Brushless angle grinder

Abstract

This invention relates to a brushless angle grinder, comprising a motor assembly and a motor housing housing the motor assembly. The motor housing has a base ring at its end. The motor housing is selectively adapted to a first rear cover formed by two half-shells or a second rear cover in the shape of a cylinder. The motor housing has a first mounting portion distributed circumferentially on the base ring and a second mounting portion extending from the end face of the base ring. The first rear cover has a first positioning portion disposed on the inner wall and a first locking portion mounted on the inner wall. The second rear cover has a second positioning portion disposed on the inner wall and a second locking portion mounted on the inner wall. The first positioning portion and the second positioning portion are connected to the first mounting portion, and the first locking portion and the second locking portion are connected to the second mounting portion.

Description

[Technical Field]

[0001] This invention relates to the field of power tool technology, and in particular to a brushless angle grinder with an improved housing connection structure. [Background Technology]

[0002] A brushless angle grinder is a tool that uses a brushless motor to drive an output accessory to perform grinding and cutting operations on a workpiece. Its housing includes a motor housing that houses the motor and a rear cover connected to the motor housing. Users typically choose different types of brushless angle grinders depending on the working environment. Therefore, brushless angle grinders have both AC and DC power supply options. In this case, the type of rear cover also differs depending on the power supply type: DC brushless angle grinders usually have a half-type rear cover (i.e., the rear cover is composed of two identical half-shells joined together) spliced ​​with the main housing, while AC brushless angle grinders typically use a cylindrical rear cover assembled with the main housing.

[0003] Currently, when installing Half-type and cylindrical rear covers onto the main housing, different structural forms of motor housings are required to be compatible with the rear covers. In other words, there is currently no motor housing that can be used for both Half-type and cylindrical rear covers. Therefore, multiple sets of molds must be designed when producing motor housings, and motor housings with different structures can only be manufactured separately. This not only increases the design and manufacturing time, but also inevitably increases the investment in research and development costs.

[0004] Therefore, it is determined that it is necessary to provide an improved brushless angle grinder to overcome the shortcomings of the prior art. [Summary of the Invention]

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a brushless angle grinder with a composite housing connection structure, which has the advantages of strong adaptability and low manufacturing cost.

[0006] The present invention solves the problems of the prior art by adopting the following technical solution: a brushless angle grinder, comprising a motor assembly and a motor housing housing the motor assembly, wherein the motor housing is provided with a base ring at its end, and the motor housing is selectively adapted to a first rear cover formed by two half-shells or a second rear cover in the shape of a cylinder, the motor housing having a first mounting portion distributed circumferentially on the base ring and a second mounting portion extending from the end face of the base ring, the first rear cover having a first positioning portion disposed on the inner wall and a first locking portion mounted on the inner wall, the second rear cover having a second positioning portion disposed on the inner wall and a second locking portion mounted on the inner wall, the first positioning portion and the second positioning portion being connected to the first mounting portion, and the first locking portion and the second locking portion being connected to the second mounting portion.

[0007] A further improvement is as follows: the first mounting part has a mounting groove on the circumferential surface of the base ring, and the first positioning part is fixed in the mounting groove.

[0008] A further improvement is as follows: the second mounting part has a through hole that penetrates radially, the first rear cover includes a first half shell and a second half shell that are connected to each other, the first locking part is provided with a first pin and a second pin on both the first half shell and the second half shell, the first pin and the second pin are spaced apart, and the first pin and the second pin pass through the through hole.

[0009] A further improvement is as follows: the motor housing is recessed from the circumferential surface of the base ring to form an auxiliary mounting part, and the first rear cover has a retaining plate protruding from its inner wall, the retaining plate being held in place by the auxiliary mounting part.

[0010] A further improvement is as follows: the auxiliary mounting part has a first slot formed on the circumferential surface of the base ring and a second slot communicating with the first slot; the locking plate includes a first locking plate extending from the inner wall of the first rear cover and a second locking plate connected to the first locking plate; the first locking plate is engaged with the first slot; and the second locking plate is engaged with the second slot.

[0011] A further improvement is as follows: the first mounting portion has a recess formed on the circumferential surface of the base ring, and the second rear cover has a second positioning portion provided on the inner wall. The second positioning portion is a protrusion extending from the inner wall of the second rear cover, and the protrusion and the recess are locked together.

[0012] A further improvement is that the mounting groove extends radially from the surface of the recess, and the mounting groove blocks the recess.

[0013] A further improvement is as follows: the second mounting part is provided with an axially penetrating machining area, the machining area including a blind hole, and the second rear cover has a connecting hole penetrating the second locking part, the connecting hole being connected to the blind hole by a screw.

[0014] A further improvement is that the processing area and the through hole at least partially intersect.

[0015] A further improvement is as follows: the motor housing has a gripping part, and the projection of the through hole on the end face of the gripping part is located inside the projection of the base ring on the end face of the gripping part.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. By opening the first mounting part and the second mounting part on the motor housing, the installation of the Half-type rear cover or the cylindrical rear cover can be realized simultaneously. Therefore, only one set of motor housing molds needs to be designed to meet the assembly requirements of AC brushless angle grinders and DC brushless angle grinders, which can greatly reduce production costs.

[0018] 2. The first mounting part is provided with mounting grooves and recesses with overlapping contours, and the second mounting part is provided with intersecting through holes and blind holes. The first mounting part and the second mounting part are integrated as a single part with multiple connection structures, which realizes multi-purpose connection while ensuring the compactness of the overall structure of the motor housing.

[0019] 3. Compared with existing motor housings, the motor housing of this invention only requires minor processing to connect to different rear covers, making it easier to manufacture. [Image Description]

[0020] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings:

[0021] Figure 1 This is a three-dimensional schematic diagram of a brushless angle grinder with a first rear cover and a second rear cover installed in a preferred embodiment of the present invention;

[0022] Figure 2 yes Figure 1 A partial sectional view of the brushless angle grinder shown;

[0023] Figure 3 yes Figure 1 The diagram shows the structure of the motor housing in the brushless angle grinder.

[0024] Figure 4 yes Figure 3 An enlarged view of part A in the motor housing shown;

[0025] Figure 5 yes Figure 3 The motor housing shown Figure 1 The diagram shows the fit of the first rear cover;

[0026] Figure 6 yes Figure 5 An enlarged view of part B in the first rear cover shown;

[0027] Figure 7 yes Figure 3 The motor housing shown Figure 1 The diagram shows the fit of the second rear cover;

[0028] Figure 8 yes Figure 7 An enlarged view of section C in the second rear cover shown. [Detailed Implementation]

[0029] 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.

[0030] Please refer to Figures 1 to 4 As shown, an embodiment of the present invention relates to a brushless angle grinder 100, which includes a housing 200, a motor assembly 4 housed in the housing 200, a transmission assembly 5 driven by the motor assembly 4, and a top tool 6 that rotates with the transmission assembly 5. The housing 200 includes a head shell 1, a motor shell 2, and a first rear cover 3 or a second rear cover 7 adapted to the motor shell 2. The head shell 1 is divided into a first cavity 11 and a second cavity 12. An end cap 13 is provided at the lower end of the second cavity 12 to form a seal with the head shell 1, preventing dust from entering the head shell 1. The motor shell 2 is connected to the right end of the head shell and is divided into a grip 21 and a stop 22. When using the brushless angle grinder 100, the operator can place their palm on the grip 21. On the surface, the back of the hand abuts against the stop 22, which can prevent the brushless angle grinder 100 from falling off; furthermore, the right end of the motor housing 2 is selectively connected to the first rear cover 3 or the second rear cover 7, that is, when the brushless angle grinder 100 is an AC tool, the first rear cover 3 can be selected, while when the brushless angle grinder 100 is a DC tool, the second rear cover 7 can be selected. The first rear cover 3 is formed by the first half shell 3a and the second half shell 3b covering each other, and the second rear cover 7 has a cylindrical structure.

[0031] Furthermore, the motor assembly 4 is used to receive current from the power supply to drive the transmission assembly 5 to operate, including a stator 41 and a rotor 42: the stator 41 is a hollow cylindrical shape, which is held inside the motor housing 2; the rotor 42 is received inside the stator 41, the rotor 42 has a drive shaft 421, the left and right ends of the drive shaft 421 are supported by bearings; a fan 43 is installed at the left end of the drive shaft 421, and the operation of the fan 43 can draw external airflow into the housing 200 to cool the motor assembly 4.

[0032] The transmission assembly 5 receives the force generated by the motor assembly 4 and transmits it to the top tool 6. The transmission assembly 5 includes: a first bevel gear 51, which is installed at the left end of the drive shaft 421 and located inside the first cavity 11, and is limited and fixed by a lock nut; a second bevel gear 52, which is installed inside the second cavity 12 and meshes with the first bevel gear 51; and an output shaft 53, which is installed inside the second bevel gear 52 and is driven to rotate by the second bevel gear 52. The top tool 6 is installed at the lower end of the output shaft 53 and includes a working wheel 61 for processing the workpiece and a pressure plate 62 for fixing the working wheel 61. The working wheel 61 can be a grinding disc, a cutting disc, etc.

[0033] Next, the motor housing 2 is described. A base ring 23 is machined at the right end of the gripping part 21. The base ring 23 is a ring-like structure with a certain length in the left-right direction. Four first mounting parts 24 are provided on the surface of the base ring 23. Viewed from the right side, the four first mounting parts 24 are formed at the upper front, lower front, upper rear, and lower rear corners of the base ring 23. The first mounting part 24 is not a single mounting structure, but a composite mounting structure composed of mounting grooves 241 and recesses 242. Specifically, the mounting groove 241 extends from the base ring... The surface of 23 extends inward and is composed of three planes: a first contact surface 241a, a second contact surface 241b, and a third contact surface 241c. The first contact surface 241a and the third contact surface 241c are distributed on both sides of the second contact surface 241b, and the angles they form with the second contact surface 241b are equal. The recess 242 is provided on the surface of the base ring 23. When viewed from the right side, the outline of the recess 242 is an arc curve. The mounting groove 241 is opened in the central part of the recess 242. That is to say, the recess 242 is divided into two halves by the mounting groove 241.

[0034] When machining the first mounting part 24, a recess 242 can first be engraved along the circumferential surface of the base ring 23. Furthermore, when machining the mounting groove 241, it is only necessary to carve out the first contact surface 241a, the second contact surface 241b, and the third contact surface 241c in sequence from the center of the recess 242 along the radial direction. In fact, the entire machining process of the first mounting part 24 is relatively small because the first mounting part 24 is formed by radially slotting on the circumferential surface of the base ring 23 without increasing the spatial volume of the base ring 23. Therefore, the overall structure of the first mounting part 24 is relatively compact.

[0035] Furthermore, the base ring 23 is provided with second mounting portions 25 at its upper and lower ends. Each second mounting portion 25 includes a fixing block 251, a through hole 252 formed in the fixing block 251, and a blind hole 254. The fixing block 251 protrudes from the right end face of the base ring 23. The front and rear end faces of the fixing block 251 are perforated by the through hole 252. The cross-section of the through hole 252 must be circular, not a broken arc. That is, the projection of the through hole 252 onto the right end face of the gripping portion 21 must be inside the projection of the base ring 23 onto the right end face of the gripping portion 21. To achieve the multi-functionality of the fixing block 251, holes are also required in the left and right directions of the fixing block 251. During processing, the fixing block 251... The right end face of 1 is the starting surface, and a hole is drilled to the left. During the drilling process, it will intersect with the through hole 252. This intersection is named the avoidance area 253. The hole is drilled to the left again from the avoidance area 253, and a blind hole 254 is formed on the solid to the left of the avoidance area 253. Based on this, the space formed by the combination of the avoidance area 253 and the blind hole 254 is defined as the processing area 255. Since the avoidance area 253 is a common part of the processing area 255 and the blind hole 254, the through hole 252 and the blind hole 254 cannot be installed at the same time. However, the setting of the avoidance area 253 makes the fixing block 251 more compact in structure, which is conducive to the miniaturization of the brushless angle grinder 100.

[0036] On the front and rear sides of the second mounting part 25, the base ring 23 is provided with auxiliary mounting parts 26. The auxiliary mounting parts 26 are composed of a first slot 261 and a second slot 262: the opening of the first slot 261 is elongated, and the opening of the second slot 262 is square. The width of the opening of the second slot 262 in the left-right direction is greater than that of the first slot 261. The opening of the second slot 262 extends into the base ring 23 at a certain angle relative to the surface of the base ring 23. That is to say, the space formed by the second slot 262 is located inside the base ring 23 and communicates with the first slot 261.

[0037] Furthermore, the process of installing the first rear cover 3 onto the motor housing 2 is described below; please refer to [link / reference]. Figures 5 to 6 As shown: The first half shell 3a and the second half shell 3b in the first rear cover 3 are both provided with a first positioning part 31. Specifically, there are four first positioning parts 31, which are located at the upper left and lower left ends of the first half shell 3a and the upper left and lower left ends of the second half shell 3b, respectively. Taking the first half shell 3a as an example, the first positioning part 31 protrudes from the inner wall of the first half shell 3a and forms a first abutment surface 311, a second abutment surface 312 and a third abutment surface 313. The included angles formed by the first abutment surface 311, the third abutment surface 313 and the second abutment surface 312 are equal.

[0038] Furthermore, the first rear cover 3 is provided with a first locking part 32. The first locking part 32 is not a single part, but is formed by the combination of multiple parts. Specifically, the lower left end of the first half-shell 3a has a base 321 and a first pin 322 connected to the base 321 protruding from the inner wall. At the upper left end, spaced apart from the first pin 322, a second pin 323 protrudes from the inner wall. The lower left end of the second half-shell 3b is provided with the second pin 323, and the upper left end of the second half-shell 3b is provided with the base 321 and the first pin 322. Thus... The base 321 and the first pin 322 on the first half-shell 3a, and the corresponding second pin 323 on the second half-shell 3b, form the first locking part 32. Similarly, the second pin 323 on the first half-shell 3a and the corresponding base 321 and the first pin 322 on the second half-shell 3b also form the first locking part 32. The first pin 322 and the second pin 323 are respectively provided with a first pin hole 322a and a second pin hole 323b. The diameter of the first pin hole 322a is equal to the diameter of the second pin hole 323b.

[0039] On the other side of the first positioning part 31, the first rear cover 3 is provided with a retaining plate 33. The retaining plate 33 includes a first retaining plate 331 and a second retaining plate 332. The first retaining plate 331 extends from the inner wall of the first rear cover 3, and its width in the left-right direction is equal to that of the first slot 261. The second retaining plate 332 is connected to the end face of the first retaining plate 331, and its width in the left-right direction is equal to that of the second slot 262.

[0040] When installing the first rear cover 3 onto the motor housing 2, the following operations are required: When inserting the first positioning part 31 into the mounting slot 241, the first abutment surface 311, the second abutment surface 312, and the third abutment surface 313 should contact the first contact surface 241a, the second contact surface 241b, and the third contact surface 241c, respectively; When inserting the retaining plate 33 into the auxiliary mounting part 26, the first retaining plate 331 and the second retaining plate 332 should engage with the first slot 261 and the second slot 262, respectively; When fixing the first locking part 32 to the second mounting part 25, the first pin 322 and the second pin 323 on the two half-shells should be aligned with the through hole 252 and inserted simultaneously. With the first pin 322 and the second pin 323 aligned, screws should be driven into the first pin hole 322a and the second pin hole 322b. At this point, the first rear cover 3 has been installed.

[0041] The following describes the process of installing the second rear cover 7 into the motor housing 2. Please refer to [link / reference]. Figures 7 to 8As shown: The second rear cover 7 has a cylindrical structure, and its inner wall is provided with a second positioning part 71. The second positioning part 71 extends from the left end wall of the second rear cover 7 to the right. The cross-sectional shape of the second positioning part 71 is a protrusion 711, and the outline of the protrusion 711 is preferably an arc curve. Further, a second locking part 72 is provided at a distance between the inner wall of the second rear cover 7 and the second positioning part 71. The second locking part 72 is a cylinder extending from the left end to the right end of the second rear cover 7. A connecting hole 721 passes through the interior of the locking part 72, and the center line of the second locking part 72 coincides with the center line of the blind hole 254.

[0042] When installing the motor housing 2 of the second rear cover 7, the following operation is required: align the protrusion 711 on the second positioning part 71 with the recess 242 and insert it so that their outlines coincide. At this time, the connecting hole 721 in the second locking part 72 is aligned with the blind hole 254. Simply drive the screw into the connecting hole 721 to connect the connecting hole 721 and the blind hole 254 in series.

[0043] In this embodiment, the motor housing 2 can be installed with both the first rear cover 3 and the second rear cover 7. That is to say, both AC brushless angle grinders and DC brushless angle grinders can use the motor housing 2 in this embodiment. Therefore, only three sets of molds are needed to manufacture the housings of AC brushless angle grinders and DC brushless angle grinders, which will inevitably reduce the R&D cost significantly. Moreover, the motor housing 2 only needs to be processed with minor machining such as slotting and drilling on the existing structure, without major modifications. Therefore, the manufacturing of the motor housing 2 is relatively simple. In addition, the mounting groove 241 and recess 242 on the first mounting part 24, and the through hole 252 and processing area 255 on the second mounting part 25 have overlapping parts, which realizes multi-purpose connection while ensuring the compactness of the overall structure of the motor housing.

[0044] This invention is not limited to the specific embodiments described above. Those skilled in the art will readily understand that many alternative solutions to the brushless angle grinder of this invention exist without departing from the principles and scope of the invention. The scope of protection of this invention is defined by the claims.

Claims

1. A brushless angle grinder (100), comprising a motor assembly (4) and a motor housing (2) housing the motor assembly (4), the motor housing (2) having a base ring (23) at one end; characterized in that: The motor housing (2) is adaptable to one of a first rear cover (3) formed by two half-shells and a cylindrical second rear cover (7). The motor housing (2) has a first mounting portion (24) distributed circumferentially on the base ring (23) and a second mounting portion (25) extending from the end face of the base ring (23). The first rear cover (3) has a first positioning portion (31) on the inner wall and a first locking portion (32) mounted on the inner wall. The second rear cover (7) has a second positioning portion (71) on the inner wall and a second locking portion (72) mounted on the inner wall. The first positioning portion (31) and the second positioning portion (71) are connected to the first mounting portion (24). The second mounting portion (25) has a radially penetrating through hole (252) and an axially penetrating processing area (255). The first locking portion (32) is connected to the through hole (252), and the second locking portion (72) is connected to the processing area (255).

2. The brushless angle grinder (100) according to claim 1, characterized in that: The first mounting part (24) has a mounting groove (241) provided on the circumferential surface of the base ring (23), and the first positioning part (31) is fixed in the mounting groove (241).

3. The brushless angle grinder (100) according to claim 2, characterized in that: The first rear cover (3) includes a first half shell (3a) and a second half shell (3b) connected to each other. The first locking part (32) is provided with a first pin (322) and a second pin (323) on both the first half shell (3a) and the second half shell (3b). The first pin (322) and the second pin (323) are spaced apart and pass through the through hole (252).

4. The brushless angle grinder (100) according to claim 3, characterized in that: The motor housing (2) is recessed from the circumferential surface of the base ring (23) to form an auxiliary mounting part (26), and the first rear cover (3) has a retaining plate (33) protruding from its inner wall, which is held in place by the auxiliary mounting part (26).

5. The brushless angle grinder (100) according to claim 4, characterized in that: The auxiliary mounting part (26) has a first slot (261) formed on the circumferential surface of the base ring (23) and a second slot (262) communicating with the first slot (261). The retaining plate (33) includes a first retaining plate (331) extending from the inner wall of the first rear cover (3) and a second retaining plate (332) connected to the first retaining plate (331). The first retaining plate (331) is engaged with the first slot (261), and the second retaining plate (332) is engaged with the second slot (262).

6. The brushless angle grinder (100) according to claim 5, characterized in that: The first mounting portion (24) has a recess (242) formed on the circumferential surface of the base ring (23), and the second rear cover (7) has a second positioning portion (71) provided on the inner wall. The second positioning portion (71) is a protrusion (711) extending from the inner wall of the second rear cover (7), and the protrusion (711) and the recess (242) are locked together.

7. The brushless angle grinder (100) according to claim 6, characterized in that: The mounting groove (241) extends radially from the surface of the recess (242) and the mounting groove (241) blocks the recess (242).

8. The brushless angle grinder (100) according to claim 6, characterized in that: The processing area (255) includes a blind hole (254), and the second rear cover (7) has a connecting hole (721) that penetrates the second locking part (72), the connecting hole (721) being connected to the blind hole (254) by a screw.

9. The brushless angle grinder (100) according to claim 8, characterized in that: The processing area (255) and the through hole (252) at least partially intersect.

10. The brushless angle grinder (100) according to claim 9, characterized in that: The motor housing (2) has a gripping part (21), and the projection of the through hole (252) on the end face of the gripping part (21) is located inside the projection of the base ring (23) on the end face of the gripping part (21).

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