A valve seat tool

Abstract

The application relates to the technical field of valve maintenance, and discloses a valve seat assembling and disassembling tool which comprises an outer pressing plate, a pressing rod is fixedly connected in the inner part of the outer pressing plate, a fastening screw is threadedly connected in the inner part of the pressing rod, a soft jaw is arranged at the bottom end of the pressing rod, a pre-buried nut is arranged in the inner part of the soft jaw, the pressing rod and the soft jaw are connected through the fastening screw and the pre-buried nut, a valve body is arranged on the lower surface of the outer pressing plate, a connecting screw is threadedly connected in the inner part of the outer pressing plate, the outer pressing plate and the valve body are connected through the connecting screw, and the outer wall of the pressing rod is slidingly connected in the inner part of the valve body. By rotating the inner rod, the conical body is driven to move upwards along the inner rod, axial pressure is applied to the soft jaw, the soft jaw is radially expanded, the inner wall of the valve seat body is tightly pressed, the inner rod and the pressing rod are lifted, the valve seat body can be taken out of the valve body, and the sealing surface of the valve seat body and the inner wall of the valve body can be effectively prevented from being damaged.

Description

Technical Field

[0001] The invention relates to the technical field of valve maintenance, in particular to a tool for assembling and disassembling a valve seat. Background Art

[0002] Special tools are required for installing and removing the valve seat. When repairing the valve, the valve must be disassembled to check the degree of wear of the valve body, valve core, and valve seat sealing surface, and the sealing surface must be repaired and reassembled. Special tools are required for fastening the valve seat. Usually, the same valve seat wrench is used for disassembly and installation of the valve seat. For general single-seat valves, the valve seat can be directly removed by directly reversing the installation valve seat wrench to unscrew all the valve seat threads.

[0003] However, in the maintenance scenario of ultra-low temperature core-pulling valves, since the valve seat is deeply buried in the narrow inner cavity of the valve body and the valve port diameter is limited, although the traditional valve seat wrench can complete the thread loosening operation, it is impossible to grab and remove the valve seat from the deep cavity without damage. The existing technology relies on blunt tools such as hooks to forcibly hook it, which can easily cause scratches on the valve seat sealing surface or the inner wall of the valve body, destroying the integrity of the sealing structure, thereby causing media leakage, shortening the valve life, and significantly increasing the cost of maintenance rework and material replacement. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides a valve seat assembly and disassembly tool, which solves the problem that the existing tools lack mechanical grasping capabilities and rely on manual operation when removing parts from deep cavities, resulting in damage to the sealing structure.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0006] The cam is fixedly connected to the valve seat by a pressure rod passing through the interior of the outer pressure plate, and a fastening screw is threadedly connected to the interior of the pressure rod. The bottom end of the pressure rod is provided with a soft claw, and an embedded nut is provided inside the soft claw. The pressure rod and the soft claw are connected by the fastening screw and the embedded nut. The lower surface of the outer pressure plate is provided with a valve body, and the interior of the outer pressure plate is threadedly connected with a connecting screw. The outer pressure plate and the valve body are connected by the connecting screw. The outer wall of the pressure rod is slidably connected to the interior of the valve body, and a valve seat body is provided inside the valve body. The outer wall of the soft claw is fixedly connected to an anti-slip pad, and the outer walls of the soft claw and the anti-slip pad are both fitted to the inner wall of the valve seat body. The internal thread of the pressure rod is connected to an inner rod, and the outer wall of the inner rod is slidably connected to the interior of the soft claw, and the bottom end of the inner rod is provided with a connecting mechanism.

[0007] By adopting the above technical solution: by rotating the inner rod, the tapered body moves upward under the drive of the inner rod, and then applies axial pressure to the soft claw, causing it to expand radially, thereby tightening the inner wall of the valve seat body, lifting the inner rod and the pressure rod, and then the valve seat body can be taken out of the valve body, thereby effectively avoiding damage to the sealing surface of the valve seat body and the inner wall of the valve body, and thus ensuring the integrity of the sealing structure during the disassembly process.

[0008] Preferably, the connecting mechanism includes a tapered body, the outer wall of the tapered body is arranged at the bottom end of the inner rod, the outer wall of the tapered body is slidably connected to the inside of the soft claw, the internal thread of the tapered body is connected to a locking nut, and the outer wall of the locking nut is threadedly connected to the inside of the inner rod.

[0009] Preferably, the connecting mechanism includes a screw rod, the top end of the screw rod is fixedly connected to the bottom end of the inner rod, and the outer wall of the inner rod is threadedly connected to the inside of the tapered body.

[0010] Preferably, the outer wall of the tapered body is fixedly connected to a connecting cylinder, and the inner walls of the tapered body and the connecting cylinder are both slidably connected to the outer wall of the inner rod.

[0011] Preferably, the outer wall of the inner rod is fixedly connected to a limiting ring, and the outer walls of the anti-slip pad and the limiting ring are both rotatably connected to the inner wall of the pressure rod.

[0012] Preferably, the interior of the soft claw is fixedly connected to a limiting cylinder, the inner wall of the limiting cylinder is fixedly connected to a clamping block, and the outer wall of the clamping block is slidably connected to the outer wall of the connecting cylinder.

[0013] Preferably, the outer wall of the clamping block is fixedly connected to a telescopic rod, the outer wall of the telescopic rod is fixedly connected to the inner wall of the limiting cylinder, and a spring is provided inside the limiting cylinder.

[0014] Preferably, one end of the spring is fixed to the clamping block, and the other end abuts against the inner wall of the limiting cylinder, and the outer wall of the spring is slidably connected to the outer wall of the telescopic rod.

[0015] Preferably, a slot is provided on the outer wall of the connecting tube, and the outer wall of the clamping block is slidably connected to the inner wall of the slot.

[0016] Preferably, a color ring column is provided inside the inner rod, and when the tapered body rises, it drives the color ring column to slide in the inner rod.

[0017] Working Principle: When using this tool, first insert the pressure rod together with the inner rod into the valve body, then fix the outer pressure plate to the valve body with the connecting screws. By turning the pressure rod, the soft claws rotate, and the anti-slip pad can be used to loosen the threads of the valve seat body. Then, turn the inner rod. As the inner rod rotates in the pressure rod, it drives the tapered body upward, squeezing the soft claws to expand radially, thereby tightening the inner wall of the valve seat body. Then, loosen the connecting screws on the outer pressure plate, lift the inner rod and pressure rod, and then the valve seat body can be taken out of the valve body.

[0018] Similarly, after inserting the pressure rod and the inner rod into the valve body, the outer pressure plate is fixed to the valve body with the connecting screws. By rotating the pressure rod, the soft claw rotates. Under the action of the anti-slip pad, the thread of the valve seat body can be loosened. Then the inner rod is rotated, and the screw rod is driven by the inner rod to rotate. The screw rod drives the tapered body and the connecting cylinder to slide on the inner rod. As the connecting cylinder slides on the inner rod, it also slides relative to the block, squeezing the block to slide in the limit cylinder. The block squeezes the telescopic rod and the spring to be compressed at the same time. When the block slides into the slot, the spring rebounds and the block is firmly stuck in the slot. At this time, the tapered body squeezes the soft claw and expands it radially while moving upward, thereby tightening the inner wall of the valve seat body. As the tapered body moves upward, it also pushes the color ring column to slide in the inner rod. The color change of the color ring column can display the radial expansion degree of the soft claw in real time. Then, lift the inner rod and pressure rod, and the valve seat body can be removed from the valve body.

[0019] The present invention provides a tool for installing and removing a valve seat. It has the following beneficial effects:

[0020] 1. The present invention rotates the inner rod, and the tapered body moves upward under the drive of the inner rod, thereby applying axial pressure to the soft claws, causing them to expand radially, thereby tightening the inner wall of the valve seat body, lifting the inner rod and the pressure rod, and then the valve seat body can be brought out of the valve body, thereby effectively avoiding damage to the sealing surface of the valve seat body and the inner wall of the valve body.

[0021] 2. The present invention provides a card slot on the connecting tube and utilizes the cooperation of the card block, telescopic rod and spring. When the card block slides into the card slot, the spring rebounds to firmly lock the card block. The tapered body and the soft claw can be firmly connected without manual continuous force, effectively preventing loosening due to external force during the grasping process and ensuring the stability of the loading and unloading process.

[0022] 3. This invention incorporates a color ring column within the inner rod. As the tapered body moves upward, the color ring slides with it, and its color change intuitively reflects the radial expansion of the soft jaw. This design allows the operator to monitor the expansion status of the soft jaw in real time, ensuring uniform tension on the valve seat body and preventing damage caused by insufficient or excessive expansion, thereby improving assembly and disassembly accuracy and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A cross-sectional view of a valve seat assembly and disassembly tool according to the present invention;

[0024] Figure 2 A three-dimensional tool for assembling and disassembling valve seat according to the present invention Figure 1 ;

[0025] Figure 3 A three-dimensional tool for assembling and disassembling valve seat according to the present invention Figure 2 ;

[0026] Figure 4 This is a schematic diagram of the inner rod structure of a valve seat installation and removal tool of the present invention;

[0027] Figure 5 This is a schematic diagram of the partial structure of the tapered body of a valve seat assembly and disassembly tool of the present invention;

[0028] Figure 6 This is a schematic diagram of the partial structure of a spring for a valve seat assembly and disassembly tool according to the present invention;

[0029] Figure 7 The figure is a schematic diagram of the local structure of a screw rod of a valve seat installation and removal tool of the present invention.

[0030] Among them, 1. Outer pressure plate; 2. Inner rod; 3. Pressure rod; 4. Fastening screw; 5. Embedded nut; 6. Soft claw; 7. Valve body; 8. Valve seat body; 9. Tapered body; 10. Lock nut; 11. Connecting screw; 12. Anti-slip pad; 13. Limiting ring; 14. Slot; 15. Screw; 16. Limiting cylinder; 17. Block; 18. Telescopic rod; 19. Spring; 20. Color ring column; 21. Connecting cylinder. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] Please see the attached Figure 1 and attached Figure 2, an embodiment of the present invention provides a valve seat loading and unloading tool, including an outer pressure plate 1, the inner part of the outer pressure plate 1 is fixedly connected with a pressure rod 3, the inner part of the pressure rod 3 is threadedly connected with a fastening screw 4, the bottom end of the pressure rod 3 is provided with a soft claw 6, and the inner part of the soft claw 6 is provided with an embedded nut 5, the pressure rod 3 and the soft claw 6 are connected by the fastening screw 4 and the embedded nut 5, the lower surface of the outer pressure plate 1 is provided with a valve body 7, the inner part of the outer pressure plate 1 is threadedly connected with a connecting screw 11, the outer pressure plate 1 and the valve body 7 are connected by the connecting screw 11, the outer wall of the pressure rod 3 is slidably connected to the inner part of the valve body 7, and the inner part of the valve body 7 is provided with a valve seat body 8, the outer wall of the soft claw 6 is fixedly connected with an anti-slip pad 12, and the outer walls of the soft claw 6 and the anti-slip pad 12 are both fitted against the inner wall of the valve seat body 8, the inner part of the pressure rod 3 is threadedly connected to the inner rod 2, the outer wall of the inner rod 2 is slidably connected to the inner part of the soft claw 6, and the bottom end of the inner rod 2 is provided with a connecting mechanism.

[0033] After the jacks have been loosened, the jacks 11 are tightened, and the jacks 12 are tightened, which in turn loosens the jacks 12. When the jacks 12 are loose, the jacks 12 are tightened, and the jacks 12 are tightened. The function of loosening the thread of the valve seat body 8 is that the top of the pressure rod 3 is milled with a hexagonal shape, which is convenient for rotating with tools. At the same time, the middle of the pressure rod 3 cooperates with the hole in the outer pressure plate 1 to guide, so that the pressure rod 3 can move linearly in the center line of the valve body 7, thereby ensuring that the valve seat body 8 is always perpendicular to the center line of the valve body 7 during the disassembly process, avoiding damage to the sealing surface of the valve seat body 8 and the inner wall of the valve body 7. The outer circle of the large outer circle of the soft claw 6 has four protrusions, which cooperate with the groove of the valve seat body 8 to rotate the valve seat body 8. The small outer circle of the bottom of the soft claw 6 is consistent with the size of the inner hole of the valve seat body 8, and is embossed on the outer side of the outer circle, which can increase the friction when removing the valve seat and more reliably remove the valve seat. The bottom of the soft claw 6 is milled with four grooves, which can form four petal-type non-metallic soft claws 6 when squeezed upward by the tapered body 9, converting the axial force into radial expansion force, firmly grasping the valve seat body 8. The material of the soft claw 6 is non-metallic PTFE, which not only ensures the flexibility of the soft claw 6, but also avoids scratching the sealing surface of the valve body 7.

[0034] Please see the attached Figure 1 and attached Figure 2The connecting mechanism includes a tapered body 9, the outer wall of the tapered body 9 is arranged at the bottom end of the inner rod 2, the outer wall of the tapered body 9 is slidably connected to the inside of the soft claw 6, the internal thread of the tapered body 9 is connected to the locking nut 10, and the outer wall of the locking nut 10 is threadedly connected to the inside of the inner rod 2.

[0035] Specifically, the locking nut 10 is used to fasten the tapered body 9 to the bottom end of the inner rod 2, ensuring that no relative movement occurs between the tapered body 9 and the inner rod 2, while allowing the tapered body 9 to be conveniently disassembled and replaced when needed. During the upward movement of the tapered body 9, its tapered design enables it to squeeze the bottom of the soft claw 6, causing the soft claw 6 to expand radially, thereby enabling the soft claw 6 to fit tightly against the inner wall of the valve seat body 8, and at the same time providing the necessary support force for subsequently removing the valve seat body 8 from the valve body 7.

[0036] Please see the attached Figure 2 -Attached Figure 7 The connecting mechanism includes a screw rod 15, the top of the screw rod 15 is fixedly connected to the bottom end of the inner rod 2, and the outer wall of the inner rod 2 is threadedly connected to the inside of the tapered body 9; the outer wall of the tapered body 9 is fixedly connected to the connecting cylinder 21, and the inner walls of the tapered body 9 and the connecting cylinder 21 are both slidably connected to the outer wall of the inner rod 2; the outer wall of the inner rod 2 is fixedly connected to the limiting ring 13, and the outer walls of the anti-slip pad 12 and the limiting ring 13 are rotatably connected to the inner wall of the pressure rod 3; the interior of the soft claw 6 is fixedly connected to the limiting cylinder 16, and the inner wall of the limiting cylinder 16 is fixedly connected The outer wall of the block 17 is slidably connected to the outer wall of the connecting tube 21; the outer wall of the block 17 is fixedly connected to the telescopic rod 18, the outer wall of the telescopic rod 18 is fixedly connected to the inner wall of the limiting tube 16, and a spring 19 is provided inside the limiting tube 16; one end of the spring 19 is fixed to the block 17, and the other end abuts the inner wall of the limiting tube 16, and the outer wall of the spring 19 is slidably connected to the outer wall of the telescopic rod 18; the outer wall of the connecting tube 21 is provided with a card slot 14, and the outer wall of the block 17 is slidably connected to the inner wall of the card slot 14.

[0037] Specifically, the inner rod 2 is rotated, and the inner rod 2 plays the role of driving the screw rod 15 to rotate and rotate, and the screw rod 15 drives the tapered body 9 and the connecting cylinder 21 to slide on the inner rod 2, and then gradually approaches the soft claw 6, in preparation for the subsequent squeezing of the soft claw 6. When the connecting cylinder 21 slides on the inner rod 2, it will slide relative to the block 17, thereby squeezing the block 17 to make it slide in the limit cylinder 16, and squeezing the telescopic rod 18 and the spring 19 through the block 17 and compressing them at the same time. When the block 17 slides into the slot 14, under the rebound action of the spring 19, the block 17 is firmly stuck. The action in the card slot 14 and the connecting tube 21 realize the firm connection between the tapered body 9 and the soft claw 6, providing a guarantee for the subsequent squeezing of the soft claw 6 by the tapered body 9. At the same time, the firm connection between the tapered body 9 and the soft claw 6 can be maintained without continuous manual force, effectively preventing the loosening caused by external force during the grasping process, ensuring the stability of the loading and unloading process. At this time, the tapered body 9 squeezes the soft claw 6 and expands it radially while moving upward, thereby achieving the effect of tightening the inner wall of the valve seat body 8, wherein the limit ring 13 limits the axial movement range of the inner rod 2, and at the same time ensures the smooth rotation of the inner rod 2 on the inner wall of the pressure rod 3, ensuring the stability of the entire connecting mechanism.

[0038] Please see the attached Figure 2 , Attachment Figure 3 , Attachment Figure 4 and attached Figure 7 A color ring column 20 is provided inside the inner rod 2. When the tapered body 9 rises, it drives the color ring column 20 to slide in the inner rod 2.

[0039] Specifically, as the tapered body 9 moves upward, it also pushes the color ring column 20 to slide in the inner rod 2. The color change of the extended color ring column 20 achieves the effect of displaying the radial expansion degree of the soft claw 6 in real time. The color ring column 20 and the tapered body 9 are not fixedly connected. As the inner rod 2 rotates, the color ring column 20 and the tapered body 9 will cause relative sliding between them. By displaying the radial expansion degree of the soft claw 6 in real time, the color ring column 20 helps the operator avoid damage to the valve seat or valve body 7 caused by excessive expansion, thereby enhancing the safety of the loading and unloading process. Three color bands of green, yellow and red can be provided in the upper part of the color ring column 20 from top to bottom. Green is used to indicate the initial state or normal expansion degree of the soft claw 6, providing the operator with safe and normal visual feedback; yellow is used to indicate that the soft claw 6 has begun to enter the expansion state, but has not yet reached a level that requires special attention, reminding the operator to pay attention; red is used to indicate that the soft claw 6 has expanded to a level close to or exceeding the safety limit, and the operator needs to take immediate action.

[0040] Example 1: When using this tool, first insert the pressure rod 3 together with the inner rod 2 into the valve body 7, then fix the outer pressure plate 1 to the valve body 7 using the connecting screw 11. By rotating the pressure rod 3, the soft claw 6 is rotated, and the anti-slip pad 12 can be used to loosen the thread of the valve seat body 8;

[0041] Then rotate the inner rod 2. As the inner rod 2 rotates in the pressure rod 3, it will drive the tapered body 9 to move upward, thereby squeezing the soft claws 6 to expand radially, thereby tightening the inner wall of the valve seat body 8. Then loosen the connecting screws 11 on the outer pressure plate 1, lift the inner rod 2 and the pressure rod 3, and then the valve seat body 8 can be taken out of the valve body 7.

[0042] Example 2: After the pressure rod 3 and the inner rod 2 are inserted into the valve body 7, the outer pressure plate 1 is fixed to the valve body 7 by the connecting screw 11. By rotating the pressure rod 3, the soft claw 6 is driven to rotate, and the thread of the valve seat body 8 can be loosened under the action of the anti-slip pad 12;

[0043] Then, the inner rod 2 is rotated, and the screw rod 15 is driven to rotate through the inner rod 2, and the screw rod 15 drives the tapered body 9 and the connecting cylinder 21 to slide on the inner rod 2. While the connecting cylinder 21 slides on the inner rod 2, it also slides relative to the block 17, thereby squeezing the block 17 to slide in the limiting cylinder 16. The block 17 squeezes the telescopic rod 18 and the spring 19 to compress them at the same time. When the block 17 slides into the slot 14, the rebound of the spring 19 makes the block 17 firmly stuck in the slot 14. At this time, the tapered body 9 squeezes the soft claw 6 while moving upward, causing it to expand radially, thereby tightening the inner wall of the valve seat body 8;

[0044] As the tapered body 9 moves upward, it also pushes the color ring column 20 to slide in the inner rod 2. The color change of the extended color ring column 20 can display the radial expansion degree of the soft claw 6 in real time. Then, the inner rod 2 and the pressure rod 3 are lifted, and the valve seat body 8 can be taken out of the valve body 7.

[0045] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A valve seat assembly and disassembly tool, comprising an outer pressure plate (1), characterized in that: The interior of the outer pressure plate (1) is fixedly connected with a pressure rod (3), the interior of the pressure rod (3) is threadedly connected with a fastening screw (4), the bottom end of the pressure rod (3) is provided with a soft claw (6), the interior of the soft claw (6) is provided with an embedded nut (5), the pressure rod (3) and the soft claw (6) are connected by the fastening screw (4) and the embedded nut (5), the lower surface of the outer pressure plate (1) is provided with a valve body (7), the interior of the outer pressure plate (1) is threadedly connected with a connecting screw (11), The outer pressure plate (1) and the valve body (7) are connected by connecting screws (11), the outer wall of the pressure rod (3) is slidably connected to the inside of the valve body (7), the valve seat body (8) is provided inside the valve body (7), the outer wall of the soft claw (6) is fixedly connected to the anti-slip pad (12), the outer walls of the soft claw (6) and the anti-slip pad (12) are both attached to the inner wall of the valve seat body (8), the inner thread of the pressure rod (3) is connected to the inner rod (2), the outer wall of the inner rod (2) is slidably connected to the inner wall of the soft claw (6), and the outer wall of the inner rod (2) is slidably connected to the inner wall of the soft claw (6). The bottom end of the inner rod (2) is provided with a connecting mechanism, the connecting mechanism includes a tapered body (9), the outer wall of the tapered body (9) is provided at the bottom end of the inner rod (2), the outer wall of the tapered body (9) is slidably connected to the inside of the soft claw (6), the inner thread of the tapered body (9) is connected to a locking nut (10), the outer wall of the locking nut (10) is threadedly connected to the inside of the inner rod (2), the connecting mechanism includes a screw rod (15), the top end of the screw rod (15) is fixedly connected to the inner rod (2 ), the outer wall of the inner rod (2) is threadedly connected to the inside of the tapered body (9), the outer ring of the bottom of the large outer circle of the soft claw (6) has four protrusions, which cooperate with the groove of the valve seat body (8) and rotate the valve seat body (8), the small outer circle at the bottom of the soft claw (6) is consistent with the inner hole size of the valve seat body (8), and is embossed on the outer side of the outer circle to increase the friction force when taking out the valve seat, and the bottom of the soft claw (6) is milled with four slots, which can form four petal-type non-metallic soft claws (6) when squeezed upward by the tapered body (9).

2. A valve seat assembly and disassembly tool according to claim 1, characterized in that: The outer wall of the tapered body (9) is fixedly connected to a connecting cylinder (21), and the inner walls of the tapered body (9) and the connecting cylinder (21) are both slidably connected to the outer wall of the inner rod (2).

3. The valve seat assembly and disassembly tool according to claim 1, characterized in that: The outer wall of the inner rod (2) is fixedly connected to the limiting ring (13), and the outer walls of the anti-slip pad (12) and the limiting ring (13) are both rotatably connected to the inner wall of the pressure rod (3).

4. The valve seat assembly and disassembly tool according to claim 1, characterized in that: The interior of the soft claw (6) is fixedly connected to a limiting cylinder (16), the inner wall of the limiting cylinder (16) is fixedly connected to a clamping block (17), and the outer wall of the clamping block (17) is slidably connected to the outer wall of the connecting cylinder (21).

5. The valve seat assembly and disassembly tool according to claim 4, characterized in that: The outer wall of the clamping block (17) is fixedly connected to a telescopic rod (18), the outer wall of the telescopic rod (18) is fixedly connected to the inner wall of the limiting cylinder (16), and a spring (19) is provided inside the limiting cylinder (16).

6. The valve seat assembly and disassembly tool according to claim 5, characterized in that: One end of the spring (19) is fixed to the clamping block (17), and the other end abuts against the inner wall of the limiting cylinder (16). The outer wall of the spring (19) is slidably connected to the outer wall of the telescopic rod (18).

7. The valve seat assembly and disassembly tool according to claim 4, characterized in that: The outer wall of the connecting cylinder (21) is provided with a clamping groove (14), and the outer wall of the clamping block (17) is slidably connected to the inner wall of the clamping groove (14).

8. The valve seat assembly and disassembly tool according to claim 2, characterized in that: A color ring column (20) is provided inside the inner rod (2), and when the tapered body (9) rises, it drives the color ring column (20) to slide in the inner rod (2).

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