JP6675235B2 - Electric tool - Google Patents

Description

  The present invention relates to an electric power tool such as an impact driver and a circular saw.

  As shown in Patent Literature 1 below, there is known an impact driver having a spindle connected to a rotating shaft of a high-speed low-torque motor via a planetary gear mechanism. A fan for generating a flow of air for cooling the motor and the like is fixed to a rotating shaft of the motor.

Japanese Patent No. 5739271

In the impact driver disclosed in Patent Document 1, the rotation of the motor is reduced by the planetary gear mechanism and transmitted to the spindle, and the fan directly fixed to the rotation shaft of the motor rotates at a high rotation speed, which is sufficient for cooling. An air flow occurs.
On the other hand, by providing a low-rotation high-torque motor, it is conceivable to directly rotate the spindle without the planetary gear mechanism (direct drive).
In this case, if the fan is fixed to the rotating shaft of the direct drive motor, there is a possibility that a sufficient number of rotations for cooling may not be obtained. Therefore, it is conceivable to provide a fan motor separately from the direct drive motor. However, as the number of motors increases and the number of wirings increases, the configuration becomes complicated.
An object of the present invention is to provide a power tool capable of efficiently cooling with a simple configuration.

In order to achieve the above object, an invention according to claim 1 is a motor having a motor shaft, a first speed increasing mechanism for increasing the rotation of the motor shaft, and a first speed increasing mechanism connected to the speed increasing mechanism . 1 fan, and a housing for holding the motor , wherein the first speed increasing mechanism and the first fan are disposed in the housing in a state of being coaxial with the motor shaft,
The first fan cools the motor .
The invention according to claim 2 further includes an output shaft driven by the motor shaft, the motor shaft is oriented in the front-rear direction, and the first fan is a centrifugal fan. There, the output shaft is arranged in front of the motor shaft, said first speed increasing mechanism, Ri planetary gear mechanism der having a planetary gear, the first speed-increasing mechanism and the first fan, It is arranged at the rear end of the motor shaft .
According to a third aspect of the present invention, in the above invention, a second speed increasing mechanism for increasing the rotation of the motor shaft and a second fan connected to the second speed increasing mechanism are further provided. cage, the second speed increasing mechanism is Ri bevel gear mechanism der with bevel gear, the second fan is a centrifugal fan, the second speed increasing mechanism and the second fan is arranged in the front end portion of the motor shaft It is characterized by having been done.
Invention according to claim 4, in the above invention, the motor is characterized in that it comprises a stator, a rotor disposed on the outer periphery thereof, a.
According to a fifth aspect of the present invention, in the above-mentioned invention, a tip tool is attached to the output shaft.

  ADVANTAGE OF THE INVENTION According to this invention, there exists an effect that the power tool which provides the power tool which can cool efficiently with a simple structure can be provided.

FIG. 2 is a right side view of the impact driver according to the first embodiment of the present invention. FIG. 2 is a top view of FIG. 1. FIG. 2 is a central longitudinal sectional view of the impact driver according to the present invention. FIG. 4 is an enlarged top view of FIG. 3. It is AA sectional drawing of FIG. It is a right view of the soft impact driver concerning a 2nd form of the present invention. FIG. 7 is a top view of FIG. 6. FIG. 7 is a longitudinal sectional view of FIG. 6. FIG. 9 is an enlarged top view of FIG. 8. FIG. 11 is a right side view (partially sectional view) of a circular saw according to a third embodiment of the present invention. It is BB sectional drawing of FIG. It is CC sectional drawing (part) of FIG. It is DD sectional drawing of FIG. It is EE sectional drawing of FIG. It is a perspective view of a caulking gun concerning a 4th form of the present invention. FIG. 16 is a central longitudinal sectional view of FIG. 15. It is FF sectional drawing of FIG. It is GG sectional drawing (part) of FIG. FIG. 17 is a (partial) sectional view taken along line HH of FIG. 16. FIG. 18 is a cross-sectional view (part) taken along the line II of FIG. 17. It is JJ sectional drawing (part) of FIG. It is KK sectional drawing (part) of FIG.

Hereinafter, embodiments of the present invention and modifications thereof will be described with reference to the drawings as appropriate.
The front, rear, up, down, left, and right in the embodiment and the modified examples are determined for convenience of explanation, and may change depending on the work situation, the state of the moving member, and the like.
Note that the present invention is not limited to the following embodiments and modified examples.

[First form]
FIG. 1 is a right side view of an impact driver 1 according to a first embodiment of the present invention, which is an example of a power tool and an example of a rotary impact tool, and FIG. 2 is a top view of the impact driver 1. 3 is a central vertical sectional view of the impact driver 1, FIG. 4 is an enlarged view of the upper part of FIG. 3, and FIG. 5 is a sectional view taken along line AA of FIG.
The impact driver 1 has a housing 2 forming an outer shell thereof.
The impact driver 1 includes a cylindrical main body 4 having a central axis in the front-rear direction, and a grip 6 formed to project downward from a lower portion of the main body 4. In FIGS. 1 and 3, the right is the front.
The grip portion 6 is a portion to be gripped by the user, and a trigger type switch lever 8 is provided at the base end of the grip portion 6 so that the user can perform an operation of pulling with a fingertip. The switch lever 8 protrudes from the switch body 9.

In the main body 4 of the impact driver 1, a first fan mechanism 10, a motor 11, a second fan mechanism 12, a spindle 13, a coil-shaped spring 14 as an elastic member, a hammer 16, and an anvil 18 are arranged in this order from the rear side. , Stored coaxially.
The motor 11 is a drive source of the impact driver 1, and its rotation is transmitted to the spindle 13. Then, the rotational force of the spindle 13 is appropriately converted into a rotational impact force (at least one of the rotational force and the impact force) by the hammer 16 or the like (impact mechanism), and the buffer of the spring 14 passed between the spindle 13 and the hammer 16 is buffered. It is transmitted to an anvil 18 as an output shaft while receiving it as appropriate. The anvil 18 is a portion that is rotatable around an axis by receiving a rotational impact force, and receives a bit (tip tool) not shown. A driver can be used as the bit, and the impact driver 1 can be used for screw tightening.

The housing 2 has a half housing left housing 20 and a right housing 22. The left housing 20 has a plurality of screw bosses 23, 23..., And the right housing 22 has screw holes corresponding to the screw bosses 23, 23. The left housing 20 and the right housing 22 are combined by screws 24, 24,... Which enter screw holes and screw bosses 23, 23,.
On the rear side of the left housing 20 (outer part of the main body 4), left rear exhaust ports 20a, 20a,... Are arranged vertically, and the right housing 22 is similarly provided with right rear exhaust ports 22a, 22a. Is provided. Note that the left rear exhaust port 20a and the right rear exhaust port 22a are combined to form a rear exhaust port 21a.
At the upper center of the left housing 20, there are provided upper left intake ports 20b, 20b,... Which extend in the radial direction and are arranged along a circular arc. 22b is provided. Note that the upper left intake port 20b and the upper right intake port 22b are combined to form an upper intake port 21b. An inner peripheral portion of the upper intake port 21b (each inner end of the upper left intake port 20b and the upper right intake port 22b) of the housing 2 is a disk protruding in a disk shape with respect to the periphery thereof. It becomes the shape part 21c.

  A forward / reverse switching lever 26, which is a switch for switching the rotation direction of the motor 11, is provided in a boundary area between the main body 4 and the grip 6 and behind the switch lever 8 so as to penetrate the housing 2 from side to side. ing. A light 28 capable of illuminating the front is provided above the switch lever 8 and in front of the forward / reverse switching lever 26. The light 28 is an LED here, and is provided so as to overlap the switch lever 8 in the vertical direction.

A lower end portion of the grip portion 6 is a battery attachment portion 30 that extends outward with respect to the upper portion, and a battery 31 that is detachable by a battery lever (not shown) is held below the battery attachment portion 30. I have. The battery 31 is a 10.8 V (volt) lithium ion battery, and includes three cells (not shown) in a resin battery case. The cell has a cylindrical shape that is long in the axial direction, and faces in the front-rear direction.
A display 32 is provided on the front upper portion of the battery mounting portion 30 (the upper front portion of the lower portion where the grip portion 6 is widened) to display the remaining battery level and the level of the striking force.
A terminal 33 including a circuit board is housed inside the battery mounting section 30. A switching element for shifting the speed of the motor 11 is mounted on the terminal 33.
The battery 31 is mounted by sliding backward from the front of the battery mounting part 30 with the battery terminal part 31a facing upward and the raised part 31b facing upward and forward. At the time of mounting, the rear part of the raised part 31b hits the front part of the battery mounting part 30, and the battery terminal part 31a contacts the battery receiving terminal part 30a of the battery mounting part 30. In addition, at the time of mounting, a battery claw 31c which is urged upward by an elastic member (not shown) and protrudes from the upper surface of another portion of the battery 31 is provided at a lower front portion of the battery mounting portion 30 at the lower portion of the battery mounting portion. Enter 30b. On the other hand, when removing the battery 31, the user operates the battery button connected to the elastic member of the battery claw 31c, and slides the battery 31 forward while keeping the battery claw 31c out of the battery mounting recess 30b. A battery intake port 31d is opened at the rear center of the battery 31, and a battery vent 31e is opened at the upper rear center of the battery 31. In addition, a battery mounting portion vent 30c is opened at a lower end of the battery mounting portion 30 and at a position corresponding to the battery vent 31e when the battery 31 is mounted. The front end of the mounted battery 31 is disposed forward of the front end of the battery mounting part 30.
Hook grooves 35 to which hooks 34 can be attached are provided at the lower end of the housing 2 and on the left and right of the upper part of the battery attachment portion 30. One hook groove is formed in the left housing 20 (not shown), and the other hook groove 35 is formed in the right housing 22 (see FIG. 1).

The motor 11 is a brushless motor (brushless DC motor), and includes a cylindrical stator 40 arranged in a rib set up inside the housing 2 and a rotor 42 arranged inside the stator 40. (Inner rotor).
The stator 40 has a cylindrical stator core 44 having a plurality of (six) internal teeth protruding inward with the axial direction being the front-rear direction, a front insulating member 46 provided before and after the stator core 44, and a rear It has an insulating member 48 and a plurality of drive coils 50, 50,... Wound around the internal teeth of the stator core 44 via the front insulating member 46 and the rear insulating member 48, respectively. The sensor board 52 is fixed to the rear insulating member 48 with screws. On the front surface of the sensor substrate 52, three magnetic sensors (not shown) are fixed. Further, a total of six coil connection portions 54 are provided on the peripheral edge of the rear surface of the rear insulating member 48 as contacts for electrically connecting each drive coil 50 to the sensor substrate 52. One end of a lead wire 55 is connected to the coil connection portion 54, and the other end of the lead wire 55 is connected to the terminal 33.
The rotor 44 is provided with a motor shaft 56 serving as a rotating shaft (rotor shaft), a cylindrical rotor core 58 disposed around the motor shaft 56, and a cylindrical outer rotor core 58. Have permanent magnets 60 whose polarity is alternately changed in the circumferential direction, and a plurality of sensor permanent magnets (not shown) radially arranged on the rear side (on the sensor substrate 52 side of the stator 40). The rotor core 58, each permanent magnet 60, and the sensor permanent magnet constitute a rotor assembly. The rotor assembly is disposed above the switch main body 9, and by this arrangement, a well-balanced impact driver that is easy to use when gripped can be provided.
A tubular resin sleeve 62 is provided on the motor shaft 56 in front of the rotor core 58. In front of the sleeve 62 is provided a motor front bearing 64 arranged around the front of the motor shaft 56.
By forming the permanent magnets 60, 60,... And the sensor permanent magnets in the rotor assembly integrally, it is also possible to form four plate-like permanent magnets.

The first fan mechanism 10 is arranged around the rear part of the motor shaft 56. The first fan mechanism 10 includes an internal gear 70 having internal teeth, a plurality of planetary gears 72 having external teeth meshing with the internal gear 70, and pins 74 serving as axes of the planetary gears 72. , A single carrier 76 that holds each pin 74 and is located on the rear side of each planetary gear 72, and a centrifugal fan 78. The internal gear 70, each planetary gear 72, each pin 74, and the carrier 76 form a planetary gear mechanism 79.
The internal gear 70 is non-rotatably mounted inside the rear end of the housing 2.
Most of each planet gear 72 and carrier 76 are arranged inside the internal gear 70.
Each pin 74 has a columnar shape with the front-rear direction being the axial direction.
Each planetary gear 72 is provided around the pin 74 so as to be rotatable around the corresponding pin 74.
The carrier 76 is integrally fixed to the rear end of the motor shaft 56.
The centrifugal fan 78 includes a blade portion 78a having a plurality of blades, a gear portion 78b having a smaller diameter than the blade portion 78a, and having a cylindrical shape coaxial with the blade portion 78a, and arranged behind the blade portion 78a. It has a fan bearing 78c. External teeth that mesh with the planetary gears 72 are formed on the outer curved surface of the gear portion 78b. The fan bearing 78c is arranged in the blade portion 78a, and the outer ring is fixed integrally to the blade portion 78a or the gear portion 78b, and the inner ring is fixed integrally to the motor shaft 56. Therefore, the centrifugal fan 78 can rotate relative to the motor shaft 56.
The rear exhaust port 21a is located outside the centrifugal fan 78 (blade portion 78a).
Note that a rear motor bearing 80 is provided behind the carrier 76. The motor rear bearing 80 is mounted in the rear end of the housing 2 and rotatably supports the motor shaft 56.

On the other hand, the second fan mechanism 12 is arranged around the front part of the motor shaft 56 (the front side of the motor front bearing 64). The second fan mechanism 12 has a bevel gear 82 having bevel teeth, a plurality of (upper and lower) fan shafts 84 having outer teeth meshing with the bevel gear 82 at an inner end, and is integrally fixed to each fan shaft 84. , And two centrifugal fans 86 (two in total) provided for each centrifugal fan 86 and mounted on the housing, respectively. The bevel gear 82 and the fan shaft 84 form a bevel gear mechanism 89.
The bevel gear 82 is integrally fixed to the motor shaft 56.
Each fan shaft 84 extends in the vertical direction, and is supported rotatably around the shaft by fan bearings 88, 88 arranged above and below a centrifugal fan 86. The outer end of the fan shaft 84 is a small-diameter portion whose diameter is smaller than that of an inner portion thereof. A fan bearing 88 provided in the small-diameter portion is smaller than the other fan bearing 88. I have.
The number of teeth of the bevel gear 82 is larger than the number of teeth of each fan shaft 84.
The upper fan bearing 88 of the upper fan shaft 84 is contained in the disk-shaped portion 21c of the housing 2.
In addition, the first fan mechanism 10 and the second fan mechanism 12, or a part thereof, can also be components of the motor 11.

The spindle 13 has a disc-shaped portion 13b at a rear portion thereof and in front of a rear end portion 13a. The disc-shaped portion 13b protrudes outward (up, down, left and right) with respect to other portions of the spindle 13, and has a larger diameter than other portions. The ring-shaped rear end of the spring 14 is in contact with the front surface of the disc-shaped portion 13b via a washer. A spindle bearing 90 attached to the housing 2 is disposed on the outer periphery of the disc-shaped portion 13b, and rotatably supports the spindle 13.
The inner diameter of the spindle bearing 90 that receives the rear side of the disc-shaped portion 13b of the spindle 13 is larger than the inner diameter of the motor front bearing 64 held by the bearing retainer 25. The rear surface of the spindle bearing 90 is located before the front surface of the motor front bearing 64, and the spindle bearing 90 and the motor front bearing 64 are arranged so as to be shifted from each other in the front-rear direction. Therefore, the force transmitted from the spindle 13 to the spindle bearing 90 is less likely to be transmitted to the motor front bearing 64, and the motor front bearing 64 and the motor 11 have a long life.
A rear end portion 13a of the spindle 13 projects cylindrically rearward from a rear surface of the disc-shaped portion 13b. The inside of the rear end 13a is a spline hole, and receives a spline formed at the front end 56a of the motor shaft 56. Note that the structure of the rotation locking between the rear end portion 13a of the spindle 13 and the front end portion 56a of the motor shaft 56 is not limited to a spline structure, but may be a hexagonal hole (polygonal hole) and a hexagonal column (polygonal column). It may have a structure.

On the other hand, the hammer 16 has a hollow 16a that is cylindrically recessed from the rear surface to the front, and the hollow 16a includes a front portion of the spring 14, and a plurality of recesses 16a are provided at the bottom (front end) of the hollow 16a. A ring-shaped front end of the spring 14 is disposed via spring balls 92, 92,... And a hammer washer 94.
In addition, between the hammer 16 and the front part of the spindle 13, hammer balls 96, 96 for guiding the hammer 16 mainly in the front-rear direction at the time of hitting are interposed.

The anvil 18 on the front side of the hammer 16 includes an anvil body 18a and a chuck 18b provided around a front portion of the anvil body 18a.
The anvil main body 18a has a pair of extending portions 18c, 18c extending in the radial direction at the rear portion.
An anvil bearing 98 that supports the anvil 18 so as to be rotatable around the axis and not to be displaceable in the axial direction is provided on the front side of the extending portions 18c, 18c. The anvil bearing 98 is attached to a front end inner wall of the housing 2.
At the center of the rear end of the anvil main body 18a, a projection 18d is provided which protrudes rearward in a cylindrical shape. The outer curved surface of the projection 18d is formed as a spline, and the projection 18d is inserted into a spindle front hole 14a which is a spline hole formed rearward from the front end of the spindle 13.
An anvil hole 18e extending rearward from the front end of the anvil main body 18a is formed inside the anvil main body 18a. The anvil hole 18e receives a bit (not shown).

The chuck 18b fixes the bit received in the anvil hole 18e.
The chuck 18b has a chuck sleeve 102, a chuck spring 104, a chuck washer 106, a chuck spring stopper 107, and a plurality of chuck balls 108,108.
The chuck sleeve 102 is a cylindrical member, has a larger inner diameter than the front outer diameter of the anvil body 18a, and has a chuck front hole 110 formed from the front end to the center, and a front outer diameter of the anvil body 18a. And has a chuck ball pressing portion 112 protruding inward from the chuck front hole portion 110.
The chuck spring 104 is housed in the chuck front hole 110.
The chuck washer 106 is disposed inside the front end of the chuck front hole 110 and in front of the chuck spring 104.
The chuck spring stopper 107 is a C-shaped member, and is fixed to the outer surface of the distal end portion of the anvil main body 18a in a state where the chuck spring stopper 107 is disposed in front of the chuck washer 106. The chuck spring stopper 107 stores the chuck spring 104 in the chuck front hole 110 via the chuck washer 106.
The chuck balls 108, 108 are arranged above and below the anvil body 18 a, are exposed in the anvil hole 18 e, and can contact the chuck ball holding portion 112 of the chuck sleeve 102.
When the chuck sleeve 102 is pulled forward while receiving the elastic force of the chuck spring 104, the chuck ball pressing portion 112 is separated from each chuck ball 108, and the bit is easily inserted. Then, when the chuck sleeve 102 is returned to the rear in a state where the rear part of the bit is inserted, the chuck ball pressing portion 112 contacts each chuck ball 108 and presses each chuck ball 108 inward, and presses the bit to release the anvil 18. To be fixed.

An operation example of such an impact driver 1 will be described.
When the operator grips the grip portion 6 and pulls the switch lever 8, power is supplied from the battery 31 to the motor 11 by switching in the switch body portion 9, and the rotation position of the rotor 44 grasped by the magnetic sensor of the sensor substrate 52. Accordingly, the switching element of the terminal 33 performs switching of each drive coil, and the rotor 44 (motor shaft 56) rotates.
By the rotation of the motor shaft 56, the first fan mechanism 10 operates, and the centrifugal fan 78 rotates. That is, the carrier 76 integrated with the motor shaft 56 rotates, and the respective planetary gears 72 rotate in the internal gear 70, and the centrifugal fan 78 meshing with the planet gears 72 in the gear portion 78 b is increased in speed from the rotation speed of the motor shaft 56. In this state, it rotates around the motor shaft 56.
Air is exhausted from the rear exhaust port 21a by the action of the blade portion 78a when the centrifugal fan 78 rotates, and the battery exhaust port 31d (battery vent 31e, battery mounting section vent 30c) and the upper exhaust port 21b are connected to the rear exhaust port. An air flow to 21a is formed (see arrows X and Y in FIG. 3). The internal mechanism of the impact driver 1 including the motor 11 is cooled by the flow of air.
Further, the rotation of the motor shaft 56 operates the second fan mechanism 12 to rotate the centrifugal fans 86, 86. That is, the bevel gear 82 integral with the motor shaft 56 in the front-rear direction rotates and the fan shafts 84, 84 in the vertical direction meshing with the bevel gear 82 rotate, and the centrifugal fans 86, 86 are rotated at a speed higher than the rotation speed of the motor shaft 56. In this state, it rotates around the fan shafts 84,84.
By the rotation of the centrifugal fans 86, 86, an air flow similar to the air flow by the rotation of the centrifugal fan 78 is formed (see arrows X and Y in FIG. 3), and by the simultaneous operation of the centrifugal fans 78, 86, 86. Therefore, the flow of the air becomes stronger than in the case of operating independently, and the cooling efficiency of the internal mechanism is improved.
Further, the rotational force of the motor shaft 62 is directly transmitted to the spindle 13 (without passing through the speed reduction mechanism), and the rotational force of the spindle 13 is directly transmitted to the anvil 18 (direct drive).
The spindle 13 rotates the anvil 18 and guides the hammer 16 to swing (hit) back and forth when the anvil 18 receives a torque equal to or more than a predetermined threshold. At the time of impact, the buffering action of the spring 14 acts on the hammer 16 (and the spindle 13).

The impact driver 1 includes the motor 11 having the motor shaft 56, a speed increasing mechanism (a planetary gear mechanism 79 and a bevel gear mechanism 89) for increasing the rotation of the motor shaft 56, and the centrifugal fans 78 and 86, 86 are provided. Therefore, the rotation speed of the centrifugal fans 78, 86, 86 can be increased with respect to the rotation speed of the motor shaft 56 (anvil 18), and the efficiency of cooling by the centrifugal fans 78, 86, 86 can be improved. It is possible to prevent the motor 11 from being damaged (so-called motor burn) due to an excessive temperature rise or maintenance of the temperature. In particular, when a low-rotation, high-torque motor is used for direct drive as compared with a motor that applies a rotational force to an output shaft via a speed reduction mechanism, the centrifugal fans 78, 86, 86 move the motor shaft 11 relative to the motor shaft 11. When they are fixed together, the centrifugal fans 78, 86, 86 also have a low rotation. However, the impact driver 1 requires the centrifugal fans 78, 86, 86 to operate even if a low-rotation, high-torque motor is used. High rotation can be achieved and insufficient cooling can be avoided.
If the speed increasing mechanism is the planetary gear mechanism 79 having the planetary gears 72, 72,..., The speed can be simply increased when the motor shaft 56 and the centrifugal fan 78 are in the same direction. The speed mechanism can be made compact.
On the other hand, if the speed increasing mechanism is a bevel gear mechanism 89 having a bevel gear 82, the speed can be simply increased when the axis of the motor shaft 56 and the axis of the centrifugal fan 86 are in different directions. The speed increasing mechanism can be made compact while changing the direction of the fan shaft 84 of the centrifugal fan 86.
Further, there is provided an anvil 18 driven by a motor shaft 56, the motor shaft 56 is oriented in the front-rear direction, the anvil 18 is arranged in front of the motor shaft 56, and the centrifugal fan 78 and the planetary gear mechanism 79 is arranged at the axial end (rear end) of the motor shaft 56. Therefore, the centrifugal fan 78 whose speed is increased can be arranged outside the main mechanism, and the impact driver 1 can be formed compact and easy to handle.

The embodiment of the present invention is not limited to the first embodiment, and for example, the following changes can be appropriately made to the first embodiment.
The fan may be something other than a centrifugal fan.
Regarding the fan, only the first fan mechanism (related to the planetary gear mechanism) may be provided, only the second fan mechanism (related to the bevel gear mechanism) may be provided, or at least one of these may be provided. A fan that does not pass through a speed mechanism may be provided. Further, the number of fans in the second fan mechanism may be one, or may be three or more. Even if the total number of fans is smaller than in the first embodiment, since the rotation of the fans is increased, the internal mechanism can be sufficiently cooled.
In the second fan mechanism, a bevel gear may be provided for each fan shaft. In the first fan mechanism, a planetary gear mechanism may be arranged in front of the fan, or a plurality of fans may be provided. The first fan mechanism may be located in front of the motor, and the second fan mechanism may be located behind the motor. At least one of the first fan mechanism and the second fan mechanism may be arranged above or below the motor.

Regarding the planetary gear mechanism, instead of or together with the insertion of the pin into the carrier, the projection may be inserted into the hole, or the claws may be locked. The hole for inserting the pin may be a hole with a bottom.
As the speed increasing mechanism, a belt drive type, a type using a chain and a sprocket, or the like may be used.
The motor may be an outer rotor type in which a rotor is arranged outside the stator (see a third embodiment described later). Further, the motor may be a motor other than the brushless motor. The six switching elements may be arranged on the sensor substrate instead of the terminal. Further, the number of switching elements, drive coils, permanent magnets for sensors, magnetic sensors, and the like can be appropriately increased or decreased. The sensor substrate can be screwed to the front insulating member while being arranged in front of the front insulating member.
The anvil (output shaft) may be omitted and the tip tool may be directly attached to the motor shaft, or one or more intermediate shafts may be interposed between the motor shaft and the output shaft.
The driving of the anvil by the motor does not have to be directly driven. That is, a speed reduction mechanism or a speed increasing mechanism may be arranged between the motor shaft and the spindle, between the spindle and the anvil, and the like.

As the battery, any lithium ion battery of 18 to 36 V such as 14.4 V, 18 V (maximum 20 V), 18 V, 25.2 V, 28 V, 36 V, etc. may be used, or a battery having a voltage of less than 10.8 V or exceeding 36 V may be used. A lithium ion battery may be used, or another type of battery may be used.
The number and arrangement of various members, such as increasing or decreasing the number of housing sections, the number of planetary gears, the number of speed increasing mechanisms and the number of intake and exhaust ports, and changing the switch lever switch type, etc. The size, format, and the like can be changed as appropriate.
Adopting a gear case, omitting the hammer and anvil, further arranging a reduction mechanism such as a two-stage planetary gear mechanism, and projecting the output shaft of the reduction mechanism forward from the gear case so that the tip tool can be used. By fixing the tip tool holding portion to be held to the front portion of the output shaft, a rechargeable driver drill or a vibration driver drill can be provided.
In addition, the direction of the output shaft (tip tool holding portion) is different from the direction of the power portion (the direction of the motor shaft of the motor and the transmission direction of the mechanism for transmitting the rotational force) (to be approximately 90 degrees). The present invention can be applied to any of them.
Further, the present invention can be applied to other rechargeable power tools, power tools connected to a commercial power supply, or garden tools such as cleaners, blowers, or garden trimmers.

[Second embodiment]
FIG. 6 is a right side view of a soft impact driver (oil pulse driver) 201 according to a second embodiment of the present invention, FIG. 7 is a top view of the soft impact driver 201, and FIG. FIG. 9 is an enlarged top view of FIG.
The soft impact driver 201 is the same as the impact driver 1 of the first embodiment except for a striking mechanism or an output shaft (a hammer 16 and an anvil 18). Hereinafter, the same components are denoted by the same reference numerals as in the first embodiment, and the description thereof will not be repeated.

On the front side of the second fan mechanism 12 in the main body portion 4 of the soft impact driver 201, an oil unit 204 having a shaft 202 as an output shaft and applying an appropriate impact to the rotation of the shaft 202 is disposed. The spindle 13, the spring 14, the hammer 16, and the anvil 18 of the first embodiment are omitted.
The motor 11 is a drive source of the soft impact driver 201, and its rotation is directly transmitted to the oil unit 204 (direct drive). The shaft 202 is a portion that rotates around an axis by receiving a rotary impact force.

The oil unit 204 includes a cup-shaped front oil case 210 opened rearward, a cup-shaped rear oil case 212 opened frontward, screws 214 and 214, and an inner ring 216 formed of an elastic material. A ring-shaped plate 218 for holding the ring 216 from behind, a cam 220, balls 222, 222, blades 224, 224, a rear seal ring 226, an output adjustment mechanism 228, a front seal ring 230, and a ring 232 , A shaft bearing 234.
Note that the shaft 202 and the shaft bearing 234 may be treated as independent components related to the output shaft instead of the components of the oil unit 204.

The front oil case 210 has a cylindrical rib 210a that projects cylindrically rearward from the front rear surface. On the inner surface of the side portion of the front oil case 210, a stepped portion 210b whose diameter is enlarged on the rear side with respect to the front side is formed.
The ring 216 is arranged outside the cylindrical rib 210a and inside the side surface of the front oil case 210. The ring 216 is a ring-shaped member formed of a resin (more specifically, a synthetic resin). Gas 216a (air) is sealed inside the ring 216.
Further, a plate 218 is disposed on the rear side of the ring 216, the rear end of the cylindrical rib 210a, and the rear side of the step portion 210b. The plate 218 has gaps 218a, 218a at positions facing each other (up and down in FIGS. 8 and 9), and the periphery of the ring 216 and the rear part of the plate 218 communicate with each other by the gaps 218a. .
Screw holes for screws 214, 214 are formed in portions of the front oil case 210 located in front of the gaps 218a, 218a.

The rear oil case 212 has a cylindrical side wall 212a, a central part 212b on the rear side of the side wall 212a, and a rear part 212c that protrudes cylindrically rearward from the rear part of the central part 212b.
The side wall portion 212a is placed in contact with the opening at the rear of the front oil case 210. A rear seal ring 226 is arranged between the side wall portion 212a and the front oil case 210.
At positions (left and right) facing each other on the inner surface of the side wall portion 212a, a raised portion (not shown) that is raised inward with respect to another inner surface (cylindrical surface) is provided.
The center part 212b covers the rear end of the side wall part 212a. The outer surface of the central portion 212b is cylindrical, and the diameter is smaller than the outer diameter of the side wall portion 212a. That is, at the boundary between the side wall portion 212a and the central portion 212b, a step is formed in which the diameter of the rear part is reduced with respect to the front part and the step is depressed.
An oil unit bearing 240 that rotatably supports the rear oil case 212 (oil unit 204) is disposed outside the central portion 212b. An outer surface portion (rear portion) of the oil unit bearing 240 is fitted into a bearing holding portion which is a rib in the housing 2.
The rear part 212c is formed so as to project cylindrically rearward from the rear surface of the central part 212b. The rear part 212c is smaller in diameter than the central part 212b. The inner hole of the rear portion 212c is a spline hole that receives the spline at the tip end portion 56a of the motor shaft 56.

Inside the front oil case 210 and the rear oil case 212, the rear part of the shaft 202 is placed.
The hole at the center of the plate 218 and the inner surface of the cylindrical rib 210a are in contact with the outer surface of the rear portion of the shaft 202. On the front side of the cylindrical rib 210a, a front seal ring 230 and a ring 232 are provided so as to be in contact with the outer surface of the shaft 202 at the center hole.
On the front side of the front oil case 210, a shaft bearing 234 that rotatably supports the shaft 202 is arranged. The shaft bearing 234 is attached inside the front part of the housing 2. Further, a front seal ring 242 is disposed on the front side of the shaft bearing 234. The front seal ring 242 is in contact with the outer surface of the shaft 202. The front seal ring 242 is attached inside the front part of the housing 2.
Inside the shaft 202, a hole in the front-rear direction over the entire shaft 202 is formed. The front of the hole is a chuck hole 244 in which a bit can be mounted. The chuck 18b is provided outside the chuck hole 244 (at the end of the shaft 202). Further, an output adjusting mechanism 228 is disposed at a central portion of the hole (behind the chuck hole 244) so as to close the hole.
A sealed space is formed by the shaft 202, the front oil case 210, the rear oil case 212, the screws 214 and 214, the output adjustment mechanism 228, various seal rings, and the like, and the sealed space is filled with oil. .
The sealing of the oil into the sealed space is performed in a state where the oil is evacuated through the holes of the screws 214 and 214, and the screws 214 and 214 are inserted after the sealing of the oil.
Further, the oil in the closed space can flow into the rear side of the ring 216 through the gaps 218 a of the plate 218. The ring 216 is capable of contracting in response to the pressure flowing from the adjacent oil flowing rearward. The ring 216 contracts mainly when the gas 216a is compressed, and contracts when the heat of the oil becomes relatively high and the pressure increases.

Further, a cam 220 is disposed at a rear portion of the hole inside the shaft 202 (behind the output adjusting mechanism 228).
The cam 220 has a flat shape (the left and right widths are relatively smaller than the vertical height in the state of FIGS. 8 and 9), and is provided to be rotatable left and right with the shaft 202.
Around the cam 220 (up and down in FIGS. 3 and 4), metal (iron) balls 222, 222 are arranged. Each ball 222 can contact the cam 220. The shaft 202 is provided with a radial hole for receiving each ball 222. The hole communicates with a hole in the front-rear direction of the shaft 202.
A blade 224 is disposed outside each ball 222 (upward or downward in FIGS. 3 and 4). Each blade 224 can simultaneously contact the ball 222 and the inner wall of the rear oil case 212 (side wall portion 212a). When the protrusion of the side wall portion 212a is located on the left and right, the cam 220 is horizontal by rotation, and when the balls 222 and 222 are located on the left and right of the cam 220, the blades 224 and 224 hit the left or right protrusion. . At this time, the radial oil passage hole opened so as to communicate with the rear part of the shaft 202 in the front-rear direction is closed by the cam 220 and the balls 222, 222, and the inside of the rear part of the shaft 202 (the peripheral part of the cam 220). ) Is sealed, and the internal pressure of the sealed portion is higher than the internal pressure of oil in other portions. Due to the increase in the internal pressure of the sealed portion, the position of each blade 224 (the position where the blade 224 is pushed outward by the cam 220 and the ball 222 and can contact the raised portion 96) is held.
The internal pressure of the oil can be adjusted by the output adjusting mechanism 228. The output adjusting mechanism 228 moves back and forth, thereby adjusting the amount of oil passing through the rear portion of the output adjusting mechanism 228, and thereby adjusting the internal pressure of the oil. The output adjusting mechanism 228 is moved back and forth by being rotated by an operating tool inserted into the chuck hole 244.
The shaft 202 of the oil unit 204 is driven to rotate by the motor shaft 56.
A left front exhaust port 250 is provided in a portion of the left housing 20 located on the left side of the oil unit 204, and a right front exhaust port is provided in a portion of the right housing 22 located on the right side of the oil unit 204. Are provided.

An operation example of such a soft impact driver 201 will be described.
When the operator grips the grip portion 6 and pulls the switch lever 8, the rotor 44 (motor shaft 56) rotates.
By the rotation of the motor shaft 56, the first fan mechanism 10 operates, and the centrifugal fan 78 rotates at an increased speed. The air is mainly exhausted from the rear exhaust port 21a by the action of the blade portion 78a when the centrifugal fan 78 rotates, and the air is exhausted from the battery intake port 31d (battery vent 31e, the battery mounting part vent 30c) and the upper intake 21b. The flow of air to the exhaust port 21a is mainly formed (see arrows X and Y in FIG. 8). The internal mechanism of the impact driver 1 including the motor 11 is cooled by the flow of air.
In addition, the rotation of the motor shaft 56 operates the second fan mechanism 12, and the centrifugal fans 86, 86 rotate at an increased speed. By the rotation of the centrifugal fans 86, 86, an air flow similar to the air flow due to the rotation of the centrifugal fan 78 is formed (see arrows X and Y in FIG. 3), and the upper intake port 21b is connected to the left front exhaust port. An airflow to 250 and the right front exhaust port 252 is formed (see arrow Z in FIG. 8).
Actually, since the first fan mechanism 10 and the second fan mechanism 12 operate at the same time, the first fan mechanism 10 and the second fan mechanism 12 generate air flows as indicated by arrows X, Y, and Z. Then, by the simultaneous operation of the centrifugal fans 78, 86, 86, the air flows thereof become stronger than in the case of operating independently, and the cooling efficiency of the internal mechanism is improved.

Further, the torque of the motor shaft 62 is directly transmitted to the oil case 212 after the oil unit 204 (direct drive).
Normally, each blade 224 of the oil unit 204 is held in a state of being in contact with a raised portion of the side wall portion 212a of the rear oil case 212. In this state, the oil passage hole at the rear portion of the shaft 202 is closed by the balls 222, 222 and the cam 220, and a high-pressure oil sealed space is formed around the cam 220, so that the blades 224, 224 are made of high-pressure oil. The positions of the blades 224 and 224 are held by being pressed against the raised portion on the inner surface of the rear oil case 212. Then, the rotation of the rear oil case 212 is transmitted to the shaft 202 via the blades 224, the balls 222, the cam 220, and the oil, and the bit fixed by the chuck 18b is rotated to perform screw tightening and the like.
On the other hand, when the load on the shaft 202 is increased due to, for example, a screw being tightened and the rotation of the shaft 202 is delayed more than the rotation of the rear oil case 212, the impact torque is reduced as follows. Intermittently generated by 204 and provided to shaft 202. That is, the rear oil case 212 and the shaft 202 rotate relatively, the respective blades 224 once move away from the raised portion on the inner surface of the rear oil case 212, and the cam 220 and each ball 222 open each oil passage hole at the rear portion of the shaft 202. Then, the oil sealed space around the cam 220 is opened, each ball 222 and each blade 224 are drawn inward in the radial direction, and each blade 224 reaches the next raised portion on the inner surface of the rear oil case 212 until the rear oil reaches. The relative rotation of the case 212 is allowed. Then, when each blade comes into contact with the next raised portion, the oil-sealed space around the cam 220 is re-sealed and becomes filled with relatively high-pressure oil. The blade 224 is held at the position where it protrudes radially outward and hits the raised portion of the rear oil case 212, the impact torque is transmitted to the shaft 202, and the same operation is repeated as appropriate.
The oil unit 204 can generate an impact torque, and when the impact torque is applied to the shaft 202, it is possible to retighten a screw through a bit.
Even if the volume of the oil expands due to the high temperature due to the operation, the hollow ring 216 is pressed by the oil and contracts, thereby suppressing the increase of the internal pressure due to the oil, and the fluctuation of the internal pressure due to the fluctuation of the oil temperature. Is adjusted by the ring 216.

Also in the above soft impact driver 201, the motor 11 having the motor shaft 56, the shaft 202 driven by the motor shaft 56, and the speed increasing mechanism (the planetary gear mechanism 79 and the bevel gear mechanism 89) for increasing the rotation of the motor shaft 56 , 89) and the centrifugal fans 78, 86, 86 connected thereto, the rotational speed of the centrifugal fans 78, 86, 86 can be increased with respect to the rotational speed of the shaft 202, The efficiency of cooling by the centrifugal fans 78, 86, 86 can be improved, and abnormal temperature rise and motor burn can be prevented.
Further, since the front left exhaust ports 250, 250,... And the right front exhaust ports 252, 252,... Are provided in the housing 2, an air flow (see arrow Z) around the oil unit 204 is formed. The oil unit 204 can be cooled efficiently.

In addition, the said 2nd form has the modification similar to 1st form suitably.
In particular, even when the first fan mechanism is omitted, the same air flow as arrows X, Y, and Z in FIG. 8 occurs. On the other hand, when the second fan mechanism is omitted, the left front exhaust port and the right front exhaust port are intake ports, and the arrow Z is reversed. In this case, if the upper intake port is further omitted, a flow of air from the left front intake port or the right front intake port to the rear exhaust port is formed, and it is also possible to cool internal mechanisms such as an oil unit and a motor.

[Third embodiment]
FIG. 10 is a right side view (partially sectional view) of a circular saw 301 as an example of a hand-held cutting machine according to a third embodiment of the present invention, and FIG. 11 is a sectional view taken along line BB of FIG. 12 is a cross-sectional view (part) of CC of FIG. 10, FIG. 13 is a cross-sectional view of DD of FIG. 10, and FIG. 14 is a cross-sectional view of EE of FIG.
The circular saw 301 is attached to a flat base 302, a main body 306 having a saw blade 304 (tip tool), a handle 307 extending from the main body 306, and a rear end of the main body 306 (a connection portion at the base of the handle 307). Battery 308.

At the front of the base 302, a fan-shaped angular plate 310 is provided which protrudes upward from the upper surface of the base 302. The angular plate 310 extends along the left-right direction, and has an arc-shaped guide groove (not shown).
At the rear of the upper surface of the base 302, a bearing receiving portion 311 protruding upward is provided. The bearing holder 311 has a hole (not shown) extending rearward from the front end.

The main body 306 includes a motor housing 316 that accommodates the motor 314, a blade case 318 that covers the right side of the motor 314 and the upper part of the saw blade 304, and a bearing retainer 319 that is disposed therebetween. A motor housing 316 is attached to the left side of the blade case 318 via a bearing retainer 319.
The motor 314 has a motor shaft 321, and the saw blade 304 is directly attached to a right portion (tip portion) of the motor shaft 321 by using a bolt 322 as a fixing tool, and is directly driven to rotate by the motor 314. (Direct drive). Note that the saw blade 304 passes through a saw blade groove 302 a opened along the front-rear direction in the base 302, and a lower portion of the saw blade 304 protrudes from a lower surface of the base 302.
The bearing retainer 319 is formed so as to have a flange portion projecting up and down and up and down from the outer surface of the cylindrical portion that is long in the left and right direction, and holds the bearing 323 in the cylindrical portion. The bearing 323 rotatably supports the motor shaft 321.

In addition, the main body 306 includes a safety cover 324 that covers a part of the saw blade 304 between or below the blade case 318 and the saw blade 304. As will be described later, the main body 306 can be tilted in the left-right direction with respect to the base 302, and can be swung in the up-down direction. The posture shown in FIG.
The safety cover 324 is provided so as to be swingable around the rotation axis (motor shaft 321) of the saw blade 304, and the lower portion of the saw blade 304 is covered by the swing, and the safety cover 324 is housed in the blade case 318. The lower part of the blade 304 is exposed.
The safety cover 324 includes a lever 325 as an operation unit at the center on the right side. The lever 325 is a member having an L-shaped cross section, and is screwed at a lower portion thereof. The right portion of the lever 325 is located to the right of the blade case 318.

In addition, between the main body 306 and the base 302, an angular 326 disposed on the front side of the blade case 318, a shaft 328 passing through the angular 326, and the angular 326 by clamping the angular plate 326 and the angular plate 310 of the base 302. Is fixed to the angular plate 310 via a pre-fixing mechanism 330.
The angular 326 stands on the base 302 and has a flat F-shape. That is, the angular plate 326 has a shape in which two parallel small plate portions along the front-rear direction protrude from the right side and the center of the rear surface of the flat base plate portion along the left-right direction.
The front lower portion of the blade case 318 is inserted between the small plate portions of the angular 326, and a left-right axis 328 is passed through the small plate portion and the front lower portion. Therefore, the blade case 318 or a member (body 306) integral with the blade case 318 can swing up and down with respect to the angular 326 about the shaft 328. The swing is a kind of rotational movement.
Further, when the front fixing mechanism 330 passing through the guide groove of the angular plate 310 of the base 302 is unclamped, the fixing of the angular plate 326 to the angular plate 310 is released, and the rotation extending in the front-back direction along the guide groove is performed. It can be freely tilted to the left and right with respect to the shaft (not shown), and can be fixed at any position in the guide groove by clamping. Therefore, the main body 306 linked to the angular 326 can be tilted left and right. Note that tilting is a type of rotational movement.

Between the main body 306 and the rear part of the base 302, a belt-shaped depth guide 332 that curves in an arc shape is interposed. The depth guide 332 has a depth guide groove occupying a portion other than the peripheral edge. In addition, the depth guide 332 is arranged so that the width direction of the band shape is along the front-rear direction, and is arranged such that the upper portion is directed forward by the curve of the band shape.
Further, the depth guide 332 is connected to the base 302 so as to be tiltable in the left-right direction. That is, at the lower end of the depth guide 332, a shaft portion 338 extending rearward is provided, and the shaft portion 338 is rotatably inserted into a front hole of the bearing receiving portion 311 of the base 302. The guide 332 is attached to the base 302 so as to be rotatable around a shaft 338 at the lower end thereof.

The main body 306 includes a rear fixing mechanism 340 on the lower left side of the rear of the blade case 318.
The rear fixing mechanism 340 passes through the depth guide groove of the depth guide 332, and can be freely fixed to and released from the depth guide 332. When the rear fixing mechanism 340 is fixed to the depth guide 332, the blade case 318 integrated with the rear fixing mechanism 340 is also fixed to the depth guide 332.
The rear fixing mechanism 340 includes a shaft portion 342 that protrudes leftward from a rear lower portion of the left surface of the blade case 318 and passes through the depth guide groove, and a fixing operation portion provided integrally with the shaft portion 342 at the left portion of the shaft portion 342. The lever 344 is provided.
The lever 344 is a member that is long in the front-rear direction, and the tip (rear) is slightly below the other part (base) and spreads slightly to the left. The position of the lever 344 can be changed by rotating the shaft 342 around the center axis. For example, the (base) of the lever 344 takes a posture (release posture) along the direction of the depth guide 332, or the lever 344 takes a depth. The posture (fixed posture) along the direction intersecting the guide 332 is taken.

The shaft portion 342 of the rear fixing mechanism 340 includes a nut 350 fixed to the blade case 318 with the female screw hole in the left-right direction, and a shaft member 352 having a male screw groove on the right portion that matches the female screw hole of the nut 350. Including.
The lever 344 is fixed to the shaft 352, and the rotation of the lever 344 causes the shaft 352 to rotate together with the lever 344 to enter the nut 350 deeper or return to a shallower direction.
Further, the shaft portion 342 has a right washer 356 and a left washer 358 disposed around a right portion of the shaft body 352. A depth guide 332 is located between the right washer 356 and the left washer 358. The right surface of the right washer 356 can contact the left surface of the nut 350, and the left surface of the left washer can contact the right surface of the step formed on the right portion of the shaft 352.

When the lever 344 assumes the above-mentioned fixed posture, the shaft body 352 enters the nut 350 deeply, the nut 350 and the right portion of the shaft body 352 approach each other, and the right washer 356 and the left washer 358 clamp the depth guide 332, The main body 306 is fixed to the depth guide 332.
On the other hand, when the lever 344 is in the release position described above, the shaft body 352 enters the nut 350 shallowly, the nut 350 and the shaft body 352 are separated, the right washer 356 and the left washer 358 are fully opened, and the The clamp is released, and the fixing of the main body 306 to the depth guide 332 is released.
By releasing the fixing, the main body 306 can swing around the axis 328 along the depth guide groove, and the swing of the main body 306 in the circular saw 301 is allowed. Therefore, the release posture is a movement allowable posture that allows the main body 306 to rotate.
Further, by such fixing, the main body 306 is fixed at an arbitrary position in a swingable range. The swingable range of the main body 306 is from the position where the shaft 342 is at the lower end of the depth guide groove to the position where the shaft 342 is at the upper end of the depth guide groove. By the swing of the main body 306 around the axis 328, the amount (cut depth) of the lower portion of the saw blade 304 protruding from the lower surface of the base 302 is adjusted.

The motor 314 is a brushless motor, and includes a stator 360 and a rotor 362 arranged on the outer peripheral side (outer rotor).
The stator 360 has a plurality of (three-phase) stator windings 364, 364,... And their holders (stator cores) 366. The holder 366 has a cylindrical shape whose axis is in the left-right direction.
The rotor 362 includes a cup-shaped rotor body 370 having a bottom on the left, and a plurality of magnets (permanent magnets) 372, 372,... The motor shaft 321 is integrally fixed to the center of the bottom of the rotor body 370. The motor shaft 321 passes through a hole in the left and right direction of the holder 366 of the stator 360 and reaches inside the blade case 318. The right portion of the motor shaft 321 is rotatably supported by a right bearing 374, and the left portion of the motor shaft 321 is rotatably supported by a left bearing 376. The right bearing 374 is held by the blade case 318 via a bearing holder 378, and the left bearing 376 is held inside the left end of the motor housing 316 (between the ribs set up). Further, each magnet 372 faces one of the stator windings 364 of the stator 360.

A planetary gear mechanism 380 is disposed on the left (bottom of the cup) or left side of the rotor body 370. The planetary gear mechanism 380 includes an internal gear 382 having internal teeth, a plurality of (two) planetary gears 384 and 384 that mesh with the internal gear 382, and a pin 386 that rotatably supports each planetary gear 384. I have.
The internal gear 382 is attached to the motor housing 316.
The pins 386 are integrally fixed to the left portion of the rotor body 370 at positions facing each other (up and down in the figure). Each pin 386 protrudes leftward from the left portion of rotor body 370, and a corresponding planetary gear 384 is supported at the protruding portion.

On the left side of the planetary gear mechanism 380, a centrifugal fan 390 is arranged.
The centrifugal fan 390 has a blade portion 392 having a plurality of blades, and a gear portion 394 which is smaller in diameter than the blade portion 392, has a cylindrical shape coaxial with the blade portion 392, and is disposed on the right side of the blade portion 392.
On the outer curved surface of the gear portion 394, external teeth that mesh with each planetary gear 384 are formed.
Further, a fan bearing 396 is arranged in the blade portion 392. The fan bearing 396 has an outer ring integrally fixed to the centrifugal fan 390 and an inner ring integrally fixed to the motor shaft 321. Therefore, the centrifugal fan 390 can rotate relative to the motor shaft 321.
Exhaust ports 316a are formed in a portion of the motor housing 316 located outside the centrifugal fan 390 (blade section 392).
On the other hand, intake ports 319a, 319a,... Are opened in a part of the flange portion of the bearing retainer 319.

An operation example of such a circular saw 301 will be described.
When the main body 306 is fixed by the front fixing mechanism 330 or the rear fixing mechanism 340 and a switch (not shown) is turned on, the motor 314 is driven and the rotor 362 is rotated.
The saw blade 304 is rotated by the rotation of the motor shaft 321, and the work material can be cut by applying the saw blade 304 to the work material below the lower surface of the base 302. The safety cover 324 is sequentially housed in the blade case 318 by cutting the workpiece. By operating the lever 325 of the safety cover 324, the safety cover 324 can be manually housed in the blade case 318, and the replacement of the saw blade 304 is facilitated.
In addition, by operating the front fixing mechanism 330 in advance and fixing the main body 306 around the front-rear direction by tilting it to the left from the state shown in the figure, the saw blade 304 can be slanted such that the upper part is left and the lower part is right from a vertical state. , And it is possible to cut a workpiece in accordance with a non-vertical diagonal cut surface.
Further, by operating the rear fixing mechanism 340 in advance and fixing the main body 306 by tilting the main body 306 upward or forward around the left-right direction, the cutting depth with respect to the workpiece is adjusted.
The adjustment of the cutting depth is not performed when the main body 306 is tilted to the left via the front fixing mechanism 330 because the depth guide 332 is tilted together around the shaft portion 338. It is done in the same way.

In addition, the rotation of the rotor body 370 causes the centrifugal fan 390 to rotate via the planetary gear mechanism 380.
That is, the pins 386 and 386 revolve together with the rotor body 370, and the planetary gears 384 rotate around the pins 386 and 386, and run on the internal gear 382. Then, the gear portion 394 of the centrifugal fan 390 meshing with the planetary gears 384, 384 rotates at an increased speed.
Air is exhausted from the exhaust ports 316a, 316a,... By the blade portions 392 of the centrifugal fan 390, and air flows from the intake ports 319a, 319a,... To the exhaust ports 316a, 316a,. (See arrow W). The internal mechanism of the circular saw 301 including the motor 314 is cooled by the flow of air.

The above circular saw 301 includes a motor 314 having a motor shaft 321, a planetary gear mechanism 380 for increasing the rotation of the motor shaft 314, and a centrifugal fan 390 connected to the planetary gear mechanism 380. Therefore, the rotation speed of the centrifugal fan 390 can be increased with respect to the rotation speed of the motor shaft 321, the efficiency of cooling by the centrifugal fan 390 can be improved, and the temperature of the motor 321 can be increased due to abnormal temperature rise or maintenance of the state. Damage can be prevented. In particular, the circular saw 301 is more suitable for low-rotation and high-torque than the screw fastening tool such as the impact driver 1 because of the load characteristics when cutting the workpiece with the rotary blade. Even if employed, the centrifugal fan 390 can be rotated at a high speed by increasing the speed, and insufficient cooling can be avoided.
Further, since the speed increasing mechanism is the planetary gear mechanism 380 having the planetary gears 384 and 384, even if the motor shaft 321 and the axis of the centrifugal fan 390 are in the same direction, it is possible to simply increase the speed. Can be made compact.
Further, the motor 314 has a stator 360 and a rotor 362 disposed on the outer periphery thereof. Therefore, the motor 314 can be of an outer rotor type that is suitable for lower rotation and higher torque than the inner rotor type, and the required torque can be obtained without increasing the size of the motor 314 as compared with the inner rotor type. And the motor 314 can be made lightweight and compact, and the saw blade 301 can be made easy to handle.
In addition, since the saw blade 304 is attached to the motor shaft 321, the motor 314 can directly drive the saw blade 304, and the processing efficiency is improved.
Note that the centrifugal fan 390 and the planetary gear mechanism 380 are disposed at an axial end (left end) of the motor shaft 321. Therefore, the centrifugal fan 390 to be increased in speed is arranged outside the main mechanism, so that the circular saw 301 can be made compact and easy to handle.

Note that the third embodiment appropriately has the same modification as the first embodiment or the second embodiment.
In particular, a bevel gear mechanism may be employed as the speed increasing mechanism instead of the planetary gear mechanism. Further, a plurality of fans may be provided.
Further, the motor shaft may be oriented in the front-rear direction.
A rotary cutting tool other than a saw blade or another tip tool may be attached. One or more output shafts (intermediate shafts) may be interposed between the motor shaft and the tool bit.

[Fourth embodiment]
FIG. 15 is a perspective view of a caulking gun 401 as an electric filling tool according to a fourth embodiment of the present invention, FIG. 16 is a central longitudinal sectional view of FIG. 15, and FIG. FIG. 18 is a sectional view taken along line GG of FIG. 16, FIG. 19 is a sectional view taken along line HH of FIG. 16, FIG. 20 is a sectional view taken along line II of FIG. 17 is a sectional view taken along the line JJ in FIG. 17, and FIG. 22 is a sectional view taken along the line KK in FIG.
The caulking gun 401 is for setting a cartridge (not shown) containing a caulking agent and extruding the caulking agent toward gaps in the outer wall of the house, joints in the bathroom wall, and the like. A typical example of the caulking agent is a silicon-based filler.
The caulking gun 401 includes a motor housing 404 that accommodates a motor 402 and a power transmission mechanism 403 as a driving source in an upper portion, and a cartridge holder 405 that projects forward from an upper front side of the motor housing 404.

The motor housing 404 has half left and right portions connected via screw bosses 406, 406,... And screws 407, 407,... The lower part of the handle part 408 is formed as a battery mounting part 410 for mounting the battery 409.
A terminal block 412 on which a terminal plate 411 is mounted is provided in the battery mounting section 410. The battery 409 is mounted by sliding the battery 409 from the front side to the battery mounting portion 410. At this time, the slide rails 413 provided on the left and right of the upper part of the battery 409 enter along the left and right guide rails (not shown) in the battery mounting part 410. When the battery 409 is mounted on the battery mounting portion 410, the terminal plate 411 of the terminal block 412 is connected to a connection terminal (not shown) on the battery 409.
Above the terminal block 412, a controller 414 having a control circuit board on which a microcomputer for controlling the motor 402, a capacitor, and a plurality (six) of switching elements are mounted. An LED 415 as a light is connected to the controller 414. The LED 415 is disposed inside the front end of the battery mounting portion 410 so as to face diagonally upward (in a direction toward the front end side of the holder 405). A lens 416 perpendicular to the direction of the LED 415 is disposed in front of the LED 415. The lens 416 is fitted in a hole of the motor housing 404.
On the other hand, a sub-controller 419 including a circuit board on which a speed adjusting dial 417 and an LED 418 serving as an overload warning lamp are mounted is provided in an upper end portion of the motor housing 404. The rear portion of the speed adjustment dial 417 is exposed from a window 420 provided on the rear surface of the upper end portion of the motor housing 404. The LED 418 is oriented upward, and a bottomed cylindrical lens 421 is arranged above the LED 418 so as to cover the LED 418. The lens 421 is fitted into a boss formed on the upper surface of the motor housing 404. The lighting state of the LED 418 is visible to the operator via the lens 421.
A trigger 423 projecting from the switch 422 is exposed at the upper front side of the handle 408. Above the switch 422, a lock lever 424 that locks the trigger 423 from being pushed is provided.
The switch 422, the terminal block 412, and the sub-controller 419 are connected to the controller 414 by lead wires (not shown).
A gear housing 425 is arranged inside the motor housing 404 and outside (a part of) the power transmission mechanism 403. The gear housing 425 holds the power transmission mechanism 403.
The front end of the gear housing 425 protrudes forward from the upper front portion of the motor housing 404, and a cup-shaped holder joint 426 having a hole at the bottom is provided outside the protruding portion. The front surface of the bottom of the holder joint 426 is in contact with the rear surface of a plate 427 that expands vertically and horizontally. The plate 427 is fixed to the gear housing 425 by screws 428, 428.

The holder 405 has a semi-cylindrical shape whose axial direction is the front-rear direction and has a cylindrical surface at the bottom, and can be set by receiving the cartridge from below.
The rear end of the holder 405 is located in the holder joint 426 of the motor housing 404. The holder 405 is screwed to the holder joint 426, and the holder joint 426 is loosened from the motor housing 404. It is possible to remove it. The housing of the caulking gun 401 includes a motor housing 404, a holder 405, and a gear housing 425.
In the holder 405, an extruding rod 429 as output means extending in the front-rear direction so as to be movable in the front-rear direction is arranged. The push rod 429 is arranged below the sub-controller 419.

The motor 402 is a brushless motor, and is arranged behind the power transmission mechanism 403.
The motor 402 includes a stator 430 and a rotor 431 arranged outside the stator 430 (outer rotor).

The stator 430 includes a plurality of (three-phase) coils 432, 432,..., A stator core 433, and a coil holding part 434.
The stator core 433 is a cylindrical member whose axis is in the left-right direction, and is fixed in the rotational direction by being pressed into a rib provided in the motor housing 404.
The coil holding portion 434 has a shape in which a plurality of (12) teeth radially protrude from a cylindrical portion whose axis is in the left-right direction. By pressing the cylindrical portion of the coil holding portion 434 into the stator core 433, the coil holding portion 434 is fixed to the stator core 433 outside the stator core 433. In addition, the coils 432 are respectively arranged between the plurality of teeth of the coil holding section 434.

The rotor 431 includes a rotor main body 435 as a motor shaft arranged in a cup shape with a bottom portion on the right, and a plurality of magnets (permanent magnets) 436, 436... Having. On the left side of the magnets 436, 436,..., A sensor circuit board 438 on which a rotation detecting element 437 such as a Hall element is mounted is arranged. The sensor circuit board 438 is fixed by inserting a screw 441 into each of the bosses 440, 440 provided inside the motor housing 404.
The rotor center shaft 446 is integrally fixed with the center axis of the rotor and the center axis of the rotor body 435 aligned with the center of the rotor body 435 protruding left and right from the center of the bottom of the rotor body 435. The rotor center axis 446 passes through a hole in the left and right direction of the stator core 433 of the stator 430. The left end of the rotor center shaft 446 is rotatably supported by a left bearing 447, and the right end of the rotor center shaft 446 is rotatably supported by a right bearing 448. The left bearing 447 is held between the left end of the stator core 433 and the inner wall of the motor housing 404, and the right bearing 448 is held in the right portion of the motor housing 316 (between the ribs standing up). Each magnet 436 faces one of the coils 432 of the stator 430. The stator core 433 is arranged outside the rotor center shaft 446.
An output gear 449 is formed on the outer peripheral surface at the bottom of the rotor body 435. The output gear 449 is formed at a position that does not overlap with the magnets 436, 436,... Of the rotor 431 in the axial direction of the rotor center shaft 446.
Although not shown, the controller 414 and the coils 432, 432,... Are connected to each other by a lead wire without passing through the sensor circuit board 438. The terminal plate 411 and the controller 414 are connected to each other by a lead wire.

A planetary gear mechanism 450 is disposed on the left side (bottom of the cup shape) or the left side of the rotor body 435. The planetary gear mechanism 450 includes an internal gear 452 having internal teeth, a plurality (three) of planetary gears 454, 454,... Meshing with the internal gear 452, and a pin 456 for rotatably supporting each of the planetary gears 454. Have.
The internal gear 452 is attached to the motor housing 404.
The pins 456 are integrally fixed to the left part of the rotor main body 435 at positions at equal intervals in the circumferential direction. Each pin 456 protrudes leftward from the left part of the rotor main body 435, and the corresponding planetary gear 454 is supported at the protruding part.

An axial fan 460 is arranged on the left side of the planetary gear mechanism 450.
The axial fan 460 includes a blade portion 462 having a plurality of blades, and a gear portion 464 which is smaller in diameter than the blade portion 462, has a cylindrical shape coaxial with the blade portion 462, and is disposed on the right side of the blade portion 462. .
On the outer curved surface of the gear portion 464, external teeth that mesh with the respective planetary gears 454 are formed.
Further, a fan bearing 466 is arranged in the blade portion 462. The fan 466 allows the axial fan 460 to rotate relative to the rotor center axis 446.
An intake port (not shown) is formed in a portion of the motor housing 404 located on the left side of the axial fan 460, and a portion of the motor housing 404 located on the right side (outside the blade portion 462) of the axial fan 460. Has an exhaust port (not shown).

The power transmission mechanism 403 has a rotating shaft 470, a first carrier 472, a second carrier 474, and an output cylinder 476 as an output shaft.
The rotating shaft 470 extends in the left-right direction, and its left end is rotatably supported by a left bearing 480, and its right end is rotatably supported by a right bearing 482. The left bearing 480 and the right bearing 482 are fixed to (the boss provided on the inner wall of) the motor housing 404. The rotating shaft 470 has a driven gear 484 having a larger diameter at the right part than other parts. On the outer surface of the driven gear 484, teeth that mesh with the teeth of the output gear 449 of the rotor main body 435 of the motor 402 are formed.
The first carrier 472 includes a cylindrical portion 486 and a flange portion 488 formed at the left end thereof. The cross section of the cylindrical portion 486 has a polygonal shape with a plurality of (9) flat surfaces formed on the outer periphery. The cylindrical portion 486 is connected to the rotation shaft 470 outside the left portion of the rotation shaft 470.
The second carrier 474 is arranged outside the first carrier 472, and has a ring-shaped inner flange 490 overlapping the right surface of the flange 488 of the first carrier 472, and from the right surface of the inner flange 490 to the right. Are provided with a plurality of (9) support rods 492, 492,. The inner flange portion 490 is engaged with the flange portion 488 of the first carrier 472 so as to be relatively rotatable by a predetermined distance in the circumferential direction. The support rods 492, 492,... Are arranged concentrically at equal intervals in the circumferential direction. A plurality of (nine) cylindrical pins 494 are provided between each support rod 492.
The output cylinder 476 is a multi-stage cylinder having a central axis in the left-right direction, and has a small-diameter portion 496 and a large-diameter portion 498 disposed on the left side thereof. A right bearing 500 is provided outside the right end of the small diameter portion 496, and a left bearing 502 is provided outside the left end of the large diameter portion 498, so that the output shaft 476 can rotate around the central axis. Supported. The right bearing 500 and the left bearing 502 are mounted on the inner surface of the gear housing 425. A gear portion 504 is formed on the outer periphery of the small diameter portion 496. The left part of the rotating shaft 470 is arranged inside the small diameter part 496, and the support rods 492 and the pins 494 of the second carrier 474 are arranged inside the large diameter part 498.

In the power transmission mechanism 403, the power transmission state switches as follows (transmission state switching mechanism).
That is, when the rotation shaft 470 is not rotating forward (rotation in the rotation direction (forward direction) generated by transmission of the driving force of the motor 402), each pin 494 is on the flat surface of the cylindrical portion 486 of the first carrier 472. And the first carrier 472 and the output cylinder 476 are not integrated in the rotation direction without interfering with the large diameter portion 498 of the output cylinder 476, and the output cylinder 476 is in a rotation free state.
On the other hand, when the rotation shaft 470 rotates forward, the pins 494 are pushed up in the radial direction between the support rods 492 and 492 of the second carrier 474 by the movement of the flat surface of the cylindrical portion 486 accompanying the rotation of the first carrier 472. As a result, the torque from the first carrier 472 is transmitted to the output cylinder 476 via the respective pins 494, so that the gear 504 rotates forward.

Below the large diameter portion 498 of the output cylinder 476, a magnet 510 and a coil spring 512 as an elastic body are provided.
The magnet 510 is held in a vertical through hole 514 provided in the gear housing 425.
The coil spring 514 is vertically oriented, has an upper end in contact with the magnet 510, and a lower end in contact with a receiving seat 516 provided in the motor housing 404. The coil spring 514 presses the magnet 510 against the large-diameter portion 498, and the magnet 510 applies rotational resistance to the output cylinder 476. By providing the rotational resistance, switching between transmission and interruption of torque is performed more accurately.
A disk-shaped plate 520 having a hole is provided between the large diameter portion 498 of the output cylinder 476 and the inner flange portion 490 of the second carrier 474. The plate 520 positions the output tube 476 and blocks the contact with the inner flange portion 490.
A washer 524 is coupled to the constricted portion 522 at the left end of the rotating shaft 470. A dish-shaped spacer 526 is provided outside the flange portion 488 of the first carrier 472 and the inner flange portion 490 of the second carrier 474. Spacer 526 is attached to gear housing 425 and is located between plate 520 and washer 524. The outer periphery of the right surface of the spacer 526 is in contact with the left surface of the plate 520, and the spacer 526 positions the plate 520. Inside the spacer 526, a ring-shaped oil seal 528 that blocks oil by contacting the second carrier 474 (the outer surface of the inner flange portion 490) is provided.

The push rod 429 includes a rack 530 on the lower side. The rack 530 meshes with the gear 504 of the output cylinder 476. The rotation of the gear 504 is transmitted to the rack 530, and moves the push rod 429 forward and backward.
The push rod 429 has a disk-shaped piston 532 at the tip. The piston 532 is fixed to the tip of the push rod 429 by a screw 534.
Further, the push rod 429 includes an operation handle 538 extending left and right at the rear end.
The push rod 429 penetrates the gear housing 425 and the motor housing 404 from the holder 405, and the rear part thereof can be exposed to the rear of the motor housing 404.

An operation example of such a caulking gun 401 will be described.
When the motor 402 is not driven, the rotation of the output cylinder 476 becomes free, and the operator holds the operation handle 538 to retreat the push rod 429 so that the cartridge of the caulking agent is moved between the piston 532 and the tip of the holder 405. Can be set.
Then, the push rod 429 is moved forward to bring the piston 532 into contact with the rear end of the cartridge. In this state, when the operator pushes the trigger 423, the switch 422 is turned on, and the power of the battery 409 is reduced by the controller 414 and the sub-switch. In accordance with the control of the controller 419, the rotor 431 rotates by being supplied to each coil 432 of the stator 430 of the motor 402. The controller 414 switches the switching element based on the received detection signal of the rotation detection element 437, and sequentially energizes the coils 432, 432,.

When the rotor 431 rotates, the axial fan 460 operates via the planetary gear mechanism 450.
That is, the planetary gears 454, 45... Rotate (revolve and rotate) in the internal gear 452 via the pins 456, 456,... Together with the rotor main body 435, and rotate the axial fan 460 through the gear portion 464. The axial fan 460 rotates at a speed increased by the planetary gear mechanism 450 with respect to the rotation of the rotor main body 435.
The axial fan 460 sucks air from an intake port of the motor housing 404 and discharges it from an exhaust port to generate a flow of air from the intake port to the exhaust port. The air passes between the stator 430 and the rotor 431, and the motor 402 is cooled.

When the rotor 431 rotates, the rotation is transmitted to the rotation shaft 470 of the power transmission mechanism 403 through the output gear 449 or the driven gear 484, and the first carrier 472 integrated with the rotation shaft 470 rotates forward, and the wedges of the pins 494 are rotated. The output cylinder 476 subjected to the action rotates integrally.
When the output shaft 476 rotates, the push rod 429 moves forward through the gear portion 504 or the rack 530, and pushes the rear end of the cartridge through the piston 532. The caulking agent is discharged from the front end of the cartridge whose rear end is pressed. The moving speed of the push rod 429 can be adjusted by a speed adjusting dial 417.

  When the operator stops pushing the trigger 423, the switch 422 is turned off. At the moment when the switch 422 is turned off, the controller 414 slightly rotates the rotor 431 of the motor 402 in reverse (rotation in the direction opposite to the normal direction), and stops the operation of the motor 402. By this reverse rotation, the wedge action of each pin 494 is released, and the output cylinder 476 enters a rotation free state.

Such a caulking gun 401 includes a motor 402 having a rotor body 435, a planetary gear mechanism 450 for increasing the rotation of the rotor body 435, and an axial fan 460 connected to the planetary gear mechanism 450. Therefore, the rotation speed of the axial fan 460 can be increased with respect to the rotation speed of the rotor body 435, the cooling efficiency of the axial fan 460 can be improved, and the motor can be abnormally raised in temperature or maintained by maintaining the state. 402 can be prevented from being damaged.
Further, the motor 402 has a stator 430 and a rotor 431 arranged on the outer periphery thereof. Therefore, the motor 402 can be of an outer rotor type that is suitable for lower rotation and higher torque than the inner rotor type, without increasing the size of the motor 402 and the power transmission mechanism 403 as compared with the inner rotor type. However, the required torque can be secured, the motor 402 and the power transmission mechanism 403 can be made lightweight and compact, and the caulking gun 401 can be made easy to handle.

Note that the above-described fourth embodiment appropriately has the same modified example as the first to third embodiments.
For example, the handle portion of the motor housing may be a separate handle housing, or the motor housing and the gear housing may be integrally formed.
Further, the stator core and the coil holding portion of the motor may be fixed by spline connection or screw connection instead of press fitting. The arrangement of the motor controller, the sub-controller, and the sensor circuit board may be changed, and the mounting elements and the like in these may be changed such that the switching element is arranged on the sensor circuit board. Alternatively, a motor other than a brushless motor such as an inner rotor type motor or a brushed motor may be used.
Further, the driven gear and another part of the rotating shaft may be formed separately.
A plurality of types of holders may be prepared so that they can be replaced according to the type of the cartridge.
The directions of the motor and the power transmission mechanism may be reversed left and right, or their positions may be changed.
The number of rotating shafts of the power transmission mechanism may be increased, or a planetary gear mechanism may be employed in the power transmission mechanism.
The motor need not be a direct drive motor. That is, the power of the motor may be decelerated and transmitted to the output shaft, or may be increased in speed and transmitted to the output shaft.

  1. Impact driver (electric power tool), 11,314,402 motor, 18 anvil (output shaft), 56,321 motor shaft, 72 planetary gear, 78,86,390 centrifugal Fan (fan), 79, 380, 450 planetary gear mechanism (speed increasing mechanism), 82 bevel gear, 89 bevel gear mechanism (speed increasing mechanism), 201 soft impact driver, 202 shaft (output) Shaft), 301 Marunoco, 304 Saw blade (tip tool), 360, 430 Stator (Inner stator), 362, 431 Rotor (Outer rotor), 401 Coking gun, 435 Rotor Main body (motor shaft), 460 ··· Axial fan (fan), 476 ··· Output cylinder (output shaft).

Claims (5)

A motor having a motor shaft;
A first speed increasing mechanism for increasing the rotation of the motor shaft;
A first fan connected to the speed increasing mechanism ;
A housing for holding the motor;
Equipped with a,
The first speed increasing mechanism and the first fan are arranged in the housing so as to be coaxial with the motor shaft,
The power tool according to claim 1, wherein the first fan cools the motor. Further, an output shaft driven by the motor shaft is provided,
The motor shaft is oriented in the front-rear direction,
The first fan is a centrifugal fan,
The output shaft is disposed in front of the motor shaft,
The first speed-increasing mechanism, Ri planetary gear mechanism der having a planetary gear,
The first speed increasing mechanism and the first fan are disposed at a rear end of a motor shaft.
The power tool according to claim 1, wherein: Further, a second speed increasing mechanism for increasing the rotation of the motor shaft, and a second fan connected to the second speed increasing mechanism,
The second speed-increasing mechanism, Ri bevel gear mechanism der having a bevel gear,
The second fan is a centrifugal fan,
The second speed increasing mechanism and the second fan are disposed at a front end of a motor shaft.
The power tool according to claim 2, wherein: The motor, power tool according to claim 1 or claim 3, characterized in that it comprises a stator, a rotor disposed on the outer periphery thereof, a. The power tool according to claim 2 , wherein a tip tool is attached to the output shaft.

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