Sander

Abstract

The application relates to a sander, which comprises a machine shell, a driving assembly installed in the machine shell and a bottom plate assembly driven by the driving assembly; the sander further comprises a brake ring installed on the machine shell, the machine shell is provided with a volute adjacent to the bottom plate assembly, one end of the brake ring is combined with the volute, and the other end of the brake ring is abutted against the bottom plate assembly; the volute is provided with a mounting portion recessed from the edge; the brake ring comprises a supporting portion installed on the mounting portion and a friction portion abutted against the bottom plate assembly; the friction portion is combined with the supporting portion, and the friction portion and the supporting portion are integrally arranged. According to the application, the brake ring is arranged between the volute of the middle cover and the bottom plate assembly, the friction portion and the supporting portion of the brake ring are integrally arranged, when the brake ring is out of function, only the friction portion needs to be replaced, the cost is reduced, and the replacement is fast.

Description

[Technical Field]

[0001] This invention relates to a sanding machine, and more particularly to a sanding machine that includes a split brake ring. [Background Technology]

[0002] Sanding machines, as commonly used grinding and polishing tools, are mainly used for cleaning, deburring, and smoothing large flat surfaces in building decoration, furniture painting, and bathroom fixtures. A sanding machine mainly consists of a housing, drive assembly, fan assembly, eccentric element, brake ring, and base plate assembly. The housing houses the drive assembly, motor assembly, and eccentric element. The base plate assembly, at least partially outside the housing, is used to attach sandpaper. During machine operation, when the brake ring contacts the base plate assembly, dry friction occurs during the initial rotation of the base plate assembly, slowing down the base plate's rotation and thus improving the service life of the base plate bearings and the base plate itself.

[0003] In the existing sanding machine technology, see Chinese Utility Model Patent CN215659543U, published on January 28, 2022, which discloses: In a sanding machine undergoing braking and deceleration, when the base plate mounting seat continues to swing under inertia, it contacts the friction surface of the friction part of the corresponding elastic brake block, pushing the friction part outward. The adjusting hole contracts, and the deformation of the friction part generates an inward force, thus generating frictional resistance when the outer periphery of the base plate mounting seat contacts the friction surface. The elastic brake blocks then brake the base plate mounting seat, causing it to stop rotating quickly. However, in the above braking scheme, the contact area between the friction surface of the elastic brake block and the base plate mounting seat is small, resulting in poor braking effect. Furthermore, the friction part of the elastic brake block is easily damaged, and replacement is cumbersome and costly.

[0004] Therefore, it is indeed necessary to provide an improved sander to overcome the shortcomings of the existing technology. [Summary of the Invention]

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a sander that is low in cost and easy to replace brake rings.

[0006] The present invention addresses the problems of the prior art by adopting the following technical solution: a sander, comprising a housing, a drive assembly installed within the housing, and a base plate assembly driven by the drive assembly; the sander further comprises a brake ring installed on the housing, the housing having a volute adjacent to the base plate assembly, one end of the brake ring being coupled to the volute and the other end abutting against the base plate assembly, the volute having a recessed mounting portion from its edge, the brake ring comprising a support portion mounted on the mounting portion and a friction portion abutting against the base plate assembly, the friction portion being coupled to the support portion, and the friction portion and the support portion being separately disposed.

[0007] A further improvement is that the support part is made of a first material, and the friction part is made of a second material, wherein the wear resistance of the second material is greater than that of the first material.

[0008] A further improvement is that the height of the friction part is 2mm-6mm, and the volume of the friction part accounts for 10%-40% of the volume of the brake ring.

[0009] A further improvement is as follows: the support part has a connecting part installed on the mounting part and a skeleton connected to the connecting part; the base plate assembly includes a foaming part connected to the driving assembly and an epoxy board installed on the foaming part; the outer ring of the skeleton is located inside the outer ring of the epoxy board; and the friction part abuts against the epoxy board.

[0010] A further improvement is as follows: the drive assembly has a motor axis, the frame has a middle part protruding downward from the end face of the connecting part and an operating part connected to the lower side of the middle part, the inner wall of the middle part is configured to form a first curve convex to the motor axis, the inner wall of the operating part is configured to form a second curve concave to the motor axis, and the connection between the first curve and the second curve is a smooth transition.

[0011] A further improvement is as follows: the operating part has an annular groove recessed from the end face, the friction part is installed in the annular groove, the friction part is exposed downward from the annular groove, and abuts against the epoxy board.

[0012] A further improvement is that the friction part has a flange connected to the annular groove, and the maximum outer diameter of the flange is greater than the maximum inner diameter of the annular groove.

[0013] A further improvement is that the friction part also has an abutment part connected to the flange, the abutment part being interference-fitted with the epoxy board, and the interference fit being 0.3mm-0.8mm.

[0014] A further improvement is as follows: the two ends of the abutment extend outward beyond the lower bottom of the flange to form a notch at the connection between the abutment and the flange, and the two lower wings of the operating part are engaged in the notch.

[0015] A further improvement is as follows: the volute further includes a groove recessed from the end face of the mounting portion, the connecting portion has a protrusion extending from the end face, and the groove is engaged with the protrusion.

[0016] Compared with the prior art, the present invention has the following advantages: By setting a brake ring between the volute and the base plate assembly of the intermediate cover, the friction part and the support part of the brake ring are separately set. When the brake ring fails, only the friction part needs to be replaced, reducing costs and making replacement quick. Specifically, the support part is made of a first material, and the friction part is made of a second material. The wear resistance of the second material is greater than that of the first material, balancing cost and performance. In addition, the inner wall of the intermediate part is configured to form a first curve convex to the motor axis, and the inner wall of the operating part is configured to form a second curve concave to the motor axis. The connection between the first curve and the second curve is a smooth transition. Through the buffer transition structure, force balance is achieved, the wear of the brake ring is uniform and has high flatness, and its service life is improved. Finally, the two ends of the abutment part extend outward beyond the lower bottom of the flange, forming a notch at the connection between the abutment part and the flange. The two lower wings of the operating part are engaged in the notch to prevent the friction part from detaching from the operating part. After the brake ring wears out, it is unnecessary to replace the support part parts; only the friction part needs to be replaced, reducing costs. [Image Description]

[0017] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings:

[0018] Figure 1 This is a cross-sectional schematic diagram of the sanding machine of the present invention;

[0019] Figure 2 yes Figure 1 The exploded structure diagram of the sander shown;

[0020] Figure 3 yes Figure 1 A partial structural schematic diagram of the sander shown;

[0021] Figure 4 yes Figure 1 A magnified view of the sander at point A;

[0022] Figure 5 yes Figure 2 A schematic diagram of the support structure of the sander shown;

[0023] Figure 6 yes Figure 2 The diagram shows the structure of the friction part of the sander. [Detailed Implementation]

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0025] The terminology used in this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. For example, terms such as "upper," "lower," "front," and "rear" that indicate orientation or positional relationship are based solely on the orientation or positional relationship shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device / element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention.

[0026] Please see Figure 1 and Figure 2 As shown, an embodiment of the present invention relates to a sander 100, comprising a housing 1, a drive assembly 2 installed within the housing 1, and a base plate assembly 3 driven by the drive assembly 2. The housing 1 includes a main housing 11 housed within the drive assembly 2 and an intermediate cover 12 connected to the main housing 11. The intermediate cover 12 is located between the main housing 11 and the base plate assembly 3. Abrasive paper is mounted on the base plate assembly 3. Under the action of a drive source, the drive assembly drives the abrasive paper on the base plate assembly to perform sanding and polishing operations on the surface of the workpiece being processed. The dust generated during sanding is drawn into the dust collection box 5 of the sander 100 through the intermediate cover 12, preventing environmental pollution and harm to human health.

[0027] In this embodiment, the sander 100 also includes a brake ring 4 mounted on the intermediate cover 12. The intermediate cover 12 has a volute 121 adjacent to the base plate assembly 3. One end of the brake ring 4 is attached to the volute 121, and the other end abuts against the base plate assembly 3. The layout is ingenious and the structure is compact, without affecting the overall height of the machine. The volute 121 has a mounting portion 1211 recessed from the edge. The brake ring 4 includes a support portion 41 mounted on the mounting portion 1211 and a friction portion 42 abutting against the base plate assembly 3. The friction portion 42 is attached to the support portion 41, and the friction portion 42 and the support portion 41 are separately arranged. With the above-mentioned two-section separate structure of the brake ring, when the brake ring 4 fails, only the friction portion 42 needs to be replaced and then reinstalled on the support portion 41, and the brake ring 4 can continue to work. Replacement is quick, time is shortened, and material waste is avoided, thus reducing costs.

[0028] Specifically, the support part 41 is made of a first material, and the friction part 42 is made of a second material. The first material has greater wear resistance than the second material, which reduces costs while improving braking performance. It should be noted that the support part 41, as the main body, can be made of inexpensive nitrile rubber as its first material, while the friction part 42, as the friction wear part, can be made of fluororubber as its second material. The materials are not limited to these, and the cost reduction and cost-effectiveness are achieved without affecting the braking performance.

[0029] Furthermore, the height of the friction part 42 is 2mm-6mm. This size, while balancing cost, allows for good assembly between the friction part 42 and the support part 41, and also allows for interference contact between the friction part 42 and the base plate assembly 3, achieving a better friction braking effect. In addition, the volume of the friction part 42 accounts for 10%-40% of the volume of the brake ring 4. The volume of the more expensive fluororubber material in the entire brake ring 4 is relatively low, but the part that effectively contacts the friction is the wear-resistant part that contacts the base plate assembly 3.

[0030] Please see Figure 2 and Figure 3 As shown, the volute 121 also includes a groove 1212 recessed from the end face of the mounting portion 1211, and the connecting portion 411 has a protrusion 413 extending from its end face, with the groove 1212 engaging with the protrusion 413. By engaging the protrusion 413 on the brake ring 4 with the groove 1212 of the volute 121, the rotational force caused by friction of the base plate assembly 3 is limited, so that the brake ring 4 can be effectively fixed during operation.

[0031] Please refer to the following: Figure 1 and Figure 2 As shown, the support part 41 has a connecting part 411 installed on the mounting part 1211 and a frame 412 connected to the connecting part 411. The base plate assembly 3 includes a foaming part 31 connected to the drive assembly 2 and an epoxy board 32 installed on the foaming part 31. The outer ring of the frame 412 is located inside the outer ring of the epoxy board 32, and the friction part 42 abuts against the epoxy board 32.

[0032] Please see Figure 1 and Figures 4 to 6 As shown, the drive assembly 2 includes a motor shaft 20 and a motor 21 that rotates along the motor shaft 20. The motor 21 serves as the prime mover of the sander 100 and is housed within the main housing 11. The motor 21 includes a motor shaft 211 for transmitting power to the base plate assembly 3. The motor shaft 211 rotates along the motor shaft 20, which extends substantially in the vertical direction.

[0033] In this embodiment, the frame 412 has a middle part 4121 protruding downward from the end face of the connecting part 411 and an operating part 4122 connected to the lower side of the middle part 4121. The inner wall of the middle part 4121 is formed by a first curve L1 protruding towards the motor axis, and the inner wall of the operating part 4122 is formed by a second curve L2 concave towards the motor axis. With the above arrangement, during the operation of the brake ring, the base plate assembly 3 will generate an upward force on the operating part 4122, while the middle part 4121 will generate a downward force due to gravity. The two forces cancel each other out and form a balance, which facilitates uniform wear of the brake ring 4 and high flatness. In addition, the connection between the first curve L1 and the second curve L2 is a smooth transition, which improves the service life of the brake ring and provides good support rigidity.

[0034] Specifically, the operating part 4122 has an annular groove 4123 recessed from the end face, the friction part 42 is installed in the annular groove 4123, the friction part 42 exposes the annular groove 4123 downward and abuts against the epoxy plate 32, so as to realize the braking and speed reduction of the brake ring 4 against the base plate assembly 3.

[0035] Furthermore, the friction part 42 has a flange 421 connected to the annular groove 4123, and the maximum outer diameter of the flange 421 is larger than the maximum inner diameter of the annular groove 4123. The two are in an interference fit, and the friction force generated by the interference fit must overcome the friction force generated when the base plate assembly 3 rotates and contacts the friction part 42, so as to ensure that the support part 41 and the friction part 42 are always in a relatively fixed state and will not separate, thus affecting the braking effect.

[0036] In addition, the friction part 42 also has an abutment part 422 connected to the flange 421. The abutment part 422 is interference-fitted with the epoxy board 32. The interference fit is 0.3mm-0.8mm, which effectively achieves the friction braking effect of the sander 100.

[0037] Both ends of the abutment portion 422 extend outward beyond the lower bottom of the flange 421 to form a notch 423 at the connection between the abutment portion 422 and the flange 421. Since the friction portion 42 is a consumable part, after the brake ring 4 has been in use for a period of time and the abutment portion 422 is completely worn, the notch 423 prevents friction between the support portion 41 and the epoxy plate 32. Therefore, when replacing the brake ring 4, the user does not need to replace the support portion 41; only the friction portion 42 needs to be quickly replaced, which does not affect braking performance and reduces costs. Furthermore, the lower two wings of the operating portion 4122 are engaged in the notch 423. It should be noted that the lower two wings of the operating portion 4122 form a converging lip, preventing the friction portion 42 from falling out of the annular groove 4123, thus ensuring the normal operation of the brake ring 4.

[0038] This invention is not limited to the specific embodiments described above. Those skilled in the art will readily understand that many alternatives to the sander of this invention exist without departing from its principles and scope. The scope of protection of this invention is defined by the claims.

Claims

1. A sander, comprising a housing, a drive assembly installed within the housing, and a base plate assembly driven by the drive assembly; characterized in that: The sander also includes a brake ring mounted on the housing. The housing has a volute adjacent to the base plate assembly. One end of the brake ring is attached to the volute, and the other end abuts against the base plate assembly. The volute has a recessed mounting portion. The brake ring includes a support portion mounted on the mounting portion and a friction portion abutting against the base plate assembly. The friction portion is attached to the support portion, and the friction portion and the support portion are separately disposed. The support portion has a connecting portion mounted on the mounting portion and a frame connected to the connecting portion. The drive assembly has a motor shaft. The frame has a middle portion protruding downward from the end face of the connecting portion and an operating portion connected to the lower side of the middle portion. The operating portion is connected to the lower side of the middle portion. The inner wall of the middle portion is configured to form a first curve convex to the motor shaft, and the inner wall of the operating portion is configured to form a second curve concave to the motor shaft. The connection between the first curve and the second curve is a smooth transition.

2. The sander according to claim 1, characterized in that: The support portion is made of a first material, and the friction portion is made of a second material, wherein the second material has greater wear resistance than the first material.

3. The sander according to claim 2, characterized in that: The height of the friction part is 2mm-6mm, and the volume of the friction part accounts for 10%-40% of the volume of the brake ring.

4. The sander according to claim 2, characterized in that: The base plate assembly includes a foaming part connected to the drive assembly and an epoxy plate installed on the foaming part. The outer ring of the skeleton is located inside the outer ring of the epoxy plate, and the friction part abuts against the epoxy plate.

5. The sander according to claim 4, characterized in that: The operating part has an annular groove recessed from the end face, the friction part is installed in the annular groove, the friction part is exposed downward from the annular groove, and abuts against the epoxy board.

6. The sander according to claim 5, characterized in that: The friction part has a flange connected to the annular groove, and the maximum outer diameter of the flange is greater than the maximum inner diameter of the annular groove.

7. The sander according to claim 6, characterized in that: The friction part also has an abutting part connected to the flange, the abutting part being interference-fitted with the epoxy board, the interference fit being 0.3mm-0.8mm.

8. The sander according to claim 7, characterized in that: Both ends of the abutment extend outward beyond the lower bottom of the flange to form a notch at the connection between the abutment and the flange, and the two lower wings of the operating part are engaged in the notch.

9. The sander according to claim 4, characterized in that: The volute also includes a groove recessed from the end face of the mounting portion, and the connecting portion has a protrusion extending from the end face, the groove engaging with the protrusion.

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