CN112814871A

CN112814871A - Inflating pump

Info

Publication number: CN112814871A
Application number: CN202110270625.XA
Authority: CN
Inventors: 胡勤毅
Original assignee: Hubei Hurun Electronics Co ltd
Current assignee: Hubei Hurun Electronics Co ltd
Priority date: 2021-03-12
Filing date: 2021-03-12
Publication date: 2021-05-18

Abstract

The invention relates to an inflating pump which is provided with a shell, an inflating assembly and a rechargeable battery module, wherein an assembling space is arranged inside the shell, and a concave accommodating groove is arranged outside the shell; the inflating assembly is assembled in the assembling space of the shell, a first plug connector is led out of the inflating assembly, and the first plug connector is arranged in the accommodating groove; the rechargeable battery module is movably embedded in the accommodating groove of the shell and is connected with the first plug connector in a matching way through a preset second plug connector, so that the rechargeable battery module is electrically connected with the inflating assembly; the charging battery module is provided with a charging input interface and a charging output interface; the inflating assembly is switched by a switch to use an external power supply to supply power for inflating or a rechargeable battery module to supply power for inflating. The inflating pump disclosed by the invention has the inflating function, and simultaneously integrates the rechargeable battery module, so that the inflating pump can be powered and inflated by an external power supply and the rechargeable battery module, the use performance is increased, the structure is simple, the size is small, the carrying is convenient, the functions are various, and the requirements of people in many ways are met.

Description

Inflating pump

Technical Field

The invention relates to the technical field of air compression equipment, in particular to a portable inflating pump.

Background

The inflating pump, especially the inflating pump with motor to drive the piston to reciprocate inside the compressing cylinder to produce pressurized gas, includes mainly pedestal, motor, compressing cylinder and piston.

With the gradual increase of the automobile possession, many owners can equip the automobile with an inflation pump for the reasons of convenience of tire inflation and the like. However, the existing inflating pump mainly uses electricity by connecting with a cigarette lighter of an automobile, so that the use is inconvenient and the application is limited; the utility model is affected by the structure, the body shape is relatively large, the working stability is not good, the function is single, and the requirements of people in many ways cannot be met.

Disclosure of Invention

The invention aims to provide an inflating pump, which solves the technical problems, realizes the power supply and inflation of an external power supply and the power supply and inflation of a self-contained rechargeable battery, is more convenient to use and improves the service performance; the self-contained rechargeable battery can help the automobile to start in an emergency when the automobile is flamed out and cannot be started when being anchored, and can also charge digital equipment such as a mobile phone and a tablet personal computer at any time and any place, so that the multifunctional automobile charger is multifunctional and meets the requirements of people in many ways.

In order to achieve the purpose, the invention adopts the following technical scheme:

an inflation pump, comprising:

the inner part of the shell is provided with an assembling space, and the outer part of the shell is provided with a concave accommodating groove;

the inflating assembly is assembled in the assembling space of the shell, and the electric control part of the inflating assembly leads out a first plug-in connector which is arranged in the accommodating groove;

the rechargeable battery module is movably embedded in the accommodating groove of the shell and is connected with the first plug connector in a matching way through a preset second plug connector, so that the rechargeable battery module is electrically connected with the inflating assembly; the rechargeable battery module is at least provided with a charging input interface and a charging output interface;

the inflating assembly is switched by a switch to use an external power supply to supply power for inflating or a rechargeable battery module to supply power for inflating.

The scheme is further that an embedding guide rail is arranged in the accommodating groove of the outer shell, and the extending direction of the embedding guide rail is consistent with the direction of the first plug connector in the connection with the second plug connector; the rechargeable battery module is provided with an embedding guide groove, and the direction of an introduction port of the embedding guide groove is consistent with that of an opening of the second plug connector; the second plug connector is inserted into the accommodating groove of the shell in an aligned mode and guides the first plug connector to be aligned and inserted through the combined connection of the embedding guide rail and the embedding guide groove.

The rechargeable battery module comprises a bottom plate, an upper cover, a circuit board and a battery, wherein the bottom plate and the upper cover are combined to form a box shape, and the circuit board and the battery are embedded between the bottom plate and the upper cover; the battery is connected with the circuit board in a conduction way, and the circuit board is provided with a charging and discharging circuit and is also electrically connected with the second plug connector, the charging input interface and the charging output interface; the embedding guide groove is constructed on the bottom plate, an arched part is further arranged on the bottom plate, the arched part and the embedding guide groove are arranged in parallel and surround the second plug-in connector, and an inserting gap is reserved between the periphery of the second plug-in connector and the inner wall of the arched part; the inserting gap is used for inserting a preset positioning column on the shell to align, and the positioning column is hollow and embedded with a first inserting connector.

The above-mentioned scheme is further, the section of scarf joint guide rail and scarf joint guide slot is the T font, and the scarf joint guide rail is flat lies on the interior bottom surface of holding tank, and shape, size and the rechargeable battery module of holding tank are unanimous.

The technical scheme is that the assembly space of the shell is in an L shape distributed around the periphery of the accommodating groove, the inflating assembly is distributed along the L shape and comprises a base, a motor and a piston, the base is fixedly connected with the shell and transversely arranged at the output end of the motor, a compression cylinder is arranged at one end, far away from the motor, of the base, the piston is axially arranged in the compression cylinder, one end, exposed out of the compression cylinder, of the piston is hinged to a gear set, the gear set transmits power output by the motor to the piston, the piston reciprocates in the compression cylinder to complete gas suction, compression and pressurized gas discharge, and a gas pipe connector is arranged at the exhaust end of the compression cylinder and exposed out of the shell.

In the above scheme, the gear set includes a first gear, a second gear, a third gear and a fourth gear, the first gear is connected to the output shaft of the motor and is engaged with the second gear, the third gear and the second gear are coaxially assembled and are engaged with the fourth gear, the fourth gear is hinged to the piston, and the hinged position is offset from the rotation center of the fourth gear; the gear set, the piston and the compression cylinder are arranged on one side of the base, and the motor is positioned on the other side of the base; the motor and the base are arranged in an L shape.

According to the scheme, the output shaft of the motor is further provided with radiating fan blades, the radiating fan blades and the gear set are located on the same side of the base, the corresponding parts of the base are provided with air flow holes, the shell is provided with a first air window and a second air window, the first air window and the second air window are respectively opposite to the front end and the rear end of the motor, and the radiating fan blades, the air flow holes, the first air window and the second air window form a radiating system.

The above scheme is further that a first-stage speed reduction transmission is adopted between the first gear and the second gear, a second-stage speed reduction transmission is adopted between the third gear and the fourth gear, and the speed reduction ratio of the second-stage speed reduction transmission is larger than that of the first-stage speed reduction transmission.

In the above scheme, the fourth gear is provided with a counterweight part, and the hinge position of the counterweight part and the piston hinged to the fourth gear is arranged in a manner of being opposite to the rotation center of the fourth gear.

According to the invention, through the structural design of the shell, the inflating pump is integrated with the rechargeable battery module, the inflating pump is supplied with power by an external power supply and is inflated, the rechargeable battery module is supplied with power and is inflated, the use performance is increased, the structure is simple, the design is novel, the size is small, the carrying is convenient, the rechargeable battery module is movably disassembled and assembled, the automobile can be emergently helped to start when the automobile is flameout and anchored and cannot be started, digital equipment such as a mobile phone and a tablet personal computer can be charged at any time and any place, the functions are various, and the requirements of people in various directions are met.

Description of the drawings:

FIG. 1 is a schematic structural diagram of an embodiment of the present invention;

FIG. 2 is a schematic top view of the embodiment of FIG. 1;

FIG. 3 is a schematic diagram of the structural distribution in the assembly space of the embodiment of FIG. 1;

FIG. 4 is a schematic diagram illustrating the positional relationship between the pump assembly and the rechargeable battery module of the embodiment of FIG. 1;

FIG. 5 is a schematic diagram of the rechargeable battery module of the embodiment of FIG. 1;

FIG. 6 is a schematic diagram of the external structure of the rechargeable battery module of the embodiment of FIG. 1;

FIG. 7 is an exploded view of the rechargeable battery module of the embodiment of FIG. 1;

fig. 8 is a schematic diagram of the rechargeable battery module of the embodiment of fig. 1 used as an emergency starting power supply.

The specific implementation mode is as follows:

the conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings to fully understand the objects, the features and the effects of the present invention.

It should be noted that in the description of the present invention, the terms of direction or positional relationship indicated by the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, which are merely for convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Referring to fig. 1 to 7, which are drawings illustrating a preferred embodiment of the present invention, the present invention relates to an inflation pump which is convenient for portable use and can be used for inflating tires of automobiles and motorcycles. The rechargeable battery module comprises a shell 1, an inflating assembly 2 and a rechargeable battery module 3, wherein an assembling space 11 is arranged inside the shell 1, and a concave accommodating groove 12 is arranged outside the shell 1; the inflating assembly 2 is assembled in the assembling space 11 of the shell 1, and the electric control part of the inflating assembly 2 leads out a first plug-in connector 21, and the first plug-in connector 21 is arranged in the accommodating groove 12; the rechargeable battery module 3 is movably embedded in the accommodating groove 12 of the shell 1 and is matched and connected with the first plug connector 21 through a preset second plug connector 31, so that the rechargeable battery module 3 is electrically connected with the inflating assembly 2; the rechargeable battery module 3 is at least provided with a charging input interface 32 and a charging output interface 33; the inflating assembly 2 uses an external power supply to supply power for inflating or the rechargeable battery module 3 supplies power for inflating through switch switching. Therefore, the inflating assembly 2 can be powered and inflated by an external power supply, such as a cigarette lighter connected with an automobile to get electricity, and can also be powered and inflated by the rechargeable battery module 3, so that the usability is improved, and the inflating assembly is suitable for outdoor use and can also be used for inflating motorcycles and the like. The rechargeable battery module 3 is at least provided with a charging input interface 32 and a charging output interface 33, so that the rechargeable battery module can be detached for charging and can be used for charging digital equipment such as mobile phones and tablet computers at any time and any place, and the rechargeable battery module has various functions and meets various requirements of people. In addition, as shown in fig. 8, the rechargeable battery module 3 can also help the vehicle to start in an emergency when the vehicle is turned off and cannot be started, and the power output by the second plug connector 31 is used to start the vehicle in a matching manner, so that the effect of starting the power supply in an emergency is achieved. At this moment, the clamp 101 is arranged at one end of the external live wire 100, the third plug connector 102 which is connected with the second plug connector 31 in an adaptive mode is arranged at the other end of the external live wire, the third plug connector 102 is plugged into the second plug connector 31, the clamp 101 is connected with a battery electrode on the automobile, and therefore the rechargeable battery module 3 provides an emergency starting power supply to help the automobile to start, the structure is simple, the use is convenient, and emergency requirements are met.

Referring to fig. 1 to 7, in the present embodiment, an embedding guide rail 13 is disposed in the accommodating groove 12 of the housing 1, and an extending direction of the embedding guide rail 13 is the same as a direction in which the first plug connector 21 is plugged into the second plug connector 31; the rechargeable battery module 3 is provided with an embedding guide groove 342, and an introduction port of the embedding guide groove 342 and an opening of the second plug connector 31 face the same direction; the engagement of the rechargeable battery module 3 in the receiving groove 12 of the housing 1 and the aligned engagement of the first plug connector 21 with the second plug connector 31 are guided by the combined engagement of the engagement rail 13 and the engagement groove 342. Convenient, effectual counterpoint equipment, rechargeable battery module 3 inlays when establishing holding tank 12, has also accomplished the electric conduction connection of first bayonet joint 21 counterpoint grafting second bayonet joint 31. In this embodiment, the rechargeable battery module 3 includes a bottom plate 34, an upper cover 35, a circuit board 36 and a battery 37, and the bottom plate 34 and the upper cover 35 are combined to form a box shape, so that the rechargeable battery module has good integrity and is convenient to carry and use. The circuit board 36 and the battery 37 are embedded between the bottom plate 34 and the upper cover 35, the battery 37 has replaceability, and the practicability is improved, in the embodiment of the figure, the upper cover 35 forms a cover shape to cover the bottom plate 34, and the buckle combination is adopted, so that the disassembly and the assembly can be carried out. The battery 37 is in conductive connection with the circuit board 36, and the circuit board 36 is provided with a charging and discharging circuit and is also electrically connected with the second plug connector 31, the charging input interface 32 and the charging output interface 33; the battery 37 is charged through the charging input interface 32, and digital equipment such as a mobile phone, a tablet personal computer and the like can be charged anytime and anywhere through the charging output interface 33; and power can be supplied to the inflating assembly 2 through the second plug connector 31 for inflating. The embedding guide groove 342 is formed on the bottom plate 34, and an arched portion 341 is further provided on the bottom plate 34, the arched portion 341 and the embedding guide groove 342 are arranged in parallel and surround the second plug 31, and an inserting gap 38 is left between the outer periphery of the second plug 31 and the inner wall of the arched portion 341; the inserting gap 38 is used for inserting and aligning a positioning column 14 preset on the housing 1, and the positioning column 14 is hollow and is embedded with the first inserting-connecting head 21. This structure realizes multistage grafting cooperation, connects more stably, has the shockproof effect of preferred, guarantees that first bayonet joint 21 and second bayonet joint 31 are direct stable, effectual electric connection. In this embodiment, the first plug 21 includes two parallel pins 211 and a reinforcing guide post 212 located between the two pins, and correspondingly, the second plug 31 includes an insulator 311 and conductive pinholes 312 disposed on the insulator 311, the number and the positions of the conductive pinholes 312 correspond to the pins 211 of the first plug 21, the insulator 311 is also correspondingly provided with a reinforcing guide hole 313, and the reinforcing guide hole 313 is matched with the reinforcing guide post 212 for plugging, but in practical applications, the effect of grounding achieved by the reinforcing guide hole 313 and the reinforcing guide post 212 is not excluded. When the structure is assembled, the insulator 311 is inserted into the inner hollow area of the positioning column 14, so that the insertion effect is further increased, the insertion pin 211 is electrically conducted with the conductive pin hole 312, and the reinforcing guide hole 313 is matched with the reinforcing guide column 212 for insertion, so that the insertion effect is further increased; thereby improving the assembly and use efficiency of the rechargeable battery module 3. The section of scarf joint guide rail 13 and scarf joint guide slot 342 is the T font, and scarf joint guide rail 13 lies on the interior bottom surface of holding tank 12, and the shape, the size of holding tank 12 are unanimous with rechargeable battery module 3, and this structure reaches the convenient dismouting of rechargeable battery module 3, and has corresponding anticreep nature. In the embodiment shown in the figures, the accommodating groove 12 is a semi-closed frame shape, and the accommodating groove 12 correspondingly holds the rechargeable battery module 3 while providing a limit to the corresponding peripheral wall, so that the rechargeable battery module 3 is completely fused to the housing 1 to form a stable whole. When the rechargeable battery module 3 needs to be taken out, the rechargeable battery module 3 is pushed out in a forced reverse direction.

Referring to fig. 1 to 5, in the present embodiment, the assembly space 11 of the housing 1 is L-shaped and distributed around the periphery of the receiving groove 12, the inflating assembly 2 is distributed along the L-shape, the inflating assembly 2 includes a base 22, a motor 23 and a piston 24, the base 22 is fixedly connected to the housing 1 and transversely disposed at an output end of the motor 23, one end of the base 22 away from the motor 23 is provided with a compression cylinder 25, the piston 24 is axially installed in the compression cylinder 25, and one end of the piston 24 exposed out of the compression cylinder 25 is hinged to a gear set, the gear set transmits power output by the motor 23 to the piston 24, so that the piston 24 reciprocates in the compression cylinder 25 to complete suction, compression and discharge of pressurized gas, an exhaust end of the compression cylinder 25 is provided with a gas pipe joint 251, and the gas pipe joint 251 is exposed out of the housing 1 so as to connect with an external gas pipe for inflating. In this embodiment, the air pipe connector 251 has an internal connection thread, so as to connect the air pipe conveniently and quickly. In this embodiment, the gear set includes a first gear 261, a second gear 262, a third gear 263 and a fourth gear 264, the first gear 261 is connected to the output shaft of the motor 23 and is engaged with the second gear 262, and the third gear 263 is coaxially assembled with the second gear 262 and is engaged with the fourth gear 264; the second gear 262, the third gear 263 and the fourth gear 264 are rotatably mounted on the base 22, and the gear set, the piston 24 and the compression cylinder 25 are arranged on the same side of the base 22, so that the structure is compact, and the work is stable and reliable; the fourth gear 264 is hinged to the piston 24 and the hinged position is offset from the rotation center of the fourth gear 264, so that the rotation is converted into the reciprocating motion of the piston 24. The motor 23 is positioned on the other side of the base, and the motor 23 and the base 22 are arranged in an L shape and matched with the shape of the assembly space 11, so that the structural design of the shell is facilitated to be optimized, and the inflating pump disclosed by the invention is small in volume and convenient to carry.

Referring to fig. 1 to 5, in the embodiment, a first-stage deceleration transmission is performed between the first gear 261 and the second gear 262, a second-stage deceleration transmission is performed between the third gear 263 and the fourth gear 264, and the reduction ratio of the second-stage deceleration transmission is greater than that of the first-stage deceleration transmission, so that the transmission is stable, a better rotating torque is obtained, the gas suction, the compression and the pressurized gas discharge are facilitated, the air compression amount is increased, and the inflation efficiency is improved. In this embodiment, a counterweight 2641 is disposed on the fourth gear 264, and the hinge position of the piston 24 where the counterweight 2641 is hinged to the fourth gear 264 is arranged in a manner to be opposite to the rotation center of the fourth gear 264, so that the structure improves the mobility of the fourth gear 264, obtains a smooth and powerful rotating torque, and improves the usability of the inflation pump.

Referring to fig. 1 to 5, in the embodiment, the output shaft of the motor 23 is further assembled with a heat dissipating fan 27, and the heat dissipating fan 27 and the gear set are located on the same side of the base 22, so that the structure is compact and the assembly and maintenance are convenient. The base 22 is provided with an airflow hole 221 at a corresponding position, the housing is provided with a first air window 15 and a second air window 16 which are respectively opposite to the front end and the rear end of the motor 23, and the heat dissipation fan 27, the airflow hole 221, the first air window 15 and the second air window 16 form a heat dissipation system. In operation, the heat dissipation system can provide heat to the motor 23, the gear set and the piston 24 well, so as to achieve continuous operation without overheating and causing breakdown of the inflation pump.

According to the invention, through the structural design of the shell 1, the inflating assembly 2 and the rechargeable battery module 3 are combined conveniently, so that the inflating function is realized, and meanwhile, a mobile power supply is also provided. The inflating pump can be powered by an external power supply to inflate, and also can be powered by a rechargeable battery module to inflate, so that the using performance is increased, the structure is simple, the design is novel, the size is small, and the carrying is convenient. The rechargeable battery module realizes movable disassembly and assembly, can help the automobile to start in an emergency when the automobile is flamed out and cannot be started when being anchored, can also charge digital equipment such as a mobile phone and a tablet personal computer at any time and any place, has various functions, and meets the requirements of people in many directions.

It is to be understood that the foregoing detailed description of the present invention has been provided only for the purpose of illustrating the technical spirit and features of the present invention, and the present invention is not limited thereto.

Claims

1. An inflation pump, comprising:

the device comprises a shell (1), wherein an assembling space (11) is arranged inside the shell (1), and a concave accommodating groove (12) is arranged outside the shell (1);

the inflating assembly (2), the inflating assembly (2) is assembled in the assembling space (11) of the shell (1), the electric control part of the inflating assembly (2) leads out a first plug-in connector (21), and the first plug-in connector (21) is arranged in the accommodating groove (12);

the rechargeable battery module (3), the rechargeable battery module (3) is movably embedded in the accommodating groove (12) of the shell (1) and is connected with the first plug connector (21) through the preset second plug connector (31) in a matching way, so that the rechargeable battery module (3) is electrically connected with the inflating assembly (2); the rechargeable battery module (3) is also at least provided with a charging input interface (32) and a charging output interface (33);

the inflating assembly (2) uses an external power supply to supply power for inflating or the rechargeable battery module (3) supplies power for inflating through switch switching.

2. An inflation pump according to claim 1, characterized in that an engagement guide (13) is provided in the receiving groove (12) of the housing (1), the engagement guide (13) extending in the same direction as the first plug (21) in which the second plug (31) is inserted; the rechargeable battery module (3) is provided with an embedding guide groove (342), and the direction of an introduction port of the embedding guide groove (342) is consistent with that of an opening of the second plug connector (31); the combined connection of the embedding guide rail (13) and the embedding guide groove (342) guides the rechargeable battery module (3) to be embedded into the accommodating groove (12) of the housing (1) and guides the first plug connector (21) to be in contraposition with the second plug connector (31).

3. An air pump according to claim 1 or 2, wherein the rechargeable battery module (3) comprises a bottom plate (34), an upper cover (35), a circuit board (36) and a battery (37), the bottom plate (34) and the upper cover (35) are combined to form a box shape, and the circuit board (36) and the battery (37) are embedded between the bottom plate (34) and the upper cover (35); the battery (37) is in conductive connection with the circuit board (36), and the circuit board (36) is provided with a charging and discharging circuit and is also electrically connected with the second plug connector (31), the charging input interface (32) and the charging output interface (33); the embedding guide groove (342) is formed in the bottom plate (34), an arc-shaped part (341) is further arranged on the bottom plate (34), the arc-shaped part (341) and the embedding guide groove (342) are arranged in parallel and surround the second plug-in connector (31), and an inserting gap (38) is reserved between the periphery of the second plug-in connector (31) and the inner wall of the arc-shaped part (341); the inserting gap (38) is used for inserting and aligning a positioning column (14) preset on the shell (1), and the positioning column (14) is hollow and embedded with the first inserting-connecting head (21).

4. The inflation pump according to claim 2, wherein the engagement guide rail (13) and the engagement guide groove (342) have a T-shaped cross section, the engagement guide rail (13) lies flat on an inner bottom surface of the receiving groove (12), and the receiving groove (12) has a shape and a size corresponding to those of the rechargeable battery module (3).

5. An air pump according to claim 1, wherein the assembly space (11) of the housing (1) is L-shaped and distributed around the periphery of the receiving groove (12), the air pump assembly (2) is distributed along the L-shape, the air pump assembly (2) comprises a base (22), a motor (23) and a piston (24), the base (22) is fixedly connected with the housing (1) and transversely arranged at the output end of the motor (23), a compression cylinder (25) is arranged at one end of the base (22) far away from the motor (23), the piston (24) is axially arranged in the compression cylinder (25), one end of the piston (24) exposed out of the compression cylinder (25) is hinged with a gear set, the gear set transmits the power output by the motor (23) to the piston (24), so that the piston (24) reciprocates in the compression cylinder (25) to complete the suction, compression and discharge of the pressurized air, the exhaust end of the compression cylinder (25) is provided with an air pipe joint (251), and the air pipe joint (251) is exposed on the shell (1).

6. The air pump as claimed in claim 5, wherein the gear set comprises a first gear (261), a second gear (262), a third gear (263) and a fourth gear (264), the first gear (261) is connected with the output shaft of the motor (23) and is meshed with the second gear (262), the third gear (263) is coaxially assembled with the second gear (262) and is meshed with the fourth gear (264), and the fourth gear (264) is hinged with the piston (24) and is offset from the rotation center of the fourth gear (264); the gear set, the piston (24) and the compression cylinder (25) are arranged on one side of the base (22), and the motor (23) is arranged on the other side of the base; the motor (23) and the base (22) are arranged in an L shape.

7. The inflation pump according to claim 6, wherein the output shaft of the motor (23) is further assembled with a heat dissipating fan (27), the heat dissipating fan (27) and the gear set are located on the same side of the base (22), the base (22) is provided with an air flow hole (221) at a corresponding portion, and the housing is provided with a first air window (15) and a second air window (16) respectively facing the front end and the rear end of the motor (23), and the heat dissipating fan (27), the air flow hole (221), the first air window (15) and the second air window (16) constitute a heat dissipating system.

8. An air pump according to claim 6, wherein the first gear (261) and the second gear (262) are in a first stage of speed reduction transmission, the third gear (263) and the fourth gear (264) are in a second stage of speed reduction transmission, and the speed reduction ratio of the second stage of speed reduction transmission is larger than that of the first stage of speed reduction transmission.

9. An inflation pump according to claim 6 or 8, wherein the fourth gear (264) is provided with a weight portion (2641), and the hinge position of the piston (24) in hinge connection with the fourth gear (264) of the weight portion (2641) is arranged in a manner to be opposite to the rotation center of the fourth gear (264).