Protective steel bar production welding device

Abstract

The utility model discloses a protective reinforcing steel bar production welding device, which relates to the technical field of reinforcing steel bar welding, and comprises a workbench, a plurality of supporting legs and a plurality of supporting rods, the box bodies are symmetrically arranged at two ends of the top end of the workbench; the reinforcing steel bar clamping and overturning mechanism is arranged in the box body in a penetrating manner; the welding protection mechanism is arranged between the two groups of reinforcing steel bar clamping and overturning mechanisms; the mechanical arm is arranged on one side of the welding protection mechanism, and a welding head is arranged at the output end of the mechanical arm; and the control box is arranged on one side of one group of reinforcing steel bar clamping and overturning mechanisms. The protective steel bar production welding device is reasonable, reliable and easy and convenient to operate, has remarkable advantages in the aspects of production efficiency and welding quality, is high in practicability and can effectively improve the integrity and reliability of welding.

Description

Technical Field

[0001] This utility model relates to the field of steel bar welding technology, and more specifically, to a protective steel bar production and welding device. Background Technology

[0002] Construction is a production activity carried out by people using various building materials and machinery according to specific design blueprints within a certain space and time to build various types of building products. Reinforcing steel is a common building material in construction. It refers to steel used in reinforced concrete and prestressed reinforced concrete. Reinforcing steel is an indispensable component in construction. During the production and processing of reinforcing steel, users need to use welding equipment to weld adjacent reinforcing steel bars together.

[0003] However, in the steel bar production and processing stage, welding equipment is often used to weld adjacent steel bars together. However, existing welding equipment has many drawbacks in practical applications. On the one hand, it is difficult to maintain a stable state during welding, and the lack of a flexible flipping mechanism makes it difficult to accurately control the welding position, significantly reducing welding quality and seriously affecting the overall strength and structural stability of the steel bars, posing safety hazards for subsequent construction. On the other hand, the welding process generates a large amount of spatter, which not only pollutes the surrounding environment and increases the difficulty and cost of cleanup, but also causes strong direct light exposure during welding. Prolonged exposure to this environment can severely irritate the eyes of operators, easily leading to vision problems and other eye diseases, thus harming their health.

[0004] There are currently no effective solutions to the problems in the relevant technologies. Utility Model Content

[0005] In view of the problems in the related technologies, this utility model proposes a protective steel bar production and welding device to overcome the above-mentioned technical problems existing in the existing related technologies.

[0006] Therefore, the specific technical solution adopted by this utility model is as follows:

[0007] A protective rebar production welding device includes: a workbench with several support legs at its bottom; a box symmetrically arranged at both ends of the top of the workbench; a rebar clamping and flipping mechanism inserted inside the box; a welding protection mechanism located between two sets of rebar clamping and flipping mechanisms; a robotic arm located on one side of the welding protection mechanism, with a welding head at its output end; and a control box located on one side of one set of rebar clamping and flipping mechanisms.

[0008] Furthermore, to achieve the clamping and flipping of the reinforcing bars, the first motor drives the reinforcing bars to rotate, and the second motor drives the reinforcing bars to clamp them, thereby ensuring the stability of the reinforcing bars during welding and guaranteeing the welding quality. The reinforcing bar clamping and flipping mechanism includes a sleeve inserted into the side wall of the box, a collar provided in the middle of the outer side of the sleeve, and a first gear sleeved on the outer side of one end of the sleeve; a first support plate connected to the inner wall of the box is provided on one side of the collar, a first motor is provided at the top of the first support plate, and a first gear meshing with the first gear is provided at one end of the output shaft of the first motor. The two gears have a second support plate connected to the inner wall of the housing on the other side of the collar. A second motor is installed at the top of the second support plate, and a worm gear is installed at one end of the output shaft of the second motor. A third gear is installed at one end of the collar, and a rotating rod is installed through the side wall of the third gear. A worm wheel that meshes with the worm gear is installed on the outer side of one end of the rotating rod. A clamping assembly is installed at the top of the other end of the collar. Limiting strips are symmetrically arranged on the outer side of the sleeve, and a flared mouth is provided at one end of the sleeve. Several annular racks that mesh with the third gear are arranged on the outer side of the collar, and limiting grooves that cooperate with the limiting strips are symmetrically opened on the inner wall of the collar.

[0009] Furthermore, to achieve the clamping of the reinforcing bar, the clamping assembly includes a fourth gear located at the top of the other end of the collar. Threaded rods are provided on both sides of the fourth gear. A driven ring is provided on the outer side of the threaded rod, and a clamping rod is provided on the outer side of the driven ring. The clamping rod has an L-shaped cross-section, and a clamping plate is provided at the bottom of one side of the clamping rod, with an arc-shaped cross-section. A rotating plate is provided on the outer side of the clamping rod and on the outer side of the sleeve, and the rotating plate is embedded in the side wall of the housing. A limiting hole is provided at the top of the side wall of the rotating plate, and the limiting hole has a square cross-section. An insert rod that passes through the outer side of the clamping rod is provided in the center of the limiting hole.

[0010] Furthermore, to protect the welding area, the protective cover can block the spatter generated during welding, preventing damage to the surrounding environment, operators, and other equipment components, thus providing reliable safety protection for welding operations. Simultaneously, it reduces eye strain from strong light, protecting the operator's vision. A collection trough facilitates the collection of welding slag, making subsequent workbench cleaning easier. The welding protection mechanism includes a fixed base positioned between two sets of rebar clamping and flipping mechanisms. A chamber is formed at the bottom of the fixed base, and symmetrical U-shaped frames penetrating the bottom sidewalls of the chamber are arranged inside. A drive rod is inserted through the middle of the U-shaped frame, with one end of the drive rod penetrating the sidewall of the fixed base and housing a third motor. Protective covers are installed at the top of both sides of the U-shaped frame. A collection trough is located at the top center of the fixed base. Threads are provided on the outer sides of both ends of the drive rod, with the two sets of threads in opposite directions. A threaded hole matching the threads is located in the middle of the U-shaped frame.

[0011] Furthermore, in order to achieve the fit between the welding heads and allow the welding heads to pass through the arc-shaped holes for welding, the top of the protective cover is provided with an arc-shaped structure, and one end of the adjacent top of the two sets of protective covers is provided with an arc-shaped hole.

[0012] The beneficial effects of this utility model are as follows:

[0013] 1. This utility model is reasonable and reliable, simple and convenient to operate, and the protective steel bar production and welding device has significant advantages in production efficiency and welding quality. It is highly practical and can effectively improve the integrity and reliability of welding.

[0014] 2. By setting up a rebar clamping and flipping mechanism, the rebar can be clamped and flipped. Driven by the first motor, the rebar can be rotated, and driven by the second motor, the rebar can be clamped, thereby ensuring the stability of the rebar during welding and ensuring the welding quality.

[0015] 3. By setting up a welding protection mechanism, the welding area is protected. The protective cover can block the spatter generated during the welding process, preventing these spatters from damaging the surrounding environment, operators, and other parts of the equipment, providing reliable safety protection for welding operations. At the same time, it can also reduce the stimulation of strong light to the eyes, protect the vision health of operators, and use the collection tank to collect welding slag, which facilitates the cleaning of the workbench later. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a structural schematic diagram of a protective steel bar production and welding device according to an embodiment of the present utility model;

[0018] Figure 2 This is a cross-sectional view of a steel bar clamping and flipping mechanism in a protective steel bar production and welding device according to an embodiment of the present utility model.

[0019] Figure 3 This is a partial schematic diagram of a steel bar clamping and flipping mechanism in a protective steel bar production and welding device according to an embodiment of the present utility model;

[0020] Figure 4 This is a schematic diagram of the welding protection mechanism in a protective steel bar production welding device according to an embodiment of the present utility model.

[0021] In the picture:

[0022] 1. Workbench; 2. Support leg; 3. Housing; 4. Rebar clamping and flipping mechanism; 401. Sleeve; 4011. Limiting strip; 4012. Trumpet mouth; 402. Collar; 4021. Ring rack; 4022. Limiting groove; 403. First gear; 404. First support plate; 405. First motor; 406. Second gear; 407. Second support plate; 408. Second motor; 409. Worm gear; 410. Third gear; 411. Rotating rod; 412. Worm wheel; 413. Clamping assembly; 4131 4132. Threaded rod; 4133. Driven ring; 4134. Clamping rod; 4135. Clamping plate; 4136. Rotating plate; 41361. Limiting hole; 41362. Inserting rod; 5. Welding protection mechanism; 501. Fixed seat; 502. Chamber; 503. U-shaped frame; 5031. Threaded hole; 504. Drive rod; 5041. Thread; 505. Third motor; 506. Protective cover; 5061. Arc-shaped hole; 507. Collection trough; 6. Robotic arm; 7. Welding head; 8. Control box. Detailed Implementation

[0023] To further illustrate the various embodiments, the present invention provides accompanying drawings, which are part of the disclosure of the present invention. These drawings are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, those skilled in the art should be able to understand other possible implementation methods and the advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are usually used to represent similar components.

[0024] According to an embodiment of the present invention, a protective steel bar production and welding device is provided.

[0025] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments, such as... Figures 1-4 As shown, the protective steel bar production welding device according to an embodiment of the present utility model includes: a workbench 1, with a plurality of support legs 2 provided at the bottom end of the workbench 1; a box 3, symmetrically arranged at both ends of the top of the workbench 1; a steel bar clamping and flipping mechanism 4, inserted inside the box 3; a welding protection mechanism 5, arranged between two sets of steel bar clamping and flipping mechanisms 4; a robotic arm 6, arranged on one side of the welding protection mechanism 5, with a welding head 7 provided at the output end of the robotic arm 6; and a control box 8, arranged on one side of one set of steel bar clamping and flipping mechanisms 4.

[0026] Furthermore, it should be noted that the control box 8 contains a PLC control system, and the rebar clamping and flipping mechanism 4, welding protection mechanism 5, robotic arm 6, and welding head 7 are sequentially electrically connected to the control box 8. The PLC possesses powerful logic operation and judgment capabilities. It can monitor the working status and feedback signals of each mechanism in real time. The PLC control system of the control box 8 has a communication interface, which can interact with other devices or systems. For example, it can communicate with a host computer, uploading data from the welding process to the host computer software in real time, facilitating remote monitoring and management by operators. The control box 8 is typically equipped with an operation panel, allowing operators to set parameters, select programs, start and stop equipment, and perform other operations on the PLC control system through the operation panel.

[0027] The welding head 7 is mounted on the output end of the robotic arm 6. Through the motion control of the robotic arm 6, the welding head 7 can move precisely in three-dimensional space. The robotic arm 6, according to instructions from the PLC control system, drives the welding head 7 to weld the reinforcing bars. Additionally, a wire feeder (not shown in the figure, this is existing technology and will not be elaborated further) is externally configured to the welding head 7. The wire feeder can precisely control the wire feeding speed based on parameters such as the welding current and voltage of the welding head 7. The wire feeder and the welding head 7 are connected via electrical and signal lines to achieve real-time data transmission and collaborative control. For example, signals from the temperature and current sensors of the welding head 7 can be fed back to the wire feeder, which adjusts the wire feeding parameters accordingly. Simultaneously, the operating status signal of the wire feeder can also be transmitted to the PLC control system for monitoring and management of the entire welding process.

[0028] With the help of the above-mentioned technical solution of this utility model, this utility model is reasonable and reliable, simple and convenient to operate, and the protective steel bar production and welding device has significant advantages in production efficiency and welding quality. It is highly practical and can effectively improve the integrity and reliability of welding.

[0029] In one embodiment, the rebar clamping and flipping mechanism 4 includes a sleeve 401 inserted into the side wall of the housing 3. A collar 402 is provided at the middle of the outer side of the sleeve 401, and a first gear 403 is sleeved on the outer side of one end of the sleeve 401. A first support plate 404 connected to the inner wall of the housing 3 is provided on one side of the collar 402. A first motor 405 is provided at the top of the first support plate 404. A second gear 406 meshing with the first gear 403 is provided at one end of the output shaft of the first motor 405. A second support plate 407 connected to the inner wall of the housing 3 is provided on the other side of the collar 402. A second motor 406 is provided at the top of the second support plate 407. 08. A worm gear 409 is provided at one end of the output shaft of the second motor 408; a third gear 410 is provided at one end of the top of the collar 402, and a rotating rod 411 is provided through the side wall of the third gear 410. In addition, in specific applications, the rotating rod 411 is connected to the inner wall of the housing 3 by a bearing. A worm wheel 412 that meshes with the worm gear 409 is provided on the outer side of one end of the rotating rod 411. A clamping assembly 413 is provided at the top of the other end of the collar 402; limit strips 4011 are symmetrically provided on the outer side of the sleeve 401, and a flared mouth 4012 is provided at one end of the sleeve 401; several annular racks 4021 that mesh with the third gear 410 are provided on the outer side of the collar 402. The inner wall of 402 is symmetrically provided with limiting grooves 4022 that cooperate with the limiting strip 4011; the clamping assembly 413 includes a fourth gear 4131 disposed at the top of the other end of the collar 402, threaded rods 4132 are provided on both sides of the fourth gear 4131, a driven ring 4133 is provided on the outer side of the threaded rod 4132, and a clamping rod 4134 is provided on the outer side of the driven ring 4133. The clamping rod 4134 has an L-shaped cross-section, and a clamping plate 4135 is provided on the bottom of one side of the clamping rod 4134, and the clamping plate 4135 has an arc-shaped cross-section; a rotating plate 4136 is provided on the outer side of the clamping rod 4134 and located on the outer side of the sleeve 401. In addition, in specific applications, the upper... The rotating plate 4136 is fixedly connected to the sleeve 401, and the rotating plate 4136 is connected to the side wall of the housing 3 by a bearing, and the rotating plate 4136 is embedded in the side wall of the housing 3; a limiting hole 41361 is opened at the top of the side wall of the rotating plate 4136, and the cross-section of the limiting hole 41361 is a square structure. An insert rod 41362 is provided in the middle of the limiting hole 41361, which is inserted through the outside of the clamping rod 4134, thereby realizing the clamping and flipping of the reinforcing bar. Under the drive of the first motor 405, the reinforcing bar can be driven to rotate. Under the drive of the second motor 408, the reinforcing bar can be clamped, thereby ensuring the stability of the reinforcing bar during welding and ensuring the welding quality.

[0030] The working principle of the rebar clamping and flipping mechanism 4 is as follows: First, the operator can conveniently insert the rebar into the box 3 through the flared mouth 4012. When it is necessary to clamp the rebar, the operator starts the second motor 408. The output shaft of the second motor 408 drives the worm 409 to rotate. Then, under the meshing action of the worm 409 and the worm wheel 412, the rotating rod 411 is driven to rotate, which in turn drives the third gear 410 to rotate. Then, under the meshing action of the third gear 410 and the ring rack 4021 on the collar 402, and under the cooperation of the limiting groove 4022 and the limiting strip 4011, the collar 402 is driven to move linearly on the sleeve 401, which in turn drives the fourth gear 4131 to rotate, which in turn drives the threaded rod 4132 to rotate. Under the cooperation of the threaded rod 4132 and the driven ring 4133, the driven ring 4133 is driven to move, which in turn drives the clamping plate 4135 to clamp the rebar through the clamping rod 4134, ensuring the stability of the rebar during welding.

[0031] When it is necessary to flip the steel bar, the first motor 405 drives the second gear 406 to rotate, which in turn drives the first gear 403 to rotate, which in turn drives the sleeve 401 to rotate, and then the collar 402 and the rotating plate 4136 to rotate. Thus, with the cooperation of the insertion rod 41362 and the clamping rod 4134, the clamping plate 4135 is driven to rotate, thereby realizing the flipping of the steel bar.

[0032] In one embodiment, the welding protection mechanism 5 includes a fixed base 501 disposed between two sets of steel bar clamping and flipping mechanisms 4. A chamber 502 is formed at the bottom of the fixed base 501. U-shaped frames 503, penetrating the bottom sidewalls of the chamber 502, are symmetrically arranged inside the chamber 502. A drive rod 504 is passed through the middle of the U-shaped frame 503. One end of the drive rod 504 passes through the sidewall of the fixed base 501 and is equipped with a third motor 505. Protective covers 506 are provided at the top of both sides of the U-shaped frame 503. A material collection trough 507 is formed at the top center of the fixed base 501. Threads 5041 are provided on the outer sides of both ends of the drive rod 504, and two sets of threads 504... The directions of 1 are opposite; the U-shaped frame 503 has a threaded hole 5031 in the middle that mates with the thread 5041; the top of the protective cover 506 is provided with an arc-shaped structure, and the top of the adjacent protective covers 506 has an arc-shaped hole 5061, thereby achieving protection of the welding area. Under the action of the protective cover 506, it can block the spatter generated during the welding process, and prevent these spatters from damaging the surrounding environment, operators and other parts of the equipment, providing reliable safety protection for welding operations. At the same time, it can also reduce the stimulation of strong light to the eyes, protect the visual health of operators, and use the collection trough 507 to collect part of the welding slag, which is convenient for cleaning the workbench 1 later.

[0033] The working principle of the welding protection mechanism 5 is as follows: the output shaft of the third motor 505 drives the drive rod 504 to rotate, and then, with the cooperation of the thread 5041 and the threaded hole 5031, it drives the two sets of U-shaped frames to move towards the middle of the fixed seat 501, and then drives the protective cover 506 to move towards the middle. After the two sets of protective covers 506 come into contact, the rotation of the third motor 505 stops, and then welding protection can be achieved through the two sets of protective covers 506.

[0034] To facilitate understanding of the above-mentioned technical solutions of this utility model, the working principle or operation method of this utility model in actual process will be described in detail below.

[0035] In practical application, firstly, the worker inserts two sets of steel bars to be welded into one end of the steel bar clamping and flipping mechanism 4, so that the two sets of steel bars to be welded come into contact. Then, the steel bar clamping and flipping mechanism 4 clamps the steel bars. After clamping, the welding protection mechanism 5 protects the contact position of the steel bars. Then, the robotic arm 6 controls the welding head 7 to weld the steel bars to be welded. During welding, the welding protection mechanism 5 can block the spatter and strong light generated during the welding process, and the steel bar clamping and flipping mechanism 4 flips the steel bars. After welding, the worker can open the welding protection mechanism 5 to perform surface treatment on the weld. After the treatment is completed, the worker can remove the welded steel bars.

[0036] In summary, with the help of the above-mentioned technical solution of this utility model, this utility model is reasonable and reliable, simple and convenient to operate, and the protective rebar production and welding device has significant advantages in production efficiency and welding quality. It is highly practical and can effectively improve the integrity and reliability of welding. By setting the rebar clamping and flipping mechanism 4, the rebar is clamped and flipped. Driven by the first motor 405, the rebar can be rotated, and driven by the second motor 408, the rebar can be clamped, thereby ensuring the stability of the rebar during welding and ensuring welding quality. By setting the welding protection mechanism 5, the welding area is protected. Under the action of the protective cover 506, the spatter generated during the welding process can be blocked, preventing these spatters from damaging the surrounding environment, operators, and other parts of the equipment, providing reliable safety protection for welding operations. At the same time, it can also reduce the stimulation of strong light to the eyes, protect the vision health of operators, and use the collection trough 507 to collect part of the welding slag, which is convenient for cleaning the workbench 1 later.

[0037] In this utility model, unless otherwise explicitly specified and limited, the terms "installation", "setting", "connection", "fixing", "screw connection", etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0038] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A protective steel bar production and welding device, characterized in that, include: A workbench (1), and the bottom end of the workbench (1) is provided with several support legs (2). The box body (3) is symmetrically arranged at both ends of the top of the workbench (1); A steel bar clamping and flipping mechanism (4) is interspersed inside the box body (3); The welding protection mechanism (5) is located between the two sets of the steel bar clamping and flipping mechanisms (4); A robotic arm (6) is located on one side of the welding protection mechanism (5), and a welding head (7) is provided at the output end of the robotic arm (6). The control box (8) is located on one side of one of the steel bar clamping and flipping mechanisms (4).

2. The protective steel bar production and welding device according to claim 1, characterized in that, The steel bar clamping and flipping mechanism (4) includes a sleeve (401) inserted into the side wall of the box (3), a collar (402) is provided in the middle of the outer side of the sleeve (401), and a first gear (403) is sleeved on the outer side of one end of the sleeve (401). A first support plate (404) connected to the inner wall of the housing (3) is provided on one side of the collar (402). A first motor (405) is provided at the top of the first support plate (404). A second gear (406) meshing with the first gear (403) is provided at one end of the output shaft of the first motor (405). A second support plate (407) connected to the inner wall of the housing (3) is provided on the other side of the collar (402). A second motor (408) is provided at the top of the second support plate (407). A worm gear (409) is provided at one end of the output shaft of the second motor (408). A third gear (410) is provided at one end of the collar (402), and a rotating rod (411) is provided through the side wall of the third gear (410). A worm wheel (412) that meshes with the worm (409) is provided on the outer side of one end of the rotating rod (411), and a clamping assembly (413) is provided at the top of the other end of the collar (402).

3. The protective steel bar production and welding device according to claim 2, characterized in that, Limiting strips (4011) are symmetrically provided on the outer side of the sleeve (401), and a flared mouth (4012) is provided at one end of the sleeve (401).

4. The protective steel bar production and welding device according to claim 3, characterized in that, The outer side of the collar (402) is provided with a plurality of annular racks (4021) that mesh with the third gear (410), and the inner wall of the collar (402) is symmetrically provided with limiting grooves (4022) that cooperate with the limiting strip (4011).

5. A protective steel bar production and welding device according to claim 4, characterized in that, The clamping assembly (413) includes a fourth gear (4131) disposed at the top of the other end of the collar (402). Threaded rods (4132) are disposed on both sides of the fourth gear (4131). A driven ring (4133) is disposed on the outer side of the threaded rod (4132). A clamping rod (4134) is disposed on the outer side of the driven ring (4133). The clamping rod (4134) has an L-shaped cross-section. A clamping plate (4135) is disposed at the bottom of one side of the clamping rod (4134), and the clamping plate (4135) has an arc-shaped cross-section. A rotating plate (4136) is provided on the outside of the clamping rod (4134) and on the outside of the sleeve (401), and the rotating plate (4136) is embedded in the side wall of the box (3).

6. The protective steel bar production and welding device according to claim 5, characterized in that, The rotating plate (4136) has a limiting hole (41361) on the top of its side wall, and the limiting hole (41361) has a square cross-section. A plug (41362) is provided in the middle of the limiting hole (41361) and passes through the outside of the clamping rod (4134).

7. The protective steel bar production and welding device according to claim 1, characterized in that, The welding protection mechanism (5) includes a fixed seat (501) disposed between two sets of the steel bar clamping and flipping mechanisms (4). A cavity (502) is opened at the bottom of the fixed seat (501). A U-shaped frame (503) is symmetrically arranged inside the cavity (502) and passes through the bottom side wall of the cavity (502). A drive rod (504) is provided through the middle of the U-shaped frame (503). One end of the drive rod (504) passes through the side wall of the fixed base (501) and is provided with a third motor (505). Protective covers (506) are provided at the top of both sides of the U-shaped frame (503). The top center of the fixed base (501) is provided with a material collection trough (507).

8. A protective steel bar production and welding device according to claim 7, characterized in that, Both ends of the drive rod (504) are provided with threads (5041), and the two sets of threads (5041) are in opposite directions.

9. A protective steel bar production and welding device according to claim 8, characterized in that, The U-shaped frame (503) has a threaded hole (5031) in the middle that matches the thread (5041).

10. A protective steel bar production and welding device according to claim 7, characterized in that, The top of the protective cover (506) is provided with an arc-shaped structure, and one end of the adjacent top of the two sets of protective covers (506) is provided with an arc-shaped hole (5061).

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