A charging pile with automatic cable recovery and storage structure

Abstract

The present invention discloses a charging pile with an automatic cable recovery and storage structure, comprising a charging pile body, and also comprising a storage motor, a rotating shaft, a limiting roller, a cable fixing column and a cable resetting mechanism; a built-in groove is opened in the rear side wall of the charging pile body, the storage motor is fixed in the built-in groove, the rotating shaft is coaxially fixed to the output end of the storage motor, and the rotating shaft rotates through the charging pile body and extends into the charging pile body, two limiting rollers are configured, symmetrically fixed on the rotating shaft, and there is a gap between the two limiting rollers, the cable fixing column is vertically fixed on the outer wall of the rotating shaft, and is located in the gap between the two limiting rollers, the cable fixing column is fixedly connected to the cable, and the cable resetting mechanism is arranged in the left side wall of the charging pile body.

Description

Technical Field

[0001] The present invention relates to the technical field of charging piles, and in particular to a charging pile with an automatic cable recovery and storage structure. Background Art

[0002] With the rapid development of the electric vehicle industry, the market demand for electric vehicle charging pile cables has also increased sharply. The production capacity and quality of the entire charging pile cable industry have attracted much attention from the market. The reliability and service life of the cables have an important impact on the development of the electric vehicle industry.

[0003] However, charging pile cables are usually long and need to be bent and moved frequently during use to connect the charging pile and the electric vehicle. The cable's own weight and the stress during bending may cause the internal conductors of the cable to move relative to each other, thus forming local kinks and generating torsional forces, which may eventually lead to cable breakage.

[0004] Therefore, it is necessary to invent a charging pile with an automatic cable recovery and storage structure to solve the above problems. Summary of the invention

[0005] In view of the above problems, the present invention provides a charging pile with an automatic cable recovery and storage structure, which solves the problem of cable breakage caused by the torsional force generated by the cable.

[0006] The technical solution adopted by the present invention is: it includes a charging pile body, and also includes a storage motor, a rotating shaft, a limiting roller, a cable fixing column and a cable reset mechanism; a built-in groove is opened in the rear side wall of the charging pile body, the storage motor is fixed in the built-in groove, the rotating shaft is coaxially fixed to the output end of the storage motor, and the rotating shaft rotates through the charging pile body and extends into the charging pile body, the limiting roller is configured with two, symmetrically fixed on the rotating shaft, and there is a gap between the two limiting rollers, the cable fixing column is vertically fixed on the outer wall of the rotating shaft, and is located in the gap between the two limiting rollers, the cable fixing column is fixedly connected to the cable, and the cable reset mechanism is arranged in the left side wall of the charging pile body.

[0007] Further, as a preference, the cable resetting mechanism includes a guide cylinder, an X-ray imager, a front end clamping assembly, a rear end clamping assembly and a linkage assembly; the guide cylinder is fixedly passed through the left side wall of the charging pile body, two X-ray imagers are symmetrically arranged, respectively installed on both sides of the inner wall of the guide cylinder, and the X-ray imager is electrically connected to an external control terminal, the front end clamping assembly is arranged at the left end of the inner wall of the guide cylinder, the rear end clamping assembly is arranged at the right end of the inner wall of the guide cylinder, and the linkage assembly is arranged between the charging pile body and the front end clamping assembly and the rear end clamping assembly.

[0008] Further, as a preference, the front-end clamping assembly and the rear-end clamping assembly both include a fixed cylinder, an inner cylinder, a gear ring, a sliding column, a return spring, a triangular prism and an arc-shaped clamping ring; the fixed cylinders are symmetrically arranged with two, both are fixed on the inner wall of the guide cylinder, there is a gap between the two fixed cylinders, an annular groove is opened inwardly on one side of the two fixed cylinders close to each other, the inner cylinder is rotatably arranged in the two annular grooves, a T-shaped groove is also opened inwardly on one side of the two fixed cylinders close to each other, T-shaped rings are connected to both sides of the gear ring, and the two T-rings are rotatably arranged on the two T-shaped The toothed ring is rotatably arranged in the gap between the two fixed cylinders, a plurality of rectangular through holes are opened along the radial circumference in the central part of the inner cylinder, a plurality of sliding columns are arranged on the circumference of the sliding column, and are respectively slidably arranged in the rectangular through holes, a rectangular groove is also connected on the inner cylinder in the middle of the rectangular through hole, a rectangular block is connected to the middle of the sliding column, the return spring is connected between the rectangular block and the inner wall of the rectangular groove, a plurality of triangular prisms are arranged, one of which has a flat end fixed on the sliding column away from one end, and a plurality of arc-shaped clamping rings are arranged, which are fixed on the sliding column close to one end.

[0009] Further, as a preference, the linkage assembly includes a drive motor, a bevel gear set, a guide rod and a spur gear; a placement groove and a gear groove are opened in the left side wall of the charging pile body, the drive motor is fixed on the inner wall of the placement groove, and the drive motor is electrically connected to the external control end, the bevel gear set is arranged in the gear groove, and it has two output ends, and the two output ends are 180° to each other, the input end of the bevel gear set is fixed to the output end of the drive motor, the guide rods are symmetrically arranged with two, one end of the two guide rods are respectively fixed to the two output ends of the bevel gear set, and the other ends of the two guide rods rotate to pass through the left side wall of the charging pile body, the spur gears are symmetrically arranged with two, which are respectively fixed at one end of the two guide rods away from each other, and the spur gears are meshed with the gear ring.

[0010] Further, as a preference, a plurality of groups of sector-shaped columns are fixed on the circumference of the inner wall of the gear ring in the front end clamping assembly, each group is provided with two, and the two sector-shaped columns are located on both sides above a triangular prism.

[0011] Further, preferably, a plurality of arc-shaped platforms are fixed on the circumference of the inner wall of the gear ring in the rear end clamping assembly, the cross section of which is configured as a semi-fan shape, and two adjacent arc-shaped platforms are located on both sides above the triangular prism.

[0012] Furthermore, preferably, the arc-shaped clamping ring is provided with a plurality of major arc ball grooves on the circumference of one side away from the sliding column, balls are rolled in the major arc ball grooves, a plurality of elastic balls of different sizes are rolled between the balls and the major arc ball grooves, the elastic balls contain magnesium powder, and a plurality of through holes are provided on the outer surface of the elastic balls.

[0013] Advantages of the present invention: In the present invention, by driving the linkage assembly of the driving motor, the front clamping assembly can not only achieve circumferential twisting of the cable, but also fixation of the cable by the rear clamping assembly, thereby correcting local twisting of the cable and preventing cable breakage.

[0014] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0016] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 is a side cross-sectional view of the interior of the charging pile body of the present invention; Figure 3 It is a schematic diagram of the structure of the cable resetting mechanism of the present invention; Figure 4 is a front cross-sectional view of the front end clamping assembly of the present invention; Figure 5 is a side cross-sectional view of the front end clamping assembly of the present invention; Figure 6 is a side cross-sectional view of a rear end clamping assembly of the present invention; Figure 7 It is an enlarged view of point A of the present invention; Figure 8 It is a schematic diagram of the internal structure of the cable of the present invention.

[0017] Figure numerals: 1. Charging pile body; 2. Storage motor; 3. Rotating shaft; 4. Limiting roller; 5. Cable fixing column; 6. Cable reset mechanism; 7. Cable; 61. Guide cylinder; 62. X-ray imager; 63. Front clamping assembly; 64. Rear clamping assembly; 65. Linkage assembly; 81. Fixed cylinder; 82. Inner cylinder; 83. Gear ring; 84. Sliding column; 85. Reset spring; 86. Triangular prism; 87. Arc clamping ring; 651. Drive motor; 652. Bevel gear set; 653. Guide rod; 654. Straight gear; 90. Fan-shaped column; 91. Arc table; 871. Major arc ball groove; 872. Ball; 873. Elastic ball. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0019] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0020] refer to Figures 1 to 8 , a charging pile with an automatic cable recovery and storage structure, comprising a charging pile body 1, a storage motor 2, a rotating shaft 3, a limiting roller 4, a cable fixing column 5 and a cable reset mechanism 6; a built-in groove is opened in the rear side wall of the charging pile body 1, the storage motor 2 is fixed in the built-in groove, the rotating shaft 3 is coaxially fixed to the output end of the storage motor 2, and the rotating shaft 3 rotates through the charging pile body 1 and extends into the charging pile body 1, the limiting roller 4 is configured with two, symmetrically fixed on the rotating shaft 3, and there is a gap between the two limiting rollers 4, the cable fixing column 5 is vertically fixed on the outer wall of the rotating shaft 3, and is located in the gap between the two limiting rollers 4, the cable fixing column 5 is fixedly connected to the cable 7, and the cable reset mechanism 6 is arranged in the left side wall of the charging pile body 1.

[0021] Please note that Figure 1 to Figure 2 The external control end can control the storage motor 2 to drive the rotating shaft 3 and the two limiting rollers 4 to rotate, thereby realizing the cable storage action. Among them, the two limiting rollers 4 can make the cable 7 wind in one direction, avoiding misalignment between the cables and avoiding the generation of torsional force.

[0022] As a preferred embodiment, the cable resetting mechanism 6 includes a guide cylinder 61, an X-ray imager 62, a front end clamping assembly 63, a rear end clamping assembly 64 and a linkage assembly 65; the guide cylinder 61 is fixedly passed through the left side wall of the charging pile body 1, and two X-ray imagers 62 are symmetrically arranged, which are respectively installed on both sides of the inner wall of the guide cylinder 61, and the X-ray imager 62 is electrically connected to the external control end, the front end clamping assembly 63 is arranged at the left end of the inner wall of the guide cylinder 61, and the rear end clamping assembly 64 is arranged at the right end of the inner wall of the guide cylinder 61, and the linkage assembly 65 is arranged between the charging pile body 1 and the front end clamping assembly 63 and the rear end clamping assembly 64.

[0023] For explanation, see Figure 8 The X-ray imager 62 can penetrate the sheath of the cable 7 and image the internal conductor, thereby intuitively displaying the structure and layout of the wire. That is to say, during the storage process of the cable 7, the two X-ray imagers 62 can image the conductors at both ends of the cable 7. If the conductors on both sides are not on the same horizontal line, that is, the cable 7 is twisted, the front end clamping component 63 and the rear end clamping component 64, that is, the linkage component 65, are used to correct the twisting of this part of the cable 7 so that the conductors in this part are on the same horizontal line.

[0024] In addition, the front end clamping assembly 63 can perform a twisting action on the cable 7 , and the rear end clamping assembly 64 keeps the end of the cable 7 fixed during the twisting action of the front end clamping assembly 63 .

[0025] As a preferred embodiment, the front end clamping assembly 63 and the rear end clamping assembly 64 both include a fixed cylinder 81, an inner cylinder 82, a gear ring 83, a sliding column 84, a return spring 85, a triangular prism 86 and an arc-shaped clamping ring 87; the fixed cylinders 81 are symmetrically arranged with two, both are fixed on the inner wall of the guide cylinder 61, there is a gap between the two fixed cylinders 81, an annular groove is opened inwardly on one side of the two fixed cylinders 81 close to each other, the inner cylinder 82 is rotatably arranged in the two annular grooves, a T-shaped groove is also opened inwardly on one side of the two fixed cylinders 81 close to each other, T-shaped rings are connected on both sides of the gear ring 83, and the two T-rings are rotatably arranged on the two The gear ring 83 is rotatably arranged in the gap between the two fixed cylinders 81, and a plurality of rectangular through holes are opened along the radial circumference in the central part of the inner cylinder 82. The sliding column 84 is arranged with a plurality of circles, which are respectively slidably arranged in the rectangular through holes. A rectangular groove is also connected to the inner cylinder 82 in the middle of the rectangular through hole. A rectangular block is connected to the middle of the sliding column 84, and the return spring 85 is connected between the rectangular block and the inner wall of the rectangular groove. A plurality of triangular prisms 86 are arranged, and one flat end of the triangular prisms 86 is fixed on the sliding column 84 at one end away from each other. A plurality of arc-shaped clamping rings 87 are arranged, which are fixed on the sliding column 84 at one end close to each other.

[0026] As a preferred embodiment, the linkage assembly 65 includes a driving motor 651, a bevel gear set 652, a guide rod 653 and a spur gear 654; a placement groove and a gear groove are opened in the left side wall of the charging pile body 1, the driving motor 651 is fixed on the inner wall of the placement groove, and the driving motor 651 is electrically connected to the external control end, the bevel gear set 652 is arranged in the gear groove, and it has two output ends, and the two output ends are 180° to each other, the input end of the bevel gear set 652 is fixed to the output end of the driving motor 651, the guide rod 653 is symmetrically arranged with two, one end of the two guide rods 653 is respectively fixed to the two output ends of the bevel gear set 652, and the other end of the two guide rods 653 rotates through the left side wall of the charging pile body 1, the spur gear 654 is symmetrically arranged with two, which are respectively fixed on the ends of the two guide rods 653 away from each other, and the spur gear 654 is meshed with the gear ring 83.

[0027] As a preferred embodiment, a plurality of groups of sector columns 90 are fixed on the circumference of the inner wall of the gear ring 83 in the front end clamping assembly 63 , with two sectors in each group. The two sector columns 90 are located on both sides above a triangular prism 86 .

[0028] For explanation, see Figures 3 to 5 In the front end clamping assembly 63, when the driving motor 651 is started, the transmission of the bevel gear set 652 causes the guide rod 653 to rotate, thereby driving the spur gear 654 to rotate, and the spur gear 654 drives the gear ring 83 to rotate through meshing, and the gear ring 83 drives the sector column 90 to rotate. When the inclined surface of the sector column 90 rotates to mesh with the inclined surface of the triangular prism 86, the component force of the circumferential tangent of the sector column 90 will push the triangular prism 86 to move radially inward, so that the sliding column 84 drives the arc clamping ring 87 to fit closely to the cable 7, completing the positioning of the cable 7. Thereafter, since the arc clamping ring 87 cannot continue to move inward, the sector column 90 will be relatively stationary with the triangular prism 86. That is to say, when the driving motor 651 is driven continuously, the sector column 90 will drive the triangular prism 86 to rotate synchronously, so that multiple arc clamping rings 87 can drive the cable 7 to twist circumferentially.

[0029] As a preferred embodiment, a plurality of arc-shaped platforms 91 are fixed on the circumference of the inner wall of the gear ring 83 in the rear end clamping assembly 64 , and the cross section thereof is configured as a semi-fan shape, and two adjacent arc-shaped platforms 91 are located on both sides above the triangular prism 86 .

[0030] For explanation, see Figure 3 and Figure 6In the rear end clamping assembly 64, when the driving motor 651 is started, the guide rod 653 is rotated through the transmission of the bevel gear set 652, thereby driving the spur gear 654 to rotate, and the spur gear 654 drives the gear ring 83 to rotate through meshing, and the gear ring 83 drives the arc table 91 to rotate. When the inclined surface of the arc table 91 rotates to mesh with the inclined surface of the triangular prism 86, the circumferential tangent force of the arc table 91 pushes the triangular prism 86 to move radially inward, thereby sliding. The moving column 84 drives the arc-shaped clamping ring 87 to be close to the cable 7, thereby completing the position limiting of the cable 7. The difference from the front-end clamping assembly 63 is that when the arc-shaped clamping ring 87 completes the position limiting of the cable 7, the inner wall of the arc-shaped table 91 just moves to contact with the tip of the triangular prism 86. That is to say, when the driving motor 651 is continuously driven, the arc-shaped table 91 will rotate, that is, the top of the triangular prism 86 slides on the inner wall of the arc-shaped table 91, and the arc-shaped clamping ring 87 remains stationary.

[0031] Therefore, by driving the driving motor 651, the front end clamping assembly 63 can perform circumferential twisting on the cable 7, and the rear end clamping assembly 64 can fix the cable 7, thereby performing local twisting correction on the cable 7 and preventing the cable 7 from breaking.

[0032] In addition, it is also necessary to explain that after the twisting and straightening of the local cable 7 is completed, the drive motor 651 will drive in the reverse direction so that each component returns to its initial state. Under the action of the reset force of the reset spring 85, multiple arc-shaped clamping rings 87 are detached from the cable 7, that is, the limit on the cable 7 is released, so that the cable can be stored easily.

[0033] As a preferred embodiment, the arc-shaped clamping ring 87 is provided with a plurality of major arc ball grooves 871 on the circumference of one side away from the sliding column 84, and a ball 872 is rolled in the major arc ball groove 871. A plurality of elastic balls 873 of different sizes are rolled between the ball 872 and the major arc ball groove 871, and the elastic ball 873 contains magnesium powder, and a plurality of through holes are provided on the outer surface of the elastic ball 873.

[0034] That is, see Figure 7 When the sliding column 84 drives the arc clamping ring 87 to move toward the surface of the cable 7, the ball 872 will squeeze the elastic ball 873, causing the elastic ball 873 to deform. Due to the deformation of the elastic ball 873, a part of the area will expand, so that the through hole in this area will become larger, and the magnesium powder will be squeezed out through the enlarged through hole. The released magnesium powder will reach between the cable 7 and the arc clamping ring 87, thereby increasing the friction between the arc clamping ring 87 and the cable 7.

[0035] In addition, when the cable 7 is partially flattened by an external heavy object, the arc-shaped clamping ring 87 can gather the flat part of the cable 7 to achieve the purpose of correction.

[0036] Specifically, during implementation, when the cable 7 is stored, two X-ray imagers 62 are used to image the two ends of the conductor entering the guide tube 61. If the conductors at the two ends are on the same horizontal line, the external control end controls the storage motor 2 to drive the rotating shaft 3 to store the cable 7. If the conductors at the two ends are not on the same horizontal line, the X-ray imager 62 will transmit this signal to the external control end, and the external control end controls the drive motor 651 to start. Under the drive of the drive motor 651, the rear end clamping assembly 64 can fix the cable 7, and the front end clamping assembly 63 can drive the cable 7 to twist circumferentially, so that the cable 7 can be partially torsionally corrected, thereby preventing the cable 7 from breaking; when the local correction is completed, the external control end controls the drive motor 651 to drive in reverse to reset the components. Thereafter, the external control end controls the storage motor 2 to drive and store the cable 7. This cycle completes the correction and storage of the entire cable 7.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A charging pile with an automatic cable recovery and storage structure, comprising a charging pile body (1), characterized in that: It also includes a storage motor (2), a rotating shaft (3), a limiting roller (4), a cable fixing column (5) and a cable reset mechanism (6); a built-in groove is opened in the rear side wall of the charging pile body (1), the storage motor (2) is fixed in the built-in groove, the rotating shaft (3) is coaxially fixed to the output end of the storage motor (2), and the rotating shaft (3) rotates through the charging pile body (1) and extends into the charging pile body (1), two limiting rollers (4) are configured, symmetrically fixed on the rotating shaft (3), and there is a gap between the two limiting rollers (4), the cable fixing column (5) is vertically fixed on the outer wall of the rotating shaft (3), and is located in the gap between the two limiting rollers (4), the cable fixing column (5) is fixedly connected to the cable (7), and the cable reset mechanism (6) is arranged in the left side wall of the charging pile body (1).

2. The charging pile with an automatic cable recovery and storage structure according to claim 1, characterized in that: The cable resetting mechanism (6) comprises a guide cylinder (61), an X-ray imager (62), a front-end clamping assembly (63), a rear-end clamping assembly (64) and a linkage assembly (65); the guide cylinder (61) is fixedly passed through the left side wall of the charging pile body (1); two X-ray imagers (62) are symmetrically arranged and respectively mounted on both sides of the inner wall of the guide cylinder (61); and the X-ray imagers (62) are electrically connected to an external control terminal; the front-end clamping assembly (63) is arranged at the left end of the inner wall of the guide cylinder (61); the rear-end clamping assembly (64) is arranged at the right end of the inner wall of the guide cylinder (61); and the linkage assembly (65) is arranged between the charging pile body (1) and the front-end clamping assembly (63) and the rear-end clamping assembly (64).

3. The charging pile with an automatic cable recovery and storage structure according to claim 2, characterized in that: The front end clamping assembly (63) and the rear end clamping assembly (64) both comprise a fixed cylinder (81), an inner cylinder (82), a gear ring (83), a sliding column (84), a return spring (85), a triangular prism (86) and an arc-shaped clamping ring (87); two fixed cylinders (81) are symmetrically arranged and are both fixed on the inner wall of the guide cylinder (61); a gap exists between the two fixed cylinders (81); an annular groove is provided inwardly on one side of the two fixed cylinders (81) close to each other; the inner cylinder (82) is rotatably arranged in the two annular grooves; a T-shaped groove is also provided inwardly on one side of the two fixed cylinders (81) close to each other; T-shaped rings are connected to both sides of the gear ring (83); the two T-shaped rings are rotatably arranged on the two sides. The gear ring (83) is rotatably arranged in the gap between the two fixed cylinders (81); a plurality of rectangular through holes are opened along the radial circumference at the central portion of the inner cylinder (82); a plurality of sliding columns (84) are arranged circumferentially and are respectively slidably arranged in the rectangular through holes; a rectangular groove is also opened on the inner cylinder (82) in the middle of the rectangular through hole; a rectangular block is connected to the middle of the sliding column (84); the return spring (85) is connected between the rectangular block and the inner wall of the rectangular groove; a plurality of triangular prisms (86) are arranged, one of which has a flat end fixed to one end of the sliding column (84) away from each other; a plurality of arc-shaped clamping rings (87) are arranged, which are fixed to one end of the sliding column (84) close to each other.

4. The charging pile with an automatic cable recovery and storage structure according to claim 3, characterized in that: The linkage assembly (65) comprises a drive motor (651), a bevel gear set (652), a guide rod (653) and a spur gear (654); a placement groove and a gear groove are provided in the left side wall of the charging pile body (1); the drive motor (651) is fixed on the inner wall of the placement groove, and the drive motor (651) is electrically connected to an external control end; the bevel gear set (652) is arranged in the gear groove and has two output ends, and the two output ends are 180 degrees to each other; the bevel gear set (652) ) is fixed to the output end of the driving motor (651), two guide rods (653) are symmetrically arranged, one end of the two guide rods (653) is respectively fixed to the two output ends of the bevel gear set (652), and the other ends of the two guide rods (653) rotate and penetrate the left side wall of the charging pile body (1), and two spur gears (654) are symmetrically arranged and are respectively fixed to the ends of the two guide rods (653) that are away from each other, and the spur gears (654) are meshed with the gear ring (83).

5. The charging pile with an automatic cable recovery and storage structure according to claim 4, characterized in that: A plurality of groups of sector-shaped columns (90) are fixed on the circumference of the inner wall of the toothed ring (83) in the front end clamping assembly (63), with each group having two sector-shaped columns. The two sector-shaped columns (90) are located on both sides above a triangular prism (86).

6. The charging pile with an automatic cable recovery and storage structure according to claim 4, characterized in that: A plurality of arc-shaped platforms (91) are fixed on the circumference of the inner wall of the toothed ring (83) in the rear end clamping assembly (64), the cross section of which is configured as a semi-sector shape, and two adjacent arc-shaped platforms (91) are located on both sides above the triangular prism (86).

7. The charging pile with an automatic cable recovery and storage structure according to claim 3, characterized in that: A plurality of major arc ball grooves (871) are provided on the circumference of one side of the arc clamping ring (87) away from the sliding column (84), a ball (872) is rotatably arranged in the major arc ball groove (871), a plurality of elastic balls (873) of different sizes are rotatably arranged between the ball (872) and the major arc ball groove (871), the elastic balls (873) contain magnesium powder, and a plurality of through holes are provided on the outer surface of the elastic balls (873).

Images