JP2011142784A - Dc brushless motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a DC brushless motor for which productivity, as well as, dustproofness and waterproofness are improved. <P>SOLUTION: There is provided the DC brushless motor in which a drive circuit board 7, mounted with a drive circuit 12 for switching current to a plurality of drive coils 2, ... is integrally attached to a bracket member 6 protruding from a motor body 5 side. In the DC brushless motor, a board case 13, having a shape and dimensions that correspond to the drive circuit board 7 is provided; the drive circuit board 7, which is combined so as to have a predetermined attaching state for the bracket member 6, is inserted into the substrate case 13; and the drive circuit board 7 is integrally attached to the bracket member 6, with a potting material which is dropped into the board case 13 and then solidified. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a DC brushless motor, and more particularly, to a DC brushless motor that is used for an electric power tool such as an impact driver to improve productivity and dustproofness / waterproofness.

  In general, in an electric power tool such as an impact driver, a motor that operates by supplying power from a battery is used as a rotational drive source. For example, the following power tools are known as conventional techniques including a motor. In this prior art, a motor that operates by supplying power from a battery stored in a battery pack is built in a cylindrical main body portion of a housing. A motor cooling opening is formed in the housing of the main body. A battery pack mounting portion is formed at the lower end of the grip portion extending downward from the main body portion so as to protrude forward, and a circuit storage portion is provided in the vicinity of the front protrusion portion, and an output of the motor is provided in the circuit storage portion. A control circuit board for controlling the torque, the rotational speed, and the like is provided. A dust-proof cushion material that closes the passage space while passing through the control wire is filled and arranged in the passage space for passing the control wire from the control circuit board to the motor. The control circuit board, which is a precision electronic device, is weak against vibrations and dust, as well as against water, due to malfunctions caused by corrosion and short circuits. On the other hand, even if dust or water enters from the motor cooling opening or the like and falls on the grip portion due to gravity, the dust-proof cushion material prevents the dust and water from entering the circuit housing portion. . Thereby, avoidance of the malfunction of the control circuit board by dust or water is achieved (for example, refer patent document 1).

JP 2006-205284 A

  In the prior art described in Patent Document 1, even if dust or water enters through the motor cooling opening formed in the housing of the main body and falls down due to gravity, the dust and water circuit storage unit Dust-proof cushioning material prevents intrusion into the control circuit board and avoids problems caused by dust and water on the control circuit board, which is a precision electronic device.

  By the way, a DC brushless motor having a high rotation function is generally used as a motor as a rotation drive source in an electric power tool such as an impact driver. This DC brushless motor requires an additional drive circuit for switching current to the drive coil, and a drive circuit board on which the drive circuit is mounted is integrally attached to the motor body. This drive circuit board is also a precision electronic device similar to the control circuit board. When a problem due to dust, water, or the like occurs in the drive circuit board, the operation of the entire DC brushless motor is defective. For this reason, the drive circuit board is also required to be improved in dust resistance and waterproofness. For this purpose, resin coating or the like is usually performed on the drive circuit board. However, the resin coating process is a manual operation and causes a decrease in productivity.

  Therefore, a technical problem to be solved in order to improve dustproofness and waterproofness as well as productivity arises, and the present invention aims to solve this problem.

  The present invention has been proposed in order to achieve the above object, and the invention according to claim 1 is directed to a bracket member projecting from a motor body provided with a plurality of drive coils and a rotor. In a DC brushless motor in which a drive circuit board on which a drive circuit for switching current to a coil is mounted is integrally mounted, a board case having a shape and dimension corresponding to the drive circuit board is provided, and a required mounting mode for the bracket member DC brushless in which the drive circuit board in a combined state is inserted into the board case, and the drive circuit board is integrally attached to the bracket member by a potting material dropped and solidified in the board case Provide a motor.

  According to this configuration, when the drive circuit board is attached to the bracket member, the drive circuit board in a state of being combined with the bracket member so as to have a required attachment mode is inserted into the board case, and only the potting process is performed. Then, the drive circuit board is integrally attached to the bracket member in a required attachment manner, and the drive circuit board is coated with a thermosetting resin such as epoxy or silicone as a potting material.

  According to the first aspect of the present invention, when the drive circuit board is attached to the bracket member, only the potting process is performed, and the drive circuit board is efficiently and integrally attached to the bracket member without requiring a screwing process or the like. In addition to improving productivity, the driving circuit board is coated with a thermosetting resin, thereby improving the dust resistance and waterproofing.

The figure shows a DC brushless motor according to an embodiment of the present invention.
The longitudinal cross-sectional view which shows the internal structure of DC brushless motor. The perspective view which shows the external appearance of a substrate case part. The perspective view of DC brushless motor which removes and shows a substrate case.

  In order to achieve the object of improving dust resistance and waterproofness as well as productivity, the present invention provides a bracket member projecting from a motor body provided with a plurality of drive coils and a rotor to the plurality of drive coils. In a DC brushless motor integrally mounted with a drive circuit board on which a drive circuit for switching current is mounted, a board case having a shape and dimension corresponding to the drive circuit board is provided, and a required mounting mode is obtained with respect to the bracket member. The driving circuit board in such a combined state is inserted into the board case, and the driving circuit board is integrally attached to the bracket member by a potting material that is dropped and solidified in the board case.

  A preferred embodiment of the present invention will be described below with reference to FIGS. First, the configuration of the DC brushless motor according to the present embodiment will be described. As shown in FIGS. 1 and 3, a DC brushless motor 1 includes a stator 3 having a plurality of drive coils 2, and a magnet rotor 4 rotatably provided at an inner center portion of the stator 3. The main body 5 and the drive circuit board 7 integrally attached to the motor main body 5 through a plurality of bracket members 6 projecting from the motor main body 5 side are mainly configured.

  The stator 3 is configured by winding a drive coil 2 on a winding frame 9 made of an insulating material attached to each core 8 portion. The magnet rotor 4 is fixed to an output shaft 10, and the output shaft 10 is rotatably supported by ball bearings 11 and 11. The drive circuit board 7 has a portion corresponding to the output shaft 10 cut out into a circular shape 7a and formed in a ring shape. The drive circuit board 7 switches current to the plurality of drive coils 2,. The drive circuits 12,... Are mounted as ICs. A control signal line from a control circuit (not shown) for controlling the output torque and rotation speed of the DC brushless motor 1 and a power supply line from a battery (not shown) are connected to the terminal portion 7b of the drive circuit board 7.

  In this embodiment, as shown in FIG. 2, a board case 13 having a shape corresponding to the drive circuit board 7 is provided and combined with the bracket members 6,. The drive circuit board 7 is inserted into the board case 13, and the potting process is performed on the drive circuit board 7 and the bracket members 6,. At this time, temporary fixing may be performed by screws or snap fit so that the position of each component does not shift. By this potting process, a potting material (not shown) is dropped and solidified in the substrate case 13, and the drive circuit board 7 is integrally attached to the bracket members 6. A motor cooling fan 14 is attached to the portion of the output shaft 10 that protrudes to the back side of the motor body 5.

  Next, the operation of the DC brushless motor 1 configured as described above will be described. When the drive circuit board 7 is attached to the bracket members 6,..., The drive circuit board 7 combined with the bracket members 6,. The drive circuit board 7 is integrally attached to the bracket members 6,... In a required manner by dropping a potting material therein and performing a potting process. At the same time, the drive circuit board 7 is coated with a thermosetting resin such as epoxy or silicone which is a potting material.

  As described above, in the DC brushless motor 1 according to this embodiment, when the drive circuit board 7 is attached to the bracket members 6,... The drive circuit board 7 is efficiently and integrally attached to the bracket members 6,... In a required attachment manner to improve productivity, and the drive circuit board 7 is coated with a thermosetting resin so as to be dustproof and waterproof. Improves.

  The present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.

  The present invention can be applied to a rotational drive source in an electric power tool such as an impact driver, which is indispensable to improve dust resistance and waterproofness as well as productivity.

1 DC brushless motor 2 Drive coil 3 Stator 4 Magnet rotor (rotor)
DESCRIPTION OF SYMBOLS 5 Motor main body 6 Bracket member 7 Drive circuit board 8 Core 9 Winding frame 10 Output shaft 11 Ball bearing 12 Drive circuit 13 Board case 14 Fan

Claims (1)

In a DC brushless motor in which a drive circuit board in which a drive circuit for switching current to the plurality of drive coils is mounted integrally on a bracket member protruding from a motor main body side including a plurality of drive coils and a rotor ,
A board case having a shape and dimension corresponding to the drive circuit board is provided, and the drive circuit board in a state of being combined with the bracket member so as to have a required attachment mode is inserted into the board case, A DC brushless motor, wherein the drive circuit board is integrally attached to the bracket member by a potting material that is dropped and solidified on the bracket member.

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