Mini electric high-pressure inflator pump

Abstract

The mini electric high-pressure inflator pump comprises a machine core, the machine core comprises a driving assembly, a piston cylinder, a piston rod, an exhaust valve assembly and an inflation cylinder, the first end of the piston rod is connected with the driving assembly, the second end of the piston rod is movably inserted into the piston cylinder, and the piston cylinder is provided with a first exhaust port; the exhaust valve assembly is arranged at a first exhaust port of the piston cylinder in an openable and closable mode. An inflation cavity is formed in the inflation cylinder, the piston cylinder is inserted into the inflation cavity, the inflation cylinder is provided with a second exhaust port, and the second exhaust port communicates with the first exhaust port through the inflation cavity; according to the utility model, a heat dissipation function can be realized without additionally arranging a fan.

Description

Technical Field

[0001] The utility model relates to the field of air pumps, in particular to a mini electric high-pressure air pump. Background Art

[0002] With the rapid development of technology, inflatable products are becoming increasingly popular among consumers due to their portability and ease of storage. The general inflation process involves pushing gas through the inflatable product into the air tube, which then inflates the object.

[0003] An inflatable product currently includes a housing assembly, a fixed bracket, a gas transmission mechanism, a control circuit board, and an air pressure sensor, all housed within the housing assembly. The fixed bracket defines an air transmission channel and an air pressure channel connected to the air transmission channel. The air transmission end of the gas transmission mechanism is connected to the air transmission channel. The control circuit board is electrically connected to the gas transmission mechanism. The air pressure sensor is used to detect the air pressure in the air pressure channel. The air transmission channel of this inflatable product extends parallel to the direction of movement of the piston in the gas transmission mechanism, resulting in a relatively high height. Furthermore, this inflatable product requires fins for heat dissipation, which increases the number of components, assembly complexity, and production costs. Utility Model Content

[0004] The purpose of the utility model is to provide a mini electric high-pressure air pump which can perform a heat dissipation function without the need for an additional fan.

[0005] In order to achieve the above-mentioned purpose, the mini electric high-pressure air pump provided by the utility model includes a movement, which includes a drive assembly, a piston cylinder, a piston rod, an exhaust valve assembly and an inflation cylinder. The first end of the piston rod is connected to the drive assembly, and the second end of the piston rod is movably inserted into the piston cylinder. The piston cylinder is provided with a first exhaust port, and the exhaust valve assembly can be opened and closed at the first exhaust port of the piston cylinder; an inflation chamber is provided in the inflation cylinder, the piston cylinder is inserted into the inflation chamber, and the inflation cylinder is provided with a second exhaust port, which is connected to the first exhaust port through the inflation chamber.

[0006] It can be seen from the above scheme that by inserting the piston cylinder into the inflation chamber, during inflation, the gas discharged from the first exhaust port is first filled into the inflation chamber and then discharged from the second exhaust port. During this process, the gas can take away part of the heat generated by the piston cylinder, thereby playing a heat dissipation function; the utility model does not require an additional heat dissipation fan, has a streamlined structure and reduces the number of parts, simplifies the assembly process and saves production costs.

[0007] A further solution is that the second exhaust port is staggered with the first exhaust port in the axial direction of the piston cylinder, and the exhaust direction of the second exhaust port can be parallel to or intersect with the exhaust direction of the first exhaust port.

[0008] It can be seen from the above scheme that through the above setting, the gas discharged from the first exhaust port first moves a certain distance around the periphery of the piston cylinder before reaching the second exhaust port and being discharged outward, which is beneficial to avoid the gas discharged from the first exhaust port being directly discharged from the second arrangement port, thereby ensuring the heat dissipation effect.

[0009] A further solution is that the piston cylinder is inserted into the middle of the inflation chamber, an annular channel is formed between the outer wall of the piston cylinder and the inner wall of the inflation chamber, and the first exhaust port is connected to the second exhaust port through the annular channel.

[0010] It can be seen from the above scheme that the above arrangement ensures that the gas can be filled into the entire annular channel, which is beneficial to increase the contact area between the gas and the outer wall of the piston cylinder and further improve the heat dissipation effect.

[0011] A further solution is that the movement also includes an air pressure detection component for detecting the air pressure in the inflation cavity.

[0012] A further solution is that the inflation cylinder includes an inflation cylinder body and an inflation base; a second exhaust port is provided at the first end of the inflation cylinder body, a first mounting hole is provided at the second end of the inflation cylinder body, the piston cylinder is arranged in the first mounting hole, a second mounting hole is provided at the third end of the inflation cylinder body, the inflation base is connected to the third end of the inflation cylinder body and communicated with the second mounting hole, and the air pressure detection component is arranged on the inflation base.

[0013] A further solution is that the piston cylinder is provided with a first fixed column on the outside of the first exhaust port; the exhaust valve assembly includes a swinging member, an elastic member and a plug, the plug can be opened and closed to block the first exhaust port, the first end of the swinging member is connected to the first fixed column, the second end of the swinging member can swing around its first end, and the elastic member elastically abuts between the plug and the second end of the swinging member.

[0014] It can be seen from the above scheme that through the above setting, under normal circumstances, the plug automatically closes the first exhaust port under the action of the elastic member; during inflation, the gas in the piston cylinder is compressed to a certain pressure to form high-pressure gas, and then pushes the plug to move outward and compresses the spring or pushes the swinging member to swing outward to open the first exhaust port, thereby discharging the high-pressure gas.

[0015] A further solution is that the movement also includes a mounting seat, the piston cylinder is arranged on one end of the mounting seat, the other end of the mounting seat is provided with a mounting portion, and the drive assembly is provided on the mounting portion; the drive assembly includes a power source, a driving wheel and a driven wheel, the driving wheel is arranged on the driving end of the power source, the driving wheel is engaged with the driven wheel, and the diameter of the driving wheel is smaller than the diameter of the driven wheel; a second fixed column is eccentrically provided on the driven wheel, and the first end of the piston rod is rotatably connected to the second fixed column.

[0016] As can be seen from the above scheme, through the above setting, the driving wheel and the driven wheel adopt a reduction design to ensure that when a small-sized motor is used as a power source, even if its torque is limited, the piston cylinder can generate sufficiently high pressure.

[0017] A further solution is that the second end of the piston rod is provided with an annular mounting groove, a sealing ring and a plurality of ventilation grooves, the sealing ring is sleeved in the annular mounting groove, the plurality of ventilation grooves are arranged along the circumference of the piston rod, and the ventilation grooves extend along the axial direction of the piston rod and are connected with the annular mounting groove; the sealing ring includes a connecting ring portion, an outer ring portion and an inner ring portion, the outer ring portion and the inner ring portion are coaxially arranged on the same side of the connecting ring portion, the outer wall of the outer ring portion protrudes from the outer wall of the first end of the piston rod, and an avoidance groove is formed between the outer ring portion and the inner ring portion, and the outer ring portion can shrink or expand along its radial direction.

[0018] It can be seen from the above scheme that through the above arrangement, when inflating, the piston rod drives the sealing ring to move toward the first exhaust port. At this time, the outer ring part can expand outward to ensure a sealed connection between the sealing ring and the inner wall of the piston cylinder; when the piston rod returns, the outer ring part can return to its initial state or shrink and deform inward, so that the sealing ring does not contact the inner wall of the piston cylinder, which is beneficial to reduce friction, increase the return speed of the piston rod, and thus improve efficiency.

[0019] A further solution is that the movement also includes a control circuit board and a power supply module, the control circuit board is connected to the mounting seat, and the control circuit board is electrically connected to the power supply module and the drive assembly respectively.

[0020] A further solution is that the mini electric high-pressure air pump also includes a shell and a cover body, the shell includes a first side wall and four second side walls, the four second side walls are arranged end to end on the first side wall, and an accommodating cavity is formed between the first side wall and the four second side walls. The movement is arranged in the accommodating cavity, and the accommodating cavity has an opening facing away from the first side wall, and the cover body is detachably arranged in the opening. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural diagram of an embodiment of the present utility model.

[0022] Figure 2 It is an exploded view of an embodiment of the present utility model.

[0023] Figure 3 It is a cross-sectional view of an embodiment of the present utility model.

[0024] Figure 4 yes Figure 3 Enlarged view of point A in the middle.

[0025] Figure 5 It is an exploded view of the movement in the embodiment of the present utility model.

[0026] Figure 6It is a structural diagram of the mounting base in an embodiment of the present utility model.

[0027] Figure 7 It is a structural diagram of the inflation cylinder in an embodiment of the present utility model.

[0028] Figure 8 It is an exploded view of the piston rod and the sealing ring in the embodiment of the present utility model.

[0029] Figure 9 It is a structural diagram of the shell in the embodiment of the present utility model.

[0030] Figure 10 It is a structural diagram of the battery box in the embodiment of the present utility model.

[0031] Figure 11 It is a structural diagram of the cover body in the embodiment of the present utility model.

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0033] See also Figure 1 and Figure 2 , and combined with Figure 9 The mini electric high-pressure air pump provided in this embodiment includes a shell 1, a movement 2 and a cover 3.

[0034] The housing 1 is a semi-enclosed rectangular structure, comprising a first sidewall 11 and four second sidewalls 12. The four second sidewalls 12 are attached end-to-end to the first sidewall 11, and the first sidewall 11 is provided with a plurality of holes for mounting buttons. A receiving cavity is formed between the first sidewall 11 and the four second sidewalls 12. The receiving cavity has an opening facing away from the first sidewall 11. The movement 2 is disposed within the receiving cavity, and the cover 3 is removably positioned within the opening.

[0035] See also Figures 3 to 5 The movement 2 includes a mounting seat 21, a driving assembly 22, a piston rod 23, an exhaust valve assembly 24 and an air charging cylinder 25.

[0036] A mounting portion 211 is provided at a first end of the mounting seat 21 . The mounting portion 211 is configured as a flat plate-shaped structure, and the driving assembly 22 is disposed on the mounting portion 211 .

[0037] The drive assembly 22 includes a power source 221, a driving pulley 222, and a driven pulley 223. The power source 221 is disposed on a first side of the mounting portion 211 and is preferably a brushless motor. The drive end of the power source 221 extends through the mounting portion 211 to a second side thereof. The driving pulley 222 is sleeved onto the drive end of the power source 221 and meshes with the driven pulley 223. When the power source 221 is activated, the driving pulley 222 drives the driven pulley 223 to rotate about its axis. The diameter of the driving pulley 222 is smaller than that of the driven pulley 223 to achieve a speed reduction design. This ensures that even when a compact brushless motor is used as the power source 221, the piston cylinder 212 can generate sufficient high pressure, even with limited torque. A second fixing post 2231 is provided on the driven pulley 223, eccentrically disposed relative to the driven pulley 223. The first end of the piston rod 23 is rotatably connected to the second fixing post 2231 via a bearing.

[0038] The second end of the mounting base 21 is provided with a piston cylinder 212. The piston cylinder 212 is integrally formed with the mounting portion 211, or the piston cylinder 212 and the mounting portion 211 are fixedly connected by screws, which is not limited here. The first end of the piston rod 23 is connected to the drive assembly 22, and the second end of the piston rod 23 is movably inserted into the piston cylinder 212. When the drive assembly 22 drives the driven wheel 223 to rotate, the second fixing column 2231 drives the piston rod 23 to move back and forth along the axial direction of the piston cylinder 212. The piston cylinder 212 is provided with a first exhaust port 2121 at the end away from the mounting portion 211. The extension direction of the first exhaust port 2121 is parallel to the axial direction of the piston cylinder 212. The exhaust valve assembly 24 is arranged at the first exhaust port 2121 of the piston cylinder 212 so as to be openable and closable.

[0039] During inflation, the piston rod 23 moves toward the first exhaust port 2121. Due to the setting of the exhaust valve assembly 24, the gas in the piston cylinder 212 is compressed. When the pressure of the compressed gas reaches a certain standard, high-pressure gas is formed. The high-pressure gas can push open the exhaust valve assembly 24, so that the first exhaust port 2121 opens, and the high-pressure gas is discharged from the piston cylinder 212; when the piston rod 23 moves away from the first exhaust port 2121, the exhaust valve assembly 24 automatically closes the first exhaust port 2121, and ordinary gas can enter the piston cylinder 212 from the gap between the piston rod 23 and the piston cylinder 212.

[0040] In order to install the exhaust valve assembly 24, the piston cylinder 212 is provided with a first fixing column 2122 on the outside of the first exhaust port 2121, and the first fixing column 2122 extends axially along the first exhaust port 2121. The exhaust valve assembly 24 includes a swinging member 241, an elastic member 242 and a plug 243. The first end of the swinging member 241 is connected to the first fixing column 2122 by a screw, and the second end of the swinging member 241 extends toward the first exhaust port 2121, and the second end of the swinging member 241 can swing around its first end. The plug 243 is arranged corresponding to the first exhaust port 2121 to block the first exhaust port 2121. The elastic member 242 elastically abuts between the plug 243 and the second end of the swinging member 241, so that the plug 243 can open and close the first exhaust port 2121.

[0041] In order to ensure that the plug 243 will not be offset radially along the first exhaust port 2121, the piston cylinder 212 of this embodiment is provided with a plurality of arc-shaped stop plates 2123 on the outer periphery of the first exhaust port 2121. The plurality of arc-shaped stop plates 2123 are arranged along the circumference of the first exhaust port 2121 and form a circle. The circle is coaxially arranged with the first exhaust port 2121, and the plug 243 is arranged within the circle.

[0042] An inflation chamber 251 is provided in the inflation cylinder 25, and one end of the piston cylinder 212 is inserted into the inflation chamber 251. The inflation cylinder 25 is provided with a second exhaust port 252, and the second exhaust port 252 is connected to the first exhaust port 2121 through the inflation chamber 251. The high-pressure gas discharged from the first exhaust port 2121 is first filled into the inflation chamber 251 and then discharged from the second exhaust port 252. During this process, the high-pressure gas can take away part of the heat generated by the piston cylinder 212, thereby playing a heat dissipation role.

[0043] In the axial direction of the piston cylinder 212, the second exhaust port 252 is staggered with the first exhaust port 2121, and the exhaust direction of the second exhaust port 252 can be parallel to or intersect with the exhaust direction of the first exhaust port 2121. Preferably, the exhaust direction of the second exhaust port 252 is perpendicular to the exhaust direction of the first exhaust port 2121.

[0044] Furthermore, one end of the piston cylinder 212 is inserted into the middle of the inflation chamber 251 , and an annular channel is formed between the outer wall of the piston cylinder 212 and the inner wall of the inflation chamber 251 , and the first exhaust port 2121 is connected to the second exhaust port 252 through the annular channel.

[0045] During inflation, after the high-pressure gas is discharged from the first exhaust port 2121, it is first filled into the annular channel so that the high-pressure gas can fully contact the peripheral wall of the piston cylinder 212, and then the high-pressure gas is discharged from the second exhaust port 252, which is beneficial to further improve the heat dissipation effect.

[0046] In this embodiment, the movement 2 also includes an air pressure detection assembly 26 for detecting the air pressure within the plenum chamber. Specifically, a second exhaust port 252 is disposed at the first end of the plenum chamber 251, and the air pressure detection assembly 26 is disposed at the second end of the plenum chamber 251. The air pressure detection assembly 26 includes a detection circuit board 261 and an air pressure sensor disposed on the detection circuit board 261.

[0047] Combine Figure 3 、 Figures 5 to 7 The inflatable cylinder 25 includes an inflatable cylinder body 253 and an inflatable base 254. The inflatable cylinder body 253 is configured as a three-way structure. The first end of the inflatable cylinder body 253 defines a second exhaust port 252. The second end of the inflatable cylinder body 253 defines a first mounting hole 2531, in which the piston cylinder 212 is disposed. The inflatable base 254 is connected to the third end of the inflatable cylinder body 253, and the interior of the inflatable base 254 is in communication with the second mounting hole 2532.

[0048] The air pressure detection assembly 26 is mounted on the inflatable base 254. Specifically, the inflatable base 254 defines a first through-hole 2541 and a detection cavity 2542. The detection cavity 2542 communicates with the inflatable cavity 251 through the first through-hole 2541. A detection circuit board 261 is connected to the detection cavity 2542. The air pressure detection assembly 26 also includes a sealing ring 262, which is sealed between the detection circuit board 261 and the periphery of the detection cavity 2542. The pressure sensor is mounted within the sealing ring 262 and extends into the detection cavity 2542.

[0049] See also Figure 8 , and combined with Figures 3 to 5 The second end of the piston rod 23 is provided with an annular mounting groove 231, a sealing ring 232, and a plurality of vent grooves 233. The plurality of vent grooves 233 are evenly spaced along the circumference of the piston rod 23. The vent grooves 233 extend axially along the piston rod 23 and communicate with the annular mounting groove 231. The vent grooves 233 also extend through the end wall of the second end of the piston rod 23.

[0050] The sealing ring 232 is mounted within the annular mounting groove 231. The sealing ring 232 comprises a connecting ring portion 2321, an outer ring portion 2322, and an inner ring portion 2323. The outer ring portion 2322 and the inner ring portion 2323 are coaxially arranged on the same side of the connecting ring portion 2321. The outer wall of the outer ring portion 2322 extends axially and obliquely, protruding above the outer wall of the first end of the piston rod 23. A relief groove 2324 is formed between the outer ring portion 2322 and the inner ring portion 2323, with a notch extending toward the second end of the piston rod 23. The sealing ring 232 is made of an elastic material such as rubber or silicone, and the outer ring portion 2322 can contract or expand radially.

[0051] When the piston rod 23 moves toward the first exhaust port 2121, under the action of air pressure, the outer ring portion 2322 expands outward, ensuring that the sealing ring 232 is sealed and connected to the inner wall of the piston cylinder 212; when the piston rod 23 moves away from the first exhaust port 2121, the outer ring portion 2322 returns to its initial state or contracts inward, ensuring that the sealing ring 232 and the inner wall of the piston cylinder 212 are properly fitted, so as to reduce friction and allow gas to enter the piston cylinder 212 through the gap between the sealing ring 232 and the piston cylinder 212.

[0052] Combine Figure 2 、 Figure 3 and Figure 5 The movement 2 of this embodiment also includes a control circuit board 27 and a power supply module. The mounting base 21 and the inflatable base 254 are both connected to the control circuit board 27 via connecting posts and screws. The power supply module is housed within the housing 1 and includes a battery holder 28 and a battery (not shown) housed therein. The control circuit board 27 is electrically connected to the power supply module and the drive assembly 22. A power button and plus / minus buttons are provided on the control circuit board 27.

[0053] See also Figures 9 to 11 , and combined with Figure 3 The shell 1 is provided with a card slot 121 on each of the four second side walls 12, and the card slot 121 extends along the transverse direction of the first side wall 11, which is parallel to the cover body 3; the shell 1 is provided with a limiting groove 122 on each of the two opposite second side walls 12, and the limiting groove 122 extends along the longitudinal direction of the first side wall 11, which is perpendicular to the cover body 3.

[0054] The battery holder 28 is provided with limit bars 281 on both sides thereof, and the limit bars 281 protrude from the outer wall of the battery holder 28. The limit bars 281 are used to cooperate with the limit grooves 122 to fix and limit the position of the battery holder 28.

[0055] The cover 3 includes a main body 31 and four flanges 32 . The four flanges 32 are connected end to end around the main body 31 . Buckles 321 are provided on the outer side walls of the flanges 32 . The buckles 321 are provided in a one-to-one correspondence with the slots 121 .

[0056] When the cover 3 is connected to the housing 1 , the flange 32 is inserted into the housing 1 , and the buckle 321 is embedded in the slot 121 , thereby achieving a detachable connection between the cover 3 and the housing 1 .

[0057] The body 31 defines a second through-hole 311, which communicates with the second exhaust port 252 of the inflation cylinder 25. To prevent the ingress of dust and debris, the cover 3 is connected to a sealing cap 33. One end of the sealing cap 33 is movably connected to the body 31, and a second end of the sealing cap 33 is detachably connected to the second exhaust port 252 or the second through-hole 311.

[0058] In summary, it can be seen that the utility model inserts the piston cylinder 212 into the inflation chamber 251. During inflation, the gas discharged from the first exhaust port 2121 is first filled into the inflation chamber 251 and then discharged from the second exhaust port 252. During this process, the gas can take away part of the heat generated by the piston cylinder 212, thereby playing a heat dissipation function. The utility model does not require an additional cooling fan, has a streamlined structure, reduces the number of parts, simplifies the assembly process, and saves production costs.

[0059] Finally, it should be emphasized that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A mini electric high-pressure air pump comprising a movement, the movement comprising a drive assembly, a piston cylinder, a piston rod, and an exhaust valve assembly, wherein a first end of the piston rod is connected to the drive assembly, a second end of the piston rod is movably inserted into the piston cylinder, the piston cylinder having a first exhaust port, and the exhaust valve assembly is openably and closably disposed at the first exhaust port of the piston cylinder, characterized in that: The mini electric high-pressure air pump also includes an air filling cylinder, which is provided with an air filling chamber. The piston cylinder is inserted into the air filling chamber. The air filling cylinder is provided with a second exhaust port, which is connected to the first exhaust port through the air filling chamber.

2. The mini electric high-pressure air pump according to claim 1, characterized in that: In the axial direction of the piston cylinder, the second exhaust port is staggered with the first exhaust port, and the exhaust direction of the second exhaust port can be parallel to or intersect with the exhaust direction of the first exhaust port.

3. The mini electric high-pressure air pump according to claim 2, characterized in that: The piston cylinder is inserted into the middle of the inflation cavity. An annular channel is formed between the outer wall of the piston cylinder and the inner wall of the inflation cavity. The first exhaust port is connected to the second exhaust port through the annular channel.

4. The mini electric high-pressure air pump according to claim 1, characterized in that: The movement also includes an air pressure detection component for detecting the air pressure in the inflation cavity.

5. The mini electric high-pressure air pump according to claim 4, characterized in that: The inflation cylinder comprises an inflation cylinder body and an inflation base; The first end of the inflatable cylinder body is provided with the second exhaust port, the second end of the inflatable cylinder body is provided with a first mounting hole, the piston cylinder is arranged in the first mounting hole, the third end of the inflatable cylinder body is provided with a second mounting hole, the inflatable base is connected to the third end of the inflatable cylinder body and is connected to the second mounting hole, and the air pressure detection component is arranged on the inflatable base.

6. The mini electric high-pressure air pump according to claim 1, characterized in that: The piston cylinder is provided with a first fixing column on the outer side of the first exhaust port; The exhaust valve assembly includes a swinging member, an elastic member and a plug. The plug can be opened and closed to block the first exhaust port. The first end of the swinging member is connected to the first fixed column. The second end of the swinging member can swing around its first end. The elastic member elastically abuts between the plug and the second end of the swinging member.

7. The mini electric high-pressure air pump according to claim 1, characterized in that: The movement further comprises a mounting seat, the piston cylinder is arranged on one end of the mounting seat, the other end of the mounting seat is provided with a mounting portion, and the drive assembly is arranged on the mounting portion; The driving assembly includes a power source, a driving wheel and a driven wheel. The driving wheel is arranged on the driving end of the power source, and the driving wheel is engaged with the driven wheel. The diameter of the driving wheel is smaller than the diameter of the driven wheel. A second fixed column is eccentrically provided on the driven wheel, and the first end of the piston rod is rotatably connected to the second fixed column.

8. The mini electric high-pressure air pump according to claim 1, characterized in that: The second end of the piston rod is provided with an annular mounting groove, a sealing ring and a plurality of ventilation grooves, the sealing ring is sleeved in the annular mounting groove, the plurality of ventilation grooves are arranged along the circumference of the piston rod, and the ventilation grooves extend along the axial direction of the piston rod and are communicated with the annular mounting groove; The sealing ring includes a connecting ring portion, an outer ring portion and an inner ring portion. The outer ring portion and the inner ring portion are coaxially arranged on the same side of the connecting ring portion. The outer wall of the outer ring portion protrudes from the outer wall of the first end of the piston rod. An avoidance groove is formed between the outer ring portion and the inner ring portion. The outer ring portion can shrink or expand along its radial direction.

9. The mini electric high-pressure air pump according to claim 7, characterized in that: The movement further includes a control circuit board and a power supply module. The control circuit board is connected to the mounting seat, and the control circuit board is electrically connected to the power supply module and the driving assembly respectively.

10. The mini electric high-pressure air pump according to claim 1, characterized in that: The mini electric high-pressure air pump also includes a shell and a cover. The shell includes a first side wall and four second side walls. The four second side walls are arranged end to end on the first side wall. An accommodating cavity is formed between the first side wall and the four second side walls. The movement is arranged in the accommodating cavity. The accommodating cavity has an opening facing away from the first side wall, and the cover is detachably arranged in the opening.

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