CN220101481U - Inflator pump - Google Patents

Abstract

The utility model discloses an inflator pump, which comprises a cover body, a power pump assembly, a valve plate and a one-way valve. The valve plate is in pressure connection between the cover body and the power pump assembly, and a plurality of air outlet through holes are formed in the valve plate; the check valve is connected with the valve plate and arranged on one side of the air outlet through hole close to the cover body, and the check valve limits air flow to flow from one side close to the power pump assembly to one side close to the cover body; the one-way valve comprises a plurality of first valve plates, each first valve plate corresponds to one air outlet via hole, and the aperture range of the air outlet via hole is set to be 0.5mm to 3mm. According to the technical scheme, the aperture of the air outlet through hole on the valve plate is limited to be in the range of 0.5-3 mm, so that sharp noise generated by the air outlet through hole due to too small is greatly eliminated, and the sound environment of the inflator pump in the use process is improved.

Description

Inflator pump

Technical Field

The utility model relates to the technical field of inflating devices, in particular to an inflator pump.

Background

In general, in the existing small air pump, a plurality of valves for controlling air paths are arranged on a valve plate, and the valves are often umbrella-shaped valves made of silica gel materials, which are called umbrella valves for short. Under the general condition, the umbrella valve can correspond a plurality of gas pockets that encircle the setting, can blow the valve block of umbrella valve when gas flow, is provided with following drawback so: on one hand, the corresponding plurality of air holes on the valve plate are too small in aperture, and when the air flow passes through the air holes, the friction of the air flow is large to generate huge sharp noise; on the other hand, the valve plate thickness of the umbrella valve is thinner, and the fluctuation angle of the valve plate is larger when the air flow passes through, so that larger noise can be generated when the umbrella valve flaps the valve plate.

Disclosure of Invention

The utility model mainly aims to provide an inflator pump, which aims to reduce noise generated by the inflator pump.

In order to achieve the above object, the present utility model provides an inflator comprising:

a cover body;

a power pump assembly;

the valve plate is in pressure connection between the cover body and the power pump assembly, and a plurality of air outlet through holes are formed in the valve plate;

the check valve is connected to the valve plate, is arranged on one side of the air outlet through hole close to the cover body, and limits air flow to one side of the cover body from one side close to the power pump assembly;

the one-way valve comprises a plurality of first valve plates, each first valve plate corresponds to one air outlet via hole, and the aperture range of the air outlet via hole is set to be 0.5mm to 3mm.

In an embodiment, a groove is formed on one side, close to the cover body, of the valve plate, a silica gel ring is embedded in the groove, the one-way valve is located in the middle of the silica gel ring, and the silica gel ring and the one-way valve are arranged in a split mode.

In an embodiment, a limiting block is arranged on the valve plate, a limiting groove matched with the limiting block is formed in one side of the one-way valve, a protruding block is formed on the other side of the one-way valve corresponding to the limiting groove, a plurality of separation strips connected with the protruding block are arranged on the one-way valve, and the one-way valve is separated into a plurality of first valve plates by the plurality of separation strips.

In an embodiment, a groove is formed on one side, close to the cover body, of the valve plate, a silica gel pad is embedded in the groove, and the one-way valve and the silica gel pad are integrally arranged.

In an embodiment, an umbrella valve is further arranged on the valve plate, a plurality of air return holes are formed in the circumferential direction of the umbrella valve, the umbrella valve is used for opening or closing the plurality of air return holes, and the umbrella valve limits air flow to the side close to the power pump assembly from the side close to the cover body.

In an embodiment, the pore diameter of the return air hole is smaller than the pore diameter of the outlet air via hole.

In an embodiment, a partition is disposed on a side of the cover body, which is close to the valve plate, and the partition divides a space between the cover body and the valve plate into an air outlet chamber and an air return chamber, the air outlet chamber is disposed corresponding to the air outlet via hole, the cover body is further provided with an air outlet hole, the air outlet hole is communicated with the air outlet chamber, and the air return chamber is disposed corresponding to the air return hole.

In an embodiment, the umbrella valve comprises a second valve plate and a valve rod connected with the second valve plate, wherein a limiting piece is arranged on the valve rod, and the limiting piece limits the umbrella valve on the valve plate.

In an embodiment, the thickness of the second valve sheet is smaller than the thickness of the first valve sheet.

In an embodiment, the power pump assembly comprises a leather cup support and a motor connecting seat which are connected, an air inlet is formed in the motor connecting seat, a plurality of air passing holes are formed in the leather cup support and the valve plate, the air passing holes are communicated with the air return cavity, and the air inlet is communicated with the air return cavity through the plurality of air passing holes to form an air inlet cavity.

According to the technical scheme, the aperture of the air outlet through hole on the valve plate is limited to be in the range of 0.5-3 mm, so that sharp noise generated by the air outlet through hole due to too small is greatly eliminated, and the sound environment of the inflator pump in the use process is improved.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.

FIG. 1 is an exploded view of an inflator of the present utility model;

FIG. 2 is a schematic view of an inflator of the present utility model;

FIG. 3 is a schematic illustration of the construction of the check valve, valve plate and power pump assembly, wherein the check valve is separated from the valve plate;

FIG. 4 is a schematic view of the structure of the check valve at a viewing angle;

FIG. 5 is a schematic view of a valve plate and a check valve according to another embodiment;

FIG. 6 is a schematic view of the valve plate in a view angle;

FIG. 7 is a schematic structural view of an umbrella valve;

FIG. 8 is a schematic view of the structure of the cover at a view angle;

FIG. 9 is a schematic view of the inflator with the motor removed from the inflator in a cross-sectional view.

Reference numerals illustrate:

reference numerals	Name of the name	Reference numerals	Name of the name
				100	Cover body	200	Power pump assembly
300	Valve plate	400	One-way valve
				500	Motor with a motor housing	600	Limiting strip
110	Partition piece	120	Air outlet chamber
				130	Return air chamber	140	Air outlet hole
210	Leather cup support	220	Motor connecting seat
				221	Air inlet hole	230	Air passing hole
240	Air inlet cavity	310	Air outlet via hole
				320	Groove	330	Silica gel ring
340	Limiting block	341	Round groove
				350	Silica gel pad	351	Round hole
360	Umbrella valve	361	Second valve plate
				362	Valve rod	3621	Limiting piece
370	Air return hole	410	First valve plate
				420	Limiting groove	421	Circular protrusion
430	Bump block	440	Dividing strip

The achievement of the objects, functional features and advantages of the present utility model will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It should be noted that, if directional indications (such as up, down, left, right, front, and rear … …) are included in the embodiments of the present utility model, the directional indications are merely used to explain the relative positional relationship, movement conditions, etc. between the components in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indications are correspondingly changed.

In addition, if there is a description of "first", "second", etc. in the embodiments of the present utility model, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, if the meaning of "and/or" is presented throughout this document, it is intended to include three schemes in parallel, taking "a and/or B" as an example, including a scheme, or B scheme, or a scheme where a and B meet simultaneously. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present utility model.

The utility model provides an inflator pump.

In an embodiment of the present utility model, as shown in FIGS. 1 and 2, the inflator includes a cover 100, a power pump assembly 200, a valve plate 300, and a check valve 400. The valve plate 300 is in pressure connection between the cover body 100 and the power pump assembly 200, and a plurality of air outlet through holes 310 are formed in the valve plate 300; check valve 400 is connected to valve plate 300, check valve 400 is disposed on a side of outlet port 310 adjacent to cover 100, check valve 400 defining an airflow from a side adjacent to power pump assembly 200 to a side adjacent to cover 100; the check valve 400 includes a plurality of first valve plates 410, each first valve plate 410 corresponds to one air outlet via hole 310, and the aperture range of the air outlet via hole 310 is set to 0.5mm to 3mm.

Specifically, the cover 100, the valve plate 300, and the power pump assembly 200 are sequentially connected, and the cover 100, the valve plate 300, and the power pump assembly 200 are limited together by a plurality of limit bars 600, and the check valve 400 is disposed between the cover 100 and the valve plate 300. The valve plate 300 is generally square plate-shaped, four corners of the valve plate 300 are arc-shaped, the cover 100 is correspondingly generally square plate-shaped, four corners of the cover 100 are arc-shaped, the power pump assembly 200 is generally square block-shaped, and four corners of the power pump assembly 200 are arc-shaped.

The valve plate 300 is provided with a plurality of air outlet through holes 310, and in this embodiment, the valve plate 300 is provided with four air outlet through holes 310, which is not limited to this embodiment, and the number of the air outlet through holes 310 may be less than four, and the number of the air outlet through holes 310 may be more than four. The air outlet vias 310 in this embodiment are distributed in two rows, and each row has two air outlet vias 310, and the air outlet vias 310 in the upper row and the lower row are in one-to-one correspondence.

Further, the check valve 400 includes a plurality of first valve plates 410, and each first valve plate 410 corresponds to one air outlet via hole 310, and in this embodiment, there are four air outlet via holes 310, so the check valve 400 corresponds to four first valve plates 410, the number of the first valve plates 410 is not limited to this embodiment, the number of the first valve plates 410 is the same as the number of the air outlet via holes 310, and the first valve plates 410 and the air outlet via holes 310 are in one-to-one correspondence.

In the prior art, the aperture of the air outlet via hole 310 is too small, so that the air flow can generate sharper noise when passing through the air outlet via hole 310, thus, the aperture of the air outlet via hole 310 is set in the range of 0.5mm to 3mm, and the noise generated when the air flow passes through the air outlet via hole 310 is reduced under the condition that the air flow transmission is not affected.

According to the technical scheme, the aperture of the air outlet through hole 310 on the valve plate 300 is limited to be in the range of 0.5mm to 3mm, so that sharp noise generated by the air outlet through hole 310 due to too small is greatly eliminated, and the sound environment of the inflator pump in the use process is improved.

In an embodiment, referring to fig. 1 and 3, a groove 320 is formed on a side of the valve plate 300, which is close to the cover 100, a silicone ring 330 is embedded in the groove 320, the one-way valve 400 is located in the middle of the silicone ring 330, and the silicone ring 330 and the one-way valve 400 are separately disposed.

Specifically, the valve plate 300 is formed with a groove 320, according to the above embodiment, the valve plate 300 is generally square, four corners of the valve plate 300 are arc-shaped, the shape of the groove 320 formed by the valve plate 300 near the cover 100 is similar to that of the valve plate 300, the shape of the silica gel ring 330 is generally adapted to that of the groove 320, the silica gel ring 330 is square, a square hole is formed in the center of the silica gel ring 330, and four corners of the silica gel ring 330 are arc-shaped, so that the silica gel ring 330 is embedded in the groove 320. The silica gel ring 330 is disposed between the valve plate 300 and the cover 100 to reduce vibration of the inflator, but more importantly, the silica gel pad 350 seals the valve plate 300 and the cover 100 to stabilize air pressure in the inflator.

It should be noted that, the check valve 400 is located in the silica gel ring 330, that is, the check valve 400 is disposed at the square hole position, in this embodiment, the check valve 400 and the silica gel ring 330 are separately disposed, so that the installation and replacement of the check valve 400 are simpler and more convenient.

In an embodiment, referring to fig. 3 and 4, a limiting block 340 is disposed on the valve plate 300, a limiting groove 420 matched with the limiting block 340 is disposed on one side of the check valve 400, a bump 430 is formed on the other side of the check valve 400 corresponding to the limiting groove 420, a plurality of separation strips 440 connected to the bump 430 are disposed on the check valve 400, and the plurality of separation strips 440 separate the check valve 400 into a plurality of first valve plates 410.

Specifically, the limiting block 340 is generally square, a circular groove 341 is provided in the middle of the limiting block 340, a circular protrusion 421 corresponding to the circular groove 341 is provided in the middle of the limiting groove 420 corresponding to the limiting block 340, when the limiting groove 420 is matched with the limiting block 340, the circular protrusion 421 is also matched with the circular groove 341, so that the mounting strength between the check valve 400 and the valve plate 300 is further enhanced, and when the air flow passing through the check valve 400 is avoided being excessively large, the check valve 400 is separated from the valve plate 300.

It should be further noted that, when the air flow passes through the check valve 400, the air flow blows the first valve plate 410 only, and does not blow the check valve plate 440, the check valve plate 400 is divided into a plurality of first valve plates 410 by the check valve plate 440, so that the area of each first valve plate 410 is smaller, and two adjacent sides of each valve plate, which are close to the bump 430, are fixed by the check valve plate 440, and thus the rising amplitude of the first valve plate 410 after being blown is limited, so that the sound of the first valve plate 410 beating the valve plate 300 is relatively smaller, compared with the prior art that the umbrella valve 360 is adopted, the noise generated when the first valve plate 410 beating the valve plate 300 is effectively reduced.

Additionally, referring to fig. 3, since four air outlet vias 310 are provided in the present embodiment, four first valve plates 410 are correspondingly provided, and therefore four dividing strips 440 are provided to divide the check valve 400 into four first valve plates 410, which is not limited to the number of dividing strips 440 in the present embodiment, the number of dividing strips 440 may be less than four, or may be more than four, and the number of dividing strips 440 only needs to be enough to just divide the check valve 400 into a plurality of first valve plates 410 opposite to the number of the air outlet vias 310.

In an embodiment, referring to fig. 5, a groove 320 is formed on a side of the valve plate 300 close to the cover 100, a silica gel pad 350 is embedded in the groove 320, and the check valve 400 and the silica gel pad 350 are integrally disposed.

Specifically, the valve plate 300 is formed with a groove 320, according to the above embodiment, the valve plate 300 is generally square, and four corners of the valve plate 300 are arc-shaped, and correspondingly, the shape of the groove 320 formed by the valve plate 300 near the cover 100 is similar to the shape of the valve plate 300, and the shape of the silica gel pad 350 is generally adapted to the shape of the groove 320. The silica gel pad 350 is square and four corners of the silica gel pad 350 are also arc-shaped, so that the silica gel pad 350 is embedded in the groove 320. The silica gel pad 350 is arranged between the valve plate 300 and the cover body 100, so that vibration of the inflator can be reduced, but more importantly, the silica gel pad 350 turns seal the valve plate 300 and the cover body 100, so that air pressure in the inflator can be kept stable.

Additionally, in this embodiment, referring to fig. 5, the silica gel pad 350 is provided with several round holes 351 at positions corresponding to the air outlet via holes 310, the plurality of first valve plates 410 are located at the round holes 351, the outer diameter of the first valve plates 410 is slightly smaller than the outer diameter of the round holes 351, and the plurality of first valve plates 410 and the silica gel pad 350 are integrally arranged, so that the structure of the check valve 400 is simplified, the installation of the check valve 400 is completed after the silica gel pad 350 is embedded, the installation step of the check valve 400 is omitted, and the installation of the inflator pump is greatly simplified.

In an embodiment, referring to fig. 5 and 6, an umbrella valve 360 is further disposed on the valve plate 300, a plurality of air return holes 370 are disposed along a circumferential direction of the umbrella valve 360, the umbrella valve 360 is used for opening or closing the plurality of air return holes 370, and the umbrella valve 360 defines an air flow from a side close to the cover 100 to a side close to the power pump assembly 200.

Specifically, the umbrella valve 360 in the present embodiment is used to limit the airflow from the side close to the cover 100 to the side close to the power pump assembly 200, so the valve plate of the umbrella valve 360 should be disposed on the side close to the power pump assembly 200 of the valve plate 300, and since the space between the valve plate 300 and the power pump assembly 200 is limited, the umbrella valve 360 cannot be replaced by the one-way valve 400 described in the above embodiment, and the provision of the umbrella valve 360 has the advantages of smaller volume and thinner thickness.

Further, in the present embodiment, a plurality of air return holes 370 are provided along the circumferential direction of each umbrella valve 360, as shown in fig. 5, six air return holes 370 are provided around each umbrella valve 360, which is not limited to the number of air return holes 370 around each umbrella valve 360 in the present embodiment, and the number of air return holes 370 around each umbrella valve 360 may be less than six or more than six.

In an embodiment, referring to fig. 5 and 6, the aperture of the air return hole 370 is smaller than the aperture of the air outlet via 310.

Specifically, the aperture of the air return hole 370 is set to be approximately in the range of 0.1mm to 0.3mm, and the aperture of the air outlet via 310 is in the range of 0.5mm to 3mm according to the above-described embodiment, so that the aperture of the air outlet via 310 is larger than the aperture of the air return hole 370. It should be noted that, the hole diameter of the air outlet via 310 is larger, so that sharp noise can be avoided, and the noise generated by the inflator pump in the utility model during operation can be reduced.

In an embodiment, referring to fig. 8, a partition member 110 is disposed on a side of the cover body 100 near the valve plate 300, the partition member 110 divides a space between the cover body 100 and the valve plate 300 into an air outlet chamber 120 and an air return chamber 130, the air outlet chamber 120 is disposed corresponding to the air outlet via hole 310, the cover body 100 is further provided with an air outlet hole 140, the air outlet hole 140 is communicated with the air outlet chamber 120, and the air return chamber 130 is disposed corresponding to the air return hole 370.

Specifically, the partition 110 divides the space between the cover 100 and the valve plate 300 into an air outlet chamber 120 and an air return chamber 130, wherein the air outlet chamber 120 is disposed corresponding to the check valve 400, and the air return chamber 130 is disposed corresponding to the plurality of air return holes 370.

Further, in an embodiment, referring to fig. 7, the umbrella valve 360 includes a second valve plate 361 and a valve rod 362 connected to the second valve plate 361, a limiting member 3621 is disposed on the valve rod 362, and the limiting member 3621 limits the umbrella valve 360 on the valve plate 300.

Specifically, the second valve plate 361 is located between the valve plate 300 and the power pump assembly 200, and the second valve plate 361 is used to restrict the flow of air flowing through the air return hole 370 from only one side of the valve plate 300 close to the cover 100 to one side of the valve plate 300 close to the power pump assembly 200. The valve rod 362 connected to the valve plate 300 is inserted into the opening provided in the valve plate 300, and the protruding stopper 3621 is provided on the valve rod 362 to limit the umbrella valve 360 to the valve plate 300.

In an embodiment, the thickness of the second valve plate 361 is smaller than the thickness of the first valve plate 410.

Specifically, the thickness of the first valve plate 410 is greater than that of the second valve plate 361, and when the air flows through the air outlet via hole 310 and the air return hole 370, the relief angle of the second valve plate 361 relative to the first valve plate 410 is greater, so that the impact force of the second valve plate 361 is stronger, and the sound of the second valve plate 361 beating on the valve plate 300 is greater. In view of this, the thickness of the first valve plate 410 of the check valve 400 is set to be larger, so that the first valve plate 410 is prevented from beating the valve plate 300 to cause larger noise, and the sound environment of the inflator is improved.

In an embodiment, referring to fig. 9, the power pump assembly 200 includes a cup holder 210 and a motor 500 connecting seat connected to each other, an air inlet 221 is provided on the motor 500 connecting seat, a plurality of air passing holes 230 are provided on the cup holder 210 and the valve plate 300, the air passing holes 230 are communicated with the air returning chamber 130, and an air inlet cavity 240 is formed between the air inlet 221 and the air returning chamber 130 through the plurality of air passing holes 230.

Specifically, the cup support is used for placing the cup, the motor 500 connecting seat is connected to the motor 500, the cup support and the motor 500 connecting seat are mutually abutted, wherein an air inlet 221 is formed in one side, close to the motor 500, of the motor 500 connecting seat, air is inflated into the inflator pump through the air inlet 221, and a plurality of air passing holes 230 are formed in the cup support and the valve plate 300, wherein the number of the air passing holes 230 can be one or two or more, and the number of the air passing holes can be more, and the number of the air passing holes is not particularly limited. More specifically, the air passing hole 230 of the valve plate 300 is communicated with the air returning chamber 130, the air inlet hole 221 forms an air inlet cavity 240 between the air returning chamber 130 and the air passing hole 230, and a specific air inlet flow path is shown by an arrow in fig. 9, and it should be noted that the air inlet flow path is only any air inlet flow path in the embodiment of the present utility model, and other air inlet flow paths are substantially the same as the air inlet flow path.

The foregoing description is only of the optional embodiments of the present utility model, and is not intended to limit the scope of the utility model, and all the equivalent structural changes made by the description of the present utility model and the accompanying drawings or the direct/indirect application in other related technical fields are included in the scope of the utility model.

Claims (10)

1. An inflator, comprising:

a cover (100);

a power pump assembly (200);

the valve plate (300) is in pressure connection between the cover body (100) and the power pump assembly (200), and a plurality of air outlet through holes (310) are formed in the valve plate (300);

a one-way valve (400), the one-way valve (400) being connected to the valve plate (300), the one-way valve (400) being disposed on a side of the outlet port (310) adjacent to the cover (100), the one-way valve (400) defining an airflow flowing from a side adjacent to the power pump assembly (200) to a side adjacent to the cover (100);

the check valve (400) comprises a plurality of first valve plates (410), each first valve plate (410) corresponds to one air outlet through hole (310), and the aperture range of the air outlet through hole (310) is set to be 0.5mm to 3mm.

2. The inflator pump according to claim 1, wherein a groove (320) is formed on a side of the valve plate (300) close to the cover body (100), a silicone ring (330) is embedded in the groove (320), the one-way valve (400) is located in the middle of the silicone ring (330), and the silicone ring (330) and the one-way valve (400) are separately arranged.

3. The inflator pump according to claim 2, wherein a stopper (340) is provided on the valve plate (300), a limit groove (420) matched with the stopper (340) is provided on one side of the check valve (400), a bump (430) is formed on the other side of the check valve (400) corresponding to the limit groove (420), a plurality of separation strips (440) connected with the bump (430) are provided on the check valve (400), and the plurality of separation strips (440) separate the check valve (400) into a plurality of first valve plates (410).

4. The inflator pump according to claim 1, wherein a groove (320) is formed on a side of the valve plate (300) close to the cover body (100), a silica gel pad (350) is embedded in the groove (320), and the one-way valve (400) and the silica gel pad (350) are integrally arranged.

5. The inflator according to claim 1, wherein an umbrella valve (360) is further provided on the valve plate (300), a plurality of air return holes (370) are provided along a circumferential direction of the umbrella valve (360), the umbrella valve (360) is configured to open or close the plurality of air return holes (370), and the umbrella valve (360) defines an air flow from a side close to the cover (100) to a side close to the power pump assembly (200).

6. The inflator of claim 5 wherein the aperture of the return air hole (370) is smaller than the aperture of the outlet air via (310).

7. The inflator pump according to claim 5, wherein a partition member (110) is provided on a side of the cover body (100) close to the valve plate (300), the partition member (110) divides a space between the cover body (100) and the valve plate (300) into an air outlet chamber (120) and an air return chamber (130), the air outlet chamber (120) is provided corresponding to the air outlet via hole (310), the cover body (100) is further provided with an air outlet hole (140), the air outlet hole (140) is communicated with the air outlet chamber (120), and the air return chamber (130) is provided corresponding to the air return hole (370).

8. The inflator of claim 5, wherein the umbrella valve (360) comprises a second valve plate (361) and a valve stem (362) connected to the second valve plate (361), a stopper (3621) is provided on the valve stem (362), and the stopper (3621) limits the umbrella valve (360) on the valve plate (300).

9. The inflator of claim 8 wherein the thickness of the second valve plate (361) is less than the thickness of the first valve plate (410).

10. The inflator pump of claim 7, wherein the power pump assembly (200) comprises a cup holder (210) and a motor connecting seat (220) which are connected, an air inlet hole (221) is formed in the motor connecting seat (220), a plurality of air passing holes (230) are formed in the cup holder (210) and the valve plate (300), the air passing holes (230) are communicated with the air return chamber (130), and an air inlet cavity (240) is formed between the air inlet hole (221) and the air return chamber (130) through the plurality of air passing holes (230).