have proposed to provide ingot tongs in which the gripping force of the claws can be released by lowering the tongs a little further after the ingot has settled and died when the tongs are suspended. The present invention has been achieved in view of objective (5).

Accordingly, the gist of the present invention to achieve such an object is to provide a method for each of the opposing inner sides of a pair of hanging arms that are provided on a beam so that the opposing distance between them can be contracted, closed, and expanded. , a claw holder including claws for grasping the ingot is assembled, and these claw boulders are moved diagonally inward and downward from the initial resting position when the hanging arms rise due to the weight of the ingot held by the claws. In the ingot tongs configured to be movably guided to approach each other and increase the gripping force, each of the pair of claw holders is moved diagonally outward and slightly upward from the initial rest position opposite to the downward movement direction. The ingot tongs are provided movably relative to the hanging arm within a range up to an upper limit position of the ingot tongs.

As a structure for making such a claw holder freely movable outward and upward from an initial resting position, for example, a compressed biasing spring is built into the claw holder, and the lower end of this biasing spring is attached to a part of the hanging arm. (6) Although it can be configured so that they are separably engaged, it is not particularly limited to this configuration.

The present invention will be described below based on embodiments shown in the drawings.

In FIG. 1, 1 is an ingot to be lifted, 2 is a hanging ring suspended from a crane hook (not shown),
It is fixed so as to be located at the center of the beams 3, 3'. 4
, 4' are supported by a drive motor (not shown), and hanging arms are mounted on the top of 3' so that they can be moved to close and close, and to expand and separate in the left and right directions in the figure. The lower end portion hanging down is provided with temporary claws for holding the ingot 1, and a guide/support mechanism for the claw holder.

An example of a mechanism for retracting, closing, and expanding these hanging arms 4, 4' is a drive screw 5, 5' that is driven and rotated via a motor, torque limiter, snow rocket, chain (none of which is shown), etc. Then, the female threaded block 6.6' is assembled to the arm 4.4' and engaged and screwed together, and by the rotation of the drive screws 5, 5', the female threaded block 6.6' is attached to the hanging arm 4, 4.
′ is contracted and closed on beam 3.3′.

One example is one that is configured to expand and slide. It should be noted that symbols 5' and 6' in the above description are symmetrical with those of symbols 5 and 6, and therefore illustration thereof is omitted.

Next, the claw guide/support mechanism, which is a characteristic part of the present invention, will be described.Since this has the same structure for each of the claws assembled to the opposing pair of arms 4#4', the second In the subsequent figures, only one side is shown.

FIG. 2 shows the case where the tongs are lowered and are in a ready position where the claws 7 grip the input. This pawl 7 is fixed at the lower end of the pawl holder 8 on the opposing surfaces of a pair of pawl holders. The ingot is biased to the initial rest position by force, and when lifting the ingot, it is moved diagonally downward (as shown by arrow C in the figure) at an angle θ with respect to the vertical direction.
It is assembled so that it can be moved diagonally inwardly and downwardly between a pair of opposing arms. That is, the empty space 8a of the claw holder 8
The built-in bias spring is supported by a bolt-shaped spring guide 11 whose upper end is flat (12) and a claw holder 8, and a spring guide support 10 assembled to the lower end of the spring guide support 10. and the empty space 8a of the claw holder 8
The claw holder is mounted in a compressed state between the upper end walls 8b.
The support shaft 13 from the hanging arm 4 inserted into the empty space 8a of 8
The spring guide support 10 is provided so as to engage with the claw holder 8 and apply an upward spring force to the claw holder 8.

The claw holder 8 is provided so that it can be moved downwardly in the C direction by a guide (not shown) against the spring force of the biasing spring 9, and when the ingot 1 is grasped, the claw is moved by the reaction force. Since a counterclockwise rotational moment in FIG. 2 acts on the holder 8, in order to stop the rotation due to this moment, the upper inner surface 8C and the lower outer surface 8d of the claw holder 8 are A pair of rollers 14 and 15 that engage are arranged and are rotatably supported by the hanging arm 4.

Engagement surfaces 8c and 8 with rollers 14 and 15 on the claw holder 8 side
Since d also serves as a surface that determines the downward movement direction of the claw holder 8, it forms an inclined surface that coincides with the direction of arrow C described above. The feature of this embodiment is that, in addition to the mounting structure of the biasing spring 9, a through hole 16 for fitting the support shaft 13 into the cavity 8a of the pawl holder 8 is provided to prevent movement of the pawl holder 8. It has an elongated shape with respect to the direction (direction C in the figure), and is provided so as to have an excessive distance between it and the through hole 16 below the support shaft 13 in the normal resting state shown in the figure.

Due to the claw holder 8 and its guide/support mechanism constructed as described above, the hanging arms 4 on both sides are now in the state shown in FIG.
4' is contracted and closed by a drive motor (not shown) to press the claw 7 onto the ingot 1 as shown in FIG. 8, a downward force is applied due to the weight of the slurry f1. Therefore, the claw holder 8 is moved downwardly and inwardly against the upward biasing spring force, and since this downward movement direction is the direction of arrow C in FIG. 2 as described above, the claw 7 The clamping force on the ingot 1 increases as the claw holder 8 - moves downward, and the downward movement of the claw holder 8 stops at a position where the weight of the slab 1 is balanced. The ingot is then ground cut. (See FIG. 4) At this time, the clamping reaction force acting on the pawl holder 8 is supported by the rollers 14 and 15. In the figure, 17 is a striker 1 for activating a limit switch 18, and 18 is a limit switch that determines the limit of downward movement of the claw holder 80. When this switch is activated, the gripping force of the ingot 1 is appropriate. This is a guideline for correcting the clamping operation.

Furthermore, 19 is a second limit switch, which sets the upward movement limit when the claw holder 8 moves upward from the initial resting position (the position shown in FIG. 2) by engagement with the striker 17. This shows that. They are responsible for this effect.

Next, to explain the case where the tongs are lowered and the ingot 1 is loaded and suspended on a predetermined equipment such as a roller table, the suspended ingot 1 is placed on the floor.
The claw holder 8 moves upward in the return direction from the downwardly moved position shown in FIG. 4, and when it returns to the position shown in FIG.
The action of pushing down the claw holder 8 due to the weight of is released.

However, when the hanging arm 4 is expanded from the state shown in FIG. As already mentioned, excessive force may be generated on the drive motor due to the strain at the part 6.

Therefore, in this embodiment, the lowering of the tongs is not stopped at the position shown in FIG. 3, but is continued further, so that the gripping force can be released. That is, according to the above-described structure of this embodiment, when the tongs are lowered from the position shown in FIG. Therefore, the claw holder 8 is relatively moved upward to the upper side of the hanging arm 4, and this upward movement is in the opposite direction to the direction C in Fig. 2. Since it is located outwardly and upwardly between the pair of hanging arms, it expands outwardly along with the upward movement and disengages from the ingot 1.

The upward movement of the claw holder 8 only needs to cause the claw and ingot to come loose to a slight degree; on the other hand, if this upward movement is performed more than necessary, the engagement between the crane hook and the tongs' hanging portion may loosen. As already mentioned, in this embodiment, the limit of upward movement of the claw holder 8 can be detected by turning on the second limit switch 190. The operator may be informed of this by turning on the second limit switch 19, or the tongs may be stopped from descending. Fifth
The figure shows the state in which the claw holder 8 has moved upward from the initial rest position relative to the hanging arm 4, and the spring guide support 10 of the biasing spring 9 is spaced apart from the support shaft 13. It's stuck to what's floating.

If the hanging arms 4 are expanded in this state, the gripping force of the claws 7 on the ingot 1 is completely released, so the advantage is that no unreasonable force is generated on the drive motor, etc. .

As described above, according to the present invention, in the tongs configured to grip the ingot by the claws (13), the claws can be moved upward from the resting position before lifting the ingot. Although it is simple, it has the advantage of effectively releasing the gripping force when suspending the tongs, and its practical benefits are extremely large.

Note that the present invention is not limited to the above-mentioned embodiments, and is not limited to, for example, supporting the reaction force of the ingot gripping force by a pair of rollers. It goes without saying that the means used to do this may also have other configurations.

[Brief explanation of the drawing]

Figure 1 of the drawings is a front view including a partial cross section showing the general structure of the tongs to which the present invention is applied, and Figures 2 to 5 are schematic diagrams of the structure of part of the hanging arm portion of the tongs and the positional displacement of the claw holder. FIG. 1: Ingot 2: Hanging ring 3, 3': Beam 4, 4': Hanging arm 5
: Drive screw 6: Female thread (14) 7: Claw 8: Claw holder 8a: Blank space
8b: Upper inner wall 8c, 8d: Engagement surface
9: Biased spring 10: Spring guide 11: Spring guide support 12: Nut 13: Support shaft 14
, 15: Roller 16: Through hole 17: Striker 18, 19: Limit switch Fig. 1 (15) Fig. 2 Fig. 5

Claims (2)

[Claims] (1) A claw holder including a claw for grasping an ingot is attached to each of the opposing inner sides of a pair of hanging arms that are provided on the beam so that the space between them can be contracted, closed, and expanded. These claw holders are configured so that when the hanging arm rises, the claw holders are guided to move diagonally inward and downward from the initial rest position and approach each other to increase the gripping force. In the input tongs, each of the pair of pawl holders is provided to be movable relative to the hanging arm within a range from the initial rest position to an upper limit position diagonally outward and slightly above the direction opposite to the downward movement direction. Ingot tongs characterized by: (2) The ingot tong according to claim (1), wherein the upper limit position of the upward movement of the claw holder is determined as a set position of a limit switch.