JP2018187699A - Electric tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric tool which achieves excellent cooling performance of a battery pack.SOLUTION: A portable cutter 1 includes: a motor 40; a body housing 20 which houses the motor 40; a fan 45 which is rotated by the motor 40; and a battery pack 50 disposed at the lateral side of a motor housing 30 of the body housing 20. An air channel CA1 connecting a ventilator window 31a of the motor housing 30 with the fan 45 and an air channel CA2 connecting a ventilator window 51a of the battery pack 50 with the fan 45 are formed by rotation of the fan 45.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power tool having a configuration in which a battery pack can be detachably attached to a power tool body.

  2. Description of the Related Art Generally, an electric tool is known in which a battery pack is detachable from an electric tool main body incorporating an electric motor, and the battery pack is attached during use. Since the battery cell built in the battery pack generates heat due to its internal resistance, the temperature of the battery cell greatly increases when the load is high.

JP, 2006-179536, A

  When the temperature of the battery cell exceeds a predetermined threshold, it is necessary to stop the power supply from the battery pack until the temperature of the battery cell decreases in order to protect the battery cell. From the viewpoint of improving work efficiency, it is preferable that the operation of such a protection function is small.

  The present invention has been made in view of such a situation, and an object thereof is to provide an electric tool having excellent battery pack cooling performance.

One embodiment of the present invention is a power tool. This electric tool
A motor,
A housing for housing the motor;
A fan rotated by the motor;
A battery pack disposed on the side of the motor housing portion of the housing and supplying power to the motor;
A first wind window provided in the housing;
A second wind window for cooling the battery pack,
A rotation of the fan forms a first cooling air passage connecting the first air window and the fan, and a second cooling air passage connecting the second air window and the fan. And

  The second wind window may be provided in the battery pack.

  The second air window may be an exhaust port provided in the housing.

  In the second cooling air passage, cooling air may flow from the battery pack toward the fan.

  In the second cooling air passage, cooling air may flow from the fan toward the battery pack.

  It should be noted that any combination of the above-described constituent elements, and those obtained by converting the expression of the present invention between methods and systems are also effective as aspects of the present invention.

  According to the electric tool of the present invention, it is possible to provide an electric tool that is excellent in the cooling performance of the battery pack.

1 is a cross-sectional plan view of a power tool 1 according to Embodiment 1 of the present invention. II-II sectional drawing of FIG. The perspective view of the battery pack 50 attached to the electric tool 1 so that attachment or detachment is possible. The plane sectional view of electric tool 2 concerning Embodiment 2 of the present invention. VV sectional drawing of FIG. The plane sectional view of electric tool 3 concerning Embodiment 3 of the present invention. VII-VII sectional drawing of FIG. The left view of the electric tool 4 which concerns on Embodiment 4 of this invention. The right view of the electric tool 4. FIG. Sectional drawing which shows the inside of the motor housing 30 and the battery pack 50 of FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or equivalent component, member, etc. which are shown by each drawing, and the overlapping description is abbreviate | omitted suitably. In addition, the embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

Embodiment 1
FIG. 1 is a plan sectional view of a power tool 1 according to Embodiment 1 of the present invention. 2 is a cross-sectional view taken along the line II-II in FIG. 1 and 2, the front / rear, top / bottom and left / right directions of the power tool 1 are defined. FIG. 3 is a perspective view of the battery pack 50 that is detachably attached to the electric tool 1. The battery pack 50 is attached to and detached from the main body housing 20 so as to slide in the front-rear direction. The electric tool 1 is a cordless portable cutting machine (portable circular saw), and operates with power supplied from a battery pack 50 that is detachably mounted. The electric power tool 1 includes a base 10 and a main body housing 20 attached to the base 10. The base 10 is a substantially rectangular plate made of metal such as aluminum. The longitudinal direction of the base 10 coincides with the cutting direction. The bottom surface of the base 10 is a sliding surface with the work material. The main body housing 20 is connected to the base 10 at two positions on the front and rear sides, is rotatable with respect to the base 10 in the vertical direction, and can be tilted to at least one of the left and right sides.

  The main body housing 20 includes a handle housing 25, a gear cover 28, and a motor housing (motor housing portion) 30. The motor housing 30 is, for example, a resin molded body, and houses a motor (brushless motor) 40 and an inverter circuit board 33. The inverter circuit board 33 is located on the left side of the motor 40 and has a plurality of switching elements 34 such as FETs and IGBTs mounted thereon. The handle housing 25 is, for example, a resin molded body, and has a grip portion 25a as shown in FIG. The grip portion 25a is provided with a trigger switch 25b for the user to switch between driving and stopping of the motor 40.

  The battery pack 50 is slidably mounted on the handle housing 25 at a position on the side (rear) of the motor housing 30 from the rear toward the front (approaching the motor housing 30). Here, the side of the motor housing 30 means the outside of the motor housing 30 in the radial direction of the motor 40 (direction perpendicular to the output shaft). The motor housing 30 and the battery pack 50 are adjacent to each other (located in the vicinity). The handle housing 25 accommodates the control circuit board 23 at a position on the right side of the attached battery pack 50. The control circuit board 23 is equipped with a controller that controls driving of the motor 40 by on / off control (for example, PWM control) of the switching element 34. When the trigger switch 25b is turned on, the motor 40 is driven under the control of the controller. The rotation of the motor 40 is decelerated by the reduction mechanism and transmitted to the circular saw blade 21.

  Hereinafter, the cooling structure in the electric power tool 1 will be described. A fan 45 is coaxially provided on the right side of the motor 40. The fan 45 is a centrifugal fan. The motor 40 side of the outer peripheral portion of the fan 45 faces the fan guide portion 32 of the motor housing 30. The motor housing 30 has wind windows 31a and 31b. The wind window 31 a as the first wind window is an intake port and is provided on the left side of the motor 40. The wind window 31 b is an exhaust port and is provided at a position facing the right end of the motor 40 on the left side of the fan guide portion 32 and facing the battery pack 50.

  An air path guide portion 27 of the handle housing 25 extends between the motor housing 30 and the battery pack 50. The air passage guide portion 27 includes air windows 27a and 27b. The wind window 27a is close to the wind window 31b of the motor housing 30 and communicates with the wind window 31b. The wind window 27b is close to the wind window 51b of the battery pack 50 and communicates with the wind window 51b. The air guide 27 is formed integrally with the handle housing 25 from the viewpoint of cost and assemblability. However, the air guide 27 is formed as an independent part made of an elastic body such as rubber and is configured to be in pressure contact with the battery pack 50. The external leakage of the cooling air may be suppressed.

  The battery pack 50 has a plurality of battery cells 52 housed inside a battery housing 51, and the battery housing 51 is provided with wind windows 51 a and 51 b. Specifically, ten battery cells 52 are provided in the battery pack 50 such that five battery cells 52 arranged in the front-rear direction are arranged vertically so that the longitudinal direction is along the left-right direction. The wind windows 51a and 51b exist in the past in order to pass the air flow generated by the fan of the charger into the battery housing 51 when the battery pack 50 is connected to a charger (not shown) for charging. . The wind window 51 a is a second wind window, functions as an air inlet, and is provided on the rear upper surface of the battery housing 51. The wind window 51 b functions as an exhaust port and is provided on the front surface of the battery housing 51. The space occupied by the battery cells 52 is long in the front-rear direction. By providing the wind window 51a and the wind window 51b in the front and rear of the battery pack 50, most of the battery cells 52 can be included on the cooling air passage connecting the wind window 51a and the wind window 51b. The battery cell 52 can be effectively cooled even with a small number of wind windows.

  The handle housing 25 has wind windows 25c and 25d. The wind window 25 c is provided at the rear end of the handle housing 25. The air window 25d is adjacent to the air window 51a of the battery pack 50 and communicates with the air window 51a.

  By the rotation of the fan 45, an air path CA1 as a first cooling air path and an air path CA2 as a second cooling air path are formed. The air passage CA1 enters the motor housing 30 through the air window 31a, passes through or near the motor 40, cools the motor 40, passes through the inside of the fan guide portion 32, and reaches the fan 45. The air path CA2 enters the inside of the battery housing 51 through the wind windows 25c, 25d, 51a, cools the battery cells 52 through the vicinity of the battery cells 52, and is discharged to the outside of the battery housing 51 through the wind windows 51b. Then, the air enters the motor housing 30 through the air windows 27b, 27a, 31b, merges with the air passage CA1, and reaches the fan 45 through the inside of the fan guide portion 32.

  According to the present embodiment, the following effects can be mainly achieved.

(1) Since the battery pack 50 is also cooled using the fan 45 for cooling the motor, the battery pack 50 can be cooled while suppressing the number of components, and the work efficiency is deteriorated due to the protection function of the battery pack 50 being activated. Can be suppressed.

(2) Since the cooling air taken into the battery pack 50 is fresh cooling air that does not cool other components such as the motor 40, the cooling efficiency of the battery pack 50 is high.

(3) Since the upward air window 51a of the battery pack 50 takes in air through the main body housing 20 (through the air windows 25c and 25d), the upward air window 51a on the battery pack 50 side is not exposed to the outside air, and dust is contained in the battery pack 50. Is difficult to flow in.

(4) Since the wind windows 51a and 51b of the battery pack 50 are conventionally used for charging, it is not necessary to change the shape of the battery housing 51 for cooling the battery pack 50 by the fan 45. In addition, since the battery pack 50 is disposed adjacent to the motor housing 20 (aligned in the front-rear direction), the air window provided in the battery pack 50 and the cooling air passage formed in the motor housing 20 can be easily communicated with each other.

(5) In order to effectively cool the battery cells 52 arranged in the front-rear direction, the battery pack 50 provided with wind windows in the front-rear direction is slid in the front-rear direction with respect to the main body housing 20, so The wind window 51b of the provided battery pack 50 can be positioned in the vicinity of the cooling air flowing in the motor housing 30 and the fan 45, and the cooling air path connecting the fan 45 and the air window 51b can be shortened, so that the air path is formed. Therefore, the main body housing 20 can be downsized.

Embodiment 2
FIG. 4 is a cross-sectional plan view of the electric power tool 2 according to Embodiment 2 of the present invention. 5 is a cross-sectional view taken along the line VV in FIG. In the electric power tool 2 of the present embodiment, the wind window 31b is eliminated and the air path CA2 is replaced with the air path CA3, as compared with that of the first embodiment. In the present embodiment, the wind window 51b of the battery pack 50 functions as an intake port, and the wind window 51a functions as an exhaust port. The air passage CA3 passes through the air passage guide portion 27 from the fan 45, enters the inside of the battery housing 51 through the air windows 27b and 51b, cools the battery cell 52 through the vicinity of the battery cell 52, and passes the air window 51a. It is discharged to the outside of the battery housing 51, and is discharged to the outside of the handle housing 25 through the wind windows 25 d and 25 c. Other points of the present embodiment are the same as those of the first embodiment. According to the present embodiment, since the cooling air taken into battery pack 50 becomes the cooling air after cooling motor 40, the cooling performance of battery pack 50 is reduced as compared with the first embodiment. Since the air volume for cooling the motor 40 increases, the cooling performance of the motor 40 is high.

Embodiment 3
FIG. 6 is a plan sectional view of the electric power tool 3 according to Embodiment 3 of the present invention. 7 is a sectional view taken along line VII-VII in FIG. In the present embodiment, as compared with the second embodiment, the battery pack 50 does not have the wind windows 51a and 51b, and the air path CA3 is replaced with the air path CA4. The air path CA4 passes from the fan 45 through the air window 27c (second air window) and passes in the vicinity of the front surface and the right side surface of the battery housing 51. Other points of the present embodiment are the same as those of the second embodiment. According to the present embodiment, since the air path CA4 does not pass through the inside of the battery pack 50, the cooling performance of the battery pack 50 is lowered, but since it is close to the main body housing 20, the front surface of the battery housing 51 and A constant cooling performance can be secured by flowing cooling air in the vicinity of the right side surface.

Embodiment 4
FIG. 8 is a left side view of the power tool 4 according to Embodiment 4 of the present invention. FIG. 9 is a right side view of the power tool 4. 10 is a cross-sectional view taken along the line XX of FIG. The electric tool 4 is a cordless tabletop cutting machine (tabletop circular saw), and operates with power supplied from a battery pack 50 that is detachably mounted. The electric power tool 4 includes a base 81, a turntable 82, a holder 85, a guide bar 87, a support member 88, and a cutting part 92. The base 81 is a placement unit on a floor surface or the like. The turntable 82 is rotatably connected to the base 81. The holder 85 is erected near the rear end portion of the turntable 82 and can tilt with respect to the turntable 82. Near the upper end of the holder 85, two guide bars 87 are supported. A support member 88 is slidably supported on the guide bar 87. The main body housing 92 is supported by the support member 88 so as to be swingable up and down. The main body housing 92 is detachable from the battery pack 50 and supports a circular saw blade (not shown).

  In the present embodiment, the air passage CA1 shown in FIG. 10 enters the motor housing 30 from the air window 31a (FIG. 9) of the motor housing 30 and merges with the air passage CA5 described later, and the inside or the vicinity of the motor 40. The motor 40 is cooled by passing through the fan guide portion 32 and reaches the fan 45. The air passage CA5 as the second cooling air passage enters the inside of the battery pack 50 from the air window 51a of the battery pack 50 via the air windows 92a and 92b of the battery pack mounting portion of the main body housing 92, and enters the inside of the battery housing 51. The battery cell 52 is cooled through the vicinity of the battery cell 52, enters the inside of the motor housing 30 through the wind window 51b and the wind window 31c of the motor housing 30 communicating with the wind window 51b, and merges with the air path CA1. The fan 45 is an axial fan in the present embodiment.

  The present invention has been described above by taking the embodiment as an example. However, it is understood by those skilled in the art that various modifications can be made to each component and each processing process of the embodiment within the scope of the claims. By the way. Hereinafter, modifications will be described.

  The present invention is not limited to a portable cutting machine or a tabletop cutting machine, and can be applied to all electric tools including a battery pack disposed on the side of a motor housing portion.

1-4 Power tool, 10 base, 20 body housing, 25 handle housing, 25a grip part, 25b trigger switch, 27 air path guide part, 27a, 27b wind window, 28 gear cover, 30 motor housing (motor housing part), 31a wind window (Intake port), 31b wind window (exhaust port), 32 fan guide part, 33 inverter circuit board, 40 motor (brushless motor), 50 battery pack, 51 battery housing, 51a, 51b wind window, 52 battery cell, 81 base, 82 Turntable, 85 holder, 87 guide bar, 88 support member, 92 cutting part

Claims (5)

A motor,
A housing for housing the motor;
A fan rotated by the motor;
A battery pack disposed on the side of the motor housing portion of the housing and supplying power to the motor;
A first wind window provided in the housing;
A second wind window for cooling the battery pack,
A rotation of the fan forms a first cooling air passage connecting the first air window and the fan, and a second cooling air passage connecting the second air window and the fan. A power tool.   The power tool according to claim 1, wherein the second wind window is provided in the battery pack.   The power tool according to claim 1, wherein the second wind window is an exhaust port provided in the housing.   The power tool according to claim 2, wherein in the second cooling air passage, cooling air flows from the battery pack toward the fan.   4. The electric tool according to claim 2, wherein cooling air flows from the fan toward the battery pack in the second cooling air passage. 5.

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