JP2001198855A - Power tool and motor for power tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce weight of a motor and to prevent grease or the like of the reduction gear side from penetrating the motor. SOLUTION: In this power tool, the motor 2 and the reduction gear 3 for reducing an output of the motor are serially arranged inside a cylindrical housing. The cylindrical housing is provided with an engagement protrusion part 18 in its inner surface, and the motor 2 is provided with an engagement recessed part 28 engaging with the engagement protrusion part 18 in an outer circumferential surface for fixing it inside the housing by the engagement of the engagement protrusion part 18 and the engagement recessed part 28. Fixation to the housing can be performed without fixing a motor mount by a screw on a surface of the motor 2 on the reduction gear 3 side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a power tool and a motor for the power tool.

[0002]

2. Description of the Related Art An electric tool such as an electric drill driver has a configuration in which a motor and a speed reducer for reducing the output of the motor are arranged in series in a cylindrical housing. In this case, FIG. As described above, the motor mount 32 is fixed to the distal end surface of the motor 2 with the screw 35, and the gear case 31 of the speed reducer 3 is connected to the motor mount 32, and the motor mount 32 is fixed.
Is fixed to the cylindrical housing with the fixing flange portion 34 provided on the housing and the fixing flange portion 33 of the gear case 31. In the drawing, reference numeral 9 denotes a fixing portion.

[0003]

In this case, the portion of the outer shell of the motor on which the motor mount is fixed, on the side of the speed reducer, must have strength. This is one of the factors that hinder the weight reduction of the motor. The holes provided in the motor mount for passing the screws increase the possibility that grease or the like inside the speed reducer may enter the motor side.

[0004] The present invention has been made in view of such a point, and it is an object of the present invention to reduce the weight of a motor and to cause grease or the like on a reduction gear side to enter the motor. It is an object of the present invention to provide a power tool without any problem, and to provide a motor for a power tool which does not cause a problem in terms of fixing and can be reduced in weight.

[0005]

According to the present invention, there is provided an electric tool in which a motor and a speed reducer for reducing the output of the motor are arranged in series in a cylindrical housing.
The cylindrical housing has an engagement protrusion on its inner surface, and the motor has an engagement recess on the outer surface on which the engagement protrusion engages, and the motor engages the engagement protrusion with the engagement recess. And is fixed in the housing. The motor can be fixed to the housing without fixing the motor mount to the surface of the motor on the side of the speed reducer.

[0006] It is further advantageous in terms of weight reduction that the motor has an engaging recess on the outer peripheral surface of a portion where a magnetic circuit forming member such as a magnet or an iron core is disposed.

[0007] The electric tool motor according to the present invention comprises:
A motor for an electric tool, wherein a case of an outer shell has a thick yoke on an outer peripheral portion thereof, and a magnetic circuit forming member such as a magnet or an iron core is arranged on an inner peripheral side of the yoke. It is characterized in that the engaging recess is formed on the outer surface of the yoke.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to an embodiment. An electric tool shown in FIG. 2 is an electric drill driver, and a motor 2 is provided in a cylindrical housing portion 10 of a main body 1 thereof. And a deceleration block 3, and a switch block 13 operated by a trigger handle 13 and a rotation direction switching lever 14 in a grip portion 11 extending from the middle of the cylindrical housing portion 10.
And a power cord 6 at the tip of the grip portion 11.
The AC adapter pack 6 from which the battery pack 1 is drawn out is detachable, and a battery pack (not shown) containing a secondary battery can be mounted in place of the AC adapter pack 6. .

When the battery pack is mounted, power is supplied to the motor 2 via the power supply fitting 15 and the switch block 13, and when the AC adapter pack 6 is mounted, the connectors 16, 60 and the switch block 13 are connected. The power is supplied to the motor 2 via the.

The AC adapter pack 6 has a built-in rectifying / smoothing circuit for an AC power supply and outputs high-voltage DC, and includes a low-voltage DC output from a battery pack.
In order to be able to drive the motor 2 with both of the high-voltage direct current, the motor 2 is provided with a rotor 23 having a multiplexed rotor winding 24 and one rotor winding. Brush rectifier 25 for supplying high-voltage DC
And a DC drive brush magnet motor having a brush rectifier 26 for supplying a low-voltage DC to the other rotor winding. The motor drive characteristics (rotational speed-torque characteristics) of the two types of rotor windings 24 are substantially equal. That is, since the no-load rotation speed is uniquely determined by the supply voltage V and the number of turns n of the rotor windings, it is made equal by adjusting the number of turns with both types of rotor windings. In the case of the pack, the balance between the internal resistance of the battery and the contact resistance of each part and the coil resistance is made equal, and in the case of the AC power supply, the balance between the contact resistance and the coil resistance of each part is made equal by adjusting the coil wire diameter and the like.

The outer shell of the motor 2 comprises a thick cylindrical yoke 21 located on the outer periphery of the rotor winding 24,
Thin bearing stands 22, 2 welded to both ends of the yoke 21, respectively.
The magnet 27 is fixed to the inner peripheral side of the yoke 21. A plurality of engagement recesses 28, 28 arranged in the axial direction are formed on the left and right sides of the outer surface of the yoke 21, respectively.

On the other hand, as shown in FIGS. 4 and 5, a plurality of engaging projections 1 arranged in the front-rear direction are provided on the inner surface of a cylindrical housing portion 10 formed by the left and right halves of the main body 1 of the power tool.
If the motor 2 is incorporated in the cylindrical housing portion 10, the engaging projections 18 engage the engaging recesses 28 of the motor 2 to fix the motor 2. .

For this reason, it is not necessary for the motor mounting base 32 to play the role of fixing the motor 2 to the main body 1, and even if the motor mounting base 32 is provided as shown in FIG. Need only have a role of centering the gear case 31 of the speed reducer 3 and the motor 2.
The outer shell of the motor 2 (the bearing stand 22) on the side of the reducer 3 is the main body 1
Since it is not involved in fixing to the motor, a thin and low-strength material may be used. Therefore, the weight of the motor 2 can be reduced, and it is not necessary to fix the motor mount 32 to the motor 2 with screws. This eliminates the need for a screw insertion hole that penetrates the motor mount 32, thereby reducing the risk of grease or the like in the speed reducer 3 entering the motor.

Further, in the illustrated motor 2, the motor 2
Of the outer shell components need to have a thickness from the point of view of the magnetic circuit, and accordingly, a portion having sufficient strength necessary for fixing the motor 2 in the axial and rotational directions is provided in the engaging recess 2.
Since the motor 8 is provided, fixing this portion to the main body 1 eventually promotes further reduction in the weight of the motor 2.

[0015]

As described above, in the electric power tool according to the present invention, the engaging projection provided on the inner surface of the cylindrical housing is engaged with the engaging recess provided on the outer peripheral surface of the motor and fixed in the housing. The motor can be fixed to the housing without fixing the motor mounting base to the surface of the motor on the side of the speed reducer, and the outer shell of the motor on the side of the speed reducer is accordingly fixed. It is not necessary to increase the strength of the motor, the weight of the motor can be reduced by reducing the thickness, and the possibility that grease or the like on the speed reducer side can enter the motor through holes for screwing can be eliminated.

At this time, it is more advantageous in terms of weight reduction if the motor is provided with an engagement concave portion on the outer peripheral surface of the portion where the magnetic circuit forming member such as the magnet or the iron core is arranged.

The motor for a power tool according to the present invention comprises:
A motor for an electric tool, wherein a case of an outer shell has a thick yoke on an outer peripheral portion thereof, and a magnetic circuit forming member such as a magnet or an iron core is disposed on an inner peripheral side of the yoke, and a fixing engagement is provided. A recess is formed on the outer surface of the yoke,
The part that must be thickened to satisfy the magnetic characteristics is used for fixing, so the part that originally has the strength required for motor fixing is fixed using the part that originally has the strength, and the engaging concave part is fixed. In some cases, a light-weight product can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a schematic configuration of an example of an embodiment of the present invention.

FIG. 2 is a cutaway side view showing the overall configuration of the same.

FIG. 3 is a cross-sectional view of the same motor.

FIG. 4 is a perspective view of a housing on one side.

FIG. 5 is a perspective view of another housing on one side.

FIG. 6 is a partial cross-sectional view showing an engagement portion.

FIG. 7 is an explanatory diagram showing a schematic configuration of a conventional example.

[Explanation of symbols]

 2 Motor 3 Reducer 9 Fixing part 18 Engagement protrusion 28 Engagement recess

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[Procedure amendment]

[Submission date] July 3, 2000 (2007.3)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0002

[Correction method] Change

[Correction contents]

[0002]

2. Description of the Related Art An electric tool such as an electric drill driver has a configuration in which a motor and a speed reducer for reducing the output of the motor are arranged in series in a cylindrical housing. In this case, FIG. As described above, the motor mount 32 is fixed to the distal end surface of the motor 2 with the screw 35, and the gear case 31 of the speed reducer 3 is connected to the motor mount 32, and the motor mount 32 is fixed.
And the fixing flange 33 of the gear case 31 are fixed to the cylindrical housing, and are fixed in the axial direction.
And the rotation direction is maintained . In the drawing, reference numeral 9 denotes a fixing portion.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction contents]

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to an embodiment. An electric tool shown in FIG. 2 is an electric drill driver, and a motor 2 is provided in a cylindrical housing portion 10 of a main body 1 thereof. And a deceleration block 3, and a switch block 13 operated by a trigger handle 12 and a rotation direction switching lever 14 in a grip portion 11 extending from the middle of the cylindrical housing portion 10.
And a power cord 6 at the tip of the grip portion 11.
The AC adapter pack 6 from which the battery pack 1 is drawn out is detachable, and a battery pack (not shown) containing a secondary battery can be mounted in place of the AC adapter pack 6. .

[Procedure amendment 3]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

FIG. 2

Claims (3)

[Claims] 1. An electric tool in which a motor and a speed reducer for reducing the output of the motor are arranged in series in a cylindrical housing, wherein the cylindrical housing has an engagement projection on its inner surface. An electric power tool characterized in that the outer peripheral surface is provided with an engaging concave portion with which the engaging protrusion engages, and the electric tool is fixed in the housing by the engagement between the engaging protrusion and the engaging concave portion. 2. The electric tool according to claim 1, wherein the motor has an engagement recess on an outer peripheral surface of a portion where a magnetic circuit forming member such as a magnet or an iron core is arranged. 3. A motor for an electric tool, wherein a case of an outer shell has a thick yoke on an outer peripheral portion thereof, and a magnetic circuit forming member such as a magnet or an iron core is arranged on an inner peripheral side of the yoke. A motor for a power tool, wherein an engaging recess for fixing is formed on an outer surface of the yoke.