Surface grinding and dedusting machine based on 3D printed parts
By designing a surface polishing and dust removal machine for 3D printed parts, the problem of collecting debris and dust during the polishing process is solved by utilizing a dust removal and cleaning mechanism. This achieves efficient debris and dust handling, reduces the intensity of manual cleaning, and improves the hygiene of the working environment.
Patent Information
- Application Number
- CN202511075888.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-01
- Publication Date
- 2025-11-07
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Existing polishing equipment cannot effectively collect and process debris and dust when handling 3D printed parts, resulting in poor hygiene around the equipment and increasing the intensity of manual cleaning.
A surface polishing and dust removal machine based on 3D printed parts was designed, which includes a dust removal mechanism and a cleaning mechanism. It uses components such as a first sieve plate, a second sieve plate, a collection box, a dust suction fan, a filter element and a collection frame to collect and clean debris and dust.
It effectively collects and handles debris and dust during the polishing process, avoids splashing, reduces the intensity of manual cleaning, and improves the hygiene of the working environment.
Smart Images
Figure CN120901808A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of workpiece polishing equipment, in particular to a surface polishing and dust removing machine based on 3D printed parts. BACKGROUND
[0002] Polishing is a kind of surface modification technology, which generally refers to a processing method for changing the physical properties of a material surface by friction with the help of rough objects (sandpaper containing high-hardness particles, etc.), and the main purpose is to obtain a specific surface roughness.
[0003] For 3D printed models, they are widely used in the current market application, but after 3D printing, a large number of support grids will be generated on the surface, which need to be polished before they can be used as finished products.
[0004] A large amount of debris and dust is often generated during the polishing operation, but the polishing equipment in the prior art can usually only perform the polishing operation, and it is not convenient to collect the generated debris and dust. Since the debris and dust generated during the polishing operation cannot be effectively treated, the debris and dust will fly everywhere, resulting in a poor sanitary environment around the equipment. After the polishing operation is completed, the operator needs to clean the polishing equipment and the surrounding debris and dust, which results in a high work intensity of the dust removal operation during the polishing process.
[0005] To solve the above problems, the present application provides a surface polishing and dust removing machine based on 3D printed parts. SUMMARY
[0006] To solve the above problems, the present application provides a surface polishing and dust removing machine based on 3D printed parts.
[0007] To solve the above problems, the present application provides a surface polishing and dust removing machine based on 3D printed parts.
[0008] Preferably, the dust removing mechanism comprises a first sieve plate and a second sieve plate, the first sieve plate is fixedly arranged on one side of the equipment box, the second sieve plate is fixedly arranged on the upper end face of the machine box, the first sieve plate and the second sieve plate are in communication with the inner cavity of the machine box, the top wall of the machine box is slidably provided with a collection box, and the collection box is located below the first sieve plate and the second sieve plate.
[0009] Preferably, the inner side wall of the machine box is fixedly provided with two sliding rails, and the collection box is slidably arranged between the two sliding rails.
[0010] Preferably, the bottom wall of the collecting box is fixedly provided with a filter plate, the inner part of the machine box is fixedly provided with a dust collection fan and a flow guide cover, the flow guide cover is located below the filter plate, the bottom opening of the flow guide cover is fixedly provided with a filter core, and the suction port of the dust collection fan is located below the filter core.
[0011] Preferably, the bottom wall of the machine box is fixedly provided with a plurality of collecting frames and a plurality of guide hoppers, and the guide hoppers are located between the collecting frames and the filter core.
[0012] Preferably, the bottom wall of the machine box is provided with a plurality of exhaust grooves, and the exhaust grooves are located below the dust collection fan.
[0013] Preferably, the cleaning mechanism comprises an L-shaped fixed plate, an L-shaped adhesive tape is fixedly arranged on the L-shaped fixed plate, one end of the L-shaped adhesive tape is in movable contact with one side of a first sieve plate, the other end of the L-shaped adhesive tape is in movable contact with the upper surface of a second sieve plate, a lead screw is rotatably installed in the inner part of the equipment box, a threaded sleeve is threadedly rotatably installed at one end of the lead screw, a connecting rod is fixedly arranged on the outer wall of the threaded sleeve, a connecting plate is fixedly arranged at one end of the connecting rod, and one end of the connecting plate is fixedly connected with one end of the L-shaped fixed plate; a moving groove is arranged on one side of the equipment box, the connecting plate is in movable contact with the groove wall of the moving groove, a drive motor is fixedly arranged at one end of the equipment box, and the piston end of the drive motor is fixedly connected with the other end of the lead screw.
[0014] Preferably, a guide rod is fixedly installed on the top wall of the equipment box, a sliding sleeve is slidably arranged at one end of the guide rod, and the other end of the connecting plate is fixedly connected with the outer wall of the sliding sleeve.
[0015] Preferably, a collecting box is detachably installed on the other side of the machine box, a first L-shaped groove is arranged on the second side plate, a second L-shaped groove is arranged on one side of the collecting box, the L-shaped fixed plate and the L-shaped adhesive tape horizontally correspond to the first L-shaped groove and the second L-shaped groove, an inclined surface is arranged on the bottom wall of the second L-shaped groove, and a sliding cover plate is slidably arranged on the upper end face of the collecting box.
[0016] Preferably, two limiting clamping blocks are fixedly arranged on the other side of the machine box, the collecting box is detachably installed on the two limiting clamping blocks, a rubber pad is fixedly arranged on the inner wall of the limiting clamping block, and the bottom of the collecting box is in movable contact with one side of the rubber pad.
[0017] Compared with the prior art, the present application has the following beneficial effects:
[0018] 1. In the application, by setting dust removal mechanism on the case, the dust and debris generated during the polishing process above the case can be collected by the cooperation of the first sieve plate, the second sieve plate, the collection box, the dust collection fan, the filter element, the flow guide cover and the collection frame, and then collected into the collection box and the collection frame, so as to facilitate subsequent centralized processing, avoid the scattering of dust and debris, improve the convenience of cleaning operation around the case, and reduce the operation intensity of manual dust removal.
[0019] 2. In the application, by setting the cleaning mechanism on the case, the cooperation of the driving motor, the screw rod and the L-shaped fixed plate, the L-shaped rubber strip is driven to move horizontally, the L-shaped rubber strip scrapes off the dust and debris attached to one side of the first sieve plate and the dust and debris attached to the upper surface of the second sieve plate, and the scraped dust and debris falls into the collection box through the first L-shaped groove and the second L-shaped groove, so as to facilitate subsequent centralized processing, thereby improving the processing effect of dust and debris during polishing operation and reducing the operation intensity of manual cleaning. BRIEF DESCRIPTION OF DRAWINGS
[0020] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor.
[0021] Figure 1 It is a whole structure schematic view of the surface polishing and dust removal machine based on 3D printed parts of the application.
[0022] Figure 2 It is another whole structure schematic view of the surface polishing and dust removal machine based on 3D printed parts of the application.
[0023] Figure 3 It is an internal structure schematic view of the case of the application.
[0024] Figure 4 It is a structure schematic view of the equipment box, the dust removal mechanism and the cleaning mechanism of the application.
[0025] Figure 5 It is a structure schematic view of the cleaning mechanism and the second side plate of the application.
[0026] Figure 6 It is an enlarged schematic view of A part in the application. Figure 5
[0027] Figure 7 It is a structure schematic view of the separation of the sliding cover plate and the collection box and the separation of the collection box and the limiting clamping block of the application.
[0028] Figure 8 This is a cross-sectional structural diagram of the collection box of the present invention.
[0029] In the diagram: 1. Chassis; 11. Side panel 1; 12. Side panel 2; 13. Equipment box; 14. Box door; 15. Assembly rack; 16. Assembly hole; 2. Dust removal mechanism; 21. Screen plate 1; 22. Screen plate 2; 23. Collection box; 231. Sliding rail; 24. Filter plate; 25. Dust extraction fan; 27. Filter element; 28. Air guide hood; 29. Guide hopper; 3. Collection frame; 31. Exhaust duct; 4. Cleaning mechanism; 41. L-shaped fixing plate; 42. L-shaped rubber strip; 43. Lead screw; 44. Threaded sleeve; 45. Connecting rod; 46. Connecting plate; 47. Drive motor; 48. Guide rod; 49. Sliding sleeve; 5. Moving groove; 51. No. 1 L-shaped groove; 52. Collection box; 53. Limiting block; 531. Rubber pad; 54. No. 2 L-shaped groove; 55. Inclined surface; 56. Sliding cover plate. Detailed Implementation
[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0031] Example: Figures 1-8 As shown, this invention provides a surface polishing and dust removal machine based on 3D printed parts, including a chassis 1. A first side plate 11, a second side plate 12, and an equipment box 13 are fixedly mounted on the upper surface of the chassis 1. Two doors 14 are hinged to one side of the chassis 1. Two assembly frames 15 are fixedly arranged between the first side plate 11 and the second side plate 12. The assembly frames 15 have several assembly holes 16. By setting the assembly frames 15 and the assembly holes 16, polishing equipment can be assembled onto the assembly frames 15. A dust removal mechanism 2 is provided on the chassis 1 and the equipment box 13. A cleaning mechanism 4 is also provided. By setting up the dust removal mechanism 2 and the cleaning mechanism 4, when the grinding equipment performs grinding operations on the workpiece, the dust removal mechanism 2 can remove the dust and debris generated during the grinding process and collect the dust and debris. The cleaning mechanism 4 can clean up the small amount of residual dust and debris and collect the small amount of residual dust and debris, so as to prevent the dust and debris from staying on the machine box 1 and prevent the dust and debris from flying around during the grinding operation. This improves the convenience of dust and debris handling operations and reduces the workload of manual dust removal.
[0032] The dust removal mechanism 2 comprises a first sieve plate 21 and a second sieve plate 22, the first sieve plate 21 is fixedly arranged on one side of the equipment box 13, and the second sieve plate 22 is fixedly arranged on the upper end face of the machine box 1; the first sieve plate 21 and the second sieve plate 22 are communicated with the inner cavity of the machine box 1; the top wall of the machine box 1 is slidably provided with a collection box 23, and the collection box 23 is located below the first sieve plate 21 and the second sieve plate 22; by arranging the first sieve plate 21, the second sieve plate 22 and the collection box 23, most of the debris and dust in the polishing operation can fall into the collection box 23 through the first sieve plate 21 and the second sieve plate 22 and be collected by the collection box 23, so as to facilitate centralized treatment.
[0033] The inner side wall of the machine box 1 is fixedly provided with two sliding rails 231, and the collection box 23 is slidably arranged between the two sliding rails 231; by arranging the sliding rails 231, when the collection box 23 is horizontally pulled away from the machine box 1, the collection box 23 can be separated from the machine box 1, so as to facilitate pouring out the debris and dust collected in the collection box 23 and facilitating assembling the collection box 23 in the inner cavity of the machine box 1.
[0034] The bottom wall of the collection box 23 is fixedly provided with a filter plate 24; the inner side wall of the machine box 1 is fixedly provided with a dust collection fan 25 and a flow guide cover 28, and the flow guide cover 28 is located below the filter plate 24; a filter core 27 is fixedly arranged at the bottom opening of the flow guide cover 28, and the filter core 27 is assembled at the opening of the bottom end of the flow guide cover 28 by screws and can be individually disassembled, so as to facilitate replacement of the filter core 27 after saturation; the suction port of the dust collection fan 25 is located below the filter core 27; by arranging the dust collection fan 25, the filter core 27, the flow guide cover 28 and the filter plate 24, when the dust collection fan 25 operates, the airflow generated by the suction of the dust collection fan 25 can suck the debris and dust passing through the first sieve plate 21 and the second sieve plate 22 through the filter core 27, the flow guide cover 28 and the filter plate 24; the debris and dust larger than the filter holes of the filter plate 24 are retained in the collection box 23, and the debris and dust smaller than the filter holes of the filter plate 24 are discharged downward through the flow guide cover 28 and are adsorbed on the filter core 27.
[0035] The bottom wall of the machine box 1 is fixedly provided with a plurality of collection frames 3 and a plurality of guide hoppers 29; the collection frames 3 are fixedly arranged on the bottom wall of the machine box 1 by bolts; the guide hoppers 29 are located between the collection frames 3 and the filter core 27; by arranging the guide hoppers 29 and the collection frames 3, the excess debris and dust on the filter core 27 can slide into the collection frames 3 through the guide hoppers 29; after the collection frames 3 are removed, the debris and dust in the collection frames 3 can be poured out, so as to facilitate subsequent centralized treatment.
[0036] The bottom wall of the machine box 1 is provided with a plurality of exhaust grooves 31, and the exhaust grooves 31 are located below the dust collection fan 25; by arranging the exhaust grooves 31, the airflow can be discharged when the dust collection fan 25 operates, so as to ensure the normal operation of the dust collection fan 25.
[0037] The cleaning mechanism 4 comprises an L-shaped fixed plate 41, an L-shaped adhesive tape 42 is fixedly arranged on the L-shaped fixed plate 41, one end of the L-shaped adhesive tape 42 is in movable contact with one side of the first sieve plate 21, the other end of the L-shaped adhesive tape 42 is in movable contact with the upper surface of the second sieve plate 22, by arranging the L-shaped fixed plate 41 and the L-shaped adhesive tape 42, when the L-shaped fixed plate 41 moves horizontally on the upper end surface of the cabinet 1, the L-shaped adhesive tape 42 moves horizontally, the L-shaped adhesive tape 42 can scrape off a small amount of debris and dust remaining on the first sieve plate 21 and the second sieve plate 22, a lead screw 43 is rotatably arranged in the interior of the equipment box 13, a threaded sleeve 44 is threadedly rotatably arranged at one end of the lead screw 43, a connecting rod 45 is fixedly arranged on the outer wall of the threaded sleeve 44, a connecting plate 46 is fixedly arranged at one end of the connecting rod 45, one end of the connecting plate 46 is fixedly connected with one end of the L-shaped fixed plate 41, a moving groove 5 is arranged on one side of the equipment box 13, the connecting plate 46 is in movable contact with the groove wall of the moving groove 5, by driving the lead screw 43 to rotate, the lead screw 43 can drive the threaded sleeve 44 to move horizontally, the threaded sleeve 44 can move horizontally in the moving groove 5 through the connecting rod 45 and the connecting plate 46, the connecting plate 46 can make the L-shaped fixed plate 41 and the L-shaped adhesive tape 42 move horizontally synchronously, a driving motor 47 is fixedly arranged at one end of the equipment box 13, the piston end of the driving motor 47 is fixedly connected with the other end of the lead screw 43, by starting the driving motor 47, the driving motor 47 can make the lead screw 43 rotate.
[0038] A guide rod 48 is fixedly arranged on the top wall of the equipment box 13, a sliding sleeve 49 is slidably arranged at one end of the guide rod 48, the other end of the connecting plate 46 is fixedly connected with the outer wall of the sliding sleeve 49, by arranging the guide rod 48 and the sliding sleeve 49, the sliding sleeve 49 can slide horizontally on the guide rod 48, the sliding sleeve 49 can guide the connecting plate 46 and the threaded sleeve 44 in the horizontal direction, so that the connecting plate 46 and the threaded sleeve 44 keep moving in the horizontal direction.
[0039] A collecting box 52 is detachably arranged on the other side of the cabinet 1, a first L-shaped groove 51 is arranged on the second side plate 12, a second L-shaped groove 54 is arranged on one side of the collecting box 52, the L-shaped fixed plate 41 and the L-shaped adhesive tape 42 horizontally correspond to the first L-shaped groove 51 and the second L-shaped groove 54, by arranging the first L-shaped groove 51 and the second L-shaped groove 54, when the L-shaped fixed plate 41 and the L-shaped adhesive tape 42 move horizontally to one side of the second side plate 12, the cleaned debris and dust can enter the collecting box 52 through the first L-shaped groove 51 and the second L-shaped groove 54, the debris and dust are collected in the collecting box 52, so as to be conveniently treated in batches, an inclined surface 55 is arranged on the bottom wall of the second L-shaped groove 54, by arranging the inclined surface 55, the debris and dust can slide into the collecting box 52, a sliding cover plate 56 is slidably arranged on the upper end surface of the collecting box 52, by arranging the sliding cover plate 56, when the sliding cover plate 56 is slid open, the debris and dust in the collecting box 52 can be poured out, so as to be conveniently treated in batches.
[0040] The other side of the case 1 is fixedly provided with two limiting clamping blocks 53, and the collecting box 52 is detachably installed on the two limiting clamping blocks 53. The inner wall of the limiting clamping block 53 is fixedly provided with a rubber pad 531, and the bottom of the collecting box 52 is movably in contact with one side of the rubber pad 531. By arranging the limiting clamping block 53 and the rubber pad 531, the bottom of the collecting box 52 can be clamped into the limiting clamping block 53 by pressing the collecting box 52 downward, and the rubber pad 531 can improve the stability between the collecting box 52 and the limiting clamping block 53, so that the installation of the collecting box 52 is facilitated. When the collecting box 52 is pulled upward, the collecting box 52 is separated from the limiting clamping block 53, so that the collecting box 52 can be easily removed, and the collected debris and dust in the collecting box 52 can be easily poured out.
[0041] Working principle: when the polishing equipment is assembled on the assembling frame 15, as the polishing equipment performs polishing work on the workpiece, the debris and dust generated in the polishing process fall on the second sieve plate 22 and fall into the collecting box 23 through the second sieve plate 22, and at the same time, most of the debris and dust fall into the collecting box 23 through the first sieve plate 21, and are collected by the collecting box 23;
[0042] At the same time, the operator starts the dust collection fan 25, and the generated air flow is sucked through the filter element 27, the flow guide cover 28 and the filter plate 24 to suck the debris and dust passing through the first sieve plate 21 and the second sieve plate 22, wherein the debris and dust larger than the filter hole of the filter plate 24 are retained in the collecting box 23, and the debris and dust smaller than the filter hole of the filter plate 24 are discharged downward through the flow guide cover 28, are adsorbed on the filter element 27, and the excess debris and dust attached to the filter element 27 slide into the collecting frame 3 through the guide hopper 29. The debris and dust in the polishing process are collected by the collecting box 23 and the collecting frame 3, so as to facilitate subsequent centralized treatment and avoid the debris and dust flying everywhere;
[0043] When the polishing equipment stops working, the operator starts the driving motor 47, the driving shaft of the driving motor 47 drives the lead screw 43 to rotate, the lead screw 43 drives the threaded sleeve 44 to move horizontally, the threaded sleeve 44 moves horizontally in the moving groove 5 through the connecting rod 45 and the connecting plate 46, the connecting plate 46 synchronously drives the L-shaped fixed plate 41 and the L-shaped rubber strip 42 to move horizontally, and the L-shaped rubber strip 42 scrapes off the debris and dust attached to one side of the first sieve plate 21 and the debris and dust attached to the upper surface of the second sieve plate 22 in the process of horizontal movement. When the L-shaped fixed plate 41 and the L-shaped rubber strip 42 reach the position of the first L-shaped groove 51, the cleaned debris and dust slide into the collecting box 52 through the first L-shaped groove 51 and the second L-shaped groove 54, and a small amount of debris and dust remaining on the first sieve plate 21 and the second sieve plate 22 are collected by the collecting box 52, so as to facilitate subsequent centralized treatment.
[0044] Obviously, many modifications and variations of the present application are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims and their equivalents, the application can be practiced otherwise than as specifically described.
Claims
1. A dust removal machine based on surface polishing of 3D printed parts, comprising a cabinet (1), characterized in that: The upper end face of the case (1) is respectively provided with a first side plate (11), a second side plate (12) and a device box (13), one side of the case (1) is hingedly installed with two box doors (14), the first side plate (11) and the second side plate (12) are fixedly provided with a plurality of assembly frames (15), the assembly frames (15) are provided with a plurality of assembly holes (16), the case (1) and the device box (13) are provided with a dust removal mechanism (2), and the case (1) and the device box (13) are further provided with a cleaning mechanism (4).
2. The surface polishing and dust removing machine based on a 3D printed piece according to claim 1, characterized in that, The dust removal mechanism (2) comprises a first sieve plate (21) and a second sieve plate (22), the first sieve plate (21) is fixedly arranged on one side of the device box (13), the second sieve plate (22) is fixedly arranged on the upper end face of the case (1), the first sieve plate (21) and the second sieve plate (22) are communicated with the inner cavity of the case (1), and the top wall of the case (1) is slidably provided with a collecting box (23), the collecting box (23) is located below the first sieve plate (21) and the second sieve plate (22).
3. The surface polishing and dust removing machine based on a 3D printed piece according to claim 2, characterized in that, The inner side wall of the case (1) is fixedly provided with two sliding rails (231), and the collecting box (23) is slidably arranged between the two sliding rails (231).
4. The surface polishing and dust removing machine based on 3D printed parts according to claim 2, wherein, The bottom wall of the collecting box (23) is fixedly provided with a filter plate (24), the inner part of the case (1) is respectively fixedly provided with a dust suction fan (25) and a flow guide cover (28), the flow guide cover (28) is located below the filter plate (24), the bottom opening of the flow guide cover (28) is fixedly provided with a filter core (27), and the suction port of the dust suction fan (25) is located below the filter core (27).
5. The surface polishing and dust removing machine based on 3D printed parts according to claim 4, characterized in that, The bottom wall of the case (1) is fixedly provided with a plurality of collecting frames (3) and a plurality of guide hoppers (29), and the guide hoppers (29) are located between the collecting frames (3) and the filter core (27).
6. The surface polishing and dust removing machine based on 3D printed parts according to claim 4, wherein, The bottom wall of the case (1) is provided with a plurality of exhaust grooves (31), and the exhaust grooves (31) are located below the dust suction fan (25).
7. The 3D-printed object-based surface finishing dust removal machine of claim 2, wherein, The cleaning mechanism (4) comprises an L-shaped fixed plate (41), the L-shaped fixed plate (41) is fixedly provided with an L-shaped adhesive tape (42), one end of the L-shaped adhesive tape (42) is in movable contact with one side of the first sieve plate (21), the other end of the L-shaped adhesive tape (42) is in movable contact with the upper surface of the second sieve plate (22), a lead screw (43) is rotatably installed in the device box (13), one end of the lead screw (43) is threadedly rotatably installed with a threaded sleeve (44), the outer wall of the threaded sleeve (44) is fixedly provided with a connecting rod (45), one end of the connecting rod (45) is fixedly provided with a connecting plate (46), one end of the connecting plate (46) is fixedly connected with one end of the L-shaped fixed plate (41), one side of the device box (13) is provided with a moving groove (5), the connecting plate (46) is in movable contact with the groove wall of the moving groove (5), one end of the device box (13) is fixedly provided with a driving motor (47), and the piston end of the driving motor (47) is fixedly connected with the other end of the lead screw (43).
8. The surface polishing and dust removing machine based on 3D printed parts according to claim 7, characterized in that, The top wall of the equipment box (13) is fixedly provided with a guide rod (48), one end of the guide rod (48) is slidably provided with a sliding sleeve (49), and the other end of the connecting plate (46) is fixedly connected with the outer wall of the sliding sleeve (49). 9.The surface polishing and dust removing machine based on 3D printing according to claim 7, wherein, The other side of the case (1) is detachably provided with a collecting box (52), the second side plate (12) is provided with a first L-shaped groove (51), one side of the collecting box (52) is provided with a second L-shaped groove (54), the L-shaped fixed plate (41) and the L-shaped adhesive tape (42) horizontally correspond to the first L-shaped groove (51) and the second L-shaped groove (54), and the bottom wall of the second L-shaped groove (54) is provided with an inclined surface (55). The upper end surface of the collecting box (52) is slidably provided with a sliding cover plate (56). 10.The 3D printing-based surface polishing and dust removing machine according to claim 9, wherein, The other side of the case (1) is fixedly provided with two limiting clamping blocks (53), the collecting box (52) is detachably mounted on the two limiting clamping blocks (53), the inner wall of the limiting clamping block (53) is fixedly provided with a rubber pad (531), and the bottom of the collecting box (52) and one side of the rubber pad (531) are in movable contact.