JP2018015867A - Electric work machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively utilize a circuit board space in an electric work machine while ensuring radiation performance of electronic components.SOLUTION: An electric work machine including a motor as a power source comprises: a circuit board 16 which constitutes a controller 15 controlling a motor; and a metal case 33 which accommodates the circuit board 16. The case 33 includes side wall parts 33a-33d surrounding side edges 16a-16d of the circuit board 16. A height and thickness of a portion 41 facing a diode bridge 21 and a switching element 22 implemented on the circuit board 16 among the side wall parts 33a-33d is larger than that of the other portions. The portion 41 is connected to the diode bridge 21 and the switching element 22 so as to be capable of conducting heat.SELECTED DRAWING: Figure 3

Description

  The present disclosure relates to an electric working machine.

  Patent Document 1 describes that in an electric tool, a switching element and a rectifying element fixed to a circuit board are connected to an aluminum heat dissipating member present on the circuit board.

JP 2012-20363 A

  Since the technique of Patent Document 1 is intended to ensure heat dissipation performance only with a heat dissipation member dedicated to heat dissipation connected to an electronic component so as to conduct heat, a large heat dissipation member is required. For this reason, in the circuit board, a space for mounting components or forming wirings, that is, a space for forming an electronic circuit is reduced. That is, the space on the circuit board cannot be used effectively.

  Therefore, one aspect of the present disclosure provides a technique that enables a circuit board space to be effectively used in an electric working machine while ensuring heat dissipation performance of electronic components.

  An electric working machine according to one aspect of the present disclosure includes a motor as a power source of the electric working machine, a circuit board that constitutes a controller that controls the motor, and a metal case that houses the circuit board. The case includes a bottom portion facing the back surface, which is one surface of the circuit board, and a side wall portion surrounding the side edge of the circuit board. And one or more specific electronic components electrically connected to the circuit board and the specific part in the side wall part of a case are connected so that heat conduction is possible.

  In such an electric work machine, heat generated in a specific electronic component is transmitted to a specific portion in the side wall portion of the case, and then transmitted to the entire case or released from the case to the atmosphere or the like. Since the heat capacity and area of the case are large, it is possible to ensure heat dissipation of specific electronic components. And about the heat dissipation of a specific electronic component, it is not necessary to provide a metal heat radiating member on a circuit board. For example, even if a heat radiating member is provided, the heat radiating member can be reduced in size by connecting a specific electronic component and a specific portion of the case through the heat radiating member so as to allow heat conduction. Therefore, the space of the circuit board can be effectively used while ensuring the heat dissipation performance of the electronic component.

  Of the side wall portion of the case, the specific portion may be higher in height from the bottom than other portions. According to the electric working machine configured as described above, since the heat capacity and area of the specific part can be increased, the heat dissipation effect of the electronic component can be improved.

  Of the side wall of the case, the specific portion may be thicker than other portions. According to the electric working machine configured as described above, the heat capacity of the specific part can be increased, so that the heat dissipation effect of the electronic component can be improved.

  The specific electronic component may be fixed in a state where the specific electronic component is erected on the end of the circuit board. In this case, the surface of the specific electronic component on the specific portion side (hereinafter referred to as the back surface) and the specific portion of the case may be connected so as to be able to conduct heat. Further, in this case, a guide portion that contacts the side edge of the circuit board may be provided on the side wall portion of the case that faces the specific portion. And this guide part may be a guide part from which the protrusion amount to the said specific part side becomes large as it goes to the bottom part side from the upper side which is the opposite side to the bottom part side.

  According to the electric working machine configured as described above, the distance between the back surface of the specific electronic component and the specific portion is gradually reduced by performing the following storage operation as the operation of storing the circuit board in the case. However, the circuit board can be accommodated in the case. The accommodating operation is to accommodate the circuit board in the case while the side edge of the circuit board is in contact with the guide part on the side edge opposite to the end part side on which the specific electronic component is fixed. That is the work.

  For example, heat radiation grease may be applied to the back surface of a specific electronic component before the circuit board is accommodated in the case. The heat dissipation grease is grease for facilitating heat transfer from a specific electronic component to a specific portion of the case. In this case, when the circuit board is accommodated in the case while the back surface of the specific electronic component and the specific portion of the case are almost in contact with each other, the heat dissipation grease applied to the specific electronic component is located above the specific portion of the case. There is a disadvantage that it is almost scraped off by the vicinity of the end. Further, even if the heat radiation grease is applied not on the specific electronic component but on the surface in contact with the specific electronic component in the specific portion of the case, the same problem occurs. In other words, when the circuit board is housed in the case while the back of the specific electronic component and the specific part of the case are almost in contact, the heat dissipation grease applied to the specific part of the case is below the specific electronic component. It is almost scraped off by the vicinity of the edge. In this case, the lower side is the bottom side of the case. On the other hand, if the circuit board can be accommodated in the case while the distance between the back surface of the specific electronic component and the specific part of the case is gradually reduced by the above-described housing operation, the heat radiation grease is scraped off. Can be suppressed.

  The guide portion may be a protrusion having a longitudinal direction from the upper side to the bottom side. In this case, the portion of the circuit board that contacts the guide portion may be a portion that is cut out in a state in which the circuit board is viewed in plan. According to the electric working machine configured as described above, the guide portion enters a notched portion of the circuit board. Therefore, the area of the circuit board can be increased.

  Of the plurality of electronic components electrically connected to the circuit board, another electronic component that is different from the specific electronic component and the bottom of the case may be connected so as to be capable of conducting heat. . In such an electric working machine, the heat generated in the separate electronic component is transmitted to the bottom of the case, and then transmitted to the entire case or released from the case to the atmosphere or the like. Therefore, it is not necessary to provide a metal heat dissipating member on the circuit board also for heat dissipation of another electronic component. For this reason, it becomes possible to use the space of the circuit board more effectively.

  At the bottom of the case, a thermal connection portion that is a portion that is connected to another electronic component so as to be able to conduct heat may be recessed on the side opposite to the circuit board side. According to the electric working machine configured as described above, it is possible to reduce the distance between the circuit board and the portion of the bottom that is not the heat connection portion. As a result, the height of the side wall portion of the case can be reduced.

  In the bottom of the case, a heat radiating fin may be provided on the surface opposite to the heat connecting portion. According to the electric working machine configured as described above, the heat dissipation effect of another electronic component can be improved. Moreover, the radiation fin is not limited to the bottom, and may be provided on at least one surface of the case. This is because the heat radiation effect from the case can be improved by the heat radiation fins.

It is a perspective view showing the external appearance of an electric working machine. It is a schematic circuit diagram showing the electric constitution of a controller. It is a perspective view showing the controller of the state in which the circuit board was accommodated in the case. It is a perspective view which represents a circuit board and a case separately. It is a front view of a controller. It is a rear view of a controller. It is a right view of a controller. It is a top view of a controller. It is a bottom view of a controller. It is a front view of a circuit board. It is a right view of a circuit board. It is a top view of a circuit board. It is a bottom view of a circuit board. It is a front view of a case. It is a top view of a case. It is XVI-XVI sectional drawing in FIG. It is sectional drawing similar to FIG. 16 for demonstrating the accommodation operation | work which accommodates a circuit board in a case, and the effect | action of a guide part. It is explanatory drawing explaining another matter. It is the 1st explanatory view explaining other embodiments. It is the 2nd explanatory view explaining other embodiments. It is the 3rd explanatory view explaining other embodiments. It is the 4th explanatory view explaining other embodiments.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.
[1-1. Overall configuration of electric work machine]
As shown in FIG. 1, the electric working machine 1 according to the present embodiment is configured as a saw that is used mainly for cutting a workpiece, and includes a base 2 and a main body 3. The base 2 is a substantially rectangular member that comes into contact with the upper surface of the workpiece to be cut when the workpiece is cut. The main body 3 is disposed on the upper surface side of the base 2.

  The main body 3 includes a circular saw blade 4, a saw blade case 5, a cover 6, a main body casing 7, and a handle 10. The saw blade 4 is arranged on the right side of the cutting direction in the main body 3. The saw blade case 5 is provided so as to accommodate and cover the periphery of the upper half of the saw blade 4 in the range of approximately a half circumference. The cover 6 is provided so as to cover the periphery of the lower half of the saw blade 4 in a substantially half-circumferential range.

  The cover 6 is of an openable type, and FIG. 1 shows a state where the cover 6 is closed. The cover 6 is gradually opened in a counterclockwise direction in the drawing around the rotation center of the saw blade 4 by moving the electric working machine 1 in the cutting progress direction when cutting the workpiece. . Thereby, the saw blade 4 is exposed, and the exposed portion is cut into the workpiece.

  The main casing 7 is arranged on the left side of the main body 3 in the cutting progress direction. The main body casing 7 includes a substantially cylindrical motor housing portion 8 and a substantially rectangular parallelepiped controller housing portion 9.

  A motor 19 as a power source of the electric working machine 1 is accommodated in the motor accommodating portion 8. A controller 15 that controls driving of the motor 19 is accommodated in the controller accommodating portion 9. The motor 19 and the controller 15 are not shown in FIG. 1 and are shown in FIG. The motor housing 8 also houses a fan that is rotated by the motor 19. The fan is connected to the rotating shaft of the motor 19 directly or via a speed reduction mechanism or the like, and rotates when the motor 19 rotates to generate cooling air. A gear mechanism for decelerating the rotation of the motor 19 and transmitting it to the saw blade 4 is housed between the motor housing portion 8 and the saw blade 4 in the main body 3.

  In the main casing 7, a first vent 7 a is formed on the left side surface of the motor housing 8 in the cutting progress direction, and a second vent 7 b is formed on the rear end surface of the controller housing 9 in the cutting progress direction. The internal space of the main casing 7 and the outside communicate with each other through these vents 7a and 7b. When the fan is rotated by the rotation of the motor 19, wind from the fan is generated inside the main body casing 7. The main flow path of the wind is a flow path in which air that has flowed into the main body casing 7 from the first vent 7a flows out of the second vent 7b through the main casing 7. In the main casing 7, the motor 19 and the controller 15 are arranged on a wind flow path by a fan.

  A handle 10 for the user of the electric working machine 1 to grip the main body 3 is provided in an arch shape. That is, one end of the handle 10 is fixed to the rear end side in the cutting progress direction of the main body 3, and the other end is fixed to the front in the cutting progress direction from the rear end. In the present embodiment, the main body 3 and the handle 10 are integrally formed of, for example, a resin material.

  A trigger-type operation switch 11 is provided on the surface of the handle 10 facing the main casing 7. The operation switch 11 is a switch that conducts (that is, turns on) an electrical contact when pulled. The user of the electric work machine 1 can operate the operation switch 11 while holding the handle 10.

A power cord 12 is drawn from the rear end of the main body 3 in the cutting progress direction. A power plug (not shown) is provided at the tip of the power cord 12.
The power cord 12 is for taking in driving power for the motor 19. By inserting the power plug at the tip of the power cord 12 into the outlet of the AC power source 13, power can be taken from the AC power source 13 through the power cord 12. The AC power supply 13 is not shown in FIG. 1 and is shown in FIG. The AC power supply 13 is a commercial power supply, for example.

  The controller 15 operates when power is supplied from the AC power supply 13 via the power cord 12. Then, the controller 15 rotates the motor 19 when the operation switch 11 is in an operation state (that is, an on state). When the motor 19 rotates, the saw blade 4 rotates.

[1-2. Controller electrical configuration]
As shown in FIG. 2, the controller 15 includes a circuit board 16 that forms an electronic circuit. A plurality of electronic components are mounted on the circuit board 16.

  Examples of the electronic components mounted on the circuit board 16 include a microcomputer (hereinafter referred to as a microcomputer) 20 as a control unit, a diode bridge 21, a switching element 22, an IPM 23, a capacitor 24, a resistor 26, and the like. IPM stands for intelligent power module. Further, examples of the electronic components mounted on the circuit board 16 include an electronic component constituting the current detection circuit 27 and an electronic component constituting the power supply circuit 28.

  The diode bridge 21 full-wave rectifies the AC voltage input from the AC power supply 13 via the power cord 12 and the fuse 14, and uses the voltage after the full-wave rectification between the power supply line Lp and the ground line Lg in the circuit board 16. Output in between. The output voltage of the diode bridge 21 appears as the voltage of the power supply line Lp with respect to the ground line Lg.

  A capacitor 18 that smoothes the output voltage of the diode bridge 21 is provided between the power supply line Lp and the ground line Lg. The DC voltage smoothed by the capacitor 18 becomes a DC voltage for driving the motor 19 (hereinafter referred to as motor drive voltage). That is, the diode bridge 21 and the capacitor 18 constitute a power supply unit that generates a DC motor drive voltage from an AC voltage. Since the capacitor 18 is relatively large, it is provided outside the circuit board 16. The capacitor 18 may be mounted on the circuit board 16.

  Between the power line Lp and the power terminal 31a of the IPM 23, the operation switch 11 and the switching element 22 are provided in series. A resistor 26 is connected as a current detection resistor between the ground line Lg and the ground terminal 31 b of the IPM 23. For this reason, when the operation switch 11 and the switching element 22 are turned on, the motor drive voltage is supplied to the IPM 23. The switching element 22 is, for example, an FET, but may be another type of switching element such as an IGBT or a bipolar transistor. FET is an abbreviation for a field effect transistor, and IGBT is an abbreviation for an insulated gate bipolar transistor.

  The IPM 23 includes switching elements Q1 to Q3 as three high-side switches and switching elements Q4 to Q6 as three low-side switches. The switching elements Q1 to Q3 are switching elements for connecting the terminals of each phase of the motor 19 to the power supply terminal 31a of the IPM 23, respectively. The switching elements Q4 to Q6 are switching elements for connecting each phase terminal of the motor 19 to the ground terminal 31b of the IPM 23, respectively. That is, these six switching elements Q <b> 1 to Q <b> 6 constitute an inverter circuit for driving the motor 19. The switching elements Q1 to Q6 are, for example, IGBTs, but may be other types of switching elements such as FETs and bipolar transistors.

  The IPM 23 also includes a drive signal generation circuit 29 and a protection circuit 30. The drive signal generation circuit 29 outputs the drive signal to the gates of the switching elements Q1 to Q6 according to the control signal from the microcomputer 20, thereby turning on / off the switching elements Q1 to Q6. An energization path to the motor 19 is formed when any of the switching elements Q1 to Q6 is turned on. The protection circuit 30 outputs an abnormality detection signal to the microcomputer 20 when detecting an abnormality such as, for example, that the temperature of the switching elements Q1 to Q6 is equal to or higher than the overheat determination value.

  The capacitor 24 is connected between the power supply terminal 31a of the IPM 23 and the ground line Lg. Capacitor 24 functions as a snubber circuit for suppressing spike-like high voltage generated when switching elements Q1 to Q6 are switched. Note that another capacitor may be connected in parallel to the capacitor 24. In that case, a capacitor in parallel with the capacitor 24 also functions as a snubber circuit.

  At both ends of the resistor 26, a voltage corresponding to a current (hereinafter referred to as motor current) flowing through the motor 19 via the IPM 23 is generated. The current detection circuit 27 outputs a voltage signal obtained by amplifying the voltage generated at both ends of the resistor 26 to the microcomputer 20 and the IPM 23 as a current detection signal representing the motor current.

  The microcomputer 20 is a well-known one configured mainly with a CPU, a ROM, a RAM, and the like, and performs various processes for controlling the motor 19 according to a program stored in the ROM.

  When the microcomputer 20 detects that the operation switch 11 is turned on, the microcomputer 20 turns on the switching element 22 and further outputs a control signal to the IPM 23 to turn on and off the switching elements Q1 to Q6, thereby operating the motor 19.

  When the abnormality detection signal is output from the IPM 23 or when the microcomputer 20 determines that the motor current has become equal to or greater than the overcurrent determination threshold based on the current detection signal from the current detection circuit 27. Fail-safe processing for forcibly stopping the motor 19 is performed. For example, the microcomputer 20 performs a process of stopping the output of the control signal to the IPM 23 and turning off the switching element 22 as the fail-safe process. When the switching element 22 is turned off, the supply of the motor drive voltage to the IPM 23 is stopped.

  On the other hand, the protection circuit 30 in the IPM 23 detects that the motor current has become excessive (hereinafter referred to as overcurrent) as one of the abnormalities based on the current detection signal from the current detection circuit 27. When an overcurrent is detected by the protection circuit 30, the drive signal generation circuit 29 turns off the switching elements Q1 to Q6.

  The power supply circuit 28 generates a constant power supply voltage by stepping down the motor drive voltage generated between the power supply line Lp and the ground line Lg. The microcomputer 20 operates by receiving the power supply voltage generated by the power supply circuit 28.

  Therefore, in the electric work machine 1, when the power plug is inserted into the outlet of the AC power supply 13 and supplied with power from the AC power supply 13 through the power cord 12, a power supply voltage is generated by the power supply circuit 28. The microcomputer 20 is activated. Then, the microcomputer 20 operates the motor 19 in response to the operation switch 11 being turned on.

[1-3. Controller mechanical configuration]
Next, the mechanical configuration of the controller 15 will be described with reference to FIGS. In the following description, the up / down, left / right, and front / rear directions are directions indicated by arrows in FIG. 3, 4, 8, and 10 to 13, only three of the electronic components mounted on the circuit board 16, the diode bridge 21, the switching element 22, and the IPM 23 are illustrated. Yes.

  As shown in FIGS. 3 and 4, the controller 15 includes a circuit board 16 that forms the electronic circuit shown in FIG. 2, and a metal case 33 that houses the circuit board 16. The case 33 is formed of aluminum, but may be formed of other types of metals such as iron and copper.

  As shown in FIGS. 3, 4, 8, and 10 to 13, the circuit board 16 is formed in a substantially rectangular shape having four side edges 16a to 16d. Of the side edges 16a to 16d of the circuit board 16, the side edges 16a and 16c are side edges corresponding to the long sides of the rectangle, and the side edges 16b and 16d are side edges corresponding to the short sides of the rectangle.

  On the upper surface (hereinafter referred to as the front surface) of the circuit board 16 in FIG. 3, the diode bridge 21 and the switching element 22 are laid side by side at, for example, a corner near the side edge 16 b of the end portion on the side edge 16 a side. It is fixed in the state. Here, being fixed means being mounted. The mounting positions of the diode bridge 21 and the switching element 22 are not limited to the positions illustrated in FIG. 3 and the like, and may be other positions. The end of the circuit board 16 is a part of the surface of the circuit board 16 close to any of the side edges 16a to 16d, and electronic components (in this example, the diode bridge 21 and the This is the portion that can connect the end face of the switching element 22) to the side wall of the case 33 so as to allow heat conduction. The side wall portion of the case 33 will be described later.

  Specifically, the diode bridge 21 is a SIP electronic component having four terminals. SIP is an abbreviation for “Single Inline Package”. The diode bridge 21 is mounted on the surface of the circuit board 16 by having four terminals inserted into through holes provided in the circuit board 16 and soldered. The package of the diode bridge 21 is provided with a hole 21a through which a fixing screw 43 is passed.

  The switching element 22 is an electronic component of a TO package having three terminals. TO is an abbreviation for “Transistor Outline”. The switching element 22 is mounted on the surface of the circuit board 16 by inserting and soldering three terminals into through holes provided in the circuit board 16. In the package of the switching element 22, a hole 22 a for passing a fixing screw 45 is provided.

  As shown in FIGS. 8 and 12, the end face of the diode bridge 21 and the switching element 22 mounted on the end portion of the circuit board 16 (that is, in FIGS. 8 and 12) when the circuit board 16 is viewed in plan view. The rear surface is slightly outside the end of the circuit board 16 (in this example, the side edge 16a). Note that the end faces of the diode bridge 21 and the switching element 22 mounted on the circuit board 16 can be connected to the side wall of the case 33 so as to be capable of conducting heat (ie, the same positions as the ends of the circuit board 16 (that is, Level), or may be slightly inside the edge of the circuit board 16.

An IPM 23 is mounted on the surface opposite to the surface of the circuit board 16 (hereinafter referred to as the back surface).
Specifically, the IPM 23 is a DIP electronic component having a plurality of terminals 31. DIP is an abbreviation for “Dual Inline Package”. The plurality of terminals 31 include the power supply terminal 31a and the ground terminal 31b described above. The IPM 23 is mounted on the back surface of the circuit board 16 by inserting and soldering a plurality of terminals 31 arranged in two rows into through holes provided in the circuit board 16.

  The circuit board 16 is provided with two holes 37 and 38 through which the two screws 35 and 36 pass. The screws 35 and 36 are screws for fixing the IPM 23 mounted on the circuit board 16 to the case 33. Of the holes 37, 38, the hole 38 closer to the side edge 16 c can be said to be a notched part opened on the side edge 16 c side, but in the sense that it is a part protruding from the front surface to the back surface of the circuit board 16. It is. The package of the IPM 23 is provided with notches 23a and 23b through which the screws 35 and 36 are passed.

  Further, after the circuit board 16 is accommodated in the case 33, the circuit board 16 is inserted into a space between the back surface of the circuit board 16 and the case 33 (ie, a sealing material such as urethane resin or epoxy resin). A hole 39 for filling the (stopping material) is provided. Similar to the hole 38, the hole 39 can be said to be a cutout portion that is open on the side edge 16 d side, but is a hole in the sense of a portion that protrudes from the front surface to the back surface of the circuit board 16.

The holes 37 and 38 for passing the screws 35 and 36 are also used as holes for filling the mold material.
As shown in FIGS. 3 to 9, 14, and 15, the case 33 includes a bottom 33 e that faces the back surface of the circuit board 16 and four side wall parts 33 a to 33 d that surround the side edges 16 a to 16 d of the circuit board 16. And comprising. The side wall part 33a is a side wall part that is outside the side edge 16a, the side wall part 33b is a side wall part that is outside the side edge 16b, and the side wall part 33c is a side wall part that is outside the side edge 16c. The sidewall portion 33d is a sidewall portion that is outside the side edge 16d.

  A portion 41 of the side wall portion 33a that faces the diode bridge 21 and the switching element 22 mounted on the circuit board 16 is a portion that is connected to the diode bridge 21 and the switching element 22 so as to be capable of conducting heat (hereinafter, referred to as “a portion”) (Thermal connection wall portion) 41. The thermal connection wall portion 41 corresponds to a specific portion. The diode bridge 21 and the switching element 22 correspond to specific electronic components that are radiated by the case 33.

  The heat connection wall portion 41 has a height from the bottom portion 33e larger than other portions of the side wall portion 33a and the other side wall portions 33b to 33d. That is, among the side wall portions 33a to 33d, the heat connection wall portion 41 is higher in height from the bottom portion 33e than the other portions. A height H1 illustrated in FIG. 14 indicates the height of the lowest portion of the thermal connection wall portion 41 with reference to the upper surface of the bottom portion 33e. Further, the height H2 shown in FIG. 14 indicates the height of the side wall portion 33a other than the heat connection wall portion 41 and the other side wall portions 33b to 33d with reference to the upper surface of the bottom portion 33e. The height H1 is larger than the height H2.

  Furthermore, the thermal connection wall portion 41 has a thickness larger than that of the other portions of the side wall portion 33a and the other side wall portions 33b to 33d. That is, among the side wall portions 33a to 33d, the thermal connection wall portion 41 is thicker than the other portions. A thickness T1 illustrated in FIG. 15 indicates the thickness of the thermal connection wall portion 41. Moreover, thickness T2 shown in FIG. 15 has shown each thickness of parts other than the thermal connection wall part 41 in the side wall part 33a, and other side wall parts 33b-33d. And thickness T1 is larger than thickness T2.

  In addition, compared with the other part in the side wall part 33a, and the other side wall parts 33b-33d, the heat connection wall part 41 may have the same thickness and a large height, or the same height and the same thickness. May be large. Further, the heat connection wall portion 41 may have the same height and thickness compared to other portions of the side wall portion 33a and the other side wall portions 33b to 33d.

  The thermal connection wall 41 is provided with a fixing hole 44 for fixing the diode bridge 21 to the thermal connection wall 41 with a screw 43. The fixing hole 44 is a screw hole into which the screw 43 is screwed. Further, the heat connection wall 41 is provided with a fixing hole 46 for fixing the switching element 22 to the heat connection wall 41 with a screw 45. The fixing hole 46 is a screw hole into which the screw 45 is screwed.

  The case 33 is configured so that the surface of the IPM 23 opposite to the circuit board 16 side (hereinafter referred to as an outer surface) and the bottom 33e are connected to be able to conduct heat in a state in which the circuit board 16 is accommodated. . The IPM 23 corresponds to another electronic component that is radiated by the case 33.

  As shown in FIG. 4, in the bottom 33e, a portion facing the IPM 23 and connected to the IPM 23 so as to conduct heat (hereinafter referred to as a heat connection portion) 49 is opposite to the circuit board 16 side (that is, the side) Recessed on the lower side).

  In the state where the circuit board 16 is accommodated in the case 33, a minute gap is formed between the outer surface of the IPM 23 and the heat connection portion 49 in which heat dissipation grease can be interposed. The heat dissipation grease is grease for facilitating heat transfer from the electronic component to the case 33. That is, in the present embodiment, the IPM 23 and the thermal connection portion 49 are connected so as to be able to conduct heat via the heat radiation grease.

  The bottom 33e is provided with fixing holes 51 and 52 for fixing the IPM 23 to the bottom 33e with screws 35 and 36. The fixing holes 51 and 52 are screw holes into which the screws 35 and 36 are screwed.

  As shown in FIGS. 5 to 7, 9, and 14, heat radiation fins 54 are provided on a surface (that is, a lower surface) opposite to the heat connection portion 49 in the bottom 33 e. The radiation fin 54 includes a plurality of protrusions 54a arranged in parallel. The controller 15 is accommodated in the controller accommodating portion 9 so that the longitudinal direction of the protrusion 54a is parallel to the direction of the wind generated by the fan. The radiating fin 54 may be provided not only on the bottom 33e but also on at least one outer surface of the side walls 33a to 33d. Moreover, the radiation fin 54 may not be provided in the bottom part 33e, but may be provided in the at least 1 outer surface of the side wall parts 33a-33d. That is, the radiation fin 54 can be provided on at least one surface of the case 33.

  As shown in FIGS. 3, 4, 8, and 15, each of the side wall portions 33 a and 33 c is provided with a support portion 56 that contacts the back surface of the circuit board 16 and supports the circuit board 16. The lower side of the support portion 56 reaches the bottom portion 33e. The height of the support portion 56 from the bottom portion 33e is set as small as possible as long as electronic components other than the IPM 23 mounted on the back surface of the circuit board 16 do not hit the bottom portion 33e. Of course, the height shown in FIG. Smaller than H2.

  Each of the side wall portions 33b and 33d is provided with a restricting portion 58 that abuts the side edges 16b and 16d of the circuit board 16 and restricts the movement of the circuit board 16 in the left-right direction. The limiting portion 58 is provided so as to reach the bottom portion 33e from the upper ends of the side wall portions 33b and 33d.

  As shown in FIGS. 3, 4, 8, 15, and 16, guide portions 70 that contact the side edges 16 c of the circuit board 16 are provided at both corners of the side wall portion 33 c. Yes. The guide part 70 is a protrusion provided so as to reach the bottom part 33e from the upper end of the side wall part 33c. Furthermore, the guide part 70 is formed so that the protrusion amount to the side wall part 33a side (namely, the heat connection wall part 41 side) increases as it goes from the upper side to the lower side (namely, the bottom part 33e side).

  On the other hand, as shown in FIGS. 3, 4, 8, and 10 to 13, on the side edge 16 c of the circuit board 16, both corner portions (hereinafter referred to as corner portions) 72 that are in contact with the guide portion 70 are circuit The substrate 16 is cut out in a plan view.

[1-4. Controller assembly procedure]
An example of the procedure for assembling the controller 15 will be described.
First, before accommodating the circuit board 16 in the case 33, an appropriate amount of heat-dissipating grease is applied to the back surface of the diode bridge 21 and the switching element 22 and the outer surface of the IPM 23. The back surfaces of the diode bridge 21 and the switching element 22 are surfaces facing the side wall portion 33 a when the circuit board 16 is accommodated in the case 33, that is, a surface on the side facing the thermal connection wall portion 41. It is.

Next, the following accommodating operation is performed as an operation for accommodating the circuit board 16 in the case 33.
As indicated by the dotted arrow in FIG. 4, the circuit board 16 is brought closer to the case 33 from above the case 33 so as to be parallel to the bottom 33 e of the case 33.

  As shown in FIG. 17, among the side edges 16 a to 16 d of the circuit board 16, the corner 72 of the side edge 16 c that is opposite to the mounting position of the diode bridge 21 and the switching element 22 is guided in the case 33. It is made to contact | abut near the upper end of the part 70. FIG. At this time, a gap D larger than the thickness of the heat radiation grease applied to the back surface is generated between the back surface of the diode bridge 21 and the switching element 22 and the heat connection wall portion 41 of the case 33. In addition, illustration of thermal radiation grease is abbreviate | omitted.

  Thereafter, the circuit board 16 is moved downward while the corner 72 of the side edge 16 c of the circuit board 16 is brought into contact with the guide part 70. That is, the circuit board 16 is stored in the case 33. As the circuit board 16 goes downward, the distance between the back surface of the diode bridge 21 and the switching element 22 and the thermal connection wall 41 decreases.

  When the back surface of the circuit board 16 comes into contact with the support portion 56 of the case 33, the circuit board 16 is accommodated in the case 33 as shown in FIG. In this state, there is a minute gap between the back surface of the diode bridge 21 and the switching element 22 and the heat connection wall portion 41 in which heat dissipation grease can be interposed. The diode bridge 21 and the switching element and the thermal connection wall 41 are connected to each other through heat radiation grease so as to be able to conduct heat.

  When the above housing operation is completed, each of the diode bridge 21 and the switching element 22 is fixed to the thermal connection wall 41 with screws 43 and 45 as shown in FIG. Specifically, the diode bridge 21 is fixed to the thermal connection wall 41 by inserting the screw 43 into the hole 21 a of the diode bridge 21 and screwing into the fixing hole 44 of the thermal connection wall 41. Similarly, the switching element 22 is fixed to the thermal connection wall 41 by inserting the screw 45 into the hole 22 a of the switching element 22 and screwing into the fixing hole 46 of the thermal connection wall 41.

Further, the screws 35 and 36 are inserted from the holes 37 and 38 of the circuit board 16 and screwed into the fixing holes 51 and 52 of the case 33, thereby fixing the IPM 23 to the case 33.
The circuit board 16 is fixed to the case 33 by fixing the diode bridge 21, the switching element 22, and the IPM 23 mounted on the circuit board 16 to the case 33.

  Next, the molding material is filled into the space between the back surface of the circuit board 16 and the case 33 from the three holes 37, 38, 39 provided in the circuit board 16. Finally, in the case 33, the molding material is also filled in the portion above the circuit board 16.

  The mold material filled in the case 33 may improve the vibration proof property, dust proof property, and drip proof property of the circuit board 16, or may improve the insulation properties of electronic parts such as the IPM 23 mounted on the circuit board 16. it can.

  Further, since the holes 37, 38, 39 of the circuit board 16 are provided at different positions in the circuit board 16, the molding material can be uniformly injected into the space between the back surface of the circuit board 16 and the case 33. it can. The number of holes into which the mold material can be injected is not limited to three, but may be four or more, and may be one or two.

[1-5. effect]
According to the embodiment described in detail above, the following effects can be obtained.
(1) The diode bridge 21 and the switching element 22 that are electrically connected to the circuit board 16 by being mounted on the circuit board 16 and the thermal connection wall 41 in the side wall 33a of the case 33 can conduct heat. It is connected to the.

  For this reason, the heat generated in the diode bridge 21 and the switching element 22 is transmitted to the thermal connection wall 41 and then transmitted to the entire case 33 or released from the case 33 to the atmosphere or the like. Since the heat capacity and area of the case 33 are large, the heat dissipation of the diode bridge 21 and the switching element 22 can be ensured. In addition, regarding the heat dissipation of the diode bridge 21 and the switching element 22, it is not necessary to provide a metal heat dissipation member on the circuit board 16. Therefore, the space of the circuit board 16 can be used effectively while ensuring the heat dissipation performance of the diode bridge 21 and the switching element 22.

  (2) Among the side wall portions 33a to 33d of the case 33, the heat connection wall portion 41 has a height from the bottom portion 33e larger than other portions. For this reason, the heat capacity and area of the heat connection wall 41 can be increased. Therefore, the heat dissipation effect of the diode bridge 21 and the switching element 22 can be improved.

  (3) Of the side wall portions 33 a to 33 d of the case 33, the heat connection wall portion 41 is thicker than the other portions. For this reason, the heat capacity of the thermal connection wall 41 can be increased. Therefore, the heat dissipation effect of the diode bridge 21 and the switching element 22 can be improved.

  (4) Of the side wall portions 33a to 33d of the case 33, the side wall portion 33c facing the heat connecting wall portion 41 has a guide with a larger amount of protrusion toward the heat connecting wall portion 41 side from the upper side to the bottom portion 33e side. A portion 70 is provided. For this reason, the circuit board 16 can be accommodated in the case 33 while the distance between the back surface of the diode bridge 21 and the switching element 22 and the thermal connection wall portion 41 is gradually reduced by performing the accommodation operation described above. . Therefore, when the circuit board 16 is accommodated in the case 33, it is possible to suppress the inconvenience that the back surface of the diode bridge 21 and the switching element 22 and the thermal connection wall portion 41 are rubbed and the heat radiation grease is scraped off. it can. The heat radiation grease may be applied toward the heat connection wall portion 41. Even in this case, the same effect can be obtained.

  (5) The guide part 70 of the case 33 is a protrusion having a longitudinal direction from the upper side to the bottom 33e side. In the circuit board 16, the corner 72 that contacts the guide part 70 is a part that is cut out in a state in which the circuit board 16 is viewed in plan. For this reason, the guide part 70 will be in the state which enters into the corner part 72 notched in the circuit board 16. FIG. Therefore, the area of the circuit board 16 can be increased. The notched corner 72 may not be provided, but in that case, the width in the direction perpendicular to the side edges 16a and 16c of the circuit board 16 (that is, the length of the side edges 16b and 16d). ) Is slightly smaller than when the cut-out corner 72 is provided.

  (6) The IPM 23 and the bottom 33e of the case 33 are connected to be able to conduct heat. For this reason, the heat generated in the IPM 23 is transmitted to the bottom 33e of the case 33, and then transmitted to the entire case 33 or released from the case 33 to the atmosphere or the like. Therefore, it is not necessary to provide a metal heat dissipating member on the circuit board 16 for the heat dissipation of the IPM 23. For this reason, the space of the circuit board 16 can be used more effectively.

  (7) In the bottom 33e of the case 33, the thermal connection portion 49 connected to the IPM 23 so as to be able to conduct heat is recessed on the side opposite to the circuit board 16 side. For this reason, the distance between the circuit board 16 and the portion of the bottom 33e that is not the thermal connection portion 49 can be reduced. As a result, the height of the side wall portions 33a to 33d of the case 33 can be reduced.

  (8) On the bottom 33 e of the case 33, heat radiating fins 54 are provided on the surface opposite to the heat connection portion 49. For this reason, the heat dissipation effect of the IPM 23 can be improved. Moreover, since the longitudinal direction of the protrusion 54a in the radiation fin 54 is parallel to the direction of the wind generated by the above-described fan, the heat radiation effect is further improved.

[1-6. Other matters]
The matters that are not shown in the drawings will be described.
[1-6-1]
As shown in FIG. 18, a lead wire 75 connected to the ground line Lg protrudes from the surface of the circuit board 16. A well-known round terminal 76 having a hole is attached to the tip of the lead wire 75. The round terminal 76 is electrically connected to the heat connection wall portion 41 of the case 33 by a screw 45 that fixes the switching element 22. That is, the screw 45 is inserted into the hole 22 a of the switching element 22 while being passed through the hole of the round terminal 76, and is screwed into the fixing hole 46 of the heat connection wall portion 41. For this reason, the case 33 is connected to the ground line Lg of the circuit board 16 via the screw 45 and the lead wire 75. That is, the case 33 has the same potential as the ground line Lg.

  Therefore, for example, static electricity and high frequency noise applied to the case 33 can be released to the ground line Lg. As a result, the electronic component mounted on the circuit board 16 can be prevented from being damaged due to static electricity or malfunction caused by high frequency noise. Further, it is possible to suppress the emission of noise from the circuit board 16 to the outside.

The round terminal 76 may be electrically connected to the thermal connection wall 41 not by the screw 45 but by the screw 43 that fixes the diode bridge 21.
[1-6-2]
As shown in FIG. 18, the capacitor 24 functioning as a snubber circuit and the current detection resistor 26 are mounted on the surface of the circuit board 16 in a region sandwiched between two groups of terminals 31 of the IPM 23. Yes. For this reason, the space of the circuit board 16 can be used effectively. In addition, the length of the wiring pattern that connects the power supply terminal 31a of the IPM 23 and the capacitor 24 and the length of the wiring pattern that connects the ground terminal 31b of the IPM 23 and the resistor 26 can be shortened. If there is a capacitor in parallel with the capacitor 24, the parallel capacitor can also be surface-mounted in a region sandwiched between the two groups of terminals 31 of the IPM 23.

[2. Other Embodiments]
As mentioned above, although embodiment of this indication was described, this indication is not limited to the above-mentioned embodiment, and can carry out various modifications.

[2-1]
As shown in FIG. 19, the fixing holes 44 and 46 provided in the thermal connection wall portion 41 may be elongated holes in the vertical direction instead of screw holes. In this case, the diode bridge 21 and the switching element 22 may be fixed to the thermal connection wall 41 with screws 43 and 45 and nuts. If comprised in this way, the position shift of the up-down direction of the diode bridge 21 and the switching element 22 in the state mounted in the circuit board 16 can be absorbed by a long hole.

Further, the fixing holes 44 and 46 may be elongated holes in the left-right direction.
[2-2]
A temperature sensor (for example, a thermistor) for detecting the temperature of the diode bridge 21 may be attached to the diode bridge 21 itself or the thermal connection wall portion 41. With this configuration, the temperature of the diode bridge 21 can be detected with high accuracy. For example, when the microcomputer 20 determines that the temperature of the diode bridge 21 is equal to or higher than the overheat determination value based on a signal from the temperature sensor, the microcomputer 20 performs a process for forcibly stopping the operation of the motor 19. Can do. Further, the temperature sensor may be attached to the switching element 22 itself or the thermal connection wall portion 41.

[2-3]
The diode bridge 21 and the switching element 22 and the thermal connection wall 41 may be configured to be in direct contact with each other, or may be connected so as to be able to conduct heat via a resin having thermal conductivity and elasticity. Similarly, the IPM 23 and the bottom 33e of the case 33 may be configured to be in direct contact with each other, or may be connected to be able to conduct heat through a resin having thermal conductivity and elasticity.

[2-4]
The electronic component connected to the thermal connection wall portion 41 so as to be capable of conducting heat may be either the diode bridge 21 or the switching element 22, or one or more different from the diode bridge 21 and the switching element 22. Electronic components may be used. For example, when there is a switching element provided in series with respect to the capacitor 18 as an electronic component mounted on the circuit board 16, the switching element may be connected to the thermal connection wall portion 41 so as to be able to conduct heat. The electronic component connected to the bottom 33e of the case 33 so as to be capable of conducting heat may be one or more electronic components different from the IPM 23.

[2-5]
The electronic component connected to the heat connection wall portion 41 so as to be capable of conducting heat may be an electronic component electrically connected to the circuit board 16 with a lead wire. Similarly, the electronic component connected to the bottom portion 33e so as to be capable of conducting heat may be an electronic component electrically connected to the circuit board 16 through a lead wire.

[2-6]
Of the portion of the case 33, a portion and a portion other than the portion may be formed separately.

[2-6-1]
For example, in the example shown in FIG. 20, among the portion of the case 33, the side wall portion 33 a including the heat connection wall portion 41 and other portions, that is, the side wall portions 33 b to 33 d and the bottom portion 33 e (hereinafter, case main body portion 80). And are formed as separate bodies. In FIG. 20, the side wall 33d is not shown.

  In the case of the example shown in FIG. 20, the case 33 can be completed by fixing the side wall 33 a to the case body 80 using a fixing member such as a screw 81 or a heat conductive adhesive.

  Further, as a procedure for assembling the controller 15, for example, any of the following <a> to <c> can be considered. In any of the examples, an appropriate amount of heat radiation grease is applied in advance to the back surfaces of the diode bridge 21 and the switching element 22.

<a> After the case 33 is completed, the circuit board 16 is accommodated in the completed case 33. That is, the same procedure as in the above-described embodiment is performed.
<B> Before completing the case 33, the side wall 33 a is attached to the diode bridge 21 and the switching element 22 mounted on the circuit board 16 by the screws 43 and 45 described above. Specifically, the screws 43 and 45 are inserted into the holes 21a and 22a of the diode bridge 21 and the switching element 22, respectively, and fixed to the fixing holes 44 and 46 provided in the thermal connection wall 41 in the side wall 33a. The side wall 33a is fixed to the diode bridge 21 and the switching element 22 by screwing.

  Then, the circuit board 16 with the side wall 33a attached is accommodated in the case main body 80, and then the side wall 33a is fixed to the case main body 80 using a fixing member such as a screw 81 or an adhesive. To do. The circuit board 16 may be accommodated in the case main body 80 from above the case main body 80, but the case main body 80 has an opening that is planned to be closed by the side wall 33 a. May be accommodated.

<C> Before the case 33 is completed, the circuit board 16 in a state where the side wall 33 a is not attached is accommodated in the case main body 80.
Then, the side wall 33a is fixed to the case main body 80 by using a fixing member such as a screw 81 or an adhesive, and then the side wall 33a, the diode bridge 21 and the switching element 22 are fixed by screws 43 and 45. Fix it. Conversely, the side wall 33 a and the case main body 80 may be fixed after the side wall 33 a and the diode bridge 21 and the switching element 22 are fixed by the screws 43 and 45.

[2-6-2]
On the other hand, although illustration is omitted, for example, in the portion of the case 33, the thermal connection wall portion 41 that is a part of the side wall portion 33a and other portions may be formed separately. Here, a portion other than the thermal connection wall portion 41 in the portion of the case 33 is referred to as a case main body portion. In the case of this example, the case 33 can be completed by fixing the heat connection wall 41 to the case body using a fixing member such as a screw or a heat conductive adhesive.

  Further, as a procedure for assembling the controller 15, for example, any of the following <A> to <C> can be considered. In any of the examples, an appropriate amount of heat radiation grease is applied in advance to the back surfaces of the diode bridge 21 and the switching element 22.

<A> After the case 33 is completed, the circuit board 16 is accommodated in the completed case 33. That is, the same procedure as in the above-described embodiment is performed.
<B> Before the case 33 is completed, the thermal connection wall 41 is attached to the diode bridge 21 and the switching element 22 mounted on the circuit board 16 with the screws 43 and 45 described above.

  Then, the circuit board 16 with the heat connection wall 41 attached is accommodated in the case main body, and then the heat connection wall 41 is attached to the case main body using a fixing member such as a screw or an adhesive. Fix it.

<C> Before the case 33 is completed, the circuit board 16 to which the thermal connection wall portion 41 is not attached is accommodated in the case main body portion.
Then, the thermal connection wall 41 is fixed to the case body using a fixing member such as a screw or an adhesive, and then the thermal connection wall 41, the diode bridge 21, and the switching element 22 by screws 43 and 45. And fixing. Conversely, the thermal connection wall 41 and the diode bridge 21 and the switching element 22 may be fixed by screws 43 and 45, and then the thermal connection wall 41 and the case main body may be fixed.

[2-7]
Any of the side wall portions 33a to 33d in the case 33 and the specific electronic component to be radiated are connected to the case 33 through a metal radiating member (hereinafter referred to as a heat sink member) so as to be thermally conductive. Also good. When configured in this way, it is not necessary to increase the size of the heat sink member in order to ensure heat dissipation. That is, the heat sink member can be reduced in size. Therefore, the space of the circuit board 16 can be used effectively while ensuring the heat dissipation of the electronic component.

[2-7-1]
For example, in the example shown in FIG. 21, the thermal connection wall 41 shown in FIG. 3, FIG. 4, etc. is not formed on the side wall 33 a of the case 33. That is, the height and width of the side wall 33a are the same as the side wall 33c facing the side wall 33a. The electronic component 85 to be radiated mounted on the end portion of the circuit board 16 and the side wall portion 33a are connected to each other through a heat sink member 83 that is separate from the case 33 so as to conduct heat.

  The heat sink member 83 is formed in the same shape as the heat connection wall 41 shown in FIGS. 3 and 4. In addition, the front surface of the portion of the heat sink member 83 located above the side wall 33a and the back surface of the electronic component 85 (that is, the rear surface) directly or thermally conducts heat radiation grease or the like. It is in contact through the material. In addition, the lower surface of the heat sink member 83 located above the side wall 33a and the upper surface of the side wall 33a are in contact with each other directly or through a heat conductive material such as heat radiation grease. doing. Further, in the heat sink member 83, the front surface of the portion located rearward of the side wall portion 33a and the rear surface of the side wall portion 33a are in direct contact or through a heat conductive material such as heat radiation grease. doing.

  In this example, the electronic component 85 corresponds to a specific electronic component. And in the side wall part 33a, the part 86 which contacts the heat sink member 83 is equivalent to the specific part connected with the specific electronic component 85 so that heat conduction is possible.

Further, for example, the heat sink member 83 may have a shape of only the portion 83a in the forward direction from the dotted line in FIG.
Further, for example, the heat sink member 83 may have a shape of only the portion 83b in the rearward direction with respect to the dotted line in FIG. In this case, the rear surface of the electronic component 85 can be brought into contact with the heat sink member 83 by appropriately bending the terminal of the electronic component 85.

Further, for example, the heat sink member 83 may be fixed to the case 33 with a screw, a heat conductive adhesive, or the like.
[2-7-2]
For example, also in the example shown in FIG. 22, the height and width of the side wall 33a in the case 33 are the same as the side wall 33c, as in the example of FIG. The heat dissipating electronic component 85 mounted on the end of the circuit board 16 and the side wall portion 33a are directly or directly on the back surface of the electronic component 85 and the front surface of the side wall portion 33a or a heat conducting material such as heat dissipating grease. The heat-sink member 87 that is in contact with each other is connected to be able to conduct heat. The heat sink member 87 is formed in a plate shape, for example. In this example, a portion 88 in contact with the heat sink member 87 in the side wall portion 33a corresponds to a specific portion connected to the specific electronic component 85 so as to be able to conduct heat.

Further, for example, the heat sink member 87 may be fixed to the case 33 with a screw, a heat conductive adhesive, or the like.
[2-8]
The electric working machine is not limited to Marunoco. For example, an electric hammer, an electric hammer drill, an electric drill, an electric driver, an electric wrench, an electric reciprocating saw, an electric jigsaw, an electric cutter, an electric chain saw, an electric canna, and an electric hammering machine are included. It may be a nailing machine, an electric hedge trimmer, an electric lawn mower, an electric lawn clipper, an electric brush cutter, an electric cleaner, an electric blower, a grinder, or the like.

[2-9]
A plurality of functions of one constituent element in the embodiment may be realized by a plurality of constituent elements, or a single function of one constituent element may be realized by a plurality of constituent elements. Further, a plurality of functions possessed by a plurality of constituent elements may be realized by one constituent element, or a single function realized by a plurality of constituent elements may be realized by one constituent element. Moreover, you may abbreviate | omit a part of structure of the said embodiment. Further, at least a part of the configuration of the embodiment or the modification may be added to or replaced with the configuration of the other embodiment. In addition, all the aspects included in the technical idea specified from the wording described in the claims are embodiments of the present disclosure. Moreover, this indication is also realizable with various forms, such as the thermal radiation method of an electrically-driven working machine.

  DESCRIPTION OF SYMBOLS 1 ... Electric working machine, 2 ... Base, 3 ... Main-body part, 4 ... Saw blade, 5 ... Saw blade case, 6 ... Cover, 7 ... Main body casing, 7a ... 1st ventilation port, 7b ... 2nd ventilation port, 8 DESCRIPTION OF SYMBOLS ... Motor accommodating part, 9 ... Controller accommodating part, 10 ... Handle, 11 ... Operation switch, 12 ... Power supply cord, 13 ... AC power supply, 14 ... Fuse, 15 ... Controller, 16 ... Circuit board, 16a-16d ... Side edge, 18 ... capacitor, 19 ... motor, 20 ... microcomputer, 21 ... diode bridge, 21a, 22a ... hole, 22 ... switching element, 23 ... IPM, 23a, 23b ... notch, 24 ... capacitor, 26 ... resistor, 27 DESCRIPTION OF SYMBOLS ... Current detection circuit, 28 ... Power supply circuit, 29 ... Drive signal generation circuit, 30 ... Protection circuit, 31 ... Terminal, 31a ... Power supply terminal, 31b ... Ground terminal, 33 ... Case, 33a- 3d ... side wall, 33e ... bottom, 35, 36, 43, 45 ... screw, 37, 38, 39 ... hole, 41 ... heat connection wall, 44, 46 ... fixing hole, 49 ... heat connection, 51, 52 ... Fixing hole, 54 ... Radiation fin, 54a ... Projection, 56 ... Supporting part, 58 ... Restriction part, 70 ... Guide part, 72 ... Corner part, 75 ... Lead wire, 76 ... Round terminal, 80 ... Case Body part 81 ... Screw 83, 87 Heat sink member 85 ... Electronic component 86, 88 ... Specific part connected to the electronic component so as to conduct heat, Lg ... Ground line, Lp ... Power line, Q1-Q6 ... Switching element.

Claims (9)

An electric working machine,
A motor as a power source of the electric working machine;
A circuit board constituting a controller for controlling the motor;
A metal case in which the circuit board is accommodated, and
The case is
A bottom portion facing a back surface, which is one surface of the circuit board, and a side wall portion surrounding a side edge of the circuit board,
One or more specific electronic components electrically connected to the circuit board and a specific portion of the side wall portion are connected so as to be able to conduct heat,
Electric working machine. The electric working machine according to claim 1,
Among the side wall portions, the specific portion has a height higher than the bottom portion than other portions.
Electric working machine. The electric working machine according to claim 1 or 2,
Of the side wall, the specific portion is thicker than other portions.
Electric working machine. The electric working machine according to any one of claims 1 to 3,
The specific electronic component is fixed in an upright state at an end of the circuit board,
The specific part-side surface of the specific electronic component and the specific part are connected so as to be able to conduct heat,
Among the side wall portions, the side wall portion facing the specific portion is a guide portion that contacts the side edge of the circuit board, and goes from the upper side opposite to the bottom side to the bottom side. A guide portion is provided that increases the amount of protrusion toward the specific portion.
Electric working machine. The electric working machine according to claim 4,
The guide portion is a ridge having a longitudinal direction from the upper side to the bottom side,
In the circuit board, the part that contacts the guide part is a part that is cut out in a state in plan view of the circuit board.
Electric working machine. The electric working machine according to any one of claims 1 to 5,
Of the plurality of electronic components electrically connected to the circuit board, another electronic component which is an electronic component different from the specific electronic component, and the bottom portion are connected to be able to conduct heat,
Electric working machine. The electric working machine according to claim 6,
In the bottom portion, a thermal connection portion that is a portion that is connected to the other electronic component so as to be capable of conducting heat is recessed on the side opposite to the circuit board side,
Electric working machine. The electric working machine according to claim 6 or claim 7,
In the bottom portion, a heat radiating fin is provided on the surface opposite to the thermal connection portion.
Electric working machine. The electric working machine according to any one of claims 1 to 7,
Radiation fins are provided on at least one surface of the case,
Electric working machine.