CN213928664U

CN213928664U - Safety air pump

Info

Publication number: CN213928664U
Application number: CN202023223454.5U
Authority: CN
Inventors: 刘之明
Original assignee: Shandong Taizhan Mechanical And Electrical Technology Co ltd
Current assignee: Shandong Taizhan Mechanical And Electrical Technology Co ltd
Priority date: 2020-12-29
Filing date: 2020-12-29
Publication date: 2021-08-10
Anticipated expiration: 2030-12-29

Abstract

The utility model discloses a safety air pump belongs to varactor formula machinery technical field, and its second grade cylinder includes casing, characterized in that: a first-stage cylinder cavity, a connecting cavity and a second-stage cylinder cavity which are distributed in sequence are arranged in the shell, the connecting cavity is communicated with the external atmosphere, a motor is installed on the connecting cavity, an eccentric shaft is installed on a rotating shaft of the motor, the first-stage cylinder cavity and the second-stage cylinder cavity are distributed in a relative mode, and the radial section of the second-stage cylinder cavity is smaller than that of the first-stage cylinder cavity. The air pump enables the primary piston and the secondary piston to move towards the same direction at the same time, and the primary rodless cavity and the secondary rodless cavity alternately suck air and compress the air during normal work, so that the work efficiency is improved; when the motor is abnormal and does not work, standby gas can be simultaneously conveyed to the first-stage rodless cavity and the second-stage rodless cavity through the low-pressure air nozzle, pressure difference is generated by the two rodless cavities with different radial sections to pressurize the gas in the second-stage rodless cavity, high-pressure gas can still be supplied, a buffer time is given to a vehicle, and the driving safety of the vehicle is improved.

Description

Safety air pump

Technical Field

The utility model belongs to the technical field of varactor formula machinery, concretely relates to safety air pump.

Background

With the development of the automobile industry technology, the air suspension technology is gradually perfected and is gradually applied to the suspension system of the vehicle. The air spring is used for buffering vibration from wheels, the air pressure of the air spring is adjusted in real time according to road conditions, the hardness of the air spring is changed accordingly, and the purposes of improving comfort and stability of a vehicle in the driving process are achieved.

In practical applications, an air pump is usually used to provide compressed air for the air spring, so as to adjust the elastic coefficient of the air spring. When the air spring needs to be hardened, the air pump works, and air is compressed and then is filled into the air spring; when the air spring needs to be softened, part of the compressed air is released.

Most of the existing air pumps can stop supplying compressed air to a suspension system when a motor stops working due to abnormality, so that the comfort of a running vehicle is influenced, and even the running safety of the vehicle is endangered. Therefore, further improving the safety of the air suspension system of the vehicle is a technical problem that those skilled in the art need to overcome.

Disclosure of Invention

The utility model aims to solve the technical problem that a safety air pump is provided, can still supply out after the pressurization of reserve compressed gas under the unusual and inoperative condition of motor.

In order to solve the technical problem, the technical scheme of the utility model is that: the design safety air pump, including the second grade cylinder, the second grade cylinder includes casing, its characterized in that: the shell is internally provided with a primary cylinder cavity, a connecting cavity and a secondary cylinder cavity which are sequentially distributed, the connecting cavity is communicated with the outside atmosphere, a motor is arranged on the connecting cavity, an eccentric shaft is arranged on a rotating shaft of the motor, the primary cylinder cavity and the secondary cylinder cavity are oppositely distributed, and the radial section of the secondary cylinder cavity is smaller than that of the primary cylinder cavity;

a first-stage piston is assembled in the first-stage cylinder cavity, the first-stage piston divides the first-stage cylinder cavity into a first-stage rod cavity and a first-stage rodless cavity, a first-stage air inlet is formed in the first-stage piston and is communicated with the first-stage rod cavity and the first-stage rodless cavity, a first one-way valve capable of switching on and off the first-stage air inlet is arranged on the first-stage air inlet, a first-stage rodless cavity is communicated with a first-stage air outlet, and a second one-way valve capable of switching on and off the first-stage air outlet is arranged on the first-stage air outlet;

a second-stage piston is assembled in the second-stage cylinder cavity, the second-stage piston divides the second-stage cylinder cavity into a second-stage rod cavity and a second-stage rodless cavity, the second-stage rodless cavity is communicated with a second-stage air inlet hole and a second-stage air outlet hole, a third one-way valve capable of switching on and off the second-stage air inlet hole is arranged on the second-stage air inlet hole, and a fourth one-way valve capable of switching on and off the second-stage air outlet hole is arranged on the second-stage air outlet hole;

the first-stage piston is connected with a first-stage piston rod, the second-stage piston is connected with a second-stage piston rod, the first-stage piston rod is hinged with the second-stage piston rod in a connecting cavity, a connecting hole is formed in the first-stage piston rod or the second-stage piston rod, and the connecting hole is assembled with the eccentric shaft;

the gas path switching valve comprises a valve seat, the valve seat is connected with the shell, a low-pressure gas nozzle and a high-pressure gas nozzle are arranged on the valve seat, the valve seat and the shell jointly enclose a first gas cavity, a second gas cavity and a third gas cavity which are mutually independent, the first gas cavity is communicated with the first-stage gas outlet hole, the first gas cavity is also communicated with the second-stage gas inlet hole, the low-pressure gas nozzle is connected with the first gas cavity through a first switch valve, the second gas cavity is communicated with the second-stage gas outlet hole, and the third gas cavity is communicated with the high-pressure gas nozzle;

the valve seat is internally provided with a cavity, the cavity is internally provided with a valve core, the valve core divides the cavity into a first valve cavity and a second valve cavity which are distributed in sequence and are mutually independent, the first valve cavity is communicated with the second air cavity, the second valve cavity is communicated with the third air cavity, the valve core is provided with a fifth one-way valve, and the fifth one-way valve is positioned between the first valve cavity and the second valve cavity.

Furthermore, the valve core is provided with a small end and a large end with a radial section larger than the small end, the cavity is further provided with a third valve cavity located at the end of the cavity, the third valve cavity is arranged close to the second valve cavity, the large end is located in the third valve cavity, the large end is connected to the valve seat through an elastic body, a fourth gas cavity is further enclosed between the valve seat and the shell, the valve core further divides the cavity into the fourth valve cavity, the fourth valve cavity is located on one side of the first valve cavity and far away from the second valve cavity, the fourth valve cavity is communicated with the fourth gas cavity, the fourth gas cavity is communicated with a pressure regulating gas port, and the pressure regulating gas port is communicated with the secondary gas outlet hole.

The valve seat is provided with a first valve cavity, the valve seat is provided with a first valve hole, the valve seat is provided with a second valve hole, the first valve hole is provided with a first valve cavity, the second valve cavity is provided with a second valve cavity, the first valve cavity is provided with a first valve cavity, the second valve cavity is provided with a second valve cavity, the fifth valve cavity is provided with a fourth valve cavity, the fifth valve cavity is provided close to the fourth valve cavity, a fifth air cavity is provided between the valve seat and the shell, a fifth air cavity is provided with a fifth air cavity, and a fifth air cavity, a fifth air cavity is provided between the fifth air cavity and a fifth air cavity is surrounded between the fifth cavity and a fifth air cavity is communicated with a fifth cavity.

Furthermore, the third air cavity is communicated with the connecting cavity through a second switch valve.

Furthermore, a sixth air cavity is arranged between the valve seat and the shell in a surrounding mode, the third air cavity is communicated with the air inlet end of the second switch valve, the sixth air cavity is communicated with the air outlet end of the second switch valve, and the sixth air cavity is communicated with the connecting cavity.

Further, the motor comprises a shell, a front end cover and a rear end cover are arranged on the shell, an air faucet is arranged on the rear end cover and communicated with an inner cavity of the shell, and a first air vent penetrating through the front end cover is formed in the front end cover.

Furthermore, a first buffer cavity is defined between the air tap and the rear end cover, the air tap is communicated with the first buffer cavity, a second vent hole is formed in the rear end cover, one end of the second vent hole is communicated with the first buffer cavity, and the other end of the second vent hole is communicated with the inner cavity of the casing.

Further, install the drying cylinder on the casing, the drying cylinder includes the first jar of body and the second jar of body that establish ties each other, and the first jar of body encloses with the casing has the second cushion chamber, and the fourth check valve is arranged in the second cushion chamber, and the second jar of body encloses with the casing has the third cushion chamber, and the third cushion chamber is linked together through high-pressure gas port and second air cavity.

Furthermore, the valve further comprises a limiting piece, the fourth check valve is a fourth valve piece which can be opened in the direction away from the second-stage rodless cavity, and the limiting piece can block the opened fourth valve piece.

Furthermore, the first check valve is a first valve plate, the first valve plate is arranged on the end wall of the primary piston, and the first valve plate is arranged close to the primary rodless cavity; the second check valve is a second valve plate which can be opened towards the direction far away from the primary rodless cavity; the third check valve is a third valve plate which can be opened towards the direction of the second-stage rodless cavity.

Compared with the prior art, the beneficial effects of the utility model are that:

1. the utility model enables the primary piston and the secondary piston to move towards the same direction at the same time, and the primary rodless cavity and the secondary rodless cavity alternately suck and compress during normal work, thereby improving the work efficiency; when the motor is abnormal and does not work, standby gas can be simultaneously conveyed to the first-stage rodless cavity and the second-stage rodless cavity through the low-pressure air nozzle, pressure difference is generated by the two rodless cavities with different radial sections to pressurize the gas in the second-stage rodless cavity, high-pressure gas can still be supplied, a buffer time is given to a vehicle, and the driving safety of the vehicle is improved.

2. Because the valve core is arranged in the valve seat through the elastic body, and the fourth valve cavity collects the sample gas of the secondary gas outlet, the position of the valve core in the cavity can be properly adjusted through the combined action of the pressurized sample gas and the elastic body, and the change of the pressure of the gas output by the secondary gas outlet is met.

3. Because the fifth valve cavity at the other end of the cavity is communicated with the connecting cavity in a normal pressure state, the valve core can be in a free state, and the valve core is prevented from being influenced by vacuum or pressure in the moving process.

4. Because the third air cavity still connects the chamber through second ooff valve intercommunication, can be so that the gas that passes in and out among the suspension system all can be through connecting the chamber and circulate through the air cock, take away the heat that click operation produced, realize the self-cooling of motor, do benefit to and prolong its life.

5. Because the buffer cavity is arranged between the air tap and the rear end cover, the rear end cover is provided with the second vent hole for communicating the buffer cavity with the inner cavity of the shell, so that the gas with the fast flow rate entering from the air tap can be released and relaxed in the space of the buffer cavity, the impact on the inner part of the shell is relieved, and the service life of the motor can be further prolonged.

6. Because the first check valve, the second check valve, the third check valve and the fourth check valve all adopt the form of the elastic valve plate, the structure of the check valves is simplified, and the installation structure is also simplified, so that the cylinder is more compact in structure, fault points are reduced, and the stability of the operation of the cylinder is favorably maintained.

7. Because still set up the spacing piece that can restrict the fourth valve block and open the degree, can avoid the fourth valve block because of the too big circumstances that can not normally reset of damage of expansion range, further guarantee the reliable work of cylinder.

8. The utility model discloses can distribute the spare gas that the low pressure air cock supplyed simultaneously to the different rodless chamber in two radial cross sections, utilize pressure differential promotion piston to the less rodless chamber side movement in radial cross section, will spare gas pressurization to improve the security of vehicle, be convenient for in industry popularize and apply.

Drawings

FIG. 1 is a perspective view of the present invention;

FIG. 2 is a view in the direction A of FIG. 1;

FIG. 3 is a cross-sectional view C-C of FIG. 2 (not including the motor and dryer can);

FIG. 4 is a cross-sectional view taken along line D-D of FIG. 3;

FIG. 5 is a view from the direction B of FIG. 1;

FIG. 6 is a cross-sectional view E-E of FIG. 5;

FIG. 7 is an assembled structure view of the secondary cylinder and the air passage switching valve;

FIG. 8 is a perspective exploded view of the first secondary cylinder;

FIG. 9 is a second perspective exploded view of the secondary cylinder;

FIG. 10 is a view from direction F of FIG. 8;

FIG. 11 is a sectional view taken along line G-G of FIG. 10;

FIG. 12 is a sectional view taken along line H-H of FIG. 11;

FIG. 13 is a schematic view of the structure of the motor;

fig. 14 is a sectional view taken along line I-I in fig. 13.

The labels in the figure are: 1. a gas path switching valve; 11. a valve seat; 12. a low pressure air tap; 13. a high-pressure air tap; 14. a first air cavity; 15. a second air cavity; 16. a third air cavity; 17. a fourth air cavity; 18. a fifth air cavity; 19. a sixth air cavity; 110. a valve core; 111. a fifth valve cavity; 112. a fourth valve cavity; 113. a first valve chamber; 114. a pressure check valve; 115. a second valve cavity; 116. a third valve cavity; 117. a spring; 118. a first solenoid valve; 119. a second solenoid valve; 120. a pressure regulating gas port; 121. a high pressure gas port; 2. a secondary cylinder; 21. a housing; 22. a connecting cavity; 23. a first-stage rod cavity; 24. a primary rodless cavity; 25. connecting holes; 26. a secondary piston; 27. hinging a shaft; 28. a second-stage rod cavity; 29. a secondary rodless cavity; 210. a primary air inlet; 211. a first valve plate; 212. a primary air outlet; 213. a second valve plate; 214. a secondary air inlet; 215. a third valve plate; 216. a fourth valve plate; 217. a limiting sheet; 218. a secondary air outlet; 219. a secondary piston rod; 220. a primary piston rod; 221. a primary piston; 222. a secondary piston; 3. a motor; 31. a housing; 32. a front end cover; 33. an eccentric shaft; 34. a first vent hole; 35. a rear end cap; 36. an air tap; 37. a first buffer chamber; 38. a second vent hole; 39. a rotating shaft; 4. a drying tank; 41. a first tank; 42. a second tank; 43. a second buffer chamber; 44. and a third buffer chamber.

Detailed Description

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

The utility model defines the end of the rotating shaft 39 of the motor 3 connected with the secondary cylinder 2 as the front end; the other end of the undriven device is defined as the backend accordingly.

As shown in fig. 1 and 2, the present invention provides a second-stage cylinder 2 and a gas circuit switching valve 1, a valve seat 11 is provided in the gas circuit switching valve 1, and a low pressure nozzle 12 and a high pressure nozzle 13 are provided on the valve seat 11. As shown in fig. 3 and 7, a casing 21 is disposed in the secondary cylinder 2, the valve seat 11 and the casing 21 together enclose a first air chamber 14, a second air chamber 15, a third air chamber 16, a fourth air chamber 17, a fifth air chamber 18 and a sixth air chamber 19 which are independent from each other, as shown in fig. 4, the low pressure air tap 12 is connected to the first air chamber 14 through a first solenoid valve 118, the third air chamber 16 is communicated with the high pressure air tap 13, the third air chamber 16 is further communicated with an air inlet end of a second solenoid valve 119, the sixth air chamber 19 is communicated with an air outlet end of the second solenoid valve 119, and the fourth air chamber 17 is communicated with a pressure regulating air port 120. As shown in fig. 11, a first-stage cylinder cavity, a connecting cavity 22 and a second-stage cylinder cavity are formed in the housing 21 and distributed in sequence, and the connecting cavity 22 is communicated with the fifth air cavity 18. The motor 3 is mounted on the connecting cavity 22, as shown in fig. 13, a front end cover 32 and a rear end cover 35 are arranged on a housing 31 of the motor 3, an air nozzle 36 is arranged on the rear end cover 35, a first buffer cavity 37 is defined between the air nozzle 36 and the rear end cover 35, the air nozzle 36 is communicated with the first buffer cavity 37, as shown in fig. 14, a second vent hole 38 is formed in the rear end cover 35, one end of the second vent hole 38 is communicated with the first buffer cavity 37, the other end of the second vent hole is communicated with an inner cavity of the housing 31, and a first vent hole 34 penetrating through the front end cover 32 is formed in the front end cover 32. A rotor is arranged in the machine shell 31, a rotating shaft 39 is fixed in the rotor, an eccentric shaft 33 extending out of the front end cover 32 is arranged on the rotating shaft 39, and the eccentric shaft 33 and the rotating shaft 39 are arranged in an eccentric mode.

The first-stage cylinder cavity and the second-stage cylinder cavity are distributed oppositely, and the radial section of the second-stage cylinder cavity is smaller than that of the first-stage cylinder cavity. The first-stage cylinder cavity is provided with a first-stage piston 221, and the first-stage piston 221 is connected with a first-stage piston rod 220. The primary piston 221 divides the primary cylinder chamber into a primary rod chamber 23 and a primary rodless chamber 24. As shown in fig. 8 and 9, a primary air inlet hole 210 is formed in the primary piston 221, the primary air inlet hole 210 communicates with the primary rod chamber 23 and the primary rodless chamber 24, a first valve plate 211 is mounted on an end wall of the primary piston 221, and the first valve plate 211 can cover the primary air inlet hole 210 and is arranged close to the side of the primary rodless chamber 24. The housing 21 is provided with a second valve plate 213, the second valve plate 213 can cover the first-stage air outlet hole 212, the first-stage air outlet hole 212 is communicated with the first air cavity 14, and the second valve plate 213 can only be opened towards the direction far away from the first-stage rodless cavity 24. The secondary cylinder cavity is provided with a secondary piston 26, the secondary piston 26 is connected with a secondary piston rod 219, the secondary piston rod 219 is hinged with a primary piston rod 220 in the connecting cavity 22 through a hinge shaft 27, the secondary piston rod 219 is provided with a connecting hole 25, and the eccentric shaft 33 is arranged in the connecting hole 25. The secondary piston 26 divides the secondary cylinder chamber into a secondary rod chamber 28 and a secondary rodless chamber 29, the secondary rodless chamber 29 communicates with a secondary air inlet hole 214 and a secondary air outlet hole 218, and the secondary air inlet hole 214 communicates with the first air chamber 14, and as shown in fig. 12, a third valve plate 215 capable of sealing the secondary air inlet hole 214 is provided on the housing 21 in the secondary rodless chamber 29, so that the third valve plate 215 can only open into the secondary rodless chamber 29. The shell 21 is further provided with a fourth valve plate 216 capable of sealing the secondary air outlet 218, the fourth valve plate 216 can only be opened towards the direction far away from the secondary rodless cavity 29, the shell 21 is further provided with a limiting plate 217, and the limiting plate 217 can block the opened fourth valve plate 216 to limit the opening degree of the fourth valve plate 216. The shell 21 is further provided with a drying tank 4 covered on the secondary air outlet 218, as shown in fig. 5 and 6, the drying tank 4 is provided with a first tank 41 and a second tank 42 which are connected in series, the first tank 41 and the shell 21 enclose a second buffer cavity 43, as shown in fig. 10, the second buffer cavity 43 is communicated with the pressure regulating air opening 120, the fourth valve plate 216 is located in the second buffer cavity 43, the second tank 42 and the shell 21 enclose a third buffer cavity 44, and the third buffer cavity 44 is communicated with the second air cavity 15 through the high-pressure air opening 121.

As shown in fig. 3, a cavity is formed in the valve seat 11, a valve core 110 is assembled in the cavity, the valve core 110 has a small end and a large end with a radial cross section larger than that of the small end, the valve core 110 divides the cavity into a fifth valve cavity 111, a fourth valve cavity 112, a first valve cavity 113, a second valve cavity 115 and a third valve cavity 116 which are independent from each other and are sequentially distributed along the valve core 110 from the small end to the large end, so that the third valve cavity 116 is located on one side of the cavity closest to the end wall of the large end, and the fifth valve cavity 111 is located on the other side of the cavity closest to the end wall of the small end. The big end of the spool 110 is located in the third valve chamber 116, and the big end is connected to the valve seat 11 by a spring 117. The first valve cavity 113 is communicated with the second air cavity 15, the third air cavity 16 is communicated with the second valve cavity 115, the valve core 110 is provided with a pressure one-way valve 114, the pressure one-way valve 114 is positioned between the first valve cavity 113 and the second valve cavity 115, and the pressure one-way valve 114 only allows air to flow from the first valve cavity 113 to the second valve cavity 115. The fourth valve chamber 112 communicates with the fourth air chamber 17, and the fifth valve chamber 111 communicates with the fifth air chamber 18.

The working process of the utility model is as follows:

when in use, the low-pressure air nozzle 12 is connected with an air storage tank for storing compressed air. Since the connection chamber 22 is communicated with the outside atmosphere through the air tap 36, the connection chamber 22 is always in a normal pressure state. Normally, the first solenoid valve 118 is in a closed state, and the motor 3 drives the first piston 221 and the second piston 26 to reciprocate simultaneously through the eccentric shaft 33. When the secondary piston rod 219 pushes towards the secondary cylinder cavity, the primary piston rod 220 is pulled out of the primary cylinder cavity, so that the primary rodless cavity 24 becomes large, the second valve plate 213 seals the primary air outlet hole 212, the first valve plate 211 seals the primary air inlet hole 210, the pressure in the primary rodless cavity 24 drops sharply, vacuum occurs, the first valve plate 211 is forced to open, the blocking effect on the primary air inlet hole 210 is lost, and air enters the primary air inlet hole 210 through the air nozzle 36 and the connecting cavity 22 and enters the primary rodless cavity 24. When the primary piston 221 pushes into the primary cylinder cavity, the primary rodless cavity 24 becomes smaller, the air in the primary rodless cavity is compressed, when the pressure is increased to a certain degree, the second valve plate 213 is pushed open, so that the compressed air enters the secondary air inlet 214 from the primary air outlet 212 and passes through the first air cavity 14, at this time, the third valve plate 215 is opened when the secondary rodless cavity 29 is in the process of being enlarged, the air compressed by the primary rodless cavity 24 enters the secondary rodless cavity 29, when the secondary piston rod 219 pushes into the secondary cylinder cavity again, the air pushes open the fourth valve plate 216 after passing through the secondary compression, is discharged from the secondary air outlet 218, enters the second buffer cavity 43, a part of the air enters the fourth valve cavity 112 through the pressure regulating air port 120 as sample air, and the rest of the air enters the second air cavity 15 through the high-pressure air port 121 after passing through the first tank 41 and the second tank 42, then reaches the first valve cavity 113, the pressure one-way valve 114 is opened under the action of pressure to enter the second valve cavity 115, and the air is supplied from the high-pressure air nozzle 13 through the third air chamber 16 so as to be filled into the air spring, enhance the hardness of the air spring and lift the vehicle frame at the corresponding part. Certainly, when the air spring needs to be softened, part of air can be pressed out, the pressed air enters the third air cavity 16 through the high-pressure air nozzle 13, at this time, the second electromagnetic valve 119 is opened, the part of air can pass through the second electromagnetic valve 119 to enter the connecting cavity 22, and finally, the part of air is discharged from the air nozzle 36 through the inner cavity of the motor 3, so that the softness and hardness of the air spring can be adjusted. Thus, when the primary piston rod 220 and the secondary piston rod 219 move together in the direction of the secondary rodless cavity 29, the primary rodless cavity 24 sucks air and the secondary rodless cavity 29 compresses; when the first-stage piston rod 220 and the second-stage piston rod 219 move towards the first-stage rodless cavity 24 together, the first-stage rodless cavity 24 compresses, and the second-stage rodless cavity 29 sucks air, namely the first-stage rodless cavity 24 and the second-stage rodless cavity 29 alternately suck air and compress air, so that no matter how the piston rods move, one rodless cavity is always in a state of really doing work, the working efficiency of the cylinder is improved, and the second-stage rodless cavity 29 compresses the air compressed by the first-stage rodless cavity 24 again, and the air supply pressure is improved. And the air entering and exiting the air pump flows through the inner cavity of the motor 3 to take away the heat generated by the operation of the motor 3, thereby realizing self-air cooling.

If the motor 3 is abnormal and stops working, the secondary air cylinder cannot be driven to work to generate compressed air. At this time, the first solenoid valve 118 is opened, so that the standby gas in the gas storage tank enters the first gas cavity 14 through the low-pressure air nozzle 12, enters the first rodless cavity through the first-stage gas outlet hole 212, and enters the second-stage rodless cavity 29 through the second-stage gas inlet hole 214, because the gas pressures of the first-stage rodless cavity 24 and the second-stage rodless cavity 29 are the same, but the radial section of the second-stage rodless cavity 29 is smaller than that of the first-stage rodless cavity 24, so that pressure difference is generated to push the piston to move to the side of the second-stage rodless cavity 29, the gas is pressurized, the high-pressure air nozzle 13 still supplies high-pressure air, the adjustment requirement of the air spring within a certain time is met, the defect that the air spring cannot be inflated due to the abnormity of the motor 3 in the prior art is avoided, and the driving safety of the vehicle is improved.

During the inflation process, the valve core 110 can properly adjust the position of the valve core 110 according to the change of the air supply pressure so as to meet the change of the air supply pressure.

Except for adopting the first electromagnetic valve 118 as a first switch valve and the second electromagnetic valve 119 as a second switch valve, the switch valve with other specific structures can be adopted as long as on-off control can be met, and only the electromagnetic valve is mature in technology, stable in performance and convenient to control on-off. Similarly, in addition to the spring 117 as an elastic body, an elastic body such as rubber may be used, and the elastic body may be flexible with the change of pressure, and the structure is not specifically required. Of course, the fifth check valve is in the form of a pressure check valve 114, and other check valves with different structures are also adopted only in consideration of the opening and closing control of the fifth check valve by pressure. First check valve, second check valve, third check valve and fourth check valve except adopting above-mentioned valve block structure, can also adopt the check valve of other concrete structures, as long as can control gaseous one-way circulation can, only adopt the valve block can self carry out automatic start-stop according to the pressure condition, not only simplified self structure, also simplified control structure for the overall structure of cylinder is compacter, has reduced the fault point, does benefit to the stability of cylinder operation.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical substance of the present invention still belong to the protection scope of the technical solution of the present invention.

Claims

1. A safety air pump, includes the second grade cylinder, and the second grade cylinder includes casing, its characterized in that: the shell is internally provided with a primary cylinder cavity, a connecting cavity and a secondary cylinder cavity which are sequentially distributed, the connecting cavity is communicated with the outside atmosphere, a motor is arranged on the connecting cavity, an eccentric shaft is arranged on a rotating shaft of the motor, the primary cylinder cavity and the secondary cylinder cavity are oppositely distributed, and the radial section of the secondary cylinder cavity is smaller than that of the primary cylinder cavity;

the gas path switching valve comprises a valve seat, the valve seat is connected with the shell, a low-pressure gas nozzle and a high-pressure gas nozzle are arranged on the valve seat, a first gas cavity, a second gas cavity and a third gas cavity which are mutually independent are enclosed by the valve seat and the shell, the first gas cavity is communicated with the first-stage gas outlet hole, the first gas cavity is also communicated with the second-stage gas inlet hole, the low-pressure gas nozzle is connected with the first gas cavity through a first switch valve, the second gas cavity is communicated with the second-stage gas outlet hole, and the third gas cavity is communicated with the high-pressure gas nozzle;

2. A safety air pump according to claim 1 wherein: the valve core is provided with a small end and a large end with a radial section larger than the small end, the cavity is further provided with a third valve cavity located at the end of the cavity, the third valve cavity is arranged close to the second valve cavity, the large end is located in the third valve cavity, the large end is connected to the valve seat through an elastic body, a fourth valve cavity is further enclosed between the valve seat and the shell, the valve core further divides the cavity into the fourth valve cavity, the fourth valve cavity is located on one side of the first valve cavity and is far away from the second valve cavity, the fourth valve cavity is communicated with the fourth valve cavity, the fourth valve cavity is communicated with a pressure regulating air port, and the pressure regulating air port is communicated with the secondary air outlet hole.

3. A safety air pump according to claim 2 wherein: the valve seat and the shell are surrounded by a fifth air cavity, the fifth air cavity is communicated with the fifth valve cavity, and the fifth air cavity is communicated with the connecting cavity.

4. A safety air pump according to claim 1 wherein: the third air cavity is also communicated with the connecting cavity through a second switch valve.

5. A safety air pump according to claim 4, characterized in that: and a sixth air cavity is further arranged between the valve seat and the shell in an enclosing manner, the third air cavity is communicated with the air inlet end of the second switch valve, the sixth air cavity is communicated with the air outlet end of the second switch valve, and the sixth air cavity is communicated with the connecting cavity.

6. A safety air pump according to any one of claims 1 to 5, wherein: the motor comprises a shell, a front end cover and a rear end cover are arranged on the shell, an air faucet is arranged on the rear end cover and communicated with an inner cavity of the shell, and a first air vent penetrating through the front end cover is formed in the front end cover.

7. A safety air pump according to claim 6, characterized in that: a first buffer cavity is defined between the air tap and the rear end cover, the air tap is communicated with the first buffer cavity, a second vent hole is formed in the rear end cover, one end of the second vent hole is communicated with the first buffer cavity, and the other end of the second vent hole is communicated with the inner cavity of the shell.

8. A safety air pump according to any one of claims 1 to 5, wherein: the drying tank is installed on the shell and comprises a first tank body and a second tank body which are connected in series, a second buffer cavity is formed by the first tank body and the shell, the fourth one-way valve is located in the second buffer cavity, a third buffer cavity is formed by the second tank body and the shell, and the third buffer cavity is communicated with the second air cavity through a high-pressure air port.

9. A safety air pump according to claim 8 wherein: the fourth check valve is an expanded fourth valve plate which can be far away from the second-stage rodless cavity, and the limiting plate can block the expanded fourth valve plate.

10. A safety air pump according to claim 8 wherein: the first check valve is a first valve plate, the first valve plate is arranged on the end wall of the primary piston, and the first valve plate is arranged close to the primary rodless cavity; the second check valve is a second valve plate which can be opened towards the direction far away from the primary rodless cavity; the third check valve is a third valve plate which can be opened towards the direction of the second-stage rodless cavity.