Electric grinding tool machine

Abstract

An electric grinding tool machine includes a holding body, a grinding disc and a battery. A tool shaft connecting the grinding disc is provided in the holding body, a driving component that can rotate the tool shaft when receiving power, and a circuit board electrically connected to the driving component and the battery. The holding body has a battery mounting seat exposed on the outer surface. Among them, the board surface of the circuit board is not perpendicular to the tool shaft, the circuit board and the battery mounting seat are respectively located on two opposite sides of the tool shaft, and the connection line between the circuit board and the battery mounting seat passes through the tool shaft. In the present invention, by changing the position of the circuit board, the height of the holding body is decreased, thereby reducing the center of gravity of the holding body to increase the stability of the grinding operation.

Description

Technical Field

[0001] The present invention relates to an electric grinding tool machine, and more particularly to an electric grinding tool machine with a reduced center of gravity of the holding body. Background Art

[0002] It is found that US 2020230796A, US 2006068689A and US 2018056473A have disclosed the configuration of internal components of an electric grinding tool machine. The internal structure of the existing electric grinding tool machine 50 is as shown in the text Figure 1 depicted. The electric grinding tool machine 50 includes a holding body 51, a grinding disc 52 and a battery 53. The holding body 51 has a tool shaft 511 disposed within the holding body 51 and connected to the grinding disc 52, a driving assembly 512 disposed within the holding body 51 and driving the tool shaft 511 when receiving power, and a circuit board 513 disposed within the holding body 51 and connecting the driving assembly 512 and the battery 53. Among them, since the existing circuit board 513 is disposed at the top of the tool shaft 511 (at the position marked 515), the internal components of the electric grinding tool machine 50 are arranged in a linear up-and-down configuration. That is to say, the height 514 of the existing holding body 51 is equal to the sum of the height of the circuit board 513, the height of the tool shaft 511 and the height of the top of the holding body 51. However, the drawback of the existing configuration is that due to the relatively high height 514 of the existing holding body 51, the center of gravity of the holding body 51 cannot be reduced. When the user operates and moves the electric grinding tool machine 50, the holding body 51 is prone to instability and tipping. Especially when the user operates the existing electric grinding tool machine 50 to grind an upright board surface, it is more difficult to stably control the electric grinding tool machine 50.

[0003] On the other hand, since the existing circuit board 513 is disposed at the top of the tool shaft 511, that is, the circuit board 513 is disposed on the side of the holding body 51 close to the user's palm. When the electric grinding tool machine 50 is operating, the circuit board 513 will receive power and generate heat, causing the temperature on the side of the holding body 51 close to the user's palm to rise. After the electric grinding tool machine 50 is used for a long time, the circuit board 513 will transfer a large amount of heat to the holding body 51, making it difficult for the user to hold the holding body 51, thereby affecting the grinding operation. Summary of the Invention

[0004] The main object of the present invention is to solve the problems derived from the relatively high center of gravity of the holding body caused by the existing circuit board of the electric grinding tool machine being disposed at the top of the tool shaft.

[0005] Another object of the present invention is to solve the problem that after the existing circuit board receives power and generates heat, the temperature of the holding body rises, thereby affecting the comfort of the user when holding the holding body.

[0006] To achieve the above object, the present invention provides an electric grinding tool machine, comprising a holding body, a grinding disc and a battery. A tool shaft connecting the grinding disc is provided in the holding body, a driving component capable of rotating the tool shaft when receiving power, a circuit board electrically connecting the driving component and the battery, and the holding body has a battery mounting seat exposed on the outer surface. Further, the board surface of the circuit board is not perpendicular to the tool shaft, the circuit board and the battery mounting seat are respectively located on two opposite sides of the tool shaft, and the connection line between the circuit board and the battery mounting seat passes through the tool shaft.

[0007] In one embodiment, the holding body is formed with a plurality of ventilation holes, and the plurality of ventilation holes form an air path passing through the circuit board.

[0008] In one embodiment, the holding body is formed with a plurality of ventilation holes, and the plurality of ventilation holes form a first air path passing through the circuit board and a second air path flowing on the side of the driving component not facing the circuit board.

[0009] In one embodiment, the driving component includes a rotor connecting the tool shaft and a stator cooperating with the rotor.

[0010] In one embodiment, the electric grinding tool machine includes an assembly housing provided in the holding body and for providing a setting space for the driving component. The assembly housing includes a tube body and two covers respectively provided on both sides of the tube body.

[0011] In one embodiment, the tool shaft is provided with a counterweight and a fan blade assembled on the counterweight and rotating synchronously with the tool shaft.

[0012] In one embodiment, the counterweight has a first counterweight part and a second counterweight part arranged up and down, the second counterweight part is eccentric relative to the first counterweight part, and the fan blade is provided on the second counterweight part.

[0013] In one embodiment, at least one opening facing the counterweight is formed at one end of the holding body close to the grinding disc.

[0014] In one embodiment, the holding body defines the side where the circuit board is provided as a front side, and the electric grinding tool machine has an operation panel provided on the front side of the holding body and electrically connected to the circuit board.

[0015] In one embodiment, the inner wall surface of the holding body has a placement space facing the driving component and for providing a setting space for the circuit board.

[0016] In one embodiment, a convex portion is formed on the outer surface of the holding body opposite to the placement space, and a commercial label is provided on the convex portion.

[0017] In one embodiment, the battery mounting seat has an insertion opening, and the direction of the insertion opening is perpendicular to the tool axis.

[0018] In one embodiment, the battery mounting seat has an insertion opening, and the direction of the insertion opening is parallel to the tool axis.

[0019] Through the foregoing disclosure of the present invention, compared with the prior art, it has the following characteristics: by changing the position of the circuit board, the circuit board is arranged on the other side of the tool axis that does not face the battery mounting seat, and at the same time, the surface of the circuit board is set not to be perpendicular to the tool axis. In this way, the height of the holding body of the present invention is approximately the sum of the height of the tool axis and the height of the top of the holding body, which is lower than that of the holding body in the prior art, thereby reducing the center of gravity of the holding body and enabling the user to operate the holding body more stably. On the other hand, since the circuit board of the present invention is no longer arranged on the side of the tool axis that does not face the grinding disc, the user will not be affected by the temperature rise of the circuit board when grasping the holding body. Description of the Drawings

[0020] Figure 1 , Schematic cross-sectional view of an existing electric grinding tool machine;

[0021] Figure 2 , Schematic three-dimensional structure view of an embodiment of the present invention;

[0022] Figure 3 , Schematic exploded view of an embodiment of the present invention;

[0023] Figure 4 , Schematic cross-sectional view of an embodiment of the present invention (I);

[0024] Figure 5 , Schematic cross-sectional view of an embodiment of the present invention (II);

[0025] Figure 6 , Schematic unit view of an embodiment of the present invention;

[0026] Figure 7 , Schematic three-dimensional structure view of another embodiment of the present invention;

[0027] Figure 8 , Schematic cross-sectional view of another embodiment of the present invention.

[0028]

Symbol Description

[0029] 10: Electric grinding tool machine

[0030] 11: Holding body

[0031] 101: Height

[0032] 111: Head

[0033] 112: Neck

[0034] 113: Shoulder

[0035] 114: Tool shaft

[0036] 115: Driving component

[0037] 116: Circuit board

[0038] 117: Counterweight body

[0039] 118: First counterweight part

[0040] 119: Second counterweight part

[0041] 120: Extension direction

[0042] 121: Battery mounting seat

[0043] 122: Connection wire

[0044] 123: Vent hole

[0045] 124: First air passage

[0046] 125: Opening

[0047] 126: Fan blade

[0048] 127: Second air passage

[0049] 132: Rotor

[0050] 133: Stator

[0051] 134: Connecting post

[0052] 135: First bearing

[0053] 136: Second bearing

[0054] 137: Front side

[0055] 138: Insertion opening

[0056] 139: Conductive terminal

[0057] 140: Direction

[0058] 141: Shaft rod extension direction

[0059] 142: Direction

[0060] 143: Placing space

[0061] 144: Convex part

[0062] 15: Grinding disc

[0063] 151: Body

[0064] 152: Assembly

[0065] 16: Battery

[0066] 161: Boss

[0067] 162: Conductive hole

[0068] 17: Connector housing

[0069] 171: Tube body

[0070] 172: Cover

[0071] 173: Connector

[0072] 18: Operation panel

[0073] 181: Control signal

[0074] 50: Electric grinding tool machine

[0075] 51: Holding body

[0076] 511: Tool shaft

[0077] 512: Driving component

[0078] 513: Circuit board

[0079] 514: Height

[0080] 515: Top of tool shaft

[0081] 52: Grinding disc

[0082] 53: Battery Detailed implementation mode

[0083] The detailed description and technical content of the present invention are described as follows in conjunction with the accompanying drawings:

[0084] Please refer to Figures 2 to 5, the present invention provides an electric grinding tool machine 10, which includes a holding body 11, a grinding disc 15 and a battery 16. In one embodiment, the holding body 11 includes a head 111, a neck 112 and a shoulder 113. The head 111 is for the user to hold to control the holding body 11. Also, the neck 112 extends from one side of the head 111, and the diameter of the neck 112 is smaller than the diameter of the head 111 and also smaller than the diameter of the shoulder 113. In addition, the shoulder 113 is connected to the neck 112 and extends in a direction away from the side where the neck 112 faces the head 111. The diameter of the shoulder 113 gradually increases from the side where the shoulder 113 faces the neck 112 to the side where the shoulder 113 is away from the neck 112, so that the shoulder 113 presents a flared shape. Also, the side of the shoulder 113 that is not connected to the neck 112 faces the grinding disc 15, and the diameter of the side of the shoulder 113 away from the neck 112 is set corresponding to the diameter of the grinding disc 15.

[0085] Furthermore, the holding body 11 further includes a tool shaft 114, a driving component 115, and a circuit board 116. Specifically, the tool shaft 114 is disposed within the holding body 11, and one end of the tool shaft 114 is connected to the grinding disc 15. In one embodiment, the grinding disc 15 includes a body 151 and an assembly 152 connecting the body 151, and the tool shaft 114 is connected to the assembly 152. Additionally, in one embodiment, the tool shaft 114 is connected to a counterweight 117 facing the grinding disc 15, and the counterweight 117 has a first counterweight portion 118 and a second counterweight portion 119 arranged vertically. The second counterweight portion 119 is disposed below the first counterweight portion 118, and the second counterweight portion 119 is eccentric relative to the first counterweight portion 118. Accordingly, through the arrangement of the counterweight 117, the tool shaft 114 can drive the grinding disc 15 to generate an eccentric rotation stroke. On the other hand, the driving component 115 is connected to the tool shaft 114 and is located within the holding body 11. The driving component 115 can be an electric motor, and after receiving power, the driving component 115 drives the tool shaft 114 to rotate. Also, the circuit board 116 is electrically connected to the driving component 115 and the battery 16, and the circuit board 116 is used to control the operation of the driving component 115. In this embodiment, the circuit board 116 can be fixed to the inner wall surface of the holding body 11, such that the circuit board 116 can be disposed at the neck 112 position of the holding body 11. More specifically, the circuit board 116 has an extending direction 120 along its board surface, and the board surface is the plane on which electronic components are arranged on the circuit board 116. The extending direction 120 of the circuit board 116 is not perpendicular to the tool shaft 114. In one embodiment, the extending direction 120 of the circuit board 116 and the tool shaft 114 can also be arranged in parallel to reduce the height of the holding body 11. On the other hand, the holding body 11 has a battery mounting seat 121 exposed on the surface, and the battery mounting seat 121 is used to connect the battery 16, such that the power of the battery 16 can be transmitted to the circuit board 116 through the battery mounting seat 121. Also, the battery mounting seat 121 is disposed on the side of the tool shaft 114 not facing the circuit board 116, that is, the battery mounting seat 121 and the circuit board 116 are respectively located on two opposite sides of the tool shaft 114, such that the connection line 122 between the circuit board 116 and the battery mounting seat 121 passes through the tool shaft 114.

[0086] Accordingly, the present invention changes the position of the circuit board 116, so that the height 101 of the holding body 11 can subtract the height of the circuit board 116 and is approximately equal to the sum of the height of the tool shaft 114 and the height of the top of the holding body 11, thereby reducing the height 101 of the holding body 11 and achieving the purpose of lowering the center of gravity of the holding body 11. Through the present invention, when the user operates the electric grinding tool 10, due to the decrease in the center of gravity of the holding body 11, the holding body 11 is not easily toppled when displaced by the operation and can be more stably close to the grinding surface. Especially when the user grinds an upright board surface, the user does not need to spend a lot of effort to resist the gravity to control the holding body, so that the holding body 11 can be close to the board surface, and the grinding quality of the electric grinding tool 10 can be improved for the convenience of the user. Furthermore, since the circuit board 116 of the present invention is no longer disposed at the head 111 of the holding body 11, the user's hand holding the head 111 is not affected by the temperature of the circuit board 116, which is convenient for the user to operate.

[0087] Continuing from the above, please refer to Figures 2 to 5, in one embodiment, to improve the heat dissipation effect of the circuit board 116, the holding body 11 is formed with a plurality of ventilation holes 123, and these ventilation holes 123 are located at the position between the drive assembly 115 and the circuit board 116. When the internal air flow of the electric grinding tool 10 changes, these ventilation holes 123 form a first air path 124 for heat exchange with the circuit board 116. For example, these ventilation holes 123 can be arranged on two opposite sides of the holding body 11. Those ventilation holes 123 on one side of the holding body 11 can allow external air to enter the holding body 11, pass through the circuit board 116, and then be discharged from those ventilation holes 123 on the other side of the holding body 11, thereby enabling the circuit board 116 to dissipate heat. In yet another embodiment, these ventilation holes 123 can also be located at the position between the drive assembly 115 and the battery mounting base 121. In this way, these ventilation holes 123 can also form a second air path 127 passing through the drive assembly 115. Further, for example, these ventilation holes 123 can also be respectively arranged on two opposite sides of the holding body 11. Those ventilation holes 123 on one side of the holding body 11 allow gas to enter from the outside. Then, the air will flow on the side of the drive assembly 115 that does not face the circuit board 116 and be discharged from those ventilation holes 123 on the other side of the holding body 11. In this way, when the drive assembly 115 is driven to operate, the heat energy of the drive assembly 115 can be dissipated through the air coming from the second air path 127, thereby avoiding the situation that the temperature of the head 111 of the holding body 11 is too high and difficult for the user to hold. At the same time, it also reduces the heat energy radiation of the drive assembly 115 to the circuit board 116 and reduces the problems of damage to the life and use stability of the circuit board 116 due to accumulated heat. Also, in this embodiment, when the battery 16 is plugged into the battery mounting base 121, the air in the second air path 127 can not only provide heat dissipation for the drive assembly 115 but also perform heat exchange on the heat energy generated by the battery 16 during power supply. It should be noted that the air flow directions of the first air path 124 and the second air path 127 described herein are only for illustrative purposes and not for limiting this case.

[0088] In addition, the tool shaft 114 has a fan blade 126 assembled on the counterweight 117. The fan blade 126 is arranged on the second counterweight portion 119 and is driven by the tool shaft 114, thereby enabling the fan blade 126 to rotate synchronously with the tool shaft 114. In another embodiment, the holding body 11 is formed with at least one opening 125 facing the counterweight 117 near one end of the grinding disc 15, and the opening 125 can allow gas to enter the holding body 11 from the outside.

[0089] On the other hand, please refer to Figures 2 to 5, In one embodiment, the drive assembly 115 includes a rotor 132 and a stator 133. Among them, the rotor 132 is connected to the tool shaft 114. After being affected by magnetic force, the rotor 132 starts to rotate, thereby driving the rotation of the tool shaft 114. In addition, the stator 133 is disposed around the rotor 132 and cooperates with the rotor 132. The specific structure of the stator 133 and the cooperation mode between the stator 133 and the rotor 132 are techniques well known to those with ordinary knowledge in the art, and will not be elaborated herein.

[0090] Furthermore, the electric grinding tool machine 10 includes an assembly housing 17 provided with the drive assembly 115 therein. The assembly housing 17 is located within the grip body 11. The assembly housing 17 includes a tube body 171 and two covers 172 respectively disposed on both sides of the tube body 171. More specifically, the tube body 171 is provided for the stator 133 and the rotor 132 to be disposed therein. In one embodiment, the stator 133 is fixed on the tube body 171. In another embodiment, the stator 133 is formed with at least one connecting post 134, and the connecting post 134 is assembled to one of the covers 172, so that the stator 133 can be fixed within the tube body 171. Also, the two covers 172 are used to close the tube body 171, thereby preventing the dust generated during grinding of the electric grinding tool machine 10 from entering the drive assembly 115. In one embodiment, each cover 172 includes at least one connecting member 173, and the connecting member 173 can fix the cover 172 and the tube body 171 in a screwed manner. In another embodiment, the drive assembly 115 includes at least one first bearing 135 disposed on the tool shaft 114. The first bearing 135 can be disposed on the side of the tool shaft 114 facing one of the covers 172, and the first bearing 135 is used to reduce the frictional force generated when the tool shaft 114 rotates. On the other hand, in one embodiment, at least one second bearing 136 can be provided on the tool shaft 114 and located on the weight 117. The second bearing 136 assists the weight 117 in reducing the frictional force when rotating under the action of the tool shaft 114.

[0091] On the other hand, please refer back to Figures 3 to 6 , In one embodiment, the grip body 11 defines a front side 137 on the side where the circuit board 116 is provided. The electric grinding tool machine 10 has an operation panel 18 on the front side 137 of the grip body 11. The operation panel 18 is electrically connected to the circuit board 116. After being operated, the operation panel 18 generates a control signal 181 to the circuit board 116, and the circuit board 116 controls the drive assembly 115 to start running or stop working according to the content of the control signal 181.

[0092] Furthermore, the battery mounting base 121 of the present invention has an insertion opening 138 and two conductive terminals 139 provided at the insertion opening 138. The battery 16 is formed with a boss 161 protruding toward the battery mounting base 121 and a plurality of conductive holes 162 provided on the boss 161. The two conductive terminals 139 are inserted into two of these conductive holes 162. Further, the insertion opening 138 is defined by the assembling direction of the battery 16. In this article Figure 3 For example, the direction of the insertion opening 138 (such as reference numeral 140) is perpendicular to the axial extension direction of the tool shaft 114 (such as reference numeral 141), that is, the battery 16 is assembled to the battery mounting base 121 in a lateral plugging manner.

[0093] Continuing from the above, in another embodiment, the direction of the insertion opening 138 (such as reference numeral 142) may also be parallel to the axial extension direction of the tool shaft 114 (such as reference numeral 141). In this way, the battery 16 is assembled to the battery mounting base 121 in a straight plugging manner, as shown in this article Figure 7 as shown. Also, please refer to Figure 8 In one embodiment, the holding body 11 of the present invention has a receiving space 143 on the inner wall surface facing the driving component 115. The receiving space 143 is provided at the front side 137 and located at the neck portion 112 position. The receiving space 143 is used for the circuit board 116 to be disposed therein. In one embodiment, the holding body 11 is formed with a convex portion 144 on the outer surface opposite to the receiving space 143. The convex portion 144 can provide a commercial label (not shown in the figure) to be disposed thereon. Among them, the commercial label described in this article can be a trademark or a product model, etc.

Claims

1. An electric grinding tool machine includes a holding body, a grinding disc, and a battery. A tool shaft connecting the grinding disc is provided inside the holding body, a driving component that can rotate the tool shaft when receiving power, and a circuit board electrically connected to the driving component and the battery. The holding body has a battery mounting seat exposed on the outer surface. The electric grinding tool machine is characterized in that: The board surface of the circuit board is not perpendicular to the tool shaft. The circuit board and the battery mounting seat are respectively located on two opposite sides of the tool shaft, and the connection line between the circuit board and the battery mounting seat passes through the tool shaft.

2. The electric grinding tool machine according to claim 1, characterized in that, The holding body is formed with a plurality of ventilation holes, and the plurality of ventilation holes form an air path passing through the circuit board.

3. The electric grinding tool machine according to claim 1, characterized in that, The holding body is formed with a plurality of ventilation holes, and the plurality of ventilation holes form a first air path passing through the circuit board and a second air path flowing on a side of the driving component not facing the circuit board.

4. The electric grinding tool machine according to any one of claims 1 to 3, characterized in that, The driving component includes a rotor connected to the tool shaft and a stator cooperating with the rotor.

5. The electric grinding tool machine according to claim 4, characterized in that, The electric grinding tool machine includes an assembly housing provided inside the holding body and for providing a setting space for the driving component. The assembly housing includes a tube body and two covers respectively provided on two sides of the tube body.

6. The electric grinding tool machine according to any one of claims 1 to 3, characterized in that, The tool shaft is provided with a counterweight and a fan blade assembled on the counterweight and rotating synchronously with the tool shaft.

7. The electric grinding tool machine according to claim 6, characterized in that, The counterweight has a first counterweight part and a second counterweight part arranged up and down. The second counterweight part is eccentric relative to the first counterweight part, and the fan blade is provided on the second counterweight part.

8. The electric grinding tool machine according to claim 7, characterized in that, The holding body is formed with at least one opening facing the counterweight at one end close to the grinding disc.

9. The electric grinding tool machine according to claim 6, characterized in that, The holding body is formed with at least one opening facing the counterweight at one end close to the grinding pad.

10. The electric grinding tool machine according to claim 9, characterized in that, The holding body defines one side where the circuit board is provided as a front side, and the electric grinding tool machine has an operation panel provided on the front side of the holding body and electrically connected to the circuit board.

11. The electric grinding tool machine according to any one of claims 1 to 3, characterized in that, The inner wall surface of the holding body has a placement space facing the driving component and for providing a setting space for the circuit board.

12. The electric grinding tool machine according to claim 11, characterized in that, The outer surface of the holding body opposite to the placement space is formed with a convex part, and the convex part provides a setting space for a commercial label.

13. The electric grinding tool machine according to any one of claims 1 to 3, characterized in that, The battery mounting base has an insertion opening, and the direction of the insertion opening is perpendicular to the tool axis.

14. The electric grinding tool machine according to any one of claims 1 to 3, characterized in that, the battery mounting base has an insertion opening, and the direction of the insertion opening is parallel to the tool axis.

15. The electric grinding tool machine according to any one of claims 1 to 3, characterized in that, the holding body defines a front side where the circuit board is provided, and the electric grinding tool machine has an operation panel provided on the front side of the holding body and electrically connected to the circuit board.

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