Coal injection device of decomposing furnace

Abstract

The utility model relates to the technical field of cement production, and discloses a decomposing furnace coal injection device which comprises a base, the top of the base is fixedly connected with a rotary kiln coal mill coal injection machine, the right end of the rotary kiln coal mill coal injection machine is fixedly connected with a control switch box, and the top end of the control switch box is fixedly connected with a discharging hopper. A recycling mechanism is fixedly connected to the interior of the discharging hopper, a dismounting and mounting mechanism is arranged in the recycling mechanism, the recycling mechanism comprises a supporting plate, the outer wall of the supporting plate is fixedly connected to the inner wall of the discharging hopper, and a scraping assembly is fixedly connected to the bottom end of the supporting plate. According to the pulverized coal recycling device, pulverized coal passes through the conveying pipe, the auger, the conveying pipe and the discharging port and then returns to the discharging hopper, and through the recycling process, originally abandoned coal briquettes are converted into usable pulverized coal again, so that the utilization rate of coal resources is increased.

Description

Technical Field

[0001] This utility model relates to the field of road maintenance technology, and in particular to an asphalt pavement maintenance paver. Background Technology

[0002] The cement decomposition furnace is a core thermal equipment in the cement production process, mainly used for the pre-decomposition and calcination of cement raw materials (mixtures of limestone, clay, etc.). It rapidly decomposes carbonates into calcium oxide at high temperatures (approximately 850-900℃), providing pretreatment for subsequent clinker sintering in the kiln. This equipment typically employs suspension preheating and swirl combustion technology, characterized by high thermal efficiency and a decomposition rate >90%. The pulverized coal injection unit, as a key subsystem of the decomposition furnace, is responsible for precisely injecting pulverized coal into the combustion zone within the furnace, providing a stable heat source for the decomposition reaction. Its performance directly affects fuel utilization and system operational stability.

[0003] A search revealed Chinese patent publication number CN222298464U, which discloses a pulverized coal injection device for a decomposition furnace. The device includes a rotary kiln coal mill pulverized coal injector, a vibrating motor, and a vibrating spring. A hopper is installed on one side of the upper surface of the rotary kiln coal mill pulverized coal injector. A feeding trough is formed on the upper surface of the hopper. A cylinder is placed on the upper surface of the cylinder, and a through hole is formed on its upper surface. A disc is fixed to the lower end of the inner wall of the through hole. A vibrating spring is fixed to the upper surface of the disc, and a second disc is fixed to the top of the vibrating spring. Vibrating motors are installed on both sides of the lower surface of the second disc. A circular hole is formed on the upper surface of the second disc, and a filter screen is fixed to the inner wall of the circular hole. This invention has the advantage of being able to screen pulverized coal, preventing the pulverized coal from containing coal lumps that could cause blockage of the pulverized coal injection pipe.

[0004] Although the aforementioned patent mentions that "a cylinder is placed on the upper surface of the hopper, a through hole is opened on the upper surface of the cylinder, a disc is fixed at the lower end of the inner wall of the through hole, a vibration spring is fixed on the upper surface of the disc, a disc is fixed at the top of the vibration spring, a vibration motor is installed on both sides of the lower surface of the disc, a circular hole is opened on the upper surface of the disc, and a filter screen is fixed on the inner wall of the circular hole. When it is necessary to inject pulverized coal into the cement decomposition furnace, the pulverized coal is poured into the through hole, the vibration motor is started, causing the vibration spring to deform elastically, the disc and the filter screen to vibrate, and the filter screen can screen the pulverized coal. The screened pulverized coal falls into the feed trough and then enters the rotary kiln coal mill pulverizer, achieving the effect of screening the pulverized coal and preventing the pulverized coal containing coal lumps from clogging the pulverized coal injection pipe," the coal lumps intercepted by the filter screen are simply piled up and discharged, which not only wastes fuel but also increases the cost of manual cleaning. Moreover, the screened coal lumps need to be processed by stopping the machine, which seriously affects the continuity of production. Therefore, in view of the above shortcomings, a pulverized coal injection device for a decomposition furnace is proposed to solve the above problems. Utility Model Content

[0005] To overcome the above shortcomings, this utility model provides a coal injection device for a decomposition furnace, which aims to improve the problems of low coal block processing efficiency and serious resource waste in some existing coal injection devices for decomposition furnaces.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A coal injection device for a decomposition furnace includes a base, a rotary kiln coal mill coal injector fixedly connected to the top of the base, a control switch box fixedly connected to the right end of the rotary kiln coal mill coal injector, a feeding hopper fixedly connected to the top of the control switch box, a recovery mechanism fixedly connected inside the feeding hopper, and a disassembly and assembly mechanism provided inside the recovery mechanism.

[0008] The recycling mechanism includes a support plate, the outer wall of which is fixedly connected to the inner wall of the hopper. A scraping component is fixedly connected to the bottom end of the support plate. A filter screen is installed on the inner wall of the hopper. A slag discharge port is opened on the right side of the hopper. A collection box is fixedly connected to the right side of the slag discharge port. A crushing box is fixedly connected to the bottom end of the collection box. A conveying pipe is fixedly connected to the bottom end of the crushing box. A conveying component is fixedly connected to the output end of the conveying pipe.

[0009] The above technical solution ensures stable operation under complex working conditions by supporting the entire device with a base. The rotary kiln coal mill pulverizer, as the core component, realizes the grinding and injection of pulverized coal. The control switch box integrates multiple functions, facilitating operation and monitoring of equipment status. The hopper provides an inlet for pulverized coal. The recovery mechanism effectively separates coal lumps from pulverized coal, realizing resource recycling. The disassembly and assembly mechanism facilitates subsequent component maintenance. All components are interconnected, constructing a complete and efficient pulverized coal injection device system for the decomposition furnace.

[0010] As a further description of the above technical solution:

[0011] The scraping assembly includes a motor, the top of which is fixedly connected to the bottom of the support plate, a rotating rod is fixedly connected to the output end of the motor, an insert rod is detachably connected to the bottom of the rotating rod, and a scraper is fixedly connected to the bottom of the insert rod.

[0012] The above technical solution provides power to the rotating rod of the scraping component, which in turn drives the insertion rod and the scraper at the bottom to operate, thus accurately cleaning the surface of the filter screen, ensuring the normal screening function of the filter screen, improving the separation efficiency of coal lumps and coal powder, and the insertion rod can be detached for easy replacement of the scraper.

[0013] As a further description of the above technical solution:

[0014] Arc-shaped plates are fixedly connected to both the front and rear sides of the scraper, and the bottom sides of the two arc-shaped plates are in contact with the top side of the filter screen.

[0015] Through the above technical solution: the arc-shaped plates on both sides of the scraper contact the top side of the filter screen. During the movement of the scraper, the arc-shaped plates can more comprehensively scrape the coal lumps stuck on the surface of the filter screen, prevent the coal lumps from accumulating in the corners of the filter screen, further improve the cleaning effect of the filter screen, and ensure the efficiency and continuity of screening.

[0016] As a further description of the above technical solution:

[0017] A crushing motor is fixedly connected to the front end of the crushing box, and a crushing shaft is fixedly connected to the drive end of the crushing motor.

[0018] The above technical solution involves a crushing motor at the front of the crushing box driving the crushing shaft to crush the coal blocks in the collection box into coal powder, thereby improving the utilization rate of coal resources, avoiding coal waste, realizing the secondary utilization of resources, and reducing production costs.

[0019] As a further description of the above technical solution:

[0020] The conveying assembly includes a conveying pipe, the left side of which is fixedly connected to the output end of the conveying pipe, and an auger is provided inside the conveying pipe;

[0021] The above technical solution involves a conveying pipe in the conveying assembly for transporting pulverized coal. An internal auger rotates to move the pulverized coal, efficiently transporting the crushed coal to a designated location, ensuring smooth material transport throughout the entire device, and guaranteeing the smooth operation of the pulverized coal recycling process.

[0022] As a further description of the above technical solution:

[0023] The top end of the conveying pipe is fixedly connected to a discharge port, and the bottom end of the discharge port is fixedly connected to the top of the discharge hopper.

[0024] The above technical solution connects the discharge port at the top of the conveying pipe to the top of the hopper, allowing the recycled coal powder to return smoothly to the hopper and rejoin the operation of the device. This achieves a closed loop in the coal powder recycling path, improves the utilization rate of coal powder, reduces coal powder waste, and further optimizes the resource utilization efficiency of the device.

[0025] As a further description of the above technical solution:

[0026] The disassembly and assembly mechanism includes a cylindrical block. The top end of the cylindrical block is fixedly connected to the bottom end of the rotating rod. The top outer wall of the insertion rod is slidably connected to the inner wall of the cylindrical block. Circular grooves are provided on both the left and right sides inside the cylindrical block. A return spring is fixedly connected to the inner wall of the two circular grooves on the far side. A ball head locking block is fixedly connected to the close side of the two return springs.

[0027] Through the above technical solution: the cylindrical block of the disassembly and assembly mechanism provides an installation base for other components. The return spring and the ball head locking block cooperate with each other. When the insertion rod is inserted into the cylindrical block, the ball head locking block is locked into the insertion rod under the action of the return spring, realizing quick fixation. When disassembling, the return spring is compressed and the ball head locking block retracts, which facilitates the disassembly of the insertion rod and greatly improves the efficiency of replacing parts during equipment maintenance.

[0028] As a further description of the above technical solution:

[0029] The outer wall of the ball head block is slidably connected to the inner wall of the circular groove, and the adjacent sides of the two ball head blocks are in contact with the inside of the insertion rod;

[0030] Through the above technical solution, the outer wall of the ball head block slides in the circular groove, ensuring smooth movement of the ball head block and precise contact or disengagement with the inside of the insertion rod. This ensures the convenience and safety of component replacement during equipment maintenance and improves the overall maintenance efficiency of the equipment.

[0031] This utility model has the following beneficial effects:

[0032] 1. In this utility model, a filter screen is provided in the hopper to separate coal powder and coal lumps. Coal lumps that do not pass through the filter screen are scraped by the scraper to the slag discharge port and fall into the collection box, and then enter the crushing box. The crushing motor drives the crushing shaft to crush the coal lumps. The crushed coal powder is then returned to the hopper through the conveying pipe, auger, conveying pipe and discharge port. Through this recycling process, the originally discarded coal lumps are transformed back into usable coal powder, thereby improving the utilization rate of coal resources.

[0033] 2. In this utility model, when the insert rod is connected to the cylindrical block, the ball head locking block is locked into the groove of the insert rod under the action of the return spring to achieve fixation. When it is necessary to replace or maintain the scraper, the insert rod is pulled outward, the ball head locking block retracts into the circular groove, and the insert rod can be separated from the cylindrical block. This convenient disassembly and assembly method reduces maintenance time and thus improves the working efficiency of the entire device. Attached Figure Description

[0034] Figure 1 This is a perspective view of a coal injection device for a decomposition furnace proposed in this utility model;

[0035] Figure 2This is a schematic diagram of the structure of the feeding hopper of a coal injection device for a decomposition furnace proposed in this utility model;

[0036] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0037] Figure 4 for Figure 2 Enlarged view of point B in the middle.

[0038] Legend:

[0039] 1. Base; 2. Rotary kiln coal mill pulverizer; 3. Control switch box; 4. Feed hopper; 5. Recycling mechanism; 501. Support plate; 502. Motor; 503. Rotating rod; 504. Insert rod; 505. Scraper; 506. Filter screen; 507. Slag discharge port; 508. Collection box; 509. Crushing box; 510. Crushing motor; 511. Crushing shaft; 512. Conveying pipe; 513. Feeding pipe; 514. Screwdriver; 515. Feed port; 6. Disassembly and assembly mechanism; 601. Cylindrical block; 602. Circular groove; 603. Return spring; 604. Ball head retainer. Detailed Implementation

[0040] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0041] Reference Figure 1 , Figure 2 and Figure 4 This utility model provides an embodiment of a coal injection device for a decomposition furnace, comprising a base 1, which is the supporting foundation of the entire device. It is made of high-strength steel and has stable load-bearing capacity and vibration resistance. The surface is treated with anti-rust to adapt to the high dust environment of cement production workshops. A rotary kiln coal mill coal injection machine 2 is fixedly connected to the top of the base 1. As the core working component, it is made of high-temperature resistant alloy material and can realize the fine grinding and injection function of coal powder. A control switch box 3 is fixedly connected to the right end of the rotary kiln coal mill coal injection machine 2. It is assembled with explosion-proof electrical components and integrates motor control, speed adjustment and fault alarm functions. The panel is equipped with an emergency stop button and a running indicator light to facilitate operators to monitor the equipment status in real time. A feeding hopper 4 is fixedly connected to the top of the control switch box 3. The feeding hopper 4 is the inlet for coal powder to enter the device and provides a channel for coal powder transportation. A recycling mechanism 5 is fixedly connected inside the feeding hopper 4. A disassembly and assembly mechanism 6 is set inside the recycling mechanism 5.

[0042] Specifically, the base 1 is made of high-strength steel and has a rust-proof surface treatment to ensure stable load-bearing and vibration resistance in high dust environments, providing a reliable support foundation for the device. The rotary kiln coal mill pulverizer 2 is made of high-temperature resistant alloy material to ensure the realization of fine coal grinding and injection functions. The control switch box 3 integrates multiple functions and is equipped with an emergency stop button and indicator lights, which facilitates operators to monitor the equipment status in real time and improves the convenience and safety of operation.

[0043] The recycling mechanism 5 includes a support plate 501, the outer wall of which is fixedly connected to the inner wall of the hopper 4. A scraping assembly is fixedly connected to the bottom end of the support plate 501. The scraping assembly includes a motor 502, the top end of which is fixedly connected to the bottom end of the support plate 501. The support plate 501 can stably fix the motor 502 and other components, ensuring that the scraping assembly and the entire recycling mechanism 5 can operate normally. A rotating rod 503 is fixedly connected to the output end of the motor 502. The motor 502 is the power source for the scraping assembly, and it drives the rotating rod 503 to rotate by generating power. A rod 504 is detachably connected to the bottom of 503. A scraper 505 is fixedly connected to the bottom end of the rod 504. The rod 504 connects the rotating rod 503 and the scraper 505. On the one hand, the rod 504 transmits the power of the rotating rod 503 to the scraper 505. On the other hand, it cooperates with the disassembly and assembly mechanism 6 to realize the convenient disassembly and assembly of the scraper 505. A filter screen 506 is installed on the inner wall of the hopper 4. Arc-shaped plates are fixedly connected to both the front and rear sides of the scraper 505. The bottom sides of the two arc-shaped plates are in contact with the top side of the filter screen 506. A slag discharge port 507 is opened on the right side of the inside of the hopper 4. 05 acts directly on the surface of filter screen 506, scraping and pushing coal lumps stuck on the surface of filter screen 506 towards the slag discharge port 507, ensuring the normal operation of the screening function of filter screen 506, allowing fine coal powder to pass smoothly through filter screen 506 into the rotary kiln coal mill pulverizer 2, while intercepting larger coal lumps on the surface of filter screen 506, achieving effective separation of coal lumps and coal powder. A collection box 508 is fixedly connected to the right side of the slag discharge port 507, providing a discharge channel for coal lumps that have not passed through filter screen 506. Under the push of scraper 505, the coal lumps fall into the collection box 507 through the slag discharge port 507. 8. A crushing box 509 is fixedly connected to the bottom of the collection box 508. The collection box 508 is used to temporarily store coal blocks to prevent them from scattering and to provide a transition for the coal blocks to enter the crushing box 509, ensuring that the coal blocks can enter the next processing stage in an orderly manner. A crushing motor 510 is fixedly connected to the front end of the crushing box 509. A crushing shaft 511 is fixedly connected to the drive end of the crushing motor 510. Under the drive of the crushing motor 510, the crushing shaft 511 crushes the coal blocks, crushing larger coal blocks into coal powder that meets the requirements for reuse, thereby improving the utilization rate of coal resources.

[0044] Specifically, the recycling mechanism 5 drives the scraper 505 via the motor 502 to effectively clean the coal lumps on the surface of the filter screen 506, ensuring the normal screening function of the filter screen and achieving efficient separation of coal lumps and coal powder. The slag discharge port 507 works in conjunction with the collection box 508 to orderly discharge and store coal lumps that have not passed through the filter screen, preventing them from scattering. The crushing box 509 and its internal crushing motor 510, crushing shaft 511 and other components crush the coal lumps into coal powder, significantly improving the utilization rate of coal resources.

[0045] A conveying pipe 512 is fixedly connected to the bottom end of the crushing box 509. A conveying assembly is fixedly connected to the output end of the conveying pipe 512. The conveying assembly includes a feeding pipe 513. The left side of the feeding pipe 513 is fixedly connected to the output end of the conveying pipe 512. The conveying pipe 512 is responsible for conveying the crushed coal powder to the feeding pipe 513. An auger 514 is installed inside the feeding pipe 513. The feeding pipe 513 is the main pipe for conveying the crushed coal powder. A discharge port 515 is fixedly connected to the top end of the feeding pipe 513 for discharging. The bottom of the discharge port 515 is fixedly connected to the top of the hopper 4. The auger 514 uses its own spiral structure to push the coal powder to move in the conveying pipe 513, and stably convey the coal powder from the conveying pipe 512 upward, ensuring that the coal powder can reach the discharge port 515, thus realizing the effective conveying of the coal powder. The discharge port 515 is the inlet for the coal powder to re-enter the hopper 4. The recycled coal powder is sent back to the hopper 4, so that the coal powder can participate in the operation of the whole device again, realizing the recycling and reuse of coal powder.

[0046] Specifically, the conveying component uses the auger 514 to push the pulverized coal powder to move within the conveying pipe 513, thereby achieving stable conveying of the pulverized coal powder and ensuring that the pulverized coal powder can re-enter the feed hopper 4 to participate in the operation of the device, achieving coal powder recycling and reuse, and saving resources.

[0047] Reference Figure 1 , Figure 2 and Figure 3The disassembly and assembly mechanism 6 includes a cylindrical block 601. The top end of the cylindrical block 601 is fixedly connected to the bottom end of the rotating rod 503. The top outer wall of the insertion rod 504 is slidably connected to the inner wall of the cylindrical block 601. Circular grooves 602 are provided on both the left and right sides inside the cylindrical block 601. A return spring 603 is fixedly connected to the inner wall of the two circular grooves 602 on the far side. A ball head locking block 604 is fixedly connected to the close side of the two return springs 603. The outer wall of the ball head locking block 604 is slidably connected to the inner wall of the circular groove 602. The close side of the two ball head locking blocks 604 is in contact with the inside of the insertion rod 504. The return spring 603 is the ball head locking block 604. 04 provides elasticity. When the insertion rod 504 is inserted into the cylindrical block 601, the return spring 603 pushes the ball head latch 604 into the groove inside the insertion rod 504 to achieve quick fixation. When the insertion rod 504 is disassembled, the return spring 603 is compressed, allowing the ball head latch 604 to retract into the circular groove 602. The cylindrical block 601 is an important component of the disassembly and assembly mechanism 6, providing installation space for components such as the ball head latch 604. The circular groove 602 provides installation space for the return spring 603 and the ball head latch 604, and limits the sliding range of the ball head latch 604, ensuring that the ball head latch 604 can properly engage and disengage the insertion rod 504.

[0048] Specifically, the disassembly and assembly mechanism 6 uses a return spring 603 and a ball head locking block 604 to achieve quick installation and disassembly of the insertion rod 504, which facilitates the replacement of the scraper 505, improves equipment maintenance efficiency, and ensures continuous and stable operation of the equipment.

[0049] Working principle: After the coal powder enters the device from the feed hopper 4, it is first screened through the filter screen 506. The fine coal powder passes through the filter screen 506 and enters the rotary kiln coal mill pulverizer 2, while the coal lumps that fail to pass through the filter screen 506 remain on the surface of the filter screen 506. At this time, the motor 502 drives the rotating rod 503 to rotate, which drives the scraper 505 to scrape along the surface of the filter screen 506 and push the coal lumps to the slag discharge port 507. The coal lumps fall into the collection box 508 through the slag discharge port 507, and then enter the crushing box 509. The crushing motor 510 drives the crushing shaft 511 to crush the coal lumps. The crushed coal powder is conveyed to the conveying pipe 513 through the conveying pipe 512 and the auger 514, and finally re-enters the feed hopper 4 through the discharge port 515, realizing the recycling and reuse of coal lumps.

[0050] When the scraper 505 needs to be replaced or maintained, the disassembly and assembly mechanism 6 comes into play. The insertion rod 504 is connected to the cylindrical block 601 through the ball head locking block 604 at the top. Under the action of the return spring 603, the ball head locking block 604 is locked into the groove inside the insertion rod 504, achieving quick fixation. When disassembling, the insertion rod 504 is pulled outward, and the ball head locking block 604 is compressed back into the circular groove 602. The return spring 603 is compressed, and the insertion rod 504 can be separated from the cylindrical block 601, realizing convenient disassembly and assembly of the scraper 505 and improving maintenance efficiency.

[0051] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. 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 coal injection device for a decomposition furnace, comprising a base (1), characterized in that: A rotary kiln coal mill pulverizer (2) is fixedly connected to the top of the base (1). A control switch box (3) is fixedly connected to the right end of the rotary kiln coal mill pulverizer (2). A feeding hopper (4) is fixedly connected to the top of the control switch box (3). A recycling mechanism (5) is fixedly connected inside the feeding hopper (4). A disassembly and assembly mechanism (6) is provided inside the recycling mechanism (5). The recycling mechanism (5) includes a support plate (501), the outer wall of which is fixedly connected to the inner wall of the hopper (4), a scraping component is fixedly connected to the bottom end of the support plate (501), a filter screen (506) is installed on the inner wall of the hopper (4), a slag discharge port (507) is opened on the right side of the hopper (4), a collection box (508) is fixedly connected to the right side of the slag discharge port (507), a crushing box (509) is fixedly connected to the bottom end of the collection box (508), a conveying pipe (512) is fixedly connected to the bottom end of the crushing box (509), and a conveying component is fixedly connected to the output end of the conveying pipe (512).

2. The pulverized coal injection device for a decomposition furnace according to claim 1, characterized in that: The scraping assembly includes a motor (502), the top end of which is fixedly connected to the bottom end of the support plate (501), the output end of which is fixedly connected to a rotating rod (503), the bottom of which is detachably connected to an insert rod (504), and the bottom end of which is fixedly connected to a scraper (505).

3. The pulverized coal injection device for a decomposition furnace according to claim 2, characterized in that: Arc-shaped plates are fixedly connected to both the front and rear sides of the scraper (505), and the bottom sides of the two arc-shaped plates are in contact with the top side of the filter screen (506).

4. The pulverized coal injection device for a decomposition furnace according to claim 1, characterized in that: The front end of the crushing box (509) is fixedly connected to a crushing motor (510), and the drive end of the crushing motor (510) is fixedly connected to a crushing shaft (511).

5. The pulverized coal injection device for a decomposition furnace according to claim 1, characterized in that: The conveying assembly includes a conveying pipe (513), the left side of which is fixedly connected to the output end of the conveying pipe (512), and an auger (514) is provided inside the conveying pipe (513).

6. The pulverized coal injection device for a decomposition furnace according to claim 5, characterized in that: The top end of the conveying pipe (513) is fixedly connected to the discharge port (515), and the bottom end of the discharge port (515) is fixedly connected to the top of the discharge hopper (4).

7. The pulverized coal injection device for a decomposition furnace according to claim 2, characterized in that: The disassembly and assembly mechanism (6) includes a cylindrical block (601), the top end of which is fixedly connected to the bottom end of the rotating rod (503), and the top outer wall of the insertion rod (504) is slidably connected to the inner wall of the cylindrical block (601). Circular grooves (602) are provided on both the left and right sides inside the cylindrical block (601). A return spring (603) is fixedly connected to the inner wall of the two circular grooves (602) on the far side, and a ball head block (604) is fixedly connected to the near side of the two return springs (603).

8. A coal injection device for a decomposition furnace according to claim 7, characterized in that: The outer wall of the ball head block (604) is slidably connected to the inner wall of the circular groove (602), and the adjacent sides of the two ball head blocks (604) are in contact with the interior of the insertion rod (504).

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