Steel bar gripping device, steel bar gripping method, and steel bar conveying method

Abstract

To provide a steel bar gripping device, a steel bar gripping method, and a steel bar conveying method that are able to stably grip steel bars of a plurality of sizes of different diameters according to each size even when a gripping position of a steel bar is deviated from an expected position regardless of whether the steel bar is a high-temperature steel bar or a low-temperature steel bar.SOLUTION: A steel bar gripping device 3 can grip steel bars S of a plurality of sizes of different diameters and a circular cross-section according to each size. The steel bar gripping device 3 includes a claw member 6a on one side and a claw member 6b on the other side, made of metal and configured to grip a steel bar S of a size to be gripped among the steel bars S of the plurality of sizes. Each claw member 6a, 6b has a recess 7 having a curvature radius R1 larger than a radius of a steel bar S having the largest diameter among the steel bars S of the plurality of sizes, and a plurality of projections 81 to 89 are formed in the recess 7. A shape and an arrangement of the plurality of projections 81 to 89 in each of the claw members 6a, 6b are set so as to come into contact with all of the steel bars S of the plurality of sizes at two or more points.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a bar steel gripping device, a bar steel gripping method, and a bar steel conveying method.

Background Art

[0002] Samples are generally taken from the bar steel manufactured in a bar and wire factory for material tests and the like. Then, the collected samples are marked by a marking device or by handwriting by an operator, and thereafter, the marked samples are put into sample storage bags and conveyed to a material test site.

[0003] Here, when conveying the collected samples to a marking device or a handwriting work area, or conveying the marked samples to sample storage bags, it is desired to automatically convey the samples by a robot device. Conventionally, as a gripping mechanism attached to a robot device for gripping bar steel or a workpiece having a curved surface shape, for example, those shown in Patent Document 1 and Patent Document 2 have been proposed.

[0004] The adsorption gripping mechanism shown in Patent Document 1 is such that when the main adsorption pad is adsorbed to the workpiece, the tilting member tilts together with the sub-rod as the main rod moves, and the sub-adsorption pad provided on the sub-rod moves in the axial direction of the main rod while changing the angle with respect to the adsorption surface of the main adsorption pad to adsorb the workpiece. According to the adsorption gripping mechanism shown in Patent Document 1, a workpiece having a curved surface with inconsistent shape and size can be stably and surely gripped.

[0005] Further, the adsorption hand shown in Patent Document 2 has a side view formed by a conical frustum-shaped hammer surface with an open upper bottom and an open lower bottom, an adsorption port formed by the open upper bottom, and an external adsorption port formed by the open lower bottom. It is provided with an adsorption part in which a slit is formed from the external adsorption port on the side part, and an auxiliary adsorption part that covers the slit of the adsorption part from the outside in the radial direction of the adsorption part and adheres to the adsorption part when the inside of the adsorption part is depressurized. According to the adsorption hand shown in Patent Document 2, it is possible to grip a gripping object whose adsorption surface is a curved surface and a gripping object having irregularities on the adsorption surface.

Prior Art Document

Patent Document

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in the case of the adsorption gripping mechanism shown in the conventional Patent Document 1, the main adsorption pad and the auxiliary adsorption pad are used, and in the case of the adsorption hand shown in Patent Document 2, the adsorption part and the auxiliary adsorption part are used. These main adsorption pads and the like are members having elasticity and are generally made of a rubber-based or resin-based material. For this reason, these main adsorption pads and the like can be applied to workpieces at normal temperature, but cannot be applied to workpieces at high temperature from the viewpoint of heat resistance. In a bar factory, samples taken from steel bars for material tests and the like have a high temperature of about normal temperature to 700 ° C, and cannot be rapidly cooled in order to prevent tissue changes and cracks. Therefore, when handling the sample, it is necessary to handle it in a high temperature state of about normal temperature to 700 ° C, and it is not possible to apply a gripping mechanism using a main adsorption pad or the like attached to a robot device.

[0008] In general, for the gripping and handling of a workpiece by a gripping mechanism attached to a robot device, the workpiece is recognized as a gripping target by a camera or a sensor, the coordinates of the recognized object are grasped, and the gripping mechanism attached to the robot device is operated to the gripping position of the workpiece. However, the recognition of the workpiece by the camera or the sensor does not necessarily detect the exact position of the workpiece, and there are cases where the gripping mechanism grips the workpiece at a position deviated from the position where it can stably grip the workpiece.

[0009] Furthermore, in a bar steel factory, rolling is carried out not only on bar steels of a certain diameter but also on bar steels of a plurality of different diameters. If the shape of the gripping device is changed every time the size of the bar steel is changed, there will be demerits such as a decrease in productivity and an increase in costs due to a decrease in the rolling operation rate, and an increase in spare parts for maintaining the shapes of a plurality of gripping devices.

[0010] Therefore, the present invention has been made to solve these conventional problems, and an object thereof is to provide a bar steel gripping device, a bar steel gripping method, and a bar steel conveying method that can stably grip each size even when the gripping position of the bar steel deviates from the assumed position, regardless of whether the bar steel is hot or cold, for bar steels of a plurality of different diameters.

Means for Solving the Problems

[0011] In order to solve the above problems, a bar steel gripping device according to an aspect of the present invention is a bar steel gripping device capable of gripping bar steels of a plurality of different sizes having a circular cross section for each size, and is attached to each of an arm on one side and an arm on the other side that move toward and away from each other in a separable manner. When the arm on one side and the arm on the other side move in a direction approaching each other, a metal claw member on one side and a claw member on the other side for gripping a bar steel of a size to be gripped among the plurality of sizes of bar steels are provided. Each of the claw member on one side and the claw member on the other side has a depression having a radius of curvature larger than the radius of the bar steel having the largest diameter among the plurality of sizes of bar steels, and a plurality of protrusions are formed in the depression. The shape and arrangement of the plurality of protrusions in each of the claw member on one side and the claw member on the other side are such that when gripping the bar steel with the claw member on one side and the claw member on the other side, contact is made with all of the plurality of sizes of bar steels at two or more contact points.

[0012] Further, a bar steel gripping method according to another aspect of the present invention is to grip a bar steel of a size to be gripped among bar steels of a plurality of different sizes having a circular cross section using the above-described bar steel gripping device. Further, a bar steel conveying method according to another aspect of the present invention is to grip a bar steel of a size to be gripped among bar steels of a plurality of different sizes having a circular cross section using the above-described bar steel gripping device, and convey the bar steel gripped by the bar steel gripping device by a robot device.

Advantages of the Invention

[0013] According to the bar steel gripping device, bar steel gripping method, and bar steel conveying method according to the present invention, for bar steels of a plurality of different sizes, regardless of whether they are hot bar steels or cold bar steels, even when the gripping position of the bar steel deviates from the assumed position, it is possible to stably grip each size.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments shown below illustrate devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention does not specify the materials, shapes, structures, arrangements, etc. of the components in the following embodiments. Also, the drawings are schematic. Therefore, it should be noted that the relationship between the thickness and the planar dimensions, ratios, etc. are different from the actual ones, and there are also portions where the dimensional relationships and ratios between the drawings are different.

[0016] FIG. 1 shows a robot device equipped with a steel bar gripping device according to an embodiment of the present invention. The robot device 1 shown in FIG. 1 is a vertical articulated robot of a six-axis mechanism that constitutes a steel bar conveying device for conveying a plurality of sizes of steel bars S having circular cross-sections and different diameters for each size. This robot device 1 includes a robot arm 2 and a steel bar gripping device 3 attached to the tip of the robot arm 2.

[0017] The robot device 1 conveys, for example, a sample of the steel bar S taken from a hot-rolled steel bar to a marking device (not shown) for material testing or the like, or conveys the sample marked by the marking device to a transport box that transports it to a material testing site.

[0018] The steel bar gripping device 3 can grip steel bars S of a plurality of different sizes with a circular cross-section by size, and includes a mounting portion 4 attached to the tip of the robot arm 2, and one-side arm 5a and the other-side arm 5b that are attached to the mounting portion 4 so as to be movable toward and away from each other.

[0019] The steel bar gripping device 3 can grip steel bars S of a plurality of different sizes with a circular cross-section by size. In the present embodiment, the diameter of the steel bar S to be gripped is φ16 mm, φ32 mm, φ50 mm, φ83 mm, φ90 mm, and the length of the steel bar S of each diameter size is between 100 mm and 600 mm. Then, the steel bar S gripped by the steel bar gripping device 3 is conveyed to the location described above by the robot device 1.

[0020] Further, the steel bar gripping device 3 includes one-side claw members 6a, 6a made of metal and the other-side claw members 6b attached to the one-side arm 5a and the other-side arm 5b that are movable toward and away from each other. Each of the one-side arm 5a and the other-side arm 5b is formed in a flat plate shape having a predetermined plate thickness, and is arranged to face each other such that the respective plate thickness directions are the longitudinal direction of the steel bar S. The one-side claw members 6a, 6a and the other-side claw members 6b grip the steel bar S of the size to be gripped among the plurality of sizes of steel bars S (the steel bars S with the diameters φ16 mm, φ32 mm, φ50 mm, φ83 mm, φ90 mm described above) when the one-side arm 5a and the other-side arm 5b move in a direction approaching each other.

[0021] Here, as shown in FIG. 1, two one-side claw members 6a, 6a are attached at predetermined intervals along the longitudinal direction of the steel bar S to be gripped with respect to the one-side arm 5a. Specifically, the two one-side claw members 6a, 6a are attached to both side surfaces in the longitudinal direction of the one-side arm 5a (both side surfaces facing each other along the longitudinal direction of the steel bar S). Further, one other-side claw member 6b is attached to the other-side arm 5b. Specifically, one other-side claw member 6b is attached to the inner side surface of the other-side arm 5b (the side surface on the side of the opposing one-side arm 5a). For this reason, the two one-side claw members 6a, 6a and the one other-side claw member 6b are arranged in a stagger pattern along the longitudinal direction of the steel bar S to be gripped.

[0022] In addition, the material of each of the one-side claw members 6a, 6a and the other-side claw member 6b is made of metal, for example, a steel material such as stainless steel. Thereby, the one-side claw members 6a, 6a and the other-side claw member 6b have heat resistance, so they can be applied even when the work to be gripped has a temperature in the range of normal temperature to about 700 °C, and the sample of the steel bar S taken for material testing etc. can be handled.

[0023] Further, as shown in FIG. 2, each of the one-side claw members 6a, 6a and the other-side claw member 6b has a recess 7 having a radius of curvature R1 larger than the radius (45 mm) of the steel bar S having the largest diameter among the plurality of sizes of steel bars (in this embodiment, the steel bar S having the largest diameter among the steel bars S of φ16 mm, φ32 mm, φ50 mm, φ83 mm, and φ90 mm (the steel bar with a diameter of φ90 mm)). And in this recess 7, a plurality (nine in this embodiment) of protrusions 8 1 ~8 9 are formed.

[0024] And the plurality of protrusions 8 1 ~8 9The shape and arrangement are such that, when gripping the steel bar S with the claw members 6a, 6a on one side and the claw members 6b on the other side, they come into contact with all of the steel bars S of multiple sizes (in this embodiment, steel bars S with diameters of φ16 mm, φ32 mm, φ50 mm, φ83 mm, and φ90 mm) at two or more contact points.

[0025] Fig. 3 shows an example of gripping steel bars of multiple different diameters with the claw members 6a, 6a on one side and the claw members 6b on the other side. Fig. 3(a) shows a state of gripping a steel bar S with a minimum diameter of φ16 mm, Fig. 3(b) shows a state of gripping a steel bar S with a diameter of φ83 mm, and Fig. 3(c) shows a state of gripping a steel bar S with a maximum diameter of φ90 mm. When gripping a steel bar S with a minimum diameter of φ16 mm with the claw members 6a, 6a on one side and the claw members 6b on the other side, as shown in Fig. 3(a), for the steel bar S with a diameter of φ16 mm, the protrusions 8 at the lowermost positions of the respective claw members 6a, 6a, 6b 9 of the inclined surface 8 91 and its protrusion 8 9 the protrusion 8 adjacent to it 8 of the inclined surface 8 81 are in contact at two points.

[0026] Also, when gripping a steel bar S with a diameter of φ83 mm with the claw members 6a, 6a on one side and the claw members 6b on the other side, as shown in Fig. 3(b), for the steel bar S with a diameter of φ83 mm, it comes into contact at two or more points of the vertices of the protrusions 8 1 ~8 7 from above to below. Furthermore, when gripping a steel bar S with a maximum diameter of φ90 mm with the claw members 6a, 6a on one side and the claw members 6b on the other side, as shown in Fig. 3(c), for the steel bar S with a diameter of φ90 mm, it comes into contact at two or more points of the vertices of the protrusions 8 1 ~8 8 from above to below.

[0027] Thus, according to the bar steel gripping device 3 according to this embodiment, on each of the one-side arm 5a and the other-side arm 5b that face each other and are movable so as to be separable, there are attached metal one-side claw members 6a, 6a and the other-side claw members 6b that grip the bar steel S of the size to be gripped among the bar steels S of a plurality of sizes when the one-side arm 5a and the other-side arm 5b move in a direction approaching each other. And each of the one-side claw members 6a, 6a and the other-side claw members 6b has a depression 7 having a curvature radius R1 larger than the radius of the bar steel S having the largest diameter among the bar steels S of a plurality of sizes, and in the depression 7, there are a plurality of protrusions 8 1 ~8 9 are formed. And in each of the one-side claw members 6a, 6a and the other-side claw members 6b, the plurality of protrusions 8 1 ~8 9 are shaped and arranged such that when gripping the bar steel S, they contact all of the bar steels S of a plurality of sizes with two or more contact points.

[0028] Thereby, no matter which size of the bar steels S of a plurality of sizes is gripped, the one-side claw members 6a, 6a and the other-side claw members 6b contact with two or more contact points. For this reason, for bar steels S of a plurality of different diameters, even when the gripping position of the bar steel S is displaced from the assumed position in the longitudinal direction of the bar steel S, it is possible to stably grip each size. Also, since the material of each of the one-side claw members 6a, 6a and the other-side claw members 6b is made of metal, it has heat resistance, and it can be gripped regardless of whether the bar steel S to be gripped is at a low temperature or at a high temperature (for example, room temperature to about 700°C).

[0029] Also, according to the bar steel gripping device 3 according to this embodiment, two one-side claw members 6a, 6a are attached to the one-side arm 5a at a predetermined interval along the longitudinal direction of the bar steel S to be gripped, the other-side claw member 6b is attached to the other-side arm 5b as one, and the two one-side claw members 6a, 6a and the one other-side claw member 6b are arranged in a stagger pattern along the longitudinal direction of the bar steel S to be gripped.

[0030] As a result, when the arm 5a on one side and the arm 5b on the other side move in a direction approaching each other, the claw members 6a, 6a on one side and the claw member 6b on the other side do not come into contact with each other, and the round steel bar S with a smaller diameter can be accurately gripped by the claw members 6a, 6a on one side and the claw member 6b on the other side.

[0031] Further, according to the round steel bar gripping method according to the present embodiment, the round steel bar S of the size to be gripped among a plurality of round steel bars S having different diameters and a circular cross section is gripped using the round steel bar gripping device 3. As a result, for a plurality of round steel bars S having different diameters, regardless of whether the round steel bar S is at a low temperature or a high temperature, even if the gripping position of the round steel bar S is deviated from the assumed position in the longitudinal direction of the round steel bar S, it is possible to stably grip each size.

[0032] Further, according to the round steel bar conveying method according to the present embodiment, the round steel bar S of the size to be gripped among a plurality of round steel bars S having different diameters and a circular cross section is gripped using the round steel bar gripping device 3, and the round steel bar S gripped by the round steel bar gripping device 3 is conveyed by the robot device 1. As a result, for a plurality of round steel bars S having different diameters, regardless of whether the round steel bar S is at a low temperature or a high temperature, even if the gripping position of the round steel bar S is deviated from the assumed position in the longitudinal direction of the round steel bar S, it is possible to stably grip each size and convey the gripped round steel bar S.

[0033] Next, the round steel bar gripping device according to the reference example will be described with reference to FIGS. 4 and 5. FIG. 4 is an enlarged front view of the claw members 16a, 16a on one side and the claw member 16b on the other side provided in the round steel bar gripping device according to the reference example. FIG. 5 shows an example of gripping round steel bars S having different diameters by the claw members 16a, 16a on one side and the claw member 16b on the other side shown in FIG. 4. (a) is a front view showing a state of gripping a round steel bar S with a minimum diameter of φ16 mm, (b) is a front view showing a state of gripping a round steel bar S with a diameter of φ83 mm, and (c) is a front view showing a state of gripping a round steel bar S with a maximum diameter of φ90 mm.

[0034] Each of the claw members 16a, 16a on one side and the claw member 16b on the other side shown in FIG. 4 is different from each of the claw members 6a, 6a on one side and the claw member 6b on the other side in the steel bar gripping device 3 according to the embodiment shown in FIG. 2, and each has a plurality (four in this reference example) of curved recesses 17 for receiving steel bars S with different diameters. 1 ~17 4 is provided. And between adjacent curved recesses 17 1 ,17 2 :17 2 ,17 3 :17 3 ,17 4 , a protrusion 18 1 ,18 2 ,18 3 is formed.

[0035] Regarding the plurality of curved recesses 17 1 ~17 4 , the plurality of curved recesses 17 1 ~17 4 are sequentially arranged from top to bottom in each of the claw members 16a, 16a, 16b, and are set such that the radius of curvature gradually decreases from top to bottom. And among the plurality of sizes of steel bars S to be gripped, the steel bar S with the largest diameter is received and gripped by the uppermost curved recess 17 1 , and the steel bar S with the smallest diameter is received and gripped by the lowermost curved recess 17 4 .

[0036] Here, when gripping a steel bar S with a minimum diameter of φ16 mm by the claw members 16a, 16a on one side and the claw member 16b on the other side, as shown in FIG. 5(a), it is in surface contact with the curved surface of the lowermost curved recess 17 4 of each of the claw members 16a, 16a, 16b with respect to the steel bar S of φ16 mm. Also, when gripping a steel bar S with a maximum diameter of φ90 mm by the claw members 16a, 16a on one side and the claw member 16b on the other side, as shown in FIG. 5(c), it is in surface contact with the curved surface of the uppermost curved recess 17 1 of each of the claw members 16a, 16a, 16b with respect to the steel bar S of φ90 mm.

[0037] On the other hand, when gripping a steel bar S with a diameter of φ83 mm by the claw members 16a, 16a on one side and the claw members 16b on the other side, as shown in Fig. 5(b), the steel bar S with a diameter of φ80 mm is placed in the curved recess 17 1 ~17 4 and cannot be received by any of them, and contacts the steel bar S with a diameter of φ83 mm at one point of the protrusion 18 formed by the curved recess 17 1 adjacent to the curved recess 17 2 and the curved recess 17 1 In this case, when gripping the steel bar S with a diameter of φ83 mm among the steel bars S of multiple sizes (steel bars S with diameters of φ16 mm, φ83 mm, and φ90 mm), it is not stable. Therefore, for all of the steel bars S of multiple different diameters, even when the gripping position of the steel bar S is displaced from the assumed position in the longitudinal direction of the steel bar S, it is not possible to stably grip each size.

[0038] On the other hand, in the case of each of the claw members 6a, 6a on one side and the claw members 6b on the other side in the steel bar gripping device 3 according to the present embodiment, the shapes and arrangements of the plurality of protrusions 8 1 ~8 9 are such that when gripping the steel bar S by the claw members 6a, 6a on one side and the claw members 6b on the other side, they contact all of the steel bars S of multiple sizes with two or more contact points. Therefore, no matter which size of the steel bar S among the steel bars S of multiple sizes is gripped, the claw members 6a, 6a on one side and the claw members 6b on the other side contact with two or more contact points, and for the steel bars S of multiple different diameters, even when the gripping position of the steel bar S is displaced from the assumed position in the longitudinal direction of the steel bar S, it is possible to stably grip each size.

[0039] Next, the bar steel gripping device according to the modified example will be described with reference to FIGS. 6 and 7. FIG. 6 is an enlarged front view of one-side claw members 6a, 6a and the other-side claw member 6b provided in the bar steel gripping device according to the modified example. FIG. 7 shows an example of gripping bar steels S of a plurality of different diameters by the one-side claw members 6a, 6a and the other-side claw member 6b shown in FIG. 6. (a) is a front view showing a state of gripping a bar steel S having a minimum diameter of φ16 mm, (b) is a front view showing a state of gripping a bar steel S having a diameter of φ83 mm, and (c) is a front view showing a state of gripping a bar steel S having a maximum diameter of φ90 mm.

[0040] Each of the one-side claw members 6a, 6a and the other-side claw member 6b shown in FIG. 6 has a recess 9 having a curvature radius R2 larger than the radius of the bar steel S having the largest diameter among the bar steels of a plurality of sizes, similarly to each of the one-side claw members 6a, 6a and the other-side claw member 6b in the bar steel gripping device 3 according to the embodiment shown in FIG. 2. Also in this modified example, bar steels S having diameters of φ16 mm, φ32 mm, φ50 mm, φ83 mm, and φ90 mm are the gripping targets. And in this recess 9, a plurality (five in this modified example) of protrusions 10 1 ~10 5 are formed.

[0041] And the plurality of protrusions 10 1 ~10 5 in each of the one-side claw members 6a, 6a and the other-side claw member 6b are shaped and arranged such that they contact with two or more contact points for all bar steels S of a plurality of sizes (bar steels S of φ16 mm, φ32 mm, φ50 mm, φ83 mm, and φ90 mm in this modified example) when gripping the bar steel S by the one-side claw members 6a, 6a and the other-side claw member 6b.

[0042] Here, when gripping a bar steel S having a minimum diameter of φ16 mm by the one-side claw members 6a, 6a and the other-side claw member 6b, as shown in FIG. 7(a), for the bar steel S having a diameter of φ16 mm, the inclined surface 10 5 of the protrusion 10 51 at the lowermost part of each of the claw members 6a, 6a, 6b and its protrusion 10 5The protrusions 10 adjacent to 4 the inclined surface 10 of 41 are in contact at two points. Also, when gripping a steel bar S with a diameter of φ83 mm by the claw members 6a, 6a on one side and the claw members 6b on the other side, as shown in Fig. 7(b), with respect to the steel bar S with a diameter of φ83 mm, the protrusions 10 2 and 10 3 are in contact at two points at the vertices.

[0043] Furthermore, when gripping a steel bar S with a maximum diameter of φ90 mm by the claw members 6a, 6a on one side and the claw members 6b on the other side, as shown in Fig. 7(c), with respect to the steel bar S with a diameter of φ90 mm, the protrusions 10 2 and 10 3 are in contact at three points at the vertices of and the inclined surface 10 of the protrusion 10 1 the inclined surface 10 of 11 are in contact at three points.

[0044] In the case of the steel bar gripping device according to this modification example, for each of the claw members 6a, 6a on one side and the claw members 6b on the other side in the steel bar gripping device 3 according to the embodiment shown in Fig. 2, the number of the protrusions 10 1 ~10 5 is small. However, similar to the embodiment shown in Fig. 2, the shapes and arrangements of the plurality of protrusions 10 1 ~10 5 in each of the claw members 6a, 6a on one side and the claw members 6b on the other side are such that they are in contact with all steel bars S of a plurality of sizes at two or more contact points when gripping the steel bar S.

[0045] As a result, regardless of the size of the steel bar S among the plurality of sizes of steel bars S to be gripped, the claw members 6a, 6a on one side and the claw members 6b on the other side contact with two or more contact points. For this reason, regarding the plurality of sizes of steel bars S with different diameters, even when the gripping position of the steel bar S is displaced from the assumed position in the longitudinal direction of the steel bar S, it is possible to stably grip each size. Further, the material of each of the claw members 6a, 6a on one side and the claw members 6b on the other side is made of metal, similar to each of the claw members 6a, 6a on one side and the claw members 6b on the other side in the steel bar gripping device 3 according to the embodiment shown in FIG. 2, so it has heat resistance and can be gripped regardless of whether the steel bar S to be gripped is at a low temperature or a high temperature (for example, normal temperature to about 700°C).

[0046] As described above, the embodiments of the present invention have been described, but the present invention is not limited to this and various changes and improvements can be made. For example, the protrusions 8 formed on each of the claw members 6a, 6a on one side and the claw members 6b on the other side 1 ~8 9 ,10 1 ~10 5 The number of is not limited to 9 shown in FIG. 2 or 5 shown in FIG. 6, and any plurality is acceptable.

[0047] Further, the plurality of protrusions 8 formed on each of the claw members 6a, 6a on one side and the claw members 6b on the other side 1 ~8 9 ,10 1 ~10 5 The shape and arrangement are not limited to the shape and arrangement shown in FIGS. 2 and 6, and any shape and arrangement may be used as long as they contact all of the plurality of sizes of steel bars S with two or more contact points when gripping the steel bar S by the claw members 6a, 6a on one side and the claw members 6b on the other side.

[0048] Further, the diameter of the steel bar S to be gripped is not limited to φ16mm, φ32mm, φ50mm, φ83mm, φ90mm, and the length of the steel bar S is not limited to 100mm to 600mm. Further, the two one-side claw members 6a, 6a and the one other-side claw member 6b are arranged in a staggered pattern along the longitudinal direction of the steel bar S. However, the one-side claw members and the other-side claw member do not necessarily have to be arranged in a staggered pattern.

[0049] Moreover, the use of the robot device 1 equipped with the steel bar gripping device 3 is not limited to the use of transporting a sample of the steel bar S taken from a hot-rolled steel bar for material testing or the like to a marking device (not shown), or the use of transporting a sample marked by the marking device to a transport box for transporting it to a material testing site.

Example

[0050] In the comparative example, the one-side claw member and the other-side claw member provided in the steel bar gripping device according to the first inventive example and the second inventive example, the central portion in the longitudinal direction of the steel bar samples with diameters of φ16mm, φ32mm, φ50mm, φ83mm, and φ90mm, the position shifted 10 mm in the longitudinal direction from the central portion, and the position shifted 20 mm in the longitudinal direction from the central portion were gripped and lifted, and the inclination of the steel bar sample with respect to the horizontal was measured.

[0051] The one-side claw member and the other-side claw member provided in the steel bar gripping device according to the comparative example have the same shape as the one-side claw members 16a, 16a and the other-side claw member 16b provided in the steel bar gripping device according to the reference example shown in FIG. 4.

[0052] Moreover, the one-side claw member and the other-side claw member provided in the steel bar gripping device according to the first inventive example have the same shape as the one-side claw members 6a, 6a and the other-side claw member 6b provided in the steel bar gripping device according to the embodiment shown in FIG. 2. Furthermore, the one-side claw member and the other-side claw member provided in the steel bar gripping device according to the second inventive example have the same shape as the one-side claw members 6a, 6a and the other-side claw member 6b provided in the steel bar gripping device according to the modified example shown in FIG. 6.

[0053] Fig. 8 shows the measurement results of the inclination of a steel bar sample with diameters of φ16 mm, φ32 mm, φ50 mm, φ83 mm, and φ90 mm with respect to the horizontal when the central portion in the longitudinal direction of the steel bar sample is gripped and lifted by the claw members on one side and the claw members on the other side provided in the steel bar gripping device according to the comparative example, Invention Example 1, and Invention Example 2.

[0054] Also, Fig. 9 shows the measurement results of the inclination of a steel bar sample with diameters of φ16 mm, φ32 mm, φ50 mm, φ83 mm, and φ90 mm with respect to the horizontal when a position 10 mm displaced in the longitudinal direction from the central portion in the longitudinal direction of the steel bar sample is gripped and lifted by the claw members on one side and the claw members on the other side provided in the steel bar gripping device according to the comparative example, Invention Example 1, and Invention Example 2. Furthermore, Fig. 10 shows the measurement results of the inclination of a steel bar sample with diameters of φ16 mm, φ32 mm, φ50 mm, φ83 mm, and φ90 mm with respect to the horizontal when a position 20 mm displaced in the longitudinal direction from the central portion in the longitudinal direction of the steel bar sample is gripped and lifted by the claw members on one side and the claw members on the other side provided in the steel bar gripping device according to the comparative example, Invention Example 1, and Invention Example 2.

[0055] In the case of the claw members on one side and the claw members on the other side provided in the steel bar gripping device according to the comparative example, as shown in Fig. 10, when a position 20 mm displaced in the longitudinal direction from the central portion in the longitudinal direction of the steel bar sample was gripped, the inclination of the steel bar sample with a diameter of φ50 mm became as large as 25°, resulting in an unstable state. Also, in the case of the claw members on one side and the claw members on the other side provided in the steel bar gripping device according to the comparative example, as shown in Fig. 8, even when the central portion in the longitudinal direction of the steel bar sample was gripped, the inclination of the steel bar sample with a diameter of φ83 mm became as large as 24°, resulting in an unstable state.

[0056] On the other hand, in the case of the one-side claw member and the other-side claw member provided in the bar steel gripping device according to Example 1 of the present invention, as shown in FIGS. 8 to 10, in any case where it is desired to grip the central portion in the longitudinal direction of bar steel samples with diameters of φ16 mm, φ32 mm, φ50 mm, φ83 mm, and φ90 mm, a position shifted 10 mm in the longitudinal direction from the central portion, and a position shifted 20 mm in the longitudinal direction from the central portion, it could be stably gripped with an inclination of 5° or less.

[0057] Also, in the case of the one-side claw member and the other-side claw member provided in the bar steel gripping device according to Example 2 of the present invention, as shown in FIG. 9, when gripping a position shifted 10 mm in the longitudinal direction from the central portion in the longitudinal direction of the bar steel sample, the inclination was slightly large at 12° for the bar steel sample with a diameter of φ83 mm. Further, as shown in FIG. 10, when gripping a position shifted 20 mm in the longitudinal direction from the central portion in the longitudinal direction of the bar steel sample, the inclination was slightly large at 13° for the bar steel sample with a diameter of φ83 mm. However, these inclinations were smaller and could be stably gripped compared to the comparative example.

Explanation of Signs

[0058] 1 Robot device (bar steel transfer device) 2 Robot arm 3 Bar steel gripping device 4 Mounting part 5a One-side arm 5b Other-side arm 6a One-side claw member 6b Other-side claw member 7 Depression 8 1 ~8 9 Projection 9 Depression 10 1 ~10 5 Projection 16a One-side claw member 16b Other-side claw member 17 1 ~17 4 Curved recess 18 1 ~18 2 Protrusion S Bar steel

Claims

1. A bar gripping device capable of gripping a plurality of sizes of bar having different diameters each having a circular cross section, The one-side claw member and the other-side claw member are attached to the one-side arm and the other-side arm, respectively, which are opposed to each other and move toward and away from each other, and which grip a steel bar of a size to be gripped among the plurality of sizes of steel bars when the one-side arm and the other-side arm move in a direction approaching each other, Each of the claw members on one side and the claw members on the other side has a recess having a radius of curvature larger than the radius of the steel bar having the largest diameter among the steel bars of the plurality of sizes, and a plurality of protrusions are formed in the recess, A bar steel gripping device characterized in that the shape and arrangement of the multiple protrusions on each of the claw members on one side and the claw members on the other side are shaped and arranged so that when the claw members on one side and the claw members on the other side grip the bar steel, they contact all of the multiple sizes of bar steel at two or more contact points.

2. The bar steel gripping device of claim 1, characterized in that two of the claw members on one side are attached to the arm on one side at a predetermined interval along the longitudinal direction of the bar steel to be gripped, and one claw member on the other side is attached to the arm on the other side, and the two claw members on one side and one claw member on the other side are staggered along the longitudinal direction of the bar steel to be gripped.

3. A method for gripping a steel bar, comprising the steps of: gripping a steel bar of a size to be gripped among a plurality of steel bars of different sizes each having a circular cross section and different diameters, using the steel bar gripping device according to claim 1 or 2.

4. A method for transporting steel bars, comprising the steps of: using the steel bar gripping device according to claim 1 or 2 to grip a steel bar of a size to be gripped among a plurality of sizes of steel bars having circular cross sections and different diameters; and transporting the steel bar gripped by the steel bar gripping device by a robot device.

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