JP4655655B2 - Electric tool - Google Patents

Description

  The present invention relates to an electric tool including a handle portion provided so as to protrude from a housing that houses a motor.

  Patent Document 1 discloses the following electric tool. That is, a handle 26 made of an insulating material such as resin is fixed to the motor housing 14 made of aluminum, and the switch means 34 is accommodated in the handle 26. A cylindrical sleeve 86 made of an insulating material such as a resin is provided between the motor 34 and the motor housing 14, and a back cap 22 made of an insulating material such as a resin is fixed to the rear of the motor housing 14. Yes. In addition, some parts are formed of an insulating material and used in combination with the sleeve 86 and the back cap 22. The switch means 34 and the motor 34 are also insulated and have a double insulation structure.

  The following electric tools are disclosed in FIGS. 9 to 13 of Patent Document 2. That is, the insulating piece 12 a is incorporated into the inner surface of the housing 1 made of a conductive material such as aluminum that houses the motor 2, and the insulating block 12 b is incorporated behind the housing 1. The motor 2 itself is also insulated and has a double insulation structure.

U.S. Pat. No. 3,344,291 JP 2003-231071 A

  In the electric tool described in Patent Document 1, the handle 26 is fixed to the motor housing 14, but the fixing means is not described. Although it is estimated from the drawing that the fixing is performed by using a fixing means such as a screw, in any case, the connection between the handle 26 and the motor housing 14 is made by local engagement or fastening. When an impact is applied, stress concentrates on the connecting portion between the handle 26 and the motor housing 14, and the connecting portion is likely to be damaged. In addition, the rigidity of the connecting portion is low, causing sag during work and poor operability. In addition, at least three parts, ie, the handle 26, the sleeve 86, and the back cap 22, are necessary for insulation, and the manufacturing cost is high.

  In the electric tool described in Patent Document 2, there is no description about the handle. The parts required for insulation require at least two of the insulation piece 12a and the insulation block 12b, and the manufacturing cost is high.

  An object of the present invention is to solve the above-described problems and to provide a power tool that is safe, strong, and easy to operate at low cost.

  The present invention relates to a motor having an armature and a stator, a resin stator holder that supports the outer periphery of the stator, a metal housing that is an outer frame that supports the outer periphery of the stator holder, and an adjacent to the housing. In an electric tool comprising: a gear case that is an outer frame provided by the motor; a reduction mechanism that is housed in the gear case and transmits the rotational force of the motor; and a switch that controls power supply to the motor. One feature is that a recess is provided at an end of the housing on the side of the gear case, a handle portion is connected to the stator holder so as to protrude from the recess, and the switch is accommodated in the handle.

  Further, one end of the rotation shaft of the armature is supported by the gear case and the other end is supported by the housing, and a brush that abuts against the commutator of the armature and supplies power is provided on the housing, and the stator is mounted on the stator holder. Fixed to the inner periphery, the outer periphery of the stator and the axial cross section of the inner periphery of the housing are formed in a circle, the outer periphery of the stator holder is press-fitted into the inner periphery of the housing, and the handle portion and the recess are rotated. You may engage in direction.

  The stator holder may be configured to be sandwiched between the gear case and the housing.

  Further, a soft layer made of a material softer than the handle portion may be provided on the surface of the handle portion by two-layer molding.

  From another viewpoint, the present invention relates to a motor having an armature and a stator, a metal housing that is an outer frame that houses the motor, and a gear case that is an outer frame provided adjacent to the housing, A power tool comprising a speed reduction mechanism portion that is housed in the gear case and transmits a rotational force of the motor, and a switch for controlling power supply to the motor, wherein a recess is provided on the gear case side end surface of the housing. One feature is that the resin handle portion is sandwiched between the housing and the gear case so as to protrude from the recess, and the switch is accommodated in the handle portion.

  Further, a soft layer made of a material softer than the handle portion may be provided on the surface of the handle portion by two-layer molding.

  According to the first aspect of the present invention, since the resin-made stator holder is interposed between the stator and the outside of the tool, the insulation of the stator with respect to the outside of the tool is reliably performed. In addition, since a resin handle is interposed between the switch and the outside of the tool, the switch is reliably insulated from the outside of the tool. If the stator and the switch itself are insulated, the entire tool has a double insulation structure. Further, since the housing is formed of a highly rigid metal, it does not deform even when a strong impact is applied due to, for example, the tool dropping. In addition, since the handle portion is made of a resin having low thermal conductivity, for example, even when working with a tool left in a cold place, the handle portion is gripped without feeling cold. be able to. Further, since the handle portion is connected to the stator holder, the strength of the connecting portion is high. Further, since the handle portion and the stator holder can be integrally formed, the manufacturing cost can be reduced. Therefore, a safe, strong, and easy-to-operate power tool can be provided at low cost.

  According to the second aspect of the present invention, since one end of the rotation shaft of the amateur is supported by the gear case and the other end is supported by the housing, the position of the amateur relative to the housing is accurately determined. Further, the axial cross section of the outer periphery of the stator and the inner periphery of the housing is formed in a circular shape, and the outer periphery of the stator holder is press-fitted into the inner periphery of the housing, whereby the radial position of the stator with respect to the amateur is accurately determined. Further, since the handle portion and the recess are engaged in the rotational direction, the rotational direction positions of the stator and the brush are accurately determined. Therefore, the positional relationship among the amateur, the stator, and the brush is accurately determined, and even when an impact is applied, the positional relationship is not shifted due to the high rigidity of the housing. Therefore, the performance of the power tool can be stabilized.

  According to the third aspect of the invention, since the stator holder is sandwiched between the gear case and the housing, no separate parts are required to determine the axial position of the stator holder, and the manufacturing cost can be reduced. .

  According to the invention of claim 4, since the soft layer made of a material softer than the handle portion is provided on the surface of the handle portion by two-layer molding, the local pressure applied to the hand holding the handle portion is dispersed. The hand can hardly hurt even during long hours of work. In addition, operability is improved because the hand is less likely to slip.

  An impact tool 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. In the following description, the left side of FIG. 1 is the front side of the tool, the right side is the rear side of the tool, the upper side is the upper side of the tool, the lower side is the lower side of the tool, and the depth direction is the side of the tool.

  The impact tool 1 includes a motor 2 having an armature 10 and a stator 11, a resin stator holder 3 that supports the outer periphery of the stator 11, a metal housing 4 that is an outer frame that supports the outer periphery of the stator holder, A gear case 5 that is an outer frame provided adjacent to the housing 4, a speed reduction mechanism unit 6 that is housed in the gear case 5 and transmits the rotational force of the motor, and a switch 7 that controls power supply to the motor. ing. The speed reduction mechanism 6 is connected to an impact mechanism 9 for converting a rotational force into a striking force in the rotational direction, and its tip protrudes from the front of the gear case 5 so that a tip tool such as a socket can be attached. .

  The gear case 5 includes a metal hammer case 5 </ b> A formed in a cylindrical shape, and an inner cover 5 </ b> B that is sandwiched between the hammer case 5 </ b> A and the housing 4 to partition the interior of the hammer case 5 </ b> A and the housing 4. The hammer case 5A and the inner cover 5B are formed with four bolt holes (not shown), and the housing 4 is formed with corresponding female screws (not shown). The hammer case 5 </ b> A and the inner cover 5 </ b> B are fixed to the housing 4 by inserting bolts 8 into the bolt holes (not shown) and screwing them into female screws (not shown). Four convex portions (not shown) are formed on the end surface of the inner cover 5B on the housing 4 side, and the convex portions (not shown) are engaged with the inner periphery of the housing 4 so that the inner cover 5B and the housing 4 are in the radial direction. The position of is fixed. Further, the end surface of the inner cover 5B on the side of the hammer case 5A protrudes in a cylindrical shape, and the position of the hammer case 5A and the inner cover 5B in the radial direction is determined by inserting this protruding portion into the inner periphery of the hammer case 4A. .

  One end of the rotating shaft 10 a is rotatably supported by a bearing 12 fixed to the gear case 5, and the other end of the rotating shaft 10 a is rotatably supported by a bearing 13 fixed to the housing 4. . A stator 11 is coaxially provided on the outer periphery of the armature 10 with a slight gap therebetween.

  The outer periphery of the stator 11 is press-fitted into the inner periphery of the stator holder 3, and two screw insertion holes (not shown) are formed so as to penetrate the stator 11 in the axial direction. The housing 4 is formed with two female screw portions (not shown) corresponding to the screw insertion holes. By inserting two screws (not shown) through the screw insertion holes and screwing into the female screw portions, The stator 11 is fixed to the stator holder 3.

  The stator holder 3 has a circular outer circumferential section, and the inner circumference of the housing 4 has a circular axial section. The outer diameter of the stator holder 3 is set slightly larger than the inner diameter of the housing 4, so that the stator holder 3 is press-fitted into the housing 4. The axial length of the stator holder 3 is set to be slightly smaller than the axial length of the internal space formed by the inner cover 5B and the housing 4, so that the axial position of the stator holder 3 is not shifted. It is regulated. A brush 14 that contacts the commutator 10 b of the amateur 10 and supplies electric power is mounted on the housing 4 via brush holders (not shown) provided on both side surfaces of the housing 4.

  A handle portion 15 is continuously provided below the stator holder 3. A recess 4a is formed at the front end of the housing 4 so as to allow the handle portion 15. The handle portion 15 protrudes from the recess 4a and extends outward in the radial direction. As a result, the handle portion 15 and the recess 4a are engaged, and the radial position of the stator holder 3 with respect to the housing 4 is determined.

  The front portion of the handle portion 15 is open, and a handle cover 16 is attached to the handle portion 15 with screws 17 so as to close the opening. An internal space is formed by the handle portion 15 and the handle cover 16, and the switch 7 is accommodated in this internal space. A soft layer 18 made of a material softer than the handle portion 15 is provided on the outer surface of the handle portion 15 by two-layer molding.

  According to the above configuration, since the resin-made stator holder 3 is interposed between the stator 11 and the outside of the tool, the insulation of the stator 11 with respect to the outside of the tool is ensured. Further, since the resin-made handle portion 15 is interposed between the switch 7 and the outside of the tool, the insulation of the switch 7 from the outside of the tool is ensured. If the stator 11 and the switch 7 are also insulated, the entire tool has a double insulation structure. Further, since the housing 4 is made of a highly rigid metal, it does not deform even when, for example, the tool falls and a strong impact is applied. Further, since the handle portion 15 is formed of a resin having low thermal conductivity, for example, even when working with a tool left in a cold place, the handle portion 15 is gripped without feeling cold. It can be performed. Further, since the handle portion 15 is connected to the stator holder 3, the strength of the connecting portion is high and the rigidity is also high. Moreover, since the handle | steering-wheel part 15 and the stator holder 3 can be integrally molded, manufacturing cost can be reduced. Therefore, a safe, strong, and easy-to-operate power tool can be provided at low cost.

  Furthermore, since one end of the rotating shaft 10a of the amateur 10 is supported by the gear case 5 and the other end is supported by the housing 4, the position of the amateur 10 with respect to the housing 4 is accurately determined. Further, the axial cross section of the outer periphery of the stator 11 and the inner periphery of the housing 4 is formed in a circle, and the outer periphery of the stator holder 3 is press-fitted into the inner periphery of the housing 4, so that the radial position of the stator 11 with respect to the amateur 10 is accurate. Determined. Furthermore, since the handle portion 15 and the recess 4a are engaged in the rotational direction, the rotational direction positions of the stator 11 and the brush 14 are accurately determined. Therefore, the positional relationship among the amateur 10, the stator 11, and the brush 14 is accurately determined based on the highly rigid housing 4, and even if an impact is applied, the positional relationship is not shifted due to the high rigidity of the housing 4. Therefore, the performance of the power tool can be stabilized.

  Furthermore, since the stator holder 3 is clamped between the gear case 5 and the housing 4, no separate parts are required to determine the axial position of the stator holder 3, and the manufacturing cost can be reduced.

  Furthermore, since the soft layer 18 made of a material softer than the handle portion 15 is provided on the surface of the handle portion 15 by the two-layer molding, the local pressure applied to the hand holding the handle portion 15 can be dispersed, and long Hands are less likely to hurt even with time. In addition, operability is improved because the hand is less likely to slip.

  It is also conceivable that the stator holder 3 and the handle portion 15 are provided as separate parts, or that only the handle portion 15 is provided without the stator holder 3. Even in such a configuration, since the resin-made handle portion 15 is interposed between the switch 7 and the outside of the tool, the insulation of the switch 7 from the outside of the tool is surely performed. If the stator 11 and the switch 7 are also insulated, the handle portion 15 has a double insulation structure. Further, the recess 4a is provided on the end face of the housing 4 on the side of the gear case 5, and the resin handle portion 15 is sandwiched between the housing 4 and the gear case 5 so as to protrude from the recess 4a. Thus, an electric tool compatible with the highly rigid housing 4 and the low thermal conductivity handle portion 15 can be provided at low cost. Moreover, since the handle | steering-wheel part 15 is clamped between the gear case 5 and the housing 4, the intensity | strength of a connection part is high. Therefore, a safe, strong, and easy-to-operate power tool can be provided at low cost.

Cross-sectional view of the overall structure of an impact tool according to an embodiment of the present invention External appearance front view of impact tool according to an embodiment of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Impact tool 2 Motor 3 Stator holder 4 Housing 4a Recessed part 5 Gear case 5A Hammer case 5B Inner cover 6 Reduction mechanism part 7 Switch 8 Bolt 9 Impact mechanism part 10 Amateur 10a Rotating shaft 10b Commutator 11 Stator 12 Bearing 13 Bearing 14 Brush 15 Handle part 16 Handle cover 17 Screw 18 Soft layer

Claims (6)

A motor having an amateur and a stator;
A resin-made stator holder that supports the outer periphery of the stator;
A metal housing that is an outer frame that supports the outer periphery of the stator holder;
A gear case which is an outer frame provided adjacent to the housing;
A speed reduction mechanism housed in the gear case and transmitting the rotational force of the motor;
A switch for controlling power supply to the motor;
In the electric tool with
A power tool characterized in that a concave portion is provided at an end of the housing on the side of the gear case, a handle portion is integrally connected to the stator holder so as to protrude from the concave portion, and the switch is accommodated in the handle portion. . One end of the rotation shaft of the amateur is supported by a gear case and the other end is supported by a housing,
A brush that contacts the armature commutator and can supply power is provided on the housing, the stator is fixed to the inner periphery of the stator holder, and the outer periphery of the stator and the axial cross section of the inner periphery of the housing are circular. Forming and press-fitting the outer periphery of the stator holder into the inner periphery of the housing;
The power tool according to claim 1, wherein the handle portion and the concave portion are engaged with each other . The electric power tool according to claim 1, wherein the stator holder is sandwiched between the gear case and the housing. The electric power tool according to any one of claims 1 to 3, wherein a soft layer made of a material softer than the handle portion is provided on a surface of the handle portion by two-layer molding. A motor having a stator;
A resin-made stator holder that supports the outer periphery of the stator;
A metal housing that is an outer frame that supports the outer periphery of the stator holder;
A switch for controlling power to the motor;
In the electric tool with
A power tool characterized in that a concave portion is provided in the housing, and a handle portion is integrally connected to the stator holder so as to protrude from the concave portion. A motor having an amateur having a rotating shaft extending in the front-rear direction, and a stator that covers a radially outer side of the amateur;
A resin-made stator holder that supports the outer periphery of the stator;
A speed reduction mechanism connected to the amateur;
A metal gear case that houses the reduction mechanism and is provided in front of the stator holder;
An output shaft connected to the speed reduction mechanism and protruding from the front of the gear case;
A handle portion integrally provided with the stator holder;
A switch accommodated in the handle portion;
And a metal housing that covers an outer periphery of the stator holder.