JP7434721B2 - Electric tool - Google Patents

Description

TECHNICAL FIELD The present invention relates to a power tool that is protected against impact caused by dropping or the like.

Among hand-held power tools, cordless power tools that are driven by electrical energy stored in a battery are widely used. 2. Description of the Related Art In power tools in which a tip tool such as a drill or a screwdriver is rotationally driven by a motor to perform a required work, a battery is used to drive the motor, as disclosed in Patent Document 1, for example. The rotational force of the motor is converted to rotational motion of the output shaft via the power transmission mechanism, thereby rotating the tip tool. Such a power tool is disclosed in Patent Document 1, for example.

In a power tool such as that disclosed in Patent Document 1, a handle portion is formed that extends from approximately the center of the body portion in a direction substantially orthogonal to the axial direction, and the tip of the handle portion is located at a position away from the body portion (apart from the body portion). A battery mounting part is provided at the end of the battery. The battery attachment part extends in a direction crossing the axis of the handle part, and a pack-type battery is attached to the lower side of the battery attachment part. A control circuit board for controlling the motor is provided inside the battery attachment part. Further, a switch panel is arranged on the upper surface of the battery mounting part. The switch panel includes soft-touch buttons for setting the rotational speed of the motor and the strength of the blow, a lighting switch for a lighting device provided near the output shaft, and the like.

Japanese Patent Application Publication No. 2014-124725

With hand-held power tools, there are cases where the power tool falls to the ground or the like due to the operator's carelessness. For this reason, manufacturers of power tools have taken measures to prevent the impact of a fall so that they will not break as much as possible. There are various parts that are subject to impact when dropped, but in the process of taking measures against impact, the inventors found that, for example, in the case of a battery-powered power tool, the power tool 1, with the battery on the bottom, was moved from its normal working position. It has been found that when dropped from a high position, the vicinity of the base of the handle part and the battery mounting part may deform, causing damage to the control circuit board located below. The amount of deformation near the connection between the handle part and the battery mounting part becomes particularly large when an opening is provided near the top surface of the part where the battery mounting part extends to place the switch panel. I also understood. In addition, some power tools that use commercial power instead of cordless power tools have a housing section at the end of the handle that houses the circuit board, and the housing section deforms when the power tool is dropped. There is a risk that the circuit board may be damaged. In particular, when the accommodating part or the battery mounting part is provided so as to protrude radially beyond the handle, and the circuit board is disposed over the protruding part from the longitudinal extension of the handle, deformation of the accommodating part may cause There is a high possibility that the circuit board will be damaged.

The present invention has been made in view of the above background, and its purpose is to provide a power tool that significantly reduces the risk of damage to the circuit board due to deformation of the housing when the power tool is dropped on the ground or the like. There is a particular thing.
Another object of the present invention is to provide a power tool that protects a circuit board held between the split-type housing from local deformation of the housing during a fall impact.
Still another object of the present invention is to provide a power tool that effectively protects the circuit board housed in the board case from being damaged by a drop impact by changing the structure of the board case that houses the circuit board. It is about providing.

Representative features of the invention disclosed in this application are as follows.
According to one feature of the present invention, the present invention includes a motor, a body portion housing the motor, a handle portion held by an operator, and an electronic component provided at an end portion of the handle portion and protruding radially from the handle portion. an accommodating part for accommodating a board on which the board is mounted, and the board is accommodated in the accommodating part from a position on an extension of the handle part to a protruding part of the accommodating part, and the board is moved in an orthogonal direction. A support part is provided to directly or indirectly support the This support section is configured integrally with a housing section that accommodates the substrate. Further, the support portion was provided approximately at the center of the housing portion, and a through hole through which the support portion penetrated was provided in the substrate. Further, a step is provided in the center of the support portion, and the lower surface of the substrate is supported by the step. The support part has multiple steps, and screws are arranged vertically at the top of the steps.

According to another feature of the present invention, the left and right edges of the substrate are held in a non-contact state with the accommodating portion. Further, a step portion or a support portion that supports the lower front edge of the substrate is provided in front of the accommodating portion. A gap is provided between the substrate and the screw when viewed in the radial direction of the screw. Further, a switch panel forming an operation surface of the switch element is arranged on the upper side of the substrate, and fixing tabs extending from the switch panel are held by screws. An opening is formed in the radially projecting portion of the handle portion at a position facing the substrate, and the support portion suppresses deformation of the edge of the opening.

According to still another feature of the present invention, the present invention includes a housing, a motor housed in the housing, a power transmission mechanism that transmits rotational force of the motor to the tip tool, and a control unit that controls rotation of the motor. has a handle part and a battery mounting part formed at the tip thereof, the battery mounting part has an extension part extending in a direction intersecting the axial direction of the handle part, and the housing is of a type that is held between the left and right sides. An opening is formed in the extending part so as to straddle the sandwiched dividing plane in a plane intersecting the axial direction, and a battery is mounted on the side of the extending part opposite to the handle part. The power tool having such a configuration has a control circuit board that mounts a control unit inside the extension part and between the battery and the handle part, and the control circuit board is held between the two-part housing. A support portion is provided that directly or indirectly holds the control circuit board in a direction orthogonal to the dividing plane. This support portion is provided at a position that overlaps a part of the peripheral edge of the opening when viewed in the longitudinal direction (B1 direction) of the handle portion.

According to still another feature of the present invention, the control circuit board is housed in a container-shaped board case in which a convex part is formed on the side in the dividing direction of the two-part housing, and the convex part of the board case is connected to the housing. It is held by being pinched by a recess formed in the inner wall. The support part is formed so as to be in contact with the board case, and can be formed as a linear beam part extending in the dividing direction on the lower surface of the board case. The beam portion is preferably formed integrally with the housing, and a portion of the peripheral edge of the opening portion and a portion of the beam portion are provided at a position overlapping in the longitudinal direction (B1 direction) of the handle portion. Here, it is preferable that the length of the beam portion be larger than the width of the control circuit board. Further, the substrate case may be configured to have a pillar portion extending from the bottom surface to the upper opening, and a through hole for passing the pillar portion through the control circuit board.

According to still another feature of the present invention, in the power tool in which the opening is formed in the extending portion of the battery mounting portion of the housing so as to straddle the dividing surface, the control circuit board has a convex portion on the side in the dividing direction. The control circuit board is housed in a container-shaped board case having a top opening larger than the outer edge of the upper surface of the control circuit board, and the beam member is disposed so as to straddle the top opening of the board case. The beam member is composed of an elongated metal plate or metal rod. In addition, a battery terminal part is formed between the control circuit board and the battery to hold a group of device-side terminals for connection with the terminal part of the battery, and the beam member is formed by a convex part formed on the battery terminal part. The support portion is provided at a position overlapping a part of the peripheral edge of the opening when viewed in the longitudinal direction (B1 direction) of the handle portion.

According to still another feature of the present invention, there is provided a body section that houses the motor, a handle section that is held by the operator, and an electronic component that is provided at an end of the handle section and protrudes from the handle section in the radial direction. an accommodating part for accommodating the board, the board is accommodated in the accommodating part from an extended position of the handle part to a protruding part of the accommodating part, and the protruding part of the accommodating part has an opening at a position facing the board. A support portion is provided in the storage portion to suppress deformation of the edge of the opening. Further, the substrate is accommodated in the accommodating portion so as to face the edge, and the support portion is configured integrally with the accommodating portion so as to support the substrate on the opposite side of the edge. Furthermore, the board has a first surface (upper opening surface) facing the edge and a second surface (bottom surface) opposite to the edge with respect to the first surface, and the board is housed in the board case. It is stored in the storage section. The support portion extends from the second surface side to the first surface side of the substrate through the substrate, or extends from the second surface side to the side opposite to the substrate and comes into contact with a portion fixed to the accommodating portion. It is installed in the board case. The substrate may be accommodated in the accommodating portion so as to face the edge, and another support portion may be provided between the edge and the substrate. The accommodating part has a terminal holder that constitutes a battery mounting part for attaching the battery and is provided with a tool-side terminal that connects to the battery-side terminal of the battery, and the terminal holder has an edge of the terminal holder that is connected to the battery-side terminal of the battery. The terminal holder may be provided so as to face the substrate on the opposite side, and the support portion may be provided on the terminal holder.

According to still another feature of the present invention, there is provided a body section that houses the motor, a handle section that is held by the operator, and an electronic component that is provided at the end of the handle section and protrudes from the handle section in the radial direction. The board is accommodated in the housing part from an extended position of the handle part to a protruding part of the housing part, and the protruding part of the housing part has an opening at a position facing the board. It is formed. Here, a sufficient gap was provided between the edge of the opening and the substrate so that even if the edge of the opening was deformed by the impact of the drop, it would not come into contact with the substrate.

According to the present invention, when a shock such as a fall is applied to the housing of a power tool, even if a specific part of the housing is deformed and a pressing force due to the deformation is applied to the circuit board, the circuit board is not disposed on the circuit board. Since deformation of the circuit board is suppressed by the beam-shaped reinforcing portion , failure of the power tool due to damage to the circuit board can be effectively suppressed. In addition, the reinforcing part extends in the direction perpendicular to the housing dividing surface and is made of a metal plate or resin member that connects the two sides of the board case in the direction perpendicular to the dividing surface , so all you need to do is change the board case. The present invention can be easily carried out in the following manner.

FIG. 1 is a right side view of a power tool 1 according to an embodiment of the present invention. 1 is a longitudinal sectional view showing the internal structure of a power tool 1 according to an embodiment of the present invention. (A) is a partially enlarged cross-sectional view of the battery mounting portion 2c in FIG. 2, and (B) is a diagram for explaining the position of the maximum deformation point of the housing and the positional relationship of the support portion (when stationary) when viewed in the front-rear direction. (C) is a diagram for explaining the position of the maximum deformation point of the housing and the positional relationship between the support portion (when an impact occurs) when viewed in the front-rear direction. 3 is a cross-sectional view taken along the line AA in FIG. 3, and (B) is a diagram for explaining the position of the maximum deformation point of the housing and the positional relationship (when stationary) with the beam member 40 serving as the support section when viewed in the left-right direction. (C) is a diagram for explaining the position of the maximum deformation point of the housing and the positional relationship between the support portion (when an impact occurs) when viewed in the left-right direction. FIG. 4 is a perspective cross-sectional view taken along the line BB in FIG. 3; FIG. 4 is a partially enlarged cross-sectional view of the same battery mounting portion 2c as in FIG. 3(A), showing a deformed state when an impact is applied by dropping the battery in an upright state. 7 is a sectional view taken along line CC in FIG. 6. FIG. FIG. 4 is a top view showing the outer shape of an extension of the battery attachment part 2c, and a diagram showing the detailed shape of the switch panel 46. FIG. FIG. 7 is a partially enlarged cross-sectional view of a battery mounting portion according to a second embodiment of the present invention. FIG. 7 is a partially enlarged cross-sectional view of a battery mounting portion according to a third embodiment of the present invention. 11 is a sectional view taken along the line DD in FIG. 10. FIG. FIG. 7 is a partially enlarged cross-sectional view of a battery mounting portion of a housing 2A according to a fourth embodiment of the present invention. 13 is a sectional view taken along line EE in FIG. 12. FIG. FIG. 7 is a partially enlarged cross-sectional view of a battery mounting portion according to a fifth embodiment of the present invention. 15 is a sectional view taken along line FF in FIG. 14. FIG. FIG. 7 is a partially enlarged cross-sectional view of a battery mounting portion according to a sixth embodiment of the present invention. 17 is a sectional view taken along line GG in FIG. 16. FIG. (A) is a partially enlarged cross-sectional view of the battery mounting portion 202c of a conventional impact tool, and (B) is a diagram showing the position (when stationary) of the maximum deformation point (specific portion 234) of the housing 202 when viewed in the front-rear direction. (C) is a diagram showing the position of the maximum deformation point of the housing 202 and the positional relationship between the support portion (when an impact occurs) when viewed in the front-rear direction. FIG. 18 is a sectional view taken along line HH in FIG. 18, and (B) shows the position of the maximum deformation point (specific portion 234) of the housing 202 when viewed in the left-right direction and the positional relationship between the ribs 238a and 238b (when stationary). FIG. 3C is a diagram showing the position of the maximum deformation point of the housing and the positional relationship between the ribs 238a and 238b (when an impact occurs) when viewed in the left-right direction. It is a perspective view of the control circuit part 130 of the electric tool 101 based on the 7th Example of this invention. 21 is an exploded perspective view of the control circuit section 130 of FIG. 20. FIG. 21 is a perspective view showing how the control circuit section 130 of FIG. 20 is attached to the housing 102. FIG. FIG. 7 is a partially enlarged cross-sectional view of a battery mounting portion 102c of a power tool 101 according to a seventh embodiment. It is a figure of the board case 135 of 7th Example, (A) is a top view, (B) is a sectional view of the KK part of (A), and (C) is L of (A). - It is a sectional view of the L part. 24 is a partially enlarged view of section M in FIG. 23. FIG. (A) is a top view of a control circuit unit 130 of the seventh embodiment, and (B) is a top view of a conventional control circuit unit 230. FIG. 7 is a partially enlarged view of the vicinity of the support portion of the control circuit board 131 according to a modification of the seventh embodiment. (A) is a diagram showing the position of stress transmitted from the maximum deformation point of the housing 102 to the board case 135 in the seventh embodiment, and (B) is a diagram showing the stress transmitted from the maximum deformation point of the conventional housing 202 to the board case 135. FIG. FIG. 7 is a cross-sectional view showing a control circuit section 130 of a power tool according to an eighth embodiment of the present invention, in which (A) is a vertical cross-sectional view passing through the dividing surface of the housing 102, and (B) is a cross-sectional view orthogonal to (A). FIG.

Embodiments of the present invention will be described below based on the drawings. In the following figures, the same parts are denoted by the same reference numerals, and repeated explanations will be omitted. Further, in this specification, the front-back and up-down directions will be described as the directions shown in the drawings.

FIG. 1 is a side view showing the appearance of a power tool 1 according to an embodiment of the present invention. The power tool 1 uses a rechargeable pack-type battery 300 as a power source, uses a motor as a drive source to apply rotational force and striking force to an output shaft 10, and has a driver bit installed in a mounting hole 10a and held by a mounting mechanism 11. Screw tightening, bolt tightening, etc. are performed by intermittently transmitting rotary impact force to a tip tool (not shown) such as a screwdriver. The housing 2 of the power tool 1 includes a substantially cylindrical body portion 2a for accommodating a motor and a power transmission mechanism, and extends from approximately the center of the body portion 2a in a direction approximately perpendicular to the axis A1 (downward). A handle portion 2b for an operator to hold with one hand, and a lower end portion of the end portion of the handle portion 2b located on the opposite side to the body portion 2a (an end portion on the side opposite to the body portion). The battery mounting portion 2c is comprised of three parts. The body portion 2a of the housing 2 is manufactured by integrally molding a synthetic resin material together with the handle portion 2b and the battery attachment portion 2c, and is configured to be divided into left and right halves on a vertical plane passing through the rotating shaft 4 of the motor 3. During assembly, the motor, reduction mechanism, impact mechanism, etc. are assembled into one housing 2 (for example, the left housing), and then the other housing 2 (for example, the right housing) is stacked on top of the other housing 2 (for example, the right housing) and the screw boss of the housing is assembled. A method of tightening with a plurality of screws 29a to 29h is used. A trigger lever 7a is disposed at the upper part of the handle portion 2b so as to protrude to the front side, and a forward/reverse switch for switching the rotation direction of the output shaft 10 between the forward direction and the reverse direction is provided at the rear side of the trigger lever 7a. A switching lever 8 is provided. Among the ends of the handle portion 2b, a battery mounting portion 2c formed to extend in the horizontal direction is formed at a lower end portion located on the opposite side to the body portion 2a (an end portion on the side opposite to the body portion). A battery 300 made of a secondary battery such as a lithium ion battery is removably installed. When removing the battery 300 from the state shown in FIG. 1, the battery 300 is moved forward relative to the power tool body while pressing the latch buttons 301 on both the left and right sides.

A slit-shaped air intake port 17b is formed near the rear end side of the body portion 2a of the housing 2, and an air exhaust port is formed on the front side near the outer periphery of the rotor fan 15 (described later in FIG. 2). A slit-shaped air outlet 17c is formed. A cup-shaped hammer case 5 is provided on the front side of the body portion 2a of the housing 2, and has a through hole 5a formed at its tip to allow the output shaft 10 to pass therethrough. A lighting device 9 using an LED is provided on the lower side near the front end of the hammer case 5.

In addition to being provided with a rail mechanism and a group of connection terminals for mounting the battery 300, the battery mounting portion 2c houses a control circuit board (described later in FIG. 2) therein. The width of the battery mounting portion 2c is approximately the same as the top surface of the battery 300. A first switch panel 46 is provided on the upper surface of the battery mounting portion 2c and in front of the lower end of the handle portion 2b. The first switch panel 46 includes a light switch for lighting up the illumination device 9 to illuminate the object to be tightened by the tip tool, a battery level display switch and a battery level display lamp for displaying the remaining capacity of the battery 300. , strength indicator lamps are arranged to display the strength of the blow. A second switch panel (not shown) is also provided on the left side of the battery mounting portion 2c, and a strength changeover switch (not shown) is provided for adjusting the impact strength (tightening strength). It will be done.

FIG. 2 is a longitudinal sectional view showing the internal structure of the power tool 1 of this embodiment. The motor 3 is housed in a cylindrical body portion 2a of the housing 2, which has a substantially T-shape when viewed from the side. The motor 3 is a DC (direct current) motor without brushes (brush for rectification), and is a brushless DC motor with 4 poles and 6 slots. The motor 3 includes a rotor 3a provided with permanent magnets, and a stator 3b provided with a plurality of phases of armature windings (stator windings) such as three-phase windings. The motor 3 uses the output of a position detection element 13 composed of three Hall ICs to detect the rotor position by detecting the magnetic force of the permanent magnet of the rotor 3a, and converts the DC voltage supplied from a battery or the like into a plurality of semiconductors. It operates by being switched by the switching element 14. The rotating shaft 4 of the motor 3 is arranged concentrically with the axis A1 of the cylindrical body portion 2a, and is supported by the housing 2 by two bearings 16a and 16b on the front and rear sides. A substantially annular inverter circuit board 12 on which three position detection elements 13, six semiconductor switching elements 14, etc. are mounted is disposed on the rear side of the stator 3b. The inverter circuit board 12 is a substantially annular double-sided board having substantially the same diameter as the outer diameter of the motor 3. Six semiconductor switching elements 14 are provided to form an inverter circuit, and switch energization to the stator windings of each phase. As the semiconductor switching element 14, an FET (field effect transistor), an IGBT (insulated gate bipolar transistor), or the like is used. The inverter circuit is controlled by a microcomputer, and the energization timing of the armature windings of each phase is set based on the position detection result of the rotor 3a by the position detection element 13, so that sophisticated rotation control is facilitated.

The hammer case 5 accommodates the deceleration mechanism 20 and the impact mechanism 21 therein, and is provided on the front side of the body portion 2a of the housing 2. The hammer case 5 is manufactured as a single piece of metal, and a through hole 5a for passing the output shaft 10 therethrough is formed in the front portion corresponding to the bottom of the cup shape. A mounting mechanism 11 for mounting or removing a tip tool (not shown) is provided at the tip of the output shaft 10 that projects outside of the hammer case 5.

A rotor fan 15 is installed coaxially with the rotating shaft 4 between the rotor 3a and the bearing 16a. The rotor fan 15 is integrally molded, for example, with a plastic mold, and is a so-called centrifugal fan that sucks air from the inner peripheral side at the rear and discharges it radially outward at the front side. The airflow generated by the rotor fan 15 is taken into the body portion 2a through the air intake port 17a and the air intake port 17b (see FIG. 1) formed in the housing portion around the inverter circuit board 12, and is mainly taken into the body portion 2a. 3a and the stator 3b, and the rotor fan 15 causes the air to flow to the housing 2 from a slit-shaped air outlet 17c (see FIG. 1), which will be described later, formed in the housing portion around the rotor fan 15. is discharged to the outside.

The rotor 3a forms a magnetic path formed by permanent magnets. The stator 3b is manufactured with a laminated structure of annular thin iron plates, and six teeth (not shown) are formed on the inner peripheral side, and an enameled wire is wound around each tooth to form a coil. In this embodiment, the coil has a star connection having three phases: U, V, and W phases.

The handle portion 2b of the housing 2 is a portion to be held by an operator, and is approximately cylindrical along the axis B1, and has a shape suitable for being held with one hand. A trigger switch 7 is disposed inside the handle portion 2b, and various wiring such as lead wires from the control circuit portion 30 to the body portion 2a are accommodated. Since heavy objects such as the motor 3 and the power transmission mechanism (deceleration mechanism 20 and impact mechanism 21) are arranged above the handle part 2b, the strength of the connecting part between the handle part 2b and the body part 2a is sufficient. It is configured so that Similarly, since a heavy object such as a battery 300 is disposed below the handle portion 2b, the connection portion between the handle portion 2b and the battery mounting portion 2c is configured to have sufficient strength. In particular, reinforcement is achieved near the bases 43a to 43d of the connecting portions.

The battery attachment part 2c of the housing 2 has a part that protrudes forward and left and right from an extension of the handle part 2b, and has a function inside thereof to control the speed of the motor 3 by pulling the trigger lever 7a. A control circuit section 30 including a control circuit board 31 (described later in FIG. 3) is housed therein. The control circuit section 30 is electrically connected to the battery 300 and the trigger switch 7 through a plurality of lead wires. Further, the control circuit board 31 is provided with a connector (not shown) for connecting a lead wire (not shown) and the control circuit board 31. Control circuit board 31 is further electrically connected to inverter circuit board 12 via a plurality of lead wires. In the vicinity of the control circuit board 31 and on the upper surface of the battery mounting portion 2c, an input/output operation section is provided for performing input operations and display operations using LEDs and the like. Here, a separate switch panel 46 is provided on the housing 2 as an input/output operation section, and a switch for checking the remaining battery power of the battery 300, an LED display device for displaying the remaining power, and a lighting switch for the lighting device 9 are arranged (Details (described later in Figure 8). The switch panel 46 is fixed firmly or loosely to the control circuit section 30 side, and is held so as to be sandwiched from the dividing direction (left and right direction) by the opening 45 arranged so as to be divided by the dividing surface of the housing 2. be done. The opening 45 is provided in a protruding portion of the battery mounting portion 2c. Note that the battery attachment part 2c corresponds to a housing part that houses the board.

The impact mechanism 21 is provided on the output side of the planetary gear reduction mechanism 20, and includes a spindle 22 and a hammer 24, and is rotatably held by a bearing 18b at the rear end and a bearing 18a at the front end. The speed reduction mechanism 20 and the impact mechanism 21 constitute a power transmission mechanism for driving the tip tool by the motor 3. When the trigger lever 7a is pulled to start the motor 3, the motor 3 starts rotating in the direction set by the forward/reverse switching lever 8, and its rotational force is reduced by the speed reduction mechanism 20 and transmitted to the spindle 22. The spindle 22 is driven to rotate at a predetermined speed. Here, the spindle 22 and the hammer 24 are connected by a cam mechanism, and this cam mechanism includes a V-shaped spindle cam groove 23 formed on the outer peripheral surface of the spindle 22 and a V-shaped spindle cam groove 23 formed on the inner peripheral surface of the hammer 24. It is composed of a hammer cam groove 25 and a steel ball 26 that engages with these spindle cam grooves 23 and 25. The hammer 24 is always urged forward by a hammer spring 27, and when at rest is located at a position separated from the end surface of the anvil 28 by engagement between the steel ball 26 and the spindle cam grooves 23 and 25. Convex portions (not shown) are symmetrically formed at two locations on the opposing rotation planes of the hammer 24 and the anvil 28, respectively.

When the spindle 22 is rotationally driven, the rotation is transmitted to the hammer 24 via the cam mechanism, and before the hammer 24 has made a half rotation, the protrusion of the hammer 24 engages with the protrusion of the anvil 28 and the anvil 28 is rotated. However, when relative rotation occurs between the spindle 22 and the hammer 24 due to the engagement reaction force at that time, the hammer 24 moves toward the motor 3 side while compressing the hammer spring 27 along the spindle cam groove 23 of the cam mechanism. begins to retreat. Then, when the protrusion of the hammer 24 rides over the protrusion of the anvil 28 due to the backward movement of the hammer 24 and the engagement between the two is released, the hammer 24 receives the torque accumulated in the hammer spring 27 in addition to the rotational force of the spindle 22. While being rapidly accelerated in the rotational direction and forward by the action of the elastic energy and the cam mechanism, the hammer spring 27 moves forward by the urging force of the hammer spring 27, and its convex part engages with the convex part of the anvil 28 again, and the anvil 28 is integrated. It begins to rotate. At this time, since a strong rotational impact force is applied to the anvil 28, the rotational impact force is transmitted to the screw via a tip tool (not shown) installed in the attachment hole 10a of the anvil 28. Thereafter, the same operation is repeated, and the rotary impact force is intermittently and repeatedly transmitted from the tip tool to the screw, so that, for example, the screw is screwed into a member to be fastened (not shown) such as wood.

FIG. 3(A) is a partially enlarged sectional view of the battery mounting portion 2c of FIG. 2. FIG. The battery attachment part 2c constitutes an attachment part for attaching the battery 300, and is a part that holds the terminal holder 50, which is provided with a tool-side terminal for connecting to a terminal on the battery 300 side (battery-side terminal). , further functions as a housing section that houses the control circuit section 30. In the control circuit unit 30, a control circuit board 31 on which electronic components such as a microcomputer (not shown), other electronic elements, and connectors are mounted is housed inside a board case 35, which is a dish-shaped container with an opening at the top. The inside of the case 35 is filled with resin 33. The control circuit board 31 has a first surface (top surface) facing the opening 45 and a second surface (bottom surface) opposite to the opening 45 with respect to the first surface. The resin 33 is filled in the substrate case 35 in a liquid state and hardened, and for example, a hardening resin such as urethane is used. Here, by pouring the resin 33 up to the upper end opening of the board case 35, filling the resin, and then curing the resin 33, the upper surface (liquid level) of the resin 33 becomes almost the same as the upper end position of the board case 35, and the control circuit board 31 located inside the board case 35 is completely immersed. The curable resin used here preferably has elasticity that allows for some degree of deformation when subjected to an external pressure load, but the type of curable resin used is arbitrary, and the elasticity The resin may not only be strong, but may also be a resin that becomes hard after curing and has weak or almost no elasticity. The board case 35 is formed by integral molding of synthetic resin such as plastic, and has a small protrusion that is a part of the outer surface of the board case 35 and protrudes in the left-right direction on the side in the dividing direction (left-right direction) of the housing 2. Portions 35a and 35b are formed, and a convex portion 35c that protrudes forward from the front side is further formed. The convex portion 35c has a sufficient length to be continuous in the left-right direction. Further, a recess 35e is formed on the rear bottom surface, and vertical movement is restricted by ribs 39b formed on the inner side wall portion of the housing 2 and extending in parallel in the vertical direction. The board case 35 is stably attached to the housing 2 by being held between the left and right split type housing 2 so that the protrusions 35a to 35c fit into the recesses 38c etc. formed on the inner side wall portion of the housing 2. is maintained. The terminal holder 50 is disposed on the opposite side (lower side) from the opening 45 side when viewed from the control circuit board 31, and is provided so as to face the control circuit board 31.

A soft layer 6 (6c) is formed on the surface of the housing 2 in order to reduce the impact at the time of a collision, to improve the tactile sensation when gripped by an operator, and to provide an anti-slip effect. The soft layer 6 is made of elastomer, for example, and has a two-layer structure so as to cover the entire surface of the synthetic resin housing 2 during injection molding. A beam member 40 extending in the left-right direction and having a flat upper surface is provided on the lower side of the board case 35 . The beam member 40 is provided so as to be in contact with the bottom surface 35d of the board case 35, and is provided at a position in contact with the bottom surface slightly forward of the center when viewed in the front-rear direction. The beam member 40 has a hollow rectangular column shape and is configured to be continuous from the right side to the left side of the battery attachment portion 2c of the housing 2. Also, the beam member 40 is made of synthetic resin like the housing 2, and is molded integrally with the housing 2. A terminal holder 50 is provided on the rear side of the beam member 40 and on the lower side facing the control circuit section 30 in the vertical direction. The terminal holder 50 is a component for holding a plurality of connection terminals (not shown, tool side terminals) for contacting connection terminals (not shown, battery side terminals) of the battery 300 (see FIG. 2), A recess 51a is formed on the front side, and a recess 51b is formed on the rear side, and these are fitted to the protrusions formed on the housing 2 to be attached to the lower surface portion of the battery attachment part 2c. A rail groove 52-2 and a rail portion 53-2 are further formed in the battery mounting portion 2c, and a latch groove 54-2 is formed near the front end of the rail portion 53-2.

FIG. 3(B) shows the position where the load is applied and the degree of deformation of the control circuit section 30 as a model, and shows the position of the maximum deformation point of the housing and the beam member 40 serving as the support section when viewed in the front-rear direction. Shows the positional relationship (when stationary). The shape of the control circuit section 30 is simplified and shown as a rectangle. Here, the reference numeral 34 refers to a specific portion 34 that comes into contact with the control circuit section 30 (particularly the upper surface of the resin 33) when the power tool 1 falls on the floor etc. in an upright state with the battery 300 facing down. This shows the position in the front-rear direction. The specific portion 34 corresponds to the vicinity where the outer edge of the opening 45 intersects with the dividing surface of the housing 2, as indicated by the arrow in FIG. 3(A), and is located near a part of the edge of the opening 45. corresponds to Here, the deformable portion 34 of the housing 2 is at a position separated from the control circuit section 30 by a gap as shown in FIG. 3(B) when no impact is applied, but when the power tool 1 is in an upright state, At the moment of falling and hitting the floor, the strong load 36A applied to the portion 34 via the handle portion 2b causes the portion 34 to move (deform) downward and hit the control circuit portion 30. However, in this embodiment, since the beam member 40 extending in the left-right direction is located on the opposite side of the board case 35 with respect to the direction in which the load 36A is applied, the force of the control circuit section 30 that is about to be deformed is absorbed by the beam member 40. It will be supported from below like the power of 41. The portion 34 is located above the control circuit section 30 and faces the control circuit section 30 (which holds the control circuit board 31 via the resin 33). Further, the opening 45 is also located above the control circuit section 30 and faces the control circuit section 30.

Here, for comparison, the shape of the housing 202 of a conventional impact tool will be explained using FIG. 18. FIG. 18(A) is a partially enlarged sectional view of a battery mounting portion 202c of a conventional impact tool. The control circuit section 30 is the same component as shown in FIG. The shape of the housing 202 is the same as that of the housing 2 shown in FIG. 3 except that the beam member 40 is not formed. It is also the same as the housing 2 of FIG. 3 in that an opening 45 is provided above the front side of the control circuit section 30. The board case 35 has a protrusion 35c formed on the front side, which fits into a recess 238c formed in the housing 202. Ribs 239a and 239b (however, ribs 239a are not visible in the figure) extending in parallel in the vertical direction are formed on the inner side wall portion of the housing 2 near the rear side of the board case 35 and in contact with the left and right sides. be done. FIG. 18(B) is a diagram showing the position (at rest) of the maximum deformation part (specific part 234) of the housing 202 when viewed in the front-rear direction, and (C) is a diagram showing the position of the maximum deformation part of the housing 202 as seen in the front-rear direction. FIG. 3 is a diagram showing the positional relationship between the support portion and the support portion (when an impact occurs). When viewed in the front-rear direction, the control circuit section 30 is held by the front recess 238c and the rear ribs 239a and 239b. Further, the specific portion 234 is located between the front recess 238c and the rear ribs 239a and 239b. Here, when a downward force in the direction of the arrow 236 is applied to the specific portion 234 due to a fall of the impact tool, the specific portion 234 deforms and comes into contact with the control circuit portion 30, causing the control circuit portion 30 to contact the recess 238c. It bends downward using the rear ribs 239a and 239b as fulcrums. At this time, upward forces 240a and 240b act from the ribs 239a and 239b in response to the downward force 236. Returning to FIG. 3, when comparing FIG. 3(C) and FIG. 8(C), it is clear that in this embodiment, the beam member 40 vertically coincides with the maximum deformation point (specific portion 234) of the housing 202. Because of this position, deformation of the control circuit section 30 can be effectively suppressed.

FIG. 4(A) is a sectional view taken along the line AA in FIG. 3, showing the shape of the housing 2 of this embodiment. The container-shaped board case 35 has walls on the left and right sides, and two convex portions 35a and 35b are formed at the upper portion so as to protrude in the horizontal direction. The board case 35 has an open surface (first surface) facing a portion 34 of the control circuit board 31 (to be described later), and covers a surface (second surface) opposite to the first surface. Note that since the AA cross-sectional position in FIG. 3(A) is not completely planar, it appears that the lower surfaces of the convex portions 35a and 35b are not in contact with the inner wall surface of the battery mounting portion 2c of the housing 2; As can be seen by comparing the positions taken along the line AA in FIG. 3A, the lower surfaces of the convex portions 35a and 35b actually come into contact with ribs formed on the inner wall surface of the battery mounting portion 2c. The size of the protrusions 35a, 35b in the front and back direction is not comparable to the length of the board case 35, and as shown by the dotted line in FIG. 3(A), the protrusions 35a, 35b are on the front side It is formed only in some parts. This is because the weight of the control circuit board 31 is smaller than other components (motor 3, power transmission mechanism, battery 300), so it does not require much strength unless an excessive impact is applied due to falling. Here, the beam member 40 is formed so as to be located at one location that coincides with the deforming region 34 when viewed in the first direction (front-back direction) of the control circuit section 30 (or the control circuit board 31).

For comparison, the shape of the housing 202 of a conventional impact tool will also be described using FIG. 19. FIG. 19 is a sectional view taken along line HH in FIG. 18. Here, since the beam member 40 is not formed on the lower side of the board case 35, ribs 238a and 238b for holding the protrusions 35a and 35b are formed on the housing 202. On the other hand, the lower side of the bottom surface 35d of the board case 35 is a gap. FIG. 19(B) is a diagram showing the position of the maximum deformation part (specific part 234) of the housing 202 when viewed in the left-right direction and the positional relationship (when stationary) between the ribs 238a and 238b that hold the convex parts 35a and 35b. , (C) are diagrams showing the position of the maximum deformation point of the housing and the positional relationship between the ribs 238a and 238b (when an impact occurs) when viewed in the left-right direction. As can be seen from this figure, when a strong force is applied to a specific portion 234 in the direction indicated by the arrow 236, the control circuit section 30 bends downward. At this time, the portions receiving the force of the arrow 236 are the left and right ends, and their points of action are 141a and 141b.

FIG. 4(B) is a diagram showing the positional relationship (when stationary) between the position of the maximum deformation point of the housing 2 and the beam member 40 serving as the support portion when viewed in the left-right direction. The beam member 40 is composed of a right beam member 40-1 integrally molded with the right side portion of the housing 2, and a left beam member 40-2 integrally molded with the left side portion of the housing 2. 1 and the left beam member 40-2, one side is formed in a concave shape and the other side is formed in a convex shape, so that the concave part and the convex part fit together at the time of joining. Beam members 40-1 and 40-2 are in contact with the bottom surface 35d of the board case 35 so as to be continuous in the left-right direction. This state is shown in FIG. 4(B), and when the power tool is at rest (not in a state of falling impact), the specific part 34 that is easily deformed has a predetermined gap with the control circuit part 30 and is not in contact with the control circuit part 30. in contact. At the moment when the power tool 1 falls in an upright position and hits the floor, a specific part 34 moves downward due to the strong load 36A applied through the handle part 2b, as shown in FIG. 4(C). The control circuit unit 30 is contacted. However, in this embodiment, since the beam member 40 extending in the left-right direction is located on the opposite side of the board case 35 on the extension line of the position where the load 36A is applied, the beam member 40 (40-1 and 40-2) will support it from below in the direction of the force of arrow 41A. Here, when the control circuit section 30 (or control circuit board 31) is viewed in the second direction (left-right direction), the beam members 40 (40-1 and 40-2) are located on the entire left and right sides including the deforming portion 34. was formed. By providing the beam member 40 in this manner, deformation of the control circuit board 31 due to excessive load applied to the control circuit board 31 of the control circuit section 30 can be effectively suppressed. In particular, when comparing the degree of deflection of the control circuit section 30 in FIG. 4(C) and the degree of deflection of the control circuit section 30 in FIG. 19(C), the structure shown in FIG. As you can see, it is significantly less.

FIG. 5 is a perspective sectional view taken along the line BB in FIG. 3. At this cross-sectional position, no convex portions are formed on both left and right sides of the board case 35. Although a microcomputer and other electronic components are mounted on the actual control circuit board 31, illustration thereof is omitted. The left and right sides of the board case 35 are held by walls 37 to prevent the board case 35 from shaking in the left and right direction. Beam members 40 (40-1, 40-2) are provided below the board case 35. Although the beam member 40 is formed into a cylindrical shape that is hollow in the longitudinal direction and cross-sectional shape, it may be a solid beam portion instead of being hollow. Since the right beam member 40-1 is molded integrally with the right battery mounting portion 2c-1, and the left beam member 40-2 is molded integrally with the left battery mounting portion 2c-1, their strength is sufficiently high. The upper surface of the battery 300 is located below the beam member 40, and rail grooves 52-1 and 52-2 are formed on both left and right sides. Rail portions 53-1 and 53-2 that protrude inward are formed below the rail grooves 52-1 and 52-2, respectively. Latch grooves 54-1 and 54-2 for engagement with latch claws are formed on the distal end sides of the rail portions 53-1 and 53-2.

An opening 45 is formed in the upper surface of the battery attachment part 2c so as to intersect the joint surface of the battery attachment parts 2c-1 and 2c-2. The opening 45 is formed to provide a switch panel 46 (see FIG. 1), and is arranged near the front side of the handle portion 2b (2b-1, 2b-2) of the housing 2 rather than near the base thereof. When the opening 45 is provided near the base 43d of the handle portion 2b (2b-1 and 2b-2) and the battery mounting portion 2c (2c-1, 2c-2) in this way, the base 43d of the opening 45 The strength of the nearby portion (specific portion 34) will be lower than that of other portions. When the power tool 1 falls while in an upright position and hits the floor, the battery 300 often hits the floor first, and in that case, the weight from falling heavy objects such as the motor 3 and the power transmission mechanism is applied to the handle portion 2b. Since the load is applied to the battery mounting portion 2c through the load, the specific portion 34 deforms the most due to the load. FIG. 6 shows the state of this deformation.

FIG. 6 is a partially enlarged cross-sectional view of the battery mounting portion 2c, which is the same as that in FIG. As in the present embodiment, the handle portion 2b extending perpendicularly upward is formed from the horizontally extending portion of the battery mounting portion 2c, and the switch panel 46 is provided on the upper surface of the extending portion. (See FIG. 1) When an opening 45 is formed, when receiving an impact due to a fall, the specific portion 34 is pushed downward and deformed. This is because there is a large opening 45 in the battery attachment part 2c of the housing 2, and the part of the opening 45 that is closest to the part where the impact from the handle part 2b is transmitted and is weak in strength will not be deformed. This is because it becomes the largest. As a result, the central rear edge of the opening 45 deforms and sinks downward, as indicated by 34c in FIG. 6, and the portion 34 is pushed into the resin 33. When deformed in this way, a force that bends the control circuit section 30 downward acts. Forces applied to the control circuit board 31 include compressive stress and bending stress, but the possibility of the board cracking is higher when bending stress is applied than when compressive stress is applied. When bending stress is applied to a portion near the center of the control circuit board 31, there is a high risk of damage. Therefore, if a portion near the center of the control circuit board 31 is bent by the impact when the power tool 1 is dropped, it may break. On the other hand, in this embodiment, the beam member 40 is formed below the board case 35 and directly under the specific portion 34, so even if stress is applied to the specific portion 34, the control circuit portion 30 cannot be bent. Since such deformation is suppressed, damage to electronic components mounted on the control circuit board 31 due to bending of the control circuit board 31 can be effectively suppressed.

FIG. 7 is a sectional view taken along the line CC in FIG. 6, and shows the state of impact when the impact is applied when the device is dropped while standing upright. The specific part 34 that deforms due to the impact is near the joint surface of the left-right split type housing 2, and as shown in FIG. ). Here too, since the beam members 40 (40-1, 40-2) are arranged below the deformable part 34 and below the board case 35, the control circuit part 30 is deformed (part 34) is suppressed, and the bending force applied to the control circuit board 31 can be suppressed.

FIG. 8 is a top view showing an extension of the battery attachment part 2c, and is a diagram showing the switch panel 46. As shown in FIG. The shape of the outer edge near the base of the handle portion 2b is approximately circular, and extending portions are formed that extend in a planar manner from the vicinity of the base on the front side, the right side, and the left side. The switch panel 46 is arranged approximately at the center of the extending portion extending forward. The switch panel 46 is placed in an opening 45 formed in the housing 2, but if the board case 35 housing the control circuit board 31 is placed directly under the opening 45, it will be easier to wire and assemble. is also advantageous. The switch panel 46 is made of synthetic resin, and is provided with soft-touch switches and lighting means. The light switch 47 is a switch that sets the irradiation mode of the lighting device 9, and has two modes: a continuous irradiation mode in which the light is turned on for a certain period of time (for example, 2 minutes) regardless of whether or not the trigger lever 7a is operated; There is a switch-linked irradiation mode in which the light is turned on and turned off in a short time (for example, 10 seconds) when the trigger lever 7a is released. Each time the light switch 47 is pressed, the mode changes from continuous irradiation mode to switch-linked irradiation mode to light-off. In continuous irradiation mode, LED 48a lights up, in switch-linked irradiation mode, LED 48b lights up, and lighting device 9 turns off. At this time, neither of the LEDs 48a and 48b lights up. On the right side of the switch panel 46, only a logo is displayed and no other switches are provided. However, a switch and a plurality of LEDs may be provided to check the remaining amount of the battery, or a tightening mode changeover switch and a plurality of LEDs may be provided to switch the tightening mode. The switch panel 46 is manufactured as a separate component from the housing 2, and is fixed so as to be connected to the control circuit board 31, and the outer edge portion of the switch panel 46 is held between the opening 45 of the split housing 2. Ru.

In FIG. 8, the area surrounded by an ellipse is a specific portion 34 that is likely to be deformed by the impact of a fall. On the other hand, the position where the beam member 40 is provided is the position shown by the dotted line. When the specific portion 34 is viewed from above in FIG. 8, it can be seen that the specific portion 34 is located within the internal region of the beam member 40. Further, since the area occupied by the beam member 40 indicated by the rectangular dotted line is positioned so as to partially overlap with the area occupied by the switch panel 46, this serves as a countermeasure against shock to a specific part 34 when the switch panel 46 falls. When the panel 46 is operated, the influence of the pressing force applied to the switch panel 46 extends to the control circuit section 30, and the load that tends to deform the control circuit board 31 can be effectively counteracted. In this way, when a part of the housing 2, particularly a specific portion 34, is deformed due to a fall of the product, it is possible to prevent the control circuit board 31 from being pushed in by the housing 2 and being damaged.

As explained above, in this embodiment, a beam member 40 is formed on the inner side of the battery mounting portion 2c of the housing 2 and extends in a direction perpendicular to the dividing plane, and the beam member 40 is formed on the inner side of the battery mounting portion 2c of the housing 2. Since the bottom surface 35d (second surface side of the control circuit board 31) is held, the possibility of damage to the control circuit board 31 when the power tool 1 is accidentally dropped is greatly reduced. be able to. Furthermore, the beam member 40 can be formed by simply changing the injection molding mold of the housing 2, and the control circuit board 31 and the board case 35 can remain in their conventional shapes, making it easy to apply the present invention. be. In particular, the control circuit section 30 is disposed from the handle section 2b to the protruding portion of the battery mounting section 2c (accommodating section) that protrudes in the radial direction from the handle section 2b, that is, on both front and rear or left and right sides with respect to the section 34. This is effective in a configuration in which the battery is supported by the battery mounting portion 2c. This is because in a configuration in which the control circuit section 30 is housed (supported) only in the protruding portion, there is little possibility that the control circuit section 30 will bend even if the control circuit section 30 is pushed by the portion 34 .

FIG. 9 is a partially enlarged sectional view of the vicinity of the control circuit board 61 of the housing 2 according to the second embodiment of the present invention. The second embodiment has the same structure as the first embodiment in that a beam member 40 is formed on the housing 2, but in addition to forming the beam member 40, a bottom surface 65d is formed on a part of the board case 65. A column portion 65e extending upward from the second surface of the control circuit board 61 is formed. The pillar portion 65e is formed directly below a specific portion 34 that is easily deformed by impact when dropped, and a cylindrical or prismatic member is formed upward to near the specific portion 34 by penetrating the control circuit board 61. Extends to. The height of the pillar portion 65e is set at the same position or approximately the same position as the upper opening surface of the board case 65. The pillar portion 65e, like the board case 65, is formed by integral molding of a non-conducting synthetic resin. The shape and structure of the pillar portion 65e of the board case 65 are similar to the board case 35 of the first embodiment except that a through hole 61a is provided. Convex portions 65a and 65b (65a is not visible in FIG. 9) are formed on both left and right sides of the front, and a convex portion 65c is formed on the front edge. In addition, a through hole 61a is formed in the control circuit board 61 to vertically penetrate the pillar portion 65e. The shape of the through hole 61a should be appropriately sized to allow the column 65e to pass through and to position the control circuit board 61 within the board case 65. Here, there is almost no gap between the through hole 61a and the column 65e. There should be no gaps, but there may be gaps. The periphery of the control circuit board 61 housed in the board case 35 is filled with a curable resin 63. Since the curable resin is a material that does not conduct electricity and is a smooth liquid when filled into the board case 35, it can be filled into every corner of the inside of the board case 35 without any gaps. Note that the column portion 65e may extend downward from the bottom surface 65d of the board case 65 (the second surface side of the control circuit board 61).

With the above configuration, when the specific portion 34 attempts to deform due to the impact of the fall, as shown in FIGS. 6 and 7, the portion 34 comes into contact with the upper surface of the column portion 65e. The column portion 65e is a member extending in the vertical direction, and a beam member 40 is provided on the lower side of the board case 65 on an extension of its longitudinal axis to receive the load at the time of impact. In particular, when viewed in a cross-sectional view as shown in FIG. 9, the portion 34, the column 65e, and the beam member 40 are arranged vertically, so that the load that tends to deform during an impact is absorbed by the column 65e and the beam. It can be firmly received by the member 40, and strong bending force or compressive force can be prevented from being applied to the control circuit board 61.

FIG. 10 is a partially enlarged sectional view of the vicinity of the control circuit section 70 of the housing 2 according to the third embodiment of the present invention. The third embodiment has the same structure as the first embodiment in that a beam member 40 is formed in the housing 2, but a beam-shaped reinforcement is provided extending from the left side to the right side of the outer edge of the opening of the board case 75. A member 76 was provided. The reinforcing member 76 is made of a highly rigid member such as an elongated iron plate or a stainless steel plate, which is pressed to increase its strength, and is then subjected to projection processing so as to be continuous in the longitudinal direction.

FIG. 11 is a sectional view taken along the line DD in FIG. Recesses 75e and 75f are formed at two locations on the opening edge of the board case 75, and both ends of the reinforcing member 76 are positioned in the recesses 75e and 75f. Furthermore, when a downward deformation load is applied from a specific portion 34 near the center of the reinforcing member 76, the deformation portion contacts the center portion 76a of the reinforcing member 76, so that the deformation load is applied to the control circuit board 31. Direct participation can be effectively suppressed. The material of the reinforcing member 76 is not limited to metal such as iron, but may also be made of resin having high bending rigidity such as carbon, or other materials with high strength. In addition, one or more bar materials may be used instead of a plate material. After the control circuit board 31 carrying components is housed inside the board case 75, the reinforcing member 76 is properly positioned in the recesses 75e and 75f, and the reinforcing member 76 is inserted into the board so that the parts excluding the upper surface of the reinforcing member 76 are filled. A hardening resin 73 is poured into the case 75 . Since the curable resin 73 also has adhesive properties, the reinforcing member 76 is stably held without wobbling by the cured resin 73.

In the example of FIG. 10, the housing 2 on which the beam member 40 of this embodiment is formed is used, but the third embodiment Alternatively, only the reinforcing member 76 may be added. Even with this configuration, compared to the conventional housing 202, the effect of protecting the control circuit board 31 from impact when dropped can be sufficiently obtained.

FIG. 12 is a partially enlarged sectional view of the battery mounting portion 2c of the housing 2A according to the fourth embodiment of the present invention. The shape of the housing 2A is almost the same as the conventional housing 202 (see FIGS. 18 and 19), and the beam member 40 is not formed. However, by increasing the vertical dimensions of the battery mounting portion 202c and ensuring sufficient clearance 237 below the specific portion 234, the specific portion 234 may be damaged due to the impact of the fall as shown in FIGS. 6 and 7. Even if the deformed portion is deformed, the deformed portion is prevented from contacting the control circuit portion 30, or even if the deformed portion is contacted, the applied force is not increased. Even if the structure is such that the stress caused by the deformation of the specific portion 234 is not directly transmitted to the control circuit section 30 by providing a gap in this way, the control circuit board 31 can be prevented from being damaged by the impact when dropped. It can be prevented.

FIG. 13 is a sectional view taken along line EE in FIG. 12. It can be understood from this figure that the gap 237 is sufficiently formed. The disadvantages of the fourth embodiment are that the shape of the battery attachment portion 202c of the housing 202 must be changed slightly, and that the dimensions of the housing 202 are slightly increased in the vertical direction. However, it can be said that the fourth embodiment is easy to apply since it is only necessary to apply it when changing the design of the housing 202. Rather than using the configuration of the fourth embodiment alone, it is better to use it in combination with the control circuit sections 30, 60, and 70 of the first to third embodiments.

FIG. 14 is a partially enlarged sectional view of the vicinity of the control circuit section 80 of the housing 2B according to the fifth embodiment of the present invention. In the fifth embodiment, the control circuit section 80 is substantially the same as that used in the first embodiment, but instead of forming the beam member 40 on the housing 2B side, it is integrated with the terminal holder 55 side. It was formed. Furthermore, since the terminal holder 55 is configured to receive the load upon impact, the mounting rigidity of the terminal holder 55 to the housing 2B is greatly increased. Furthermore, a plurality of ribs 86a, 86b, 87a, and 87b for firmly holding the terminal holder 55 are provided on the inner wall side of the battery attachment portion of the housing 2B. The terminal holder 55 is a member for fixing a plurality of terminals 57a, 57b, etc. that are engaged with the connection terminals of the battery 300, and is made of metal plate-like members (terminals 57i, 57g) made of a nonconductor such as synthetic resin. etc.) into the base portion 56. When the battery 300 is installed or removed, a strong force is applied to the terminal holder 55 in the front and back direction, so a pair of ribs 86a and 86b that extend continuously in parallel in the left and right direction The terminal holder 55 is held so that its rear side (projection 55d) is sandwiched between a pair of ribs 87a and 87b that extend continuously in parallel in the left-right direction. Furthermore, an abutting rib 55f is formed below the rear side of the terminal holder 55, and abuts against a rib 87c on the inner wall of the housing 2B. A support portion 58 that protrudes upward is formed on the upper surface side of the terminal holder 55 . The support portion 58 performs the same function as the beam member 40, and can receive the load applied to the control circuit portion 80 when a fall impact is applied to the specific portion 234. In the fifth embodiment, by changing the shape of the terminal holder 55, it is possible to realize a power tool 1 that is protected against impact when dropped.

FIG. 15 is a sectional view taken along line FF in FIG. 14. A total of nine terminals 57a to 57i are provided on the base of the terminal holder 55. Terminals 57a and 57b are positive terminals for discharging. The partition plate 57c is a non-conductive plate-shaped partition member, and is provided to improve insulation between the positive terminals (57a and 57b) and the other terminals (57d to 57i). The terminal 57d is a T terminal for outputting a signal serving as identification information of the battery 300 to the power tool body or the charging device. The terminal 57e is a V terminal to which a control signal from an external charging device (not shown) is input. The terminal 57f is an LS terminal for outputting battery temperature information from a thermistor (temperature sensing element), not shown, provided in contact with the cell. Terminals 57g and 57h are negative terminals (-terminals). The terminal 57i is an LD terminal that outputs an abnormal stop signal from a battery protection circuit (not shown) included in the battery 300. A support portion 58 extending upward is formed at the FF cross-sectional position of the terminal holder 55 and comes into contact with the lower surface of the board case 85. The support portion 58 is a convex portion that extends continuously in the left-right direction, and its length in the left-right direction is longer than the length of the board case 85 in the left-right direction.

FIG. 16 is a partially enlarged sectional view of the vicinity of the control circuit section 90 of the housing 2B according to the sixth embodiment of the present invention. In the fifth embodiment shown in FIGS. 14 and 15, a support portion 58 that protrudes upward is formed on the terminal holder 55 side, but in the sixth embodiment, the support portion 58 is formed on the lower surface 95d of a container-shaped board case 95. A convex portion 95f that protrudes downward is formed slightly near the front side of the center in the front-rear direction. The rear end of the board case 95 is held by an L-shaped holding portion 87d when viewed from the side. The upper surface of the terminal holder 55A is formed flat. With this configuration, the support function of the board case of the present invention can be realized by simply changing the shape of the board case 95 side without changing the shape of the terminal holder 55.

FIG. 17 is a sectional view taken along line GG in FIG. 16. As shown in this figure, a total of nine terminals 57a to 57i are provided on the base of the terminal holder 55. The assignment of terminals 57a to 57i is similar to the example shown in FIG. 15. In the configuration of this embodiment, the convex portion 95f and the lower surface of the terminal holder 55A are in contact with each other when viewed in the vertical direction of the GG cross section, similarly to the example of FIG. The convex portion 95f extends continuously in the left-right direction, and its length in the left-right direction is longer than the length of the board case 95 in the left-right direction. Note that the terminal holder 55 is a part fixed to the battery mounting part 2c (accommodating part for accommodating a board).

FIG. 20 is a perspective view of a control circuit section 130 of a power tool 101 according to a seventh embodiment of the present invention. The control circuit unit 130 houses a control circuit board 131 on which electronic components such as a microcomputer (not shown), other electronic elements, and connectors (not shown) are mounted inside a board case 135, which is a dish-shaped container with an opening at the top. , a switch panel 150 is provided on the front side of the board case 135. The components mounted inside the board case 135 are basically the same as those in the first embodiment. The outer edge shape of the board case 135 is basically a substantially rectangular shape when viewed from above as in the conventional case, but has a shape (octagonal) in which each corner is cut off diagonally. The substrate case 135 has a tray-like or container-like shape with an opening surface 136 on the upper side, and has a shape that does not leak even when the inside is filled with liquid. The control circuit board 131 has an outer edge shape that follows the shape of the inner wall of the board case 135, and by sandwiching the board case 135 between the right and left parts of the housing 102, the control circuit board 131 can be mounted inside the housing 102. Hold. The surface direction of the control circuit board 131 is in a positional relationship that is perpendicular to the surface direction of the divided surface of the housing 102 . Similar to the first embodiment, the inside of the board case 135 is filled with a curable resin (not shown) and cured. In the first embodiment, the entire outer edge of the control circuit board 131 is fixed at the stepped portion formed on the inner wall surface of the board case 35, but in this embodiment, the entire outer edge is not fixed, but rather The control circuit board 131 is held by a support member formed in a portion near the center.

Two switches 161 and 162 are mounted on the front portion of the board case 135, and a switch panel 150 for forming an operation surface is provided. The switch panel 150 forms an operating section exposed to the outside from the opening 104 of the housing 102 (see FIG. 22, which will be described later), and is manufactured by integral molding of synthetic resin. The switch panel 150 includes a main part located above the opening surface 136 of the board case 135, and a wall part that extends downward from the main part and comes into close contact with the inner wall surface of the board case 135, and a control circuit board. A portion (rib 154, flat plate portion 155) that comes into contact with 131 is formed. The switch panel 150 has a flat upper surface 151 formed on the upper side, and the upper surface 151 has two openings 152a and 152b for enabling the operation of two switches 161 and 162 mounted on the control circuit board 131. It is formed.

FIG. 21 is an exploded perspective view of the control circuit section 130 of FIG. 20. The seventh embodiment differs from the first embodiment in the method of fixing the control circuit board 131 to the board case 135. Further, as in the second embodiment shown in FIG. 9, a support portion (protruding portion 138) extending upwardly through the through hole of the control circuit board 131 is formed in the board case 135. The shape of the board case 135 when viewed from above is almost the same as the shape of the outer edge of the control circuit board 131, and is a tray-like or dish-like container with an opening surface 136 on the upper side, and is integrally molded from synthetic resin with no seams. It is formed as if it were not there. The raised portion 138 extends upward from the bottom surface 134 in a funnel-shaped manner, and is provided slightly forward of the center position when viewed from above.

An annular step portion 138b is formed near the vertical center of the raised portion 138, and a cylindrical portion 138c is formed on the inner peripheral side of the step portion 138b so as to extend upward from the step portion 138b. The conical portion 138a on the lower side of the stepped portion 138b is conical, and has a shape whose diameter increases from top to bottom, and is connected to the bottom surface 134. By forming the conical portion 138a into a funnel shape, stress applied downward from above is reduced. Note that the shape of the conical portion 138a is arbitrary, and as long as the substrate can be held down by the stepped portion 138b, the shape of the conical portion 138a is arbitrary. The upper end of the cylindrical portion 138c becomes a small annular surface 138d, and a thin non-through hole for a screw is formed in the center. The screw 141 is screwed into the hole inside the cylindrical portion 138c, and is tightened until the bottom surface of the head of the screw 141 comes into contact with the annular surface 138d. If a metal self-tapping screw is used as the screw 141, even if a female thread is not previously formed inside the cylindrical portion 138c, as long as there is a prepared hole, the screw itself can be screwed into the cylindrical portion 138c while being tapped.

The switch panel 150 is formed to have the same width as the board case 135, and its front position is approximately the same as the front side wall of the board case 135. The right side edge and the left side edge of the switch panel 150 are formed in a stepped shape, the stepped portion comes into contact with the outer edge of the opening surface 136 of the board case 135, and ribs 153a, 153b are formed below from the stepped portion. A rib 153c extending downward is also formed at the center of the lower front edge of the switch panel 150, and the bottom surfaces of these ribs 153a, 153b, and 153c are in contact with the control circuit board 131, and the switch panel is held horizontally when operating the switch panel. It has the role of keeping the The ribs 153a, 153b, 153c, and 154 allow the control circuit board 131 to abut against the switch panel 150, so that the openings 152a, 152b and the plungers 161a, 162a can be maintained horizontally. On the other hand, the switch panel 150 and the board case 135 are positioned by the contact surfaces of the outer peripheries of the ribs 153a, 153b, and 153c and the board case 135, and the penetration of the screws 141 in the through holes 156. A rib 154 extending downward is formed near the center of the rear edge of the board case 135 in the left-right direction. A tab-shaped flat plate portion 155 extends rearward from the rib 154, and a through hole 156 is formed in the center of the flat plate portion 155. The control circuit board 131, the lower part of the switch panel 150, the ribs 154, and the flat plate part 155 are each bonded to the board case 135 using a curable resin. The through hole 156 has a size that allows the cylindrical portion 138c of the raised portion 138 to pass therethrough.

The upper surface 151 of the switch panel 150 forms a pressing surface for pressing the plungers 161a, 162a of the switches 161, 162, and has two openings 152a, 152b formed therein. An elastic resin film (not shown) is provided on the entire top surface 151 including the two openings 152a and 152b, and the film has button displays indicating the pressed positions of the switches 161 and 162 and transparent LEDs. Windows etc. are printed. In the portion sandwiched between the openings 152a and 152b of the switch panel 150, there are five through holes 152c which are rectangular in top view and are for transmitting light from LEDs (not shown) mounted on the control circuit board 131. , two round through holes 152d are arranged.

The switches 161 and 162 are, for example, tactile switches. By pushing in the plungers 161a and 162a by an operator's operation (push operation), the switch 161 or 162 is turned on. Since the plungers 161a and 162a are biased upward by springs, that is, in a state where the switch is turned off, the switch is turned on when the plungers 161a and 162a are pushed in, and when the pressed state is released, the switch is turned off. It performs a ``momentary movement''. A plurality of (for example, four) terminals (not shown) protrude from the lower sides of the switches 161 and 162 that accommodate the plungers 161a and 162a, and these terminals are fixed to the control circuit board 131 by soldering.

The control circuit board 131 has a first surface (top surface) facing the opening surface 136 and a second surface (bottom surface) on the opposite side. The control circuit board 131 is formed with two through holes 132a and 132b and two rectangular cutouts 132c and 132d. The through hole 132a determines the vertical position of the control circuit board 131 by coming into contact with a stepped portion of a support portion (protruding portion 138) to be described later. The through hole 132a is a hole for passing the screw 142 therethrough. The cutouts 132c and 132d are formed to pass a cable or the like from the lower side to the upper side, but if there is no need to pass the cable or the like, the cutouts 132c and 132d may not be formed.

The board case 135 is formed by integral molding of synthetic resin such as plastic, and has a stepped portion 137 for supporting the control circuit board 131 along the front wall surface. The stepped portion 137 has a height nearly half of the inside height of the board case 135 so that the bottom surface of the control circuit board 131 does not come into contact with the bottom surface 134 of the board case 135 when the control circuit board 131 is installed. do. No step portion is formed in the inner wall portions 135c and 135d on both parallel right sides of the control circuit board 131. Therefore, no downward supporting portion is formed near the right and left edges of the control circuit board 131. The screw 142 passes through the through hole 132b and is screwed into the board case 135. However, a small cylindrical screw boss 139 (not visible in the figure), which will be described later, is formed in the lower part of the through hole 132b.

FIG. 22 is a perspective view showing how the control circuit section 130 of FIG. 20 is attached to the housing 102. Here, only the right side portion of the housing 102 is shown, and the left side portion of the housing 102 is not shown. The board case 135 is held between the left and right housings 102 by being fitted into beams and recesses formed on the inner side wall portions of the housing 102. An opening 120 for fixing the terminal holder 50 (see FIG. 3) is formed on the lower side of the board case 135. As can be seen in this figure, the screw 141 is located at a position passing through the vertical dividing plane of the housing 102, and is placed directly below a specific portion 104 that is most likely to be deformed by the impact of a fall. Further, the lower surface of the specific portion 104 and the screw 141 maintain a non-contact state under normal conditions.

An upper surface 151 of the switch panel 150 fixed to the upper side of the board case 135 is provided so as to be exposed to the outside through the opening 103 of the housing 102. The opening 103 is formed from the right side to the left side of the battery attachment part 102c of the housing 102 so as to straddle the dividing plane. Although the film 160 provided on the switch panel 150 is not shown in FIG. 22, covering the entire top surface 151 with the film 160 can prevent dust and water from reaching the control circuit board 131.

FIG. 23 is a partially enlarged sectional view of the battery mounting portion 102c of the power tool 101 according to the seventh embodiment. FIG. 23(A) is a longitudinal sectional view based on the left and right dividing plane of the housing 102. The board case 135 is arranged perpendicular to the dividing plane of the left-right split type housing 102 and is fixed so as to be sandwiched between the right and left housings 102. The front lower side of the board case 135 is held by a holding surface 121a formed on the inner wall portion of the housing 102. Furthermore, a rib 122 extending in the vertical and horizontal directions is formed near the approximate center of the board case 135 in the front-rear direction. The rib 122 is arranged at a location where local deformation of the housing occurs during a drop impact, that is, near the installation location of the screw 141. Here, the positional relationship is such that the downward projection range of the raised portion 138 partially overlaps the installation range of the rib 122 when viewed from above. With this positional relationship, the ribs 122, which act as beams, can effectively receive a downward impact from the top of the protrusion 138. Note that the rib 122 also serves as a member forming a part of the front edge of the opening 120 formed in the housing 102 for attaching the terminal holder 50 (see FIG. 3). The rear upper part and the rearmost lower part of the board case 135 are not held by ribs and are in a free state. Therefore, when operating the switch panel located on the upper front side of the board case 135, the board case 135 is supported by the housing 102, but if the board case 135 receives a strong impact due to a fall or the like from a power tool, the board case 135 The posture can be changed, which has the effect of reducing deformation occurring in the board case 135 and the control circuit board 131.

In the control circuit board 131, the load at the central portion is supported by a raised part (support part) 138 formed integrally with the board case 135. If a strong load is not applied to the control circuit board 131 during normal use, it is sufficient to hold the control circuit board 131 using only the raised portion 138 and harden it with a curable resin. However, in the case of a power tool, not only an unexpected strong load upon a fall impact but also vibrations applied during operation are transmitted to the control circuit board 131. Therefore, in order to prevent the control circuit board 131 from moving downward with respect to the board case 135, the lower front edge of the control circuit board 131 is held by a stepped portion 137 formed in the board case 135. Furthermore, by fixing the rear end side of the control circuit board 131 with the screws 142, the posture of the control circuit board 131 can be prevented from being disturbed and tilted when the case is filled with the hardening resin. In this way, the control circuit board 131 is always installed in the correct position, and at the same time, it is possible to prevent the switch panel 150 from moving up and down when the switch panel 150 is operated.

A screw boss 139 is formed at the rear left and right center of the board case 135, and the control circuit board 131 is screwed by screwing a screw 142 into the screw boss 139. The screw boss 139 is a cylindrical member and is integrally formed when the board case 135 is injection molded. In this embodiment, the parallel right side edge and left side edge of the control circuit board 131 are free without being supported in the vertical direction. No members that come into contact with the lower surface of the control circuit board 131 are formed on either side of the screw boss 139 . Note that the screw boss 139 is preferably arranged at the center of the left and right sides so as to be on the dividing surface of the housing 102. However, the position where the screw 142 is provided does not have to be exact, and there is no problem even if the screw 142 is slightly shifted from the dividing surface in the left and right direction. Further, in FIG. 23A, the screw boss 139 is arranged near the rearmost end inside the board case 135, but the screw boss 139 may be arranged slightly forward of the rearmost end.

A switch panel 150 is provided on the upper front side of the board case 135. On the upper surface of the switch panel 150, buttons for the operation surface are printed, and a film 160 on which a window for transmitting light from the LED is printed is pasted. The operator can operate the switches 161 and 162 by slightly pressing the button part downward from above the film 160.

The shape of the opening 120 for attaching the terminal holder 50 (see FIG. 3), the shape of the rail groove 52-1, the rail portion 53-1, the latch groove 54-1, etc. are formed the same as in the first embodiment. be done. Upper connection terminals of terminals 57a to 57i (see FIG. 15) fixed to the terminal holder 50 (see FIG. 3) are arranged between the ribs 122 and 124.

FIG. 23(B) is a sectional view taken along line II in FIG. 23(A). The board case 135 is held between the housing 102 by the ribs 121b, the horizontal ribs 106, and the like. The through hole 132a formed approximately at the center of the control circuit board 131 is sufficiently larger than not only the screw 141 but also the cylindrical portion 138c (see FIG. 21 for the reference numeral) of the raised portion 138. Therefore, the vicinity of the center of the control circuit board 131 is not limited in the vertical direction by the screws 141. Further, since the curable resin covering the entire control circuit board 131 has a certain degree of elasticity, the control circuit board 131 can be slightly moved relative to the raised portion 138.

FIG. 24 is a diagram of the board case 135 of the seventh embodiment, in which (A) is a top view, (B) is a cross-sectional view of section KK in (A), and (C) is a cross-sectional view of section KK in (A). FIG. 3 is a cross-sectional view taken along line LL. Three holding parts for holding the control circuit board 131 from below are formed in the inner part of the board case 135. What plays the most important role in this embodiment is the protruding portion 138 provided near the center of the left and right, where a specific portion of the housing 102 that is deformed by the impact of the fall hits the control circuit board 131 for the first time. It is. The raised portion 138 has two roles: one is to define the vertical position of the control circuit board 131, and the other is to make it hit a specific part of the deformed housing 102 and absorb the impact. The purpose is to transmit the signal to the beam portions of the housing 102 (ribs 122 to 124 shown in FIG. 23, etc.) via the board case 135 without being transmitted to the control circuit board 131. A portion of the raised portion 138 below the stepped portion 138b is formed with a conical portion 138a that increases in diameter as it approaches the bottom surface 134, or in the shape of a funnel in the opposite direction. The reason for this conical shape is that the shock applied to the raised portion 138 via the screw 146 is transmitted to the bottom surface 134 in a distributed manner, thereby preventing stress from concentrating on a local part of the board case 135. This is to make it happen. By forming the conical portion 138a, it is possible to suppress a reduction in the mounting area of electronic elements mounted on the lower surface side of the control circuit board 131.

A cylindrical portion 138c is formed above the conical portion 138a. The cylindrical portion 138c serves as a screw boss for fixing a screw. The upper surface of the cylindrical portion 138c becomes an annular surface 138d with a small diameter. The screw 141 is made of metal, and even if a strong impact is applied downward from above, the impact can be transmitted from the raised portion 138 to the bottom surface 134 while effectively dispersing it without destroying the impact area. The portion where this screw 142 is provided is almost directly below the specific portion of the handle portion 102b of the housing 102 that is most easily deformed. Note that the screw 141 is not essential, and the cylindrical portion 138c may be configured to have a cylindrical shape to receive the load without providing the screw 141. Both left and right sides of the control circuit board 131 are in contact with the inner wall surface of the board case 135 or are kept in a non-contact state with a slight distance therebetween. With this configuration, even if a strong downward impact is applied to the top of the screw 141, a direct strong force is not easily applied to the control circuit board 131. Furthermore, even if a strong downward force is applied to the vicinity of the center of the control circuit board 131, the left and right sides of the control circuit board 131 and the board case 135 are not fixed, and the raised portion 138 and the control circuit board Since the control circuit board 131 is not fixed, the control circuit board 131 can slide vertically relative to the deformable board case 135, and unreasonable force is not easily applied to the control circuit board 131.

The vicinity of the front edge of the control circuit board 131 is held with its lower surface placed on the stepped portion 137 . Therefore, although the control circuit board 131 cannot be moved downward, it is possible to move upward. The vicinity of the rear edge of the control circuit board 131 is fixed to the board case 135 by a second screw 142. Therefore, the control circuit board 131 is directly screwed to the control circuit board 131 only by the screws 142 on the rear side. In this way, the control circuit board 131 is screwed in only one place, so even if the control circuit board 131 is deformed at a place other than the screwed place, it can still slide on the board case 135, so the control circuit Stress is not concentrated on a specific location on the board 131, and damage to mounted elements and circuit patterns can be effectively prevented.

Known electronic elements such as a one-chip microcomputer, a resistor, a capacitor, a coil, and a switch are mounted on the upper and lower surfaces of the control circuit board 131. In order to enable double-sided mounting, a predetermined gap is provided between the lower surface of the control circuit board 131 and the bottom surface 134 of the board case 135. Further, a predetermined gap is provided between the upper surface of the control circuit board 131 and the opening surface 136 of the board case 135.

FIG. 25 is a partially enlarged view of section M in FIG. 23. As can be seen from this enlarged view, the height of the cylindrical portion 138c extending upward from the stepped portion 138b is slightly higher than the total height of the control circuit board 131 and the flat plate portion 155 of the switch panel 150. Therefore, the vertical movement of the control circuit board 131 and the switch panel 150 is not completely restricted by tightening the screws 141. Further, the size of the through hole 132a of the control circuit board 131 is sufficiently larger than the size of the cylindrical portion 138c. The screw 141 is made of metal, and has a gap between its top and the specific portion 104 of the housing 102 . Therefore, during normal operation, the housing 102 and the screw 141 maintain a non-contact state, but if the housing 102 falls while still upright, the specific portion 104 deforms downward and comes into contact with the top of the screw 141. do. Although the screws 141 are connected to the board case 135, they are not firmly fixed to the control circuit board 131 and the switch panel 150. That is, although the raised portion 138 restricts the movement of the control circuit board 131 in the front, back, left, right, and up and down directions to some extent, it is not completely fixed to the board case 135. Therefore, it is possible to greatly suppress the application of strong force to the control circuit board 131 due to the deformation of the specific portion 104 of the housing 102 due to the impact of the fall, thereby greatly reducing the risk of damage to the electronic components mounted on the control circuit board 131. Can be reduced.

Although not shown in FIG. 25, the inner space of the board case 135 is filled with a liquid curable resin and cured to remove all or almost all of the electronic components mounted on the control circuit board 131. is covered with resin. It is preferable that the resin be filled to a height from the bottom surface 134 to near the opening surface 136, at least to the extent that the head of the screw 141 is completely hidden.

FIG. 26A is a top view of the control circuit section 130 of the seventh embodiment, and FIG. 26B is a top view of the conventional control circuit section 230. In FIG. 26(A), the screws 141 and 142 and the electronic elements mounted on the control circuit board 131 are not illustrated. Here, a portion (stepped portion 137) of the board case 135 that is in contact with the lower front edge of the control circuit board 131 is shown by a dotted line. In the board case 135, a stepped portion 137a (see also FIG. 21) that is continuous in the left-right direction is formed inside the front edge portion 135a. In addition, although the shape is shaped like a rectangular corner cut diagonally when viewed from above, step portions 137b and 137c are also formed on the inner side of the corner, so that the lower side of the front side of the control circuit board 131 is Hold stably. Note that the front part of the control circuit board 131 and the stepped part 137 may be simply placed on each other without being firmly fixed with screws or the like, or may be connected to ribs 137f and 137g (see FIG. 21) extending in the vertical direction. It is only lightly supported by the weak contact resistance of .

A raised portion 138 that supports the lower surface of the control circuit board 131 is provided near the center of the control circuit board 131 . Here, it is preferable that the raised portion 138 be provided at the left-right center position, and this left-right center position is located at a position passing through the dividing surface of the housing 102. The position of the raised portion 138 when viewed in the front-rear direction is provided slightly in front of the center point. This is to resist the downward force applied to the control circuit board 131 when the switches 161 and 162 disposed on the control circuit board 131 are pressed. Here, an imaginary line 36a connecting the rightmost end position 137d of the stepped portion 137b and the contact point on the rear side of the stepped portion 138b of the raised portion 138, and the leftmost end position 137e of the stepped portion 137c and the rear side of the stepped portion 138b of the raised portion 138 are connected. The plungers of the switch 161 and the switch 162 are respectively included within a pentagonal (approximately triangular) range surrounded by the virtual line 36b connecting the contact points and the stepped portion 137. With this positional relationship, when the switch 161 or the switch 162 is operated, the force applied to the control circuit board 131 can be effectively transmitted to the board case 135, and the contact between the board case 135 and the control circuit board 131 can be prevented. It becomes possible to support the switch panel 150 well in a state where the switch panel 150 is minimized, thereby achieving both a reduction in stress generated in the control circuit board 131 due to deformation of the board case 135 when the board case 135 is dropped, and good operability of the switch panel 150. be able to.

A through hole 132b through which a screw 142 (see FIG. 21) is inserted is formed on the rear side of the control circuit board 131. Furthermore, a screw boss 139 with a screw hole is formed in the board case 135. The screw boss 139 and the through hole 132b are preferably located at a position that coincides with the dividing surface of the housing 102 or at a position close to the dividing surface. Note that the rear side of the raised portion 138 is floating above the board case 135 except for the screw boss 139. Therefore, even if a strong downward impact is received from directly above the screws 141 of the board case 135, the impact will be directly transmitted to the board case 135 via the raised portions 138, so there will be no excessive impact that may distort the control circuit board 131. This has the effect of making it difficult for force to be transmitted. Furthermore, even if a force that causes distortion is applied to the board case 135, it is unlikely to be transmitted to the control circuit board 131, so that the risk of damage to circuit elements mounted on the control circuit board 131 can be effectively reduced.

FIG. 26(B) is a top view of a conventional board case 235 and a control circuit board 231. Although the shape of the control circuit board 231, the shape of the board case 235, and the arrangement of the switches 161 and 162 are not the same, this is a result of matching the shape of the housing. However, the lower surface of the control circuit board 231 is held at the stepped portion 236 around the entire outer edge. Therefore, if a strong downward impact is applied to a specific portion of the housing, most of the force will be received by the entire surface of the control circuit board 231.

The switch panel fixing holes 232a and 232b are holes provided in the control circuit board 131 to fix a conventional switch panel (not shown). In the conventional switch panel, fixing hooks (not shown) are provided from the bottom surface of the switch panel, and the fixing hooks corresponding to the fixing holes 232a and 232b are passed through, and the bottom surface of the control circuit board 131 is hooked with the fixing hooks. Further, the control circuit board 131 is biased toward the fixing hook by an elastic body (not shown) on the upper surface of the control circuit board 131, thereby stably fixing the switch panel. In this way, the conventional board case 235 had the problem of high cost due to the use of elastic bodies, but the present invention uses only the minimum number of screws and hardening resin to fix the switch panel. Therefore, in addition to reducing the stress generated in the control circuit board 131, it is also possible to reduce the number of parts (reducing cost).

FIG. 27 is a partially enlarged view of the vicinity of the support portion of the control circuit board 131 according to a modification of the seventh embodiment. What differs from the shape shown in FIG. 25 is the shape of the raised portion 188 serving as the support portion. The protruding portion 188 is formed such that the conical portion 188a protruding from the bottom surface of the board case 185 and the step portion 188b have the same shape, but the height (axial length) of the cylindrical portion 188c is reduced. The height of the cylindrical portion 188c is set to be higher than the thickness of the control circuit board 131, and the positional relationship is such that the flat plate portion 155 of the switch panel 150 and the control circuit board 131 do not come into strong contact. Also in this modification, there is a slight gap between the specific portion 104 and the upper surface position (opening 186) of the board case 185. Therefore, vibrations transmitted from the housing 102 to the control circuit board 131 during normal operation can be suppressed to a small level.

FIG. 28A is a diagram showing the position of stress transmitted from the maximum deformation point of the housing 102 to the board case 135 in the seventh embodiment. When a strong downward force is applied from a specific portion as indicated by an arrow 148 in FIG. 28(A), the specific portion 104 of the housing 102 is distorted downward and comes into contact with the screw 141. The force applied downward in the axial direction of the screw 141 is transmitted from the board case 135 to the ribs 121 and the like. In this way, the force of the screw 141 is transmitted from the conical portion 138a to the entire board case 135, so that it can be effectively supported by the ribs 121 (ribs 121a, 121b in FIG. 23), ribs 122, etc. as indicated by the arrow 149. Since the ribs 121 to 122 are formed continuously from the right side to the left side of the housing 102, the rigidity can be increased, and the risk of the housing 102 being damaged is reduced.

FIG. 28(B) is a diagram showing the position of stress transmitted from the maximum deformation point of the conventional housing 202 to the board case 135. In the conventional housing 202, a force applied to a specific portion as indicated by an arrow 248 is transmitted to the control circuit board 231, and then to the board case 235 via a step on the lower side of the outer edge of the control circuit board 231. The force applied to the control circuit board 231 is supported by the stepped portion 236 of the board case 235 in the directions of arrows 249a and 249b. In this way, deformation caused by a strong impact such as a fall passes through the control circuit board 231 during the transmission process to the housing 202 at the bottom of the board case 235, so that the electronic elements mounted on the control circuit board 231 are Becomes easily damaged. On the other hand, if the configuration is such that the force is directly transmitted to the housing 202 via the raised portion 138 as shown in FIG. 28(A), the possibility that the control circuit board 231 will be damaged is reduced.

FIG. 29 is a sectional view showing the control circuit section 130 of the power tool 101 according to the eighth embodiment of the present invention, (A) is a vertical sectional view passing through the dividing surface of the housing 102, and (B) is ( It is a longitudinal cross-sectional view orthogonal to A). The eighth embodiment differs from the seventh embodiment in that switches 161 and 162 are not provided in the board case 135A. When the switches 161 and 162 are not provided, the housing 102 is not provided with an opening for the switch unit. Further, it is not necessary to form a step corresponding to the step portion 137 (see FIG. 24) on the inner side of the front wall of the board case 135A as shown in FIG. However, the shape of the board case 135A itself is similar to that of the seventh embodiment, and the vibration transmission path when the specific portion 104 of the housing 102A is deformed downward is also almost the same as the example shown in FIG. 28(A). It will be the same.

The cross-sectional shape of FIG. 29(B) is almost the same as that of FIG. 23(B). In the eighth embodiment as well, the outer diameter of the cylindrical portion 138c is sufficiently smaller than the through hole 132a, so the movement of the control circuit board 131 in the vertical direction is not restricted by the screws 141. However, since the inner space of the board case 135A is almost filled with the curable resin, the control circuit board 131 does not move excessively.

Although the present invention has been described above based on Examples 1 to 8, the present invention is not limited to the above-mentioned examples, and various changes can be made without departing from the spirit thereof. For example, in the above embodiment, an impact tool is used as an example of the power tool 1, but the power tool 1 is not limited to an impact tool, and a battery mounting part is formed at the tip of the handle part, and the battery and circuit board are connected to each other. The present invention can be similarly applied to other battery-powered tools equipped with the following. Furthermore, the invention is not limited to cordless type power tools that are powered by batteries, but can also be applied to corded type power tools that are driven by connecting a power cord to an external power source such as a commercial power source. When applied to a corded type power tool, the lower side of the battery mounting part 2c should be a closed-shaped accommodating part, and the accommodating part should be a split type like the body part and handle part of the housing. An opening surface may be provided to intersect with the opening surface, a switch panel may be attached to the opening surface, and the control circuit sections 30, 60 to 90 may be accommodated inside the housing section.

1 Power tool 2, 2A, 2B Housing 2a Body part 2b Handle part 2c Battery mounting part 3 Motor 3a Rotor 3b Stator 4 Rotating shaft 5 Hammer case 5a Through hole 6 Soft layer 7 Trigger switch 7a Trigger lever 8 Forward/reverse switching lever 9 Lighting Device 10 Output shaft 10a Mounting hole 11 Mounting mechanism 12 Inverter circuit board 13 Position detection element 14 Semiconductor switching element 15 Rotor fan 16a, 16b Bearing 17a, 17b Air intake 17c Air outlet 18a, 18b Bearing
19c to 19j Screw boss 20 Reduction mechanism 21 Impact mechanism 22 Spindle 23 Spindle cam groove 24 Hammer 25 Hammer cam groove 26 Steel ball 27 Hammer spring 28 Anvil 29a to 29h Screw 30 Control circuit section
31 Control circuit board 33 Resin 34 Specific part (of the housing) 35 Board case 35a, 35b, 35c Convex part 35d Bottom surface 35e Recessed part 36A Weight 37 Wall part 38c Recessed part 39a, 39b Rib 40, 40A Beam member (support part)
43a to 43d Near the base (of the handle) 45 Opening 46 Switch panel 47 Light switch 48a, 48b LED
50 Terminal holder 51a, 51b Recessed part 52-1, 52-2 Rail groove 53 Rail part 54 Latch groove 55, 55A Terminal holder 55c, 55d Convex part 55f Rib 56 Base part 57a to 57b, 57d to 57i Terminal 57c Partition plate 58 Support part 60 Control circuit part 61 Control circuit board 61a Through hole 63 Resin 65 Board case 65a, 65b, 65c, 75b Convex part 65d Bottom surface 65e Pillar parts 70, 80, 90 Control circuit part 73, 83 Resin 75, 85, 95 Board Case 75e Concave portion 76 Reinforcement member 85f Convex portion 86a, 86b Rib 87a to 87c Rib 87d Holding portion 95d Lower surface 95f Convex portion 101 Power tool 102 Housing 102b Handle portion 102c Battery mounting portion 103 Opening portion 104 Specific portion (of the housing) 120 Opening Department
121a Holding surface 121b Rib 122 to 125 Rib 125 Step portion 130 Control circuit portion 131 Control circuit board 132a Through hole 132b Through hole 132c Notch portion 134 Bottom surface 135 Board case 135a (Board case) Front edge portions 135c, 135d (Board case) ) Inner wall portion 136 Opening surface 137, 137a to 137c Step portion 137d Rightmost position (of step portion) 137e Leftmost position (of step portion) 137f, 137g Rib 138 Raised portion 138a Conical portion 138b Step portion 138c Cylindrical portion 138d Circle Ring surface 139 Screw bosses 141, 142 Screws 146 Screws 150 Switch panel 151 Top surface 152a, 152b Openings 152c, 152d Through holes 153a, 153b, 154 Rib 155 Flat plate part (tab)
156 penetrating holes 160 film 161, 162A 161a, 162A plunger 185 substrate case 186 opening 186 rising 188A rising part 188a cylindrical portion 188B step part part 202 housing 202B handle installation part 231 control circuit board 232a, 232B Switch Panel fixed Hole 234 (Specific) part 235 Board case 236 Step part 237 Gap 238a, 238b Rib 238c Recessed part 239a, 239b Rib 300 Battery 301 Latch button A1 Axis line B1 (of the motor and output shaft) Center axis line C1 (of the handle part) (of the mounting part) left and right center line (split plane)

Claims (8)

motor and
A housing including a body portion that accommodates the motor, and a handle portion that extends downward from the body portion and is gripped by an operator, the housing having a dividing surface that divides the housing in the left-right direction;
an accommodating part provided below the handle part, the accommodating part having a protruding part that protrudes forward and leftward from the handle part, and accommodating a board on which an electronic component is mounted;
an input/output operation unit provided to extend in the left-right direction on the upper surface of the protruding portion, and for an operator to perform an input operation;
an opening provided to extend in the left-right direction on the upper surface of the protrusion, the opening having an outer edge that supports the input/output operation section;
A power tool comprising:
a reinforcing portion disposed inside the housing portion at a position directly below a portion where the outer edge of the opening on the handle portion side and the dividing surface intersect, and at a position directly above the substrate ; The power tool is characterized in that the substrate is configured to extend below the reinforcing portion from the front of the reinforcing portion and the portion to the rear of the reinforcing portion and the portion . motor and
A housing including a body portion that accommodates the motor, and a handle portion that extends downward from the body portion and is gripped by an operator, the housing having a dividing surface that divides the housing in the left-right direction;
an accommodating part provided below the handle part, the accommodating part having a protruding part that protrudes forward and leftward from the handle part, and accommodating a board on which an electronic component is mounted;
an input/output operation unit provided to extend in the left-right direction on the upper surface of the protruding portion, and for an operator to perform an input operation;
an opening provided to extend in the left-right direction on the upper surface of the protrusion, the opening having an outer edge that supports the input/output operation section;
A power tool comprising:
The board is housed in the housing part in a state where it is housed inside a dish-shaped board case with an opening at the top,
a reinforcing portion disposed inside the housing portion at a position directly below a portion where the outer edge of the opening on the handle portion side and the dividing surface intersect, and at a position directly above the substrate ; The substrate is configured to extend below the reinforcing part from the front of the reinforcing part and the part to the rear of the reinforcing part and the part ,
The reinforcing portion is configured to extend in the left-right direction from a position to the left of the substrate to a position to the right of the substrate ,
The power tool is characterized in that the reinforcing portion is further configured to extend in the left-right direction from a position to the left of the opening to a position to the right of the opening . motor and
A housing including a body portion that accommodates the motor, and a handle portion that extends downward from the body portion and is gripped by an operator, the housing having a dividing surface that divides the housing in the left-right direction;
an accommodating part provided below the handle part, the accommodating part having a protruding part that protrudes forward and leftward from the handle part, and accommodating a board on which an electronic component is mounted;
an input/output operation unit provided to extend in the left-right direction on the upper surface of the protruding portion, and for an operator to perform an input operation;
an opening provided to extend in the left-right direction on the upper surface of the protrusion, the opening having an outer edge that supports the input/output operation section;
A power tool comprising:
Inside the accommodating portion, a reinforcing portion that extends longer in the left-right direction than the substrate is located at a position directly below the portion where the outer edge of the opening on the handle portion side intersects the dividing surface and directly below the substrate. The power tool is arranged at an upper position, and the base plate is configured to extend below the reinforcing part from the front of the reinforcing part and the part to the rear of the reinforcing part and the part . The reinforcing part is configured as a beam-shaped reinforcing member that spans from the left side of the board to the right side of the board at a position directly below the part and right above the board inside the housing part. The power tool according to any one of claims 1 to 3. When the portion where the outer edge of the opening and the dividing surface intersect is deformed downward due to an impact when the power tool falls, the portion where the outer edge and the dividing surface intersect comes into contact with the reinforcing portion. The power tool according to any one of claims 1 to 4, wherein the portion where the outer edge and the dividing surface intersect does not come into contact with the substrate. The power tool according to any one of claims 1 to 5, wherein the reinforcing portion extends longer in the left-right direction than the opening. The power tool according to any one of claims 1 to 6, wherein the reinforcing portion is made of metal. The power tool according to any one of claims 1 to 7, wherein the reinforcing portion is made of resin.

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