JP2009000779A - Electric tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To securely improve an effect of cooling a motor rotation control electronic component such as FET in a handle grip even a battery is mounted to the handle grip. <P>SOLUTION: In an electric tool, a motor switch 7 and the FET 8 as the motor rotation control electronic component are stored in the handle grip 1b integrated with a housing 1a for storing a motor 2 mounted with a cooling fan 13. An inside of the handle grip 1b is partitioned by a bulkhead 18 continuing to the housing 1a for forming an independent ventilation passage 19 communicating with the cooling fan 13 inside the handle grip 1b. At least the FET 8 is provided in the ventilation passage 19. An intake port 17 communicating with the ventilation passage 19 is formed at the handle grip 1b. Fresh air taken from the intake port 17 by the cooling fan 13 is exhausted to the outside of the housing 1a through the ventilation passage 19. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power tool, and more particularly to a power tool capable of improving the cooling effect of motor rotation control electronic components such as FETs housed in a handle grip.

  An impact driver as an electric tool is disclosed in Japanese Patent Application Laid-Open No. 2005-74613. Hereinafter, this conventional electric tool will be described with reference to the drawings.

  6 is a cross-sectional front view showing a conventional electric tool, and FIG. 7 is a cross-sectional view taken along line AA of FIG.

  6 and 7, reference numeral 1 denotes an electric power tool main body, which is divided into two that can be coupled together, a motor 1 housed in the housing 1a, and a planetary gear unit 3 for reducing the rotation of the motor 2. And a spindle shaft 4 operated by the planetary gear unit 3 and a tool chuck 5 to which a bit (not shown) is fixed. When the motor 3 rotates, the rotation is decelerated by the planetary gear device 3, transmitted to the tool chuck 5 through the spindle shaft 4, and screw tightening or the like is performed by a bit.

  In the lower part of the housing 1a, a handle grip 1b that is divided into two so as to be connectable in the same manner as the housing 1a is provided integrally with the housing 1a. Housed in the handle grip 1b are a motor switch 7 having a trigger 6 for controlling ON / OFF of the motor 2, the number of rotations, and the like, and an FET 8 as a motor rotation control electronic component. The trigger 6 is provided near the base of the handle grip 1b. A coupling hole 10 for detachably connecting the battery 9 is formed in the lower portion of the handle grip 1b. The battery 9 is formed with a coupling protrusion 9a. By inserting the coupling protrusion 9a into the coupling hole 10, the battery 9 is coupled to the handle grip 1b and is electrically connected to the motor switch 7 at the same time. .

  The motor 2, the motor switch 7 and the FET 8 are connected by a lead wire 11. The FET 8 is attached to a heat dissipation block 12 for preventing this overheating. The heat dissipation block 12 is attached to the handle grip 1b so as to be exposed in the coupling hole 10, and forms a part of the wall surface of the coupling hole 10. Yes.

  According to the conventional electric tool described above, when the trigger 6 is operated and the motor switch 7 is turned on, the motor 2 is started, the spindle shaft 4 is rotated, and screwing or the like is performed by the bit. The heat of the FET 8 generated by the operation of the motor 2 is radiated from the surface of the coupling hole 10 after the battery 9 is extracted through the heat radiating block 12, thereby cooling the FET 8.

JP 2005-74613 A

  According to the conventional electric tool described above, the heat of the FET 8 generated by the operation of the motor 2 is radiated from the surface of the coupling hole 10 after the battery 9 is extracted through the heat radiating block 12, thereby cooling the FET 8. There were the following problems.

  When the battery 9 is attached to the handle grip 1b, the air in the handle grip 1b is not easily exhausted to the outside of the handle grip 1b, and a sufficient heat radiation effect cannot be obtained due to the heat generated by the battery 9.

  Accordingly, an object of the present invention is to provide an electric tool capable of reliably improving the cooling effect of motor rotation control electronic components such as FETs in the handle grip even when the battery is mounted on the handle grip. There is to do.

  The present invention has been made to achieve the above object, and is characterized by the following.

  According to the first aspect of the present invention, the motor switch (7) and the motor are provided in the handle grip (1b) integrated with the housing (1a) in which the motor (2) to which the cooling fan (13) is attached is housed. In the electric power tool in which the rotation control electronic component (8) is housed, the handle grip (1b) is partitioned by a partition wall (18) connected to the housing (1a), whereby the handle grip (1b) is An independent ventilation path (19) communicating with the cooling fan (13) is formed, and at least the motor rotation control electronic component (8) is disposed in the ventilation path (19), and the ventilation path is disposed in the handle grip (1b). An air inlet (17) leading to (19) is formed, and outside air sucked from the air inlet (17) by the cooling fan (13) passes through the air passage (19). Those having features to be evacuated to the housing (1a) outside Te.

  The invention according to claim 2 is characterized in that, in the invention according to claim 1, the intake port (17) is formed at a position where the handle grip (1b) is not blocked by a gripping hand. Is.

  The invention described in claim 3 is characterized in that, in the invention described in claim 1 or 2, the intake port (17) is formed in a lower part of the handle grip (1b).

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein a heat dissipation block (12) is attached to the motor rotation control electronic component, and the heat dissipation block (12) It is characterized by being positioned in the handle grip (1b) by (18).

  A battery is mounted on the handle grip by forming an air ventilation path dedicated to cooling at least the motor rotation control electronics in the handle grip and forcing outside air into the ventilation path by a cooling fan attached to the motor. Even in this case, it is possible to improve the cooling effect of the motor rotation control electronic components such as FETs in the handle grip. Further, by forming an intake port for sucking outside air in the ventilation path at the lower part of the handle grip, there is no possibility that the intake port is blocked by a hand even when the tool is being used. Furthermore, by providing a heat dissipation block for the motor rotation control electronic component in the handle grip, the heat dissipation effect of the motor rotation control electronic component is further improved.

  One embodiment of the power tool of the present invention will be described with reference to the drawings.

  1 is a cross-sectional front view showing a driver drill as an electric tool of the present invention, FIG. 2 is a view showing a state in which motor rotation control electronic components are attached to a heat dissipation block, and FIG. FIG. 4 is a front view showing the driver drill of the present invention with a battery mounted thereon, and FIG. 5 is a left side view showing the driver drill of the present invention mounted with a battery. For ease of explanation, FIGS. 1 and 4 are described with the right side as the front and the left side as the rear in the drawings.

  1 to 5, reference numeral 1 denotes an electric power tool main body, which is divided into two that can be coupled together, a motor 2 housed in the housing 1 a, and a planetary gear device 3 for reducing the rotation of the motor 2. A spindle shaft 4 that is operated by the planetary gear unit 3, a tool chuck 5 to which a bit (not shown) is fixed, and a torque adjusting cylinder 1c. The motor 2 is positioned by a motor holding wall 1d formed in the housing 1a. When the motor 2 rotates, the rotation is decelerated by the planetary gear device 3, transmitted to the tool chuck 5 via the spindle shaft 4, and screw tightening or the like is performed by a bit.

  A cooling fan 13 is attached to the rear portion of the motor 2, that is, to the motor rotation shaft opposite to the planetary gear device 3. As shown in FIG. 5, a motor main air inlet 14 is formed in the side surface of the housing 1a on the cooling fan 13 side, and as shown in FIG. 4, a motor auxiliary air inlet 15 is formed on the front and rear surfaces of the housing 1a. Then, as shown in FIG. 4, exhaust ports 16 are formed on both side surfaces of the housing 1a near the motor 2. As shown in FIG. The outside air sucked from the motor main air inlet 14 and the motor auxiliary air inlet 15 by the cooling fan 13 cools the motor 2 and is then exhausted out of the housing 1 a through the air outlet 16.

  A handle grip 1b is provided integrally with the lower portion of the housing 1a. The handle grip 1b is also divided into two so as to be coupled together with the housing 1a. An intake port 17 for sucking outside air mainly for cooling electronic components is formed at the lower part of the handlebar grip 1b and behind the lower end (left side in FIG. 1). Since the intake port 17 is formed at the lower part of the handlebar grip 1b and at the rear of the lower end, even if the handlebar grip 1b is gripped by hand when operating the tool, there is no possibility that the intake port 17 is blocked. The handlebar grip 1b is partitioned by a partition wall 18 connected from the lower end thereof to the motor holding wall 1d, whereby an independent ventilation path 19 communicating with the cooling fan 13 is formed in the handlebar grip 1b. The outside air sucked from the intake port 17 by the cooling fan 13 passes through the ventilation path 19 and cools the FET 8 and its heat radiation block 12 as motor rotation control electronic components to be described later, and then an opening formed in the motor holding wall 1d. 20 is exhausted out of the housing 1a through the exhaust port 16. Therefore, the outside air sucked from the air inlet 17 also acts for cooling the motor 2 and improves the cooling effect.

  Housed in the handle grip 1b are a motor switch 7 having a trigger 6 for controlling ON / OFF of the motor 2, the number of rotations, and the like, and an FET 8 as a motor rotation control electronic component. The trigger 6 is provided on the front surface (right side in FIG. 1) near the base of the handle grip 1b. Since the trigger 6 is provided outside the ventilation path 19, dust or the like is not sucked by the cooling fan 13 from the gap between the trigger 6 and the handle grip 1b together with the outside air. Can be prevented. The motor 2, the motor switch 7 and the FET 8 are connected by a lead wire 11. Since the lead wire 11 is arranged in the ventilation path 19 and is connected to the terminal of the motor switch 7, even if water or dust enters from the gap between the trigger 6 and the handle grip 1b, the lead wire 11 11 and the terminal side of the motor switch 7 are difficult to enter, and disconnection or the like can be prevented.

  A battery 9 can be attached to the lower part of the handle grip 1b, and the battery 9 and the motor switch 7 are electrically connected simultaneously with the attachment of the battery 9.

  As shown in FIGS. 2 and 3, a heat dissipation block 12 made of an aluminum alloy or the like is attached to the FET 8. The heat dissipating block 12 prevents overheating of the FET 8 that generates heat when the motor 2 is driven, and is fixed to the FET 8 by a set screw 21. The heat dissipating block 12 attached to the FET 8 is sandwiched between the partition walls 18 of the handle grip 1b made of a split piece, and the position is determined.

  Since the FET 8 and a part of the heat dissipation block 12 are arranged in the ventilation path 19, the FET 8 and the heat dissipation block 12 are reliably cooled by the outside air sucked from the intake port 17 by the cooling fan 13. The partition wall 18 may be formed so that all of the heat dissipation block 12 or only the FET 8 is disposed in the ventilation path 19.

  The above is a case where the present invention is applied to a driver drill, but it goes without saying that it can be applied to other electric tools such as an impact driver.

It is a section front view showing a driver drill as an electric tool of this invention. It is a figure which shows the state which attached the motor rotation control electronic component to the thermal radiation block. It is AA sectional drawing of FIG. It is a front view which shows the driver drill of this invention with which the battery was mounted | worn. It is a left view which shows the driver drill of this invention with which the battery was mounted | worn. It is a cross-sectional front view which shows the conventional electric tool. It is AA sectional drawing of FIG.

1: Electric tool body 1a: Housing 1b: Handle grip 1c: Torque adjustment cylinder 1d: Motor holding wall 2: Motor 3: Planetary gear unit 4: Spindle shaft 5: Tool chuck 6: Trigger 7: Switch for motor 8: FET
9: Battery 9a: Coupling protrusion 10: Coupling hole 11: Lead wire 12: Heat radiation block 13: Cooling fan 14: Motor main air inlet 15: Motor auxiliary air inlet 16: Air outlet 17: Air inlet 18: Bulkhead 19: Ventilation path 20: Opening 21: Set screw

Claims (4)

In a power tool in which a motor switch and a motor rotation control electronic component are housed in a handle grip integrated with a housing in which a motor to which a cooling fan is attached is housed,
By partitioning the inside of the handle grip with a partition wall connected to the housing, an independent ventilation path leading to the cooling fan is formed in the handle grip, and at least the motor rotation control electronic component is disposed in the ventilation path, An electric power tool characterized in that an intake port communicating with the ventilation path is formed in a handle grip, and outside air sucked from the intake port by the cooling fan is exhausted out of the housing through the ventilation path.   The power tool according to claim 1, wherein the intake port is formed at a position that is not blocked by a gripping hand in the handle grip.   The power tool according to claim 1, wherein the intake port is formed in a lower part of the handle grip.   The electric motor according to any one of claims 1 to 3, wherein a heat radiating block is attached to the motor rotation control electronic component, and the heat radiating block is positioned in the handle grip by the partition wall. tool.

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