JP6761838B2 - Electric impact tool - Google Patents

Description

The present invention relates to an electric impact tool that drives a motor using a battery pack as a power source.

As a power tool, a so-called DC tool is known in which a battery pack mounted on a housing is used as a power source to drive a motor to operate an output unit. As disclosed in Non-Patent Document 1, such a DC tool includes a motor corresponding to a battery pack having a predetermined rated voltage.

"Makita General Catalog 2016-4", [online], pp. 8-12, [Search on April 21, 2016], Internet <URL: http://ecatalog.makita.co.jp/flash/administrator/ 20 / # 12 ＞

If the rated voltage of the battery pack is increased (for example, 18V) in order to obtain a large amount of power, the size of the motor (outer diameter of the stator) is increased accordingly, which leads to an increase in the size of the housing for accommodating the motor. For this reason, it becomes difficult to handle in a narrow work place.

Therefore, an object of the present invention is to provide an electric impact tool which can maintain compactness even when a battery pack having a large rated voltage is used and is excellent in usability.

In order to achieve the above object, the invention according to claim 1 includes a motor housing extending in the front-rear direction and accommodating a brushless motor having a maximum left-right width of 40 mm or less.
A hammer rotated by a brushless motor and
Anvil that is hit in the direction of rotation by a hammer,
A grip that connects to the bottom of the motor housing and extends downward,
The battery mounting part that connects to the bottom of the grip part and
A battery pack with a rating of 18V, which is mounted on the battery mounting part and has an outer shape that is longer in the front-back direction than in the left-right direction,
The control circuit board placed inside the battery mount and
It has a switch panel that has an operation unit and a display unit and is provided on the upper surface of the battery mounting unit and has a width smaller than that of the control circuit board.
The motor housing is located above the switch panel
The left and right width of the switch panel is formed smaller than the maximum left and right width of the motor housing.
The switch panel is located within the maximum lateral width of the motor housing in plan view.
The motor housing has a tubular shape whose axis extends in the front-rear direction, and the distance from the axis to the maximum height position of the motor housing is 27 mm or less.
The maximum left-right width of the motor housing and the maximum left-right width of the battery pack have the following relationship.
Maximum left / right width of motor housing / Maximum left / right width of battery pack <0.75

According to the present invention, compactness can be maintained even if a battery pack having a rated voltage of 18 V is used, and the usability is excellent.

It is a side view of an impact driver. It is a front view of an impact driver. It is an enlarged plan view of an impact driver. It is a central vertical sectional view of an impact driver. It is an enlarged sectional view taken along line AA of FIG. It is an enlarged view of the screw boss part on the upper side of a brushless motor. It is explanatory drawing of the state which the impact driver is placed horizontally. In the explanatory view comparing the maximum cross-sectional area of the main body and the battery pack, (A) shows the main body and (B) shows the maximum cross section of the battery pack. It is a side view of an impact driver equipped with battery packs having different rated capacities. It is a side view of the impact driver which shows the modification example of a display part. It is a front view (partial cross section) of the impact driver which shows the modification example of a display part. It is a side view of the impact driver which shows the modification example of the main body part. It is a front view of the impact driver which shows the modification example of the main body part. It is a central vertical sectional view of the impact driver which shows the modification example which tilted the main body part. It is a front view of the impact driver which shows the modification example which tilted the main body part. It is a central vertical sectional view of a driver drill. It is a front view of a driver drill. It is explanatory drawing of the system which uses a common DC tool and uses a battery pack properly. It is explanatory drawing of the system which uses a common battery pack and uses DC tools properly. It is explanatory drawing of the set of two types of DC tools and a battery pack.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 is a side view of an impact driver which is an example of a power tool, FIG. 2 is a front view, FIG. 3 is an enlarged plan view, FIG. 4 is a central vertical sectional view, and FIG. 5 is an enlarged sectional view taken along line AA of FIG. Is.
The impact driver 1 has a main body portion 2 having a central axis in the front-rear direction and a grip portion 3 protruding downward from the main body portion 2, and a battery mounting portion 4 provided at the lower end of the grip portion 3 has a power supply. The battery pack 5 is installed. A switch 6 in which the trigger 7 is projected forward is housed in the upper part of the grip portion 3, and a forward / reverse switching lever 8 of the motor is provided on the upper side of the switch 6. The battery mounting portion 4 is provided with a terminal block 9 having a terminal plate 10 and a controller 11 having a control circuit board 12 on which a microcomputer, a switching element, or the like is mounted. Further, on the upper surface of the battery mounting unit 4, a button switch 14 as an operation unit for switching torque and striking force, and a display unit 15 for displaying the current torque and striking force and the remaining capacity of the battery pack 5 are provided. A switch panel 13 is provided.

The battery pack 5 is provided with terminals (not shown) that are electrically connected to the terminal plate 10 of the terminal block 9 on the upper surface of the box-shaped case 16 that accommodates a plurality of cells (here, a lithium ion battery), and is provided on both the left and right sides. A pair of rail portions 18, 18 that are fitted between the guide portions 17, 17 provided on the left and right sides of the battery mounting portion 4 are provided. Reference numeral 19 denotes a hook that protrudes upward from the case 16 and engages with the recess 20 provided on the front lower surface of the battery mounting portion 4 to prevent the battery from coming off. The button 21 provided on the front surface of the case 16 enters the case 16. The battery pack 5 can be removed by pushing it in. The rated voltage of this battery pack 5 is 18V.

The brushless motor 22 and the hammer case 23 are housed in the main body 2 in this order from the rear. Inside the hammer case 23, a planetary gear reduction mechanism 24 that decelerates the rotation of the rotating shaft 46 of the brushless motor 22, a spindle 25 that decelerates and rotates by the planetary gear reduction mechanism 24, and a striking operation are added to the rotation of the spindle 25. The striking mechanism 26 and the anvil 27 serving as the final output shaft are internally provided, and the anvil 27 projects forward from the front end of the main body 2. The hammer case 23 including the anvil 27 serves as an output unit. A bit insertion hole 28 and a sleeve 29 for attaching / detaching the inserted bit are provided at the tip of the anvil 27, and a rubber bumper 30 is externally attached to the front part of the hammer case 23 behind the sleeve 29. Has been done.

The latter half of the main body 2 has a tubular motor housing 31 that accommodates the brushless motor 22 and is integrated with the grip 3, and the motor housing 31 and the grip 3 are half of the motor housing 31. It is formed by assembling a pair of left and right half-split housings HR, HL in which the grip portion 3 and the half of the grip portion 3 are integrally molded by a plurality of screws 32, 32. The rear end of the motor housing 31 is closed by forming exhaust ports 33, 33 ... On the side surface, and intake ports 34, 34 ... Are formed on the side surface of the motor housing 31 in front of the exhaust port 33. ing.

Further, in the half-split housings HR and HL, among the screw bosses for screwing, as shown in FIG. 6, the screw boss 35 located on the upper side of the brushless motor 22 has a chamfered portion 36 formed on the lower surface thereof. It can be arranged below (closer to the brushless motor 22) together with the upper portion of the minute motor housing 31. Further, on the surfaces of the half-split housings HR and HL, the side surface of the motor housing 31, the side surface of the grip portion 3, and the side surface of the battery mounting portion 4 are protected by integrally molded elastomers 37, 37.

The brushless motor 22 is an inner rotor type having a stator 38 and a rotor 39. First, the stator 38 is provided via a stator core 40 formed by laminating a plurality of steel plates, a front insulating member 41 and a rear insulating member 42 provided before and after the stator core 40, and a front insulating member 41 and a rear insulating member 42. It has a plurality of coils 43, 43 .. wound around the stator core 40, and a sensor circuit board 44 attached to the front insulating member 41 and having rotation detection elements 45, 45 ... Mounted on the rear surface. There is.
The outer diameter of the stator 38 is 38 mm, which is the same as the brushless motor for electric tools used at the rated voltage of 10.8 V, but the coil 43 has a thin wire diameter and the number of turns corresponding to the rated voltage of 18 V. Is increasing. Combined with the outer diameter of the stator 38 and the shape of the screw boss 35, the maximum diameter of the motor housing 31 including the elastoma 37 is suppressed to 55 mm.

The rotor 39 includes a rotating shaft 46 located at the axis, a tubular rotor core 47 arranged around the rotating shaft 46, and permanent magnets 48, 48, etc. held in the rotor core 47. Have. A pinion 49 is attached to the front end of the rotating shaft 46, a bearing 50 is attached to the rear thereof, and a centrifugal fan 51 is attached to the inside of the exhaust ports 33, 33 ... At the rear end of the rotating shaft 46. A bearing 52 is assembled behind it. The bearing 52 is held on the rear inner surface of the motor housing 31. The front end of the rotating shaft 46 penetrates the bearing retainer 53 held in the motor housing 31 in front of the brushless motor 22 and projects forward, and the bearing 50 is held by the bearing retainer 53.

The bearing retainer 53 has a metal disk shape, and a locking rib 54 provided on the inner surface of the motor housing 31 is locked to a constricted portion formed in the center, so that movement in the front-rear direction is restricted. It is held in the motor housing 31. A ring wall 55 having a male screw portion formed on the outer circumference thereof is projected forward from the front peripheral edge of the bearing retainer 53, and the ring wall 55 is screwed into the rear end of the hammer case 23 to the rear portion of the hammer case 23. Is blocked. The hammer case 23 is a metal tubular body having a tapered front half, and a front tubular portion 56 is formed at the front end thereof, and is engaged with the inner surface of the motor housing 31 to prevent rotation.

At the front of the bearing retainer 53, the rear end of the spindle 25 is pivotally supported via the bearing 57. The spindle 25 has a hollow and disc-shaped carrier portion 58 at the rear portion, and a pinion 49 of the rotating shaft 46 is projected into a bottomed hole 59 formed from the rear surface at the axial center.
The planetary gear reduction mechanism 24 includes an internal gear 60 having internal teeth and three planetary gears 61, 61 ... Having external teeth that mesh with the internal gear 60. The internal gear 60 has a large diameter portion 62 on the outer peripheral side of the front portion, and the large diameter portion 62 engages with the inner peripheral surface of the hammer case 23 to prevent rotation, and the ring wall 55 and the hammer case 23. The movement in the axial direction is restricted from the step portion 63 provided on the inner circumference of the above. The planetary gear 61 is rotatably supported in the carrier portion 58 by a pin 64 and meshes with the pinion 49.

The striking mechanism 26 includes a hammer 65 mounted on the spindle 25 and a coil spring 66 for urging the hammer 65 forward. First, the hammer 65 has a pair of claws 67, 67 on the front surface, and the balls 68, 68 are fitted so as to straddle the outer cam groove formed on the inner surface and the inner cam groove formed on the surface of the spindle 25. Is coupled to the spindle 25 via. A ring-shaped groove 69 is formed on the rear surface of the hammer 65, and the front end of the coil spring 66 is inserted therein. The rear end of the coil spring 66 is received by the front surface of the carrier portion 58.
The anvil 27 is pivotally supported by a bearing 70 held by the front cylinder portion 56 of the hammer case 23, and at the rear end, a pair of arms 71, 71 that engage with the claws 67, 67 of the hammer 65 in the rotational direction are provided. It is formed. A ridge 72 that extends beyond the rear surface of the front cylinder portion 56 and is close to the arm 71 is projected on the rear surface of the bearing 70, and a resin washer 73 that receives the arm 71 is fitted to the outside of the ridge 72. ing. Further, a fitting hole 74 is formed in the front axial center of the spindle 25, and the rear end of the anvil 27 is coaxially inserted into the fitting hole 74.

An extension portion 75 extending from the half-split housings HR and HL and partially covering the lower surface of the hammer case 23 is formed below the hammer case 23 and between the trigger 7. An LED substrate 76 provided with an LED 77 is housed in the extended portion 75 in a posture in which the LED 77 is directed obliquely upward. A lens 78 is provided in front of the LED 77 and is exposed from a window 79 provided in front of the extending portion 75. Therefore, the light when the LED 77 is turned on is emitted to the front of the anvil 27 via the lens 78.

In the impact driver 1 configured as described above, when the battery pack 5 is slid from the front of the battery mounting portion 4 with the rail portion 18 fitted between the guide portions 17 and 17, each terminal on the upper surface is moved. It is electrically connected to the terminal plate 10 provided on the terminal block 9, and the hook 19 engages with the recess 20 to be mounted in a retaining state.
In this mounted state, as shown in FIGS. 2 and 3, both sides of the battery pack 5 having a width larger than that of the motor housing 31 project to both sides of the motor housing 31 in a plan view. In this case, the ratio of the maximum width _{W B} of the maximum width _{W M} and the battery pack 5 of the motor housing 31 including the elastomer _37, W M / _{W B} has a approximately 0.73.

By thus greater maximum width W _B of the battery pack 5, when placed sideways impact driver 1 in the flat ground surface S as shown in FIG. 7, the forward and reverse switching lever 8 protrudes to the ground surface S side Even if it is in the switching position, it does not come into contact with the ground surface S. That is, since the maximum slide position of the forward / reverse switching lever 8 is inside the ground contact surface S when placed horizontally, accidental switching of the forward / reverse switching lever 8 is prevented.

Further, as shown in FIG. 2, the width W _S of the switch panel 13 is smaller than the maximum width W _M of the motor housing 31 located directly above. By making the left-right width of the switch panel 13 smaller than the left-right width of the motor housing 31 in this way, a falling object from above (or an obstacle located on the upper side when the impact driver 1 is lifted upward) can be prevented. It hits the motor housing 31 of the main body 2 and is less likely to hit the switch panel 13 and the display 15. In particular, the display unit 15, since so not visible from directly above is disposed within the maximum width W _M of the motor housing 31 in a plan view as shown in FIGS. 3 and 5, the display unit 15 also falling object Effectively protected from.

Further, the distance D from the axis L of the rotating shaft 46 of the brushless motor 22 shown in FIG. 4 (the axis of the motor housing 31) to the maximum height position of the main body 2 including the elastoma 37 is 27 mm.
The center of gravity of the entire impact driver 1 is located within the circle G shown in FIG. The position of the center of gravity is within the range of the bottom surface of the battery pack 5 in a plan view, and is within the grip portion 3.
In addition, as shown in FIG. 8, the maximum cross-sectional area of the main body portion 2 including the maximum sectional area A _{B (FIG.} (B)) of the battery pack 5 in the horizontal cross-section, like the motor housing 31 in the horizontal cross-section ( Here, the maximum cross-sectional area A _B of the battery pack 5 is larger than the horizontal cross-sectional area A _H ((A) in the figure) passing through the axis L of the rotating shaft 46.

In the impact driver 1, when the trigger 7 is pushed in to turn on the switch 6, power is supplied to the brushless motor 22 to rotate the rotating shaft 46. That is, the control circuit board 12 of the controller 11 obtains a rotation detection signal indicating the position of the permanent magnet 48 of the rotor 39 output from the rotation detection element 45 of the sensor circuit board 44, acquires the rotation state of the rotor 39, and acquires the rotation state. The ON / OFF of each switching element is controlled according to the rotation state, and a current is sequentially passed through each coil 43 of the stator 38 to rotate the rotor 39 together with the rotating shaft 46.

Then, the planetary gear 61 that meshes with the pinion 49 revolves in the internal gear 60, and the spindle 25 is decelerated and rotated via the carrier portion 58. Therefore, the hammer 65 also rotates to rotate the anvil 27 via the arm 71 with which the claw 67 engages, and the screw can be tightened by the bit. When the screw tightening progresses and the torque of the anvil 27 increases, the hammer 65 retreats against the urging of the coil spring 66 while rolling the ball 68 along the inner cam groove of the spindle 25, and the claw 67 moves back to the arm 71. When separated from, the hammer 65 rotates while advancing by the urging of the coil spring 66 and the guidance of the inner cam groove to engage the claw 67 with the arm 71 again, and generates a rotational impact force (impact) on the anvil 27. .. Further tightening is possible by repeating this process.
On the other hand, when the centrifugal fan 51 rotates with the rotation of the rotating shaft 46, the air taken in from the intake port 34 on the front side passes through the brushless motor 22 to be cooled, and then is discharged from the exhaust port 33 on the rear side.

Thus, according to the impact driver 1 of the above embodiment, the maximum width W _M of the motor housing 31, by the ratio of the maximum width W _B of the battery pack 5 is set to be 0.73, rated voltage 18V Even if the battery pack 5 of the above is used, the compactness can be maintained and the usability is excellent.
However, this _W M / _{W B} are not limited to 0.73, as long as up to about 0.75, for accidental switching prevent compaction and normal and reverse switching lever 8 can be less than 0.75 Is desirable.

Similarly, since the outer diameter of the stator 38 of the brushless motor 22 is 38 mm and the outer diameter of the motor housing 31 is 55 mm, even if the battery pack 5 having a rated voltage of 18 V is used, the motor housing 31 can be made compact in the radial direction. It will be easy to use.
However, the outer diameter of the stator 38 is not limited to 38 mm, and if it is 40 mm or less, the motor housing 31 can be made compact, so it may be set to 40 mm or less.

Further, since the motor housing 31 has a tubular shape in which the axis L extends in the front-rear direction and the distance D from the axis L to the maximum height position of the motor housing 31 is 27 mm, even if a battery pack 5 having a rated voltage of 18 V is used. This leads to a compact motor housing 31 in the height direction, which makes it easy to use even in a narrow space.
However, the smaller the distance D, the more compact it is. Therefore, if the wall thickness of the motor housing 31 can be reduced, it can be made smaller than 27 mm.
In particular, here, since the chamfered portion 36 is formed on the lower surface of the screw boss 35 for assembling the half-split housings HR and HL on the upper side of the brushless motor 22, the distance D can be easily shortened. The distance D can also be shortened by enlarging the chamfered portion 36 or moving the position of the screw boss 35 toward the upper side.

Further, since the center of gravity of the entire tool with the battery pack 5 attached is located in the bottom surface of the battery pack 5 and in the grip portion 3 in a plan view, the structure is well-balanced and does not easily fall over. ..
Further, the maximum cross-sectional area A _H of the main body portion 2 which includes a motor housing 31 in the horizontal direction, the direction of maximum cross-sectional area A _B of the battery pack 5 in the horizontal direction is larger, located below the center of gravity As a result, the whole is stable, and the sense of balance when gripping the grip portion 3 is also good.

As shown in FIG. 9, the height of the battery pack is smaller in the battery pack 5A, which has a small number of cells and a small rated capacity even at the same rated voltage. However, since the maximum width and the maximum cross-sectional area does not change, the maximum of the relationship between the maximum width W _B of the maximum width W _M and the battery pack 5A of the motor housing 31 and the maximum cross-sectional area A _H and battery pack 5A of the main body portion 2 The relationship with the cross-sectional area _AB and the distance D between the axis L of the main body 2 and the maximum height position are the same as those in the above embodiment. However, the center of gravity (circle G) is at a position slightly higher than that in FIG.

Further, the display unit of the remaining capacity is not limited to the case where it is provided on the switch panel as in the above embodiment, and may be provided separately from the switch panel. 10 and 11 show an example thereof. The display unit 15A is housed in the lower part of the motor housing 31 in the left-right direction behind the forward / reverse switching lever 8, and has four scales arranged in the front-rear direction at both ends. The lighting units 81 and 81 are provided. The lighting units 81 and 81 are exposed from the left and right side windows 80 and 80 provided in the motor housing 31, and the remaining capacity is displayed by the number of lighting of the scale in the lighting unit 81. Width in this case it is also the display unit 15A is accommodated within the maximum width W _H of the motor housing 31.

Further, as shown in FIGS. 12 and 13, even an impact driver 1A having a main body portion 2A having a short length in the front-rear direction can use the 18V battery pack 5 (5A) for a 10.8V brushless motor. Is. In the main body 2A, the motor housing 31 has a short tubular shape in the front-rear direction, the rear end thereof is closed by a rear cover 82 having an exhaust port 33, and a resin cover 83 is provided on the outside of the hammer case 23 with the bumper 30. Is provided. Again, the maximum cross-sectional area A of the relationship between the maximum width _{W B} of the maximum width _{W M} and the battery pack 5 of the motor housing 31 (5A) and a maximum cross-sectional area _{A H} and battery pack 5 of the main body portion 2 (5A) relationship is _B, the relationship between the distance D, the maximum width W _M of the width W _S and the motor housing 31 of the switch panel 13 between the axis L and the maximum height position of the main body portion 2 is the same as the above-described embodiment ..

On the other hand, as in the impact driver 1B shown in FIGS. 14 and 15, the main body 2 is tilted so that its axis L1 is downward by a predetermined angle with respect to the axis L in the front-rear direction parallel to the bottom surface of the battery pack 5. You can also do it. By tilting in this way, the force pushing the entire tool from the grip portion 3 is transmitted to the bit without loss during downward work, and the work can be performed easily. When the battery pack 5 side is heavy during downward work, an urging force (rotational force) that tends to tilt upward is applied to the main body 2 centering on the grip portion 3, but this is because the axis L1 is tilted downward. The inclination can be corrected. In the case of FIGS. 14 and 15, the relationship between the maximum width _{W B} of the maximum width _{W M} and the battery pack 5 of the motor housing 31 (5A) and a maximum cross-sectional area _{A H} and battery pack 5 of the main body 2 of the (5A) maximum relationship between the cross-sectional area a _B, the relationship of the distance D, the maximum width W _M of the width W _S and the motor housing 31 of the switch panel 13 between the axis L1 and the maximum height position of the body 2, the form Is the same as.

The present invention is not limited to the impact driver, but can be applied to other power tools. Although FIGS. 16 and 17 exemplify the driver drill 90, the same components as those of the impact driver 1 are designated by the same reference numerals, and duplicate description will be omitted.
In the main body 2 of the driver drill 90, a gear assembly 91 having a deceleration / speed change mechanism 92, a clutch mechanism 93, etc. is provided in front of the brushless motor 22, and a driver mode is provided in the clutch mechanism 93 in front of the gear assembly 91. A torque adjusting ring 94 for switching between the drill mode and adjusting the torque in the driver mode is provided. A drill chuck 96 is provided at the tip of the spindle 95 protruding forward from the gear assembly 91.

Here, too, the outer diameter of the stator 38 of the brushless motor 22 is 38 mm, which is the same as the brushless motor for electric tools used at the rated voltage of 10.8 V, but the coil 43 is a wire corresponding to the rated voltage of 18 V. The diameter is small and the number of turns is large. Combined with the outer diameter of the stator 38 and the shape of the screw boss 35, the maximum diameter of the motor housing 31 is suppressed to 55 mm. Further, the outer diameter of the drill chuck 96 is larger than the outer diameter of the stator 38.

Further, the stator 38 here is shortened in the axial direction by reducing the number of laminated steel plates of the stator core 40, and the grip portion 3 is also located closer to the front of the main body portion 2. As a result, the LED 77, together with the extension portion 75, is located on the front half side at the lower part of the torque adjusting ring 94 and is close to the rear end surface of the drill chuck 96. Therefore, the LED 77, which is a light, becomes closer to the work place in front of the drill chuck 96, and can irradiate brighter. Further, since the grip portion 3 is located on the front side of the main body portion 2, the main body portion 2 can be stably supported and is easy to use.

Also in the driver drill 90, the relationship between the maximum width _{W B} of the maximum width _{W M} and the battery pack 5 of the motor housing 31 (5A) and a maximum cross-sectional area _{A H} and battery pack 5 of the main body portion 2 (5A) The relationship with the maximum cross-sectional area _AB and the relationship with the distance D between the axis L of the main body 2 and the maximum height position are the same as those in the above embodiment.
Further, the light may be below the chuck as long as it is in front of the front half of the operation ring.

The present invention is not limited to the T-type DC tool in which the motor housing is formed in the front-rear direction and the battery pack is attached to the lower end of the grip portion, such as the impact driver and the driver drill of the above-described form. It can also be applied to Marunoco, which is formed in the left-right direction and the battery pack is attached to the handle side, and other DC tools such as multi-tools, jigsaws, hammer drills, etc., in which the battery pack is attached to the rear end of the motor housing in the front-rear direction. is there. The motor is not limited to brushless.

Further, in the above embodiment, the case where only the 18V battery pack is used for the DC tool having the motor for 10.8V is described, but as shown in FIG. 18, the motor M for 10.8V is used. For the DC tool T that you have, you can select 10.8V battery pack B1 and 18V battery pack B2 by interposing an adapter between the battery mounting part and replacing the unitized controller ( A system is also conceivable in which two types of battery packs B1 and B2 having different rated voltages are used properly by sharing the DC tool T so that they can be used by exchanging). It is possible to use three or more types of battery packs properly.

On the contrary, as shown in FIG. 19, the DC tool T1 having the motor M1 for 10.8V and the stator outer diameter for 18V having a small diameter (for example, 44mm) with respect to the battery pack B of 10.8V or 18V. A DC tool T2 having a motor M2 and a DC tool T3 having a motor M3 with a large stator outer diameter (for example, 52 mm) for 18V can be selected and used, and the battery pack B is shared and the motors are different3. A system in which the types of DC tools T1 to T3 are used properly is also conceivable. It is also conceivable to use two types or four or more types of DC tools properly. In the case of the two types, as shown in FIG. 20, the DC tool T1 having the motor M1 for 10.8V, the DC tool T2 having the motor M2 for 18V, and the 18V used for each of the tools T1 and T2. It may be a set with battery packs B and B (there may be one battery pack B).

Further, the rated voltage when making such a set (combination) of DC tools is selected by changing the laminated thickness of the steel plate of the stator core of the stator, as explained in the driver drills of FIGS. 16 and 17. Can be done. That is, the first power tool that can be used by mounting the first battery pack having the first rated voltage (for example, 10.8 V) with the steel plate as the first laminated thickness, and the steel plate as the first laminated thickness. It is also possible to combine it with a second power tool that can be used by mounting a second battery pack having a second rated voltage (for example, 18 V) as a different second laminated thickness.
Similarly, the rated voltage can be selected by changing the wire diameter of the coil of the stator. That is, a first power tool that can be used by mounting a first battery pack having a first rated voltage (for example, 10.8 V) using a first coil on the stator, and a first coil on the stator. It is also possible to combine it with a second power tool that can be used by mounting a second battery pack having a second rated voltage (for example, 18 V) using a second coil having a different wire diameter from the coil.

In the above embodiment, the use of the motor and the battery pack between 10.8V and 18V is described, but the voltage is not limited to this, and the voltage is not limited to this, for example, 18V-36V, 18V-54V, 36V-72V or the like. It can also be used with the voltage of. Note that 10.8V is sometimes referred to as 12Vmax, and 18V is sometimes referred to as 20Vmax.

1,1A, 1B ... Impact driver, 2,2A ... Main body part, 3 ... Grip part, 4 ... Battery mounting part, 5,5A ... Battery pack, 8 ... Forward / reverse switching lever, 9 ... Terminal block, 11 ... controller, 12 ... control circuit board, 13 ... switch panel, 14 ... button switch, 15,15A ... display, 16 ... case, 22 ... brushless motor, 23 ... hammer Case, 24 ... planetary gear reduction mechanism, 25 ... spindle, 26 ... striking mechanism, 27 ... anvil, 31 ... motor housing, 35 ... screw boss, 36 ... chamfer, 38 ... stator, 39・ ・ Rotor, 46 ・ ・ Rotating shaft, 65 ・ ・ Hammer, 66 ・ ・ Coil spring, 75 ・ ・ Extension part, 77 ・ ・ LED, 90 ・ ・ Driver drill, 91 ・ ・ Gear assembly, 94 ・ ・ Torque adjustment ring , 95 ... spindle, 96 ... drill chuck, HR ... right half housing, HL ... left half housings, S ... contact surface, _{W M} ... motor maximum width of the _{housing, W} B ... the maximum width, W _S · · width of the switch panel, the maximum cross-sectional area of the a _H · · main body, a maximum cross-sectional area of the _B · · battery pack of the battery pack.

Claims (1)

A motor housing that extends in the front-rear direction and houses a brushless motor with a maximum left-right width of 40 mm or less,
A hammer rotated by the brushless motor and
Anvil that is hit in the direction of rotation by the hammer,
A grip portion that connects to the lower part of the motor housing and extends downward,
The battery mounting part connected to the lower part of the grip part and
A 18V rated battery pack that is mounted on the battery mounting part and has an outer shape that is longer in the front-rear direction than in the left-right direction.
A control circuit board arranged inside the battery mounting portion and
A switch panel having an operation unit and a display unit and provided on the upper surface of the battery mounting unit and having a width smaller than that of the control circuit board is provided.
The motor housing is located above the switch panel
The left-right width of the switch panel is formed to be smaller than the maximum left-right width of the motor housing.
The switch panel is arranged within the maximum lateral width of the motor housing in plan view.
The motor housing has a tubular shape whose axis extends in the front-rear direction, and the distance from the axis to the maximum height position of the motor housing is 27 mm or less.
An electric impact tool characterized in that the maximum left-right width of the motor housing and the maximum left-right width of the battery pack have the following relationship.
Maximum left / right width of motor housing / Maximum left / right width of battery pack <0.75

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