CN210119009U

CN210119009U - Condensation waste heat pressure-bearing hot water boiler

Info

Publication number: CN210119009U
Application number: CN201920930933.9U
Authority: CN
Inventors: 马凯勤; 郑大勇
Original assignee: Jiangsu Kono Boiler Co ltd
Current assignee: Jiangsu Kono Boiler Co ltd
Priority date: 2019-06-19
Filing date: 2019-06-19
Publication date: 2020-02-28
Anticipated expiration: 2029-06-19

Abstract

The utility model discloses a condensation waste heat pressure-bearing hot water boiler, which comprises a shell, wherein water is filled in the shell, a furnace bladder is arranged in the shell, one end of the shell is provided with a burner, one end of the furnace bladder, which is opposite to the burner, is provided with a recombustion chamber, the recombustion chamber is communicated with a heat exchange smoke tube, the heat exchange smoke tube is communicated with an air preheater, the shell is communicated with a condensation box, the condensation box is internally provided with a condensation pipe, the condensation box is communicated with a smoke exhaust pipe, the shell is communicated with a water outlet joint, the upper end of the shell is provided with an alarm device, the alarm device comprises an outer pipe which is fixed on the shell and is communicated with an inner cavity of the shell; the outer side of the insulating rod extending out of the shell is contacted with an electrode block, and the surfaces opposite to the electrode block are respectively and fixedly provided with a reset pressure spring; the two electrode blocks are respectively and electrically connected with a lead, and an alarm and a power supply are connected on the leads in series. The utility model discloses have the effect that the pressure of control boiler sent an alarm.

Description

Condensation waste heat pressure-bearing hot water boiler

Technical Field

The utility model belongs to the technical field of steam boiler and specifically relates to a condensation waste heat pressure-bearing boiler is related to.

Background

With the development of national economy, the exploitation of large natural gas fields and the supporting facilities thereof are built and put into operation one after another. In order to improve living and investment environments and meet the requirements of environmental protection, energy conservation and consumption reduction, the requirements of various gas boilers are continuously increased in recent years. Meanwhile, with the continuous development of high-efficiency, environment-friendly and energy-saving boiler design, manufacturing technology and novel materials, the condensing gas boiler is gradually mature and universal in structure. In a traditional boiler, the exhaust gas temperature is generally 160-250 ℃, the water vapor in the exhaust gas is still in an overheated state and cannot be condensed into liquid water to release latent heat of vaporization. As is well known, the thermal efficiency of a boiler is calculated by the lower heating value of fuel, and the heat loss of latent heat of vaporization in the upper heating value of fuel is not considered. Therefore, the heat efficiency of the traditional boiler can only reach 87 to 91 percent generally.

The Chinese invention patent application publication No. CN109058964A discloses a pressure-bearing steam boiler, which comprises a boiler shell barrel, wherein a boiler shell sealing head is connected above the boiler shell barrel, a circular lower foot ring plate is arranged at the lower end of the boiler shell barrel, a safety valve, an inflation tube, a pressure gauge and an air outlet joint are arranged on the boiler shell sealing head, a coal hand, a liquid level indicator and a water temperature gauge are arranged at the upper part of the boiler shell barrel, an upper boiler door is arranged above the coal hand, a fire observation air inlet is arranged in the middle of the boiler shell barrel, an air inlet and a water inlet joint are arranged at one side of the lower part of the boiler shell barrel, and a lower boiler door and a coal. The novel smoke-free air-conditioning system has the advantages of reasonable design, safety, reliability, excellent ventilation, tight closing, full combustion, high heat utilization rate, large heating area, long heat exchange distance, low smoke exhaust temperature and no need of special equipment for removing smoke dust.

The above prior art solutions have the following drawbacks: when the existing steam boiler works, a certain pressure exists in the boiler, and when the pressure in the boiler is lower than a set pressure which is not met, although electronic equipment is used for detecting and alarming, the electronic equipment monitors and has a high failure rate.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a condensation waste heat pressure-bearing boiler, it has the effect of monitoring boiler internal pressure and sending an alarm.

The above technical purpose of the present invention can be achieved by the following technical solutions:

a condensation waste heat pressure-bearing hot water boiler comprises a shell, wherein water is filled in the shell, a furnace liner is arranged in the shell, a combustor located at one end of the furnace liner is arranged on the shell, a combustion chamber communicated with an inner cavity of the furnace liner is arranged at one end of the furnace liner opposite to the combustor, a heat exchange smoke pipe is communicated with the combustion chamber, an air preheater is communicated with the heat exchange smoke pipe, a condensing box communicated with an outlet end of the air preheater is communicated with the shell, a condensing pipe is arranged in the condensing box, a smoke exhaust pipe is communicated with the condensing box, a water outlet connector is communicated with the shell, an alarm device is arranged at the upper end of the shell and comprises an outer pipe which is fixed on the shell and communicated with the inner cavity of the shell, a sliding block is arranged in the outer pipe in a sleeved mode, an insulating rod is fixedly arranged on the sliding block, a fixing ring is arranged outside the insulating rod, and the fixing, the insulating rod is sleeved with an alarm pressure spring positioned between the fixed ring and the sliding block;

the outer side of the insulating rod extending out of the shell is contacted with two electrode blocks, the two electrode blocks are positioned on two sides of the central line of the insulating rod, notches are respectively formed in the opposite surfaces of one ends of the two electrode blocks, facing the sliding block, opposite surfaces of the two electrode blocks, respectively, resetting pressure springs are fixedly arranged, the axes of the two resetting pressure springs are the same, a resetting plate fixed on the outer pipe is fixedly arranged at one end, facing away from the electrode blocks, of the resetting pressure springs, and the resetting pressure springs push the two opposite surfaces of the electrode blocks to be abutted against and compressed with the insulating rod;

when the insulating rod moves back to the electrode blocks under the action of the sliding block and moves out of the space between the two electrode blocks, the electrode blocks move relatively under the action of the reset pressure spring, and the two electrode blocks are in contact with each other and are pressed tightly;

the two electrode blocks are respectively and electrically connected with a lead, and an alarm and a power supply are connected on the leads in series.

By adopting the technical scheme, the burner sprays a mixture of fuel and air into the furnace pipe for combustion, the combusted waste gas enters the combustion chamber for further combustion, the furnace pipe and the combustion chamber heat water in the shell, the waste gas in the combustion chamber enters the heat exchange smoke pipe, the heat exchange smoke pipe further heats the water in the shell, the waste gas in the heat exchange smoke pipe flows into the air preheater, the air preheater heats the air mixed with the fuel, the waste gas flowing through the air preheater enters the condensing box, the waste gas in the condensing box heats the condensing pipe, the waste gas heats clean water in the condensing pipe, the condensing pipe heats the water flowing into the shell before heating, and the waste gas is discharged from the smoke discharge pipe; the steam with pressure in the shell is discharged from the water outlet joint for users to use;

when pressure in the casing is not enough, the alarm pressure spring promotes the sliding block and removes to solid fixed ring direction dorsad, and the sliding block drives the insulator spindle and removes to make the insulator spindle shift out from between two electrode blocks, and the pressure spring that resets this moment promotes two electrode block relative motion, and two electrode block conflict relatively compress tightly, and the circuit switch-on at power place this moment, power supply to the siren power supply, and the siren sends out the police dispatch newspaper to remind the staff.

The utility model discloses further set up to: the side of the electrode block back sliding block is respectively and fixedly provided with a metal elastic sheet, the metal elastic sheets are arranged at intervals along the central line direction of the insulating rod, the insulating rod is provided with projections on the two metal elastic sheets along the self axis direction, and the insulating rod can push the two metal elastic sheets back to the metal elastic sheets and tightly press the mutual conflict of one end connected with the reset plate when moving along the self axis direction and towards the metal elastic sheets.

Through adopting above-mentioned technical scheme, when pressure in the casing was too big, steam promotion sliding block in the casing moved towards solid fixed ring direction, and the sliding block drives the insulator spindle and removes when removing, and the insulator spindle can be contradicted in metal shrapnel to the one end of sliding block dorsad, and when metal shrapnel contradicted each other and compressed tightly, power place circuit switch-on, the siren can send out the police dispatch newspaper equally this moment, reminds the workman.

The utility model discloses further set up to: the outer tube is provided with a pressure relief hole, and the pressure relief hole is positioned at one end of the side surface of the outer tube, which is close to the fixing ring.

Through adopting above-mentioned technical scheme, after the sliding block moved to the siren and sounded towards solid fixed ring direction, if pressure in the casing continued the increase, the sliding block continued to move towards solid fixed ring direction, until the casing inner chamber passes through pressure release hole and atmosphere intercommunication, realized the pressure release of pressure release hole to the casing inner chamber.

The utility model discloses further set up to: the sealing groove has been seted up to the sliding block side, the cover is equipped with the sealing washer of embedding in the sealing groove on the sliding block, the sealing washer compresses tightly with the outer tube lateral surface.

Through adopting above-mentioned technical scheme, setting up of sealing washer increases the sealed effect between sliding block and the outer tube.

The utility model discloses further set up to: the alarm comprises a buzzer and a flashlight.

Through adopting above-mentioned technical scheme, buzzer and flash light combined action can ensure that the siren plays the alarm effect under noisy, dark environment.

The utility model discloses further set up to: the insulating rod is fixedly provided with a limiting ring, and the limiting ring is positioned on one side of the fixing ring, which faces away from the sliding block.

Through adopting above-mentioned technical scheme, the spacing ring can prevent to slide and drive the insulator spindle and get into in the outer tube completely when solid fixed ring removes dorsad, and when the insulator spindle removed to spacing ring and electrode block contact, the spacing ring can restrict the removal of insulator spindle, the insulator spindle's of being convenient for use.

The utility model discloses further set up to: the notch is an arc-shaped opening.

Through adopting above-mentioned technical scheme, the setting of arc mouth can be convenient for the insulator spindle to insert between two electrode blocks.

The utility model discloses further set up to: the one end of insulating rod back to the sliding block sets firmly the round platform, the main aspects of round platform and the terminal surface coincidence of insulating rod.

Through adopting above-mentioned technical scheme, the setting of round platform can be convenient for the insulator spindle to insert between two electrode blocks.

To sum up, the beneficial effects of the utility model are that:

1. the combustor sprays a mixture of fuel and air into the furnace container to combust, the combusted waste gas enters the combustion chamber to be further combusted, the furnace container and the combustion chamber heat water in the shell, the waste gas in the combustion chamber enters the heat exchange smoke tube, the heat exchange smoke tube further heats the water in the shell, the waste gas in the heat exchange smoke tube flows into the air preheater, the air preheater heats the air mixed with the fuel, the waste gas passing through the air preheater flows into the condensing box, the waste gas in the condensing box heats the condensing tube, the waste gas heats clean water in the condensing tube, the condensing tube heats the water flowing into the shell before being extracted, and the waste gas is discharged from the smoke exhaust tube; the steam with pressure in the shell is discharged from the water outlet joint for users to use; when the pressure in the shell is insufficient, the alarm compression spring pushes the sliding block to move in the direction opposite to the direction of the fixing ring, the sliding block drives the insulating rod to move so that the insulating rod is moved out of the space between the two electrode blocks, the reset compression spring pushes the two electrode blocks to move relatively, the two electrode blocks are pressed against each other, a circuit where the power supply is located is switched on, the power supply supplies power to the alarm, and the alarm gives an alarm to remind a worker;

2. when the pressure in the shell is overlarge, steam in the shell pushes the sliding block to move towards the direction of the fixing ring, the sliding block drives the insulating rod to move when moving, one end, back to the sliding block, of the insulating rod can abut against the metal elastic pieces, when the metal elastic pieces abut against each other and are compressed, a circuit where a power supply is located is connected, and at the moment, the alarm can give an alarm to remind workers;

3. when the sliding block moves to the rear of the sounding of the alarm towards the direction of the fixed ring, if the pressure in the shell continues to increase, the sliding block continues to move towards the direction of the fixed ring until the inner cavity of the shell is communicated with the atmosphere through the pressure relief hole, so that the pressure relief of the inner cavity of the shell by the pressure relief hole is realized.

Drawings

FIG. 1 is a schematic view of the overall structure of the embodiment;

fig. 2 is an enlarged view of a portion a in fig. 1.

In the figure, 11, the housing; 12. a furnace pipe; 13. a burner; 14. a flashback chamber; 15. a heat exchange smoke pipe; 16. a water outlet joint; 17. repairing the joint; 18. a blow-off pipe; 2. an air preheater; 3. a condenser tank; 31. a condenser tube; 32. a smoke exhaust pipe; 4. an air intake fan; 41. a muffler; 5. an alarm device; 51. an outer tube; 511. a pressure relief vent; 52. a slider; 521. a seal ring; 53. an insulating rod; 531. a circular truncated cone; 532. a limiting ring; 54. a fixing ring; 55. an alarm compression spring; 56. an electrode block; 561. a notch; 57. resetting the pressure spring; 58. a reset plate; 59. a metal spring sheet; 61. a wire; 62. a power source; 63. a buzzer; 64. a flash lamp.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Example one

Referring to fig. 1, for the utility model discloses a condensation waste heat pressure-bearing boiler, casing 11 including cylindrical cavity structure, 11 intussuseptions of casing are filled with water, are provided with corrugated furnace pipe 12 in the

casing

11, and 11 one end of casing is provided with the combustor 13 of sending into fuel and air in the furnace pipe 12, and the one end of furnace pipe 12 dorsad combustor 13 is provided with the back-fire room 14 with 12 inner chambers of furnace pipe intercommunication, and back-

fire room

14 and 12 inner chambers of furnace pipe intercommunication, back-fire room 14 are the cylindrical lid that the internal diameter is greater than 12 internal diameters of furnace pipe. An overhaul connector 17 is arranged at one end of the shell 11, which is opposite to the burner 13, a sewage discharge pipe 18 communicated with the inner cavity of the shell 11 is welded at the bottom end of the shell 11, a valve for controlling the opening and closing of the sewage discharge pipe 18 is arranged on the sewage discharge pipe 18, and a safety valve communicated with the inner cavity of the shell 11 is fixed at the upper end of the shell 11.

Referring to fig. 1, the recombustion chamber 14 is communicated with a plurality of heat exchange smoke pipes 15, the heat exchange smoke pipes 15 are arranged at intervals along the surface of the recombustion chamber 14 facing the burner 13, the axis of each heat exchange circular pipe is parallel to the axis of the furnace pipe 12, and one end of each heat exchange smoke pipe 15, which is back to the recombustion chamber 14, is communicated with the air preheater 2. The air preheater 2 is connected with an air inlet fan 4, the air inlet fan 4 sends fresh air into the air preheater 2, and the air inlet fan 4 is provided with a silencer 41.

Referring to fig. 1, a condensing box 3 communicated with an outlet end of an air preheater 2 is communicated with a shell 11, a condensing pipe 31 is arranged in the condensing box 3, an inlet end of the condensing pipe 31 is connected to a water return pipeline, an outlet end of the condensing pipe 31 sends water into the shell 11, a smoke exhaust pipe 32 is communicated with the condensing box 3, and a water outlet joint 16 communicated with an inner cavity of the shell 11 is fixed on the shell 11.

Referring to fig. 1, the alarm device 5 is provided at the upper end of the housing 11.

Referring to fig. 2, the alarm device 5 includes the outer tube 51 that is fixed in the casing 11 and communicates with the inner chamber of the casing 11, the outer tube 51 is a circular tube of L type, the outer tube 51 includes the standpipe fixed with the casing 11 and the horizontal pipe fixed with the standpipe and communicating, the inner chamber of the outer tube 51 is sleeved with the cylindrical sliding block 52 sliding along the inner side of the outer tube 51, the side of the sliding block 52 is provided with a sealing groove, the sliding block 52 is sleeved with the sealing ring 521 embedded in the sealing groove, and the sealing ring 521 is compressed with the outer side.

Referring to fig. 2, an insulating rod 53 with a diameter smaller than that of the sliding block is fixedly arranged on the sliding block 52, a circular truncated cone 531 is integrally arranged at one end of the insulating rod 53, which is back to the sliding block 52, and the large end of the circular truncated cone 531 is superposed with the end surface of the insulating rod 53. The insulating rod 53 is sleeved with a fixing ring 54, and the fixing ring 54 is fixed at one end of the outer tube 51 extending out of the shell 11. The insulation rod 53 is fixedly provided with a limit ring 532, and the limit ring 532 is positioned on one side of the fixed ring 54 opposite to the sliding block 52.

Referring to fig. 2, the outer tube 51 is provided with a pressure relief hole 511, and the pressure relief hole 511 is located at one end of the side surface of the outer tube 51 close to the fixing ring 54.

Referring to fig. 2, an alarm compression spring 55 located between the fixed ring 54 and the slide block 52 is sleeved on the insulating rod 53, and the alarm compression spring 55 is in a compressed state;

referring to fig. 2, the insulating rod 53 extends out of the housing 11 and contacts with the electrode blocks 56, two electrode blocks 56 are disposed on two sides of the center line of the insulating rod 53, notches 561 are respectively disposed on opposite surfaces of one ends of the two electrode blocks 56 facing the sliding block 52, the notches 561 are arc-shaped openings, and the arc-shaped openings formed by the two opposite electrode blocks 56 are spherical grooves with a radius equal to the diameter of the insulating rod 53. The surface that the electrode block 56 carried on the back has set firmly the pressure spring 57 that resets respectively, and two pressure springs 57 that reset's axis is the same, and the one end that the pressure spring 57 that resets back to electrode block 56 has set firmly the board 58 that resets that is fixed in on outer tube 51, and the board 58 that resets is the L template, and the pressure spring 57 that resets can promote two surfaces that electrode block 56 is relative contradict with insulator spindle 53 side and compress tightly.

Referring to fig. 2, when the insulating rod 53 is moved away from the electrode blocks 56 by the action of the sliding block 52 and moves out of between the two electrode blocks 56, the electrode blocks 56 move relatively by the action of the return compression spring 57, and the two electrode blocks 56 are pressed in contact with each other;

referring to fig. 2, the electrode block 56 is respectively and fixedly provided with a metal spring piece 59, the metal spring pieces 59 are L-shaped pieces with opposite openings and facing the electrode block 56, the metal spring pieces 59 are located on one side of the electrode block 56 facing away from the sliding block 52, the two metal spring pieces 59 are arranged at intervals along the central line direction of the insulating rod 53, the insulating rod 53 has projections on the two metal spring pieces 59 along the self axis direction, and the insulating rod 53 can push the two metal spring pieces 59 to press the end, connected with the reset plate 58, of the two metal spring pieces 59 against each other when moving along the self axis direction and facing the direction of the metal spring pieces 59.

Referring to fig. 2, two electrode blocks 56 are electrically connected with a lead 61, and a warning device and a power supply 62 are connected in series on the lead 61, wherein the warning device comprises a buzzer 63 and a flashing lamp 64.

The implementation principle of the above embodiment is as follows:

the combustor 13 injects a mixture of fuel and air into the furnace pipe 12 for combustion, the combusted waste gas enters the combustion chamber 14 for further combustion, and the furnace pipe 12 and the combustion chamber 14 heat water in the shell 11; the gas in the furnace container 12 enters the combustion chamber 14 and then continues to be combusted, the waste gas in the combustion chamber 14 enters the heat exchange smoke tube 15, the heat exchange smoke tube 15 further heats the water in the shell 11, the waste gas in the heat exchange smoke tube 15 flows into the air preheater 2, the air preheater 2 heats the air mixed with the fuel, the waste gas passing through the air preheater 2 flows into the condensing box 3, the waste gas in the condensing box 3 heats the condensing pipe 31, the waste gas heats the clear water in the condensing pipe 31, the condensing pipe 31 heats the water flowing into the shell 11 before being heated, and the waste gas is discharged from the smoke discharge pipe 32; the steam with pressure in the shell 11 is discharged from the water outlet joint 16 for users to use;

when the pressure in the shell 11 is insufficient, the alarm pressure spring 55 pushes the sliding block 52 to move back to the direction of the fixed ring 54, the sliding block 52 drives the insulating rod 53 to move so that the insulating rod 53 is moved out of the two electrode blocks 56, the reset pressure spring 57 pushes the two electrode blocks 56 to move relatively, the two electrode blocks 56 are pressed against each other relatively, the circuit where the power source 62 is located is switched on, the power source 62 supplies power to the alarm, and the alarm gives an alarm so as to remind a worker.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications to the present embodiment without inventive contribution as required after reading the present specification, but all of them are protected by patent laws within the scope of the claims of the present invention.

Claims

1. A condensation waste heat pressure-bearing hot water boiler comprises a shell (11), wherein water is filled in the shell (11), a furnace pipe (12) is arranged in the shell (11), a burner (13) positioned at one end of the furnace pipe (12) is arranged on the shell (11), one end of the furnace pipe (12) back to the burner (13) is provided with a back combustion chamber (14) communicated with the inner cavity of the furnace pipe (12), the combustion chamber (14) is communicated with a heat exchange smoke pipe (15), the heat exchange smoke pipe (15) is communicated with an air preheater (2), a condensing box (3) communicated with the outlet end of the air preheater (2) is communicated with the shell (11), a condensing pipe (31) is arranged in the condensing box (3), a smoke exhaust pipe (32) is communicated with the condensing box (3), the casing (11) is provided with a water outlet joint (16) in a communicated manner, and is characterized in that: the alarm device (5) is arranged at the upper end of the shell (11), the alarm device (5) comprises an outer tube (51) which is fixed on the shell (11) and communicated with the inner cavity of the shell (11), a sliding block (52) is sleeved in the outer tube (51), an insulating rod (53) is fixedly arranged on the sliding block (52), a fixing ring (54) is sleeved outside the insulating rod (53), the fixing ring (54) is fixed at one end, extending out of the shell (11), of the outer tube (51), and an alarm pressure spring (55) located between the fixing ring (54) and the sliding block (52) is sleeved on the insulating rod (53);

the outer side of the insulating rod (53) extending out of the shell (11) is contacted with electrode blocks (56), two electrode blocks (56) are arranged on two sides of the center line of the insulating rod (53), one ends of the two electrode blocks (56) facing the sliding block (52) and opposite surfaces of the two electrode blocks are respectively provided with a notch (561), the opposite surfaces of the electrode blocks (56) are respectively and fixedly provided with a reset pressure spring (57), the axes of the two reset pressure springs (57) are the same, one end of the reset pressure spring (57) opposite to the electrode block (56) is fixedly provided with a reset plate (58) fixed on the outer tube (51), and the reset pressure spring (57) pushes the two opposite surfaces of the electrode block (56) to be abutted against and compressed by the insulating rod (53);

when the insulating rod (53) moves back to the electrode blocks (56) under the action of the sliding block (52) and moves out of the space between the two electrode blocks (56), the electrode blocks (56) move relatively under the action of the reset compression spring (57), and the two electrode blocks (56) are mutually contacted and pressed;

and the two electrode blocks (56) are respectively and electrically connected with a lead (61), and an alarm and a power supply (62) are connected on the lead (61) in series.

2. The condensing waste heat pressure-bearing hot water boiler according to claim 1, characterized in that: the electrode block (56) sets firmly metal shrapnel (59) respectively on the side of slider (52) dorsad, two metal shrapnel (59) set up along insulator spindle (53) central line direction interval, insulator spindle (53) all have the projection on two metal shrapnel (59) along self axis direction, insulator spindle (53) can promote two metal shrapnel (59) dorsad metal shrapnel (59) and the one end that resets board (58) and be connected contradict each other and compress tightly along self axis direction and when moving towards metal shrapnel (59) direction.

3. The condensing waste heat pressure-bearing hot water boiler according to claim 2, characterized in that: the outer pipe (51) is provided with a pressure relief hole (511), and the pressure relief hole (511) is located at one end, close to the fixing ring (54), of the side face of the outer pipe (51).

4. The condensing waste heat pressure-bearing hot water boiler according to claim 1, characterized in that: the sealing groove has been seted up to sliding block (52) side, the cover is equipped with sealing washer (521) of embedding in the sealing groove on sliding block (52), sealing washer (521) compress tightly with outer tube (51) lateral surface.

5. The condensing waste heat pressure-bearing hot water boiler according to claim 1, characterized in that: the alarm includes a buzzer (63) and a strobe (64).

6. The condensing waste heat pressure-bearing hot water boiler according to claim 1, characterized in that: the insulation rod (53) is fixedly provided with a limiting ring (532), and the limiting ring (532) is positioned on one side of the fixing ring (54) back to the sliding block (52).

7. The condensing waste heat pressure-bearing hot water boiler according to claim 1, characterized in that: the notch (561) is an arc-shaped opening.

8. The condensing waste heat pressure-bearing hot water boiler according to claim 1, characterized in that: one end of the insulating rod (53), which faces away from the sliding block (52), is fixedly provided with a circular truncated cone (531), and the large end of the circular truncated cone (531) is superposed with the end face of the insulating rod (53).