Water tank assembly structure of a steam cleaner
Patent Information
- Application Number
- CN202522456972.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-19
- Publication Date
- 2026-10-30
- Estimated Expiration
- 2035-11-19
AI Technical Summary
[0002]传统的蒸汽清洗机,其水箱安装在外壳的安装槽上,外壳上设置有卡扣,水箱上设置有扣位,卡扣与扣位相互扣合,以使水箱锁定在安装槽上,卡扣上一体设置有按键,水箱拆卸时,需要按住按键,然后将水箱向安装槽外侧推动,以使卡扣脱离扣位,进而解锁水箱,再将水箱继续向安装槽外侧推动,以使水箱脱离安装槽,进而完成整个拆卸过程;上述拆卸过程由于需要按住按键,导致操作不方便
[0015]This utility model of a steam cleaner features a housing cavity inside the outer shell, a positioning seat on the outside of the housing cavity, a positioning element that is elastically movable on the positioning seat, and a positioning recess and an action surface on the water tank. When the water tank is inserted into the housing cavity, the water tank pushes the positioning element elastically out of the housing cavity through the action surface. After the action surface passes the positioning element, the positioning element resets under the action of elasticity and at least partially extends into the housing cavity, with the end of the positioning element engaging in the positioning recess, thus locking the water tank inside the housing cavity. When disassembling the water tank, this structure only requires force to pull the water tank out of the housing cavity, and the end of the positioning element will disengage from the positioning recess, thereby unlocking the water tank. Then, continue to pull the water tank out to disengage it from the housing cavity, thus completing the entire disassembly process without pressing any buttons, making the operation more convenient and improving the efficiency of water tank assembly and disassembly.
Smart Images

Figure CN224913182U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of steam cleaner technology, and in particular to a water tank assembly structure for a steam cleaner. Background Technology
[0002] Traditional steam cleaners have a water tank installed in a mounting slot on the outer casing. The outer casing has clips, and the water tank has a locking mechanism. The clips and locking mechanisms interlock to lock the water tank in the mounting slot. A button is integrated into the clip. To remove the water tank, you need to press the button and then push the water tank outward from the mounting slot to disengage the clips and unlock the water tank. Then, you need to push the water tank outward from the mounting slot again to remove it from the mounting slot, thus completing the entire removal process. This removal process is inconvenient because it requires pressing the button.
[0003] Therefore, further improvements are necessary. Utility Model Content
[0004] The purpose of this utility model is to provide a water tank assembly structure for a steam cleaner that is simple in structure, easy to operate, efficient in disassembly and assembly, provides a good user experience, and is highly practical, so as to overcome the shortcomings of the prior art.
[0005] A water tank assembly structure for a steam cleaner designed for this purpose includes an outer shell and a water tank. The structure is characterized by: a receiving cavity provided inside the outer shell, the water tank inserted into the receiving cavity, a positioning seat provided outside the receiving cavity, a positioning element elastically movably mounted on the positioning seat, the positioning element extending at least partially into the receiving cavity under elastic force, and a positioning recess and an action surface provided on the water tank. When the water tank is inserted into the receiving cavity, the water tank pushes the positioning element elastically out of the receiving cavity through the action surface. After the action surface passes the positioning element, the positioning element resets under elastic force and extends at least partially into the receiving cavity, with the end of the positioning element engaging the positioning recess to lock the water tank within the receiving cavity.
[0006] The water tank is provided with a guide groove, the first end of which extends to the first end of the water tank. The working surface is located between the end of the guide groove and the positioning recess. When the water tank is inserted into the receiving cavity, the end of the positioning member slides relative to the guide groove. When the end of the positioning member slides to the end of the guide groove, the working surface pushes the positioning member to elastically move out of the receiving cavity.
[0007] A first elastic element is sleeved on the positioning member. The first elastic element is disposed between the positioning member and the positioning seat. Under the elastic force of the first elastic element, the positioning member extends at least partially into the accommodating cavity. When the water tank pushes the positioning member to move elastically out of the accommodating cavity through the action surface, the first elastic element is compressed and stores energy. After the action surface passes the positioning member, the positioning member resets under the elastic force of the first elastic element.
[0008] The positioning seat has a movable hole, and the positioning member is movably mounted on the movable hole. The positioning member has a limiting part. One end of the first elastic member abuts against the limiting part, and the other end abuts against the top wall of the movable hole. The movable hole is connected to the receiving cavity. Under the elastic force of the first elastic member, the positioning member extends at least partially out of the movable hole. When the water tank pushes the positioning member elastically out of the receiving cavity through the action surface, the positioning member retracts into the movable hole. When the positioning member resets under the elastic force of the first elastic member, it abuts against the bottom wall of the movable hole through the limiting part.
[0009] A limiting plate is provided inside the accommodating cavity, and a rib is provided on the limiting plate. The rib is inclined upward along the direction in which the water tank is inserted into the accommodating cavity. When the water tank is inserted into the accommodating cavity, the rib abuts against the outer surface of the water tank so that a gap is formed between the water tank and the limiting plate.
[0010] The housing has a U-shaped positioning and mounting groove, and the positioning seat has a positioning edge on its outer periphery. The positioning edge is inserted into the positioning and mounting groove so that the positioning seat is positioned inside the housing.
[0011] The water tank has an outlet at its front end, and a one-way valve is installed on the outlet. The one-way valve includes a valve body, a second elastic element, and a valve ball. An outlet connector is installed inside the outer shell. The valve body is fixed inside the water tank. The second elastic element is located between the valve body and the valve ball. The valve ball closes the outlet under the elastic force of the second elastic element. When the water tank is inserted into the receiving cavity, the outlet connector pushes open the valve ball so that the outlet connects to the outlet connector, and the second elastic element is compressed and stores energy.
[0012] The water tank has an inlet at the front end, a sealing plug on the inlet, and a sealing part on the sealing plug for insertion into the inlet.
[0013] The outer shell has observation windows on both sides, which are connected to the accommodating cavity. The water tank is made of transparent material.
[0014] The end of the water tank is equipped with a cap, which closes the cavity when the water tank is inserted into it; the cap is equipped with an anti-slip pad, and the bottom of the outer shell is equipped with several anti-slip plates.
[0015] This utility model of a steam cleaner features a housing cavity inside the outer shell, a positioning seat on the outside of the housing cavity, a positioning element that is elastically movable on the positioning seat, and a positioning recess and an action surface on the water tank. When the water tank is inserted into the housing cavity, the water tank pushes the positioning element elastically out of the housing cavity through the action surface. After the action surface passes the positioning element, the positioning element resets under the action of elasticity and at least partially extends into the housing cavity, with the end of the positioning element engaging in the positioning recess, thus locking the water tank inside the housing cavity. When disassembling the water tank, this structure only requires force to pull the water tank out of the housing cavity, and the end of the positioning element will disengage from the positioning recess, thereby unlocking the water tank. Then, continue to pull the water tank out to disengage it from the housing cavity, thus completing the entire disassembly process without pressing any buttons, making the operation more convenient and improving the efficiency of water tank assembly and disassembly. Attached Figure Description
[0016] Figure 1 This is an exploded view of a portion of the structure of a steam cleaner according to one embodiment of the present invention.
[0017] Figure 2 This is a partial structural cross-sectional view of a steam cleaner in one embodiment of the present invention.
[0018] Figure 3 for Figure 2 A magnified structural diagram of point A in the middle.
[0019] Figure 4 This is an exploded structural diagram of the positioning seat, positioning element, and first elastic element in one embodiment of the present invention.
[0020] Figure 5 This is a partial cross-sectional view of the steam cleaner from another position in one embodiment of the present invention.
[0021] Figure 6 for Figure 5 A magnified structural diagram at point B in the middle.
[0022] Figure 7 for Figure 5 A magnified structural diagram at point C.
[0023] Figure 8 This is an exploded view of the one-way valve in one embodiment of the present invention.
[0024] Figure 9 This is a schematic diagram of the overall structure of the water tank in one embodiment of the present invention.
[0025] Figure 10 This is an exploded view of the water tank in one embodiment of the present invention.
[0026] Figure 11 This is a schematic diagram of the overall structure of the sealing plug in one embodiment of the present invention.
[0027] Figure 12 This is a partial structural diagram of a steam cleaner according to one embodiment of the present invention.
[0028] Figure 13 This is a partial structural diagram of the steam cleaner from another position in one embodiment of the present invention.
[0029] Figure 14 This is an exploded view of a portion of the structure of a steam cleaner in one embodiment of the present invention.
[0030] Figure 15 This is a schematic diagram of the overall structure of the steam cleaner in one embodiment of the present invention. Detailed Implementation
[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0032] See Figures 1-15 The water tank assembly structure of this steam cleaner includes an outer shell 1 and a water tank 2. An accommodating cavity 3 is provided inside the outer shell 1, and the water tank 2 is inserted into the accommodating cavity 3. A positioning seat 4 is provided on the outer top side of the accommodating cavity 3, and a positioning element 5 is elastically movably mounted on the positioning seat 4. Under the action of elastic force, the positioning element 5 at least partially extends into the accommodating cavity 3. A positioning recess 6 and an action surface 7 are provided on the outer surface of the water tank 2. When the water tank 2 is inserted (pushed) into the accommodating cavity 3, the water tank 2 pushes the positioning element 5 upwards and elastically moves it out of the accommodating cavity 3 through the action surface 7. After the action surface 7 passes the positioning element 5, the positioning element 5 resets and moves downwards under the action of elastic force, and at least partially... The water tank 2 is inserted into the receiving cavity 3, and the end of the positioning member 5 is engaged in the positioning recess 6, so that the water tank 2 is locked in the receiving cavity 3, thus completing the entire installation process; when disassembling the water tank 2, the water tank 2 is pulled out of the receiving cavity 3, and the water tank 2 pushes the positioning member 5 upward elastically out of the receiving cavity 3 through the action surface 7, so that the end of the positioning member 5 is disengaged from the positioning recess 6, thereby unlocking the water tank 2. After the action surface 7 passes the positioning member 5, the positioning member 5 is reset and moves downward under the action of elasticity, and at least partially extends into the receiving cavity 3. Then, the water tank 2 is pulled outward to disengage the water tank from the receiving cavity 3, thus completing the entire disassembly process.
[0033] The water tank 2 is provided with a guide groove 8, the first end of which extends to the first end of the water tank 2. The working surface 7 is located between the end of the guide groove 8 and the positioning recess 6. When the water tank 2 is inserted into the receiving cavity 3, the first end of the water tank 2 enters the receiving cavity 3 first. Then, the end of the positioning member 5 slides relative to the guide groove 8. When the end of the positioning member 5 slides to the end of the guide groove 8, the working surface 7 pushes the positioning member 5 upward and elastically moves it out of the receiving cavity 3. When the water tank 2 is disassembled, after the working surface 7 passes the positioning member 5, the end of the positioning member 5 slides relative to the guide groove 8 until it slides out of the guide groove 8. The guide groove 8 plays a positioning role in the installation of the water tank 2, ensuring that the end of the positioning member 5 can finally be inserted into the positioning recess 6.
[0034] A first elastic element 9, which is a spring, is fitted onto the positioning element 5. The first elastic element 9 is located between the positioning element 5 and the positioning seat 4. Under the elastic force of the first elastic element 9, the positioning element 5 extends at least partially into the accommodating cavity 3. When the water tank 2 pushes the positioning element 5 upward and elastically moves it out of the accommodating cavity 3 through the action surface 7, the first elastic element 9 is compressed and stores energy. After the action surface 7 passes the positioning element 5, the first elastic element 9 releases the stored energy. Under the elastic force of the first elastic element 9, the positioning element 5 moves downward and resets, and at least partially extends into the accommodating cavity 3.
[0035] The positioning seat 4 is provided with a movable hole 10. The positioning member 5 is movably mounted on the movable hole 10. The positioning member 5 is provided with a limiting part 11. The lower end of the first elastic member 9 abuts against the limiting part 11 and the upper end abuts against the top wall 12 of the movable hole 10. The movable hole 10 is connected to the accommodating cavity 3. Under the elastic force of the first elastic member 9, the positioning member 5 extends at least partially out of the movable hole 10, and then the positioning member 5 can extend at least partially into the accommodating cavity 3. When the water tank 2 pushes the positioning member 5 upward elastically out of the accommodating cavity 3 through the action surface 7, the positioning member 5 retracts into the movable hole 10. When the positioning member 5 resets and moves downward under the elastic force of the first elastic member 9, it abuts against the bottom wall 29 of the movable hole 10 through the limiting part 11 to limit the further downward movement of the positioning member 5, so that the positioning member 5 can be accurately reset.
[0036] A limiting plate 13 is provided at the bottom of the receiving cavity 3. The limiting plate 13 is provided with a protruding rib 14. The protruding rib 14 is inclined upward along the direction in which the water tank 2 is inserted into the receiving cavity 3, which plays a guiding role, so that the water tank 2 can be smoothly inserted into the receiving cavity 3. When the water tank 2 is inserted into the receiving cavity 3, the protruding rib 14 abuts against the outer surface of the water tank 2, so that a gap 30 is formed between the water tank 2 and the limiting plate 13. Since there is water in the water tank 2, the above structure can prevent the water tank 2 and the limiting plate 13 from being attracted to each other due to the surface tension of the water when the water tank 2 is inserted into the receiving cavity 3, thereby preventing the water tank 2 from being smoothly inserted into the receiving cavity 3. The positioning member 5 is located above the water tank 2, and the limiting plate 13 is located below the water tank 2. The positioning member 5 and the limiting plate 13 can position the water tank 2 vertically.
[0037] The outer casing 1 is provided with a U-shaped positioning mounting groove 15, and the outer periphery of the positioning seat 4 is provided with a positioning edge 16. The positioning edge 16 is inserted into the positioning mounting groove 15 so that the positioning seat 4 is positioned inside the outer casing 1.
[0038] The outer casing 1 is provided with a fixing hole 31, and the positioning seat 4 is provided with a fixing post hole 32. The fastener (screw) passes through the fixing hole 31 and is fastened to the fixing post hole 32 so that the positioning seat 4 is fixed inside the outer casing 1.
[0039] The positioning seat 4 includes a seat body 33 and a cover body 34 that covers the top of the seat body 33, and the movable hole 10 is provided inside the seat body 33.
[0040] The outer casing 1 includes a first casing 35 and a second casing 36 arranged on the left and right sides. The first casing 35 and the second casing 36 are connected by a snap fastener. Positioning mounting slots 15 are respectively arranged on the first casing 35 and the second casing 36. The positioning seat 4 is racetrack shaped, that is, the positioning edge 16 is racetrack shaped. Half of the positioning edge 16 is positioned and inserted into the positioning mounting slot 15 of the first casing 35, and the other half of the positioning edge 16 is positioned and inserted into the positioning mounting slot 15 of the second casing 36.
[0041] The water tank 2 has an outlet 17 at its head end, and a one-way valve is installed on the outlet 17. The one-way valve includes a valve body 18, a second elastic element 19, and a valve ball 20. An outlet connector 21 is installed inside the outer casing 1. The valve body 18 is fixed inside the water tank 2. The second elastic element 19 is located between the valve body 18 and the valve ball 20. The second elastic element 19 is a spring. The valve ball 20 closes the outlet 17 under the elastic force of the second elastic element 19. When the water tank 2 is not inserted into the receiving cavity 3, the valve ball 20 closes the outlet 17 to prevent water in the water tank 2 from leaking out of the water tank 2 through the outlet 17. When the water tank 2 is inserted into the receiving cavity 3, the outlet connector 21 pushes open the valve ball 20, and the outlet 17 opens so that the outlet 17 is connected to the outlet connector 21 (the outlet connector 21 is inserted into the outlet 17). The second elastic element 19 is compressed and stored.
[0042] The outer casing 1 is also equipped with a boiler 37 for generating steam. One end of the boiler 37 is equipped with a water inlet connector 38, and the water outlet connector 21 is connected to the water inlet connector 38 through a water pipe. A water pump is installed in the water tank 2. The water pump can draw water from the water tank 2 into the boiler 37 for heating, thereby generating steam. The above structure is the prior art and will not be described in detail here.
[0043] The water tank 2 has an inlet 22 at its front end, and a sealing plug 23 is provided on the inlet 22. The sealing plug 23 is provided with a sealing part 24 for being inserted into the inlet 22. The sealing part 24 is a sealing post and is used to seal the inlet 22. When water needs to be added to the water tank 2, the sealing plug 23 can be pulled out and water can be added to the water tank 2 through the inlet 22. When water needs to be drained from the water tank 2, the sealing plug 23 can also be pulled out and the water in the water tank 2 can be drained through the inlet 22.
[0044] One end of the sealing plug 23 is provided with an operating part 39 that bends outward from the water tank 2. The sealing plug 23 can be manually pulled out through the operating part 39, and the operating part 39 facilitates the removal of the sealing plug 23.
[0045] The outer shell 1 has observation windows 25 on both sides, which are connected to the accommodating cavity 3. The water tank 2 is made of transparent material. This structure allows the water level in the water tank 2 to be observed through the observation windows 25 so that water can be replenished in time when the water tank 2 is empty.
[0046] The end of the water tank 2 is provided with a cover 26. When the water tank 2 is inserted into the receiving cavity 3, the cover 26 closes the receiving cavity 3. The cover 26 is provided with an anti-slip pad 27, and the bottom of the outer shell 1 is provided with several anti-slip pieces 28. When the water tank 2 is inserted into or pulled out of the receiving cavity 3, it is necessary to grasp the cover 26 for operation. The anti-slip pad 27 can prevent the hand from slipping and not being able to grasp the cover 26 tightly during operation. When the bottom of the outer shell 1 is supported by a support, the anti-slip pieces 28 can prevent the steam cleaner from sliding.
[0047] The cover 26 is provided with a connecting rib 49, and the end of the water tank 2 is provided with a connecting groove 50. The connecting rib 49 and the connecting groove 50 are connected to each other so that the cover 26 is fixed to the end of the water tank 2.
[0048] An electrical cavity 40 is also provided inside the outer casing 1. The boiler 37 and the electrical control board 41 are provided inside the electrical cavity 40. The electrical control board 41 is electrically connected to the boiler 37. A wire passage 42 for passing power cords is provided on the outside of the outer casing 1. A wire passage component 43 is provided inside the outer casing 1. A wire passage hole 44 is provided on the wire passage component 43. A wire clamping hole 45 is provided on the outside of the boiler 37. A wire passage channel 46 is also provided inside the outer casing 1. The wire passage channel 46 is located between the electrical cavity 40 and the accommodating cavity 3. The branch wires of the power cord pass through the wire passage hole 44, the wire passage channel 46 and the wire clamping hole 45 in sequence and then connect to the electrical control board 41, which facilitates wiring.
[0049] The steam cleaner includes a connecting pipe 47 and a floor brush 48. The outer casing 1 is connected to the floor brush 48 through the connecting pipe 47. The floor brush 48 is provided with a steam outlet. The boiler 37, the connecting pipe 47 and the steam outlet are connected in sequence. The steam generated by the boiler 37 reaches the steam outlet through the connecting pipe 47 and is released through the steam outlet to sterilize the surface of the items. The above structure is the prior art and will not be described in detail here.
[0050] The above describes the preferred embodiments of this utility model, illustrating and describing its basic principles, main features, and advantages. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made without departing from the spirit and scope of this utility model, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.
Claims
1. A water tank assembly structure for a steam cleaner, comprising an outer shell (1) and a water tank (2), characterized in that: The outer shell (1) is provided with a receiving cavity (3), and the water tank (2) is inserted into the receiving cavity (3). A positioning seat (4) is provided on the outside of the receiving cavity (3). A positioning element (5) is elastically and movably provided on the positioning seat (4). The positioning element (5) extends into the receiving cavity (3) at least partially under the action of elastic force. The water tank (2) is provided with a positioning recess (6) and an action surface (7). When the water tank (2) is inserted into the receiving cavity (3), the water tank (2) pushes the positioning element (5) to elastically move out of the receiving cavity (3) through the action surface (7). After the action surface (7) passes the positioning element (5), the positioning element (5) resets under the action of elastic force and extends into the receiving cavity (3) at least partially. The end of the positioning element (5) is stuck into the positioning recess (6) so that the water tank (2) is locked in the receiving cavity (3).
2. The water tank assembly structure of the steam cleaner according to claim 1, characterized in that: A guide groove (8) is provided on the water tank (2). The first end of the guide groove (8) extends to the first end of the water tank (2). The working surface (7) is located between the end of the guide groove (8) and the positioning recess (6). When the water tank (2) is inserted into the accommodating cavity (3), the end of the positioning member (5) slides relative to the guide groove (8). When the end of the positioning member (5) slides to the end of the guide groove (8), the working surface (7) pushes the positioning member (5) to elastically move out of the accommodating cavity (3).
3. The water tank assembly structure of the steam cleaner according to claim 1, characterized in that: The positioning member (5) is fitted with a first elastic member (9), which is located between the positioning member (5) and the positioning seat (4). Under the elastic force of the first elastic member (9), the positioning member (5) extends into the accommodating cavity (3) at least partially. When the water tank (2) pushes the positioning member (5) to move out of the accommodating cavity (3) through the action surface (7), the first elastic member (9) is compressed and stored. After the action surface (7) passes the positioning member (5), the positioning member (5) resets under the elastic force of the first elastic member (9).
4. The water tank assembly structure of the steam cleaner according to claim 3, characterized in that: The positioning seat (4) is provided with a movable hole (10), and the positioning member (5) is movably disposed on the movable hole (10). The positioning member (5) is provided with a limiting part (11). One end of the first elastic member (9) abuts against the limiting part (11) and the other end abuts against the top wall (12) of the movable hole (10). The movable hole (10) is connected to the accommodating cavity (3). Under the elastic force of the first elastic member (9), the positioning member (5) extends at least partially out of the movable hole (10). When the water tank (2) pushes the positioning member (5) to move elastically out of the accommodating cavity (3) through the action surface (7), the positioning member (5) retracts into the movable hole (10). When the positioning member (5) resets under the elastic force of the first elastic member (9), it abuts against the bottom wall (29) of the movable hole (10) through the limiting part (11).
5. The water tank assembly structure of the steam cleaner according to claim 1, characterized in that: A limiting plate (13) is provided inside the accommodating cavity (3). A rib (14) is provided on the limiting plate (13). The rib (14) is inclined upward along the direction in which the water tank (2) is inserted into the accommodating cavity (3). When the water tank (2) is inserted into the accommodating cavity (3), the rib (14) abuts against the outer surface of the water tank (2) so that a gap (30) is formed between the water tank (2) and the limiting plate (13).
6. The water tank assembly structure of the steam cleaner according to claim 1, characterized in that: The outer shell (1) is provided with a U-shaped positioning mounting groove (15), and the outer periphery of the positioning seat (4) is provided with a positioning edge (16). The positioning edge (16) is inserted into the positioning mounting groove (15) so that the positioning seat (4) is positioned inside the outer shell (1).
7. The water tank assembly structure of the steam cleaner according to claim 1, characterized in that: The water tank (2) is provided with an outlet (17) at the front end. A one-way valve is provided on the outlet (17). The one-way valve includes a valve body (18), a second elastic element (19) and a valve ball (20). An outlet connector (21) is provided inside the outer shell (1). The valve body (18) is fixed inside the water tank (2). The second elastic element (19) is located between the valve body (18) and the valve ball (20). The valve ball (20) closes the outlet (17) under the elastic force of the second elastic element (19). When the water tank (2) is inserted into the receiving cavity (3), the outlet connector (21) pushes open the valve ball (20) so that the outlet (17) is connected to the outlet connector (21). The second elastic element (19) is compressed and stored.
8. The water tank assembly structure of the steam cleaner according to claim 1, characterized in that: The water tank (2) has an inlet (22) at its front end, and a sealing plug (23) is provided on the inlet (22). The sealing plug (23) has a sealing part (24) for inserting into the inlet (22).
9. The water tank assembly structure of the steam cleaner according to claim 1, characterized in that: The outer shell (1) has observation windows (25) on both sides, which are connected to the accommodating cavity (3). The water tank (2) is made of transparent material.
10. The water tank assembly structure of the steam cleaner according to claim 1, characterized in that: The end of the water tank (2) is provided with a cap (26). When the water tank (2) is inserted into the accommodating cavity (3), the cap (26) closes the accommodating cavity (3). The cap (26) is provided with an anti-slip pad (27), and the bottom of the outer shell (1) is provided with several anti-slip pieces (28).