TWI842482B - Three-stage variable pressure air pump - Google Patents

Abstract

An air pump includes a nozzle head, a cylinder, and a switch. The cylinder includes a connecting tube, a first cylinder, and a second cylinder. One end of the connecting tube is connected to the nozzle head, and the opposite end of the connecting tube is provided with a first piston. The first cylinder is sleeved outside the connecting tube, and a second piston is provided at the end of the first cylinder adjacent to the nozzle head. The interior of the first cylinder is divided into a first chamber. The second cylinder is sleeved outside the first cylinder, and the interior of the second cylinder is divided into a second chamber. The switch is sleeved outside the connecting tube and fixedly connected to the second cylinder. The switch can be switched to allow air to enter the nozzle head from the first chamber, the second chamber, or both at the same time. The air pump can switch between three different pressure output modes through the above structure.

Description

Three-stage transformer pump

The present invention mainly discloses an air pump, especially a three-stage transformer air pump.

Please refer to the patent case of "Variable Pressure Pump" of Taiwan Patent No. I645111, which is a variable pressure pump, which includes a first cylinder, a second cylinder, a first air pipe, a piston group, a connecting device and a deflation device. The first cylinder, the second cylinder and the first air pipe are coaxially arranged and can move axially relative to each other. The piston group can compress the air in the first cylinder and selectively compress the air in the second cylinder. The connecting device is arranged in the first cylinder and is suitable for connecting to the inflatable object. The deflation device includes a connecting member and a switching member, the connecting member is connected to the second cylinder and has a deflation hole connected to the second cylinder, and the switching member is connected to the connecting member and has an air guide groove that selectively connects to the deflation hole and connects to the outside.

The purpose of setting the variable pressure function of the air pump is to allow the user to fill the tire with gas with a large amount of gas first, and then increase the pressure output, so that the user can inflate the tire to the preset pressure in a more time-saving and labor-saving way. During the inflation process, the mode of the air pump must be switched. However, the above-mentioned air pump needs to use the method of turning the switch to switch the output mode of the air pump. The size of the switch is small and the location of the setting is also hidden, which is not convenient for the user to operate the mode switching, and the pressure output of the air pump can only be changed in two stages.

In view of the shortcomings of the above-mentioned known structure, the inventor has designed a three-stage transformer air pump, which can overcome all the shortcomings of the above-mentioned known structure.

The main purpose of the three-stage transformer air pump of the present invention is to provide an air pump including a nozzle head, a pump and a switch, wherein the pump includes a connecting pipe, a first cylinder, a second cylinder and a third cylinder, one end of the connecting pipe is connected to the nozzle head, a first valve ring is sleeved on the end of the connecting pipe opposite to the nozzle head, the first cylinder is sleeved outside the connecting pipe, the first valve ring contacts the inner periphery of the first cylinder, a second valve ring is sleeved on the end of the first cylinder adjacent to the nozzle head, and a third valve ring is sleeved on the end of the first cylinder opposite to the nozzle head. The first cylinder has an end cover, a first zone is arranged in the inner space of the first cylinder, the first zone is arranged on the side of the first valve ring opposite to the nozzle head, the first valve ring only supplies air flow from the first zone through the first valve ring into the inner space of the connecting pipe, the second cylinder sleeve is arranged outside the first cylinder, the second valve ring contacts the outer periphery of the connecting pipe and the inner periphery of the second cylinder, a piston is arranged at one end of the second cylinder opposite to the nozzle head, a second zone is arranged in the inner space of the second cylinder, the second zone is arranged on the side of the second valve ring adjacent to the nozzle head, the third cylinder sleeve is arranged outside the first cylinder, the second valve ring contacts the outer periphery of the connecting pipe and the inner periphery of the second cylinder, a piston is arranged at one end of the second cylinder opposite to the nozzle head, a second zone is arranged in the inner space of the second cylinder, the second zone is arranged on the side of the second valve ring adjacent to the nozzle head, and the third cylinder sleeve is arranged outside the second cylinder. The piston contacts the outer periphery of the first cylinder and the inner periphery of the third cylinder. A second end cover is sleeved on one end of the third cylinder adjacent to the nozzle head. The second end cover contacts the outer periphery of the second cylinder. A third zone is arranged in the inner space of the third cylinder. The third zone is arranged on the side of the piston opposite to the nozzle head. The end of the third cylinder opposite to the nozzle head is connected to the first end cover. The first end cover is provided with a connecting channel. The connecting channel connects the first zone and the third zone. The switch is sleeved outside the connecting pipe. The switch can rotate relative to the nozzle head and switch between the first and third zones. The switch is fixedly connected to one end of the second cylinder near the nozzle head, and the second cylinder can rotate synchronously with the switch. When the switch is in the first position, the switch can allow the air in the first zone and the second zone to pass through and enter the nozzle head. When the switch is in the second position, the switch can only allow the air in the second zone to pass through and enter the nozzle head. When the switch is in the third position, the switch can only allow the air in the first zone to pass through and enter the nozzle head. The pump can switch between three output modes with different pressures through the above structure.

The switch is provided with a switch, which is fixedly connected to the second cylinder. The switch is provided with a first channel, a second channel, a third channel and a fourth channel. When the switch is in the first position, the switch can allow the air in the first zone to pass through the first channel and enter the nozzle head, and the air in the second zone to pass through the second channel and enter the nozzle head. When the switch is in the second position, the switch can only allow the air in the second zone to pass through the third channel and enter the nozzle head. When the switch is in the third position, the switch can only allow the air in the first zone to pass through the fourth channel and enter the nozzle head.

The switch is provided with a connecting piece, which is sleeved on the connecting pipe and arranged in the second cylinder and abuts against the end of the switch opposite to the nozzle head. The connecting piece is provided with a first air hole and a second air hole. The first air hole is connected to the inner space of the connecting pipe. The outer periphery of the connecting piece is sleeved with a one-way valve ring, which contacts the inner periphery of the second cylinder. The one-way valve ring only allows air flow from the second area to enter the second air hole. When the switch is switched between the first position, the second position or the third position, the switch member rotates relative to the connecting member. When the switch is in the first position, the first channel connects the first air hole and the nozzle head, and the second channel connects the second air hole and the nozzle head. When the switch is in the second position, the third channel connects the second air hole and the nozzle head. When the switch is in the third position, the fourth channel connects the first air hole and the nozzle head.

The outer periphery of the switch is provided with a first mark, a second mark and a third mark. One end of the switch adjacent to the nozzle head is inserted into the nozzle head. The nozzle head is provided with a display slot. When the switch is in the first position, the first mark corresponds to the display slot, and the nozzle head shields the second mark and the third mark. When the switch is in the second position, the second mark corresponds to the display slot, and the nozzle head shields the first mark and the third mark. When the switch is in the third position, the third mark corresponds to the display slot, and the nozzle head shields the first mark and the second mark.

The outer periphery of the connecting pipe is provided with an annular concave portion and a first side hole and a second side hole are radially penetrated. The first side hole is connected to the inner space of the connecting pipe and the annular concave portion. The first air hole is connected to the inner space of the connecting pipe through the annular concave portion and the first side hole. The second side hole is adjacent to the first valve ring and is arranged on one side of the first valve ring adjacent to the nozzle head. The second side hole is connected to the inner space of the connecting pipe and the outer periphery of the connecting pipe.

The nozzle head is provided with an air inlet portion, one end of the connecting pipe is screwed to the air inlet portion in a plug-in manner, the switch is sleeved on the air inlet portion, the connecting pipe is provided with an annular convex portion along its radial outer periphery, the annular convex portion abuts against one end of the connecting member opposite to the switch, the annular concave portion and the first side hole are provided between the air inlet portion and the annular convex portion, the air inlet portion is provided with an air inlet hole along the radial direction of the connecting pipe, and the first channel, the second channel, the third channel and the fourth channel are respectively connected to the air inlet hole.

The connecting pipe includes a joint and a hollow part. One end of the joint is screwed to the air inlet part in a plug-in manner. The annular concave part, the first side hole and the annular convex part are arranged on the joint. The hollow part is screwed to the end of the joint opposite to the nozzle head in a sleeve manner and abuts against the annular convex part. The first valve ring and the second side hole are arranged on the hollow part and adjacent to the end of the hollow part opposite to the nozzle head.

Other objects, advantages and novelties of the present invention will become more apparent from the following detailed description and the accompanying drawings.

10: Pump

20: Wind mouth

21: Display slot

22: Air intake

221: Air intake

30: Pump

31: Connecting pipe

311: First valve ring

312: Ring concave part

313: First side hole

314: Second side hole

315: convex part

316:Connection

317:Hollow parts

32: First cylinder

321: Second valve ring

322: First end cap

323: District 1

324: Connecting Channels

33: Second cylinder

331: Piston

332: District 2

34: Third cylinder

341: Second end cap

342: District 3

40:Switch

41: Switching parts

411: First channel

412: Second channel

413: Third channel

414: Fourth channel

415: First Mark

416: Second mark

417: The third mark

418: First exhaust hole

419: Second exhaust hole

42: Connecting parts

421: First vent

422: Second air hole

423: One-way valve ring

Figure 1: A three-dimensional appearance diagram of the three-stage transformer air pump of the present invention.

Figure 2: A three-dimensional exploded view of the three-stage transformer air pump of the present invention.

Figure 3: A three-dimensional exploded view of the three-stage transformer air pump of the present invention from another perspective.

Figure 4: A cross-sectional structural diagram of the three-stage transformer pump switch of the present invention when the switch is in the first position.

Figure 5: is a diagram showing the action of the three-stage transformer pump switch of the present invention compressing the pump when it is in the first position.

Figure 6: A cross-sectional structural diagram of the three-stage transformer pump switch of the present invention when the switch is in the second position.

Figure 7: An action diagram of the three-stage transformer pump switch of the present invention compressing the pump when it is in the second position.

Figure 8: A cross-sectional structural diagram of the three-stage transformer pump switch of the present invention when the switch is in the third position.

Figure 9: is a diagram showing the action of the three-stage transformer pump switch of the present invention compressing the pump when it is in the third position.

The technology, means and effects adopted by the present invention are described in detail below with a preferred embodiment and accompanying drawings. This is for illustrative purposes only and is not limited to this structure in patent applications.

Referring to Figures 1 to 9, the three-dimensional appearance diagram, three-dimensional exploded diagram, cross-sectional structure diagram and action diagram of the three-stage transformer air pump of the present invention are shown. The air pump 10 of the present invention includes a nozzle head 20, a pump 30 and a switch 40; wherein: the pump 30 includes a connecting pipe 31, a first cylinder 32, a second cylinder 33 and a third cylinder 34, one end of the connecting pipe 31 is connected to the nozzle head 20, and a first valve ring 311 is sleeved on the end of the connecting pipe 31 opposite to the nozzle head 20, the first cylinder 32 is sleeved outside the connecting pipe 31, the first valve ring 311 contacts the inner periphery of the first cylinder 32, and the first cylinder 32 is sleeved outside the connecting pipe 31. The cylinder 32 is provided with a second valve ring 321 at one end adjacent to the nozzle head 20, and a first end cover 322 is provided at one end of the first cylinder 32 opposite to the nozzle head 20. The inner space of the first cylinder 32 is provided with a first zone 323, and the first zone 323 is provided on the side of the first valve ring 311 opposite to the nozzle head 20. The first valve ring 311 only allows air flow to enter the inner space of the connecting pipe 31 from the first zone 323 through the first valve ring 311. The second cylinder 33 is provided outside the first cylinder 32. The second valve ring 321 contacts the outer periphery of the communication pipe 31 and the inner periphery of the second cylinder 33. A piston 331 is provided at one end of the second cylinder 33 opposite to the nozzle head 20. A second area 332 is provided in the inner space of the second cylinder 33. The second area 332 is provided on the side of the second valve ring 321 adjacent to the nozzle head 20. The third cylinder 34 is sleeved outside the second cylinder 33. The piston 331 contacts the outer periphery of the first cylinder 32 and the inner periphery of the third cylinder 34. A second end cover 341 is sleeved near one end of the nozzle head 20, and the second end cover 341 contacts the outer periphery of the second cylinder 33. A third area 342 is provided in the inner space of the third cylinder 34, and the third area 342 is provided on the side of the piston 331 opposite to the nozzle head 20. The end of the third cylinder 34 opposite to the nozzle head 20 is connected to the first end cover 322, and the first end cover 322 is provided with a connecting channel 324, and the connecting channel 324 connects the first area 323 and the third area 342.

The switch 40 is sleeved outside the connecting pipe 31. The switch 40 can rotate relative to the nozzle head 20 and switch between the first position, the second position or the third position. The switch 40 is fixedly connected to one end of the second cylinder 33 adjacent to the nozzle head 20. The second cylinder 33 can rotate synchronously with the switch 40. When the switch 40 is in the first position, the switch 40 can allow the air in the first zone 323 and the second zone 332 to pass through and enter the nozzle head 20. When the switch 40 is in the second position, the switch 40 can only allow the air in the second zone 332 to pass through and enter the nozzle head 20. When the switch 40 is in the third position, the switch 40 can only allow the air in the first zone 323 to pass through and enter the nozzle head 20.

The switch 40 is provided with a switch 41, which is fixedly connected to the second cylinder 33. The switch 41 is provided with a first channel 411, a second channel 412, a third channel 413 and a fourth channel 414. When the switch 40 is in the first position, the switch 40 can allow the air in the first zone 323 to pass through the first channel 411 and enter the nozzle head 20, and the air in the second zone 332 to pass through the second channel 412 and enter the nozzle head 20. When the switch 40 is in the second position, the switch 40 can only allow the air in the second zone 332 to pass through the third channel 413 and enter the nozzle head 20. When the switch 40 is in the third position, the switch 40 can only allow the air in the first zone 323 to pass through the fourth channel 414 and enter the nozzle head 20.

The switch 40 is provided with a connecting member 42, which is sleeved on the connecting pipe 31 and arranged in the second cylinder 33 and abuts against the end of the switch 41 opposite to the nozzle head 20. The connecting member 42 is provided with a first air hole 421 and a second air hole 422. The first air hole 421 is connected to the inner space of the connecting pipe 31. The outer periphery of the connecting member 42 is sleeved with a one-way valve ring 423, which contacts the inner periphery of the second cylinder 33. The one-way valve ring 423 only allows air flow from the second zone 332 to enter the second air hole 422. When the switch 40 switches between the first position, the second position or the third position, the switch member 41 rotates relative to the connecting member 42. When the switch 40 is in the first position, the first channel 411 connects the first air hole 421 with the nozzle head 20, and the second channel 412 connects the second air hole 422 with the nozzle head 20. When the switch 40 is in the second position, the third channel 413 connects the second air hole 422 with the nozzle head 20. When the switch 40 is in the third position, the fourth channel 414 connects the first air hole 421 with the nozzle head 20.

The outer periphery of the switch 41 is provided with a first mark 415, a second mark 416 and a third mark 417. The end of the switch 41 adjacent to the nozzle head 20 is inserted into the nozzle head 20. The nozzle head 20 is provided with a display slot 21. When the switch 40 is in the first position, the first mark 415 corresponds to the display slot 21, and the nozzle head 20 covers the second mark 416 and the third mark 417. When the switch 40 is in the second position, the second mark 416 corresponds to the display slot 21, and the nozzle head 20 covers the first mark 415 and the third mark 417. When the switch 40 is in the third position, the third mark 417 corresponds to the display slot 21, and the nozzle head 20 covers the first mark 415 and the second mark 416.

The outer periphery of the connecting tube 31 is provided with an annular recess 312 and a first side hole 313 and a second side hole 314 are radially penetrated. The first side hole 313 connects the inner space of the connecting tube 31 and the annular recess 312. The first air hole 421 is connected to the inner space of the connecting tube 31 through the annular recess 312 and the first side hole 313. The second side hole 314 is adjacent to the first valve ring 311 and is arranged on a side of the first valve ring 311 adjacent to the nozzle head 20. The second side hole 314 connects the inner space of the connecting tube 31 and the outer periphery of the connecting tube 31.

The nozzle head 20 is provided with an air inlet 22, one end of the connecting pipe 31 is screwed to the air inlet 22 in a plug-in manner, the switch 41 is sleeved on the air inlet 22, the connecting pipe 31 is provided with an annular convex portion 315 along its radial outer periphery, the annular convex portion 315 abuts against one end of the connecting piece 42 opposite to the switch 41, the annular concave portion 312 and the first side hole 313 are provided between the air inlet 22 and the annular convex portion 315, the air inlet 22 is provided with an air inlet hole 221 along the radial direction of the connecting pipe 31, the first channel 411, the second channel 412, the third channel 413 and the fourth channel 414 are respectively connected to the air inlet hole 221.

The connecting pipe 31 includes a joint 316 and a hollow part 317. One end of the joint 316 is screwed to the air inlet 22 in a plug-in manner. The annular recess 312, the first side hole 313 and the annular protrusion 315 are arranged on the joint 316. The hollow part 317 is screwed to the end of the joint 316 opposite to the nozzle head 20 in a sleeve manner and abuts against the annular protrusion 315. The first valve ring 311 and the second side hole 314 are arranged on the hollow part 317 and adjacent to the end of the hollow part 317 opposite to the nozzle head 20.

The switch 41 is provided with a first exhaust hole 418 and a second exhaust hole 419. The first exhaust hole 418 and the second exhaust hole 419 are connected to the outside of the switch 40 at one end opposite to the connecting member 42. When the switch 40 is in the second position, the first exhaust hole 418 connects the first air hole 421 with the outside of the switch 40, and the air in the first area 323 is discharged to the outside of the switch 40 through the first exhaust hole 418. When the switch 40 is in the third position, the second exhaust hole 419 connects the second air hole 422 with the outside of the switch 40, and the air in the second area 332 is discharged to the outside of the switch 40 through the second exhaust hole 419.

The inner periphery of the piston 331 abutting against the first cylinder 32 and the outer periphery of the third cylinder 34 are respectively provided with a one-way valve structure, so that when the air pump 10 is extended, air can be sucked into the third cylinder 34 from the end of the third cylinder 34 adjacent to the nozzle head 20, and the air in the third cylinder 34 located on the side of the piston 331 opposite to the third area 342 will be sucked into the third area 342 through the one-way valve on the outer periphery of the piston 331, and the air in the second cylinder 33 located between the second valve ring 321 and the piston 331 will be sucked into the third area 342. The air in the third zone 342 is compressed and enters the second zone 332 through the second valve ring 321. When the air pump 10 is compressed, the air in the third zone 342 is compressed and enters the second cylinder 33 through the one-way valve on the inner periphery of the piston 331, and the other part enters the first zone 323 through the connecting passage 324. The first zone 323 is also compressed and enters the first air hole 421 through the first valve ring 311 and the hollow part 317. The air in the second zone 332 is compressed and enters the second air hole 422 through the one-way valve ring 423.

The pump 10 can switch between three output modes with different pressures through the above structure. When the pump 10 is in use, the nozzle head 20 can be connected to the air nozzle, and the user can switch the switch 40 to the first position, the second position or the third position according to the required tire pressure of the tire. Since the pump 10 can drive the switch 40 to move between the first position and the second position by directly rotating the second cylinder 33, it is easy to operate and can quickly switch modes.

Based on the above, it can be concluded that the present invention has the following advantages:

1. A three-stage transformer air pump according to the present invention, wherein the air pump comprises a nozzle head, a pump and a switch, wherein the pump comprises a connecting pipe, a first cylinder, a second cylinder and a third cylinder, wherein one end of the connecting pipe is connected to the nozzle head, and a first valve ring is sleeved on an end of the connecting pipe opposite to the nozzle head, wherein the first cylinder is sleeved outside the connecting pipe, wherein the first valve ring contacts the inner periphery of the first cylinder, wherein an end of the first cylinder adjacent to the nozzle head is sleeved with a second valve ring, wherein an end of the first cylinder opposite to the nozzle head is provided with a first end cover, wherein the The inner space of the first cylinder is provided with a first zone, and the first zone is provided on the side of the first valve ring opposite to the nozzle head. The first valve ring only supplies air flow from the first zone through the first valve ring into the inner space of the connecting pipe. The second cylinder sleeve is provided outside the first cylinder. The second valve ring contacts the outer periphery of the connecting pipe and the inner periphery of the second cylinder. A piston is provided at one end of the second cylinder opposite to the nozzle head. The inner space of the second cylinder is provided with a second zone, and the second zone is provided on the side of the second valve ring adjacent to the nozzle head. The third cylinder sleeve is provided outside the second cylinder. The piston contacts the outer periphery of the first cylinder and the inner periphery of the third cylinder. A second end cover is sleeved on one end of the third cylinder adjacent to the nozzle head. The second end cover contacts the outer periphery of the second cylinder. A third zone is arranged in the inner space of the third cylinder. The third zone is arranged on the side of the piston opposite to the nozzle head. The end of the third cylinder opposite to the nozzle head is connected to the first end cover. The first end cover is provided with a connecting channel. The connecting channel connects the first zone and the third zone. The switch is sleeved outside the connecting pipe. The switch can rotate relative to the nozzle head and be in a first position, The switch is fixedly connected to one end of the second cylinder near the nozzle head, and the second cylinder can rotate synchronously with the switch. When the switch is in the first position, the switch can allow the air in the first zone and the second zone to pass through and enter the nozzle head. When the switch is in the second position, the switch can only allow the air in the second zone to pass through and enter the nozzle head. When the switch is in the third position, the switch can only allow the air in the first zone to pass through and enter the nozzle head. The pump can switch between three output modes with different pressures through the above structure.

However, the above is only a preferred embodiment of the present invention and cannot be used to limit the scope of implementation of the present invention. Therefore, any changes in numerical values or replacement of equivalent components, or equivalent changes and modifications made according to the scope of the patent application of the present invention should still fall within the scope of the patent of the present invention.

10: Pump

20: Wind mouth

21: Display slot

30: Pump

33: Second cylinder

34: Third cylinder

341: Second end cap

415: First Mark

Claims (7)

A three-stage transformer air pump, comprising: a nozzle head; A pump, the pump includes a connecting pipe, a first cylinder, a second cylinder and a third cylinder, one end of the connecting pipe is connected to the nozzle head, a first valve ring is sleeved on the end of the connecting pipe opposite to the nozzle head, the first cylinder is sleeved outside the connecting pipe, the first valve ring contacts the inner periphery of the first cylinder, a second valve ring is sleeved on the end of the first cylinder adjacent to the nozzle head, a first end cover is provided on the end of the first cylinder opposite to the nozzle head, a first zone is provided in the internal space of the first cylinder, the first zone is provided on the side of the first valve ring opposite to the nozzle head, the first valve ring only allows air flow from the first zone to enter the internal space of the connecting pipe through the first valve ring, the second cylinder is sleeved outside the first cylinder, the second valve ring contacts the connecting pipe, and the second end cover is provided on the end of the first cylinder opposite to the nozzle head. The outer periphery of the through pipe and the inner periphery of the second cylinder, a piston is provided at one end of the second cylinder opposite to the nozzle head, a second zone is provided in the inner space of the second cylinder, the second zone is provided on the side of the second valve ring adjacent to the nozzle head, the third cylinder sleeve is provided outside the second cylinder, the piston contacts the outer periphery of the first cylinder and the inner periphery of the third cylinder, a second end cover is provided at one end of the third cylinder adjacent to the nozzle head, the second end cover contacts the outer periphery of the second cylinder, a third zone is provided in the inner space of the third cylinder, the third zone is provided on the side of the piston opposite to the nozzle head, the end of the third cylinder opposite to the nozzle head is connected to the first end cover, the first end cover is provided with a connecting channel, the connecting channel connects the first zone and the third zone; A switch is sleeved outside the communication pipe. The switch can rotate relative to the nozzle head and switch between the first position, the second position or the third position. The switch is fixedly connected to one end of the second cylinder adjacent to the nozzle head. The second cylinder can rotate synchronously with the switch. When the switch is in the first position, the switch can allow the air of the first zone and the second zone to pass through and enter the nozzle head. When the switch is in the second position, the switch can only allow the air of the second zone to pass through and enter the nozzle head. When the switch is in the third position, the switch can only allow the air of the first zone to pass through and enter the nozzle head. A three-stage transformer air pump as described in claim 1, wherein the switch is provided with a switch element, the switch element is fixedly connected to the second cylinder, the switch element is provided with a first channel, a second channel, a third channel and a fourth channel, when the switch is in the first position, the switch can allow the air of the first zone to pass through the first channel and enter the nozzle head, and the air of the second zone to pass through the second channel and enter the nozzle head, when the switch is in the second position, the switch can only allow the air of the second zone to pass through the third channel and enter the nozzle head, when the switch is in the third position, the switch can only allow the air of the first zone to pass through the fourth channel and enter the nozzle head. A three-stage transformer air pump as described in claim 2, wherein the switch is provided with a connecting piece, the connecting piece is sleeved on the connecting pipe and is arranged in the second cylinder and abuts against the end of the switch opposite to the nozzle head, the connecting piece is provided with a first air hole and a second air hole, the first air hole is connected to the internal space of the connecting pipe, the outer peripheral sleeve of the connecting piece is provided with a one-way valve ring, the one-way valve ring contacts the inner periphery of the second cylinder, and the one-way valve ring only supplies air flow from the first The second zone enters the second air hole. When the switch is switched between the first position, the second position or the third position, the switching member rotates relative to the connecting member. When the switch is in the first position, the first channel connects the first air hole and the nozzle head, and the second channel connects the second air hole and the nozzle head. When the switch is in the second position, the third channel connects the second air hole and the nozzle head. When the switch is in the third position, the fourth channel connects the first air hole and the nozzle head. A three-stage transformer air pump as described in claim 2, wherein a first mark, a second mark and a third mark are provided on the outer periphery of the switch, one end of the switch adjacent to the nozzle head is inserted into the nozzle head, and the nozzle head is provided with a display slot. When the switch is in the first position, the first mark corresponds to the display slot, and the nozzle head covers the second mark and the third mark. When the switch is in the second position, the second mark corresponds to the display slot, and the nozzle head covers the first mark and the third mark. When the switch is in the third position, the third mark corresponds to the display slot, and the nozzle head covers the first mark and the second mark. A three-stage transformer air pump as described in claim 3, wherein an annular recess is provided on the outer periphery of the connecting tube and a first side hole and a second side hole are radially penetrated, the first side hole is connected to the inner space of the connecting tube and the annular recess, the first air hole is connected to the inner space of the connecting tube through the annular recess and the first side hole, the second side hole is adjacent to the first valve ring and is provided on a side of the first valve ring adjacent to the nozzle head, the second side hole is connected to the inner space of the connecting tube and the outer periphery of the connecting tube. A three-stage transformer air pump as described in claim 5, wherein the nozzle head is convexly provided with an air inlet portion, one end of the connecting pipe is screwed to the air inlet portion in a plug-in manner, the switching element is sleeved on the air inlet portion, the connecting pipe is provided with an annular convex portion along its radial outer periphery, the annular convex portion abuts against an end of the connecting element opposite to the switching element, the annular recess and the first side hole are provided between the air inlet portion and the annular convex portion, the air inlet portion is provided with an air inlet hole along the radial direction of the connecting pipe, and the first channel, the second channel, the third channel and the fourth channel are respectively connected to the air inlet hole. A three-stage transformer air pump as described in claim 6, wherein the connecting pipe includes a connector and a hollow part, one end of the connector is screwed to the air inlet part in a plug-in manner, the annular recess, the first side hole and the annular protrusion are arranged on the connector, the hollow part is screwed to the end of the connector opposite to the nozzle head in a sleeve manner and abuts against the annular protrusion, the first valve ring and the second side hole are arranged on the hollow part and adjacent to the end of the hollow part opposite to the nozzle head.

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