Wall surface grinding equipment for building decoration

Abstract

The invention belongs to the field of buildings, and particularly relates to wall surface grinding equipment for building decoration. Wall surface grinding equipment for building decoration can improve the grinding efficiency and conveniently grind corners and comprises a connecting part used for being held by hand and connected with external equipment and a mounting part used for mounting a grinding mechanism, and the mounting part can adjust the position of the grinding mechanism; the wall body polishing part is used for polishing a wall body; and the corner polishing part is used for polishing corners of the wall body. Through the handheld connecting part and the wall body polishing part, the wall surface can be rapidly polished, and the working efficiency is improved; the corners of the wall body can be polished through the corner polishing part, so that the wall body can be comprehensively polished, and the attractiveness of the wall body is improved; and through the dust collection part, dust generated by wall polishing can be rapidly cleaned, and the health of workers can be better protected.

Description

Technical Field

[0001] The invention belongs to the field of construction, and in particular relates to a wall surface grinding device for building decoration. Background Art

[0002] With the vigorous development of the building decoration industry, people's requirements for wall decoration effects are increasing. The flatness and smoothness of the wall surface directly affect the adhesion effect of subsequent paint, wallpaper and other decorative materials as well as the overall aesthetics. Therefore, wall surface polishing has become a key link in building decoration construction.

[0003] Traditional wall surface grinding mainly relies on manual operation of handheld grinding tools, such as sandpaper and grinding wheels. Workers need to hold the tools for a long time and repeatedly grind the wall based on their experience and physical strength. This method has many disadvantages. On the one hand, manual grinding is extremely inefficient, especially when dealing with large-area walls, which consumes a lot of manpower and time costs, seriously slowing down the progress of the project; taking the wall grinding of an ordinary house as an example, if only one skilled worker is relied on, it may take several days to complete the initial grinding of all the walls, not including the subsequent fine grinding process.

[0004] On the other hand, when sanding the corners of the wall, it is difficult for the tool to reach into the edge of the corner for sanding due to the angle problem. Therefore, after sanding the wall, it will be found that there is an obvious deviation in the corner position, which affects the appearance.

[0005] Therefore, it is urgent to develop a wall surface grinding device for building decoration that can improve grinding efficiency and facilitate grinding corners. Summary of the invention

[0006] In order to overcome the above-mentioned shortcomings of the prior art, the present invention provides a wall surface grinding device for building decoration, which can improve the grinding efficiency and facilitate the grinding of corners.

[0007] The technical solution of the present invention is: a wall surface grinding device for building decoration, including a connecting part for holding and connecting with an external device, a mounting part for installing a grinding mechanism, the mounting part can adjust the position of the grinding mechanism, a wall grinding part for grinding the wall and a corner grinding part for grinding the corner of the wall; a grinding disc is arranged in the wall grinding part, and the corner grinding part includes a guide rod, a grinding block, a spring III and a clamping shaft, at least two guide rods are evenly spaced at the eccentric position of the grinding disc, and the guide rods are slidably connected with grinding blocks, the left side surface of the grinding block and the outer side surface of the grinding disc are on the same vertical plane, a spring III is connected between the grinding block and the grinding disc, and a clamping shaft is fixedly connected to the right side of the grinding disc.

[0008] Furthermore, the connecting part includes a connecting rod, a sliding rod, a clamping plate, a threaded sleeve, a connecting hose, a connecting plate and a connecting head. The lower part of the connecting rod is slidably connected to the sliding rod, the upper part of the sliding rod is provided with an external thread, the top of the sliding rod is provided with a circle of clamping plates that are indented inwardly, the external thread on the upper part of the sliding rod is threadedly connected to the threaded sleeve, the upper part of the threaded sleeve has a conical portion that is indented inwardly, the conical portion of the threaded sleeve is on the outside of the clamping plate, the top of the connecting rod is connected to a connecting hose, the top of the connecting hose is connected to a connecting head, and a connecting plate is fixedly connected between the connecting head and the outer side of the connecting rod.

[0009] Furthermore, the mounting portion includes a support plate, a rotating frame, a fastening bolt I, a mounting cover and a fastening bolt II. A support plate extending upward is symmetrically arranged on the outer side of the connecting head. A rotating frame is rotatably connected between the tops of the support plates. The rotating frame can be fixed to the support plate by fastening bolts I. A mounting cover that can rotate is arranged on the upper part of the rotating frame, and the mounting cover is fixed to the rotating frame by fastening bolts II.

[0010] Furthermore, the wall grinding part includes a grinding motor, a transmission box, a transmission shaft, a grinding disc, a clamping disc, a spring I, a clamping block and a spring II. The right side of the mounting cover is fixedly connected with the grinding motor, the output shaft of the grinding motor is connected with the transmission shaft through the transmission box, a grinding disc is coaxially arranged on the left side of the mounting cover, the transmission shaft passes through the grinding disc, a clamping disc is slidably connected to the transmission shaft by means of a key, a spring I is connected between the clamping disc and the mounting cover, the left and right parts of the clamping disc are slidably connected, a spring II is sleeved on the transmission shaft between the clamping disc and the transmission box, clamping blocks are evenly spaced at eccentric positions on the left side of the clamping disc, and the clamping blocks are clamped into the grinding disc.

[0011] Furthermore, it also includes a pushing part, which is symmetrically fixed on the front and rear sides of the right side of the installation cover. The pushing part includes a mounting block symmetrically arranged on the right side of the installation cover and a wedge block slidably installed on the mounting block.

[0012] Furthermore, it also includes a vibration part. The vibration part is arranged on the right side of the mounting cover. The vibration part includes a transmission pulley group, an eccentric wheel, a large transmission wheel and a small transmission wheel. The transmission pulley group is evenly spaced and rotated on the right side of the mounting cover. The transmission pulley group consists of a small pulley, a large pulley and a transmission belt. The transmission belt is wound between the small pulley and the large pulley. The eccentric wheel is arranged on the left side of the large pulley in the transmission pulley group, and the small transmission wheel is arranged on the left side of the small pulley. A large transmission wheel is arranged at the center of the right side of the clamping disk.

[0013] Furthermore, it also includes a dust suction part, which includes a dust suction pipe installed between the installation cover and the connecting head, and a dust inlet hole is opened on the grinding disc on the left side of the dust suction pipe.

[0014] Furthermore, the edge of the sanding block is wrapped with a protective layer.

[0015] The beneficial effects are as follows: the present invention can quickly polish the wall surface through the handheld connection part and the wall polishing part, thereby improving work efficiency; the corners of the wall can be polished through the corner polishing part, so that the wall can be fully polished, thereby improving the aesthetics of the wall; the dust generated by polishing the wall can be quickly cleaned through the dust suction part, thereby better protecting the health of the staff. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0017] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention.

[0018] Figure 2 It is a schematic diagram of the three-dimensional structure from another viewing angle of the present invention.

[0019] Figure 3 It is a schematic diagram of the three-dimensional structure of the connecting part of the present invention.

[0020] Figure 4 It is a schematic diagram of the three-dimensional structure of the mounting part of the present invention.

[0021] Figure 5 It is a three-dimensional structural schematic diagram of the installation cover inner component of the present invention.

[0022] Figure 6 It is a schematic diagram of the three-dimensional structure of the wall polishing part of the present invention.

[0023] Figure 7 It is a cross-sectional view of the clamping disk of the present invention.

[0024] Figure 8 For the present invention Figure 7 Magnified view of part B.

[0025] Fig. 9 For the present invention Figure 5 Enlarged view of part A.

[0026] Fig.10 It is a schematic diagram of the three-dimensional structure of the vibration part of the present invention.

[0027] Fig.11 It is a schematic diagram of the three-dimensional structure of the pushing part of the present invention.

[0028] Fig.12 It is a schematic diagram of the three-dimensional structure of the dust collection part of the present invention.

[0029] Figure numbers: 1_connecting part, 101_connecting rod, 102_sliding rod, 103_clamping plate, 104_threaded sleeve, 105_connecting hose, 106_connecting plate, 107_connecting head, 2_installation part, 201_support plate, 202_rotating frame, 203_fastening bolt I, 204_installation cover, 205_fastening bolt II, 3_wall polishing part, 301_polishing motor, 302_transmission box, 303_transmission shaft, 304_polishing Disk, 305_clamping disk, 306_spring I, 307_clamping block, 308_spring II, 4_corner grinding part, 401_guide rod, 402_grinding block, 403_spring III, 404_clamping shaft, 5_pushing part, 501_mounting block, 502_wedge block, 6_vibrating part, 601_transmission pulley group, 602_eccentric wheel, 603_large transmission wheel, 604_small transmission wheel, 7_dust suction part, 701_dust inlet hole, 702_dust suction pipe. DETAILED DESCRIPTION

[0030] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0031] Thus, a feature indicated in this specification will be used to illustrate one of the features of an embodiment of the present invention, rather than implying that each embodiment of the present invention must have the described feature. In addition, it should be noted that this specification describes many features. Although some features can be combined together to illustrate possible system designs, these features can also be used in other combinations that are not explicitly described. Thus, unless otherwise stated, the described combinations are not intended to be limiting.

[0032] In the description of the present application, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0033] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0034] Embodiment: A wall surface polishing device for building decoration, such as Figure 1-Figure 9As shown, it includes a connecting part 1 for holding and connecting to an external device, a mounting part 2 for mounting a grinding mechanism, the mounting part 2 can adjust the position of the grinding mechanism, a wall grinding part 3 for grinding a wall, and a corner grinding part 4 for grinding a wall corner.

[0035] like Figure 3 As shown, the connection part 1 includes a connecting rod 101, a sliding rod 102, a clamping piece 103, a threaded sleeve 104, a connecting hose 105, a connecting plate 106 and a connecting head 107. The lower part of the connecting rod 101 is slidably connected to the sliding rod 102. The upper part of the sliding rod 102 is provided with an external thread. The top of the sliding rod 102 is provided with a circle of clamping pieces 103 that are indented inwardly. The external thread on the upper part of the sliding rod 102 is connected to the threaded sleeve 104 through a thread. The upper part of the threaded sleeve 104 has a conical portion that is indented inwardly. The thread The tapered portion of the sleeve 104 is on the outside of the clamping piece 103. By screwing the threaded sleeve 104 downward, the clamping piece 103 can be pressed against the outer surface of the connecting rod 101, and the sliding rod 102 can be fixed on the connecting rod 101. A connecting hose 105 is connected to the top of the connecting rod 101, and a connecting head 107 is connected to the top of the connecting hose 105. A connecting plate 106 is fixedly connected to the connecting head 107 and the outer side of the connecting rod 101 by bolts. The connecting rod 101, the sliding rod 102 and the connecting head 107 are all hollow.

[0036] like Figure 4 As shown, the mounting portion 2 includes a support plate 201, a rotating frame 202, a fastening bolt I 203, a mounting cover 204 and a fastening bolt II 205. The outer side of the connecting head 107 is symmetrically provided with a support plate 201 extending upward, and a rotating frame 202 is rotatably connected between the tops of the support plates 201. The rotating frame 202 can be fixed to the support plate 201 by the fastening bolt I 203, so that the rotating frame 202 cannot rotate. A mounting cover 204 capable of self-rotation is provided on the upper part of the rotating frame 202. The mounting cover 204 is fixed to the rotating frame 202 by the fastening bolts II 205. The mounting cover 204 can be fixed to the rotating frame 202 by the fastening bolts II 205 so that it cannot rotate.

[0037] like Figure 6-Figure 8As shown, the wall grinding part 3 includes a grinding motor 301, a transmission box 302, a transmission shaft 303, a grinding disc 304, a clamping disc 305, a spring I 306, a clamping block 307 and a spring II 308. The right side of the mounting cover 204 is fixedly connected with the grinding motor 301 by bolts, and the output shaft of the grinding motor 301 is connected with the transmission shaft 303 through the transmission box 302. The transmission box 302 is driven by a gear or a pulley. The transmission shaft 303 is at the center of the right side of the mounting cover 204, and the left side of the mounting cover 204 is coaxially provided with a grinding disc 304. The transmission shaft 303 passes through the grinding disc 304. The transmission shaft 303 is connected by a key. A snap-in disk 305 is slidably connected thereto, a spring I 306 is connected between the snap-in disk 305 and the mounting cover 204, the left and right parts of the snap-in disk 305 are slidably connected, the sliding part of the snap-in disk 305 is on the left side of the spring I 306, a spring II 308 is sleeved on the transmission shaft 303 between the snap-in disk 305 and the transmission box 302, the right end of the spring II 308 is fixedly connected to the transmission box 302, the left end of the spring II 308 contacts the snap-in disk 305, and clamping blocks 307 are evenly spaced at eccentric positions on the left side of the snap-in disk 305, the clamping blocks 307 are clamped into the grinding disk 304, so that the grinding disk 304 can rotate together with the snap-in disk 305.

[0038] like Fig. 9 As shown, the corner grinding part 4 includes a guide rod 401, a grinding block 402, a spring III 403 and a clamping shaft 404. Four guide rods 401 are evenly spaced at the eccentric position of the grinding disc 304. The guide rods 401 are slidably connected with grinding blocks 402. The left side of the grinding block 402 and the outer side of the grinding disc 304 are on the same vertical plane. A spring III 403 is connected between the grinding block 402 and the grinding disc 304. The clamping shaft 404 is fixedly connected to the right side of the grinding disc 304 by bolts. The clamping shaft 404 is clamped on the inner side edge of the clamping disc 305 in the initial state. At this time, the spring III 403 is in a stretched state, and the edge of the grinding block 402 is wrapped with a protective layer to prevent the edge of the grinding block 402 from damaging the adjacent wall head.

[0039] When using the device to grind a wall, first loosen the threaded sleeve 104, pull the sliding rod 102 downward to the required length, then tighten the threaded sleeve 104, fix the sliding rod 102, then loosen the fastening bolts Ⅰ203 and the fastening bolts Ⅱ205, adjust the angle of the mounting cover 204 and its upper parts, then tighten the fastening bolts Ⅰ203 and the fastening bolts Ⅱ205, the angle of the mounting cover 204 and its upper parts is fixed, then control the grinding motor 301 to start working, drive the transmission shaft 303 to start rotating through the transmission box 302, thereby driving the left part of the clamping disk 305 to start rotating, thereby driving the grinding disc 304 to start rotating, then the person holds the sliding rod 102, aligns the grinding disc 304 with the grinding position of the wall, and starts grinding. When it is necessary to grind the corner, the grinding motor 301 is first controlled to stop working, and then the clamping plate 305 is pulled to the right. At this time, the spring I 306 and the spring II 308 are compressed, and the clamping block 307 is separated from the grinding disc 304. The clamping shaft 404 is no longer limited by the clamping disc 305, and the spring III 403 in the stretched state is reset, driving the grinding block 402 to move outward, and then the corner is grinded by the grinding block 402. After the corner is polished, the grinding block 402 is first pushed to move inward and reset, and the spring III 403 is stretched again. At this time, the clamping disc 305 is released, and under the action of the reset of the spring I 306 and the spring II 308, the clamping disc 305 moves to the left and resets, and the clamping shaft 404 is clamped again, and the clamping block 307 is re-stuck on the grinding disc 304.

[0040] like Fig.11 As shown, it also includes a pushing part 5. The right side of the mounting cover 204 is symmetrically fixed with the pushing part 5 by bolts. The pushing part 5 includes a mounting block 501 symmetrically arranged on the right side of the mounting cover 204, and a wedge block 502 slidably installed on the mounting block 501. The wedge surface of the wedge block 502 faces to the right, and the leftmost side of the inclined surface of the wedge block 502 is on the left side of the right part of the clamping plate 305.

[0041] When the clamping plate 305 is pushed to the right, the wedge block 502 can be squeezed inward, and the wedge block 502 pushes the clamping plate 305 to move to the right. When the non-inclined part on the right side of the wedge block 502 contacts the clamping plate 305, the clamping plate 305 is clamped to prevent the clamping plate 305 from moving to the left and resetting. In this way, the device can be used more conveniently.

[0042] like Fig.10As shown, it also includes a vibration part 6. The vibration part 6 is arranged on the right side of the mounting cover 204. The vibration part 6 includes a transmission pulley group 601, an eccentric wheel 602, a large transmission wheel 603 and a small transmission wheel 604. The transmission pulley group 601 is evenly spaced and rotated on the right side of the mounting cover 204. The transmission pulley group 601 is composed of a small pulley, a large pulley and a transmission belt. The transmission belt is wound between the small pulley and the large pulley. The eccentric wheel 602 is arranged on the left side of the large pulley in the transmission pulley group 601, and the small transmission wheel 604 is arranged on the left side of the small pulley. The large transmission wheel 603 is arranged at the center of the right side of the clamping disk 305, and the large transmission wheel 603 can drive the small transmission wheel 604 to rotate.

[0043] When grinding the corner of the wall, the clamping plate 305 moves to the right, causing the large transmission wheel 603 to move to the right. When the non-sloped part on the right side of the wedge block 502 contacts the clamping plate 305, the large transmission wheel 603 engages with the small transmission wheel 604. At this time, the grinding motor 301 is controlled to start working, and the large transmission wheel 603 is driven to rotate by the grinding motor 301, thereby driving the small transmission wheel 604 to rotate, thereby driving the eccentric wheel 602 to rotate through the transmission pulley group 601. The rotation of the eccentric wheel 602 generates vibration, causing the grinding block 402 to vibrate to grind the corner. After the grinding of the corner is completed, the grinding motor 301 is controlled to stop working. At this time, the clamping plate 305 is moved to the left and reset, and the large transmission wheel 603 is disengaged from the small transmission wheel 604.

[0044] like Fig.12 As shown, it also includes a dust suction part 7, which includes a dust suction pipe 702 installed between the installation cover 204 and the connecting head 107. A dust inlet hole 701 is opened on the grinding disc 304 on the left side of the dust suction pipe 702. Dust is sucked in through the dust inlet hole 701 and then discharged through the dust suction pipe 702, the connecting head 107, the connecting rod 101 and the sliding rod 102.

[0045] When grinding the wall, dust enters the dust suction pipe 702 through the dust inlet hole 701, and the vacuum cleaner is brought into contact with the bottom end of the sliding rod 102. The dust generated by grinding is sucked away through the dust suction pipe 702, the connecting head 107, the connecting rod 101 and the sliding rod 102.

[0046] The technical principles of the embodiments of the present invention are described above in conjunction with specific embodiments. These descriptions are only for explaining the principles of the embodiments of the present invention and cannot be interpreted in any way as limiting the protection scope of the embodiments of the present invention. Based on the explanations herein, those skilled in the art can think of other specific implementation methods of the embodiments of the present invention without creative work, and these methods will fall within the protection scope of the embodiments of the present invention.

Claims

1. A wall surface polishing device for building decoration, comprising a connecting portion (1) for holding and connecting to an external device, a mounting portion (2) for mounting a polishing mechanism, the mounting portion (2) being capable of adjusting the position of the polishing mechanism, a wall polishing portion (3) for polishing a wall, and a corner polishing portion (4) for polishing a wall corner; characterized in that: The wall grinding part (3) contains a grinding disc (304), and the corner grinding part (4) comprises a guide rod (401), a grinding block (402), a spring III (403) and a clamping shaft (404). At least two guide rods (401) are evenly spaced at an eccentric position of the grinding disc (304), and the guide rods (401) are slidably connected to the grinding blocks (402). The left side of the grinding block (402) and the outer side of the grinding disc (304) are on the same vertical plane. A spring III (403) is connected between the grinding block (402) and the grinding disc (304), and the clamping shaft (404) is fixedly connected to the right side of the grinding disc (304).

2. A wall surface grinding device for building decoration as claimed in claim 1, characterized in that: The connecting portion (1) comprises a connecting rod (101), a sliding rod (102), a clamping sheet (103), a threaded sleeve (104), a connecting hose (105), a connecting plate (106) and a connecting head (107). The lower portion of the connecting rod (101) is slidably connected to the sliding rod (102). The upper portion of the sliding rod (102) is provided with an external thread. The top of the sliding rod (102) is provided with a circle of clamping sheets (103) that are retracted inwards. The external thread on the upper portion of the sliding rod (102) is threadedly connected to the threaded sleeve (104). The upper portion of the threaded sleeve (104) is provided with a tapered portion that is retracted inwards. The tapered portion of the threaded sleeve (104) is located outside the clamping sheet (103). The top of the connecting rod (101) is connected to the connecting hose (105). The top of the connecting hose (105) is connected to the connecting head (107). The connecting plate (106) is fixedly connected between the connecting head (107) and the outer side of the connecting rod (101).

3. A wall surface grinding device for building decoration as claimed in claim 2, characterized in that: The mounting portion (2) comprises a support plate (201), a rotating frame (202), a fastening bolt I (203), a mounting cover (204) and a fastening bolt II (205); a support plate (201) extending upward is symmetrically arranged on the outer side of the connecting head (107); a rotating frame (202) is rotatably connected between the tops of the support plates (201); the rotating frame (202) can be fixed to the support plate (201) by means of the fastening bolt I (203); a mounting cover (204) capable of self-rotation is arranged on the upper part of the rotating frame (202); and the mounting cover (204) is fixed to the rotating frame (202) by means of the fastening bolt II (205).

4. A wall surface grinding device for building decoration as claimed in claim 3, characterized in that: The wall polishing part (3) comprises a polishing motor (301), a transmission box (302), a transmission shaft (303), a polishing disc (304), a clamping disc (305), a spring I (306), a clamping block (307) and a spring II (308). The right side of the mounting cover (204) is fixedly connected to the polishing motor (301), the output shaft of the polishing motor (301) is connected to the transmission shaft (303) through the transmission box (302), the left side of the mounting cover (204) is coaxially rotatably provided with a polishing disc (304), and the transmission shaft (303) passes through the mounting cover (204). A clamping disc (305) is slidably connected to the transmission shaft (303) by means of a key, a spring I (306) is connected between the clamping disc (305) and the mounting cover (204), the left and right parts of the clamping disc (305) are slidably connected, a spring II (308) is sleeved on the transmission shaft (303) between the clamping disc (305) and the transmission box (302), and clamping blocks (307) are evenly spaced at eccentric positions on the left side of the clamping disc (305), and the clamping blocks (307) are clamped into the grinding disc (304).

5. A wall surface grinding device for building decoration as claimed in claim 4, characterized in that: It also includes a pushing portion (5), which is symmetrically fixedly arranged on the right side of the mounting cover (204) in the front and rear directions, and includes a mounting block (501) symmetrically arranged on the right side of the mounting cover (204), and a wedge block (502) slidably mounted on the mounting block (501).

6. A wall surface grinding device for building decoration as claimed in claim 5, characterized in that: The invention also comprises a vibration part (6), wherein the vibration part (6) is arranged on the right side of the mounting cover (204), and the vibration part (6) comprises a transmission pulley group (601), an eccentric wheel (602), a large transmission wheel (603) and a small transmission wheel (604). The transmission pulley group (601) is evenly arranged on the right side of the mounting cover (204) for rotation, wherein the transmission pulley group (601) comprises a small belt pulley, a large belt pulley and a transmission belt, wherein the transmission belt is wound between the small belt pulley and the large belt pulley, the eccentric wheel (602) is arranged on the left side of the large belt pulley in the transmission pulley group (601), the small transmission wheel (604) is arranged on the left side of the small belt pulley, and the large transmission wheel (603) is arranged at the center of the right side of the clamping plate (305).

7. A wall surface grinding device for building decoration as claimed in claim 6, characterized in that: It also comprises a dust suction part (7), the dust suction part (7) comprising a dust suction pipe (702) installed between the installation cover (204) and the connecting head (107), and a dust inlet hole (701) is provided on the grinding disc (304) on the left side of the dust suction pipe (702).

8. The wall surface grinding device for building decoration according to claim 7, characterized in that: The edge of the grinding block (402) is wrapped with a protective layer.

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