JP2018202511A - Electric tool - Google Patents

Abstract

To provide an electric tool which achieves arrangement of a speed adjustment mechanism which does not impair workability.SOLUTION: An electric tool has: a motor having a rotary shaft; a housing which houses the motor; a holding part which is provided at the housing, extends in a rotation axis direction, and can be gripped by a worker; a diameter expansion part which is provided at the housing, is connected to the holding part, and has a diameter larger than the holding part; a battery which supplies electric power to the motor; a battery attachment part which is provided at the diameter expansion part and extends in a direction intersecting with the rotation axis direction and to which the battery may be attached; and a control part which controls the motor. The control part is housed in the diameter expansion part. A speed adjustment mechanism which can be operated by the worker is disposed between the control part and the battery.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power tool such as a grinder.

  The electric tool generally includes a motor that drives a rotating tool, and performs various operations by rotating the tip tool with the motor. It is preferable that the rotational speed of the tip tool is arbitrarily changed according to the work mode and has a function to match the material to be processed. In the prior art document, a battery as a power source is attached to the rear of a housing that houses a motor, and a control unit that controls the motor in a diameter-enlarged portion that is formed as a battery mounting portion; There has been disclosed a grinder provided with a dial capable of adjusting the rotation speed.

JP, 2006-007680, A

  In the grinder of the prior art document, the dial is arranged near the outer periphery of the housing used as a gripping part (immediately rearward), so that the protrusion of the dial can be an obstacle to gripping the housing, and the dial is placed near the gripping part. Due to the arrangement, the dial may be accidentally touched even in a normal gripping state, and the motor speed may be changed even during work.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide an electric tool in which a speed adjustment mechanism of a motor is arranged at an appropriate location.

  One embodiment of the present invention is a power tool. The electric tool includes a motor having a rotation shaft, a housing that houses the motor, a grip portion that is provided in the housing and extends in the rotation shaft direction and can be gripped by an operator, and is provided in the housing. A diameter-enlarged portion that is connected to the gripping portion and has a larger diameter than the gripping portion, a battery that supplies electric power to the motor, and a battery that is provided in the diameter-expanded portion and extends in a direction intersecting the rotation axis direction. A battery mounting portion that can be mounted on the motor, and a control portion that controls the motor. The control portion is housed in the enlarged diameter portion, and a speed adjustment mechanism that can be operated by an operator is provided between the control portion and the battery. Place between.

  ADVANTAGE OF THE INVENTION According to this invention, the electric tool which does not impair workability | operativity is realizable.

It is a side view of the grinder 1 which concerns on the Example of this invention. It is a bottom view of the grinder 1 which concerns on the Example of this invention. It is sectional drawing of the grinder 1 which concerns on the Example of this invention. It is a side view of the 1st modification which implements the present invention. It is a side view of the 2nd modification which implements this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, the same portions are denoted by the same reference numerals, and repeated description is omitted. In the present invention, description will be made assuming that the front, rear, left, right, and up and down directions are directions shown in the drawing.

  FIG. 1 is a side view of a grinder 1 according to an embodiment of the present invention. FIG. 2 is a bottom view of the same. FIG. 3 is a sectional view of the same.

  The housing of the disc grinder 1 includes a housing 2 that houses a motor 11 (to be described later), a gear cover 3 that is attached to the front of the housing 2, and main parts of the packing land 4. The grinder 1 is provided with a battery holding part 22A at the rear of the housing 2, and the battery provided in the battery holding part 22A is inserted by sliding the battery 22 on a rail (not shown) provided in the battery holding part 22A. The terminal of the terminal 29 and the battery 22 are engaged, and electric power is supplied into the housing 2.

  A motor 11 is accommodated in the housing 2. The motor 11 is, for example, a brushless DC motor. The gear cover 3 accommodates a power transmission mechanism including two sets of bevel gears for converting the direction of power transmission by the rotating shaft 12 of the motor by about 90 degrees, that is, a first bevel gear 13 and a second bevel gear 14. It is fixed to the housing 2 with four screws 32 inserted from the front side in the axial direction to the rear side. A handle attachment hole 31 for attaching a side handle (not shown) is formed on the side surface of the gear cover 3. Further, an exhaust port 24 for discharging cooling air is provided above the gear cover 3. A spindle lock 20 is provided on the front side of the exhaust hole 24. The spindle lock 20 is a mechanism that locks the spindle 7 so as not to rotate when the tip tool such as the grindstone 8 is attached or detached. When the upper part of the spindle lock 20 is pressed, a lock pin (not shown) The spindle 7 becomes non-rotatable by protruding and fitting into a recess (not shown).

  A spindle 7 extends downward from the gear cover 3, and a grindstone 8 as a tip tool is attached to the tip (lower end) of the spindle 7. The grindstone 8 can be attached to and detached from the spindle 7 by fixtures 9a and 9b. The grindstone 8 is, for example, a flexible toy, a resinoid toy, a sanding disk, or the like having a diameter of 100 mm, and surface polishing or curved surface polishing of metal, synthetic resin, marble, concrete, or the like is possible by selecting an abrasive to be mounted. The rotational speed of the grindstone 8 is, for example, about 3,000 to 10,000 rpm, and may be appropriately set according to the work target by operating the dial 30 described later. The wheel guard 21 is for protecting an operator from scattering of a ground member or damaged abrasive grains, and is fixed to the packing land 4.

  The packing land 4 holds a later-described bearing 19 that holds the spindle 7, and is attached to the lower side of the gear cover 3.

  As the motor 11, a brushless DC motor is used in this embodiment, but a DC motor with a brush may be used. The motor 11 is disposed so as to be accommodated in the housing 2, and the rotation shaft 12 of the motor 11 is disposed so as to coincide with the axial direction (front-rear direction) of the cylindrical housing 2. The shape of the housing 2 is preferably a cylindrical shape or a long cylindrical shape because it can be strengthened in strength.

  The rotating shaft 12 of the motor 11 is rotatably held by a bearing 17 fixed to the gear cover 3 and a bearing 16 fixed near the inner center of the housing 2. A cooling fan 15 is provided on the front side of the rotating shaft 12 and the motor 11. The cooling fan 15 is a plastic centrifugal fan, for example. The cooling fan 15 sucks outside air from an intake hole 23 provided in the enlarged diameter portion 2e of the housing 2 to be described later, generates an air flow that passes through the motor 11, and Air is discharged forward from the exhaust hole 24 provided. In addition, a filter 10 is provided in the air intake hole 23 to prevent foreign matter such as cutting powder and small gravel from entering the housing 2.

  The rotating shaft 12 is rotatably held by a ball-type bearing, and a first bevel gear 13 is attached to the tip of the rotating shaft 12. The first bevel gear 13 meshes with the second bevel gear 14 attached to the spindle 7. In this embodiment, the number of teeth of the first bevel gear 13 is sufficiently smaller than the number of teeth of the second bevel gear 14, and the first bevel gear 13 and the second bevel gear 14 serve as a speed reduction mechanism.

  The spindle 7 is rotatably held on the upper side by a needle bearing 18 that is a first bearing, and the lower side is rotatably held on a bearing 19 that is a second bearing. Here, the needle bearing 18 is fixed to the gear cover 3 side, and the bearing 19 is fixed to the packing land 4 side.

  The housing 2 is a split-type housing in which split pieces are combined, and is formed by matching the left housing 2a and the right housing 2b on a virtual plane extending vertically and horizontally. The housing 2 has a front large diameter portion 2c and a rear small diameter portion 2d, both of which can be used as a gripping portion. A slide type operation unit 6 is provided on the side wall of the large diameter part 2c, and a switch 27 is provided on the small diameter part 2d. The operation unit 6 and the switch 27 are connected by a slide bar 28, and the switch 27 can be turned on by transmitting the movement of the operation unit 6 to the switch 27. That is, the operator can drive the motor 11 by operating the switch 6 while gripping the outer periphery of the housing 2.

  An enlarged diameter portion 2 e is provided at the rear portion of the housing 2. The control part 25, the terminal 29, and the dial 30 are accommodated in the enlarged diameter part 2e. The dial 30 is configured to be rotatable about an axis extending in a direction intersecting with the rotation shaft 12 (a direction substantially orthogonal to the extending direction of the battery holding portion 22A). Air inlets 23 are provided on the left and right side walls of the enlarged diameter portion 2e. The rear portion of the enlarged diameter portion 2e is a battery holding portion 22A. The battery holding portion 22A extends in a direction intersecting with the direction in which the rotating shaft 12 extends (the direction of the chain line L1 in the figure), and the battery holding portion 22A extends. The present direction is inclined so as to form an angle of about 60 ° with respect to the rotating shaft 12. The battery 22 can be attached and detached by sliding it in the direction of the chain line L1 with respect to the battery holding portion 22A. The battery 22 is provided with an attachment / detachment operation part 22B. In the attached state, the battery 22 can be detached from the housing 2 by operating the attachment / detachment operation part 22B.

  The control unit 25 is a case that accommodates a substrate on which a control circuit is mounted. The control unit 25 has a heat radiating member 26, and the heat radiating member 26 is arranged in the air flow path in the housing 2 to cool the control unit 25. It can be carried out. The heat dissipating member 26 is a metal member made of, for example, aluminum, and the large end heat dissipating member 26 can be efficiently accommodated by positioning the front end portion in the small diameter portion 2d of the housing 2.

  According to the present embodiment, since the control unit 25 is disposed between the grip portion (particularly the small diameter portion 2d) of the housing 2 and the dial 30, a distance from the grip portion to the dial 30, particularly a distance in the front-rear direction is ensured. It is possible to prevent the dial 30 from being erroneously operated while gripping the grip portion.

  In the present embodiment, the enlarged diameter portion 2 e is inclined with respect to the rotating shaft 12. Specifically, since the upper part of the enlarged diameter part 2e is inclined so that the upper part is positioned rearward and the lower part is located forward, the enlarged diameter part 2e is less likely to become an obstacle when grasping the gripping part from above. Workability can be improved for ease.

  Further, since the enlarged diameter portion 2e extends in a direction intersecting with the gripping axis of the gripping portion, the enlarged diameter portion 2e functions as a stopper (鍔) of the gripping portion, and the operator's hand can be shifted back and forth from the gripped state. Can be suppressed.

  Further, by providing the intake port 23 behind the control unit 25, the control unit 25 can be efficiently cooled by applying cooling air to the rear surface of the control.

  Further, regarding the area on the rear surface side of the control part 25 in the enlarged diameter part 2e, the upper part is an area for holding the attachment / detachment operation part 22B of the battery 22, and the lower part is an area for holding the dial 30 for speed adjustment. By using the space (in the middle) as a region for holding the terminal 29 and a region for forming the intake port 23, the rear side region of the control unit 25 can be used without waste, and the compact grinder 1 can be realized. Furthermore, in this embodiment, since the attaching / detaching operation portion 22B, the dial 30, the terminal 29, and the air inlet 23 are positioned on the straight line L1 intersecting with the extending direction of the rotating shaft 12, further useless space is eliminated. As a result, a compact grinder 1 was realized.

  Next, a modified example in which a change is made from the above-described embodiment will be described. FIG. 4 shows a grinder 101 as a first modification. Modification 1 is the same as the above-described embodiment except for the peripheral structure of the enlarged diameter portion 102e, and only the changes will be described below. Moreover, the same code | symbol is provided to the structure same as the Example mentioned above.

  In the first modification, the enlarged diameter portion 102e extends so as to be substantially perpendicular to the rotating shaft 12, the battery holding portion 122A also extends in a direction substantially perpendicular to the rotating shaft 12, and the control portion 125 is also included in the rotating shaft 12. It extends in a direction substantially perpendicular to the direction. The dial 130 is rotatable around an axis parallel to the rotary shaft 12, and is provided below the enlarged diameter portion 102e. As described above, in the first modification, the member accommodated in the enlarged diameter portion 102e is arranged so as to extend in a direction substantially perpendicular to the rotation shaft 112 as compared with the above-described embodiment. As a result, the rear portion of the enlarged diameter portion 102e, and hence the rear end of the battery 122, moves forward, so that in the first modification, it is possible to realize the grinder 101 whose overall length is compact compared to the above-described embodiment. Other effects are the same as in the above-described embodiment.

  Next, Modification 2 will be described. FIG. 5 shows a grinder 201 as a second modification.

  Modification 2 is the same as the above-described embodiment except for the peripheral structure of the enlarged diameter portion 202e, and only the changes will be described below. Moreover, the same code | symbol is provided to the structure same as the Example mentioned above.

  In the enlarged diameter portion 202e of the grinder 201, the battery holding portion 222A extends in a direction substantially perpendicular to the rotating shaft 12, and the control portion 225 intersects each of the extending directions of the rotating shaft 12 and the battery holding portion 222A. Extending in the direction. In the modified example 2, since the control unit 225 is inclined with respect to the battery holding unit 222A, a large space can be secured in the lower portion of the enlarged diameter portion 202e, and the dial 230 is disposed in the space. Since the space for arrangement is increased, the dial 230 can be made larger than the above-described embodiment, and the operability of the dial 230 can be improved. In the second modification, the size of the dial is increased to improve the operability of the speed adjustment mechanism. However, while the dial 230 is made the same size as the above-described embodiment, another operation member (for example, A button for displaying the remaining battery level can also be arranged. In this case, since a plurality of operation members can be collected in one place, workability can be improved.

  As mentioned above, although this invention was demonstrated along the Example and the modification, this invention has a battery and a control part in addition to the grinder which is an example, what has a speed adjustment mechanism which an operator can operate, for example, It can also be applied to jigsaws.

  In the embodiment of the present invention, the dial is used for adjusting the rotational speed of the tip tool, but it may be replaced with other operation means such as a tact switch.

1 grinder, 2 housing, 2a left housing, 2b right housing, 2c large diameter part, 2d small diameter part, 2e large diameter part, 3 gear cover, 4 packing land, 6 operation part, 7 spindle, 8 grindstone, 9a, 9b fixed Tool, 10 Filter, 11 Motor, 12 Rotating shaft, 13 First bevel gear, 14 Brother 2 bevel gear, 15 Cooling fan, 16 Bearing, 17 Bearing, 18 Needle bearing, 19 Bearing, 20 Spindle lock, 21 Wheel guard, 22 Battery, 23 Intake hole, 24 Exhaust hole, 25 Control part, 27 Switch, 28 Slide bar, 29 Terminal, 30 Dial, 31 Handle mounting hole, 32 Screw

Claims (5)

A motor having a rotating shaft;
A housing for housing the motor;
A grip portion provided in the housing and extending in the direction of the rotation axis and gripped by an operator;
Provided in the housing, connected to the gripping portion, and an enlarged diameter portion having a larger diameter than the gripping portion;
A battery for supplying power to the motor;
A battery mounting portion that is provided in the diameter-expanding portion and extends in a direction crossing the rotation axis direction, and the battery can be mounted;
A control unit for controlling the motor,
The control unit is accommodated in the enlarged diameter portion,
An electric tool characterized in that a speed adjustment mechanism that is operable by an operator and capable of adjusting a rotation speed of the motor is accommodated between the control unit and the battery. The diameter-expanded portion is larger in diameter than the grip portion in a direction intersecting the rotation axis direction,
The battery holding portion is provided with a terminal that is electrically connected to the battery and extends in a direction intersecting the rotating shaft,
The electric power tool according to claim 1, wherein the control unit extends in a direction intersecting with the rotation axis in the enlarged diameter portion. A gear case is attached to the housing,
The gear case is provided with an exhaust port,
A fan that is rotated by the motor is accommodated in the housing,
The enlarged-diameter portion is provided with an intake port for introducing air into the housing,
3. The electric tool according to claim 2, wherein the intake port and the speed adjustment mechanism are arranged between the control unit and the battery in a direction substantially perpendicular to the extending direction of the battery holding unit. . The power tool according to claim 3, wherein the speed adjustment mechanism and the air inlet are arranged side by side in the extending direction of the battery holding portion. The electric power tool according to any one of claims 1 to 4, wherein the speed adjustment mechanism is a dial that is rotatable about an axis in a direction substantially orthogonal to the extending direction of the battery holding portion. .