JP2009240023A - Motor controller, brushless motor, and power tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor controller that enables ensuring the performance of heat radiated, produced by a semiconductor power switching element and is advantageous for size reduction, brushless motor, and power tool. <P>SOLUTION: The motor controller includes a drive circuit board 43; FET 411 that is placed on the drive circuit board 43 and generates a current for driving the brushless motor based on power supplied from a power source; a chassis 17; and a heat conducting sheet 71. The chassis 17 is formed of a thermally conductive material and has a plane 711, placed opposite to the upper face 411b of the FET 411; the chassis supports the drive circuit board 43 via a frame 14 and radiates heat produced by the FET 411; and the heat conduction sheet 71 is provided between a plane 171 of the chassis 17 and the upper face 411b of the FET 411 and transfers heat from the FET 411 to the chassis 17. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a motor control device that controls a brushless motor, and a brushless motor and an electric tool using the motor control device.

  There are electric tools such as electric drills and electric drivers that drive tools such as drills and drivers with a motor. A motor control device for controlling a brushless motor provided in a conventional electric tool or the like includes a semiconductor power switching element for generating a current for driving the brushless motor. A semiconductor power switching element turns on and off a large current in a short cycle, and therefore generates a large amount of heat and requires measures for heat dissipation. In addition, in a motor control device provided in an electric tool or the like, it is necessary to arrange the motor control device in a narrow space inside the electric tool or the like. In particular, if there is a gap between the semiconductor power switching element and the heat dissipating member that dissipates heat, heat cannot be efficiently transferred from the semiconductor power switching element to the heat dissipating member, and heat dissipation efficiency is reduced. If the motor control device cannot be reduced in size, the power tool main body becomes larger, and it becomes difficult for the user to grip the power tool or the weight increases, resulting in poor usability.

In addition, as a prior art document regarding the motor control apparatus which controls a motor with a brush, there exists a thing of patent document 1,2.
Japanese Utility Model Publication No. 62-92533 Japanese Patent Laid-Open No. 62-23390

  Therefore, the problem to be solved by the present invention is to provide a motor control device, a brushless motor, and an electric tool that are advantageous for downsizing while ensuring the heat dissipation performance of the heat generated by the semiconductor power switching element.

  In order to solve the above-described problems, according to the first aspect of the present invention, there is provided a motor control device for controlling a brushless motor, which is disposed on an operation unit, a drive circuit board, and the drive circuit board, and is interlocked with the operation unit. At least one semiconductor power switching element that generates a current for driving the brushless motor based on the electric power supplied from the power source by the on / off operation, and a thermally conductive material, A chassis that has an element facing surface disposed so as to face the upper surface opposite to the lower surface on the side of the driving circuit board, supports the driving circuit board, and radiates heat generated by the semiconductor power switching element; The semiconductor is provided between the element facing surface of the chassis and the upper surface of the semiconductor power switching element. At least the rotational speed of the brushless motor is controlled by controlling the semiconductor power switching element based on a heat conductive material that transmits heat of the word switching element to the chassis and an operation given to the operation unit. And a control circuit unit.

  According to a second aspect of the present invention, in the motor control device according to the first aspect of the present invention, there is further provided a positioning member that is interposed between the drive circuit board and the chassis and positions the drive circuit board with respect to the chassis. Prepare.

  According to a third aspect of the invention, in the motor control device according to the first or second aspect of the invention, the at least one semiconductor power switching element is a plurality of chip-type semiconductor power switching elements.

  According to a fourth aspect of the present invention, in the motor control device according to any one of the first to third aspects of the present invention, the control circuit unit includes a control circuit that controls the semiconductor power switching element, and the drive circuit board. And a control circuit board on which the control circuit is disposed.

  According to a fifth aspect of the present invention, in the motor control device according to the fourth aspect of the present invention, the operation unit is configured to respond to a trigger, a trigger holding unit that slidably holds the trigger, and a slide movement of the trigger. A signal generation unit that generates at least a signal for adjusting the rotation speed of the brushless motor and supplies the signal to the control circuit unit, and the chassis supports the drive circuit board and the operation unit. The trigger holding unit, the signal generation unit, and the control circuit board of the control circuit unit are supported.

  According to a sixth aspect of the present invention, in the motor control device according to the fourth or fifth aspect of the present invention, the drive circuit board and the control circuit board are arranged to face each other with a space therebetween.

  According to a seventh aspect of the invention, in the motor control device according to the second aspect of the invention, the positioning member and the trigger holding portion are formed by a continuous member.

  According to an eighth aspect of the present invention, in the motor control device according to any one of the first to seventh aspects of the present invention, the heat conductive material is a heat conductive sheet having elasticity.

  According to a ninth aspect of the present invention, in the motor control device according to any one of the first to seventh aspects, the heat conducting material is a heat conducting grease.

  In the invention of claim 10, in the motor control device according to any one of claims 1 to 9, the heat conducting material is a low molecular siloxane-reducing material in which the proportion of low molecular siloxane contained is reduced. Is formed by.

  Further, in the invention of claim 11, in the motor control device according to any one of claims 1 to 4, the operation unit includes a trigger, a trigger holding unit that holds the trigger so as to be slidable, A signal generation unit that generates at least a signal for adjusting the rotation speed of the brushless motor according to the slide displacement of the trigger and supplies the signal to the control circuit unit, and the signal generation unit includes a slide direction of the trigger And a movable contact that slides on the resistor in response to the slide displacement of the trigger in order to change the voltage of the signal applied to the control circuit.

  Further, in the invention of claim 12, in the motor control device according to any one of claims 1 to 4, the operation unit includes a trigger, a trigger holding unit that holds the trigger slidably, Signal generation for optically or magnetically detecting the slide displacement of the trigger, generating a signal for adjusting at least the rotational speed of the brushless motor in accordance with the slide displacement of the trigger, and supplying the signal to the control circuit unit A part.

  According to a thirteenth aspect of the present invention, in the motor control device according to any one of the second to twelfth aspects of the present invention, the positioning member includes a substrate support portion that supports the drive circuit substrate, and the substrate support The drive circuit board is supported by the part and is screwed to the chassis.

  According to a fourteenth aspect of the present invention, in the motor control device according to any one of the second to twelfth aspects, the positioning member includes a substrate support portion that supports the drive circuit substrate, and the substrate support The drive circuit board is supported by a portion and is clipped to the chassis.

  According to a fifteenth aspect of the present invention, in the motor control device according to any one of the first to fourteenth aspects, the chassis includes a heat radiating fin.

  According to a sixteenth aspect of the present invention, in the motor control device according to any one of the first to fifteenth aspects, the chassis includes the drive circuit board, the at least one semiconductor power switching element, the positioning member, And a plurality of surfaces surrounding the control circuit unit, and the plurality of surfaces are continuously connected.

  According to a seventeenth aspect of the present invention, in the motor control device according to any one of the first to sixteenth aspects of the present invention, the drive circuit board is a multi-layer board in which a plurality of circuit boards are overlapped via an insulating layer. It is constituted by.

  According to an eighteenth aspect of the present invention, in the motor control device according to the fourth aspect of the present invention, the control circuit board is constituted by a multilayer board in which a plurality of circuit boards are stacked with an insulating layer interposed therebetween.

  According to a nineteenth aspect of the present invention, in the motor control device according to any one of the first to eighteenth aspects of the present invention, a vent hole through which internal and external air can flow in at least one of the chassis and the positioning member. Is provided.

  A brushless motor according to a twentieth aspect of the invention includes the motor control device according to any one of the first to twentieth aspects of the invention.

  The electric tool according to the invention of claim 21 includes the brushless motor according to the invention of claim 20.

  According to the first to nineteenth aspects of the present invention, the chassis that supports the drive circuit board on which the semiconductor power switching element is disposed is arranged so that the element facing surface of the chassis faces the upper surface of the semiconductor power switching element. The heat generated by the semiconductor power switching element is dissipated by the chassis. As described above, the chassis serves both as a support member for supporting the drive circuit board and as a heat sink for dissipating the heat generated by the semiconductor power switching element. The motor control device can be reduced in size and simplified while sufficiently ensuring the heat dissipation performance of the heat generated by the semiconductor power switching element.

  In addition, since a heat conductive material for transferring the heat of the semiconductor power switching element to the chassis is provided between the upper surface of the semiconductor power switching element and the element facing surface of the chassis, the upper surface of the semiconductor power switching element and the element facing surface of the chassis It is possible to prevent the heat transfer efficiency between the semiconductor power switching element and the chassis from being lowered due to a gap between the semiconductor power switching element and the chassis.

  According to the second aspect of the present invention, since the drive circuit board is positioned with respect to the chassis by the positioning member interposed between the drive circuit board and the chassis, the positional relationship between the chassis and the drive circuit board is accurately determined. Can be defined. For example, the distance between the upper surface of the semiconductor power switching element and the element facing surface of the chassis can be accurately defined, and the heat dissipation performance of the chassis can be exhibited well.

  In addition, when the drive circuit board is fixed directly to the chassis, the excessive load accompanying the drive is driven so that the element facing surface of the chassis is in close contact with the upper surface of the semiconductor power switching element via a heat conductive material. Although there is a possibility of being applied to the circuit board, in the present invention, by placing a positioning member between the chassis and the drive circuit board, it is possible to prevent an unreasonable load accompanying fixing from being applied to the drive circuit board.

  According to the third aspect of the present invention, since the semiconductor power switching element is a chip-type power switching element, the installation area of the semiconductor power switching element can be reduced, which is advantageous for downsizing of the drive circuit board and the motor control device. is there.

  In addition, since a heat conductive material is provided between the upper surface of the semiconductor power switching element and the element facing surface of the chassis, there is a variation in the gap size between the upper surface of each semiconductor power switching element and the element facing surface of the chassis. However, the variation can be absorbed, and the heat conductive material can be securely adhered to the upper surface of each semiconductor power switching element, and the heat generated by each semiconductor power switching element can be efficiently transmitted to the chassis.

  According to the fourth aspect of the present invention, since the heat-sensitive control circuit is disposed on the control circuit board provided separately from the drive circuit board on which the heat-generating semiconductor power switching element is disposed, the semiconductor power switching is performed. The control circuit can be protected from heat generated by the element, and malfunction of the control circuit due to heat can be avoided.

  According to the invention described in claim 5, since the chassis supports the drive circuit board, and further supports the trigger holding section and the signal generation section of the operation section, and the control circuit board of the control circuit section. Can be simplified and downsized.

  According to the sixth aspect of the present invention, since the drive circuit board of the drive circuit unit and the control circuit board of the control circuit unit are arranged to face each other with a space therebetween, the drive is performed using space effectively. The circuit board and the control circuit board can be arranged, which is advantageous for downsizing the motor control device.

  According to the seventh aspect of the present invention, since the positioning member and the trigger holding portion are formed by a continuous member, the configuration can be further simplified and reduced in size.

  According to the eighth aspect of the invention, since the heat conductive sheet having elasticity is provided between the upper surface of the semiconductor power switching element and the element facing surface of the chassis, the heat conductive sheet is provided on the upper surface of the semiconductor power switching element. The semiconductor power switching element can be reliably brought into close contact, and heat generated by the semiconductor power switching element can be efficiently transmitted to the chassis.

  Moreover, even if a plurality of semiconductor power switching elements are provided, and there is a variation in the gap dimension between the upper surface of each semiconductor power switching element and the element facing surface of the chassis, the variation is absorbed and each semiconductor power switching element is absorbed. A heat conductive material can be reliably adhered to the upper surface of the switching element.

Also, by adjusting the elasticity and thickness of the heat conduction sheet, when the heat conduction sheet is applied between the semiconductor power switching element and the chassis, the heat conduction sheet is not only the upper surface of the semiconductor power switching element. It can be brought into close contact with the side surface portion, whereby the heat generated by the semiconductor power switching element can be more efficiently transmitted to the chassis.
Moreover, since the heat conductive sheet has elasticity, the heat conductive sheet can absorb an impact transmitted from the outside to the motor control device, and can prevent the semiconductor power switching element from being broken or mounted poorly.

  According to the ninth aspect of the present invention, since the heat conduction grease is provided between the upper surface of the semiconductor power switching element and the element facing surface of the chassis, the gap between the upper surface of the semiconductor power switching element and the element facing surface of the chassis. Therefore, the heat conduction grease can be applied without any gap, and the heat generated by the semiconductor power switching element can be efficiently transmitted to the chassis.

  In addition, if a plurality of semiconductor power switching elements are provided, and there is a variation in the gap size between the upper surface of each semiconductor power switching element and the element facing surface of the chassis, the variation is absorbed and the semiconductor power switching is performed. Thermal conductive grease can be applied between the upper surface of the element and the element facing surface of the chassis without any gap.

  In addition, by adjusting the amount of the heat conduction grease to be applied, the heat conduction grease can be given so as to wrap around not only the upper surface of the semiconductor power switching element but also the side face portion, thereby the heat generated by the semiconductor power switching element. It can be transmitted to the chassis more efficiently.

  According to invention of Claim 10, since the heat conductive material is formed of the low molecular siloxane reducing material in which the ratio of the low molecular siloxane contained is reduced, the component of the heat conductive material containing the low molecular siloxane Can be prevented from adhering to the contact of the operation unit and the like to cause a contact failure.

  According to the invention described in claim 11, in order to change the voltage of the signal for motor control given to the control circuit unit by sliding the movable contact on the resistor in accordance with the slide displacement of the trigger, A simple and inexpensive configuration using a so-called slide resistor can generate a motor control signal based on the slide displacement of the trigger.

  According to the invention of claim 12, since the slide displacement of the trigger is detected optically or magnetically and a signal for motor control is generated, the resistor and the movable contact rub against each other like a slide resistor. Therefore, it is possible to prevent the generation of conductive sliding powder that may cause a short circuit or the like in the drive circuit unit or the like.

  According to the thirteenth aspect, since the positioning member is screwed to the chassis, the positioning member and the chassis can be firmly fixed with a simple configuration.

  According to the fourteenth aspect of the present invention, since the positioning member is clipped to the chassis, the positioning member and the chassis can be quickly fixed by clipping without performing complicated operations such as screw tightening. The manufacturing efficiency of the control device is improved.

  According to the invention described in claim 15, the heat dissipation efficiency of the chassis can be improved by providing the heat dissipation fins in the chassis.

  According to the invention described in claim 16, the chassis has a plurality of surfaces surrounding the drive circuit board, at least one semiconductor power switching element, the positioning member, and the control circuit unit, and the plurality of surfaces are continuously provided. Since it has a connected shape, it is possible to reduce the size of the motor control device while sufficiently securing the heat dissipation capacity of the chassis.

  According to the seventeenth aspect of the present invention, the drive circuit board is constituted by a multilayer board in which a plurality of circuit boards are overlapped via an insulating layer, which is advantageous for downsizing of the drive circuit board.

  According to the eighteenth aspect of the present invention, the control circuit board is constituted by a multilayer board in which a plurality of circuit boards are stacked with an insulating layer interposed therebetween, which is advantageous for downsizing of the control circuit board.

  According to the nineteenth aspect of the present invention, at least one of the chassis and the positioning member is provided with the vent through which the inside and outside air can flow, so that the heat generated by the semiconductor switching element can be efficiently radiated.

  According to the twentieth aspect of the invention, it is possible to provide a brushless motor that is advantageous for downsizing while ensuring the heat dissipation performance of the heat generated by the semiconductor power switching element.

  According to the twenty-first aspect of the present invention, it is possible to provide an electric tool that is advantageous for downsizing while ensuring the heat dissipation performance of the heat generated by the semiconductor power switching element.

  FIG. 1 is an external view of an electric tool 1 in which a motor control device 5 according to an embodiment of the present invention is used. Here, the case where the motor control device 5 according to the present embodiment is used in the electric tool 1 is described as an example, but the motor control device 5 according to the present embodiment is not limited to the electric tool 1 and is provided in an arbitrary device. It can be applied to the control of the brushless motor 3.

  In addition, in FIG. 1 and each drawing described later, with the tool mounting portion 2a (described later) of the electric power tool 1 facing the front side as a reference, the front of the electric power tool 1 is the plus Y direction, and the rear is the minus Y direction. The right direction is the plus X direction, the left direction is the minus X direction, the upper direction is the plus Z direction, and the lower direction is the minus Z direction.

  As shown in FIG. 1, the electric tool 1 includes a brushless motor 3 that rotates the output shaft 2, a battery 4 as a power source, and a motor control device 5. A tool attachment portion 2a for attaching a tool such as a drill is provided at the tip of the output shaft 2. The output shaft 2 is provided with a speed reduction mechanism 6 that reduces the rotational speed of the brushless motor 3 and transmits it to the tool mounting portion 2a.

  The brushless motor 3 is driven by a three-phase current of U, V, and W generated by the motor control device 5 based on the electric power from the battery 4. The battery 4 is detachably attached to the lower end of the grip portion 1 a of the electric tool 1 and supplies electric power to the electric tool 1. The motor control device 5 drives and controls the brushless motor 3 based on an operation on a trigger 21 and the like which will be described later. The motor control device 5 according to the present embodiment is miniaturized so as to be disposed in the grip portion 1a. The grip part 1 a is a part that the user holds when using the electric power tool 1. The trigger 21 is a part that is manually operated by the user.

  FIG. 2 is a perspective view of the motor control device 5, FIG. 3 is a left side view when a direction in which the trigger 21 of the motor control device 5 faces forward (plus Y direction), and FIG. 4 shows motor control. 6 is a right side view of the device 5. FIG. 5 is a perspective view when the chassis 17 of the motor control device 5 is removed, FIG. 6 is a right side view of the configuration shown in FIG. 5, and FIG. 7 is a cross-sectional view taken along the line AA in FIG. It is. 8 is a left side view when the covers 15 and 16 are removed from the configuration shown in FIG. 5, and FIG. 9 is a right side view when the covers 15 and 16 are removed from the configuration shown in FIG. FIG. 10 is a block diagram showing an electrical configuration of the motor control device 5. FIG. 11 is a perspective view of the frame 14. FIG. 12 is a perspective view of the trigger 21 and the first and second movable contacts 233 and 243 attached to the trigger 21. FIG. 13 includes a plan view and a side view of the switch circuit board 22. The configurations of the first to third fixed contacts 231, 232, 242 and the resistor 241 provided on the switch circuit board 22, and their contacts 231, It is a figure which shows a mode when the 1st and 2nd movable contact 233,243 slides with respect to 232,242 etc. FIG.

  As shown in FIGS. 2 to 10, the motor control device 5 includes an operation unit 11, a drive circuit unit 12, a control circuit unit 13, a frame 14, covers 15 and 16, and a chassis 17. Of these, the frame 14 corresponds to a positioning member according to the present invention.

  The operation unit 11 includes a trigger 21, a switch circuit board 22, a power switch circuit unit 23, a signal generation unit 24, a rotation direction switch 25, and a rotation direction switch, as shown in FIGS. A protection mechanism 26 and a rotation direction switching operation unit (not shown) are provided.

  As shown in FIG. 12, the trigger 21 includes a pressing portion 21a pressed by the user, and a contact portion 21b extending from the pressing portion 21a in the sliding direction of the trigger 21 and having first and second movable contacts 233 and 234. And. The contact portion 21b of the trigger 21 is accommodated in a trigger holding portion 141 of the frame 14 shown in FIG. 11 together with a biasing mechanism (for example, a spring mechanism) (not shown), and is held so as to be slidable in the sliding direction B. The pressing portion 21a of the trigger 21 is located on the front side of the frame 14 in FIG. The trigger 21 is urged to the front side of the electric power tool 1 by the urging mechanism (in other words, the direction in which the trigger 21 protrudes from the inside of the grip portion 1a), and the pressing portion 21a is the front side of the grip portion 1a. (This is the initial position of the trigger 21.) Then, the trigger 21 is slid from the initial position to the rear side of the electric power tool 1 (in other words, the direction in which the trigger 21 is pushed into the grip portion 1a) against the biasing force. The unit 13 and the drive circuit unit 12 are turned on, and then the rotation of the brushless motor 3 is started. When the operating force for urging the trigger 21 in the direction in which the trigger 21 is pushed into the grip 1a is released, the rotation of the brushless motor 3 is stopped as the trigger 21 is returned to the initial position by the urging mechanism. The power supply to the control circuit unit 13 and the drive circuit unit 12 is turned off. The operation of the motor control device 5 based on the operation of the trigger 21 will be described in detail later.

  The rotation direction switching operation unit is for switching the rotation direction of the brushless motor 3 and is provided on the side surface of the electric tool 1 or the like. In the present embodiment, an operating force for the rotation direction switching operation unit is applied to the rotation direction switching switch 25 via the lever 27, thereby switching a switching contact (not shown) in the rotation direction switching switch 25. The rotation direction switching switch 25 gives a signal (rotation direction switching signal) corresponding to the set rotation direction to the control circuit unit 13. For example, when the rotation direction switching signal is at a high level, the brushless motor 3 is rotated clockwise, and when the rotation direction switching signal is at a low level, the brushless motor 3 is rotated counterclockwise.

  The rotation direction switching protection mechanism 26 is for preventing the rotation direction switching operation unit from being operated during the rotation of the brushless motor 3 and switching the rotation direction of the brushless motor 3. The rotation direction switching protection mechanism 26 includes a convex portion 260 (see FIG. 3 and the like) provided so as to protrude downward on the lower surface side of the tip of the lever 27 and two grooves 261 provided on the upper surface side of the trigger 21. , 262 and a partition wall portion 263 provided between the grooves 261, 262 (refer to FIG. 12 for details). The two grooves 261 and 262 are formed along the slide direction B. The partition wall 263 is provided so as to partition the two grooves 261 and 262. When the trigger 21 is pushed to the rear side of the electric tool 1 from the initial position, the convex portion 260 of the lever 27 enters the groove 261 or the groove 262 from the rear side of the electric tool 1, and the rotation of the lever 27 is the groove. This is blocked by the partition wall 263 between 261 and 262, whereby the rotation direction switching operation unit is locked. As a result, it is possible to prevent the rotation direction of the motor from being switched while the brushless motor 3 is rotating. Note that the groove 261 or 262 into which the convex portion 260 of the lever 27 enters depends on the rotational direction set by the rotational direction switching operation portion. When the trigger 21 is in the initial position, the convex portion 260 of the lever 27 protrudes out of the grooves 261 and 262, so that the lever 27 is allowed to rotate according to the operation of the rotation direction switching operation portion, and the rotation direction Can be switched.

  The power switch circuit unit 23 turns on / off the electric power input to the control circuit unit 13 according to the slide displacement of the trigger 21. The power input to the control circuit unit 13 is generated by a power supply circuit (not shown) based on the power supplied from the battery 4.

  The power switch circuit unit 23 includes first and second fixed contacts 231 and 232 shown in FIG. 13 and a first movable contact 233 shown in FIGS. 12 and 13. The first and second fixed contacts 231 and 232 are formed on the surface of the switch circuit board 22 by a conductive print pattern. The first movable contact 233 is slid in the sliding direction B in accordance with the slide displacement of the trigger 21 to conduct and block between the first fixed contact 231 and the second fixed contact 232.

  More specifically, the first and second fixed contacts 231 and 232 are formed in a substantially band shape along the slide direction B with a space therebetween in a direction perpendicular to the slide direction B. The length of the first fixed contact 231 in the slide direction B is set to be shorter than the length of the second fixed contact 232 in the slide direction, and one of the first and second fixed contacts 231 and 232 in the slide direction B is set. The position of the end portion (for example, the end portion on the rear side of the electric power tool 1 in the direction in which the trigger 21 is pushed by the trigger operation) is aligned with respect to the slide direction B.

  The first movable contact 233 is formed by punching from a metal plate, and includes a first sliding contact portion 233 a that is in sliding contact with the first fixed contact 231 and a second sliding contact that is in sliding contact with the second fixed contact 232. The contact portion 233b is attached to a portion of the contact portion 21b of the trigger 21 facing the switch circuit board 22. The first and second sliding contact portions 233a and 233b have substantially leaf spring-like flexibility, and the first and second fixed contacts 231 and 232 provided on the switch circuit board 22 are connected to the first and second fixed contacts 231 and 232, respectively. The front end portions of the sliding contact portions 233a and 233b are pressed against each other. The first and second slidable contact portions 233a and 233b have a shape in which the tip side is divided into two forks, and further divided into the two forked in contact with the first and second fixed contacts 231 and 232. The part is bent in the shape of a dog leg. As a result, stable contact between the first and second fixed contacts 231 and 232 and the first and second sliding contact portions 233a and 233b is obtained, and the first and second fixed contacts 231 and 232 and the first Smooth sliding contact with the first and second sliding contact portions 23a and 233b is obtained.

  When the trigger 21 is in the initial position, the first and second sliding contact portions 233a and 233b of the first movable contact 233 are at the position P1 shown in FIG. At this time, the first slidable contact portion 233a is located at a position away from the front side of the electric tool 1 of the first fixed contact 231, and the second slidable contact portion 233b is in contact with the second fixed contact 232. The first fixed contact 231 and the second fixed contact 232 are interrupted. As the trigger 21 is pushed to the rear side of the electric tool 1 from the initial position, the first movable contact 233 is slid to the rear side of the electric tool 1 along with the slide displacement of the trigger 21, and the first The second slidable contact portion 233b of the movable contact 233 slides rearward while being in slidable contact with the second fixed contact 232, and the first slidable contact portion 233a contacts the first fixed contact 231. As a result, the first fixed contact 231 and the second fixed contact 232 are electrically connected via the first movable contact 233. Even when the trigger 21 is pushed to the maximum displacement position, the first and second sliding contact portions 233a and 233b of the first movable contact 233 reach the position P2 shown in FIG. 13, but the conduction is maintained. When the operating force with respect to the trigger 21 is released and the trigger 21 returns to the initial position, the first fixed contact 231 and the second fixed contact 231 are moved away from the first fixed contact 231. The connection with the fixed contact is interrupted, and the first and second sliding contact portions 233a and 233b of the first movable contact 233 return to the position P1 shown in FIG.

  The signal generation unit 24 generates a signal for controlling the brushless motor 3 in accordance with the slide displacement of the trigger 21, and supplies the signal to the control circuit unit 13. The signal generator 24 includes a resistor 241 and a third fixed contact 242 shown in FIG. 13, and a second movable contact 243 shown in FIGS.

  The resistor 241 is formed by providing a resistance layer made of a material having a high resistance value (for example, carbon) on the surface of a conductive printed pattern provided on the surface of the switch circuit board 22. The resistor 241 is formed by, for example, applying a resistance material containing carbon on a printed pattern and then solidifying the resistance material by heat treatment or the like.

  The third fixed contact 242 is formed on the surface of the switch circuit board 22 by a conductive printed pattern. The resistor 241 and the third fixed contact 242 are formed in a substantially band shape along the slide direction B with a space therebetween in a direction perpendicular to the slide direction B. For example, a configuration in which a second resistor is provided in parallel with the resistor 241 instead of the third fixed contact 242 can be considered, but in this embodiment, a configuration in which only one resistor 241 is provided is employed. As described above, in the configuration in which only one resistor 241 is provided, compared to the configuration in which two resistors are provided in parallel, the influence of the resistance value error generated in the process of forming the resistance layer of the resistor 241 is reduced. There is an advantage that it can be reduced.

  The second movable contact 243 slides on the resistor 241 and the third fixed contact 242 according to the slide displacement of the trigger 21 in order to change the voltage of the control signal applied to the control circuit unit 13. More specifically, the second movable contact 243 has substantially the same configuration as the first movable contact 233 described above, and includes a first slidable contact portion 243a slidably contacting the resistor 241 and a third fixed contact. And a second slidable contact portion 243 b that is slidably contacted with 242, and is attached to a portion of the contact portion 21 b of the trigger 21 that faces the switch circuit board 22. The first and second sliding contact portions 243a, 243b have substantially leaf spring-like flexibility and the tip side is divided into two forks, as in the case of the first movable contact 233 described above. The bifurcated portion that is in sliding contact with the 241 and the third fixed contact 241 is bent into a dogleg shape.

  When the trigger 21 is in the initial position, the first and second sliding contact portions 243a and 243b of the second movable contact 243 are at a position P3 shown in FIG. At this time, the first and second sliding contact portions 243a and 243b are in contact with the ends of the resistor 241 and the third fixed contact 242 on one end side in the sliding direction B (front side of the electric power tool 1), respectively. Yes. As the trigger 21 is pushed to the rear side of the electric tool 1 from the initial position, the second movable contact 243 is slid to the rear side of the electric tool 1 along with the slide displacement of the trigger 21, and the second The first and second slidable contact portions 243a and 243b of the movable contact 243 slide to the rear side in a state of slidingly contacting the resistor 241 and the third fixed contact 242. Thereby, the position where the first sliding contact portion 243a of the second movable contact 243 contacts the resistor 241 in the sliding direction B is changed, and the resistance value taken out from the resistor 241 can be changed. The principle of the change in signal voltage due to the change in resistance value of the resistor 241 will be described later with reference to the circuit diagram of FIG.

  When the trigger 21 is pushed to the maximum displacement position, the first and second sliding contact portions 243a and 243b of the second movable contact 243 reach a position P4 shown in FIG. When the operating force on the trigger 21 is released, the first and second sliding contact portions 243a and 243b of the second movable contact 243 are moved to the position P3 shown in FIG. 13 as the trigger 21 returns to the initial position. Return.

  FIG. 14 is a diagram illustrating an example of the circuit configuration of the power switch circuit unit 23 and the signal generation unit 24. In the configuration of FIG. 14, reference numerals 31 to 34 are connection portions for electrical connection provided on the switch circuit board 22. The connection part 31 is for taking in electric power from the power supply circuit (not shown), and is electrically connected to the plus terminal of the power supply circuit. The connection unit 32 is for outputting a control signal to the control circuit unit 13 and is electrically connected to a connection unit (not shown) of the control circuit unit 13. The connection portion 33 is for ground connection and is electrically connected to a ground line (not shown). The connection unit 34 is for supplying power from the power supply circuit to the control circuit unit 13 and is electrically connected to a connection unit (not shown) of the control circuit unit 13.

  The first and second fixed contacts 231 and 232 of the power switch circuit unit 23 are inserted in a wiring 35 that connects between the connection units 31 and 34. As described above, the first movable contact 233 conducts and shuts off the first and second fixed contacts 231 and 232 according to the slide displacement of the trigger 21, so that the wiring 35 is turned on and off. As a result, the power supplied to the control circuit unit 13 via the connection unit 34 is turned on and off. Note that the wiring 35 and wirings 36 and 37 to be described later are formed by a conductive print pattern or the like provided on the switch circuit board 22.

  The resistor 241 of the signal generation unit 24 is inserted in a wiring 36 that connects between the connection units 31 and 33. In other words, the connecting portions of the wiring 36 are connected to both ends of the resistor 241 in the longitudinal direction. The third fixed contact 242 is electrically connected to the connection portion 32 via the wiring 37. Therefore, as described above, when the contact position of the first sliding contact portion 243a of the second movable contact 243 with respect to the resistor 241 changes according to the slide displacement of the trigger 21, the resistance value changes at the resistor 241. Then, the voltage of the control signal output to the control circuit unit 13 via the connection unit 32 changes in magnitude. For example, as the amount of slide displacement of the trigger 21 toward the rear side of the electric power tool 1 increases, the resistance value extracted from the resistor 241 increases, and the voltage of the control signal output from the connection portion 32 decreases. It is supposed to be.

  In the present embodiment, the portion of the resistor 241 located at the end on the front side of the electric power tool 1 is a highly conductive section 241a having a low resistance value, and the other portion of the resistor 241 is substantially slid. It is a resistance section 241b that functions as a resistor. The highly conductive section 241a is formed by exposing a conductive print pattern without providing a resistor layer, or by applying a metallic conductive material on the resistor layer. The highly conductive section 241a is not necessarily required, and the entire resistor 241 may be used as the resistor section 241b.

  In the present embodiment, the first and second fixed contacts 231 and 232 and the resistor 241 and the third fixed contact 242 are substantially parallel to the sliding direction B on the surface of the switch circuit board 22. It is provided to shift to. More specifically, the first fixed contact 231 and the resistor 241 are arranged so as to be arranged in a substantially straight line at intervals in the sliding direction B, and the second fixed contact 232 and the third fixed contact 242 are arranged. They are arranged so as to be arranged in a substantially straight line at intervals in the sliding direction B. Thereby, the dimension of the switch circuit board 22 in the direction substantially perpendicular to the sliding direction B can be reduced. As a modification regarding this point, on the surface of the switch circuit board 22, the first and second fixed contacts 231 and 232, the resistor 241 and the third fixed contact 242 are arranged in a direction perpendicular to the sliding direction B. And may be provided in parallel along the slide direction B. This configuration is advantageous for reducing the size of the switch circuit board 22 in the sliding direction B. The arrangement of these contacts may affect the configuration of the motor control device 5, the brushless motor 3, and the electric tool 1. For example, when the motor control device 5 is arranged in the grip portion 1a, the longitudinal dimension of the grip portion 1a can be reduced in the case of the configuration of the present embodiment, while in the case of the configuration of the modification, the grip portion 1a. Can be reduced in diameter.

  The drive circuit unit 12 includes an FET (Field Effect Transistor) circuit 41 and an FET drive circuit 42 shown in FIG. 10, and a drive circuit board 43 shown in FIGS. The FET circuit 41 includes a plurality of semiconductor power switching elements FET411 (see FIG. 5 and the like), and drives the brushless motor 3 based on electric power supplied from the battery 4 by turning on and off the FET411. The three-phase current is generated. In the present embodiment, a chip-type FET 411 in which the body portion of the FET 411 is not covered with a molding material, a casing material, or the like is used as the FET 411 and has a configuration (package type) advantageous for downsizing. As a modification, the FET 411 may be configured such that the main body of the FET 411 is covered with a molding material or a casing material. Further, as another semiconductor power switching element, for example, an IGBT (Insulated Gate Bipolar Transistor) may be employed.

  The FET drive circuit 42 drives the FET circuit 41 based on a control signal given from the control circuit unit 13. The drive circuit board 43 is for mounting circuit components constituting the FET circuit 41 and the FET drive circuit 42.

  The control circuit unit 13 includes a PWM (Pulse Width Modulation) control circuit 131 shown in FIG. 10 and a control circuit board 132 shown in FIG. 7 on which circuit components constituting the PWM control circuit 131 are mounted. . The PWM control circuit 131 includes a microprocessor for PWM control and the like, and controls the rotation of the brushless motor 3 by controlling the drive circuit unit 12 based on a signal given from the operation unit 11.

  As shown in FIG. 10, the brushless motor 3 is provided with a plurality of Hall elements 46 to 48 for detecting a rotational angle position of a rotor (not shown). The PWM control circuit 131 detects the rotational angle position of the rotor of the brushless motor 3 based on a signal given from the Hall elements 46 to 48 via the signal inversion comparator 45, and based on the detection result, The drive circuit unit 12 is caused to generate a three-phase current synchronized with the rotation. In the present embodiment, the comparator 45 is disposed on a substrate provided outside the motor control device 5, but the comparator 45 may be disposed on the control circuit substrate 132.

  The rotation speed of the brushless motor 3 is controlled by the PWM control circuit 131 as follows. The PWM control circuit 131 causes the FET circuit 41 of the drive circuit unit 12 to periodically chop the three-phase current generated by the FET circuit 41 with a short period, and the three-phase current during each chopping period during which chopping is performed. The rotational speed of the brushless motor 3 is changed by increasing or decreasing the ratio (duty ratio) of the period (on period) that is turned on and supplied to the brushless motor 3. For example, when the ratio of the ON period with respect to each chopping cycle period of the three-phase current is increased, the amount of the three-phase current supplied to the brushless motor 3 is increased, and thereby the rotation speed of the brushless motor 3 is increased. . As the rotational speed of the brushless motor 3 increases, the switching period of the three-phase current is also increased. The chopping cycle for chopping the three-phase current is set sufficiently shorter than the rotation cycle of the brushless motor 3 (three-phase current switching cycle).

  FIG. 15 is a diagram illustrating a relationship between the trigger position when the trigger 21 is slid and the resistance value of the resistor 241, the power source, the brake, and the rotation speed of the brushless motor 3. As shown in FIG. 15B, the first and second intermediate positions between the initial position Pa of the trigger 21 and the maximum displacement position Pb when the trigger 21 is pushed most into the rear side of the power tool 1. Pc and Pd are provided. The first intermediate position Pc is provided at a position closer to the initial position Pa than the second intermediate position Pd. The displacement section between the initial position Pa and the first intermediate position Pc is called a stop section Q1, the displacement section between the first intermediate position Pc and the second intermediate position Pd is called a braking section Q2, 2 A displacement section between the intermediate position Pd and the maximum displacement position Pb is referred to as a rotation speed adjustment section Q3.

  As shown in FIG. 15 (c), when the trigger 21 is in the stop section Q1, the first and second fixed contacts 231 and 232 of the power switch circuit unit 23 are disconnected, and the power switch circuit unit The power of the control circuit unit 13 is turned off by 23, and the operation of the drive circuit unit 12 is also stopped. For this reason, when the trigger 21 is in the stop section Q1, the brushless motor 3 does not rotate.

  When the trigger 21 is pushed behind the electric tool 1 beyond the first intermediate position Pc and is positioned in the braking section Q2 or the rotation speed adjustment section Q3, the first and second power switch circuit portions 23 The two fixed contacts 231 and 232 are electrically connected by the first movable contact 233, and the power supply of the control circuit unit 13 is turned on by the power switch circuit unit 23. For this reason, when the trigger 21 is in the braking section Q2 or the rotation speed adjustment section Q3, the control circuit section 13 is connected via the drive circuit section 12 based on the voltage level of the control signal given from the signal generation section 24. The brushless motor 3 is controlled.

  The resistance value extracted from the resistor 241 of the signal generator 24 changes as shown in FIG. 15A according to the slide displacement of the trigger 21. That is, when the trigger 21 is in the stop section Q <b> 1, the first sliding contact portion 243 a of the second movable contact 243 of the signal generation unit 24 is in the high conductive section 241 a of the resistor 241 and is taken out from the resistor 241. The resistance value to be changed does not change, and the voltage level of the control signal does not change.

  When the trigger 21 is pushed behind the electric tool 1 beyond the first intermediate position Pc and is positioned in the braking section Q2 or the rotation speed adjustment section Q3, the first sliding of the second movable contact 243 is performed. The contact portion 243 a is in the resistance section 241 b of the resistor 241. For this reason, the resistance value taken out from the resistor 241 changes according to the slide displacement of the trigger 21, thereby changing the voltage level of the control signal.

  When the trigger 21 is in the braking section Q2, the control circuit unit 13 applies a braking force to the rotation of the brushless motor 3 through the drive circuit unit 12 as shown in FIG. For this reason, in the process in which the operating force is released from the state where the trigger 21 is pushed down to the rotation speed adjustment section Q3 and returns to the initial position Pa, the rotation of the brushless motor 3 is braked when the trigger 21 passes through the braking section Q2. Being stopped quickly. As a result, when the trigger 21 is returned from the rotation speed adjustment section Q3 to the initial position Pa, the rotation of the brushless motor 3 can be stopped quickly, which is advantageous in terms of improving safety. In addition, the braking force with respect to rotation of the brushless motor 3 is given by making the U, V, and W terminals of the brushless motor 3 short by the drive circuit unit 12, for example.

  When the trigger 21 is in the rotation speed adjustment section Q3, as shown in FIG. 15 (e), the control circuit unit 13 receives the control signal supplied from the signal generation unit 24 via the drive circuit unit 12. The brushless motor 3 is rotated at a rotation speed corresponding to the voltage value.

  More specifically, for example, the control circuit unit 13 determines whether or not the voltage value of the control signal supplied from the signal generation unit 24 exceeds a reference value set in advance corresponding to the second intermediate position Pd. By determining whether or not the braking control for the brushless motor 3 is performed, the rotational speed control corresponding to the trigger position is switched.

  The rotation direction of the brushless motor 3 is switched by the control circuit unit 13 based on the signal given from the rotation direction switch 25 described above. The control circuit unit 13 causes the drive circuit unit 12 to generate a three-phase current corresponding to the rotation direction specified by the signal given from the rotation direction switch 25.

  Since the drive circuit unit 12 is interposed between the brushless motor 3 and the battery 4 as described above, the battery 4 and the brushless motor are associated with the power-off of the control circuit unit 13 by the power switch circuit unit 23 of the operation unit 11. 3 can be cut off by the drive circuit unit 12. The power supply current supplied to the control circuit unit 13 is much weaker than the current supplied to the brushless motor 3. Therefore, even if the first and second fixed contacts 231 and 232 of the power switch circuit unit 23 of the operation unit 11 are formed by the conductive print pattern provided on the surface of the switch circuit board 22, the first and second Sufficient resistance to the current and voltage of the second fixed contacts 231 and 232 and the like can be obtained. As a result, the configuration of the first and second fixed contacts 231 and 232, the first movable contact 233 and the like provided in the power switch circuit unit 23 of the operation unit 11 can be reduced in size and cost, and the contacts 231 can be reduced. The durability of ˜233 can also be improved.

  In addition, the first and second fixed contacts 231 and 232 provided in the power switch circuit unit 23 of the operation unit 11 are electrically connected and disconnected by the first movable contact 233 that slides and displaces according to the slide displacement of the trigger 21. Therefore, the displacement width in the sliding direction B of the trigger 21 required for conducting and blocking between the first and second fixed contacts 231 and 232 by the first movable contact 233 can be reduced.

  Further, the voltage of the signal for motor control given to the control circuit unit 13 is changed by sliding the second movable contact 243 on the resistor 241 in accordance with the slide displacement of the trigger 21, so-called slide. A signal for motor control can be generated based on the slide displacement of the trigger 21 with a simple and inexpensive configuration using a resistor.

  Further, the conductive body provided on the surface of the common switch circuit board 22 with the resistor 241 and the third fixed contact 242 of the signal generation unit 24 and the first and second fixed contacts 231 and 232 of the power switch circuit unit 23. Therefore, it is advantageous for downsizing and the number of parts.

  In the present embodiment, the control circuit unit 13 directly receives signals given from the signal generation unit 24 and the rotation direction changeover switch 25 of the operation unit 11 and uses them to control the drive circuit unit 12. For this reason, for example, the configuration can be simplified as compared with a configuration in which an interface control unit including a microprocessor or the like is interposed between the signal generation unit 24 and the rotation direction changeover switch 25 of the operation unit 11 and the control circuit unit 13.

  As shown in FIGS. 7 and 11, the frame 14 includes a trigger holding portion 141, first to third substrate support portions 142 to 144, a partition wall 145, and a substrate holding portion 146. Etc. are formed. The trigger holding part 141 accommodates the trigger 21 and the aforementioned urging mechanism, and holds the trigger 21 so as to be slidable in the sliding direction B. The first board support part 142 supports the switch circuit board 22. The first substrate support portion 142 allows the switch circuit board 22 to have first and second movable contacts attached to the trigger 21 on the surface on which the first to third fixed contacts 231, 232, 242 and the like are provided. It is supported toward the 233,243 side.

  The second substrate support unit 143 supports the drive circuit substrate 43. The second substrate support portion 143 supports the drive circuit substrate 43 with the surface on which the FET 411 is disposed facing the outer surface side (the right outer side (plus X direction) of the electric power tool 1). The third board support portion 144 supports the control circuit board 132. The drive circuit board 43 and the control circuit board 132 are opposed to each other by the second and third board support parts 143 and 144 in the board holding part 146 with an interval in the left-right direction that is a direction perpendicular to the sliding direction B. So that it is supported. As described above, the drive circuit board 43 and the control circuit board 132 are arranged in a two-tiered manner with a space therebetween, so that the drive circuit board 43 and the control circuit board 132 can be effectively used by utilizing the space of the board holding portion 146. The motor control device 5 and the electric tool 1 can be reduced in size.

  Further, since the PWM control circuit 131 that is vulnerable to heat is provided on the control circuit board 132 provided separately from the drive circuit board 43 on which the FET 411 that is a heat generating element is provided, the PWM control circuit 131 is generated from the heat generated by the FET 411. Can be protected, and malfunction of the PWM control circuit 131 due to heat can be avoided.

  Such a drive circuit board 43 and the control circuit board 132 are electrically connected using a plurality of pins 51 as shown in FIG. Thus, the drive circuit board 43 and the control circuit board 132 can be electrically connected with an inexpensive configuration. As a modification regarding this point, the drive circuit board 43 and the control circuit board 132 may be electrically connected via a flexible board. In this case, the drive circuit board 43 and the control circuit board 132 are each provided with a connector to which the flexible board is electrically connected. According to the configuration using the flexible substrate, the installation area of the connection portion (connector or the like) on the drive circuit board 43 and the control circuit board 132 can be reduced as compared with the connection structure using the pins 51, and the drive circuit This is advantageous in reducing the size of the substrate 43, the control circuit substrate 132, and the motor control device 5. When a flexible substrate that can be folded is used as the flexible substrate, the installation space for the flexible substrate can be reduced.

  As shown in FIG. 7, the switch circuit board 22 and the control circuit board 132 are arranged such that the edges of the switch circuit board 22 and the control circuit board 132 partially overlap each other. They are electrically connected to each other using an electrical connection member.

  As shown in FIG. 7 and the like, the partition wall 145 of the frame 14 includes the first to third fixed contacts 231, 232, and 242, the resistor 241, and the first and second movable contacts 233 and 233 of the operation unit 11 described above. An area where the 243 is provided (trigger holding part 141) and an area where the drive circuit part 12 and the control circuit part 13 are arranged (substrate holding part 146) are partitioned. As a result, the following effects can be obtained. That is, the first and second movable contacts 233 and 243 slide on the first to third fixed contacts 231, 232 and 242 and the resistor 241, so that the first and second movable contacts 233 and 243 are moved. The conductive sliding powder may be generated from the surface of the first to third fixed contacts 231, 232, 242 or the resistor 241. However, in the present embodiment, even if such sliding powder is generated, the partition 145 can prevent the sliding powder from entering the region where the drive circuit board 43 and the control circuit board 132 are provided. As a result, it is possible to prevent the sliding powder from adhering to the drive circuit unit 12 or the control circuit unit 13 to cause a short circuit or the like.

  As countermeasures against sliding powder, the following countermeasures can be adopted instead of providing the partition walls 145 or in addition to the countermeasures by the partition walls 145. That is, at least the surface of the resistor 241 and the third fixed contact 242 that is in sliding contact with the second movable contact 243 and the portion of the second movable contact 243 that is in sliding contact with at least the resistor 241 and the third fixed contact 242. A coating for reducing the generation of sliding powder may be applied to at least one of the surfaces. Similarly, at least the first movable contact 233 in the first and second fixed contacts 231, 232 slides at least on the surface, and at least the first and second fixed contacts 231, 232 in the first movable contact 233 slide on. You may provide the coating | cover for reducing generation | occurrence | production of sliding powder to at least any one of the surface of the part which contact | connects. As still another countermeasure, at least the conductive circuit portion exposed to the outside of the drive circuit unit 12 and the control circuit unit 13 may be covered with a coating material having an insulating property.

  The covers 15 and 16 are formed of resin or the like, and are attached to the right side (minus X direction in FIG. 11) and left side (plus X direction in FIG. 11) sides of the frame 14, respectively. The cover 15 covers a portion of the frame 14 where the control circuit board 132 and the switch circuit board 22 are arranged. Further, the cover 16 covers a portion of the frame 14 where the drive circuit board 43 is disposed. However, an opening 16a (see FIG. 5 and the like) is provided in a portion of the cover 16 facing the plurality of FETs 411 mounted on the drive circuit board 43. The FET 411 and a chassis 17 described later are opposed to each other through the opening 16a.

  Various configurations can be adopted as fixing means for the frame 14 and the covers 15 and 16. In this embodiment, as shown in FIGS. 2, 5, and 7, the front and rear portions of the frame 14 are used. By engaging the engagement convex portions 56 to 59 provided on the surface portion with the engagement portions (engagement holes in this embodiment) 61 to 64 of the covers 15 and 16, the covers 15 and 16 are attached to the frame 14. It is fixed. That is, the cover 15 includes a surface that covers the control circuit board 132 and the switch circuit board 22, and two surfaces that are provided with engaging portions at both ends of the surface. Similarly, the cover 16 covers the drive circuit board 43 and includes a surface having an opening 16a and two surfaces provided with engaging portions at both ends of the surface. By using such covers 15 and 16, the trigger 21, the urging mechanism, the control circuit board 132, the switch circuit board 22, and the drive circuit board 43 can be easily fixed to the frame 14.

  The frame 14 and the covers 15 and 16 are not necessarily essential members, and one or both of them may be omitted. When the frame 14 is omitted, the switch circuit board 22, the drive circuit board 43, and the control circuit board 132 are directly supported by the chassis 17 described later.

  As shown in FIG. 2 and the like, the chassis 17 holds the switch circuit board 22 of the operation unit 11, the drive circuit board 43 of the drive circuit unit 12, the control circuit board 132 of the control circuit unit 13, and the like via the frame 14. At the same time, it also serves as a heat sink for radiating the heat generated by the FET 411 of the drive circuit unit 12. More specifically, the chassis 17 is formed of a material having sufficient rigidity and excellent thermal conductivity (for example, aluminum, copper, magnesium, or an alloy thereof, or a high heat dissipation resin). The tool 1 has a substantially U-shaped cross-section when cut along a front-rear direction (slide direction B) and a plane (horizontal plane) parallel to the left-right direction. In other words, the chassis 17 has two surfaces 171 and 172 facing the right and left side portions of the frame 14 and a surface 173 facing the rear surface portion of the frame 14 when fixed to the frame 14. is doing. Various configurations can be adopted as a fixing means for the chassis 17 and the frame 14. In this embodiment, screws 66 and 67 are passed through insertion holes (not shown) provided in the chassis 17 and moved to the frame 14 side. The chassis 17 is fixed to the frame 14 by being screwed into the provided screw holes 68 and 69 (see FIG. 6 and the like) (or screwed into bolts not shown).

  In the present embodiment, the surfaces 171 to 173 of the chassis 17 cover almost the entire right and left side surfaces and the rear surface of the frame 14. Therefore, the chassis 17 includes the switch circuit board 22 of the operation unit 11, the drive circuit board 43 of the drive circuit unit 12, the control circuit board 132 of the control circuit unit 13, the trigger holding unit 141 of the frame 14, and the board holding unit 146. Etc. are covered (or surrounded) from the left and right sides and the rear side.

  As shown in FIG. 16, the surface 171 of the chassis 17 is arranged in parallel with the drive circuit board 43 and faces the FET 411 mounted on the drive circuit board 43 through the opening 16 a of the cover 16. That is, the surface 171 of the chassis 17 faces the upper surface 411b of the FET 411 opposite to the lower surface 411a on the drive circuit board 43 side.

  Between the surface 171 of the chassis 17 and the upper surfaces 411b of the plurality of FETs 411, an elastic heat conductive sheet 71 is sandwiched as a heat conductive material. The heat generated by the FET 411 is transmitted to the chassis 17 by the heat conductive sheet 71. As a result, the heat generated by the FET 411 is efficiently transmitted to the chassis 17 via the heat conductive sheet 71 and radiated.

  Here, the thermal conductive material such as the thermal conductive sheet 71 may contain low-molecular siloxane. The component of the heat conductive material containing low molecular siloxane is a contact portion of the operation portion 11 (first to third fixed contacts 231, 232, 242, resistor 241 and first and second movable contacts 233, 243). Etc.) may cause contact failure.

  Therefore, in the present embodiment, the heat conductive sheet 71 is formed of a material that does not contain low molecular siloxane or a low molecular siloxane-reducing material in which the proportion of low molecular siloxane contained is reduced. As a result, it is possible to avoid the occurrence of contact failure due to the components of the heat conductive sheet 71 containing low-molecular siloxane adhering to the contact portion or the like of the operation unit 11. As a specific standard, for example, it is desirable to form the heat conductive sheet 71 using a material (for example, an acrylic material or a silicone material) having a dimethylpolysiloxane content of 500 ppm or less.

  Thus, the switch circuit board 22 of the operation unit 11, the drive circuit board 43 of the drive circuit unit 12, the control circuit board 132 of the control circuit unit 13, and the like are held by the common chassis 17 via the frame 14, It is excellent in miniaturization and simplification of the configuration.

  Further, since the chassis 17 also serves as a heat sink for radiating the heat generated by the FET 411 of the drive circuit unit 12, the configuration can be further reduced in size and simplified, and the heat generated by the FET 411 is radiated. Therefore, the heat dissipation capacity of the chassis 17 can be effectively ensured.

  Further, as described above, the heat conductive sheet 71 having elasticity is sandwiched between the upper surfaces 411 b of the plurality of FETs 411 and the surface 171 of the chassis 17. For this reason, even if there is a variation in the gap size between the upper surface 411b of each FET 411 and the surface 171 of the chassis 17, the variation is absorbed and the heat conductive sheet is applied to the upper surface 411b of each FET 411 and the surface 171 of the chassis 17. 71 can be reliably adhered, and the heat generated by each FET 411 can be efficiently transmitted to the chassis 17. Further, by adjusting the elasticity and thickness of the heat conductive sheet 71, when the heat conductive sheet 71 is sandwiched between the FET 411 and the chassis 17, the heat conductive sheet 71 is not only the upper surface 411b of each FET 411. It can also be brought into close contact with the side surface portion, whereby the heat generated by each FET 411 can be more efficiently transmitted to the chassis 17. Furthermore, since the heat conductive sheet 71 has elasticity, the heat conductive sheet 71 can absorb an impact transmitted from the outside to the motor control device 5, and can prevent the FET 411 from being broken or defectively mounted.

  Further, since the drive circuit board 43 is positioned with respect to the chassis 17 by the frame 14, the positional relationship between the chassis 17 and the drive circuit board 43 can be accurately defined. For example, the distance between the upper surface 411b of the FET 411 and the surface 171 of the chassis 17 can be accurately defined, and between the upper surface 411b of the FET 411 and the heat conductive sheet 71 or between the heat conductive sheet 71 and the chassis 17. Since there is no gap between each of them, the heat dissipation performance of the chassis 17 can be exhibited well (see FIG. 16).

  Further, the surface 171 of the chassis 17 is in close contact with the upper surface 411b of the FET 411 via the heat conductive sheet 71, whereas the drive circuit board 43 is directly fixed to the chassis 17 without using the heat conductive sheet 71. In such a case, there is a possibility that an unreasonable load accompanying fixing is applied to the drive circuit board 43. However, in the present embodiment, the frame 14 and the chassis 17 are fixed in a state where the drive circuit board 43 is supported by the frame 14, so that an unreasonable load accompanying the fixation is absorbed by the heat conductive sheet 71 and the drive circuit board is absorbed. 43 can be prevented.

  In addition, a portion that supports the drive circuit board 43 and the control circuit board 132 of the frame 14 and a trigger holding portion 141 that holds the trigger 21 so as to be slidable are formed by a single continuous member (frame 14). Therefore, further simplification and downsizing of the configuration can be achieved. As a modification regarding this point, the portion of the frame 14 that supports the drive circuit board 43 and the control circuit board 132 and the trigger holding part 141 may be formed as separate members.

  Further, since the frame 14 and the chassis 17 are fixed by the screws 66 and 67, the frame 14 and the chassis 17 can be firmly fixed with a simple configuration.

  One or both (for example, both) of the drive circuit board 43 and the control circuit board 132 described above are configured by a multilayer board 81 as shown in FIG. In the multilayer substrate 81, circuit patterns 813 and 814 for forming conductive paths are provided on both surfaces of a base substrate 812a made of a glass epoxy material, and other circuit patterns 813 and 814 are provided via an insulating layer 811 thereon. Further, another insulating layer 812 is provided on the other circuit patterns 813 and 814, so that the circuit patterns 813 and 814 have a multilayer structure. By constructing either one or both of the drive circuit board 43 and the control circuit board 132 using such a multilayer board 81, the control circuit board 43 or the control circuit board 132 can be reduced in size, thereby the motor control device. 5 can be miniaturized.

  As such a multilayer substrate 81, a metal may be applied instead of an insulating material such as a glass epoxy material for the base substrate 812a. When the base substrate is made of metal in this way, it itself acts as a heat sink, so that it is possible to suppress the temperature rise of electronic components and the like, and it is easy to reduce the thickness. Even if the same multi-layer board is used for the base board, an insulating material such as a glass epoxy material has an insulating property as compared with the case of metal, so there is no need to insulate the circuit pattern. Manufacturing costs can be reduced, and insulation reliability can be increased.

  Next, a modified example of the configuration according to the above-described embodiment will be described.

  In the above-described embodiment, the signal generation unit 24 of the operation unit 11 is configured using a so-called slide resistor. However, a signal for controlling the rotation speed of the brushless motor 3 according to the slide displacement of the trigger 21 is provided. As long as it can be generated, a signal generator having an arbitrary configuration can be employed. For example, a signal generation unit that detects the slide displacement of the trigger 21 using an optical sensor or a magnetic sensor and generates a signal for controlling the rotation speed of the brushless motor 3 in accordance with the slide displacement of the trigger 21. May be adopted. In the configuration using the optical sensor or the magnetic sensor, the resistor 241 and the movable contact 243 do not rub against each other unlike a slide resistor, so that a short circuit or the like occurs in the drive circuit unit 12 or the control circuit unit 13. It is possible to prevent the occurrence of conductive sliding powder that may be feared.

  Further, in the above-described embodiment, the drive circuit board 43 and the control circuit board 132 are arranged so as to overlap each other with a gap therebetween. However, the present invention is not limited to this, and various arrangement forms can be adopted. For example, the drive circuit board 43 and the control circuit board 132 may be arranged adjacent to each other along substantially the same plane, or the drive circuit board 43 and the control circuit board 132 are driven so as to be perpendicular to the drive circuit board 43. The circuit board 43 and the control circuit board 132 may be disposed.

  In the above-described embodiment, the drive circuit board 43 and the control circuit board 132 are formed by separate boards, but may be formed by a continuous board. This configuration is advantageous in terms of reducing the number of parts and simplifying the assembly process.

  In the above-described embodiment, the switch circuit board 22 and the control circuit board 132 are formed by separate boards, but they may be formed by a continuous board. This configuration is also advantageous in terms of reducing the number of parts and simplifying the assembly process.

  In the above-described embodiment, the heat conductive sheet 71 is used as the heat conductive material interposed between the FET 411 of the drive circuit unit 12 and the chassis 17, but heat conductive grease may be used instead of the heat conductive sheet 71. . Alternatively, as the heat conductive material, a curable heat conductive material that is semi-solid when applied to the FET 411 or the chassis 17 and solidifies after being applied may be used. Even when heat conductive grease or a curable heat conductive material is used, the heat conductive grease or curable heat conductive material can be applied between the upper surface 411b of each FET 411 and the surface 171 of the chassis 17 without a gap. The heat of each FET 411 can be efficiently transferred to the chassis 17. Further, by adjusting the amount of the heat conduction grease or the curable heat conduction material to be applied, the heat conduction grease or the curable heat conduction material can be provided so as to wrap not only the upper surface 411b of the FET 411 but also the side surface portion. As a result, the heat generated by the FET 411 can be more efficiently transferred to the chassis 17.

  Further, for the chassis 17 according to the above-described embodiment, the configurations shown in FIGS. 18 to 21 below may be employed. 18 to 21, the frame 14 and the covers 15 and 16 are omitted for simplification of illustration.

  As shown in FIG. 18, a plurality of heat radiation fins 82 may be provided on the outer surface side of the chassis 17. In the configuration shown in FIG. 18, among the three surfaces 171 to 173 of the chassis 17, the radiation fins 82 are provided on the outer surfaces of the surfaces 171 and 172 that cover the left and right side portions of the frame 14. Thereby, the heat dissipation efficiency of the chassis 17 can be improved. As a modification, the radiating fins 82 may be provided only on the outer surface of the surface 171 facing the FET 411, or the radiating fins 82 may be provided on the outer surfaces of all the surfaces 711.

  Further, as described above, the main body portion of the chassis 17 on which the heat dissipating fins 82 are provided is substantially U even if it is cut along a plane perpendicular to the vertical direction at any position along the vertical direction (Z-axis direction). It has a constant cross-sectional shape with a letter shape. Correspondingly, the radiating fins 82 are also extended in the direction in which the cross-sectional shape of the main body portion of the chassis 17 continues in a constant shape (in the configuration of FIG. 18, the vertical direction (Z-axis direction)). As a result, since the cross-sectional shape of the entire chassis 17 including the heat radiation fins 82 when cut by a plane perpendicular to the vertical direction is constant with respect to the vertical direction, the chassis 17 with the heat radiation fins 82 can be easily formed by extrusion molding or the like. Can be made.

  As another modification example regarding the chassis 17, as shown in FIGS. 19 and 20, the chassis 17 may be configured by combining a plurality of members. In the configuration shown in FIG. 19, the chassis 17 is configured by two members 83 and 84 having a substantially L-shaped cross-section when cut along a plane perpendicular to the vertical direction (Z-axis direction). The portion of the side 83b of the two sides 83a and 83b of the member 83 and the portion of the side 84a of the two sides 84a and 84b of the member 84 are overlapped on the rear surface side of the motor control device 1. In this manner, the chassis 17 is configured by combining the two members 83 and 84. As the material of the members 83 and 84, the same material used for the chassis 17 described above is used.

  In the configuration shown in FIG. 20, the chassis 17 is configured by two members 85 and 86 having a substantially L-shaped cross-sectional shape when cut by a plane perpendicular to the vertical direction (Z-axis direction). And the chassis 17 is comprised by combining the two members 85 and 86 in the cylinder shape where a shape when it cut | disconnects at a surface perpendicular | vertical to an up-down direction becomes a substantially rectangular shape. As the material of the members 85 and 86, the same material used for the above-described chassis 17 is used.

  As yet another modification of the chassis 17, as shown in FIG. 21, the chassis 17 has a substantially rectangular cross-section when cut in a plane perpendicular to the vertical direction (Z-axis direction). A cylindrical shape may be used.

  As described above, various configurations can be employed as the configuration of the chassis 17. For example, in the example shown in FIG. 2 and FIGS. 19 to 21 described above, the chassis 17 has a configuration including three flat surfaces 171 to 173 (or four surfaces), but faces the upper surface 411b of the FET 411. If the inner surface of the surface 171 is flat, the shape of other portions is not limited to flat, and various shapes such as a curved shape can be adopted.

  Further, in the configuration according to the above-described embodiment, the chassis 17 and the frame 14 are fixed by the screws 66 and 67. However, as shown in FIGS. May be fixed. FIG. 23 is a sectional view taken along the line CC in FIG.

  22 and 23, the clip 87 is attached to the chassis 17 so as to sandwich the surfaces 171 and 172 of the chassis 17 from the outside in the left-right direction. As a result, the frame 14 is sandwiched between the surfaces 171 and 172 of the chassis 17, and the chassis 17 and the frame 14 are fixed. In order to prevent the clip 87 from falling off, the engagement portions (for example, engagement holes) on the surfaces 171 and 172 of the chassis 17 are engaged with engagement protrusions 87a and 87b projecting inward from the distal end portion of the clip 87. 171a and 172b are provided. Further, grooves 171 b and 172 b into which the clips 87 are fitted are provided on the outer surfaces of the surfaces 171 and 172 of the chassis 17. As described above, since the chassis 17 and the frame 14 are fixed by the clip 87, the chassis 17 and the frame 14 can be quickly fixed by clip fixing without performing complicated work such as screw tightening. 5 and the manufacturing efficiency of the electric power tool 1 are improved.

  Furthermore, in the configuration shown in FIGS. 22 and 23, the chassis 17 is configured by two members 91 and 92 having a substantially L-shaped cross-sectional shape when cut by a plane perpendicular to the vertical direction (Z-axis direction). Yes. And the two members 91 and 92 are connected by the hinge part 93 so that opening and closing is possible. More specifically, the hinge portion 93 is provided approximately in the middle of the left-right direction (X-axis direction) of the surface 173 of the chassis 17 when viewed from the vertical direction (Z-axis direction). The right half of the surface 173 is formed, and the member 92 forms the portion of the surface 172 of the chassis 17 and the left half of the surface 173. For this reason, the members 91 and 92 are opened and closed by the hinge part 93 in the left-right direction. As the material of the members 91 and 92, the same material used for the chassis 17 described above is used.

  Thus, by providing the hinge part 93 in the chassis 17, since the left and right parts of the chassis 17 can be opened and closed, the chassis 17 can be easily attached to the frame 14. Further, in the configuration in which the chassis 17 is not provided with the hinge portion 93 as in the above-described embodiment, when the chassis 17 has high rigidity, the clamping force of the clip 87 is reduced by the repulsive force of the portions 171 and 172 of the chassis 17. Therefore, there is a possibility that the clamping force exerted on the frame 14 by the chassis 17 for fixing cannot be sufficiently obtained. However, by providing the hinge portion 93 in the chassis 17 as described above, the portions of the surfaces 171 and 172 of the chassis 17 are easily displaced inward in the left-right direction as the clip 87 is attached and pressed against the frame 14. . As a result, the holding force exerted on the frame 14 by the chassis 17 for fixing can be sufficiently obtained without reducing the holding force of the clip 87.

  The configuration shown in FIG. 24 is substantially different from the configuration shown in FIGS. 22 and 23 described above only in terms of the shape of the clip 88 and the engagement structure between the clip 88 and the chassis 17, and the other parts are substantially the same. In common. In the configuration shown in FIG. 24, the clip 88 is mounted so as to be sandwiched from the left and right directions by the portions of the surfaces 171 and 172 of the chassis 17. At this time, the engaging portions 88a and 88b at the distal end portion of the clip 88 are engaged with engaging portions (for example, engaging concave portions) 171c and 172c provided on the outer surface of the surface 171 and 172 of the chassis 17. As a result, the frame 14 is sandwiched between the surfaces 171 and 172 of the chassis 17, and the chassis 17 and the frame 14 are fixed.

  Further, at least one of the chassis 17 and the frame 14 according to the above-described embodiment may be provided with a vent through which air inside and outside the chassis 17 or the frame 14 can flow. By providing the vent hole in this way, the heat generated by the FET 411 can be efficiently radiated.

  Various configurations can be adopted for the position where the vent is provided, the shape of the vent, and the like. For example, a configuration in which the vents 96 and 97 are provided in the hatched portion of FIG. 25 or FIG. In the configuration shown in FIG. 25, a vent 96 is provided in a portion facing the front side of the frame 14 and the covers 15 and 16. In the configuration shown in FIG. 26, a vent 97 is provided in a portion facing the lower surface side of the frame 14.

  In addition, when one or both of the drive circuit board 43 and the control circuit board 132 according to the above-described embodiment can be a circuit board that uses metal and has only one surface as a mounting surface, the various chassis described above The inner surface of 17 can be the mounting surface. In this way, the number of parts of the motor control device can be reduced and the thickness can be reduced.

1 is an external view of an electric tool using a motor control device according to an embodiment of the present invention. It is a perspective view of the motor control apparatus with which the electric tool of FIG. 1 is equipped. FIG. 3 is a left side view when a direction in which the trigger of the motor control device in FIG. 2 faces forward (plus Y direction) is a reference. FIG. 3 is a right side view of the motor control device of FIG. 2. It is a perspective view when the chassis of the motor control device of FIG. 2 is removed. It is a right view of the structure shown in FIG. It is sectional drawing along the AA line of FIG. It is a left view when a cover is removed from the structure shown in FIG. It is a right view when a cover is removed from the structure shown in FIG. It is a block diagram which shows the electric constitution of the motor control apparatus of FIG. It is a perspective view of a frame. It is a perspective view of the 1st and 2nd movable contact attached to the trigger and the trigger. Including the plan view and the side view of the switch circuit board, the first to third fixed contacts and the resistor provided on the switch circuit board, and the first and second movable contacts with respect to these contacts, etc. It is a figure which shows a mode when sliding. It is a figure which shows an example of the circuit structure of a power switch circuit part and a signal generation part. It is a figure which shows the relationship between the trigger position when a trigger is slid, and the rotational speed of a resistance value of a resistor, a power supply, a brake, and a brushless motor. It is sectional drawing of the part by which FET and the chassis of a drive circuit part are arrange | positioned facing. It is sectional drawing which shows the structure of the multilayer substrate used for a drive circuit board or a control circuit board. It is sectional drawing which shows the structural example which provided the radiation fin in the chassis. It is sectional drawing which shows the 1st structural example which comprised the chassis combining two members. It is sectional drawing which shows the 2nd structural example which comprised the chassis combining two members. It is sectional drawing which shows the structural example which made the chassis the substantially cylindrical shape. It is sectional drawing which shows the 1st structural example which fixes a chassis and a frame with a clip. It is sectional drawing along CC line of FIG. It is sectional drawing which shows the 2nd structural example which fixes a chassis and a frame with a clip. It is a figure which shows the 1st structural example which provided the vent hole in the flame | frame and cover when seeing a motor control apparatus from the front side. It is a figure which shows the 2nd structural example which provided the vent hole in the flame | frame when a motor control apparatus is seen from the lower surface side.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Electric tool, 2 Output shaft, 3 Brushless motor, 4 Battery, 5 Motor control apparatus, 6 Reduction mechanism, 11 Operation part, 12 Drive circuit part, 13 Control circuit part, 14 Frame, 15, 16 Cover, 17 Chassis, 21 Trigger, 22 Switch circuit board, 23 Power switch circuit section, 24 Signal generation section, 25 Rotation direction switch, 26 Rotation direction switching protection mechanism, 27 Lever, 41 FET circuit, 42 FET drive circuit, 43 Drive circuit board, 51 pins , 71 Thermal conductive sheet, 81 Multi-layer board, 82 Radiation fin, 87, 88 clip, 96, 97 Vent, 131 PWM control circuit, 132 Control circuit board, 141 Trigger holding part, 142 First board support part, 143 First 2 substrate support part, 144 third substrate support part, 145 partition, 146 Plate holding portion, 171 to 173 surface, 231 first fixed contact, 232 second fixed contact, 233 first movable contact, 233a first sliding contact portion, 233b second sliding contact portion, 241 resistor, 242 first 3 fixed contacts, 243 second movable contact, 243a first sliding contact portion, 243b second sliding contact portion, 244 resistor, 411 FET, 811, 812 insulating layer, 812a base substrate, 813, 814 circuit pattern.

Claims (21)

A motor control device for controlling a brushless motor,
An operation unit;
A drive circuit board;
At least one semiconductor power switching element that is disposed on the drive circuit board and generates a current for driving the brushless motor based on power supplied from a power source by an on / off operation linked to the operation unit;
An element facing surface that is formed of a thermally conductive material and is disposed so as to face the upper surface opposite to the lower surface of the semiconductor power switching element on the drive circuit board side, and supports the drive circuit board A chassis that dissipates heat generated by the semiconductor power switching element;
A heat conductive material provided between the element facing surface of the chassis and the upper surface of the semiconductor power switching element, and transferring heat of the semiconductor power switching element to the chassis;
A control circuit unit that controls at least the rotational speed of the brushless motor by controlling the semiconductor power switching element based on an operation given to the operation unit;
A motor control device comprising: The motor control device according to claim 1,
The motor control device further comprising a positioning member interposed between the drive circuit board and the chassis and positioning the drive circuit board with respect to the chassis. In the motor control device according to claim 1 or 2,
The motor control device, wherein the at least one semiconductor power switching element is a plurality of chip-type semiconductor power switching elements. In the motor control device according to any one of claims 1 to 3,
The control circuit unit is
A control circuit for controlling the semiconductor power switching element;
A control circuit board configured separately from the drive circuit board and provided with the control circuit;
A motor control device comprising: The motor control device according to claim 4,
The operation unit is
Triggers,
A trigger holding section that holds the trigger in a slidable manner;
A signal generation unit that generates a signal for adjusting at least the rotation speed of the brushless motor according to the slide movement of the trigger and supplies the signal to the control circuit unit;
With
The chassis supports the drive circuit board, and also supports the trigger holding section and the signal generation section of the operation section, and the control circuit board of the control circuit section. . In the motor control device according to claim 4 or 5,
The motor control device, wherein the drive circuit board and the control circuit board are arranged to face each other with a space therebetween. The motor control device according to claim 2,
The motor control device, wherein the positioning member and the trigger holding portion are formed by a continuous member. The motor control device according to any one of claims 1 to 7,
The motor control device, wherein the heat conductive material is a heat conductive sheet having elasticity. The motor control device according to any one of claims 1 to 7,
The motor control device, wherein the heat conductive material is heat conductive grease. The motor control device according to any one of claims 1 to 9,
The motor control device, wherein the heat conducting material is formed of a low molecular siloxane-reducing material in which the proportion of low molecular siloxane contained is reduced. In the motor control device according to any one of claims 1 to 4,
The operation unit is
Triggers,
A trigger holding portion for holding the trigger in a slidable manner;
A signal generation unit that generates a signal for adjusting at least the rotational speed of the brushless motor according to the slide displacement of the trigger and supplies the signal to the control circuit unit;
With
The signal generator is
A resistor formed along the sliding direction of the trigger;
A movable contact that slides on the resistor in response to the slide displacement of the trigger to change the voltage of the signal applied to the control circuit;
A motor control device comprising: In the motor control device according to any one of claims 1 to 4,
The operation unit is
Triggers,
A trigger holding section that holds the trigger in a slidable manner;
Signal generation for optically or magnetically detecting the slide displacement of the trigger, generating a signal for adjusting at least the rotational speed of the brushless motor in accordance with the slide displacement of the trigger, and supplying the signal to the control circuit unit And
A motor control device comprising: The motor control device according to any one of claims 2 to 12,
The motor control apparatus according to claim 1, wherein the positioning member includes a substrate support portion that supports the drive circuit substrate, and is screwed to the chassis in a state where the drive circuit substrate is supported by the substrate support portion. The motor control device according to any one of claims 2 to 12,
The motor control device according to claim 1, wherein the positioning member has a substrate support portion that supports the drive circuit board, and is clipped to the chassis in a state where the drive circuit substrate is supported by the substrate support portion. The motor control device according to any one of claims 1 to 14,
The motor control apparatus according to claim 1, wherein the chassis is provided with heat radiating fins. The motor control device according to any one of claims 1 to 15,
The chassis has a plurality of surfaces surrounding the drive circuit board, the at least one semiconductor power switching element, the positioning member, and the control circuit unit, and the plurality of surfaces are continuously connected. A motor control device. The motor control device according to any one of claims 1 to 16,
The motor control device, wherein the drive circuit board is constituted by a multilayer board in which a plurality of circuit boards are stacked with an insulating layer interposed therebetween. The motor control device according to claim 4,
The motor control device, wherein the control circuit board is constituted by a multilayer board in which a plurality of circuit boards are stacked with an insulating layer interposed therebetween. The motor control device according to any one of claims 1 to 18,
A motor control device according to claim 1, wherein at least one of the chassis and the positioning member is provided with a vent hole through which internal and external air can flow.   A brushless motor comprising the motor control device according to any one of claims 1 to 19.   An electric tool comprising the brushless motor according to claim 20.

Images