阅读说明：本技术 具有充气及抽气功能的大气量打气筒 (large-air-volume inflator with inflation and air-extraction functions ) 是由 王罗平 于 2018-05-29 设计创作，主要内容包括：一种具有充气及抽气功能的大气量打气筒,包含一个具有一个组装孔的筒座、一个可升降的安装在该筒座上的活塞单元,以及一个控气机构。该活塞单元与该筒座相配合界定出位于该组装孔上方的一个第一气室、一个第二气室。该控气机构包括一个可转动地安装在该组装孔内的阀杆,该阀杆具有两个充气道及两个抽气道,该控气机构还包括一个安装在所述充气道内的充气阀组,以及一个安装在所述抽气道内的抽气阀组。前述结构的配合,可以在该打气筒与一个充气对象连接时,避免与该充气对象连接的一个管件随着该活塞单元上下移动,以达到防止在使用过程中该管件脱落,以及该管件阻碍操作的目的。(The utility model provides a big tolerance inflater with aerify and bleed function, contains a cylinder base that has an equipment hole, the piston unit of installing on this cylinder base of a liftable to and a accuse gas mechanism. The piston unit and the cylinder seat are matched to define a first air chamber and a second air chamber which are positioned above the assembling hole. The air control mechanism comprises a valve rod which is rotatably arranged in the assembly hole, the valve rod is provided with two air charging channels and two air pumping channels, the air control mechanism also comprises an air charging valve group arranged in the air charging channels and an air pumping valve group arranged in the air pumping channels. The cooperation of aforementioned structure can be when this inflater is connected with an object of aerifing, avoids a pipe fitting of being connected with this object of aerifing to reciprocate along with this piston unit to reach and prevent this pipe fitting drop in the use, and this pipe fitting hinders the purpose of operation.)

1. an atmospheric inflator adapted to inflate and deflate an inflatable object, comprising: the piston unit comprises a piston seat arranged in the cylinder seat, and the piston seat and the cylinder seat are matched to define a first air chamber and a second air chamber; the method is characterized in that:

The cylinder seat comprises an assembling hole positioned below the first air chamber and the second air chamber; the inflator also comprises an air control mechanism, the air control mechanism comprises a valve rod which is rotatably arranged in the assembling hole, the valve rod is provided with a first air charging passage, a second air charging passage, a first air pumping passage and a second air pumping passage, the air control mechanism also comprises an air charging valve group which is arranged in the first air charging passage and the second air charging passage of the valve rod, and an air pumping valve group which is arranged in the first air pumping passage and the second air pumping passage; when the inflator is in an inflation mode, external air enters the inflation object through the first inflation channel and the second inflation channel by matching of the inflation valve group, when the valve rod is rotated to enable the inflator to be switched to an air extraction mode, and through matching of the air extraction valve group, air in the inflation object is exhausted through the first air extraction channel and the second air extraction channel.

2. the large air pump according to claim 1, wherein: the first inflation valve group is provided with two first inflation valves which are respectively arranged in the first inflation holes and two second inflation valves which are respectively arranged in the second inflation holes; when the inflator is located in the inflation mode and the piston unit is pressed downwards, one of the first inflation valves is opened to allow external gas to enter the second air chamber through the first inflation channel, and meanwhile, one of the second inflation valves is opened to allow gas located in the first air chamber to enter the inflation object through the second inflation channel.

3. the large air pump according to claim 1 or claim 2, wherein: the first air exhaust passage is provided with two first air exhaust holes which are respectively communicated with the first air chamber and the second air chamber, the second air exhaust passage is provided with two second air exhaust holes which are respectively communicated with the first air chamber and the second air chamber, the air exhaust valve group is provided with two first air exhaust valves which are respectively arranged in the first air exhaust holes, and two second air exhaust valves which are respectively arranged in the second air exhaust holes; when the inflator is in the air pumping mode and the piston unit is pressed downwards, one of the first air pumping valves is opened to allow the gas inside the inflatable object to enter the second air chamber through the first air pumping passage, and simultaneously one of the second air pumping valves is opened to allow the gas inside the first air chamber to be pumped out through the second air pumping passage; when the piston unit moves upwards, the other one of the first air extraction valves is opened to allow the gas in the inflation object to enter the first air chamber through the first air extraction passage, and the other one of the second air extraction valves is opened to allow the gas in the second air chamber to be extracted through the second air extraction passage.

4. The large air pump according to claim 3, wherein: the valve rod is also provided with a first air exchange passage and a second air exchange passage, the air control mechanism further comprises a ventilation valve group arranged in the first air exchange passage and the second air exchange passage, when the inflator is positioned in a ventilation mode, air in the first air chamber and the second air chamber can be ventilated through the first air exchange passage under the control of the ventilation valve group when the piston unit moves upwards, when the piston unit is pressed downwards, external air enters the second air chamber through the first air exchange passage, and the air in the first air chamber enters the inflated object through the second air exchange passage.

5. The large air pump according to claim 4, wherein: the first ventilation duct has a first ventilation hole communicated with the first air chamber in the ventilation mode and two second ventilation holes communicated with the second air chamber in the ventilation mode, the second ventilation duct has a third ventilation hole communicated with the first air chamber in the ventilation mode, the ventilation valve group has a first ventilation valve installed in the first ventilation hole, two second ventilation valves installed in the second ventilation holes, respectively, and a third ventilation valve installed in the third ventilation hole; when the inflator is located in the ventilation mode and the piston unit moves upwards, external air pushes the first ventilation valve to enter the first air chamber, meanwhile, air located in the second air chamber pushes one of the second ventilation valves to be discharged from the first ventilation channel, when the piston unit is pressed downwards, air located in the first air chamber pushes the third ventilation valve to enter the inflatable object through the second ventilation channel, meanwhile, external air enters the first ventilation channel, and enters the second air chamber after the other one of the second ventilation valves is opened.

6. The large air pump according to claim 5, wherein: the cylinder seat also comprises an inner cylinder wall, an outer cylinder wall surrounding the outer part of the inner cylinder wall, an assembly annular wall defining the assembly hole and connected below the inner cylinder wall and the outer cylinder wall, and an end cover covering the upper parts of the inner cylinder wall and the outer cylinder wall, the piston unit also comprises a handle linked and combined with the piston seat, the piston seat is provided with a piston body movably and airtightly clamped between the inner cylinder wall and the outer cylinder wall, and an extension pipe part protruding upwards from the piston body and combined with the handle, the first air chamber is positioned between the inner cylinder wall and the outer cylinder wall and positioned below the piston body, the second air chamber is provided with a first space defined by the inner cylinder wall, a second space positioned between the inner cylinder wall and the outer cylinder wall and positioned above the piston body, and a third space positioned between the inner cylinder wall and the extension pipe part and communicated with the first space, the assembling annular wall is also provided with a through hole group, and the through hole group is provided with two first through holes communicated with the first air chamber and two second through holes communicated with the first space of the second air chamber; when the inflator is in the inflation mode, the first air inflation channel and the second air inflation channel are communicated with the through hole group, when the inflator is in the air extraction mode, the first air extraction channel and the second air extraction channel are communicated with the through hole group, and when the inflator is in the air exchange mode, the first air exchange channel and the second air exchange channel are communicated with the through hole group.

7. the large air pump according to claim 1, wherein: the cylinder seat also comprises an inner cylinder wall, an outer cylinder wall surrounding the outer part of the inner cylinder wall, an assembly annular wall defining the assembly hole and connected below the inner cylinder wall and the outer cylinder wall, and an end cover covering the upper parts of the inner cylinder wall and the outer cylinder wall, the piston unit also comprises a handle linked and combined with the piston seat, the piston seat is provided with a piston body movably and airtightly clamped between the inner cylinder wall and the outer cylinder wall, and an extension pipe part protruding upwards from the piston body and combined with the handle, the first air chamber is positioned between the inner cylinder wall and the outer cylinder wall and positioned below the piston body, the second air chamber is provided with a first space defined by the inner cylinder wall, a second space positioned between the inner cylinder wall and the outer cylinder wall and positioned above the piston body, and a third space positioned between the inner cylinder wall and the extension pipe part and communicated with the first space, the assembling annular wall is also provided with a through hole group, and the through hole group is provided with two first through holes communicated with the first air chamber and two second through holes communicated with the first space of the second air chamber; when the inflator is in the inflation mode, the first air inflation channel and the second air inflation channel are communicated with the through hole group, and when the inflator is in the air extraction mode, the first air extraction channel and the second air extraction channel are communicated with the through hole group.

Technical Field

The present invention relates to a pump, and more particularly to a large air pump which can be switched between an inflation mode and a deflation mode according to the use requirement.

Background

Referring to fig. 1 and 2, a CN201610830U utility model discloses an inflator 1 capable of generating a large amount of air, the inflator 1 includes a cylinder base 11 defining a closed space 10, a piston 12 located in the closed space 10, a plurality of air control valves 13 installed in the piston 12, and a handle unit 14 driving the piston 12 to move up and down in the closed space 10, the piston 12 divides the closed space 10 into an upper air chamber 101 and a lower air chamber 102, and has two valve chambers 121, each valve chamber 121 has an upper valve port 122 communicated with the upper air chamber 101, and a lower valve port 123 communicated with the lower air chamber 102. The gas control valve 13 is respectively installed in the upper valve port 122 and the lower valve port 123, and can open and close the corresponding upper valve port 122 and the corresponding lower valve port 123.

the handle unit 14 has a handle 141, an inner tube 142 and an outer tube 143 coaxially sleeved and installed between the piston 12 and the handle 141, the inner tube 142 defines a first channel 144 communicating with one of the valve chambers 121, the outer tube 143 and the inner tube 142 cooperate to define a second channel 145 communicating with the other valve chamber 121, the handle 141 has two holding portions 146 protruding toward opposite sides, a first through hole 147 communicating with the first channel 144, and a second through hole 148 communicating with the second channel 145.

When the conventional air pump 1 is operated to inflate, a pipe (not shown) is connected between an object to be inflated and the second opening 148, and then the handle unit 14 is pushed to move up and down. As shown by the solid arrows in fig. 2, when the handle unit 14 moves upward, the gas in the upper chamber 101 flows to the second port 148 through the second channel 145 by the cooperation of the gas control valve 13, and the external gas enters the first channel 144 through the first port 147 and finally enters the lower chamber 102 for storage. As shown by the arrows in phantom lines in fig. 2, when the piston 12 is moved downward by the handle unit 14, the gas in the lower chamber 102 enters the second channel 145 and flows out through the second port 148, and the gas entering through the first port 147 enters the upper chamber 101 through the first channel 144 for storage. If the tube is installed at the first opening 147, the air inside the inflatable object is reversely pumped out for the purpose of air pumping.

Although the above-mentioned utility model can produce the effect of inflation and air exhaust, the pipe connected to the inflation object is installed on the first opening 147 or the second opening 148 of the handle unit 14, so that the pipe can move along with the movement when the handle unit 14 moves up and down. The structure not only can cause the problem that the pipe is difficult and inconvenient to operate, but also can cause the problems that the pipe is not stably jointed and falls off in the using process because the pipe is often pulled.

Disclosure of Invention

The present invention is directed to a large air pump with inflation and deflation functions that overcomes at least one of the disadvantages of the background art.

The large-air-volume inflator is suitable for inflating and exhausting an inflation object and comprises a cylinder seat, a piston unit and an air control mechanism which is arranged on the cylinder seat and is adjacent to the lower part. The cylinder seat comprises an assembling hole, the piston unit comprises a piston seat which is arranged in the cylinder seat and can move in a reciprocating mode, and the piston seat and the cylinder seat are matched to define a first air chamber and a second air chamber which are located above the assembling hole. The air control mechanism comprises a valve rod which is rotatably arranged in the assembly hole, the valve rod is provided with a first air charging channel, a second air charging channel, a first air pumping channel and a second air pumping channel, the air control mechanism also comprises an air charging valve group arranged in the first air charging channel and the second air charging channel of the valve rod, and an air pumping valve group arranged in the first air pumping channel and the second air pumping channel; when the inflator is in an inflation mode, external air enters the inflation object through the first inflation channel and the second inflation channel by matching of the inflation valve group, and when the inflator is switched to an air extraction mode, the air in the inflation object is exhausted through the first air extraction channel and the second air extraction channel by matching of the air extraction valve group.

The invention relates to a large-air-volume inflator, wherein a first inflation channel is provided with two first inflation holes which are respectively communicated with a first air chamber and a second air chamber, a second inflation channel is provided with two second inflation holes which are respectively communicated with the first air chamber and the second air chamber, an inflation valve group is provided with two first inflation valves which are respectively arranged in the first inflation holes, and two second inflation valves which are respectively arranged in the second inflation holes; when the inflator is located in the inflation mode and the piston unit is pressed downwards, one of the first inflation valves is opened to allow external gas to enter the second air chamber through the first inflation channel, and meanwhile, one of the second inflation valves is opened to allow gas located in the first air chamber to enter the inflation object through the second inflation channel.

The large-air-volume inflator is characterized in that the first air pumping channel is provided with two first air pumping holes which are respectively communicated with the first air chamber and the second air chamber, the second air pumping channel is provided with two second air pumping holes which are respectively communicated with the first air chamber and the second air chamber, the air pumping valve group is provided with two first air pumping valves which are respectively arranged in the first air pumping holes, and two second air pumping valves which are respectively arranged in the second air pumping holes; when the inflator is in the air pumping mode and the piston unit is pressed downwards, one of the first air pumping valves is opened to allow the gas inside the inflatable object to enter the second air chamber through the first air pumping passage, and simultaneously one of the second air pumping valves is opened to allow the gas inside the first air chamber to be pumped out through the second air pumping passage; when the piston unit moves upwards, the other one of the first air extraction valves is opened to allow the gas in the inflation object to enter the first air chamber through the first air extraction passage, and the other one of the second air extraction valves is opened to allow the gas in the second air chamber to be extracted through the second air extraction passage.

The invention relates to a large-air-volume inflator, wherein the valve rod is also provided with a first air exchange passage and a second air exchange passage, the air control mechanism also comprises a ventilation valve group arranged in the first air exchange passage and the second air exchange passage, when the inflator is positioned in a ventilation mode, air in the first air chamber and the second air chamber can be ventilated through the first air exchange passage under the control of the ventilation valve group when the piston unit moves upwards, when the piston unit is pressed downwards, external air enters the second air chamber through the first air exchange passage, and the air in the first air chamber enters an inflated object through the second air exchange passage.

The invention relates to a large-air-volume inflator, wherein a first scavenging duct is provided with a first scavenging hole communicated with a first air chamber in a scavenging mode and two second scavenging holes communicated with a second air chamber in the scavenging mode, a second scavenging duct is provided with a third scavenging hole communicated with the first air chamber in the scavenging mode, a scavenging valve group is provided with a first scavenging valve arranged in the first scavenging hole, two second scavenging valves respectively arranged in the second scavenging holes and a third scavenging valve arranged in the third scavenging hole; when the inflator is located in the ventilation mode and the piston unit moves upwards, external air pushes the first ventilation valve to enter the first air chamber, meanwhile, air located in the second air chamber pushes one of the second ventilation valves to be discharged from the first ventilation channel, when the piston unit is pressed downwards, air located in the first air chamber pushes the third ventilation valve to enter the inflatable object through the second ventilation channel, meanwhile, external air enters the first ventilation channel, and enters the second air chamber after the other one of the second ventilation valves is opened.

The invention relates to a large-air-volume inflator, wherein the cylinder base also comprises an inner cylinder wall, an outer cylinder wall surrounding the outer part of the inner cylinder wall, an assembly ring wall defining the assembly hole and connected below the inner cylinder wall and the outer cylinder wall, and an end cover covering the upper parts of the inner cylinder wall and the outer cylinder wall, the piston unit also comprises a handle linked with the piston base, the piston base is provided with a piston body movably and airtightly clamped between the inner cylinder wall and the outer cylinder wall, and an extension pipe part protruding upwards from the piston body and combined with the handle, the first air chamber is positioned between the inner cylinder wall and the outer cylinder wall and positioned below the piston body, the second air chamber is provided with a first space defined by the inner cylinder wall, and a second space positioned between the inner cylinder wall and the outer cylinder wall and positioned above the piston body, A third space between the inner cylinder wall and the extension pipe and communicated with the first space, and at least one communication hole on the extension pipe and communicated with the second space and the third space, wherein the assembly annular wall is also provided with a through hole group, and the through hole group is provided with two first through holes communicated with the first air chamber and two second through holes communicated with the first space of the second air chamber; when the inflator is in the inflation mode, the first air inflation channel and the second air inflation channel are communicated with the through hole group, when the inflator is in the air extraction mode, the first air extraction channel and the second air extraction channel are communicated with the through hole group, and when the inflator is in the air exchange mode, the first air exchange channel and the second air exchange channel are communicated with the through hole group.

The invention has the following effects: the air control mechanism is arranged at the position below the cylinder seat and is irrelevant to the operation of the piston unit, so that the invention not only can achieve the purposes of inflating and exhausting air with large air quantity, but also can prevent a pipe fitting connecting the inflator and the inflating object from moving up and down along with the piston unit.

Drawings

Other features and effects of the present invention will become apparent from the following detailed description of the embodiments with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of CN201610830U utility model;

Fig. 2 is a combined sectional view of the utility model;

Fig. 3 is a partial exploded perspective view of the pump according to the present invention, illustrating the pump in relation to a tube;

fig. 4 is a fragmentary assembled cross-sectional view of the first embodiment, illustrating the pump and tube in relative relation;

fig. 5 is a view similar to fig. 4, with the pump in a charging mode and a piston unit of the pump depressed;

Fig. 6 is a view similar to fig. 4, with the pump also in the inflation mode but with the piston unit pulled up;

Fig. 7 is a view similar to fig. 4, with the pump in a pumping mode and the piston unit depressed;

Fig. 8 is a view similar to fig. 4, with the pump also in the pumping mode but with the piston unit pulled up;

Fig. 9 is a partial exploded perspective view of a second embodiment of the pump of the present invention, illustrating the relative relationship of the pump and the tube;

Fig. 10 is a fragmentary assembled cross-sectional view of the second embodiment, the pump in a scavenging mode and the piston unit depressed;

Fig. 11 is a view similar to fig. 10, the pump also being in the air exchange mode but with the piston unit pulled up.

Detailed Description

Before the present invention is described in detail, it should be noted that in the following description, similar components are denoted by the same reference numerals.

Referring to fig. 3, 4 and 5, a first embodiment of the pump according to the present invention is manually operated to fill or withdraw gas from an inflating object (not shown) such as: inflatable boats, inflatable cushions, inflatable beds, etc., the invention is not limited in its application to the foregoing examples. The pump is connected to the object to be inflated by means of a tube 9 and comprises: a cylinder base 2, a piston unit 3 and a gas control mechanism 4 which are arranged on the cylinder base 2.

the cartridge holder 2 comprises an upright hollow inner cartridge wall 21, an outer cartridge wall 22 coaxial with and surrounding the outside of the inner cartridge wall 21, an assembly ring wall 23 arranged around a rotation axis 20, two pedals 24 protruding from the outer cartridge wall 22 on opposite sides and adjacent to the bottom end, and an end cap 25 covering the inner cartridge wall 21 and the outer cartridge wall 22, the end cap 25 having a centrally located holding hole 251. The assembly ring wall 23 is interposed between the pedals 24 and has an inner surface 232 defining an assembly hole 231, and a through hole group 230, the through hole group 230 having two first through holes 233 and two second through holes 234.

The piston unit 3 includes a piston seat 31 partially extending into the cylinder seat 2, and a handle 32 coupled to the piston seat 31, the piston seat 31 has a piston body 311 airtightly clamped between the inner cylinder wall 21 and the outer cylinder wall 22, and an extension pipe 312 integrally connected to the piston body 311 and extending through the supporting hole 251 to be coupled to the handle 32, the piston seat 31 and the cylinder seat 2 cooperate to define a first air chamber 33 and a second air chamber 34. The first air chamber 33 is disposed between the inner cylinder wall 21 and the outer cylinder wall 22, is located below the piston body 311, and is communicated with the first through hole 233. The second air chamber 34 has a first space 341 between the inner cylindrical wall 21 and communicating with the second through hole 234, a second space 342 between the extension pipe 312 and the outer cylindrical wall 22, a third space 343 between the extension pipe 312 and the inner cylindrical wall 21 and communicating with the first space 341, and a plurality of communication holes 344 provided in the extension pipe 312 and communicating with the second space 342 and the third space 343.

The air control mechanism 4 includes a valve rod 41, the valve rod 41 has a central portion 411 rotatably installed in the assembling hole 231, and a pulling portion 412 protruding from the central portion 411 to a radial outer end, the central portion 411 has a first end face 413, a second end face 414, a first air charging passage 43, a second air charging passage 44, a first air pumping passage 45, and a second air pumping passage 40. The first air charging passage 43 and the second air charging passage 44 are linearly corresponding to each other, and the first air pumping passage 45 and the second air pumping passage 40 are also linearly corresponding to each other.

The first gas-filling duct 43 has a gas inlet 431 adjacent to the first end face 413 and two first gas-filling holes 432 respectively communicating with one of the first through holes 233 and one of the second through holes 234, the second gas-filling duct 44 has a gas outlet 441 adjacent to the second end face 414 and two second gas-filling holes 442 respectively communicating with the other of the first through holes 233 and the other of the second through holes 234. The first pumping channel 45 has a pumping inlet 451 adjacent to the second end face 414 and two first pumping holes 452, and the second pumping channel 40 has a pumping outlet 401 adjacent to the first end face 413 and two second pumping holes 402.

The air control mechanism 4 further includes an air valve set 46 installed in the first air inflation channel 43 and the second air inflation channel 44, and an air valve set 47 installed in the first air pumping channel 45 and the second air pumping channel 40, the air valve set 46 has two first air valves 461 installed in the first air inflation holes 432, and two second air valves 462 installed in the second air inflation holes 442, the air valve set 47 has two first air valves 471 installed in the first air pumping holes 452, and two second air valves 472 installed in the second air pumping holes 402.

referring to fig. 4, 5 and 6, in the inflator of this embodiment, in an inflation mode, the first inflation channel 43 and the second inflation channel 44 are located above and adjacent to each other, and are communicated with the first space 341 of the first air chamber 33 and the second air chamber 34 through the through hole set 230. As shown in FIG. 5, when the piston unit 3 is pressed, the gas in the first air chamber 33 pushes the corresponding second inflation valve 462 open, and enters the tube 9 through the second inflation channel 44, and finally enters the inflatable object. On the other hand, the volume of the second space 342 is increased, and the gas in the first space 341 is pumped to the second space 342, so that the gas in the first space 341 is pumped to generate a suction force, so that the external gas can push the corresponding first inflation valve 461 through the first inflation channel 43 and enter the first space 341.

as shown in fig. 6, when the piston unit 3 is pulled up, the volume of the first air chamber 33 increases and thus generates a suction force, and at this time, external air enters the first air inflation channel 43 and pushes open the corresponding first air inflation valve 461 to enter the first air chamber 33. On the other hand, the piston body 311 moving upward compresses the second space 342 of the second air chamber 34, so that the gas therein flows through the third space 343 via the communication hole 344 and finally flows into the first space 341, and when the pressure in the first space 341 increases, the gas pushes the corresponding second inflation valve 462 and finally enters the inflatable object from the second inflation channel 44 via the tube 9. That is, the present embodiment can inflate during the process of moving up or pressing down the piston unit 3, and the purpose of inflating with large air volume is achieved through the cooperation of the above structures.

Referring to fig. 4, 7 and 8, when the air pump of this embodiment is to be switched from the inflation mode of fig. 5 and 6 to an air suction mode of fig. 7 and 8, the valve rod 41 is rotated to make the first air suction passage 45 and the second air suction passage 40 face upward to correspond to the through hole set 230, and the inflation object is also connected to the valve rod 41 through the pipe 9. When the piston unit 3 is pressed, the gas in the first air chamber 33 pushes the corresponding second air pumping valve 472 and is exhausted through the second air pumping channel 40, meanwhile, the volume of the second space 342 is increased, and after the suction force is generated inside the first space 341, the gas in the first air pumping channel 45 is pumped into the first space 341 of the second air chamber 34.

When the piston unit 3 is pulled up, a suction force is generated in the first air chamber 33, and at this time, the gas in the inflation object pushes the corresponding second air-extracting valve 471 away through the first air-extracting passage 45 and enters the first air chamber 33. On the other hand, the piston body 311 moving upward also reduces the volume of the second space 342, so as to pump the gas into the first space 341, finally push open the corresponding second pumping valve 472, and pump the gas into the second pumping channel 40 for discharge. Thus, the gas in the inflatable object can be rapidly pumped out by pulling and pressing.

Referring to fig. 9, 10 and 11, a second embodiment of the pump according to the present invention, similar in structure to the first embodiment, also has the function of inflating and ventilating at atmospheric pressure. The difference lies in that: a ventilation function is added, that is, when the inflator is switched to a ventilation mode, the ventilation function can be performed only when the piston unit 3 is pulled up, and the high-pressure air charging effect is achieved when the piston unit 3 is pressed down.

To achieve the above-mentioned object, the central portion 411 of the valve stem 41 of the present embodiment further has a first scavenging passage 49, and a second scavenging passage 49 'laterally corresponding to the first scavenging passage 49, the first scavenging passage 49 having a first scavenging hole 491 corresponding to one of the first through holes 233, and two second scavenging holes 492 respectively corresponding to the second through holes 234, the second scavenging passage 49' having a third scavenging hole 493 corresponding to the other of the first through holes 233. The air control mechanism 4 further comprises a scavenging valve set 48, the scavenging valve set 48 having a first scavenging valve 481 mounted in the first scavenging hole 491, two second scavenging valves 482 mounted in said second scavenging holes 492, respectively, and a third scavenging valve 483 mounted in the third scavenging hole 493.

When the pump is in the ventilation mode, the first ventilation duct 49 and the second ventilation duct 49 'are facing upwards, and when the piston unit 3 is pressed down, the gas in the first air chamber 33 pushes the third ventilation valve 483 away and pushes the gas through the second ventilation duct 49' towards the object to be inflated, and at the same time, the second air chamber 34 generates a suction force due to the increased volume, and thus opens one of the second ventilation valves 482, so that the gas enters the second air chamber 34.

When the piston unit 3 is pulled up to increase the volume of the first air chamber 33, the external air pushes the first gas exchange valve 481 to enter the first air chamber 33, and the air in the second air chamber 34 is compressed to push the other one of the second gas exchange valves 482 away, i.e. in the gas exchange mode, the piston unit 3 moves up to exchange air, and only the piston unit 3 is pressed down to have a high-pressure air charging function.

As can be seen from the above description, the air control mechanism 4 is disposed at a position adjacent to and below the cylinder base 2, and the valve rod 41, the inflation valve set 46, the air exhaust valve set 47, and the air exhaust valve set 48 are matched to achieve the purposes of inflation, air exhaust, and air exhaust at a large air volume, and the above structure can also prevent the connected pipe 9 from moving up and down along with the handle 32, so as to achieve the purposes of easy and convenient operation, and preventing the pipe 9 from falling off.