Power tool

Abstract

The present invention provides a power tool that suppresses a reduction in workability. The power tool includes: a motor; a fan; a main body portion that extends in the front-rear direction and houses the motor and the fan; a grip portion that extends downward from the main body portion; a connecting portion that is disposed more forward than the grip portion and extends downward from the main body portion; a battery holding portion that is connected to the lower end portion of the grip portion and the lower end portion of the connecting portion; and an inverter circuit board that switches the current supplied from the battery held in the battery holding portion to the motor. The inverter circuit board is housed in the main body portion.

Description

Technical Field

[0001] The present invention relates to a power tool. Background Art

[0002] In the technical field of power tools, a power tool including a motor and a controller is known as disclosed in Patent Document 1.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2017 - 100259 Summary of the Invention

[0006] The motor is driven based on a control signal output from the controller. If a high current flows through the controller, the temperature of the controller may rise. If the temperature of the controller rises, it is necessary to reduce or stop the output of the motor for heat dissipation of the controller. As a result, the workability of using the power tool is reduced.

[0007] An object of the present invention is to suppress a reduction in workability.

[0008] According to the present invention, there is provided a power tool including: a motor; a fan; a main body portion that extends in the front - rear direction and houses the motor and the fan; a grip portion that extends downward from the main body portion; a connecting portion that is disposed more forward than the grip portion and extends downward from the main body portion; a battery holding portion that is connected to the lower end portion of the grip portion and the lower end portion of the connecting portion; and an inverter circuit board that switches the current supplied from a battery held in the battery holding portion to the motor, the inverter circuit board being housed in the main body portion.

[0009] According to the present invention, a reduction in workability can be suppressed. Brief Description of the Drawings

[0010] Figure 1 It is a perspective view showing a power tool according to an embodiment.

[0011] Figure 2 It is a cross - sectional view showing a power tool according to an embodiment.

[0012] Figure 3 It is a block diagram showing a power tool according to an embodiment.

[0013] Figure 4 It is a diagram for explaining a wiring structure of a power tool according to an embodiment.

[0014] Figure 5This is a diagram for explaining the wiring structure of the power tool involved in the embodiment.

[0015] Explanation of Reference Numerals

[0016] 1A... Power tool, 1B... Power tool, 2... Housing, 2L... Left housing, 2R... Right housing, 2S... Screw, 3... Gearbox, 4... Motor, 5... Fan, 6... Power transmission mechanism, 7... Output part, 8... Inverter circuit board, 8C... Housing, 9... Sensor board, 10... Control circuit board, 10C... Housing, 11... Trigger switch, 11A... Trigger part, 11B... Switch body, 12... Forward and reverse switching lever, 13... Speed switching lever, 14... Mode conversion ring, 15... Clutch dial, 16... Interface panel, 17... Lamp, 18A... Air inlet, 18B... Exhaust port, 19... Battery assembly part, 20... Battery, 20A... Release button, 21... Main body part, 21L... Rib, 22... Gripping part, 23... Connecting part, 24... Battery holding part, 24L... Rib, 41... Stator, 41A... Stator core, 41B... Front insulator, 41C... Rear insulator, 41D... Coil, 41E... Connecting component, 42... Rotor, 42A... Rotor shaft, 42B... Rotor core, 42C... Permanent magnet, 43... Bearing, 44... Bearing, 60... Pinion, 71... Spindle, 72... Chuck, 73... Bearing, 81... Inverter circuit, 82... Temperature detection circuit, 91... Magnetic sensor, 100... Microcomputer, 101... Control signal output circuit, 102... Rotor position detection circuit, 103... Step-down circuit, 104... Control system power supply circuit, 105... Battery voltage detection circuit, 106... Over-discharge detection circuit, 107... Current detection circuit, 108... Acceleration detection circuit, 109... Battery remaining amount display circuit, 201... First signal line, 202... Second signal line, 203... Third signal line, 204... Wire, 205... Wire, 206... Wire, 207... Fourth signal line, 301... Battery side terminal, 302... Tool side terminal, 810... Controller board, 810C... Housing, AX... Rotation axis, VL... Imaginary line. Detailed Embodiment

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments. The constituent elements of the embodiments described below can be appropriately combined. In addition, sometimes some constituent elements are not used.

[0018] In the embodiment, the terms left, right, front, rear, top, and bottom are used to describe the positional relationship of each part. These terms represent the relative position or direction with respect to the center of the power tool.

[0019] In an embodiment, the power tool is a vibration-driven drill having a motor. In the embodiment, the direction parallel to the rotation axis AX of the motor is appropriately referred to as the axial direction, the radial direction of the rotation axis AX of the motor is appropriately referred to as the radial direction, and the direction around the rotation axis AX of the motor is appropriately referred to as the circumferential direction or the rotation direction. Further, in the radial direction, the position close to the rotation axis AX of the motor or the direction approaching the rotation axis AX of the motor is appropriately referred to as the radially inner side, and the position away from the rotation axis AX of the motor or the direction departing from the rotation axis AX of the motor is appropriately referred to as the radially outer side. In the embodiment, the axial direction coincides with the front-rear direction.

[0020] [Overview of Power Tool]

[0021] Figure 1 FIG. is a perspective view showing a power tool 1A according to an embodiment. Figure 2 FIG. is a cross-sectional view showing a power tool 1A according to an embodiment.

[0022] As Figure 1 and Figure 2 shown, the power tool 1A includes: a housing 2, a gearbox 3, a motor 4, a fan 5, a power transmission mechanism 6, an output unit 7, an inverter circuit board 8, a sensor board 9, a control circuit board 10, a trigger switch 11, a forward / reverse switching lever 12, a speed switching lever 13, a mode conversion ring 14, a clutch dial 15, an interface panel 16, and a lamp 17.

[0023] The housing 2 is formed of synthetic resin. The housing 2 is composed of a pair of half-split housings. The housing 2 includes: a left housing 2L and a right housing 2R disposed to the right of the left housing 2L. The left housing 2L and the right housing 2R are fixed by a plurality of screws 2S.

[0024] The housing 2 has: a main body portion 21 that extends in the front-rear direction; a grip portion 22 that extends downward from the main body portion 21; a connecting portion 23 that is disposed more forward than the grip portion 22 and extends downward from the main body portion 21; and a battery holding portion 24 that is connected to the lower end portion of the grip portion 22 and the lower end portion of the connecting portion 23.

[0025] The main body portion 21 houses the motor 4 and the fan 5. The motor 4 and the fan 5 are disposed in the internal space of the main body portion 21. The main body portion 21 is integral with the grip portion 22 and the connecting portion 23.

[0026] The main body portion 21 has an air inlet 18A and an air outlet 18B. The air inlet 18A and the air outlet 18B are ventilation openings that connect the internal space of the main body portion 21 and the external space respectively. The air outlet 18B is provided more forward than the air inlet 18A. The air inlet 18A is provided on the left and right portions of the main body portion 21 respectively. The air outlet 18B is provided on the left and right portions of the main body portion 21 respectively. By the rotation of the fan 5, the air in the external space of the main body portion 21 flows into the internal space of the main body portion 21 through the air inlet 18A. By the rotation of the fan 5, the air in the internal space of the main body portion 21 flows out to the external space of the main body portion 21 through the air outlet 18B. That is, the air flowing into the internal space from the external space of the main body portion 21 flows through the air inlet 18A. The air flowing out from the internal space to the external space of the main body portion 21 flows through the air outlet 18B.

[0027] The gripping portion 22 is gripped by an operator. The gripping portion 22 protrudes downward from the lower portion of the main body portion 21. The gripping portion 22 has an internal space. The internal space of the main body portion 21 and the internal space of the gripping portion 22 are connected.

[0028] The connecting portion 23 is arranged more forward than the gripping portion 22. The connecting portion 23 protrudes downward from the lower portion of the main body portion 21. The connecting portion 23 has an internal space. The internal space of the main body portion 21 and the internal space of the connecting portion 23 are connected.

[0029] The battery holding portion 24 holds the battery 20 by means of the battery mounting portion 19. The battery holding portion 24 is connected to the lower end portion of the gripping portion 22 and the lower end portion of the connecting portion 23. The battery holding portion 24 has an internal space. The internal space of the battery holding portion 24, the internal space of the gripping portion 22, and the internal space of the connecting portion 23 are connected.

[0030] The battery mounting portion 19 is provided at the lower portion of the battery holding portion 24. The battery 20 is mounted on the battery mounting portion 19. The battery 20 can be loaded and unloaded from the battery mounting portion 19. By being mounted on the battery mounting portion 19, the battery 20 can supply power to the power tool 1A.

[0031] The battery 20 includes a secondary battery. In the embodiment, the battery 20 includes a rechargeable lithium-ion battery. The battery 20 has a release button 20A. The release button 20A is operated to release the fixation between the battery mounting portion 19 and the battery 20. The release button 20A is provided on the front surface of the battery 20.

[0032] The battery 20 has a battery-side terminal 301. The battery mounting portion 19 has a tool-side terminal 302. By mounting the battery 20 on the battery mounting portion 19 and connecting the battery-side terminal 301 and the tool-side terminal 302, power is supplied from the battery 20 to the power tool 1A.

[0033] The gearbox 3 is disposed in front of the main body 21. The gearbox 3 is formed of a metal such as aluminum. The front end portion of the main body 21 and the rear end portion of the gearbox 3 are connected. The gearbox 3 is cylindrical. The gearbox 3 houses a power transmission mechanism 6 including a plurality of gears.

[0034] The motor 4 generates power for driving the output portion 7. The motor 4 is housed in the main body 21. The motor 4 is driven based on the electric power supplied from the storage battery 20. The rotation shaft AX of the motor 4 extends in the front-rear direction.

[0035] The motor 4 is an in-rotor type DC brushless motor. The motor 4 has: a cylindrical stator 41, and a rotor 42 disposed inside the stator 41.

[0036] The stator 41 has: a stator core 41A including a plurality of steel plates laminated together; a front insulator 41B disposed at the front portion of the stator core 41A; a rear insulator 41C disposed at the rear portion of the stator core 41A; a plurality of coils 41D wound around the stator core 41A by means of the front insulator 41B and the rear insulator 41C; and a connecting member 41E supported by the front insulator 41C. The connecting member 41E connects the plurality of coils 41D.

[0037] The rotor 42 has: a rotor shaft 42A; a cylindrical rotor core 42B disposed around the rotor shaft 42A; and a plurality of permanent magnets 42C held by the rotor core 42B. The front portion of the rotor shaft 42A is rotatably supported by a bearing 43. The rear portion of the rotor shaft 42A is rotatably supported by a bearing 44.

[0038] The fan 5 is rotated to generate an air flow. The fan 5 is housed in the main body 21. The fan 5 is disposed more forward than the stator core 41A. The fan 5 is mounted on the rotor shaft 42A between the stator core 41A and the bearing 43. The exhaust port 18B is disposed around the fan 5.

[0039] A pinion 60 is provided at the front end portion of the rotor shaft 42A. The rotor shaft 42A is connected to the power transmission mechanism 6 by means of the pinion 60.

[0040] The power transmission mechanism 6 transmits the rotational force generated by the motor 4 to the output portion 7. The output portion 7 is driven based on the rotational force transmitted from the motor 4 via the power transmission mechanism 6. The power transmission mechanism 6 has: a speed reduction mechanism, a vibration mechanism, and a clutch mechanism. The speed reduction mechanism reduces the rotation of the rotor shaft 42A and rotates the output portion 7 at a rotational speed lower than that of the rotor shaft 42A. The speed reduction mechanism includes a planetary gear mechanism.

[0041] The output unit 7 is driven by the rotational force of the motor 4 transmitted via the power transmission mechanism 6. At least a part of the output unit 7 protrudes forward from the gearbox 3. A front-end tool is mounted on the output unit 7. The output unit 7 rotates with the front-end tool mounted thereon.

[0042] The output unit 7 includes: a main shaft 71, and a chuck 72 capable of holding the front-end tool.

[0043] The main shaft 71 is rotatably supported by the gearbox 3 via a bearing 73. The main shaft 71 can move in the front-rear direction while being supported by the bearing 73.

[0044] The chuck 72 can hold the front-end tool. The chuck 72 is connected to the front portion of the main shaft 71. The chuck 72 rotates by the rotation of the main shaft 71. The chuck 72 rotates while holding the front-end tool.

[0045] The inverter circuit board 8 switches the current supplied from the storage battery 20 held by the storage battery holding portion 24 to the motor 4. The inverter circuit board 8 is housed in the main body portion 21. The inverter circuit board 8 is housed in a housing 8C. The housing 8C is held by a rib 21L of the main body portion 21. The inverter circuit board 8 includes a plurality of switching elements. The inverter circuit board 8 is arranged in the internal space of the main body portion 21 below the motor 4. The inverter circuit board 8 is arranged behind the fan 5. In the front-rear direction, at least a part of the inverter circuit board 8 is arranged between the fan 5 and the air inlet 18A. In the front-rear direction, the fan 5 is arranged more forward than the center of the inverter circuit board 8, and the air inlet 18A is arranged more rearward than the center of the inverter circuit board 8.

[0046] By the rotation of the rotor shaft 42A, the fan 5 rotates, and thus the air in the external space of the housing 2 flows into the internal space of the main body portion 21 via the air inlet 18A. The air flowing into the internal space of the main body portion 21 contacts the motor 4 and the inverter circuit board 8 to cool the motor 4 and the inverter circuit board 8. The air that has contacted the motor 4 and the inverter circuit board 8 is discharged to the external space of the housing 2 via the air outlet 18B.

[0047] The sensor board 9 detects the rotation of the motor 4. The sensor board 9 is housed in the main body portion 21. The sensor board 9 is supported by a rear insulator 41C. The sensor board 9 includes a plurality of magnetic sensors. The sensor board 9 is arranged behind the stator core 41A. The detection signal of the sensor board 9 is output to the control circuit board 10.

[0048] The control circuit board 10 outputs a control signal for controlling the power tool 1A. The control circuit board 10 includes a microcomputer. The control circuit board 10 is housed in the battery holding portion 24. The control circuit board 10 is housed in the housing 10C. The housing 10C is held by the rib 24L of the battery holding portion 24. The control circuit board 10 can output a control signal for controlling the switching elements of the inverter circuit board 8. The control circuit board 10 is housed in the battery holding portion 24.

[0049] The trigger switch 11 is provided on the grip portion 22. The trigger switch 11 is operated to drive the motor 4. The trigger switch 11 includes a trigger member 11A and a switch body 11B. The trigger member 11A protrudes forward from the upper part of the front portion of the grip portion 22. The trigger member 11A is operated by the operator. The operator can operate the trigger member 11A with a finger while holding the grip portion 22 with one hand on the left or right. The switch body 11B is housed in the grip portion 22. By operating the trigger member 11A, the switch body 11B outputs an operation signal. The operation signal of the trigger switch 11 is output to the control circuit board 10.

[0050] Based on the operation signal from the trigger switch 11, the control circuit board 10 outputs a control signal for controlling the inverter circuit board 8 so that power is supplied from the battery 20 to the motor 4. By supplying power from the battery 20 to the motor 4, the motor 4 is driven.

[0051] The forward / reverse switching lever 12 is provided on the upper part of the side portion of the grip portion 22. The forward / reverse switching lever 12 is operated by the operator. By operating the forward / reverse switching lever 12, the rotation direction of the motor 4 is switched. The operator operates the forward / reverse switching lever 12 so that the rotation direction of the motor 4 is switched from one of the forward rotation direction and the reverse rotation direction to the other. By switching the rotation direction of the motor 4, the rotation direction of the output portion 7 can be switched.

[0052] The speed switching lever 13 is provided on the upper part of the main body portion 21. The speed switching lever 13 is operated by the operator. By operating the speed switching lever 13, the rotation speed of the output portion 7 is switched. The operator operates the speed switching lever 13 to be able to switch the rotation speed of the output portion 7 between a first speed and a second speed higher than the first speed.

[0053] The mode conversion ring 14 is arranged in front of the gearbox 3. The mode conversion ring 14 is operated by the operator. By operating the mode conversion ring 14, the operation mode of the power tool 1A is switched.

[0054] The operating modes of the power tool 1A include: a vibration mode in which the output unit 7 vibrates in the front-rear direction, and a non-vibration mode in which the output unit 7 does not vibrate in the front-rear direction. The non-vibration mode includes: a drilling mode in which power is transmitted to the output unit 7 regardless of the rotational load acting on the output unit 7; and a clutch mode in which the power transmitted to the output unit 7 is cut off based on the rotational load acting on the output unit 7.

[0055] The clutch dial 15 is disposed at the front part of the lower portion of the connecting portion 23. The clutch dial 15 is operated by the operator. The operation signal of the clutch dial 15 is output to the control circuit board 10. In the clutch mode, by operating the clutch dial 15, the current value for stopping the motor 4 is set. The current value is a value related to the rotational load acting on the output unit 7. When the rotational load acting on the output unit 7 reaches the value corresponding to the set current value, the motor 4 is stopped. By stopping the motor 4, the rotation of the output unit 7 is stopped.

[0056] The control circuit board 10 sets the current value for stopping the motor 4 based on the operation signal from the clutch dial 15. The control circuit board 10 detects the current value flowing through the motor 4 according to the voltage across the resistor Rs described later, and when it is determined that the detected current value has reached the set current value, the motor 4 is stopped.

[0057] The interface panel 16 is provided on the battery holding portion 24. The interface panel 16 is plate-shaped. The interface panel 16 includes a display device and an operation device. If the clutch dial 15 is operated, the set current value is displayed on the display device of the interface panel 16.

[0058] The interface panel 16 is disposed on the upper surface of the battery holding portion 24. In the front-rear direction, the interface panel 16 is disposed between the grip portion 22 and the connecting portion 23. That is, the interface panel 16 is disposed inside the space surrounded by the grip portion 22, the connecting portion 23, and the battery holding portion 24.

[0059] The lamp 17 is provided at the upper part of the front portion of the grip portion 22. The lamp 17 emits illumination light for illuminating the front of the power tool 1A. The lamp 17 includes, for example, a light emitting diode (LED: Light Emitting Diode).

[0060] [Control System]

[0061] Figure 3 is a block diagram showing the power tool 1A according to the embodiment. As Figure 3 shown, the power tool 1A includes: a motor 4, an inverter circuit board 8, a sensor board 9, a control circuit board 10, a trigger switch 11, and a battery 20.

[0062] The inverter circuit board 8 includes an inverter circuit 81 and a temperature detection circuit 82.

[0063] The inverter circuit 81 includes a plurality of switching elements. The plurality of switching elements switch the current supplied from the storage battery 20 to the coil 41D of the motor 4.

[0064] The temperature detection circuit 82 detects the temperature of the switching elements constituting the inverter circuit 81. The temperature detection circuit 82 sends a detection signal of the temperature of the switching elements to the microcomputer 100.

[0065] The sensor board 9 has a magnetic sensor 91. The magnetic sensor 91 detects the rotation of the rotor 42 by detecting the permanent magnet 42C of the rotor 42. The detection signal of the magnetic sensor 91 is sent to the microcomputer 100.

[0066] The control circuit board 10 includes a microcomputer 100 as a control unit, a control signal output circuit 101, a rotor position detection circuit 102, a step-down circuit 103, a control system power supply circuit 104, a battery voltage detection circuit 105, an over-discharge detection circuit 106, a current detection circuit 107, and an acceleration detection circuit 108.

[0067] The acceleration detection circuit 108 is provided to detect a sudden movement of the power tool 1A. When the output unit 7 is difficult to rotate during an operation using the power tool 1A, for example, the entire power tool 1A may suddenly rotate. The acceleration detection circuit 108 detects such a sudden rotation (sudden movement) of the power tool 1A. The acceleration detection circuit 108 sends a detection signal of the acceleration corresponding to the sudden movement of the power tool 1A to the microcomputer 100.

[0068] The step-down circuit 103 is connected to the storage battery 20 via a wire 206. The step-down circuit 103 reduces the supply voltage from the storage battery 20.

[0069] The control system power supply circuit 104 converts the output voltage from the step-down circuit 103 into an operating voltage (e.g., 5V) of the microcomputer 100 and supplies it to the microcomputer 100. The trigger switch 11 is provided at a position different from the current path (i.e., the wire 204) connecting the storage battery 20 and the motor 4. The microcomputer 100 acquires the operation signal of the trigger switch 11. The microcomputer 100 controls the motor 4 based on the operation signal of the trigger switch 11.

[0070] The battery voltage detection circuit 105 detects the voltage of the storage battery 20. The battery voltage detection circuit 105 sends a detection signal of the voltage of the storage battery 20 to the microcomputer 100.

[0071] The over-discharge detection circuit 106 is connected to the LD terminal (a terminal for protection function) of the storage battery 20. The over-discharge detection circuit 106 detects over-discharge based on the voltage of the LD terminal. The over-discharge detection circuit 106 sends a detection signal of the over-discharge of the LD terminal to the microcomputer 100.

[0072] The current detection circuit 107 detects the current flowing through the motor 4 based on the voltage across both ends of the resistor Rs. The current detection circuit 107 sends a detection signal of the current flowing through the motor 4 to the microcomputer 100.

[0073] The control signal output circuit 101 outputs a control signal for controlling the on / off of the switching elements constituting the inverter circuit 81 based on the control signal from the microcomputer 100.

[0074] The rotor position detection circuit 102 detects the position of the rotor 42 of the motor 4 based on the output voltage of the magnetic sensor 91 on the sensor substrate 9. The rotor position detection circuit 102 sends a detection signal of the position of the rotor 42 to the microcomputer 100.

[0075] Based on the detection signal of the sensor substrate 9 sent from the rotor position detection circuit 102, the microcomputer 100 outputs a control signal for controlling the inverter circuit 81 from the control signal output circuit 101. The control signal output circuit 101 outputs a control signal to the inverter circuit 81, thereby switching the current supplied from the storage battery 20 to the coil 41D of the motor 4. In the case where, for example, six coils 41D are provided, the microcomputer 100 controls the switching elements of the inverter circuit 81 so that the two coils 41D in the first group become the U-phase coils, the two coils 41D in the second group become the V-phase coils, and the two coils 41D in the third group become the W-phase coils. Thus, the rotor 42 of the motor 4, which is a DC brushless motor, rotates by the current supplied from the storage battery 20.

[0076] It should be noted that, as Figure 1 shown, a battery remaining amount display circuit 109 is provided in the storage battery 20. The battery remaining amount display circuit 109 notifies the operator of the remaining amount of the storage battery 20.

[0077] [Wiring Structure]

[0078] Figure 4 is a diagram for explaining the wiring structure of the electric tool 1A according to the embodiment. As Figure 2 , Figure 3 and Figure 4As shown, the control signal output circuit 101 of the control circuit board 10 and the inverter circuit board 8 are connected by the first signal line 201. The control signal output circuit 101 of the control circuit board 10 outputs a control signal for controlling the inverter circuit board 8. The control signal output from the control signal output circuit 101 of the control circuit board 10 is sent to the inverter circuit board 8 via the first signal line 201. At least a part of the first signal line 201 connecting the control signal output circuit 101 of the control circuit board 10 and the inverter circuit board 8 is housed in the connection part 23. The first signal line 201 passes through the internal space of the connection part 23.

[0079] The upper end of the first signal line 201 is connected to the lower surface of the inverter circuit board 8. The lower end of the first signal line 201 is connected to the upper surface of the control circuit board 10. The first signal line 201 connected to the lower surface of the inverter circuit board 8 passes under the power transmission mechanism 6. After being pulled forward under the power transmission mechanism 6, the first signal line 201 passes through the internal space of the connection part 23 and is connected to the upper surface of the control circuit board 10.

[0080] The rotor position detection circuit 102 of the control circuit board 10 and the sensor board 9 are connected by the second signal line 202. The sensor board 9 outputs a detection signal of the rotation of the motor 4. The detection signal output from the sensor board 9 is sent to the rotor position detection circuit 102 of the control circuit board 10 via the second signal line 202. At least a part of the second signal line 202 connecting the sensor board 9 and the rotor position detection circuit 102 of the control circuit board 10 is housed in the connection part 23. The second signal line 202 passes through the internal space of the connection part 23.

[0081] As described above, the sensor board 9 is arranged further back than the stator core 41A of the motor 4. The upper end of the second signal line 202 is connected to the lower part of the sensor board 9. The second signal line 202 passes behind the inverter circuit board 8 and then passes under the inverter circuit board 8. After passing under the inverter circuit board 8, the second signal line 202 is pulled to under the power transmission mechanism 6. After being pulled forward under the power transmission mechanism 6, the second signal line 202 passes through the internal space of the connection part 23 and is connected to the upper surface of the control circuit board 10.

[0082] The microcomputer 100 on the control circuit board 10 and the switch body 11B are connected by the third signal line 203. The switch body 11B outputs an operation signal for driving the motor 4. The detection signal output from the switch body 11B is sent to the microcomputer 100 on the control circuit board 10 via the third signal line 203. At least a part of the third signal line 203 connecting the trigger switch 11 and the microcomputer 100 on the control circuit board 10 is accommodated in the grip portion 22. The third signal line 203 passes through the internal space of the grip portion 22.

[0083] The upper end portion of the third signal line 203 is connected to the lower portion of the switch body 11B. The lower end portion of the third signal line 203 is connected to the upper surface of the control circuit board 10.

[0084] The microcomputer 100 on the control circuit board 10 and the clutch dial 15 are connected by the fourth signal line 207. The clutch dial 15 outputs an operation signal for setting the current value to stop the motor 4. The detection signal output from the clutch dial 15 is sent to the microcomputer 100 on the control circuit board 10 via the fourth signal line 207. At least a part of the fourth signal line 207 connecting the clutch dial 15 and the microcomputer 100 on the control circuit board 10 is accommodated in the battery holding portion 24. The fourth signal line 207 passes through the internal space of the battery holding portion 24.

[0085] One end portion of the fourth signal line 207 is connected to the clutch dial 15. The other end portion of the fourth signal line 207 is connected to the upper surface of the control circuit board 10.

[0086] The battery side terminal 301 and the tool side terminal 302 can be connected. The wire 204 through which the current supplied from the battery holding portion 24 to the motor 4 passes is connected to the tool side terminal 302.

[0087] At least a part of the wire 204 through which the current supplied from the battery holding portion 24 to the motor 4 passes is accommodated in the connection portion 23. The drive current supplied to the inverter circuit board 8 via the wire 204 is supplied to the connection member 41E of the motor 4 via the wire 205.

[0088] The wire 206 branches off from the lower part of the wire 204. The battery 20 (tool side terminal 302) and the step-down circuit 103 on the control circuit board 10 are connected by the wire 206. The drive current for driving the motor 4 is output from the battery 20. The drive current output from the battery 20 is supplied to the step-down circuit 103 on the control circuit board 10 via the wire 206.

[0089] The upper end of the wire 204 is connected to the lower surface of the inverter circuit board 8. The lower end of the wire 204 is connected to the tool-side terminal 302. The upper end of the wire 205 is connected to the coil 41D (connecting member 41E). The lower end of the wire 205 is connected to the upper surface of the inverter circuit board 8. The wire 204 connected to the lower surface of the inverter circuit board 8 passes under the power transmission mechanism 6. The wire 204 pulled forward under the power transmission mechanism 6 passes through the internal space of the connecting portion 23 and is then connected to the tool-side terminal 302 of the battery assembly portion 19.

[0090] [Effect]

[0091] As described above, according to the embodiment, the inverter circuit board 8 is housed in the main body portion 21. The motor 4 and the fan 5 for cooling the motor 4 are housed in the main body portion 21. By the rotation of the fan 5, air flows on the surface of the motor 4, and thus, the motor 4 is cooled. In the present embodiment, by the rotation of the fan 5, air also flows on the surface of the inverter circuit board 8, and thus, not only the motor 4 is cooled, but also the inverter circuit board 8 is cooled. If a high current flows through the inverter circuit board 8, the temperature of the inverter circuit board 8 may rise. In the present embodiment, since the inverter circuit board 8 is cooled, the rise in the temperature of the inverter circuit board 8 is suppressed.

[0092] If the temperature of the inverter circuit board 8 rises, it may be necessary to reduce or stop the output of the motor 4 for the heat dissipation of the inverter circuit board 8. If the output of the motor 4 is reduced or stopped, the workability of using the power tool 1A is reduced. According to the present embodiment, even if a high current flows through the inverter circuit board 8, since the rise in the temperature of the inverter circuit board 8 is suppressed, the reduction in the workability of using the power tool 1A is also suppressed.

[0093] At least a part of the inverter circuit board 8 is disposed between the fan 5 and the air inlet 18A. Therefore, the air flowing into the internal space of the main body portion 21 from the air inlet 18A by the rotation of the fan 5 can flow toward the fan 5 after contacting the surface of the inverter circuit board 8. Thereby, the inverter circuit board 8 is sufficiently cooled.

[0094] In the front-rear direction, the fan 5 is disposed more forward than the center of the inverter circuit board 8, and the air inlet 18A is disposed more rearward than the center of the inverter circuit board 8. Thereby, the air flowing into the internal space of the main body portion 21 from the air inlet 18A can sufficiently contact the surface of the inverter circuit board 8.

[0095] The inverter circuit board 8 is arranged in the main body portion 21 below the motor 4. Since the inverter circuit board 8 and the motor 4 are arranged side by side, an increase in the size of the power tool 1A in the front-rear direction is suppressed. In addition, the air flowing into the internal space of the main body portion 21 from the air inlet 18A can come into sufficient contact with the surfaces of the motor 4 and the inverter circuit board 8 respectively. In addition, the first signal line 201 and the second signal line 202 can connect the inverter circuit board 8 and the control circuit board 10 without passing through the motor 4.

[0096] The control circuit board 10 is housed in the battery holding portion 24. Thereby, the internal space of the battery holding portion 24 is effectively utilized. In addition, since the control circuit board 10 is not arranged in the internal space of the main body portion 21, it is not necessary to enlarge the main body portion 21.

[0097] The first signal line 201 connecting the control circuit board 10 and the inverter circuit board 8 passes through the internal space of the connecting portion 23 and does not pass through the internal space of the gripping portion 22. Thereby, the internal space of the connecting portion 23 is effectively utilized. In addition, since the first signal line 201 is not arranged in the internal space of the gripping portion 22, it is not necessary to thicken the gripping portion 22.

[0098] The upper end portion of the first signal line 201 is connected to the lower surface of the inverter circuit board 8. Thereby, excessive bending of the first signal line 201 can be suppressed.

[0099] The second signal line 202 connecting the sensor board 9 and the control circuit board 10 passes through the internal space of the connecting portion 23 and does not pass through the internal space of the gripping portion 22. Thereby, the internal space of the connecting portion 23 is effectively utilized. In addition, since the second signal line 202 is not arranged in the internal space of the gripping portion 22, it is not necessary to thicken the gripping portion 22.

[0100] The upper end portion of the second signal line 202 is connected to the lower portion of the sensor board 9. The sensor board 9 is arranged behind the stator core 41A. The second signal line 202 passes behind the inverter circuit board 8. Thereby, excessive bending of the second signal line 202 can be suppressed.

[0101] The third signal line 203 connecting the trigger switch 11 and the control circuit board 10 passes through the internal space of the gripping portion 22 and does not pass through the internal space of the connecting portion 23. Thereby, the third signal line 203 can be shortened.

[0102] The wire 204 connecting the battery holding portion 24 and the motor 4 passes through the internal space of the connecting portion 23 and does not pass through the internal space of the gripping portion 22. Thereby, the internal space of the connecting portion 23 is effectively utilized. In addition, since the wire 204 is not arranged in the internal space of the gripping portion 22, it is not necessary to thicken the gripping portion 22.

[0103] The upper end portion of the wire 204 is connected to the lower surface of the inverter circuit board 8. Thereby, excessive bending of the wire 204 can be suppressed.

[0104] The lower end portion of the holding portion 22 and the lower end portion of the connecting portion 23 are respectively connected to the battery holding portion 24. Thereby, the strength of the lower portion of the housing 2 is improved.

[0105] As Figure 4 shown, in the case where an imaginary line VL connecting the front end portion of the output portion 7 and the lower end portion of the front portion of the battery 20 is defined, the clutch dial 15 is arranged to be more rearward than the imaginary line VL. Thereby, for example, even if the power tool 1A is placed on the floor surface or the power tool 1A falls onto the floor surface, contact between the clutch dial 15 and the floor surface can be suppressed. Therefore, damage to the clutch dial 15 can be suppressed.

[0106] The interface panel 16 is arranged on the upper surface of the battery holding portion 24. In the front-rear direction, the interface panel 16 is arranged between the holding portion 22 and the connecting portion 23. That is, the interface panel 16 is arranged inside the space surrounded by the holding portion 22, the connecting portion 23, and the battery holding portion 24. The interface panel 16 is protected by the holding portion 22, the connecting portion 23, and the battery holding portion 24. Therefore, damage to the interface panel 16 can be suppressed.

[0107] [Other Embodiments]

[0108] In the above embodiment, the inverter circuit board 8 and the control circuit board 10 are separate boards, the inverter circuit board 8 is housed in the main body portion 21, and the control circuit board 10 is housed in the battery holding portion 24. The inverter circuit board 8 and the control circuit board 10 can be integrated.

[0109] Figure 5 is a diagram for explaining the wiring structure of the power tool 1B according to other embodiments. As Figure 5 shown, the inverter circuit board 8 and the control circuit board 10 which are integrated into a controller board 810 can be housed in the main body portion 21. The controller board 810 is housed in the housing 810C. In Figure 5 the example shown, the first signal line 201 is omitted. The second signal line 202 is arranged to connect the lower portion of the sensor board 9 and the upper surface of the controller board 810. The third signal line 203 is arranged to connect the upper portion of the switch body 11B and the lower surface of the controller board 810. The wire 204 is arranged to connect the lower surface of the controller board 810 and the battery assembly portion 19. The wire 205 is arranged to connect the upper surface of the controller board 810 and the coil 41D (connecting member 41E).

[0110] In the above-described embodiment, the rotation of the fan 5 causes the air in the external space of the main body portion 21 to flow into the internal space of the main body portion 21 via the intake port 18A. Alternatively, the rotation of the fan 5 may cause the air in the external space of the main body portion 21 to flow into the internal space of the main body portion 21 via the exhaust port 18B, and the air in the internal space of the main body portion 21 to flow out of the internal space of the main body portion 21 via the intake port 18A. In this case, the exhaust port 18B functions as an intake port, and the intake port 18A functions as an exhaust port. Further, in the front-rear direction, the fan 5 may be disposed more rearward than the center of the inverter circuit board 8. Regarding the fan 5, for example, the fan 5 is disposed more rearward than the stator core 41A.

[0111] In the above-described embodiment, the power tool is a vibration-driven drill. The power tool is not limited to a vibration-driven drill. Examples of the power tool include a drive drill, an angle drill, an impact driver, a hammer, a hammer drill, and a reciprocating saw.

Claims

1. An electric tool, characterized in that, Comprising: A motor; A fan; A main body portion that extends in the front-rear direction and houses the motor and the fan; A gripping portion that extends downward from the lower portion of the main body portion; A connecting portion that is arranged more forward than the gripping portion, extends downward from the lower portion of the main body portion, and is arranged more forward than the motor; A battery holding portion that is connected to the lower end portion of the gripping portion and the lower end portion of the connecting portion; A battery mounting portion that is provided at the lower portion of the battery holding portion for loading and unloading a battery; An inverter circuit board that is housed in the main body portion and switches the current supplied from the battery mounted on the battery mounting portion to the motor; A sensor board that is housed in the main body portion and has a magnetic sensor for detecting the rotation of the motor; And A control circuit board that is housed in the battery holding portion and outputs a control signal for controlling the switching elements of the inverter circuit board, The inverter circuit board is arranged lower than the motor in the main body portion, and the rear end portion of the inverter circuit board is arranged more rearward than the gripping portion, The sensor board is arranged around the rotor shaft of the motor in the main body portion, At least a part of a wire serving as a current path that has a lower end portion connected to a tool-side terminal of the battery mounting portion and an upper end portion connected to the lower surface of the inverter circuit board and connects the battery and the motor is housed in the connecting portion, The wire connected to the lower surface of the inverter circuit board passes through the lower portion of the main body portion between the connecting portion and the gripping portion and is pulled forward, passes through the internal space of the connecting portion, and then is connected to the tool-side terminal of the battery mounting portion.

2. An electric tool, characterized in that, Comprising: A motor; A fan that is arranged more forward than the stator core of the motor; A main body portion that extends in the front-rear direction and houses the motor and the fan; A gripping portion that extends downward from the lower portion of the main body portion; A connecting portion that is arranged more forward than the gripping portion and extends downward from the lower portion of the main body portion; A battery holding portion that is connected to the lower end portion of the gripping portion and the lower end portion of the connecting portion; A battery mounting portion that is provided at the lower portion of the battery holding portion for loading and unloading a battery; An inverter circuit board that is housed in the main body portion and switches the current supplied from the battery mounted on the battery mounting portion to the motor; A sensor board that is housed in the main body portion and detects the rotation of the motor; And A control circuit board that is housed in the battery holding portion and outputs a control signal for controlling the switching elements of the inverter circuit board, and the main body portion has: An air inlet for the air flow that flows from the external space of the main body portion into the internal space of the main body portion through the rotation of the fan; and an air outlet for the air flow that flows out from the internal space to the external space, and the air outlet is arranged more forward than the air inlet. The inverter circuit board is arranged lower than the motor in the main body portion, and at least a part of the inverter circuit board is arranged between the fan and the air inlet. The sensor board is arranged more rearward than the stator core of the motor in the main body portion. The height of the air inlet is the same as the height of the air outlet, and it is arranged above the inverter circuit board. The air flowing into the internal space of the main body portion from the air inlet contacts the motor and the inverter circuit board at the same time to cool the motor and the inverter circuit board.

3. The power tool according to claim 2, wherein In the front-rear direction, the fan is arranged more forward than the center of the inverter circuit board, and the air inlet is arranged more rearward than the center of the inverter circuit board.

4. The power tool according to claim 2, wherein At least a part of the first signal line connecting the control circuit board and the inverter circuit board is housed in the connecting portion.

5. The power tool according to claim 4, wherein The first signal line is connected to the lower surface of the inverter circuit board.

6. The power tool according to claim 1 or 2, wherein At least a part of the second signal line connecting the sensor board and the control circuit board is housed in the connecting portion.

7. The power tool according to claim 6, wherein The second signal line passes through from the rear of the inverter circuit board.

8. The power tool according to claim 1 or 2, wherein The power tool is provided with a trigger switch, which is arranged on the gripping portion, and the trigger switch is operated to drive the motor. At least a part of the third signal line connecting the trigger switch and the control circuit board is housed in the gripping portion.

9. The power tool according to claim 1 or 2, wherein The wire for the current supplied from the battery holding portion to the motor is connected to the lower surface of the inverter circuit board.

10. The power tool according to claim 9, wherein At least a part of the wire is housed in the connecting portion.

Images