WO2019031275A1

WO2019031275A1 - Electric tool

Info

Publication number: WO2019031275A1
Application number: PCT/JP2018/028261
Authority: WO
Inventors: 村上　卓宏
Original assignee: 工機ホールディングス株式会社
Priority date: 2017-08-10
Filing date: 2018-07-27
Publication date: 2019-02-14

Abstract

Provided is an electric tool with which it is possible to suppress an increase in the diameter of an output portion while suppressing biting of a tip tool into an inner surface of the output portion. An output portion (9) includes a hole portion (914) and steel balls (923) which restrict relative movement in a front-back direction between a driver bit (P) and the output portion (9). The hole portion (914) includes six projecting portions (914A) and six recessed portions (914C). The six projecting portions (914A) abut against six side surfaces (P4) of the driver bit (P) to restrict relative rotation between the driver bit (P) and the output portion (9). The six recessed portions (914C) are recessed to the radially outer side of output portion (9) in such a way as to be separated from corner portions (P5) of the driver bit (P), and define a plurality of accommodating spaces (914a) which accommodate the corner portions (P5). The steel balls (923) are disposed in positions overlapping any of the six corner portions (P5). Regions in which the projecting portions (914A) do not abut against the side surfaces (P4) are larger than regions in which the projecting portions (914A) abut against the side surfaces (P4).

Description

Electric tool

The present invention relates to a power tool.

Hitherto, impact tools such as an impact driver and an impact wrench have been known as an example of a power tool which converts rotation of a motor into rotational striking force by a striking mechanism and transmits the rotational striking force to a tip tool. For example, Patent Document 1 has an anvil configured so as to be able to attach and detach a tip tool having a polygonal shape in an axial direction view, and an arc-shaped notch is provided on an inner surface of the anvil facing each corner of the tip tool. Impact tools are disclosed. According to this, since it is suppressed that each corner of a tip tool contacts the inner surface of an anvil directly, the advantageous effect that the stress which occurs at the time of work can be reduced is acquired.

Generally, in the electric power tool as described above, a restricting member for restricting the relative movement of the tip tool relative to the electric tool main body in the axial direction of the tip tool in order to prevent the tip tool from falling off Provided in

JP, 2013-208678, A

However, in the case where a restriction member is provided on the radial outside of the tip tool in the impact tool described in Patent Document 1, the restriction member becomes larger depending on the shape of the notch and the position of the restriction member in the circumferential direction of the tip tool. As a result, the diameter of the anvil increases, and as a result, the impact tool may be increased in size. For this reason, in the conventional structure, it is difficult to provide a large arc notch on the inner surface of the anvil.

Then, an object of this invention is to provide the electric tool which can suppress the diameter-diameter-ization of an output part, suppressing biting to the inner surface of the output part of a tip tool.

In order to solve the above problems, according to the present invention, a housing, a motor accommodated in the housing, and an output portion rotatably supported by the housing and capable of receiving a driving force of the motor and rotating about a rotation axis And the output unit has a hole into which the tip tool can be inserted, and a regulating member that regulates the relative movement between the tip tool and the output unit, and the holes are formed of a plurality of holes. A contact portion and a plurality of recessed portions, and the plurality of contact portions project radially inward of the output portion and abut on a plurality of side surfaces of the tip tool to form the tip tool and the output portion The relative rotation is restricted, and the plurality of concave portions are located between the adjacent abutment portions in the rotational direction of the output portion so as to be separated from the plurality of corners of the tip tool. A plurality of recesses recessed outwardly to receive the plurality of corners Defining the space, the restriction member is disposed at a position overlapping any one of the plurality of corner portions, and the contact portion is the side surface in a state in which the tip tool is inserted into the hole portion The electric power tool is characterized in that a region where the contact portion does not contact the side surface is larger than a region where the contact portion abuts.

According to the power tool of the above configuration, since the plurality of corner portions of the tip tool are accommodated in a state separated from the inner surface of the hole portion, the plurality of corner portions of the tip tool bite into the inner surface of the hole portion Can be suitably suppressed. In addition, since the non-contacting area where contact can not be made is larger than the contact area where contact can be made on each side, the contact between the output part and the tip tool is made on each side of the tip tool It can arrange | position in the center vicinity, and it becomes possible to suppress suitably that the corner | angular part of a tip tool bites into the inner surface of a hole. Furthermore, since the restricting member is disposed to overlap with one of the plurality of corner portions, the contact portion located relatively near the tip tool in the circumferential direction of the output portion is processed, etc. Since the control member can be supported by applying the above, the increase in size of the control member can be suppressed, and the diameter increase of the output part can be suppressed. That is, it is possible to suppress an increase in diameter of the output portion while suppressing biting of the tip end tool onto the inner surface of the output portion.

In the above configuration, each of the plurality of contact portions has a plurality of contact surfaces that contact each of the plurality of side surfaces, and the plurality of contact surfaces in the rotational direction of the rotation axis and the output portion The angle formed by the two imaginary straight lines when connecting each of the upstream end and the downstream end of each of the two is the downstream end adjacent with respect to the adjacent contact surface in the rotational direction of the rotation axis and the output portion Preferably, the angle is smaller than the angle formed by the two imaginary straight lines when connecting with each of the upstream ends.

According to such a configuration, it is possible to preferably suppress that the corner of the tip tool bites into the inner surface of the hole.

Preferably, inflection points are present on both sides of the plurality of contact portions in the rotational direction of the output portion in a cross section orthogonal to the rotation axis.

According to such a configuration, by the presence of the inflection point, a plurality of storage spaces can be suitably defined, and it is possible to suppress that the corner of the tip tool bites into the inner surface of the hole. It becomes.

Moreover, it is preferable that the said recessed part defines several said accommodation space by presence of the said inflexion point.

Further, the distance from the straight line connecting the inflection points located on both sides in the circumferential direction of each of the plurality of abutting portions to the projecting end of the abutting portion is the both sides in the circumferential direction of each of the plurality of recessed portions It is preferable that the distance between the straight line connecting the inflection points located in and the distance from the concave end of the recess be smaller.

The present invention further includes a housing, a motor accommodated in the housing, and an output portion rotatably supported by the housing and capable of receiving a driving force of the motor and rotating around a rotation axis. The output unit includes a hole into which a tip tool can be inserted, and a regulating member that regulates relative movement between the tip tool and the output unit, and the hole includes a plurality of contact portions and a plurality of contact portions. And a plurality of the contact portions project radially inward of the output portion and contact a plurality of side surfaces of the tip tool to restrict relative rotation between the tip tool and the output portion. The plurality of concave portions have surfaces that are orthogonal to the radial direction of the output portion and face the plurality of corner portions of the tip tool, and are positioned between adjacent abutment portions in the rotational direction of the output portion The output is spaced apart from the plurality of corners of the tip tool A plurality of housing spaces are formed, which are recessed radially outward of the housing to accommodate a plurality of the corner portions, and the regulation member is disposed so as to overlap with any one of the side surfaces. We provide power tools.

According to the power tool of the above configuration, since the plurality of corner portions of the tip tool are accommodated in a state separated from the inner surface of the hole portion, the plurality of corner portions of the tip tool bite into the inner surface of the hole portion Can be suitably suppressed. In addition, since the concave portion has a surface orthogonal to the radial direction of the output portion and facing the corner portion, even when the restricting member is disposed at a position overlapping with any of the plurality of side surfaces, the large size of the restricting member Can be suppressed, and it can be suppressed that the diameter of the output part is increased.

In the above configuration, at least a part of the tip tool has a polygonal shape, the polygonal shape has a hexagonal prism shape, the plurality of contact portions are six contact portions, and the plurality of side surfaces Are preferably six side surfaces, and the six abutment portions preferably abut each of the six side surfaces.

According to such a configuration, it is possible to preferably suppress that the plurality of corner portions of the tip tool bite into the inner surface of the hole.

Further, it is preferable that the hexagonal prism shape is a regular hexagonal prism shape, and the plurality of abutment portions abut on central portions of the six side surfaces in a cross section orthogonal to the first direction.

Further, the restriction member is movably provided between a first position and a second position closer to the rotation axis than the first position in the radial direction of the output portion, and is positioned at the first position. In the case where the tip tool is inserted into the hole, relative movement between the tip tool and the output portion is allowed, and when the tip tool is positioned at the second position, the tip tool is inserted into the hole It is preferable to restrict relative movement between the tip tool and the output unit in the state where

According to such a configuration, it is possible to preferably suppress the falling-off of the tip tool from the power tool body by the tip tool moving relative to the power tool body.

Moreover, it is preferable that the said limitation member is a steel ball.

Moreover, it is preferable that the said adjacent recessed part and the said contact part are connected by predetermined | prescribed curvature.

The present invention further includes a housing, a motor accommodated in the housing, and an output portion rotatably supported by the housing and capable of receiving a driving force of the motor and rotating around a rotation axis. The output unit includes a hole into which a tip tool can be inserted, and a regulating member that regulates relative movement between the tip tool and the output unit, and the hole includes a plurality of contact portions and a plurality of contact portions. And a plurality of the contact portions project radially inward of the output portion and contact a plurality of side surfaces of the tip tool to restrict relative rotation between the tip tool and the output portion. The plurality of recessed portions are located between the abutting portions adjacent to each other in the rotational direction of the output portion, and both sides in the rotational direction of the output portions of the plurality of abutting portions in a cross section orthogonal to the rotation axis The tip by the presence of an inflection point A plurality of housing spaces are formed which are recessed outward in the radial direction of the output portion so as to be separated from a plurality of corner portions of the tool to define a plurality of housing spaces for housing the corner portions; A distance from a straight line connecting the inflection points, which is disposed at a position overlapping one of the two in the circumferential direction of each of the plurality of the contact portions, to a projecting end of the contact portion is a plurality of the concave portions The electric power tool is characterized in that it is smaller than the distance from the straight line connecting the inflection points located on both sides in each circumferential direction of the to the concave end of the recess.

According to the power tool of the above configuration, since the plurality of corner portions of the tip tool are accommodated in a state separated from the inner surface of the hole portion, the plurality of corner portions of the tip tool bite into the inner surface of the hole portion Can be suitably suppressed. Further, since the restricting member is arranged to overlap with one of the plurality of corner portions, the contact portion located relatively near the tip tool in the circumferential direction of the output portion is processed, etc. Since the control member can be supported by applying the above, the increase in size of the control member can be suppressed, and the diameter increase of the output part can be suppressed. That is, it is possible to suppress an increase in diameter of the output portion while suppressing biting of the tip end tool onto the inner surface of the output portion.

Preferably, a curve is connected to the inflection point.

According to the present invention, it is possible to suppress an increase in diameter of the output portion while suppressing biting of the tip tool into the output portion.

It is sectional drawing of the impact driver concerning embodiment of this invention. It is a perspective view of the anvil of the impact driver concerning an embodiment of the invention. It is a front view of the anvil of the impact driver concerning an embodiment of the invention. It is a figure which shows the driver bit which is an example of the tip tool which can be attached or detached to the output part of the impact driver concerning embodiment of this invention. FIG. 5 is a cross-sectional view taken along the line V-V of FIG. It is a partially expanded view (the 1) of FIG. It is a partially expanded view (the 2) of FIG. FIG. 8 is a cross-sectional view taken along line VIII-VIII of FIG. It is a perspective view of the anvil of the impact driver concerning an embodiment of the invention, and the state where a driver bit is inserted in the hole of an anvil is shown. FIG. 8A shows a comparative example in which a steel ball is disposed at a position overlapping with the side surface of the driver bit. FIG. 8 (b) shows the arrangement of steel balls in the impact driver according to the present embodiment. It is a figure (the 1) explaining operation which mounts a driver bit to an output part of an impact driver concerning an embodiment of the invention. It is a figure (the 2) explaining operation which mounts a driver bit to an output part of an impact driver concerning an embodiment of the invention. It is a figure (the 3) explaining operation which mounts a driver bit to an output part of an impact driver concerning an embodiment of the invention. It is a figure which shows the engagement relation of the hole part and driver bit at the time of operation | work using the impact driver concerning embodiment of this invention, (a) shows the time of non-operation, (b) shows the time of operation. ing. It is front sectional drawing which shows the modification of a hole. It is a figure which shows the engagement relationship of the hole part and driver bit at the time of the operation | work using the conventional impact driver, (a) shows the time of non-operation, (b) shows the time of operation. It is the schematic which showed the stress which generate | occur | produces in an anvil in the clamping operation | work using the impact driver concerning embodiment of this invention, and a deformation state. It is the schematic which showed the stress which generate | occur | produces in an anvil in the clamping operation | work using the conventional impact driver, and a deformation | transformation state.

Hereinafter, an impact driver 1 which is an example of the electric power tool according to the first embodiment of the present invention will be described based on FIGS. 1 to 14. The impact driver 1 is an electric power tool for fastening a fastener (such as a screw) to a workpiece (such as steel or wood).

In the following description, the "upper" shown in FIG. 1 is defined as the upper direction, the "lower" as the lower direction, the "front" as the front direction, and the "rear" as the rear direction. Further, the “right” when the impact driver 1 is viewed from the rear is defined as the right direction, and the “left” is defined as the left direction. When dimensions, numerical values, etc. are referred to in the present specification, not only dimensions and numerical values that completely match the relevant dimensions, numerical values, etc., but also substantially similar dimensions, numerical values, etc. (for example, Shall be included. Similarly, "substantially identical", "substantially orthogonal", "substantially parallel", "substantially identical", "substantially identical" for "identical", "orthogonal", "parallel", "coincidence", "planar", etc. Etc. shall be included.

As shown in FIG. 1, the impact driver 1 includes an output unit to which a motor 4, an inverter circuit board unit 5, a control unit 6, a gear mechanism 7, an impact mechanism 8 and a driver bit P can be attached and detached. And 9). The outer shell of the impact driver 1 is configured to include a main body housing 2 and a hammer case 3. As shown in FIG. 1, in the present embodiment, the impact driver 1 uses the power of the secondary battery accommodated in the battery pack Q as a driving power supply. In the following description, unless otherwise stated, the description will be made on the basis of the state in which the driver bit P is attached to the output unit 9. The main body housing 2 and the hammer case 3 are examples of the "housing" in the present invention.

The main body housing 2 is made of resin, and has a body portion 21 and a handle portion 22.

The body portion 21 has a substantially cylindrical shape extending in the front-rear direction, and accommodates the motor 4 and the inverter circuit board portion 5.

The handle portion 22 extends downward from the front end of the lower surface of the body portion 21 and is integrally formed with the body portion 21. The control unit 6 is accommodated in the lower portion of the handle portion 22.

A trigger switch 22A operated by the operator is provided at the upper front portion of the handle portion 22, and a switch mechanism 22B connected to the control unit 6 is provided inside the handle portion 22. The switch mechanism 22B controls a tool start signal for starting the motor 4 when the trigger switch 22A is pulled or started (for example, pushed into the handle portion 22 by the finger of the operator) Output to the unit 6 and stop the output of the tool start signal when the pulling operation on the trigger switch 22A is released or stopped (for example, when the operator removes the finger from the trigger switch 22A and cancels the pulling operation) Is configured.

At the lower end portion of the handle portion 22, a battery mounting portion 22C capable of mounting the battery pack Q is provided. The battery mounting portion 22C is provided with a battery connection terminal portion 22D which is electrically connected to a terminal portion (not shown) of the battery pack Q when the battery pack Q is mounted.

The hammer case 3 is made of aluminum, is provided in front of the body portion 21 and has a substantially cylindrical shape. The hammer case 3 accommodates the gear mechanism 7, the impact mechanism 8, and a part of the output unit 9 in this order in the forward direction.

The motor 4 shown in FIG. 1 is a DC brushless motor, and includes a rotating shaft 41, a rotor 42, and a stator 43.

The rotating shaft 41 extends in the front-rear direction, and is rotatably supported by the body portion 21 via a bearing.

The rotor 42 is a rotor having a plurality of permanent magnets (not shown) and extends in the front-rear direction. The rotor 42 is fixed to the rotating shaft 41 so as to rotate integrally with the rotating shaft 41.

The stator 43 is a stator having a plurality of stator windings (not shown). The stator 43 is fixed to the body 21 so as to surround the rotor 42.

The inverter circuit board unit 5 is provided at the rear of the stator 43. The inverter circuit board unit 5 has a substrate 50. The substrate 50 is fixed to the stator 43 via an insulator. Mounted on the substrate 50 are a magnetic sensor 51 for detecting the rotational position of the rotor 42, an inverter circuit (not shown) for supplying electric power of the battery pack Q to the motor 4 and controlling the rotation of the motor 4 It is done.

The control unit 6 is fixed inside the lower portion of the handle portion 22. The control unit 6 has a flat substrate 60. On the substrate 60, various circuits for controlling the motor 4 and the like are mounted. The control unit 6 is electrically connected to the inverter circuit board unit 5.

As shown in FIG. 1, the gear mechanism 7 includes a pinion gear 71 provided at the front end of the rotation shaft 41 of the motor 4, a pair of gears 72 meshing with the pinion gear 71, and a pair of gears 72. And a meshing outer gear 73. The gear mechanism 7 is a planetary gear mechanism in which the pinion gear 71 is a sun gear and the pair of gears 72 is a planetary gear, and is configured to be capable of decelerating the rotation from the pinion gear 71 and transmitting it to the impact mechanism 8.

As shown in FIG. 1, the impact mechanism 8 has a spindle 81, a ball 82, a spring 83 and a hammer 84.

The spindle 81 extends in the front-rear direction. The spindle 81 is formed with a pair of substantially V-shaped grooves 81 a facing each other in the diameter direction of the spindle 81. In the groove 81a, a ball 82 is provided movably along the groove. A fitting groove 81 b is formed at the front of the spindle 81.

The spring 83 is a coil spring and is mounted on the spindle 81. The spring 83 biases the hammer 84 forward via a washer.

The hammer 84 is rotatably disposed about an axial center A extending in the front-rear direction, and has a hammer main body 84A extending in the front-rear direction, and a plurality of claws 84B projecting from the front end of the hammer main body 84A. doing. While the hammer 84 is biased forward by the spring 83, it is also possible to move backward against the biasing force.

Further, two grooves 84a recessed outward in the radial direction of the hammer main body 84A are formed in the front inner peripheral portion of the hammer main body 84A. Each groove 84a is formed at a position opposed to each groove 81a of the spindle 81, and supports the ball 82 together with the groove 81a. As a result, the hammer 84 is held relative to the spindle 81, and the ball 82 can move in the groove 81a to move the hammer 84 relative to the spindle 81 in the longitudinal and circumferential directions. .

The output unit 9 is configured to be able to detachably attach the driver bit P, and has an anvil 91 and a tip tool holding unit 92 as shown in FIG. 1. In the following description, the description will be made on the basis of the state in which the driver bit P is mounted to the output unit 9, unless otherwise stated. The output unit 9 is an example of the “output unit” in the present invention.

As shown in FIGS. 1 and 2, the anvil 91 includes a blade portion 911, a large diameter portion 912, a reduced diameter portion 913, a hole 914, and a fitting portion 915.

The large diameter portion 912 is formed in a substantially cylindrical shape extending in the front-rear direction, and as shown in FIG. 1, the large diameter portion 912 is rotatably supported by the hammer case 3 about the shaft center A in a state of being inserted into a bearing. ing. In addition, the blade portion 911, the large diameter portion 912, the reduced diameter portion 913, the hole portion 914, and the fitting portion 915 are integrally formed, and the large diameter portion 912 rotates about the axis A, whereby the anvil 91 Integrally rotates around the axis A. The axis A is an example of the “rotation axis” in the present invention.

As shown in FIGS. 1 and 2, the reduced diameter portion 913 is formed in a substantially cylindrical shape extending forward from the front end of the large diameter portion 912. The outer diameter of the reduced diameter portion 913 is smaller than the outer diameter of the large diameter portion 912. At the rear of the reduced diameter portion 913, a steel ball holding hole 91a which penetrates the reduced diameter portion 913 in the radial direction of the anvil 91 is formed. The steel ball holding holes 91a are formed at two opposite sides of the anvil 91 in the diametrical direction with respect to the axial center A (see FIG. 7).

The wing portion 911 is provided at the rear of the large diameter portion 912 and protrudes outward in the radial direction of the anvil 91. As shown in FIG. 3, three blade portions 911 are provided at intervals of approximately 120 degrees in the circumferential direction of the anvil 91.

As shown in FIG. 1, the fitting portion 915 forms the rear of the anvil 91 and extends in the front-rear direction. The fitting portion 915 is fitted in the fitting groove 81 b of the spindle 81.

As shown in FIG. 1, the hole 914 extends from the front end of the reduced diameter portion 913 to a substantially central portion of the large diameter portion 912 in the front-rear direction. As shown in FIGS. 2 and 3, the hole 914 has a plurality of protrusions 914A and a plurality of recesses 914C. The hole 914 is an example of the “hole” in the present invention.

As shown in FIG. 3, the plurality of protrusions 914 </ b> A protrude radially inward from the inner surface of the anvil 91. In the circumferential direction of the anvil 91, six protrusions 914A are provided at equal intervals every 60 degrees. An abutting surface 914B is defined on each of the protruding end surfaces of the plurality of protrusions 914A. The abutment surface 914B is defined as a flat surface and can abut on each of the plurality of side surfaces P4 of the driver bit P. The protrusion 914A is an example of the “contact portion” in the present invention. The contact surface 914B is an example of the contact surface in the present invention.

The plurality of recesses 914C are recessed outward in the radial direction of the anvil 91 from the inner surface of the anvil 91 with a predetermined curvature. In the circumferential direction of the anvil 91, six recessed portions 914C are provided at equal intervals every 60 degrees. Each of the six recesses 914C is located between two adjacent protrusions 914A in the circumferential direction of the anvil 91. The recess 914C is an example of the "recess" in the present invention.

Further, an insertion hole 91b extending in the front-rear direction is formed by the plurality of protrusions 914A and the plurality of recesses 914C.

Further, each of the plurality of recessed portions 914C is recessed outward in the radial direction of the anvil 91, thereby defining a plurality of corner portion accommodation spaces 914a. More specifically, in the cross section orthogonal to the axial center A, the plurality of projections 914A have inflection points R3 and R4 on both sides in the rotational direction of the output unit 9, and therefore the recess 914C has a plurality of corners of the driver bit P. A plurality of corner portion accommodation spaces 914a are defined by being recessed outward in the radial direction of the output portion 9 so as to be separated from the portion P5 (see FIG. 6). In addition, a curve is connected to the inflection point. Here, the inflection point means a point at which the bending direction is changed by a curve on a cross section orthogonal to the axial center A. In other words, the point at which the sign (plus or minus) of the curvature changes on the curve.

The detailed configuration of the hole 914 with respect to the cross section taken along line VIII-VIII in FIG. 1 will be described later.

As shown in FIG. 1, the tip tool holder 92 includes a cylindrical member 921, a spring 922, a steel ball 923, and a restriction ring 924.

The cylindrical member 921 is formed in a substantially cylindrical shape extending in the front-rear direction. At a rear portion of the cylindrical member 921, a restricting projection 921 </ b> A which protrudes inward in the radial direction of the cylindrical member 921 from the inner surface of the cylindrical member 921 is provided immovably with respect to the cylindrical member 921. Further, the cylindrical member 921 is provided with a protrusion 921 B which protrudes inward in the radial direction of the cylindrical member 921 from the inner surface of the cylindrical member 921 in front of the restriction protrusion 921 A. The protrusion 921 B is provided so as to be movable relative to the cylindrical member 921 in the front-rear direction.

The spring 922 is a coil spring, and is disposed between the protrusion 921B and the restriction protrusion 921A on the inner circumferential surface of the cylindrical member 921. The front end of the spring 922 is seated on the rear surface of the projection 921 B, and the rear end of the spring 922 is seated on the front of the regulation projection 921 A. By being urged forward by the spring 922, the projection 921B is located at the front of the cylindrical member 921.

The steel ball 923 is a metallic spherical member. One steel ball 923 is disposed in each of two steel ball holding holes 91 a of the anvil 91. The diameter of the steel ball 923 is substantially the same as the inner diameter of the steel ball holding hole 91a. In addition, the radial outward movement of the steel ball 923 is restricted by the restriction protrusion 921A of the cylindrical member 921. The detailed aspect in which the steel ball holding hole 91a holds the steel ball 923 will be described later. The steel ball 923 is an example of the “regulating member” and the “steel ball” in the present invention.

The restriction ring 924 is fitted in a groove formed to extend in the circumferential direction of the reduced diameter portion 913 on the outer peripheral surface of the front portion of the reduced diameter portion 913. The restriction ring 924 protrudes outward in the radial direction of the anvil 91 from the outer peripheral surface of the reduced diameter portion 913. The front surface of the projection 921B is in contact with the restriction ring 924, and the restriction ring 924 defines the forward position of the projection 921B.

Next, a driver bit P, which is an example of a tip tool that can be attached to and detached from the output unit 9 of the impact driver 1 according to the present embodiment, will be described with reference to FIGS. 4 and 5. In the following description, the description will be made based on a state in which the driver bit is positioned such that the axial center of the driver bit P is parallel to the front-rear direction. The driver bit P has a tip portion P1, a prismatic portion P2, and a groove P3. As shown in FIG. 4, the driver bits P are formed substantially symmetrically with respect to the front-rear direction. As shown in FIG. 5, the driver bit P has a polygonal shape in a front view. Specifically, the driver bit P has a regular hexagonal shape in front view.

The front end P1 has a tapered shape located at the front end and the rear end of the driver bit P, and is configured to be engageable with a not-shown fastening member (for example, a screw head). In the present embodiment, the front end portion P1 is cut out in a substantially cross shape in a front view.

The prismatic portion P2 is a portion having a regular hexagonal shape extending in the front-rear direction, and has six side surfaces P4 and six corner portions P5.

The six side surfaces P4 are surfaces extending in the front-rear direction. As shown in FIG. 5, the angle of the inner angle of the driver bit P in a front view formed by two side faces P4 adjacent to each other in the circumferential direction of the driver bit P, corresponding to the prismatic portion P2 having a regular hexagonal shape. Is approximately 120 degrees. Six aspects are examples of the "plural aspects" in the present invention.

The six corners P5 are defined by two adjacent side faces P4 and extend in the front-rear direction. As shown in FIG. 5, since the angle of the internal angle of the driver bit P in a front view formed by the adjacent side surfaces P4 is smaller than 180 degrees (approximately 120 degrees), the corner P5 is outside the radial direction of the driver bit P. It protrudes to the direction. Further, in the front view, the corner portion P5 is located farther from the axial center A than the side surface P4.

The grooves P3 are formed substantially symmetrically on the front and rear of the driver bit P. The groove P3 is an annular groove which is recessed inward in the radial direction of the driver bit P and is formed in a direction orthogonal to the front-rear direction of the driver bit P. The groove P3 is formed to extend in the circumferential direction of the driver bit P.

Next, with reference to FIGS. 5 to 9, the engagement between the output portion 9 and the driver bit P when the driver bit P is attached to the output portion 9 of the impact driver 1 according to the present embodiment will be described. This will be described in detail with reference to the configuration of the hole 914 with respect to the cross section along line VIII-VIII of FIG.

As shown in FIG. 5, the side surface P4 of the driver bit P and the contact surface 914B of the projection 914A of the hole 914 are in contact at a substantially central portion of each side surface P4 in front view. Thereby, relative rotation between the driver bit P and the anvil 91 is restricted.

As shown in FIG. 5, the corner P5 and the recess 914C face each other. The corner P5 is located in the corner accommodation space 914a. That is, the corner portion P5 is separated from the inner surface of the anvil 91.

Further, when driver bit P is inserted into hole 914, the non-contacting area where contact can not be made is larger than the contact area where projection 914A can contact on each side P4 of driver bit P. ing. Thereby, the contact point between the anvil 91 and the driver bit P can be arranged near the center of each side P4 of the driver bit P, and when a high load is applied to the anvil 91 at the time of tightening operation, the corner portion of the driver bit P It becomes possible to suppress that P5 bites into the inner surface of anvil 91.

Further, in the circumferential direction of the anvil 91, the adjacent protrusion 914A and the recess 914C are connected by a smooth curve. In other words, the adjacent recess 914C and the projection 914A are connected with a predetermined curvature. As a result, when a high load is applied to the anvil 91 during the tightening operation, it is possible to suppress the corner portion P5 of the driver bit P from being caught in the inner surface of the anvil 91.

The angle α1 shown in FIG. 6 is, in a cross section orthogonal to the axial direction of the anvil 91, the upstream end R2 and the downstream end R1 of the plurality of abutment surfaces 914B in the rotational direction of the rotation axis A and the output portion 9. Shows the angles formed by the two imaginary straight lines when connecting with Further, the angle β1 corresponds to the downstream end R1 of one abutment surface 914B and the upstream end R2 of the other abutment surface 914B with respect to the adjacent abutment surfaces 914B in the rotational direction of the rotation axis A and the output unit 9. An angle formed by two virtual straight lines when connected is shown. In the present embodiment, the angle α1 is smaller than the angle β1. As a result, when a high load is applied to the anvil 91 during the tightening operation, it is possible to suppress the corner portion P5 of the driver bit P from being caught in the inner surface of the anvil 91. In the present embodiment, the "rotational direction" in which the output unit 9 and the driver bit P rotate is the counterclockwise direction in FIGS.

L1 shown in FIG. 7 indicates the distance from the straight line connecting inflection points R3 and R4 located on both sides in the circumferential direction of each of the plurality of protrusions 914A to the protruding end of the protrusion 914A. Further, L2 indicates a distance from a straight line connecting inflection points R4 and R3 located on both sides in the circumferential direction of each of the plurality of recesses 914C to the concave end (the deepest position) of the recesses. In the present embodiment, L1 is configured smaller than L2. By suitably separating the corner P5 of the driver bit P and the inner surface of the anvil 91, the corner P5 of the driver bit P is engaged with the inner surface of the anvil 91 when a high load is applied to the anvil 91 at the time of tightening operation. It is possible to suppress the jamming.

The angle α2 shown in FIG. 7 is an inflection point located upstream of each of the plurality of protrusions 914A in the rotational direction of the rotation axis A and the output portion 9 in a cross section orthogonal to the axial direction of the anvil 91 An angle formed by two virtual straight lines when R4 and each of the inflection points R3 located on the downstream side are connected is shown. Further, the angle β2 is located upstream of the inflection point R3 located on the downstream side of one protrusion 914A and the other protrusion 914A with respect to the adjacent protrusion 914A in the rotational direction of the rotation axis A and the output unit 9 It shows the angle formed by the two virtual straight lines when connecting with each of the inflection points R4. In the present embodiment, the angle α2 is smaller than the angle β2. As a result, when a high load is applied to the anvil 91 during the tightening operation, it is possible to suppress the corner portion P5 of the driver bit P from being caught in the inner surface of the anvil 91.

As shown in FIG. 9, each steel ball holding hole 91 a is located at substantially the same position as one of the six corner portions P <b> 5 in the circumferential direction of the anvil 91. As shown in FIG. 8, the hole 914 further includes a steel ball retaining projection 914D. The steel ball holding projection 914D protrudes radially inward of the steel ball holding hole 91a from the steel ball holding hole 91a. In FIG. 8, the steel ball 923 is engaged with the groove P3 in the front-rear direction. As shown in FIG. 8, the distance D between the projecting end faces of the steel ball holding projections 914 D in front view is smaller than the diameter of the steel balls 923, and the steel balls 923 and the steel ball holding projections 914 D are anvils 91. The radial inward movement of the steel ball 923 is restricted by abutting in the radial direction. The steel ball 923 and any one of the six corner portions P5 of the driver bit P overlap in a front view. In addition, at least a part of the steel ball 923 overlaps the groove P3 of the driver bit P in a front view, and the steel ball 923 and the groove P3 are engaged even when a forward force is applied to the driver bit P. Dropping of the bit P is suppressed.

Here, referring to FIG. 10, steel ball 923 is arranged to overlap with any one of six corner portions P5 of driver bit P in a front view in a state where driver bit P is inserted into hole 914. Will be described in comparison with the case where the steel ball is disposed to overlap with any of the six side faces of the driver bit. FIG. 10A shows a comparative example in which a steel ball 2923 is disposed at a position overlapping with the side surface P4. FIG. 10 (b) shows the arrangement of steel balls 923 in the impact driver 1 according to the present embodiment.

As shown in FIG. 10A, when the steel ball 923 is provided so as to overlap any of the side surfaces P4 of the driver bit P, the steel ball 923 is located at both ends of the side surface P4 in the rotational direction of the driver bit P. Since the concave portion 914C is recessed outward in the radial direction of the anvil 91, the position of the steel ball holding projection 2914D is a position away from the driver bit P in the radial direction of the anvil 91. Further, the side surface P4 is located closer to the rotation axis center than the corner portion P5. That is, in the case of restricting the driver bit P using a steel ball, at least a part of the driver bit P and at least a part of the steel ball need to overlap in a front view. In this position, the steel ball holding projection 2914D is located, and on the contrary, the side surface P4 of the driver bit P is located near the rotational axis center, so the steel ball 2923 having a relatively large diameter is placed in the steel ball holding hole 291a. It is necessary to arrange. When such a large diameter steel ball 2923 is used, the diameter of the anvil increases, and as a result, the impact driver main body may be enlarged.

On the other hand, as shown in FIG. 10 (b), in the present embodiment, the steel ball holding projection 914D is formed by cutting out the portion of the projection 914A that protrudes radially inward. As a result, the position of the steel ball holding projection 914D is close to the driver bit P. Furthermore, the corner P5 is located farther from the axial center A than the side P4. Therefore, it is not necessary to increase the diameter of the steel ball 293, and it is possible to suppress the increase in diameter of the anvil 91, and to suppress the increase in size of the impact driver main body.

Next, an operation of attaching the driver bit P to the output unit 9 prior to work will be described in detail with reference to FIGS. 11 to 13.

First, the operator brings the tip portion P1 of the driver bit P close to the hole portion 914, as shown in FIG.

Next, the operator slides the cylindrical member 921 forward against the biasing force of the spring 922 against the anvil 91, as shown in FIG. Along with the forward movement of the cylindrical member 921, the restriction protrusion 921 A moves forward, and the restriction of the radial outward movement of the anvil 91 with respect to the steel ball 923 by the restriction protrusion 921 A is released. Thereby, the steel ball 923 can move to a position not overlapping the groove P3 of the driver bit P in the front-rear direction (radial direction). As described above, the position at which the steel ball 923 and the groove P3 do not overlap in the front-rear direction view is an example of the “first position” in the present invention.

In this state, the operator inserts the driver bit P rearward from the end P1 into the insertion hole 91b of the hole 914. In this case, as shown in FIG. 12, when the driver bit P is inserted into the insertion hole 91b, the steel ball 923 is pushed outward in the radial direction of the anvil 91 by the outer peripheral surface of the driver bit P. The driver bit P can be inserted to the back of the insertion hole 91b.

As shown in FIG. 13, in the present embodiment, the driver bit P is inserted to a position where the groove P3 and the steel ball 923 overlap in the vertical and horizontal directions.

In this state, the worker releases the hand from the cylindrical member 921. Then, the cylindrical member 921 moves rearward with respect to the anvil 91 by the biasing force of the spring 922. Along with the rearward movement of the cylindrical member 921, the restriction protrusion 921 A moves rearward, and the outward movement of the anvil 91 with respect to the steel ball 923 in the radial direction is restricted by the restriction protrusion 921 A. At this time, the steel ball 923 is located at a position overlapping the corner portion P5 in the front-rear direction (radial direction) of the anvil 91, and regulates the relative movement of the driver bit P and the anvil 91 in the front-rear direction. Thus, the position at which the steel ball 923 and the groove P3 overlap with each other in the front-rear direction view is an example of the “second position” in the present invention.

Next, a tightening operation using the impact driver 1 according to the embodiment of the present invention will be described in detail with reference to FIG. 1, FIG. 14 and FIG. In addition, below, it demonstrates, comparing with the case where the conventional impact driver is used. As shown in FIG. 16, the anvil 500 in the conventional impact driver has a hole 5914 formed in substantially the same shape as the driver bit P, which has a regular hexagonal column shape in a front view.

When the operator pulls the trigger switch 22A of the handle portion 22, the control unit 6 starts drive control of the motor 4. When the drive control is started, the electric power of the secondary battery accommodated in the battery pack Q is supplied to the motor 4 and the rotating shaft 41 is rotated. The rotational force of the rotating shaft 41 is transmitted to the spindle 81 via the gear mechanism 7.

When the spindle 81 is rotated by the motor 4, the ball 82, the hammer 84, and the anvil 91 rotate together with the spindle 81, and a tightening operation of a screw or the like is started.

As the load on the anvil 91 becomes heavier as the tightening operation progresses, the hammer 84 rotates and retreats against the biasing force of the spring 83. At this time, the ball 82 moves rearward in the groove 81a. Then, when the claw portion 84B passes over the blade portion, the engagement between the hammer 84 and the anvil 91 is released, and the hammer 84 is separated from the anvil 91. Thereafter, the elastic energy stored in the spring 83 is released, and the hammer 84 moves forward while rotating relative to the spindle 81 via the ball 82. As a result, one claw 84B of the hammer 84 collides with one blade of the anvil, and at the same time, the other claw 84B collides with the other blade, and the hammer 84 and the anvil 91 engage with each other. Thereby, the blade portion 911 is struck.

When the same operation is performed using the conventional impact driver shown in FIG. 16, as shown in FIG. 16B, the corner P ′ 5 of the driver bit P ′ is a hole 5914. There is a possibility that the corner portion P ′ 5 may bite into the inner surface of the anvil 591 while in contact with the contact surface 5914 B of the second embodiment and the driver bit P ′ can not be taken out from the anvil 91.

On the other hand, as shown in FIG. 14, in the impact driver 1 according to the present embodiment, the corner P5 is located in the corner accommodation space 914a. According to such a configuration, even when the driver bit P is rotated relative to the anvil 91, biting of the corner portion P5 on the inner surface of the anvil 91 can be suppressed.

The embodiment of the present invention has been described above. The embodiment is an exemplification, and it is understood by those skilled in the art that various modifications can be made to the combination of the respective constituent elements, and such modifications are also within the scope of the present invention.

Next, a modification of the above-described embodiment will be described with reference to FIG.

As shown in FIG. 15, a protrusion 1914A and a recess 1914C are provided in the hole 1914 of this modification. Further, the steel ball 1923 is provided at a position overlapping with any of the side surface P4 of the driver bit P.

The protrusion 1914A extends in the same direction as the side surface P4 of the driver bit P, and has an abutting surface 1914B that can abut on the side surface P4. Thereby, the relative rotation of the driver bit P with respect to the anvil 91 is regulated, and the driver bit P can be stably held.

The recess 1914 C has a surface 1914 D that faces the corner P 5 and is orthogonal to the radial direction of the anvil 91. In this variation, steel ball holding projections 1914E can be provided near steel ball 1923 by reducing the depression of recess 1914C in this manner, and the distance between steel ball holding projections 1914E can be reduced. Even when the steel ball 1923 is provided at a position overlapping the side surface P4 of the driver bit P, it is not necessary to increase the diameter of the steel ball, and the increase in diameter of the output portion can be suppressed.

FIG. 17 is a schematic view showing stress generated in the anvil 91 and the driver bit P in a tightening operation using the impact driver 1 according to the embodiment of the present invention, and a deformed state. FIG. 18 is a schematic view showing the stress generated in the anvil 591 and the driver bit P ′ and the deformed state in the tightening operation using a conventional impact driver. 16 and 17 show a state in which a high load is applied to the anvil.

In the conventional anvil 591, a stress σ 51, a stress σ 52 and a stress σ 53 are generated in the anvil 591 by the load F 5 acting. Since the anvil hole contact point is located near the edge portion of the driver bit and the distance L53 between the edge portion of the driver bit and the anvil hole contact point is small, the edge of the driver bit is deformed when the anvil 591 is radially deformed by stress. In order to contact with the contact surface 5914B and run on the anvil hole smooth portion, there was a problem that the driver bit bites.

On the other hand, in the anvil 91 according to the present embodiment as well, the stress .sigma.1, the stress .sigma.2 and the stress .sigma.3 are generated in the anvil 91 when the load F acts, but the anvil 91 is compared to the anvil 591. Since the radius of the curve is large, the stress .sigma. Is small and the deformation in the radial direction is also small, so that the edge portion of the driver bit can be in contact with the contact surface 914B to make it difficult to run on the anvil hole smooth portion. In addition, since the distance L3 between the edge portion of the driver bit and the anvil hole contact point can be increased by positioning the anvil hole contact point near the center of the abutment surface 5914B, the edge portion of the driver bit abuts It can be made difficult to contact the surface 914B and get on the anvil hole smooth portion.

In the present embodiment, the impact driver 1 has been described as an example, but the present invention is also applicable to an electric power tool driven by a motor other than the impact driver, for example, an electric power tool such as a driver drill or an impact wrench.

Moreover, in the present embodiment, the contents related to the prevention of the increase in the impact driver size and the bit biting prevention have been described. However, the same structure is applied to the square drive portion and the socket engaging portion of the anvil of the impact wrench. You may distribute it. In that case, it becomes possible to prevent biting of the socket.

DESCRIPTION OF SYMBOLS 1 ... Impact driver, 2 ... main body housing, 3 ... hammer case, 4 ... motor, 5 ... inverter circuit board part, 6 ... control part, 7 ... gear mechanism, 8 ... impact mechanism, 9 ... output part

Claims

With the housing,
A motor housed in the housing;
And an output portion rotatably supported by the housing and capable of receiving a driving force of the motor and rotating around a rotation axis.
The output unit includes a hole into which a tip tool can be inserted, and a regulating member that regulates relative movement between the tip tool and the output unit.
The hole has a plurality of abutments and a plurality of recesses, and the plurality of abutments project radially inward of the output portion and abut on a plurality of side surfaces of the tip tool. The relative rotation between the tip tool and the output portion is restricted, and the plurality of recessed portions are located between the adjacent contact portions adjacent to each other in the rotational direction of the output portion and are separated from the plurality of corner portions of the tip tool As described above, a plurality of accommodation spaces are formed which are recessed radially outward of the output section to accommodate a plurality of the corner sections,
The restriction member is disposed at a position overlapping any one of the plurality of corner portions,
In a state in which the tip tool is inserted into the hole, a region in which the contact portion does not abut the side surface is larger than a region in which the contact portion abuts the side surface. .
Each of the plurality of contact portions has a plurality of contact surfaces that contact each of the plurality of side surfaces,
The angle formed by the two virtual straight lines when connecting the rotation axis and the upstream end and the downstream end of each of the plurality of contact surfaces in the rotation direction of the output unit is the rotation axis and the output. The angle according to claim 1, characterized in that it is smaller than the angle formed by the two imaginary straight lines when connecting the downstream end and the upstream end adjacent to each other with respect to the adjacent contact surface in the rotational direction of the part. Electric tool.
The electric power tool according to claim 1 or 2, wherein inflection points exist on both sides of the plurality of contact portions in the rotational direction of the output portion in a cross section orthogonal to the rotation axis.
The power tool according to claim 3, wherein the recess defines a plurality of the accommodation spaces by the presence of the inflection point.
The distance from the straight line connecting the inflection points located on both sides in the circumferential direction of each of the plurality of abutting portions to the projecting end of the abutting portion is located on each side in the circumferential direction of each of the plurality of recessed portions The power tool according to claim 3 or 4, wherein the power tool is smaller than a distance from a straight line connecting the inflection points to the concave end of the recess.
With the housing,
A motor housed in the housing;
And an output portion rotatably supported by the housing and capable of receiving a driving force of the motor and rotating around a rotation axis.
The output unit includes a hole into which a tip tool can be inserted, and a regulating member that regulates relative movement between the tip tool and the output unit.
The hole has a plurality of abutments and a plurality of recesses, and the plurality of abutments project radially inward of the output portion and abut on a plurality of side surfaces of the tip tool. The relative rotation between the tip tool and the output portion is restricted, and the plurality of concave portions have surfaces facing orthogonal to the radial direction of the output portion and facing the plurality of corner portions of the tip tool, and the rotation of the output portion A plurality of housing spaces that are recessed outward in the radial direction of the output portion so as to be spaced apart from the plurality of corner portions of the tip tool, positioned between adjacent abutment portions with respect to the direction to accommodate the plurality of corner portions. Define
The electric tool according to claim 1, wherein the restriction member is disposed to overlap with any one of the plurality of side surfaces.
At least a portion of the tip tool has a polygonal shape,
The polygonal shape is a hexagonal prism shape,
The plurality of contact portions are six contact portions,
The plurality of sides are six sides,
The power tool according to any one of claims 1 to 6, wherein the six abutment portions abut on the six side surfaces, respectively.
The hexagonal column shape is a regular hexagonal column shape,
The power tool according to claim 7, wherein the plurality of abutment portions abut on central portions of the six side surfaces.
The restriction member is movably provided between a first position and a second position closer to the rotation axis than the first position in the radial direction of the output portion, and is positioned at the first position. The relative position between the tip tool and the output portion is allowed when the tip tool is inserted into the hole, and the tip tool is inserted into the hole when the tip tool is positioned at the second position. The electric tool according to any one of claims 1 to 8, wherein relative movement between the tip tool and the output unit is restricted in a state.
The electric power tool according to any one of claims 1 to 9, wherein the restriction member is a steel ball.
The electric tool according to any one of claims 1 to 10, wherein the concave portion and the abutting portion adjacent to each other are connected with a predetermined curvature.
With the housing,
A motor housed in the housing;
And an output portion rotatably supported by the housing and capable of receiving a driving force of the motor and rotating around a rotation axis.
The output unit includes a hole into which a tip tool can be inserted, and a regulating member that regulates relative movement between the tip tool and the output unit.
The hole has a plurality of abutments and a plurality of recesses, and the plurality of abutments project radially inward of the output portion and abut on a plurality of side surfaces of the tip tool. The plurality of recessed portions are positioned between the adjacent contact portions adjacent to each other with respect to the rotation direction of the output portion, and restrict a relative rotation between the tip tool and the output portion, and a plurality of cross sections orthogonal to the rotation axis The angular portion is depressed radially outward of the output portion so as to be separated from a plurality of corner portions of the tip tool by the presence of inflection points on both sides of the contact portion in the rotational direction of the output portion. Define multiple storage spaces to be stored,
The restriction member is disposed at a position overlapping any one of the plurality of corner portions,
The distance from the straight line connecting the inflection points located on both sides in the circumferential direction of each of the plurality of abutting portions to the projecting end of the abutting portion is located on each side in the circumferential direction of each of the plurality of recessed portions An electric power tool characterized by being smaller than a distance from a straight line connecting the inflection points to the concave end of the concave portion.
The power tool according to claim 3 or 12, wherein a curve is connected to the inflection point.