Graphite refining and screening equipment
By designing shaking and limiting components, the problem of easy clogging of the screening mesh is solved, achieving efficient graphite screening and convenient cleaning operations, thus improving screening efficiency and convenience.
Patent Information
- Application Number
- CN202423109193.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-17
- Publication Date
- 2025-11-25
- Estimated Expiration
- 2034-12-17
AI Technical Summary
In existing graphite screening devices, the screening mesh is easily clogged by large graphite particles, resulting in low screening efficiency and requiring manual cleaning.
A shaking component is used to drive the arc-shaped screening frame to shake, preventing large graphite particles from clogging it. Combined with a limiting component, it is easy to clean the screening frame. The reciprocating shaking and fixing of the screening frame is achieved by a motor-driven rotating shaft and gear meshing.
It effectively prevents the screening screen from clogging, improves the efficiency of graphite screening, simplifies the cleaning process of the screening frame, and reduces manual intervention.
Smart Images
Figure CN223587657U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to graphite screening technical field especially relates to a graphite refining screening equipment. BACKGROUND
[0002] Graphite is a carbon allotrope with unique properties. Its characteristics include dark gray scaly solid, soft and smooth, good electrical conductivity, etc. Due to its excellent physical and chemical properties, graphite is widely used in many fields. The performance and quality of graphite are closely related to its purity. In order to improve the performance of graphite, it needs to be refined and screened. Screening can effectively separate impurities in graphite, significantly reduce impurity content, such as reducing ash content of products from 0.5-0.8% to about 0.3%, thereby improving the purity of graphite. By screening, the particle size and distribution of graphite are controlled to ensure the consistency and reliability of the product. It is also crucial for the dimensional accuracy and sealing performance of graphite products. In summary, the screening of refined graphite is an indispensable part of the graphite processing process, which is of great significance to improve the quality and performance of graphite products.
[0003] However, in the prior art, in order to improve the quality of graphite, the refined graphite needs to be screened after being ground. The screening net inside the existing graphite screening device is usually of fixed structure. When screening graphite, the graphite accumulates on the surface of the stationary screening net. Some large particles of graphite may block the screening net, which needs to be manually cleaned, thereby greatly reducing the efficiency of graphite screening.
[0004] Therefore, a graphite refining screening equipment is proposed to solve the above problems. CONTENT OF THE UTILITY MODEL
[0005] The utility model aims at solving the problems in the prior art.
[0006] In order to achieve the above purpose, the utility model adopts the following technical scheme: a graphite refining screening equipment, comprising: a screening box, a plurality of supporting legs are fixedly installed on the bottom surface of the screening box, a discharge port is connected through the center of the bottom surface of the screening box, a feeding port is connected through the top surface of the screening box, a control terminal is fixedly arranged on one side surface of the screening box, a through slot is arranged on the other side surface of the screening box, a box door is connected through a hinge on one end of the other side surface of the screening box, a sealing strip is fixedly installed on one side surface of the box door, an arc plate is fixedly installed on one side surface of the box door, a shaking assembly is arranged between the inner walls of the two sides of the screening box, a limiting assembly is arranged on one side surface of the shaking assembly, the shaking assembly comprises a rotating rod, the rotating rod is connected through a bearing on one side inner wall surface of the screening box, the other end of the rotating rod is connected through a bearing and penetrates the other side inner wall surface of the screening box.
[0007] As a preferred implementation, the outer wall surface of the rotating rod is fixedly sleeved with a U-shaped support plate, the U-shaped support plate is located inside the screening box, long grooves are formed in the inner wall surfaces of the two sides of the U-shaped support plate, U-shaped plates are movably installed in the two long grooves, arc-shaped screening frames are fixedly installed on the bottom surfaces of the two U-shaped plates, and arc-shaped grooves are formed in the two side surfaces of the arc-shaped screening frame.
[0008] As a preferred implementation, one end of the outer wall surface of the rotating rod is fixedly sleeved with a gear, the gear is located outside the screening box, two U-shaped rods are fixedly installed on one side surface of the screening box, a back-shaped plate is movably sleeved on the surfaces of the two U-shaped rods, a first rack is fixedly installed on the top surface of the back-shaped plate, the first rack and the gear are intermeshed, and second racks are fixedly installed on the inner wall surfaces of the upper and lower sides of the back-shaped plate.
[0009] As a preferred implementation, an L-shaped plate is fixedly installed on one side surface of the screening box, a rotating shaft is connected between the inner wall surface of one side of the L-shaped plate and the side surface of the screening box through a bearing, a motor is fixedly installed on one side surface of the L-shaped plate, the output end of the motor movably penetrates through the side surface of the L-shaped plate and is fixedly connected with one end of the rotating shaft, a half gear is fixedly sleeved on the outer wall surface of the rotating shaft, and the half gear and the two second racks are intermeshed.
[0010] As a preferred implementation, the limiting assembly comprises two cross grooves and two limiting holes, the two limiting holes are formed at one end of the inner wall surface of one side of the two long grooves, the two cross grooves are formed on the side surface of the two U-shaped plates, cross plates are movably connected between the inner walls of the two cross grooves, limiting rods are fixedly installed on the side surfaces of the two cross plates, and the two limiting rods are correspondingly inserted into the two limiting holes.
[0011] As a preferred implementation, springs are fixedly installed between the two side inner wall surfaces of the two cross grooves and the two side surfaces of the two cross plates.
[0012] As a preferred implementation, two supporting rods are fixedly installed on the side surface of each of the two U-shaped plates, limiting plates are fixedly installed on the end surfaces of the supporting rods, every two of the supporting rods form a group, movable plates are movably sleeved on the surfaces of the two groups of supporting rods, hinged plates are hinged to the side surfaces of the two movable plates, the other ends of the two hinged plates are hingedly connected with the other side surfaces of the two cross plates, push plates are fixedly installed on the other side surfaces of the two movable plates, and the end surfaces of the two push plates are movably attached to the end surfaces of the arc-shaped plates.
[0013] Compared with the prior art, the utility model has the advantages and positive effects that
[0014] 1、The utility model discloses, motor operation drives the rotation of the pivot, and the pivot rotation drives the rotation of the half gear, and the half gear and two second racks are all corresponding meshing, and the convex tooth on the half gear surface is sequentially meshed with two second racks, and the half gear rotation drives the back type board to reciprocatingly move on the surface of two U-shaped rods,
[0015] The back type board reciprocatingly moving drives the first rack to reciprocatingly move, and the first rack and the gear are meshed with each other, thereby making the rotating rod reciprocatingly rotate, and the rotating rod rotation drives the U-shaped support plate to rotate with the rotating rod as the center shaft, and the U-shaped support plate rotation drives the arc-shaped screening frame to reciprocatingly shake with the rotating rod as the center shaft, and the graphite particles shake in the inside of the arc-shaped screening frame, preventing the larger graphite particles from blocking the arc-shaped screening frame, and the larger graphite particles are still in the inside of the arc-shaped screening frame, and the graphite particles screened through the arc-shaped screening frame are discharged into the inside of the collecting box through the discharge port.
[0016] Through the cooperation of the above structure, the half gear cooperates with two second racks to drive the arc-shaped screening frame to reciprocatingly rotate, thereby driving the graphite particles in the inside of the arc-shaped screening frame to shake, avoiding that the larger graphite particles are accumulated on the surface of the arc-shaped screening frame and block the arc-shaped screening frame, and affecting the efficiency of graphite particle screening.
[0017] 2、The utility model discloses, when the door is closed, the arc-shaped plate will push two push plates, and the two push plates move drive two movable plates to move on the surface of the corresponding support rod, and the two movable plates move drive two hinged plates to move, and the two hinged plates move drive two cross plates to move in the inside of two cross grooves, and the two cross plates move can extrude or stretch multiple springs, and simultaneously, the two cross plates move drive two limiting rods to move, and the two limiting rods move make them be inserted in the inside of two limiting holes, thereby limiting two U-shaped plates in two long grooves, so that the arc-shaped screening frame is fixed in the inside of the screening box;
[0018] When the door is opened, the arc-shaped plate moves and removes the push to the two push plates, so that the two push plates lose the limitation, and the resilience of multiple springs makes the two cross plates reset, and the two limiting rods move make them move out from the inside of two limiting holes, thereby making the two U-shaped plates lose the limitation in the inside of two long grooves, at this time, the arc-shaped screening frame is taken out from the inside of the screening box, and the graphite particles in the inside of the arc-shaped screening frame are cleaned;
[0019] Through the cooperation of the above structure, the arc-shaped screening frame can be limited in the inside of the screening box when the door is closed, and the limitation of the arc-shaped screening frame can be removed when the door is opened, so that the arc-shaped screening frame is conveniently cleaned. DRAWINGS
[0020] Figure 1The utility model provides a kind of graphite refining screening equipment's three-dimensional structure schematic view is provided;
[0021] Figure 2 The utility model provides a kind of graphite refining screening equipment's sectional structure schematic view is provided;
[0022] Figure 3 The utility model provides a kind of graphite refining screening equipment's right view structure schematic view is provided;
[0023] Figure 4 The utility model provides a kind of graphite refining screening equipment screening net's structure schematic view is provided;
[0024] Figure 5 The utility model provides a kind of graphite refining screening equipment shaking subassembly's structure schematic view is provided;
[0025] Figure 6 The utility model provides a kind of graphite refining screening equipment box door's structure schematic view is provided;
[0026] Figure 7 The utility model provides a kind of graphite refining screening equipment Figure 3 The structure schematic view of A in the utility model is provided;
[0027] Figure 8 The structure schematic view of B in the utility model is provided; Figure 4 The structure schematic view of C in the utility model is provided.
[0028] Figure 9 The structure schematic view of C in the utility model is provided. Figure 5 The structure schematic view of C in the utility model is provided.
[0029] Legend:
[0030] 1, screening box;2, support leg;3, discharge port;4, feeding port;5, control terminal;6, through slot;7, box door;701, sealing strip;702, arc plate;8, shaking subassembly;801, rotating rod;802, U-shaped support plate;803, long groove;804, U-shaped plate;805, arc-shaped screening frame;806, gear;807, U-shaped rod;808, back-shaped plate;809, first rack;810, second rack;811, L-shaped plate;812, rotating shaft;813, motor;814, half gear;9, limiting component;901, cross slot;902, limiting hole;903, cross plate;904, limiting rod;905, spring;906, support rod;907, limiting plate;908, movable plate;909, hinged plate;910, push plate. Specific implementation
[0031] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described, obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.
[0032] Please refer to Figures 1-9 The present application provides a technical scheme: a graphite refining and screening device, comprising: a screening box 1, a plurality of supporting legs 2 are fixedly installed on the bottom surface of the screening box 1, a discharge port 3 is connected through the center of the bottom surface of the screening box 1, a feeding port 4 is connected through the top surface of the screening box 1, a control terminal 5 is fixedly arranged on one side surface of the screening box 1, a through slot 6 is arranged on the other side surface of the screening box 1, a box door 7 is connected to one end of the other side surface of the screening box 1 through a hinge, a sealing strip 701 is fixedly installed on one side surface of the box door 7, an arc-shaped plate 702 is fixedly installed on one side surface of the box door 7, a shaking assembly 8 is arranged between the two side inner walls of the screening box 1, a limiting assembly 9 is arranged on one side surface of the shaking assembly 8, the shaking assembly 8 comprises a rotating rod 801, the rotating rod 801 is connected to one side inner wall surface of the screening box 1 through a bearing, and the other end of the rotating rod 801 penetrates through the other side inner wall surface of the screening box 1 through a bearing.
[0033] Specifically, the control terminal 5 plays a role in controlling the operation of the motor 813, the sealing strip 701 is fixedly installed on one side surface of the box door 7, and when the box door 7 is closed, the sealing gasket can be clamped on the inner wall surface of the through slot 6 to achieve sealing and friction to prevent the box door 7 from being easily opened and closed.
[0034] In one embodiment, a U-shaped supporting plate 802 is fixedly sleeved on the outer wall surface of the rotating rod 801, the U-shaped supporting plate 802 is located in the interior of the screening box 1, long grooves 803 are arranged on the two side inner wall surfaces of the U-shaped supporting plate 802, U-shaped plates 804 are movably installed in the two long grooves 803, arc-shaped screening frames 805 are fixedly installed on the bottom surfaces of the two U-shaped plates 804, and arc-shaped grooves are arranged on the two side surfaces of the arc-shaped screening frames 805.
[0035] Specifically, the two long grooves 803 play a role in movably installing the two U-shaped plates 804, the arc-shaped screening frames 805 play a role in screening graphite particles, and arc-shaped grooves are arranged on the two side surfaces of the arc-shaped screening frames 805, which are not marked in the figure, and are matched with the through slot 6, so that the arc-shaped screening frames 805 cannot be installed in the interior of the screening box 1.
[0036] In one embodiment, a gear 806 is fixedly sleeved on one end of the outer wall surface of the rotating rod 801. The gear 806 is located on the outside of the screening box 1. Two U-shaped rods 807 are fixedly installed on one side surface of the screening box 1. A return plate 808 is movably sleeved on the surface of the two U-shaped rods 807. A first rack 809 is fixedly installed on the top surface of the return plate 808. The first rack 809 meshes with the gear 806. A second rack 810 is fixedly installed on the inner wall surfaces of both the upper and lower sides of the return plate 808.
[0037] Specifically: when the return plate 808 moves to the extreme ends of the two U-shaped rods 807, the first rack 809 is always meshed with the gear 806.
[0038] In one embodiment, an L-shaped plate 811 is fixedly installed on one side surface of the screening box 1. A rotating shaft 812 is connected between the inner wall surface of one side of the L-shaped plate 811 and the one side surface of the screening box 1 via a bearing. A motor 813 is fixedly installed on one side surface of the L-shaped plate 811. The output end of the motor 813 movably passes through one side surface of the L-shaped plate 811 and is fixedly connected to one end of the rotating shaft 812. A half gear 814 is fixedly sleeved on the outer wall surface of the rotating shaft 812. The half gear 814 meshes with both second racks 810.
[0039] Specifically: the motor 813 drives the rotating shaft 812 to rotate. When the half gear 814 rotates, when the convex tooth at one end of its surface disengages from one of the second racks 810, the convex tooth at the other end simultaneously meshes with the other second rack 810, thereby causing the return plate 808 to reciprocate on the surfaces of the two U-shaped rods 807. When the return plate 808 reciprocates to the limit position, the gear 806 will not disengage from the first rack 809.
[0040] In one embodiment, the limiting component 9 includes two cross grooves 901 and two limiting holes 902. The two limiting holes 902 are respectively opened at one end of the inner wall surface of the two long grooves 803. The two cross grooves 901 are respectively opened on one side surface of the two U-shaped plates 804. A cross plate 903 is movably connected between the inner walls of the two cross grooves 901. A limiting rod 904 is fixedly installed on one side surface of the two cross plates 903. The two limiting rods 904 are respectively inserted into the inside of the two limiting holes 902.
[0041] Specifically: the limiting rod 904 can be inserted into the limiting hole 902 to restrict the two U-shaped plates 804 inside the two long slots 803.
[0042] In one embodiment, springs 905 are fixedly installed between the inner wall surfaces on both sides of the two cross grooves 901 and the two side surfaces of the two cross plates 903.
[0043] Specifically, the plurality of springs 905 limit the positions of the two cross plates 903 inside the two cross grooves 901.
[0044] In one embodiment, the side surfaces of the two U-shaped plates 804 are each fixedly installed with two support rods 906, the end surfaces of the plurality of support rods 906 are each fixedly installed with a limiting plate 907, every two of the plurality of support rods 906 form a group, the surfaces of the two groups of support rods 906 are each movably sleeved with a movable plate 908, the side surfaces of the two movable plates 908 are each hingedly connected with a hinge plate 909, the other ends of the two hinge plates 909 are hingedly connected with the other side surfaces of the two cross plates 903, the other side surfaces of the two movable plates 908 are each fixedly installed with a push plate 910, and the surfaces of one ends of the two push plates 910 are each movably attached to the end surfaces of the arc-shaped plate 702.
[0045] Specifically, the hinge plates 909 drive the two cross plates 903 to move inside the two cross grooves 901, the arc-shaped plate 702 is correspondingly arranged at the opposite positions of the two push plates 910, the top surfaces of the two ends of the arc-shaped plate 702 movably attach to the top inner wall surfaces of the through groove 6, and when the box door 7 is closed, the side surface of the arc-shaped plate 702 extending is flush with the side inner cavity surface of the screening box 1, when the box door 7 is closed, the arc-shaped plate 702 pushes the two push plates 910 to move, and when the two push plates 910 rotate, they always movably attach to the side surface of the arc-shaped plate 702 and the side inner wall surface of the screening box 1.
[0046] Working principle:
[0047] When the ground and refined graphite is screened, a collecting box is placed below the discharge port 3 in advance, an appropriate amount of graphite particles is added through the feeding port 4, the graphite particles fall on the surface of the arc-shaped screening frame 805, then the control terminal 5 is operated to run the motor 813, the motor 813 is driven to rotate the rotating shaft 812, the rotating shaft 812 is driven to rotate the half gear 814, the half gear 814 and the two second gear racks 810 are correspondingly engaged, the teeth on the surface of the half gear 814 are sequentially engaged with the two second gear racks 810, and the half gear 814 is rotated to drive the back-shaped plate 808 to reciprocate on the surfaces of the two U-shaped rods.
[0048] The reciprocating movement of the back-shaped plate 808 drives the reciprocating movement of the first rack 809, and the first rack 809 and the gear 806 are in meshing relationship, so that the rotating rod 801 rotates reciprocatingly, the rotating rod 801 drives the U-shaped support plate 802 to rotate around the rotating rod 801 as the center axis, the U-shaped support plate 802 drives the two U-shaped plates 804 to rotate around the rotating rod 801 as the center axis, and then the arc-shaped screening frame 805 reciprocates around the rotating rod 801 as the center axis. Since the arc-shaped screening frame 805 reciprocates, the graphite particles in the arc-shaped screening frame 805 are shaken, so that the graphite particles are prevented from being blocked in the arc-shaped screening frame 805, and the larger graphite particles are still in the arc-shaped screening frame 805. The graphite particles screened out of the arc-shaped screening frame 805 are discharged into the collecting box through the discharge port 3.
[0049] Through the cooperation of the above structure, the half gear 814 drives the arc-shaped screening frame 805 to rotate reciprocatingly through the two second racks 810, so that the graphite particles in the arc-shaped screening frame 805 are shaken, and the larger graphite particles are prevented from being accumulated on the surface of the arc-shaped screening frame 805 and blocking the arc-shaped screening frame 805, thereby affecting the screening efficiency of the graphite particles.
[0050] When the graphite particles are completely screened, some larger graphite particles are accumulated in the arc-shaped screening frame 805. At this time, the box door 7 is opened, and the movement of the box door 7 drives the movement of the arc-shaped plate 702. Since the arc-shaped plate 702 pushes against the two push plates 910 when the box door 7 is closed, the movement of the two push plates 910 drives the movement of the two movable plates 908 on the surface of the corresponding support rods 906, the movement of the two movable plates 908 drives the movement of the two hinged plates 909, the movement of the two hinged plates 909 drives the movement of the two cross plates 903 in the two cross grooves 901, and the movement of the two cross plates 903 squeezes or stretches the plurality of springs 905, so that the plurality of springs 905 are forced to compress or stretch. At the same time, the movement of the two cross plates 903 drives the movement of the two limiting rods 904, and the movement of the two limiting rods 904 makes the two limiting rods 904 inserted into the two limiting holes 902, so as to limit the two U-shaped plates 804 in the two long grooves 803, thereby fixing the arc-shaped screening frame 805 in the screening box 1.
[0051] When the box door 7 is opened, the movement of the arc-shaped plate 702 removes the pushing of the two push plates 910, so that the two push plates 910 lose the limitation. The resilience of the plurality of springs 905 makes the two cross plates 903 reset, the reset of the two cross plates 903 drives the movement of the two limiting rods 904, and the movement of the two limiting rods 904 makes the two limiting rods 904 move out of the two limiting holes 902, so that the two U-shaped plates 804 lose the limitation in the two long grooves 803. At this time, the arc-shaped screening frame 805 is taken out of the screening box 1, and the graphite particles in the arc-shaped screening frame 805 are cleaned.
[0052] Through cooperation of the above structure, the arc-shaped screening frame 805 can be limited inside the screening box 1 when the box door 7 is closed, and the limitation of the arc-shaped screening frame 805 can be released when the box door 7 is opened, so that the arc-shaped screening frame 805 is conveniently cleaned.
[0053] The above is only a preferred embodiment of the present application, and is not intended to limit the present application in other forms. Any skilled person in the art can modify or change the above disclosed technical content to equivalent embodiments applied to other fields, but any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application without departing from the technical scheme of the present application still falls within the protection scope of the present application.
Claims
1. A graphite refining and screening device, characterized in that, include: A screening box (1) has multiple support legs (2) fixedly installed on its bottom surface. A discharge port (3) is connected through the center of the bottom surface of the screening box (1). A feeding port (4) is connected through the top surface of the screening box (1). A control terminal (5) is fixedly installed on one side surface of the screening box (1). A through groove (6) is opened on the other side surface of the screening box (1). A door (7) is connected to one end of the other side surface of the screening box (1) via a hinge. One side surface of the door (7) A sealing strip (701) is fixedly installed on the surface of the box door (7). An arc plate (702) is fixedly installed on one side surface of the box door (7). A shaking assembly (8) is provided between the inner walls of the two sides of the screening box (1). A limiting assembly (9) is provided on one side surface of the shaking assembly (8). The shaking assembly (8) includes a rotating rod (801). The rotating rod (801) is connected to the inner wall surface of one side of the screening box (1) through a bearing. The other end of the rotating rod (801) passes through the inner wall surface of the other side of the screening box (1) through a bearing.
2. The graphite refining and screening equipment according to claim 1, characterized in that: A U-shaped support plate (802) is fixedly fitted on the outer wall surface of the rotating rod (801). The U-shaped support plate (802) is located inside the screening box (1). Long grooves (803) are opened on both inner wall surfaces of the U-shaped support plate (802). U-shaped plates (804) are movably installed inside the two long grooves (803). Arc-shaped screening frames (805) are fixedly installed on the bottom surface of the two U-shaped plates (804). Arc-shaped grooves are opened on both sides of the arc-shaped screening frames (805).
3. The graphite refining and screening device according to claim 1, characterized in that: A gear (806) is fixedly sleeved on one end of the outer wall surface of the rotating rod (801). The gear (806) is located on the outside of the screening box (1). Two U-shaped rods (807) are fixedly installed on one side surface of the screening box (1). A return plate (808) is movably sleeved on the surface of the two U-shaped rods (807). A first rack (809) is fixedly installed on the top surface of the return plate (808). The first rack (809) meshes with the gear (806). A second rack (810) is fixedly installed on the inner wall surfaces of the upper and lower sides of the return plate (808).
4. The graphite refining and screening device according to claim 1, characterized in that: An L-shaped plate (811) is fixedly installed on one side surface of the screening box (1). A rotating shaft (812) is connected between the inner wall surface of one side of the L-shaped plate (811) and the one side surface of the screening box (1) through a bearing. A motor (813) is fixedly installed on one side surface of the L-shaped plate (811). The output end of the motor (813) movably passes through one side surface of the L-shaped plate (811) and is fixedly connected to one end of the rotating shaft (812). A half gear (814) is fixedly sleeved on the outer wall surface of the rotating shaft (812). The half gear (814) meshes with two second racks (810).
5. The graphite refining and screening device according to claim 1, characterized in that: The limiting component (9) includes two cross grooves (901) and two limiting holes (902). The two limiting holes (902) are respectively opened at one end of the inner wall surface of one side of the two long grooves (803). The two cross grooves (901) are respectively opened on one side surface of the two U-shaped plates (804). Cross plates (903) are movably connected between the inner walls of the two cross grooves (901). Limiting rods (904) are fixedly installed on one side surface of the two cross plates (903). The two limiting rods (904) are respectively inserted into the inside of the two limiting holes (902).
6. The graphite refining and screening device according to claim 5, characterized in that: Springs (905) are fixedly installed between the inner wall surfaces on both sides of the two cross grooves (901) and the two side surfaces of the two cross plates (903).
7. The graphite refining and screening device according to claim 2, characterized in that: Two support rods (906) are fixedly installed on one side surface of each of the two U-shaped plates (804). Limiting plates (907) are fixedly installed on one end surface of each of the multiple support rods (906). Each pair of the multiple support rods (906) forms a group. Movable plates (908) are movably fitted onto the surfaces of the two groups of support rods (906). Hinged plates (909) are hinged to one side surface of each of the two movable plates (908). The other end of each of the two hinged plates (909) is hinged to the other side surface of each of the two cross plates (903). Push plates (910) are fixedly installed on the other side surface of each of the two movable plates (908). The surfaces of each of the two push plates (910) are movably fitted onto one end surface of the arc plate (702).