JP7501469B2 - How to flip a metal plate - Google Patents

Description

The present invention relates to a technique for flipping heavy metal plates, such as steel plates. For example, the technique is suitable for flipping metal plates weighing 100 kg or more.

For example, when welding both sides of a thick steel plate for the purpose of repair, etc., it is necessary to turn the steel plate over. Also, when performing back-strip welding from one side of the steel plate, it is necessary to turn the steel plate over and inspect the weld bead formed on the other side of the steel plate.
In this way, there are cases where a turning operation is required to turn over the steel plate placed on the table, but it is difficult to turn over a heavy steel plate by hand.
Conventionally, as a simple method for inverting a steel plate, there is a method using a crane, as described in, for example, Patent Document 1.

Patent Document 1 describes a method in which a hanging piece is attached to one side of a steel plate and the end of the steel plate is lifted by a crane to turn the steel plate over.
Furthermore, as a method for inverting a steel plate without using a crane, there is also a method using a steel plate inverting device, as described in, for example, Patent Document 2 and Patent Document 3.

The reversing device described in Patent Document 2 is composed of two tables (a sending table and a receiving table) rotatably attached to each of two parallel rotating shafts. In Patent Document 2, after the steel plate is placed on the sending table, both tables are rotated vertically so that they face each other while tilted slightly toward the sending side from the vertical. In this state, the tables are rotated toward the receiving side from the vertical to transfer the steel plate from the sending table to the receiving table. After that, both tables are rotated in the opposite direction again to a horizontal position. Through this process, Patent Document 2 has a structure for reversing the steel plate.

The reversing device described in Patent Document 3 is equipped with a reversing frame that can rotate almost vertically for each steel plate placed on the frame, and a roller table that can move horizontally, and the device is used to reverse the steel plate. Patent Document 3 states that by using the device, it is possible to perform the reversing work of the steel plate without causing scratches on the surface of the steel plate.

Japanese Patent Application Laid-Open No. 53-65236 Japanese Patent Application Laid-Open No. 2-291339 JP 2013-123715 A

However, the methods described in Patent Documents 2 and 3 require a large-scale reversing device and a large work area dedicated to reversing. In other words, it is necessary to introduce large equipment, which is costly to introduce. In addition, since the place where the steel plate can be reversed is limited to the place where the equipment is installed, the steel plate needs to be moved to the place where the equipment is installed when reversing the steel plate, which is undesirable from the viewpoint of work efficiency.
On the other hand, in the steel plate reversal method using a crane as in Patent Document 1, if a crane is installed, the steel plate can be easily reversed. However, when the end of the steel plate is lifted and reversed as in Patent Document 1, the following problems arise.

Simply lifting the end of the steel plate makes it difficult for the steel plate to flip over, so after lifting the steel plate and raising it up, the crane must be moved laterally in the direction of the flip. In this type of crane operation, when the crane is raised and the steel plate is raised to a position where it can be moved laterally, if the crane operator is not skilled, there is a risk that the steel plate will break off the ground. If the steel plate breaks off the ground, the load will sway, and there is a risk that the load swaying will cause the steel plate to collide with nearby objects or people.

In addition, it is difficult to control the load of the steel plate on the ground when it is lifted. Therefore, there is a risk that the steel plate may slip on the ground or the platform when the crane moves sideways, and more crane skill than necessary is required to flip the steel plate without slipping.
The present invention focuses on the above-mentioned points, and aims to provide a technology that enables inversion work to be performed easily and safely by even an unskilled crane operator, using a crane already installed in a factory.

The inventors of the present invention have made the present invention as a result of extensive research into a method for easily turning over a metal plate by simply lifting up an end of the metal plate and lowering it.
In order to solve the problem, one aspect of the present invention is a plate inversion jig used to lift an end of a metal plate placed on a table with one side facing upward and invert the metal plate, the jig comprising a gripping portion that is detachably fixed to the end of the metal plate opposite the lifting side, and a protrusion that is formed integrally with the gripping portion and extends in a direction away from the opposite end, and the position of the tip of the protrusion, when attached to the metal plate, is eccentric to the other side of the metal plate in the thickness direction relative to the center position of the metal plate in the thickness direction.

Another aspect of the present invention is a method for flipping a metal plate placed on a table, which involves attaching a plate flipping jig described in one aspect of the present invention to an end of the metal plate, and lifting the end of the metal plate that is farther from the end to which the plate flipping jig is attached, so that the tip of the plate flipping jig is grounded on the ground, and the weight of the metal plate causes the metal plate to tilt toward the flipping side with the tip as a fulcrum.

When using a plate flipping jig according to an embodiment of the present invention, when the end of the metal plate is lifted and the metal plate is in a vertical position, the center of gravity of the metal plate is located on the side that will flip rather than the contact point of the tip of the jig.
Therefore, simply by lifting up the end of the metal plate, a moment in the direction of inversion is generated on the metal plate with the tip of the jig on the ground as a fulcrum before the metal plate assumes a vertical position. Therefore, simply by lifting up and lowering the metal plate, it is possible to invert the metal plate.

FIG. 2 is a side view showing a state in which a steel plate is placed on the table. FIG. 2 is a top view showing a state in which a steel plate is placed on a table. FIG. 2 is a diagram showing a plate inversion jig according to an embodiment of the present invention. 1 is a side view showing a state in which the center of gravity of a steel plate with its end portion lifted is aligned with a vertical line from the ground support point. FIG. FIG. 11 is another side view showing the state in which the center of gravity of the steel plate with its end portion lifted is aligned with the vertical line from the ground support point. FIG. 13 is a side view illustrating the eccentricity (offset) of the tip of the jig.

Next, an embodiment based on the present invention will be described.
In this embodiment, a steel plate is taken as an example of the metal plate, but the present invention is also applicable to metal plates other than steel plates.
In addition, in this embodiment, the metal plate will be described as having a plate shape having two opposing sides.
In this embodiment, a case where a steel plate placed on a table is turned over will be described as an example.
Before inversion, the top surface of the steel plate becomes one surface, and the bottom surface becomes the other surface.

1 and 2, the inversion operation will be described from a state in which two rod members serving as tables 5 are placed side by side on the floor and the steel plate 1 is placed on the tables 5. The rod members are made of long-axis members such as square timber or angle bar.
The steel plate 1 is suspended by a magnet, for example, and placed on a stand 5 .
In Figures 1 and 2, the hanging jig 2 and the plate reversing jig 4 are shown attached to the steel plate 1, but the hanging jig 2 and the plate reversing jig 4 can be attached to the steel plate 1 after the steel plate 1 is placed on the base 5.

(Plate inversion jig 4)
First, the configuration of the plate reversing jig 4 will be described.
The plate reversal jig 4 of this embodiment is a jig used to lift up an end of a steel plate 1 placed on a table 5 with one side facing upward, and reverse the steel plate 1.
As shown in Figs. 1 and 3, the plate inversion jig 4 includes a gripping portion 4A and a protruding portion 4B.

<Grip portion 4A>
The gripping portion 4A constitutes a gripping mechanism for fixing the end portion of the steel plate 1.
As shown in FIG. 3, the gripping portion 4A of the present embodiment includes an insertion portion 44 and a fastening structure (gripping mechanism).
The insertion portion 44 is formed in a substantially U-shape with one side open by a pair of opposing plate portions 41, 42 and a bottom plate portion 43 connecting one end sides of the pair of plate portions 41, 42. The pair of plate portions 41, 42 are disposed opposite each other with a gap wider than the thickness of the thickest plate among the steel plates 1 to be processed.

The fastening structure is composed of multiple sets of bolt holes 41a, 42a and bolts 46, 47. Specifically, one or more bolt holes 41a, 42a are formed in each of the plate portions 41, 42, and bolts 46, 47 are screwed into each of the bolt holes 41a, 42a, and the threaded tip of each bolt 46, 47 advances and retreats toward the space between the pair of plate portions 41, 42. The fastening structure may be provided on only one of the pair of plate portions 41, 42.
The gripping mechanism is not limited to a mechanism using bolts, and other known gripping mechanisms may be adopted. For example, the gripping mechanism may be a gripping mechanism using hydraulic pressure or the like, or a clamp mechanism in which one of a pair of opposing plate parts 41, 42 moves in the opposing direction. In other words, the gripping mechanism is not particularly limited as long as it can be fixed to the end of the steel plate 1.

<Protrusion 4B>
As shown in FIG. 1, the protrusion 4B is formed integrally with the grip portion 4A and extends in a direction away from the grip portion 4A.
The position of the tip 4Ba of the protrusion 4B, in a state where the gripping portion 4A is attached to the steel plate 1, is eccentric toward the back surface 1B (lower surface) of the steel plate 1 with respect to the center position in the thickness direction of the steel plate 1. Preferably, the position of the tip 4Ba of the protrusion 4B, in a state where it is attached to the steel plate 1, is eccentric toward the outside (lower) of the back surface 1B (lower surface) of the steel plate 1 in the thickness direction of the steel plate 1.

In the plate reversing jig 4 of this embodiment, the tip portion 4Ba is located outside one plate portion 42 of the pair of plate portions 41, 42, as shown in FIG.
In the present embodiment, the contour shape of the protruding portion 4B from the tip portion 4Ba toward the front surface 1A (upper surface) of the steel sheet 1 is formed in an arc shape. When the contour shape is an arc shape, the steel sheet can be smoothly inverted.
Here, it is preferable that the tip portion 4Ba is as eccentric outward as possible from the one plate portion 42 .

However, as shown in Fig. 6, when the plate inversion jig 4 is attached to the steel plate 1 placed on the stand 5, the tip 4Ba needs to be separated from the floor 6. Symbol H3 in Fig. 6 indicates the separation distance from the floor.
That is, as shown in FIG. 6, the eccentricity (offset amount) H1 [mm] of the tip portion 4Ba from one plate portion 42 must satisfy the condition defined by formula (1).
H1 + H2 < D1 ... (1)
here,
H2 [mm]: distance from the outer surface (lower surface) of the lower plate portion 42 to the lower surface 1B of the gripped steel plate 1 (see FIG. 6)
D1 [mm]: height of the platform 5.
Here, the contour shape of the protrusion 4B connecting the gripping portion 4A and the tip portion 4Ba is not limited to a straight line or a circular arc, and may be another contour shape. It is sufficient that the tip portion 4Ba has a shape that is eccentric in the thickness direction of the steel sheet 1.

(Action etc.)
In this embodiment, the steel sheet 1 that has been transported by magnetic attraction or the like is placed on a table 5 as shown in Figures 1 and 2. In this embodiment, the steel sheet 1 is placed on the right side of the table 5 in order to turn the steel sheet 1 leftward.
2, reference numeral 10 denotes a weld bead. The welding process for the steel plate 1 may be performed in a pre-process, or may be performed after the steel plate 1 is placed on the table 5.
2, a hanging jig 2 is attached to the right edge of the steel plate 1, and a plate reversing jig 4 having the above configuration is attached to the left edge of the steel plate 1. The hanging jig 2 and the plate reversing jig 4 are provided at two locations in the width direction for stability.
1, the plate reversing jig 4 is inserted into the steel plate 1 between the pair of plate parts 41, 42 constituting the insertion part 44 with the tip of the protruding part 4B facing the floor 6, and the end face of the steel plate 1 is brought into contact with the bottom plate part 43. Before insertion, the amount of screwing of the bolt 46 of the lower plate part 42 (the amount of protrusion from the inner surface of the plate part 42) is adjusted in accordance with the plate thickness.

Next, the bolts 47 that screw into the bolt holes 41 a of the upper plate portion 41 are tightened to fix the plate reversing jig 4 to the end portion of the steel plate 1 .
Next, a hook provided at the tip of a wire 30 (or chain) lowered by the overhead crane is hooked onto the hoisting jig 2. In Fig. 1, reference numeral 3 denotes a hoisting/rewinding device of the crane.
In addition, the position of the ceiling crane is preferably located to the left of the upper position of the tip portion 4Ba of the jig in a plan view.

Next, the right side (end) of the steel plate 1 is lifted up by winding up the wire 30 of the crane.
At this time, until the tip 4Ba of the jig touches the floor 6, the steel plate 1 is lifted while rotating around the corner 1Bb at the bottom of the left end face of the steel plate 1, which is in contact with the base 5, as a fulcrum.
When the tip 4Ba of the jig touches the floor 6, the steel plate 1 is lifted up while rotating with the tip 4Ba of the jig that has touched the ground as a fulcrum, and the steel plate rises up.

Furthermore, as shown in Figure 4, when the right side of the steel plate 1 is lifted up from a state in which the center of gravity Cg of the steel plate 1 is located on the vertical line VL passing through the tip 4Ba of the jig and is tilted to the right, a rotational moment M to the left is generated in the steel plate 1 due to its own weight.
That is, before the steel plate 1 rises vertically, that is, before the steel plate 1 is cut off from the ground, the steel plate 1 automatically tries to tilt to the inverted side (left side) due to its own weight.
When the crane operator confirms that the steel plate 1 has tilted to the inversion side, he stops winding the wire 30 by the crane and rewinds the wire 30, so that the subsequent inversion work is carried out by the weight of the steel plate 1 itself.

In this manner, in this embodiment, run-off caused by excessive hoisting (excessive lifting) can be prevented, and load swaying of the steel plate 1 caused by run-off can be avoided.
Furthermore, the operation of the crane is simple; the crane winds up the wire 30 to raise one side of the steel plate 1, and after the steel plate 1 has tilted to the reversing side, the reversing operation can be completed simply by lowering the wire 30, and the crane operation itself can be completed with simple operations.
Furthermore, the jig can be made simple in structure.

As described above, according to this embodiment, when the end of the steel plate 1 on the side opposite to the side where the plate reversing jig 4 is attached is lifted, if the steel plate 1 tilts toward the reversing side due to its own weight before the steel plate 1 is lifted to a position where it assumes a vertical posture, reversal of the steel plate 1 is completed by simply lowering the crane. Therefore, the steel plate 1 to be reversed does not run off the ground, so there is no risk of the load shaking, and furthermore, the steel plate 1 can be reversed by simply lifting and lowering the crane.
In addition, since the steel plate 1 can be turned over using a crane already installed in the factory, there is an advantage that the cost of introducing a large-scale turning device can be reduced and only a small manufacturing cost for the jig is required.

As described above, according to this embodiment, the steel sheet 1 can be turned over simply and safely without the need for an expensive turning device.
Here, Fig. 5 shows an example in which the eccentricity (offset) of the tip 4Ba of the jig is made smaller than in Fig. 4, and it can be seen that when the center of gravity Cg of the steel plate 1 is positioned on the vertical line VL passing through the tip 4Ba, the inclination of the steel plate 1 with respect to the vertical direction is smaller than in Fig. 4. Note that the inclination angles shown in Figs. 4 and 5 are examples.
In this way, in order to reliably prevent run-out, it is preferable that the offset amount H1 is large (see FIG. 6). However, if the above formula (1) is not satisfied, it becomes difficult to attach the jig to the steel plate 1.

(others)
The present disclosure may also have the following configuration.
(1) A plate inversion jig used to lift an end of a metal plate placed on a table with one side facing upward and invert the metal plate,
A gripping portion that is detachably fixed to an end portion of the metal plate opposite to the lifting side;
a protrusion formed integrally with the gripping portion and extending away from the opposite end;
Equipped with
a position of a tip end of the protrusion is eccentric to the other surface side of the metal plate with respect to a central position in a thickness direction of the metal plate when the protrusion is attached to the metal plate;
A plate inversion jig characterized by the above.

(2) When attached to the metal plate, the position of the tip of the protrusion is offset outward in the thickness direction of the metal plate from the other surface of the metal plate.
(3) A plate inversion jig used to lift an end of a metal plate placed on a table with one side facing upward and invert the metal plate,
a gripping portion having an insertion portion having a pair of plate portions opposed to each other with a gap wider than the thickness of the metal plate, the gripping portion being capable of gripping an end of the metal plate inserted between the pair of plate portions;
a protruding portion that is formed integrally with the insertion portion, protrudes toward the opposite side to the insertion side of the insertion portion, and has a tip portion that is positioned outside one of the pair of plate portions in the opposing direction of the pair of plate portions;
A plate inversion jig comprising:

(4) A method for inverting a metal plate placed on a table, comprising the steps of:
A plate reversal jig according to any one of claims 1 to 3 is attached to an end of the metal plate,
By lifting the end of the metal plate away from the end to which the plate inversion jig is attached, the tip of the plate inversion jig is grounded on the ground, and the weight of the metal plate causes the metal plate to tilt toward the inversion side with the tip as a fulcrum.

1 Steel plate 1A Surface (first surface)
1B Back side (other side)
1Bb Corner 2 Suspension jig 4 Plate inversion jig 4A Grip portion 4B Protrusion portion 4Ba Tip portion 5 Base 6 Floor 30 Wire 41, 42 Plate portion 41a, 42a Bolt hole 43 Bottom plate portion 44 Insertion portion 46, 47 Bolt Cg Center of gravity H1 Eccentricity (offset amount)
M Rotational moment VL Vertical line

Claims (3)

A method for inverting a metal plate placed on a table with one surface facing upward, comprising the steps of:
A plate inversion jig is used, the plate inversion jig comprising: a gripping portion that is detachably fixed to an end portion of the metal plate opposite to the lifting side; and a protruding portion that is formed integrally with the gripping portion and extends in a direction away from the end portion of the opposite side, the position of the tip of the protruding portion being eccentric to the other surface side of the metal plate with respect to the central position of the metal plate in the thickness direction in a state where the plate inversion jig is attached to the metal plate;
The plate inversion jig is attached to the end of the metal plate,
By lifting the end of the metal plate away from the end to which the plate inversion jig is attached, the tip of the plate inversion jig is grounded on the ground, and the metal plate is tilted to the inversion side with the tip as a fulcrum by the weight of the metal plate.
A method for inverting a metal plate, comprising: a position of a tip end of the protrusion is eccentric outwardly from the other surface of the metal plate in a thickness direction of the metal plate when the protrusion is attached to the metal plate;
2. The method for inverting a metal plate according to claim 1. A method for inverting a metal plate placed on a table with one surface facing upward, comprising the steps of:
a plate reversal tool including an insertion portion having a pair of plate portions opposed to each other with a gap wider than the thickness of the metal plate, a gripping portion capable of gripping an end of the metal plate inserted between the pair of plate portions, and a protrusion formed integrally with the insertion portion, protruding on the opposite side to the insertion side of the insertion portion, the protrusion having a tip portion positioned outside one of the pair of plate portions in the opposing direction of the pair of plate portions;
The plate inversion jig is attached to the end of the metal plate,
By lifting the end of the metal plate away from the end to which the plate inversion jig is attached, the tip of the plate inversion jig is grounded on the ground, and the metal plate is tilted to the inversion side with the tip as a fulcrum by the weight of the metal plate.
A method for inverting a metal plate, comprising:

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