CN117267382A - Valve capable of preventing water leakage - Google Patents

Abstract

The invention relates to the technical field of valves, and in particular to a leak-proof valve, which includes a shell. An inlet pipe and a water outlet pipe are fixedly connected to the outer side wall of the shell. A connector is fixedly installed on the top outer wall of the shell, and the top outer wall of the connector is fixed. A connecting pipe is fixedly connected, a hydraulic telescopic rod is installed inside the connecting pipe, a center rod is fixedly connected to one end of the hydraulic telescopic rod, a valve plug is fixedly connected to the bottom end of the center rod, and a valve plug is provided inside the shell near the middle position. Built-in blocks. By arranging a flushing mechanism, the present invention can flush the inner wall of the through hole when closing and opening the valve, so as to avoid contact and friction between the valve plug and the sediment adhering to the inner wall of the through hole, causing wear and tear, thereby avoiding leakage of the valve, and by setting The reset mechanism allows the valve plug to be flushed throughout the entire process of moving upward inside the through hole, preventing part of the inner wall of the through hole from being flushed when the valve is opened, affecting the flushing effect of sediment.

Description

A leak-proof valve

Technical field

The present invention relates to the technical field of valves, and in particular to a leak-proof valve.

Background technique

Valves are control components in fluid delivery systems. They have functions such as shutoff, regulation, diversion, prevention of reverse flow, pressure stabilization, diversion or overflow and pressure relief. Valves used in fluid control systems range from the simplest stop valves to extremely complex ones. Various valves used in automatic control systems have a wide range of varieties and specifications. Valves can be used to control the flow of various types of fluids such as air, water, steam, various corrosive media, mud, oil, liquid metal and radioactive media. .

When using a valve, the water flow inside it often contains sediment, and part of it adheres to the inner wall of the through hole. When controlling the cutoff or circulation of the water flow through the valve, it is necessary to use the valve plug to cooperate with the through hole to control the opening of the valve. In the closed state, during this process, the sediment adhered to the outer wall of the valve plug and the inner wall of the through hole are constantly in contact and friction, resulting in wear on the surface of the valve plug, and a gap between the worn part and the through hole, which in turn causes the valve to leak. Affects the opening and closing functions of the valve.

Contents of the invention

The purpose of the present invention is to propose a leak-proof valve to solve the problems in the background technology.

In order to achieve the above objects, the present invention adopts the following technical solutions:

A water leakage-proof valve, including a shell, the outer wall of the shell is fixedly connected with a water inlet pipe and a water outlet pipe, the top outer wall of the shell is fixedly installed with a connector, the top outer wall of the connector is fixedly connected with a connecting pipe, the connection A hydraulic telescopic rod is installed inside the pipe. One end of the hydraulic telescopic rod is fixedly connected to a center rod. The bottom end of the central rod is fixedly connected to a valve plug. There is a built-in block near the middle position inside the shell. The top outer wall of the built-in block A through hole is provided throughout, and baffles are fixedly installed on both sides of the built-in block. A flow chamber one and a flow chamber two are separated inside the shell by the baffle. A flushing mechanism for flushing sediment is provided inside the shell. , the outer wall of the central rod is provided with a reset mechanism for assisting in flushing sediment, a water storage tank 1 and a water storage tank 2 are provided inside the valve plug, the bottom end of the valve plug is fixedly connected with a connecting ring, and the upper and lower parts of the valve plug Several sets of flushing holes are provided through the end surfaces.

In the above-mentioned anti-leakage valve, the flushing mechanism includes a water storage tank. The water storage tank is fixedly installed inside the casing. An adjustment plug is inserted near the top of the water storage tank. The water storage tank Two regulating plugs are inserted near the bottom of the water tank.

In the above-mentioned anti-leakage valve, a spring is connected between the adjusting plug 1 and the adjusting plug 2, a U-shaped frame is inserted between the two ends of the water storage tank, and the two ends of the water storage tank are connected with each other. Two springs are connected between the two inner walls of the U-shaped frame.

In the above-mentioned anti-leakage valve, a long water inlet pipe is fixedly connected to the outer wall of the water storage tank. The end of the long water inlet pipe away from the water storage tank passes through the baffle and is arranged inside the circulation chamber. A water inlet head is fixedly connected to one end of the long water inlet pipe away from the water storage tank. A filter is fixedly installed at the bottom end of the water inlet head. A one-way valve is installed on the outer wall of the long water inlet pipe near the water inlet head.

In the above-mentioned anti-leakage valve, a telescopic hose is fixedly connected to the outer wall of the water storage tank and located below the long water inlet pipe. The outer side wall of the telescopic hose is fixedly connected to an end away from the water storage tank. Telescopic hose two, the end of the telescopic hose one away from the water storage tank is arranged inside the water storage bin one, the end of the telescopic hose two away from the water storage tank is arranged inside the water storage bin two, the telescopic hose one and the telescopic hose two One-way valve 2 is installed on the end of the outer wall near the valve plug.

In the above-mentioned anti-leakage valve, the reset mechanism includes two vertical plates and a slot. The two vertical plates are fixedly connected to the outer wall of the central rod. There are two sets of vertical plates inserted between the two vertical plates. An inserting block is inserted into the slot at one end away from the vertical plate. A spring is connected between one end of the inserting block and the inner wall of the slot.

In the above-mentioned anti-leakage valve, movable grooves are provided on both sides of the insert block, and a clamping block is inserted inside the movable slot. A spring is connected between one end of the clamping block and the inner wall of the chute. Fourth, two clamping slots are provided through the outer wall of the vertical plate, and the clamping slots fit with the clamping block.

In the above-mentioned anti-leakage valve, two sets of transverse grooves are provided on the outer wall of the U-shaped frame, and a chute is provided on the inner wall of the transverse groove, and a slider is inserted inside the chute. One end of the slider passes through the chute and is fixedly connected to the outer wall of the insert block. The outer wall of the slider is fixed with magnet two. The outer walls of the adjustment plug one and the second adjustment plug are both fixed with magnet one, and the two magnets are fixedly installed. The magnetic pole is opposite to the opposite side of the magnet.

Compared with existing technology, the advantages of this anti-leakage valve are:

1. When closing the valve, the adjusting plug 1 in the flushing mechanism moves downward inside the water storage tank, squeezing the water flow inside it, so that the water flows into the inside of the water storage tank 1 through the telescopic hose 1, and at the same time passes through the telescopic hose 2 It passes into the interior of the second water storage tank and is sprayed out through each group of flushing holes. At the same time, the valve plug gradually enters the inside of the through hole, so that the water flow sprayed from the inside of the flushing hole flushes the inner wall of the through hole and adheres to the inner wall of the through hole. The sediment is washed down. In the same way, when the valve is opened, the U-shaped frame can be driven to move upward, and the adjustment plug 2 can be driven to move upward. It also squeezes the water flow inside the water storage tank, causing the water flow to spray out from the inside of the flushing hole, and cleans the sediment. Flushing, thereby effectively avoiding the contact friction between the sediment adhered to the outer wall of the valve plug and the inner wall of the through hole when opening and closing the valve, causing wear and tear, thereby preventing the valve plug from leaking due to wear;

2. When the valve is closed and reopened, the bottom surface of the adjusting plug 1 is in close contact with the upper surface of the adjusting plug 2. The magnet 1 and the magnet 2 installed on the adjusting plug 1 attract each other, causing the magnet 2 to move closer to the magnet 1, driving the reset mechanism. The plug-in block shrinks toward the inside of the slot, and the spring three contracts, causing the block to move out of the movable slot. The vertical plate loses connection with the U-shaped frame, and under the action of the elastic force of the spring two, the U-shaped frame is driven upward to the initial position. , the insert block moves out of the slot under the action of the elastic force of the spring three, driving the card block to be clamped inside the slot at the uppermost end of the vertical plate, so that the U-shaped frame can be reset to the initial position in time, and the adjustment plug two is squeezed. Pressure, so that when the valve is opened, the water flow can be sprayed out from the inside of the flushing hole for flushing, so that the entire process of the valve plug moving inside the through hole can be flushed, to avoid that the inner wall of some through holes cannot be flushed, affecting the mud. The washing effect of sand;

3. Through the elastic force of spring one, the regulating plug one and the regulating plug two located inside the water storage tank can be separated from each other, causing suction to be generated inside the water storage tank, so that the water flow from the water inlet pipe into the inside of the shell can be matched with the water inlet head. The long water pipe flows into the inside of the water storage tank, so that the water flowing into the valve can be used to flush the sediment on the inner wall of the through hole;

To sum up, the present invention provides a flushing mechanism so that the inner wall of the through hole can be flushed when the valve is closed and opened, thereby preventing the valve plug from contacting and rubbing with the sediment adhered to the inner wall of the through hole, causing wear and tear, and thus preventing the valve from being damaged. Water leakage, and by setting up a reset mechanism, the entire process of the valve plug moving upward inside the through hole can be flushed, so as to avoid partial flushing of the inner wall of the through hole when the valve is opened, affecting the flushing effect of sediment.

Description of the drawings

Figure 1 is a schematic three-dimensional structural diagram of the present invention;

Figure 2 is a schematic diagram of the internal structure of the present invention;

Figure 3 is a schematic structural diagram of the flushing mechanism and housing in the present invention;

Figure 4 is an enlarged view of position A in Figure 3 according to the present invention;

Figure 5 is a partial structural schematic diagram of the present invention;

Figure 6 is an enlarged view of B in Figure 5 according to the present invention;

Figure 7 is a partial structural schematic diagram of the reset mechanism in the present invention;

Figure 8 is a cross-sectional view of the insertion block and the clamping block of the present invention.

In the picture: 1. Shell; 2. Water inlet pipe; 3. Water outlet pipe; 4. Connector; 5. Connecting pipe; 6. Hydraulic telescopic rod; 7. Center rod; 8. Valve plug; 9. Built-in block; 10. Baffle; 11. Flow chamber one; 12. Flow chamber two; 13. Connecting ring; 14. Water storage tank; 15. Adjustment plug one; 16. Adjustment plug two; 17. Spring one; 18. Long water inlet pipe ; 19. Water inlet head; 20. Filter; 21. Telescopic hose one; 22. U-shaped frame; 23. Spring two; 24. Flushing hole; 25. Water storage tank one; 26. Water storage tank two; 27. Magnet one; 28. Vertical plate; 29. Clamp; 30. Insert block; 31. Horizontal slot; 32. Slider; 33. Magnet 2; 34. Slot; 35. Spring 3; 36. Slide; 38. Washing mechanism; 39. Reset mechanism; 40. One-way valve; 41. Through hole; 42. Telescopic hose two; 43. Card slot; 44. Movable slot.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all the embodiments.

In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inner", " The orientation or positional relationship indicated by "outside" and so on is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation. Specific orientations of construction and operation are therefore not to be construed as limitations of the invention.

Referring to Figures 1 to 8, a leak-proof valve includes a shell 1. An inlet pipe 2 and an outlet pipe 3 are fixedly connected to the outer wall of the shell 1. A connector 4 is fixedly installed on the top outer wall of the shell 1. The top outer wall of the connector 4 is fixed. A connecting pipe 5 is connected, and a hydraulic telescopic rod 6 is installed inside the connecting pipe 5. One end of the hydraulic telescopic rod 6 is fixedly connected to a center rod 7, and the bottom end of the center rod 7 is fixedly connected to a valve plug 8. A built-in valve plug 8 is fixedly connected to the bottom of the center rod 7. The inside of the shell 1 is provided with a built-in valve near the middle position. Block 9, the top outer wall of the built-in block 9 is penetrated with a through hole 41, and baffles 10 are fixedly installed on both sides of the built-in block 9. The inside of the shell 1 is divided into a flow chamber 11 and a flow chamber 2 12 by the baffle 10. The shell 1 A flushing mechanism 38 for flushing sediment is provided inside, and a reset mechanism 39 for assisting flushing of sediment is arranged on the outer wall of the center rod 7. A water storage bin 25 and a water storage bin 26 are provided inside the valve plug 8. The bottom end of the valve plug 8 is fixedly connected. There is a connecting ring 13, and a plurality of sets of flushing holes 24 are drilled through the upper and lower surfaces of the valve plug 8.

The flushing mechanism 38 includes a water storage tank 14. The water storage tank 14 is fixedly installed inside the housing 1. An adjustment plug 15 is inserted near the top of the water storage tank 14. An adjustment plug 2 is inserted near the bottom of the water storage tank 14. 16. A spring 17 is connected between the adjusting plug 15 and the adjusting plug 2 16. A U-shaped frame 22 is inserted between the two ends of the water storage tank 14. Between the two ends of the water storage tank 14 and the inner walls of the U-shaped frame 22 Spring two 23 are connected to each other, and a long water inlet pipe 18 is fixedly connected to the outer wall of the water storage tank 14. One end of the long water inlet pipe 18 away from the water storage tank 14 passes through the baffle 10 and is arranged inside the circulation chamber 11. The long water inlet pipe 18 The end of the pipe 18 away from the water storage tank 14 is fixedly connected to a water inlet head 19. A filter 20 is fixedly installed at the bottom end of the water inlet head 19. The outer wall of the long water inlet pipe 18 is equipped with a one-way valve 40 at one end close to the water inlet head 19. .

Through the elastic force of spring one 17, the adjusting plug 15 and the adjusting plug 2 16 located inside the water storage tank 14 can be separated from each other, so that a suction force is generated inside the water storage tank 14, so that the water flow from the water inlet pipe 2 into the inside of the housing 1 can pass through The water inlet head 19 cooperates with the long water inlet pipe 18 to flow into the water storage tank 14. The sediment in the water flow can be filtered out through the filter screen 20. The one-way valve 40 can prevent the water flow from passing through the water inlet from the inside of the water storage tank 14. The long tube 18 flows out.

A telescopic hose 21 is fixedly connected to the outer wall of the water storage tank 14 and is located below the long water inlet pipe 18. A telescopic hose 21 is fixedly connected to the outer wall of the telescopic hose 14 away from the water storage tank 14. A telescopic hose 42 is fixedly connected to the outer wall of the telescopic hose 14. The end of 21 away from the water storage tank 14 is set inside the water storage silo 1 25 , the end of the telescopic hose 2 42 away from the water storage tank 14 is set inside the water storage silo 2 26 , the end of the outer wall of the telescopic hose one 21 and the telescopic hose two 42 is close to the valve plug 8 Both are equipped with one-way valve 2.

Squeeze the water flow inside it, so that the water flows into the inside of the water storage tank 25 through the telescopic hose 21, and at the same time flows into the inside of the water storage tank 26 through the telescopic hose 2 42, and is sprayed out through each group of flushing holes 24. At the same time, the valve The plug 8 gradually enters the inside of the through hole 41 , so that the water flow sprayed from the inside of the flushing hole 24 flushes the inner wall of the through hole 41 .

The one-way valve two can prevent the water inside the first water storage tank 25 and the second water storage tank 26 from flowing out from the inside of the first telescopic hose 21 and the second telescopic hose 42.

When in use, the valve is installed in a pipeline, in which the water flow in the pipeline flows into the inside of the housing 1 through the water inlet pipe 2, and flows out from the inside of the outlet pipe 3 through the flow chamber 11 and the flow chamber 2 12, in which the water flows through the hydraulic telescopic rod. 6 drives the center rod 7 to move up and down, which can drive the valve plug 8 to move up and down. When the valve plug 8 moves out from the inside of the through hole 41, it is the open state of the valve. On the contrary, when the valve plug 8 enters the inside of the through hole 41 to fill it. , which is the closed state of the valve. When closing the valve, the center rod 7 moves downward, driving the U-shaped frame 22 to move downward, thereby driving the adjusting plug 15 to move downward again inside the water storage tank 14, squeezing The water flow inside it causes the water flow to pass into the interior of the water storage bin 25 through the telescopic hose 21, and at the same time pass into the interior of the water storage bin 26 through the telescopic hose 2 42, and spray out through each group of flushing holes 24. At the same time, the valve plug 8 Gradually enter the inside of the through hole 41, so that the water flow sprayed from the inside of the flushing hole 24 flushes the inner wall of the through hole 41, flushing away the sediment adhered to the inner wall, and preventing the outer wall of the valve plug 8 from contacting the inner side of the through hole 41 The sediment adhered to the wall contacts and rubs, causing wear and tear. Similarly, when the valve is opened, the U-shaped frame 22 can be driven to move upward, and the adjustment plug 216 can be driven to move upward, which also squeezes the water flow inside the water storage tank 14, causing the water flow to flow from flushing. The inside of the hole 24 is ejected to flush the sediment.

The reset mechanism 39 includes two vertical plates 28 and a slot 34. The two vertical plates 28 are fixedly connected to the outer walls of the center pole 7. An insert block 30 is inserted between the two sets of vertical plates 28, and the insert block 30 is away from the vertical plates. One end of 28 is inserted inside the slot 34, and a spring 35 is connected between one end of the insert block 30 and the inner wall of the slot 34.

The insert block 30 and the vertical plate 28 serve to connect the positions between the center rod 7 and the U-shaped frame 22 .

Movable slots 44 are provided on both sides of the insertion block 30. A clamping block 29 is inserted inside the movable slot 44. A spring is connected between one end of the clamping block 29 and the inner wall of the chute 36. Two springs are provided on the outer wall of the vertical plate 28. There is a card slot 43, and the card slot 43 fits with the card block 29.

When the insert block 30 moves, the clamp block 29 moves with the insert block 30, and its outer wall moves along the inner wall of the movable slot 44, and gradually shrinks into the inside of the movable slot 44. The spring four is compressed, and the subsequent elastic force of the spring four can drive the clamp block 29 Move out from inside the movable slot 44 again.

Two sets of transverse grooves 31 are formed on the outer wall of the U-shaped frame 22. A chute 36 is formed on the inner wall of the transverse groove 31. A slide block 32 is inserted inside the chute 36. One end of the slide block 32 passes through the chute 36 and the insertion block 30. The outer walls are fixedly connected. The slider 32 has a magnet two 33 fixedly installed on the outer wall. The adjusting plug 15 and the adjusting plug 2 16 both have a magnet 27 fixedly installed on the outer side walls, and the magnets 2 33 and 27 have opposite magnetic poles.

After closing the valve, when opening it again, the U-shaped frame 22 is in a state of squeezing the adjusting plug 15. The bottom surface of the adjusting plug 15 is in close contact with the upper surface of the adjusting plug 2 16. The magnet installed on the outer wall of the adjusting plug 15 Magnet one 27 and magnet two 33 attract each other, causing magnet two 33 to move closer to magnet one 27, so that the slide block 32 inserted inside the transverse slot 31 moves along the chute 36 towards the direction close to the water storage tank 14, thereby driving the insert block 30 shrinks toward the inside of the slot 34, and the spring three 35 contracts, so that the block 29 moves out from the inside of the movable slot 44. At this time, the vertical plate 28 loses connection with the U-shaped frame 22, and under the action of the elastic force of the spring two 23, the U-shaped frame 22 is driven. The frame 22 moves upward to the initial position, and the insert block 30 moves out of the slot 34 under the elastic force of the spring 35, driving the block 29 to move to the inside of the two sets of vertical plates 28, and is clamped on the top of the vertical plates 28. Inside the slot 43 at the end, so that the U-shaped frame 22 can be reset to the initial position in time, and the adjusting plug 16 is squeezed, so that when the valve is opened, the water flow can be sprayed out from the inside of the flushing hole 24 for flushing, so that The entire process of the valve plug 8 moving inside the through hole 41 can be flushed, so as to prevent the inner wall of the through hole 41 from not being flushed and affecting the flushing effect of sediment.

It should be further explained that the above-mentioned fixed connection, unless otherwise explicitly stipulated and limited, should be understood in a broad sense. For example, it may be welding, gluing, or one-piece molding and other common means well known to those skilled in the art.

The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person familiar with the technical field can, within the technical scope disclosed in the present invention, implement the technical solutions of the present invention. Equivalent substitutions or changes of the inventive concept thereof shall be included in the protection scope of the present invention.

Claims (8)

1. The utility model provides a valve of leak protection water, its characterized in that, including shell (1), shell (1) lateral wall fixedly connected with inlet tube (2) and outlet pipe (3), shell (1) top outer wall fixed mounting has connector (4), connector (4) top outer wall fixedly connected with connecting pipe (5), connecting pipe (5) internally mounted has hydraulic telescoping rod (6), hydraulic telescoping rod (6) one end fixedly connected with center pole (7), center pole (7) bottom fixedly connected with valve plug (8), shell (1) inside is close to intermediate position and is provided with built-in piece (9), built-in piece (9) top outer wall runs through and has seted up through-hole (41), built-in piece (9) both sides wall equal fixed mounting has baffle (10), the inside circulation chamber (11) and the circulation chamber second (12) of having separated through baffle (10) of shell (1), shell (1) inside is provided with the flushing mechanism (38) that are used for washing silt, center pole (7) lateral wall is provided with and is used for supplementary center pole (39), valve plug (8) inside (8) are close to intermediate position and are provided with built-in piece (25) and are connected with water storage ring (13), the upper end surface and the lower end surface of the valve plug (8) are provided with a plurality of groups of flushing holes (24) in a penetrating way.

2. The water leakage preventing valve according to claim 1, wherein: the flushing mechanism (38) comprises a water storage tank (14), the water storage tank (14) is fixedly arranged inside the shell (1), an adjusting plug I (15) is inserted in the water storage tank (14) near the top end, and an adjusting plug II (16) is inserted in the water storage tank (14) near the bottom end.

3. The water leakage preventing valve according to claim 2, wherein: the water storage tank is characterized in that a first spring (17) is connected between the first adjusting plug (15) and the second adjusting plug (16), a U-shaped frame (22) is inserted between two ends of the water storage tank (14), and a second spring (23) is connected between two ends of the water storage tank (14) and two inner side walls of the U-shaped frame (22).

4. The water leakage preventing valve according to claim 2, wherein: the water storage tank is characterized in that the outer side wall of the water storage tank (14) is fixedly connected with a water inlet long pipe (18), one end of the water inlet long pipe (18), far away from the water storage tank (14), passes through the baffle (10) and is arranged inside the first circulation cavity (11), one end of the water inlet long pipe (18), far away from the water storage tank (14), is fixedly connected with a water inlet head (19), the bottom end of the water inlet head (19) is fixedly provided with a filter screen (20), and one end, close to the water inlet head (19), of the outer side wall of the water inlet long pipe (18) is provided with a one-way valve (40).

5. The water leakage preventing valve according to claim 4, wherein: the water storage tank is characterized in that a first telescopic hose (21) is fixedly connected to the outer side wall of the water storage tank (14) and located below the water inlet long pipe (18), a second telescopic hose (42) is fixedly connected to the outer side wall of the first telescopic hose (21) away from one end of the water storage tank (14), one end of the first telescopic hose (21) away from the water storage tank is arranged inside the first water storage bin (25), one end of the second telescopic hose (42) away from the water storage tank (14) is arranged inside the second water storage bin (26), and a second check valve is arranged on the outer side wall of the first telescopic hose (21) and the outer side wall of the second telescopic hose (42) close to one end of the valve plug (8).

6. A water leakage prevention valve according to claim 3, wherein: the reset mechanism (39) comprises two vertical plates (28) and a slot (34), wherein the two vertical plates (28) are fixedly connected to the outer side wall of the central rod (7), an inserting block (30) is inserted between the two vertical plates (28), one end, far away from the vertical plates (28), of each inserting block (30) is inserted into the slot (34), and a spring III (35) is connected between one end of each inserting block (30) and the inner side wall of the slot (34).

7. The water leakage preventing valve according to claim 6, wherein: the movable grooves (44) are formed in the two side walls of the inserting block (30), the clamping blocks (29) are inserted into the movable grooves (44), the springs IV are connected between one end of each clamping block (29) and the inner side wall of each sliding groove (36), the two clamping grooves (43) are formed in the outer side wall of each vertical plate (28) in a penetrating mode, and the clamping grooves (43) are matched with the clamping blocks (29).

8. The water leakage preventing valve according to claim 7, wherein: two groups of transverse grooves (31) are formed in the outer side wall of the U-shaped frame (22) in a penetrating mode, sliding grooves (36) are formed in the inner side walls of the transverse grooves (31), sliding blocks (32) are inserted into the sliding grooves (36), one ends of the sliding blocks (32) penetrate through the sliding grooves (36) and are fixedly connected with the outer side walls of the inserting blocks (30), two magnets (33) are fixedly arranged on the outer side walls of the sliding blocks (32), one magnet (27) is fixedly arranged on the outer side walls of the first adjusting plug (15) and the second adjusting plug (16), and magnetic poles of the two magnets (33) are opposite to those of the opposite sides of the first magnet (27).