Control module for power tool, and power tool

Abstract

To provide a control module that can sufficiently dustproof or waterproof the space formed by the cover and the case.SOLUTION: A control module 10 includes: a box-shaped case 60, one side of which is open; and a circuit board 50 housed in the case 60. A microcomputer 51 and field effect transistors (FETs) 52 used for controlling a brushless motor of the power tool are mounted on the circuit board 50. The case 60 is movably connected with a trigger 20. The circuit board 50 is electrically connected with movable switches 30, which are mechanically linked to movement of the trigger 20. An opening of the case 60 is partially covered with a cover 70. The cover 70 covers a portion of the circuit board 50 and the movable switches 30. The control module further includes bonded parts 14, which weld or bond the cover 70 and the case 60. The bonded parts 14 form an enclosed space 13, which encloses the movable switches 30.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a power tool and a control module for the power tool. The control module has, for example, a circuit board and a trigger associated with controlling the motor of the power tool. [Background technology]

[0002] The power tool described in Patent Document 1 has a brushless motor and a control module. The control module has a case that is open at the top and a circuit board that is housed in the case. The circuit board is provided with a field effect transistor (FET) that is used to control the brushless motor. The control module also has a trigger and an actuator that moves in conjunction with the operation of the trigger. The actuator is connected to the circuit board and is covered by a cover. The cover is connected to the case by a snap fit. The actuator is provided in the closed space formed by the cover and the case, and the actuator is protected. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] European Patent No. 2946886 Summary of the Invention [Problem to be solved by the invention]

[0004] However, snap fits often leave gaps between the cover and the case, which can prevent the enclosed space from being sufficiently dustproof or waterproof. As a result, dust or water entering the enclosed space can cause poor electrical continuity at the contacts. Therefore, a control module that can adequately protect the space formed by the cover and the case from dust or water is needed. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, a control module for a power tool includes a box-shaped case with one open side and a circuit board housed in the case. The circuit board is equipped with a microcomputer and a field effect transistor (FET) used to control a brushless motor of the power tool. An operating member is movably connected to the case. A movable switch that is mechanically linked to the movement of the operating member is connected to the circuit board. A cover partially covers the opening of the case. The cover covers a portion of the circuit board and the movable switch. An adhesive is provided to weld or bond the cover and the case. The adhesive forms an enclosed space that encloses the movable switch.

[0006] The adhesive joint melts and welds at least a portion of the cover and the case together, or bonds the cover and the case together using an adhesive. Therefore, the adhesive joint fills the gap between the cover and the case. An enclosed space is formed between the cover and the case. The enclosed space is more dustproof and waterproof than a closed space where the cover and the case are connected to each other by, for example, a snap fit. The movable switch is protected by the enclosed space. Thus, the movable switch is less likely to experience poor contact with dust or water. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is a right side view of the power tool with the right housing removed. [Figure 2] FIG. 2 is an exploded perspective view of the control module disassembled from the power tool. [Figure 3] FIG. 2 is a right side view of the control module. [Figure 4] FIG. 2 is a perspective view of a control module. [Figure 5] FIG. 2 is an exploded perspective view of the control module. [Figure 6] FIG. 6 is an exploded perspective view of FIG. 5 as seen from the left side. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 3. [Figure 8]FIG. 10 is a view of the cover and trigger from the left side. [Figure 9] FIG. 9 is a view corresponding to FIG. 8 and showing a state in which the trigger is pulled. [Figure 10] FIG. 2 is an enlarged view of the upper region of the circuit board. [Figure 11] FIG. 5 is a perspective view corresponding to FIG. 4, showing a state in which the FET is covered with a heat sink. [Figure 12] FIG. 10 is a perspective view showing a heat sink according to another embodiment. [Figure 13] FIG. 10 is a perspective view showing a heat sink according to another embodiment. [Figure 14] FIG. 10 is a perspective view showing a heat sink according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] According to another feature of the present disclosure, the microcomputer and the FET are mounted on the circuit board at positions that avoid the enclosed space, so that when the microcomputer and the FET generate heat, the heat can be effectively dissipated.

[0009] According to another feature of the present disclosure, the operation and stop of the brushless motor are switched by moving a movable switch linked to an operating member. Therefore, the operation and stop of the brushless motor are switched by operating the operating member.

[0010] According to another feature of the present disclosure, the movable switch includes a power switch and a variable speed switch. The power switch connects and disconnects the brushless motor to and from the battery. The variable speed switch controls the output of the brushless motor according to the amount of movement of the operating member. Therefore, the power switch and the variable speed switch are each variable by operating the operating member. The movable switch may include a control switch that controls the operation of a microcomputer. The microcomputer may, for example, recognize an input from the control switch and turn on a lighting device of the power tool. Therefore, the lighting device can be reliably turned on by operating the operating member.

[0011] According to another feature of the present disclosure, the case has a case bottom wall and a case peripheral wall extending upright from a peripheral edge of the case bottom wall. The cover has a cover bottom wall and a cover peripheral wall extending upright from a peripheral edge of the cover bottom wall. The adhesive portion welds or bonds a case-facing surface of the case peripheral wall and a cover-facing surface of the cover peripheral wall that face each other in the extending direction to each other. Thus, the opposing surfaces of the case peripheral wall and the cover peripheral wall are welded or bonded to each other.

[0012] According to another feature of the present disclosure, the cover has guide pieces that extend beyond the cover-facing surface of the cover peripheral wall toward the case and pass between the case peripheral wall and the side surface of the circuit board. The guide pieces fit between the circuit board and the case peripheral wall. Therefore, the cover is stably held relative to the circuit board and the case by the guide pieces. The adhesive portion may be formed by welding or adhering the end of the guide piece to the case.

[0013] According to another feature of the present disclosure, a cover is provided on one end of the case. A wall portion located on the other end of the cover's peripheral wall extends into the interior of the case. The extended wall portion of the cover and the circuit board are bonded by a seal portion. The other end of the case that is not covered by the cover is covered with a resin mold. Therefore, the electronic components on the other end of the case are protected from dust or water by the resin mold. The resin mold is prevented from entering the enclosed space by the cover's peripheral wall and the seal portion. Thus, contact failure of each switch can be suppressed by the resin mold.

[0014] According to another feature of the present disclosure, the operating member is a trigger that is operated by pulling. The trigger has a rod that passes between the case and the cover, is connected to a movable switch in the enclosed space, and moves axially. Therefore, when the case and the cover are assembled, the rod is sandwiched between the case and the cover, and the rod slides axially relative to the case and the cover.

[0015] According to another feature of the present disclosure, dust-proof grease is provided between the rod and the case and between the rod and the cover, thereby preventing dust from entering the cover. A selector switch for switching the rotation direction of the brushless motor is also provided in the enclosed space. A selector bracket is connected to the selector switch through the gap between the case and the cover. Dust-proof grease is also provided between the selector bracket and the case, and between the selector bracket and the cover.

[0016] According to another feature of the present disclosure, the operating member is biased by a spring. The spring is disposed in the enclosed space. Therefore, the enclosed space prevents the spring from being easily deformed by dust or water.

[0017] According to another feature of the present disclosure, a movable switch is disposed on one end of the circuit board, and a microcomputer is mounted on the other end of the circuit board so as to be farther from the movable switch than the FET.

[0018] According to another feature of the present disclosure, the case has a case protrusion that protrudes toward the circuit board so as to avoid screws provided in the main body of the power tool. The circuit board has a board recess into which the case protrusion is inserted. The board recess determines the position of the circuit board relative to the case. Therefore, the case protrusion of the case serves both the function of avoiding screws and the function of positioning the circuit board.

[0019] According to another feature of the present disclosure, a capacitor for temporarily storing voltages applied to a controller and a motor of a power tool is provided on a circuit board. The capacitor is located outside the enclosed space. The capacitor is a relatively large component. Therefore, it is possible to avoid the cover becoming larger due to the capacitor. The capacitor has a capacitance of, for example, 100 μF to 1200 μF, preferably 500 μF to 1200 μF, and more preferably 1000 μF to 1200 μF.

[0020] According to another feature of the present disclosure, an FET is provided outside the cover on a surface of the circuit board facing the opening of the case. The FET is covered with a resin mold. Therefore, the FET is located outside the cover, which facilitates heat dissipation. The FET is also protected from dust and water by the resin mold.

[0021] According to another feature of the present disclosure, the FET includes a first FET and a second FET disposed along the circuit board at an angle of 80 to 100 degrees relative to the first FET. A heat sink is provided across the first FET and the second FET. Therefore, the heat sink can more efficiently dissipate heat from the first FET and the second FET.

[0022] According to another aspect of the present disclosure, the power tool has a grip extending from the tool body. A control module is disposed within the grip. A cover and an operating member are disposed on one end of the control module. The grip is relatively elongated, and the control module is also relatively long. The cover and the operating member are disposed on one end of the control module. Therefore, the control module has a component arrangement corresponding to the grip.

[0023] According to another feature of the present disclosure, the power tool includes a sensor board provided with a sensor for detecting the rotation speed of the brushless motor, and a first lead wire extends from the sensor board to a position outside the enclosed space of the circuit board, thereby allowing one end of the first lead wire to be easily attached to the circuit board.

[0024] According to another feature of the present disclosure, the power tool includes a lighting fixture, and a second lead wire extends from the lighting fixture to a location outside the enclosed space of the circuit board, thereby allowing one end of the second lead wire to be easily attached to the circuit board.

[0025] Next, one embodiment of the present invention will be described with reference to Figures 1 to 10. As shown in Figure 1, the power tool 100 is exemplified as a driver drill that rotates a removably attached tool bit 200. A user holds the power tool 100 in his / her hand and is positioned on the left side in Figure 1. In the following description, the side in front of the user is defined as the rear direction (user side), and the far side is defined as the front direction. The up / down direction and the left / right direction are defined based on the user.

[0026] As shown in FIG. 1, the power tool 100 has a tool body 1. The tool body 1 has a substantially cylindrical housing 1a. The housing 1a extends along a predetermined drive shaft 1b. The housing 1a accommodates a brushless motor 1c as a drive source and a drive mechanism 1d that drives a tool bit 200 using power from the brushless motor 1c. A mode switching ring 1g that switches the operating mode of the power tool 100 and a chuck 1h to which the tool bit 200 can be attached and detached are provided at the front end of the housing 1a. The mode switching ring 1g is rotatable around the drive shaft 1b.

[0027] The power tool 100 has two operating modes: a drill mode and a driver mode. The drill mode is an operating mode in which a drill bit, which is an example of the tool bit 200, is rotated to perform a drilling operation on a workpiece. The driver mode is an operating mode in which a driver bit, which is another example of the tool bit 200, is rotated to perform a fastening operation on a screw or the like. The operating mode of the power tool 100 can be switched by the user rotating the mode switching ring 1g.

[0028] As shown in Figures 1 and 2, a grip 2 that a user holds is provided at the bottom of the housing 1a. The grip 2 is approximately cylindrical. The grip 2 extends downward. The housing 1a and the grip 2 have a half-split structure that can be separated in the left-right direction. The left and right portions of the grip 2 are attached to each other with screws 2a. A cylindrical protrusion 2b is provided at the center of the grip 2 in the vertical direction, into which the screw 2a is threaded. A battery mounting portion 2c is provided at the bottom of the grip 2. A battery 3 can be removably attached to the battery mounting portion 2c. The battery 3 can be removed from the battery mounting portion 2c and repeatedly charged and used with a separately provided charger. The battery 3 functions as a power source that supplies power to the brushless motor 1c. The battery 3 can be attached to and detached from the battery mounting portion 2c by sliding it in the forward and backward directions. Specifically, the battery 3 is attached to the battery mounting portion 2c by sliding it backward (in the mounting direction) relative to the battery mounting portion 2c. The battery 3 is removed by sliding it forward (in the removal direction) relative to the battery attachment portion 2c. The battery 3 can be attached and detached substantially parallel to the movement direction of a trigger 20, which will be described later.

[0029] As shown in FIG. 1, the brushless motor 1c rotates upon receiving a signal from a control module 10 (described later). The brushless motor 1c rotates around a drive shaft 1b. The rotational output of the brushless motor 1c is transmitted to a drive mechanism 1d. The drive mechanism 1d has a reduction gear train 1e, a spindle (not shown), and a chuck 1h. The reduction gear train 1e amplifies the torque input from the brushless motor 1c and outputs it to the spindle. This causes the spindle to rotate around the drive shaft 1b. The chuck 1h is connected to the spindle so that it rotates integrally with it. Therefore, as the spindle rotates, the chuck 1h rotates coaxially with the spindle. This causes the tool bit 200 attached to the chuck 1h to rotate.

[0030] As shown in FIG. 2, the tool body 1 has one sensor board 4. The sensor board 4 has a sensor 4a such as a Hall IC. The sensor 4a detects the rotational position of a permanent magnet provided in the brushless motor 1c. This allows the sensor board 4 to detect the rotation speed of the brushless motor 1c. Therefore, the sensor board 4 can grasp the operating state of the brushless motor 1c. The power tool 100 also has a lighting device 5 that lights up when the tool body 1 is operating. The lighting device 5 lights up when it receives a signal from the control module 10.

[0031] As shown in FIG. 2, a control module 10 is provided inside the grip 2. The control module 10 is a module that integrally includes an operation unit 11 operated by a user and a control unit 12 that controls the operation of the power tool 100 through operation of the operation unit 11, etc. The control unit 12 has one circuit board 50. The circuit board 50 is provided with control components such as a microcomputer 51, a FET 52, and a capacitor 53. A plurality of lead wires 55 are also connected to the circuit board 50. Each lead wire 55 transmits or receives signals and current between the control components and the brushless motor 1c, the lighting fixture 5, etc.

[0032] As shown in Figure 2, the operating unit 11 has a trigger 20 that is pulled by the user's fingertip, and a movable switch 30 that switches on and off in response to the pulling movement of the trigger 20. The movable switch 30 has a power switch 35 that connects and disconnects the brushless motor 1c to the battery 3, a variable speed switch 33 that varies the rotation speed of the brushless motor 1c depending on the amount of pulling of the trigger 20, and a control switch 31 that turns the lighting device 5 on and off via a signal from a microcomputer 51. The movable switch 30 is connected to a circuit board 50 of the control unit 12, which allows the control unit 12 to grasp the operating state of the movable switch 30.

[0033] As shown in FIG. 2, the operation unit 11 has a changeover switch 40 that switches the rotation direction of the brushless motor 1c. The changeover switch 40 is connected via a changeover bracket 42 to a changeover button 41 that protrudes from the left and right sides of the housing 1a. The user operates the changeover button 41 by pressing it left or right with their fingertip. The changeover switch 40 is switched in conjunction with the pressing of the changeover button 41. The changeover switch 40 is connected to a circuit board 50 of the control unit 12. This allows the control unit 12 to grasp the operating state of the changeover switch 40.

[0034] As shown in FIG. 2 , the control module 10 includes a case 60 that houses the operating unit 11 and the control unit 12 together, and a cover 70 that fits over the upper region of the case 60. The cover 70 is integrally attached to the case 60 by ultrasonic welding. As a result, the cover 70 tightly covers the upper region of the case 60. As a result, the control module 10 has an enclosed space 13 formed by the case 60 and the cover 70, which are welded together without any gaps. The movable switch 30 and the selector switch 40 are disposed inside this enclosed space 13. As a result, the case 60 and the cover 70 can protect the movable switch 30 and the selector switch 40. For example, the movable switch 30 and the selector switch 40 can be appropriately protected from dust and water that are likely to scatter around the power tool 100.

[0035] As shown in FIG. 3, the lower region of the case 60 that is not covered by the cover 70 is sealed with a resin mold 6. Therefore, the FET 52 and a portion of the capacitor 53 housed in the lower region of the case 60 are covered with the resin mold 6. This protects the FET 52 and the like from dust and water. The resin mold 6 is designed not to penetrate into the enclosed space 13. Therefore, the movable switch 30 and the selector switch 40 are less likely to have poor contact due to the resin mold 6. For ease of explanation, the resin mold 6 is not shown in figures other than FIG. 3. An adhesive 7 is applied to the upper end of the case 60 that is not covered by the cover. The upper end may be sealed with the resin mold 6.

[0036] The structure of the control module 10 will be described in detail below. As shown in FIG. 5, the case 60 of the control module 10 is a box-shaped member that extends vertically. The case 60 has a concave shape with one side open. The case 60 is positioned so that the opening faces rightward. The case 60 has a case bottom wall 61 that forms the bottom surface of the concave end, and a case peripheral wall 62 that rises upright from the periphery of the case bottom wall 61. The case peripheral wall 62 extends rightward. The case 60 has a rib 63 that protrudes in a generally rectangular shape from the case bottom wall 61 in its upper region. The rib 63 forms an auxiliary support that helps prevent the circuit board 50 from bending significantly.

[0037] The case peripheral wall 62 includes an upper case wall 62a, a lower case wall 62b, a front case wall 62c, and a rear case wall 62d. A welding protrusion 64 is formed on the case-facing surface 62e of the raised ends of the upper case wall 62a, the front case wall 62c, and the rear case wall 62d, which faces the cover 70 in the left-right direction. Each welding protrusion 64 is fused by ultrasonic welding. The case 60 has two case protrusions 65 that protrude inward in the front-to-rear direction at the vertical center of the front case wall 62c and the rear case wall 62d. As shown in FIGS. 1 and 2 , the case protrusions 65 prevent interference between the case 60 and the screws 2a and protrusions 2b of the grip 2. The screws 2a and protrusions 2b are inserted into the case protrusions 65. This allows the case 60 to be positioned relative to the grip 2.

[0038] As shown in FIG. 6, the cover 70 of the control module 10 is a substantially rectangular parallelepiped member. The cover 70 has a concave shape with one side open. The cover 70 is positioned so that the opening faces leftward. The cover 70 has a cover bottom wall 71 forming the bottom surface of the concave end and a cover peripheral wall 72 rising upright from the periphery of the cover bottom wall 71. The cover peripheral wall 72 extends leftward. The cover peripheral wall 72 has an upper cover wall 72a, a lower cover wall 72b, a front cover wall 72c, and a rear cover wall 72d. As shown in FIGS. 6 and 8, welding recesses 73 are formed on the upstanding ends of the upper cover wall 72a, the front cover wall 72c, and the rear cover wall 72d that laterally face the case-facing surface 62e. Each welding recess 73 corresponds to a welding protrusion 64 of the case 60. The cover 70 has guide pieces 74 that extend upward from the ends of the cover front wall 72c and the cover rear wall 72d. Each guide piece 74 extends toward the case 60 beyond the cover facing surface 72e.

[0039] As shown in FIGS. 5 and 6 , the circuit board 50 is a plate-like member extending in the vertical direction. The circuit board 50 is arranged with its surface facing in the horizontal direction. The circuit board 50 has two board recesses 50d recessed along the case protrusions 65 of the case 60. The surface 50a of the circuit board 50 is provided with contacts 56, 57, and 58 for the switches, a FET 52, a capacitor 53, a first lead wire 55a, a second lead wire 55b, and a third lead wire 55c. Six FETs 52 are provided on the surface 50a of the circuit board 50. The FETs 52 include a first FET 52a and a second FET 52b. The first FET 52a and the second FET 52b are arranged side by side in the front-to-back direction. The first FET 52a is elongated in the vertical direction. Three first FETs 52a are arranged side by side in the vertical direction. The second FET 52b is elongated in the front-to-back direction. The second FET 52b is provided at an angle of approximately 90 degrees relative to the first FET 52a along the circuit board 50. Three second FETs 52b are provided lined up in the vertical direction. A microcomputer 51 is provided on the back surface 50b of the circuit board 50. The microcomputer 51 is provided below the FETs 52. The capacitor 53 has a capacitance of 1000 μF, for example. The capacitance of the capacitor 53 may be in the range of 100 μF to 1200 μF, preferably 500 μF to 1200 μF, and more preferably 1000 μF to 1200 μF.

[0040] As shown in Figures 5 and 6, the first lead wire 55a is connected to the upper end of the circuit board 50. The first lead wire 55a is formed from five conductor wires. The first lead wire 55a is connected to the sensor board 4 (see Figure 2). The first lead wire 55a receives a detection signal from the sensor board 4. The second lead wire 55b is connected to the upper end of the circuit board 50. The second lead wire 55b is formed from two conductor wires. The second lead wire 55b is connected to the lighting fixture 5 (see Figure 2). The second lead wire 55b sends an operating current to the lighting fixture 5. The third lead wire 55c is connected to the center of the circuit board in the vertical direction. The third lead wire 55c is formed from three conductor wires. The third lead wire 55c is connected to the brushless motor 1c (see Figure 2). The third lead wire 55c is engaged with an engaging portion 76 formed on the outer peripheral surface of the cover 70.

[0041] As shown in FIG. 4, the circuit board 50 is housed inside the case 60. Each case protrusion 65 of the case 60 is inserted into each board recess 50d of the circuit board 50. This positions the circuit board 50 relative to the case 60. The back surface 50b (see FIG. 6) of the circuit board 50 abuts against a rib 63 (see FIG. 5) of the case 60. The circuit board 50 and the rib 63 are sealed together with an adhesive, without any gaps. While housed inside the case 60, the upper region of the circuit board 50 is covered by a cover 70. The FET 52 and the microcomputer 51 are arranged in an area outside the enclosed space 13. This allows efficient heat dissipation from the FET 52 and the microcomputer 51.

[0042] As shown in FIG. 7 , the cover 70 is placed over the case 60 so that the welding protrusions 64 of the case 60 are inserted into the welding recesses 73 of the cover 70. This causes the ends of the cover upper wall 72a and the case upper wall 62a to butt against each other, the ends of the cover front wall 72c and the case front wall 62c to butt against each other, and the ends of the cover rear wall 72d and the case rear wall 62d to butt against each other. Then, by ultrasonic welding, the fitted welding protrusions 64 and the welding recesses 73 are integrally welded together (adhesion portions 14). This causes the case-facing surface 62e and the cover-facing surface 72e to be welded together. That is, the case peripheral wall 62 and the base portions of the guide pieces 74 of the cover 70 are welded together. This allows the cover 70 to be integrally assembled to the case 60.

[0043] As a result of the above assembly, as shown in FIG. 4, the cover lower wall 72b protrudes into the inside of the case 60 along the case front wall 62c and the case rear wall 62d. The protruding end of the cover lower wall 72b abuts against the surface 50a of the circuit board 50. The cover lower wall 72b and the circuit board 50 are bonded to each other with an adhesive (sealing portion 77). This seals the cover lower wall 72b and the circuit board 50 together without any gaps. Therefore, when the lower region of the case 60 is sealed with the resin mold 6 (see FIG. 3), it is possible to prevent the resin mold 6 from entering the enclosed space 13 from the side of the cover lower wall 72b.

[0044] As shown in Fig. 7, the guide pieces 74 of the cover 70 are inserted into the gaps between the circuit board 50 and the case front wall 62c and the case rear wall 62d. This allows the cover 70 to be stably supported relative to the case 60 and the circuit board 50. As shown in Figs. 5 and 6, the side surface 50c of the circuit board 50 has recessed portions 50e that are recessed along the guide pieces 74. By inserting the guide pieces 74 into the recessed portions 50e, the guide pieces 74 can prevent the circuit board 50 from rattling in the up and down direction.

[0045] As shown in Figures 5 and 6, the cover 70 and the case 60 are assembled together to form a front through-hole 15 that penetrates in the front-to-rear direction. The front through-hole 15 opens in a circular shape, straddling the case front wall 62c and the cover front wall 72c. The cover 70 and the case 60 are assembled together to form an upper through-hole 16 that penetrates in the up-down direction. The upper through-hole 16 opens in a circular shape, straddling the case upper wall 62a and the cover upper wall 72a. As shown in Figure 8, the rod 21 extending from the trigger 20 is inserted into the front through-hole 15. The switching bracket 42 is inserted into the upper through-hole 16.

[0046] As shown in FIG. 8 , the trigger 20 has a rod 21 that extends through the front through-hole 15 into the cover 70, and a switch holder 22 that is provided at the tip of the rod 21. The rod 21 and switch holder 22 slide back and forth in response to the pulling operation of the trigger 20. Dust-proof grease 24 is provided between the rod 21 and the front through-hole 15. The grease 24 prevents dust and the like from entering the enclosed space 13 through the front through-hole 15. A seal such as an O-ring may be provided between the rod 21 and the front through-hole 15 together with the grease 24.

[0047] As shown in Figure 8, a spring 75 that urges the switch holder 22 forward is attached inside the cover 70. The trigger 20 is urged forward by the spring 75. The switch holder 22 is provided with a control brush 32 for the control switch 31 and a variable speed brush 34 for the variable speed switch 33. The control brush 32 and the variable speed brush 34 are arranged side by side in the vertical direction. Also provided inside the cover 70 are a movable metal plate 35a bent into a substantially L shape that constitutes the power switch 35, and a power contact 35e provided at the rear of the movable metal plate 35a and on the inner surface of the cover 70.

[0048] A switching holder 43 connected to the switching bracket 42 is provided inside the cover 70. The switching holder 43 can slide back and forth inside the cover 70. The switching holder 43 slides back and forth by the rotation of the switching bracket 42 accompanying the depression and movement of the switching button 41 (see FIG. 2). A switching brush 44 for the switching switch 40 is provided on the switching holder 43. The switching bracket 42 extends into the cover 70 through the upper through-hole 16. Dust-proof grease 46 is provided between the switching bracket 42 and the upper through-hole 16. The grease 46 can prevent dust and the like from entering the enclosed space 13 through the upper through-hole 16. A seal such as an O-ring may be provided between the switching bracket 42 and the upper through-hole 16 together with the grease 46.

[0049] As shown in FIG. 10, a control contact 56 for the control switch 31, a shift contact 57 for the shift switch 33, and a switching contact 58 for the selector switch 40 are provided on the upper surface 50a of the circuit board 50. The control contact 56 has a front control contact 56a and a rear control contact 56b. A gap 56c is formed between the front control contact 56a and the rear control contact 56b. The shift contact 57 has a front shift contact 57a and a rear shift contact 57b. A plurality of second slits 57c are formed in the front shift contact 57a. The switching contact 58 has a front switch contact 58a and a rear switch contact 58b. Two third slits 58c are formed in the front switch contact 58a.

[0050] 9 and 10, the power contacts 35e of the power switch 35 come into contact with each other, electrically connecting the battery 3, the control module 10, and the brushless motor 1c. The control contacts 56 of the control switch 31 are connected to each other via the control brushes 32, thereby starting the microcomputer 51. The microcomputer 51 then recognizes the pulling operation of the trigger 20 and turns on the lighting fixture 5. The speed change contacts 57 of the speed change switch 33 are connected to each other via the speed change brushes 34, thereby determining the magnitude of the voltage value input to the microcomputer 51.

[0051] As shown in FIGS. 8-10, in the initial state where the trigger 20 is not pulled, the power contacts 35e are not in contact with each other. In the initial state, the control contacts 56 are not connected to each other. In the initial state, the gearshift contacts 57 are connected to each other, and a relatively large voltage value is input to the microcomputer 51. When the trigger 20 is pulled, the power contacts 35e first come into contact with each other. Then, as the trigger 20 is pulled again, the control contacts 56 are connected to each other. As the trigger 20 is pulled again, the gearshift contacts 57 switch their connections so that the voltage value input to the microcomputer 51 gradually decreases. When the input voltage value falls below a predetermined value, the microcomputer 51 outputs an operation signal to the brushless motor 1c.

[0052] As shown in Figures 8 and 9, the movable metal plate 35a of the power switch 35 is supported so as to be rotatable in the vertical direction around the support metal plate 35c. The rear portion of the movable metal plate 35a is pulled downward by the tension spring 35d. That is, the movable metal plate 35a is biased in a direction in which the power contacts 35e contact each other. However, in the initial state, the switch holder 22 presses the locking portion 35b at the front of the movable metal plate 35a forward due to the resilience of the spring 75. This causes the rear portion of the movable metal plate 35a to rotate upward against the pulling force of the tension spring 35d. Therefore, the power contacts 35e are maintained in a state in which they do not contact each other. When the trigger 20 is pulled, the switch holder 22 moves rearward. This causes the rear portion of the movable metal plate 35a to rotate downward. As a result, the power contacts 35e contact each other. In this way, the power switch 35 is turned on. As a result, the battery 3, the control module 10, and the brushless motor 1c are electrically connected as described above.

[0053] As shown in Figures 8 and 9, when the cover 70 is placed over the circuit board 50, the control brush 32 of the control switch 31 is positioned to face the control contact 56. In the initial state, when the user does not pull the trigger, the front end of the control brush 32 contacts the front control contact 56a. The rear end of the control brush 32 contacts the board portion of the gap 56c between the control contact 56. In this state, the control contact 56 is not connected, and the control switch 31 is in the OFF state. This OFF state is maintained by the elastic force of the spring 75. When the user pulls the trigger 20, the switch holder 22 moves rearward, which in turn moves the control brush 32 rearward. As a result, the rear end of the control brush 32 contacts the rear control contact 56b. This connects the control contact 56, turning the control switch 31 on. The ON state of the control switch 31 activates the microcomputer 51. The microcomputer 51 recognizes the pulling of the trigger 20 and turns on the lighting fixture 5.

[0054] The shift brush 34 of the shift switch 33 is positioned to face the shift contact 57. In the initial state, when the user does not perform a pull operation, the front end of the shift brush 34 contacts the front portion of the front shift contact 57a. The rear end of the shift brush 34 contacts the rear shift contact 57b. In this initial connection state, a relatively large voltage value is input to the microcomputer 51. This initial connection state is maintained by the elastic force of the spring 75. When the user pulls the trigger 20, the switch holder 22 and the shift brush 34 move rearward. As a result, the front end of the shift brush 34 moves sequentially past each of the second slits 57c of the front shift contact 57a to the rear portion of the front shift contact 57a. The further rearward the front end of the shift brush 34 moves, the smaller the voltage value input to the microcomputer 51 becomes. When the voltage value falls below a predetermined value, the microcomputer 51 starts rotating the brushless motor 1c. The microcomputer 51 then operates to increase the rotation speed of the brushless motor 1c as the voltage value decreases. As a result, the rotation speed of the brushless motor 1c increases the harder the user pulls the trigger 20. The voltage value input to the microcomputer 51 may be controlled to be relatively small in the initial state and to increase as the front end of the variable speed brush 34 moves rearward. In this case, the microcomputer 51 may operate to rotate the brushless motor 1c when the input voltage value exceeds a predetermined value, and to operate so that the rotation speed increases as the voltage value increases.

[0055] The switching brush 44 of the selector switch 40 is positioned to face the switching contact 58. When the switching holder 43 is positioned in the front of the cover 70, the front end of the switching brush 44 contacts the front of the front switching contact 58a. The rear end of the switching brush 44 contacts the rear switching contact 58b. In this case, the microcomputer 51 determines that the selector switch 40 is in the forward rotation position. As a result, the microcomputer 51 transmits an operation signal to the brushless motor 1c to rotate it in the forward direction. When the switching holder 43 moves to the center of the cover 70, the front end of the switching brush 44 passes through the front third slit 58c and contacts the center of the front switching contact 58a. In this case, the microcomputer 51 determines that the selector switch 40 is in the neutral position. In this case, the microcomputer 51 does not transmit an operation signal to the brushless motor 1c even if the input voltage falls below a predetermined value. Therefore, the tool body 1 does not operate even when the user pulls the trigger 20. This prevents the tool body 1 from operating at a timing not intended by the user. When the switching holder 43 moves to the rear of the cover 70, the front end of the switching brush 44 passes over the rear third slit 58c and contacts the rear part of the front switching contact 58a. In this case, the microcomputer 51 determines that the selector switch 40 is in the reverse rotation position. As a result, the microcomputer 51 rotates the brushless motor 1c in the reverse direction when transmitting an operation signal to the brushless motor 1c.

[0056] As described above, as shown in FIG. 1, the control module 10 includes a box-shaped case 60 with one open side and a circuit board 50 housed in the case 60. As shown in FIG. 4, the circuit board 50 is equipped with a microcomputer 51 and a field effect transistor (FET) 52 used to control the brushless motor 1c of the power tool 100. A trigger 20 is movably coupled to the case 60. A movable switch 30, which is mechanically linked to the movement of the trigger 20, is connected to the circuit board 50. A cover 70 partially covers the opening of the case 60. The cover 70 covers a portion of the circuit board 50 and the movable switch 30. An adhesive portion 14 is provided to weld or bond the cover 70 and the case 60 together. The adhesive portion 14 forms an enclosed space 13 that encloses the movable switch 30.

[0057] The adhesive 14 melts at least a portion of the cover 70 and the case 60, welding them together. As a result, the gap between the cover 70 and the case 60 is filled by the adhesive 14. An enclosed space 13 is formed between the cover 70 and the case 60. The enclosed space 13 is more dustproof and waterproof than a closed space in which the cover 70 and the case 60 are connected to each other by, for example, a snap fit. The movable switch 30 is protected by the enclosed space 13. Thus, the movable switch 30 is less likely to experience poor contact continuity due to dust or water.

[0058] 4, the microcomputer 51 and the FET 52 are mounted on the circuit board 50 at positions that avoid the enclosed space 13. Therefore, when the microcomputer 51 and the FET 52 generate heat, the heat can be effectively dissipated from the microcomputer 51 and the FET 52.

[0059] 2, the operation and stop of the brushless motor 1c are switched by the movement of a movable switch 30 linked to a trigger 20. Therefore, the operation and stop of the brushless motor 1c are switched by operating the trigger 20.

[0060] As shown in FIG. 2, the movable switch 30 has a power switch 35 and a variable speed switch 33. The power switch 35 connects and disconnects the brushless motor 1c and the battery 3. The variable speed switch 33 controls the output of the brushless motor 1c depending on the amount of movement of the trigger 20. Therefore, by operating the trigger 20, the power switch 35 and the variable speed switch 33 are each variable. The movable switch 30 may have a control switch 31 that controls the operation of the microcomputer 51. The microcomputer 51 may, for example, recognize the input of the control switch 31 and turn on the lighting device 5 of the power tool 100. Therefore, the lighting device 5 can be reliably turned on by operating the trigger 20.

[0061] 7, the case 60 has a case bottom wall 61 and a case peripheral wall 62 extending in an upright manner from the peripheral edge of the case bottom wall 61. The cover 70 has a cover bottom wall 71 and a cover peripheral wall 72 extending in an upright manner from the peripheral edge of the cover bottom wall 71. The adhesive portion 14 welds or bonds the case-facing surface 62e of the case peripheral wall 62 and the cover-facing surface 72e of the cover peripheral wall 72, which face each other in the extending direction, to each other. Therefore, the opposing faces of the case peripheral wall 62 and the cover peripheral wall 72 are welded or bonded to each other.

[0062] 7, the cover 70 has guide pieces 74 that extend beyond the cover-facing surfaces 72e of the cover peripheral wall 72 toward the case 60 and pass between the case peripheral wall 62 and the side surface 50c of the circuit board 50. The guide pieces 74 fit between the circuit board 50 and the case peripheral wall 62. Therefore, the cover 70 is stably held relative to the circuit board 50 and the case 60 by the guide pieces 74. The adhesive portion 14 may be formed by welding or adhering the ends of the guide pieces 74 to the case 60.

[0063] As shown in Figures 3 and 4, a cover 70 is provided on one end side of the case 60. A cover bottom wall 72b located on the other end side of the cover peripheral wall 72 of the case 60 extends into the interior of the case 60. The extended cover bottom wall 72b of the cover 70 is bonded to the circuit board 50 by a seal portion 77. The other end side of the case 60 that is not covered by the cover 70 is covered by a resin mold 6. Therefore, the electronic components on the other end side of the case 60 are protected from dust and water by the resin mold 6. The resin mold 6 is prevented from entering the enclosed space 13 by the cover peripheral wall 72 and the seal portion 77. In this way, contact failure of the movable switch 30 due to the resin mold 6 can be suppressed.

[0064] As shown in Fig. 8, the operating member is a trigger 20 that is pulled. The trigger 20 has a rod 21 that passes between the case 60 and the cover 70, is connected to the movable switch 30 in the enclosed space 13, and moves in the axial direction. Therefore, when the case 60 and the cover 70 are assembled, the rod 21 is sandwiched between the case 60 and the cover 70. The rod 21 slides in the axial direction relative to the case 60 and the cover 70.

[0065] As shown in Figure 8, dust-proof grease 24 is provided between the rod 21 and the case 60, and between the rod 21 and the cover 70. This prevents dust from entering the cover 70. A changeover switch 40 that switches the rotation direction of the brushless motor 1c is also provided in the enclosed space 13. A changeover bracket 42 is connected to the changeover switch 40, passing between the case 60 and the cover 70. Dust-proof grease 46 is also provided between the changeover bracket 42 and the case 60, and between the changeover bracket 42 and the cover 70.

[0066] 8, there is provided a spring 75 that biases the operating member. The spring 75 is disposed in the enclosed space 13. Therefore, the enclosed space 13 prevents the spring 75 from being easily deformed by dust or water.

[0067] 4, movable switch 30 is disposed at one end of circuit board 50. Microcomputer 51 is mounted at the other end of circuit board 50 so as to be farther away from movable switch 30 than FET 52.

[0068] As shown in Fig. 1, the case 60 has a case protrusion 65 that protrudes toward the circuit board 50 so as to avoid the screw 2a provided in the main body of the power tool 100. As shown in Figs. 5 and 6, the circuit board 50 has a board recess 50d into which the case protrusion 65 is inserted. The circuit board 50 is positioned relative to the case 60 by the board recess 50d. Therefore, the case protrusion 65 of the case 60 serves both to avoid the screw 2a and to position the circuit board 50.

[0069] As shown in FIG. 4, a capacitor 53 that temporarily stores the voltage applied to the brushless motor 1c is provided on the circuit board 50. The capacitor 53 is disposed at a position outside the enclosed space 13. The capacitor 53 is a relatively large component. Therefore, it is possible to prevent the size of the cover 70 from increasing due to the capacitor 53. The capacitance of the capacitor 53 is, for example, 100 μF to 1200 μF. It is preferably 500 μF to 1200 μF, and more preferably 1000 μF to 1200 μF.

[0070] 3 and 4, the FET 52 is provided outside the cover 70 on the surface 50a of the circuit board 50 facing the opening of the case 60. The FET 52 is covered with the resin mold 6. Therefore, the FET 52 is located outside the cover 70, which facilitates heat dissipation. The FET 52 is also protected from dust and water by the resin mold 6.

[0071] 4 and 11, the FET 52 includes a first FET 52a and a second FET 52b that is inclined at an angle of 80 to 100 degrees relative to the first FET 52a along the circuit board 50. A heat sink 54 is provided to cover the first FET 52a and the second FET 52b. Therefore, the heat sink 54 can more efficiently dissipate heat from the first FET 52a and the second FET 52b.

[0072] As shown in FIG. 1 , the power tool 100 has a grip 2 extending from a tool body 1. A control module 10 is disposed within the grip 2. A cover 70 and a trigger 20 are disposed on one end of the control module 10. The grip 2 is relatively long and narrow, and the control module 10 is also relatively long. The cover 70 and the trigger 20 are disposed on one end of the control module 10. Therefore, the control module 10 has a component arrangement that corresponds to that of the grip 2.

[0073] 2, the power tool 100 includes a sensor board 4 on which a sensor 4a for detecting the rotation speed of the brushless motor 1c is mounted. A first lead wire 55a extends from the sensor board 4 to a position outside the enclosed space 13 of the circuit board 50. Therefore, one end of the first lead wire 55a can be easily mounted on the circuit board 50.

[0074] 2, the power tool 100 includes a lighting device 5. A second lead wire 55b extends from the lighting device 5 to a position outside the enclosed space 13 of the circuit board 50. Therefore, one end of the second lead wire 55b can be easily provided on the circuit board 50.

[0075] Various modifications can be made to the above-described embodiments. For example, a driver drill has been exemplified as the power tool. However, the control module of the present disclosure can also be similarly applied to an impact driver, impact wrench, chainsaw, hammer drill, reciprocating saw, grinder, polisher, portable band saw, circular saw, sliding circular saw, cutter, planer, earth auger drill, screwdriver, multi-tool (oscillating multi-tool or oscillating saw), etc. The battery can be used in common with each of the above-described types of power tools.

[0076] The control module may have two or more circuit boards. The operating member may have only a rod without a trigger. The operating member may be a paddle switch. The bonding portion may be ultrasonic welding or may be configured to bond the case and cover together using an adhesive. The operating member may be configured to move in the vertical direction.

[0077] The cover may be configured to be welded or adhered directly to a portion of the surface of the circuit board without being welded or adhered to the case. In this case, the case may be configured to house the circuit board, or may be configured to be welded or adhered to the back surface of the circuit board so as to cover a portion of the back surface of the circuit board. The control module may also be configured without a case. In this case, for example, the circuit board with the cover attached is housed in a temporary case, and the portion other than the enclosed space is covered with a resin mold. By then removing the case, the circuit board can be properly covered with the resin mold. By not having a case, the control module can be made smaller by the thickness of the case.

[0078] The case may be configured to open to the left. The cover may be configured to cover not only the upper region of the case, but also the lower region or the central region in the vertical direction. The cover may be configured such that only the ends of the front and rear walls of the cover are welded or glued to the ends of the peripheral wall of the case. In this case, the upper and lower walls of the cover may extend into the interior of the case and be glued to the circuit board by a seal. The welding protrusions are exemplified as being formed on the case. Alternatively, welding protrusions may be formed on the cover. Accordingly, welding recesses may be formed on the case.

[0079] The microcomputer may be mounted on the surface of the circuit board. The microcomputer may be mounted above the FETs. In the illustrated example, six FETs are mounted on the circuit board. Alternatively, any number of FETs, such as three or twelve, may be mounted as long as the number is a multiple of three. A heat sink may be attached to the FETs. For example, as shown in FIG. 11 , a heat sink 54 may be mounted on the circuit board 50 to cover the FETs 52. The heat sink 54 has a bottom plate 54a extending along the circuit board 50 and multiple fins 54b protruding rightward from the bottom plate 54a. Each fin 54b has a rectangular prism shape. The heat sink 54 is mounted so that its bottom plate 54a covers all of the FETs 52. The heat sink 54 is attached to the FETs 52 via an insulator such as an adhesive or a heat dissipation sheet. The heat sink 54 allows the FETs 52 to dissipate heat more efficiently. 12-14, the heat sink 54 may have fins of various different shapes, such as thin plate-like fins 54c and 54d, or fins 54e that protrude in the shape of a truncated quadrangular pyramid. [Explanation of symbols]

[0080] 100 Power tools 200 Tip tools 1 Tool body 1a Housing 1b Drive shaft 1c brushless motor 1d Drive mechanism 1e Reduction gear train 1g mode switching ring 1h Chuck 2 Grip 2a Screw 2b Protrusion 2c Battery mounting part 3 Battery 4 Sensor board 4a Sensor 5. Lighting equipment 6 Resin mold 10 Control module (control module for power tools) 11 Control section 12 Control Unit 13 Enclosed Space 14 Adhesive part 15 Front through hole 16 Upper through hole 20 Trigger (operating member) 21 Rod 22 Switch holder 24 Grease (dust-proof grease) 30 Movable Switch 31 Control Switch 32 Control Brush 33 Shift switch 34 variable speed brush 35 Power switch 35a Movable sheet metal 35b Locking part 35c support plate 35d tension spring 35e power contacts 40 Changeover switch 41 Switch button 42 Switching bracket 43 Switching holder 44 Switchable Brush 46 Grease (dust-proof grease) 50 Circuit Board 50a surface 50b back side 50c side 50d PCB recess 50e recess 51 Microcomputer 52 FET 52a First FET 52b Second FET 53 Capacitor 54 Heat sink 54a bottom plate 54b Fin 54c fins 54d Fin 54e fins 55 Lead wire 55a First lead wire 55b Second lead wire 55c 3rd lead wire 56 Control contact 56a Front control contact 56b Rear control contact 56c gap 57 Gear shift contacts 57a Front shift contact 57b Rear shift contact 57c Second slit 58 Changeover contact 58a Front switching contact 58b Rear switching contact 58c 3rd slit 60 cases 61 Case bottom wall 62 Case peripheral wall 62a Case top wall 62b Case bottom wall 62c Case front wall 62d Case back wall 62e Case facing surface 63 Ribs 64 Welded convex part 65 Case protrusion 70 Cover 71 Cover bottom wall 72 Cover peripheral wall 72a Cover upper wall 72b Cover bottom wall (wall section) 72c Cover front wall 72d Cover back wall 72e Cover facing surface 73 Welding recess 74 Guide piece 75 Spring 76 Locking part 77 Seal part

Claims

1. A control module for a power tool, A box-shaped case with one side open, a circuit board accommodated in the case; a microcomputer and a field effect transistor (FET) mounted on the circuit board and used to control a brushless motor of the power tool; an operating member movably connected to the case; a movable switch connected to the circuit board and mechanically linked to the movement of the operating member; a cover that is partially placed over the opening of the case, covering a portion of the circuit board and the movable switch; The control module for a power tool has an adhesive portion that forms an enclosed space that encloses the movable switch by welding or adhering the cover to the case.

2. 2. The power tool control module according to claim 1, The microcomputer and the FET are mounted on the circuit board at positions that avoid the enclosed space.

3. 3. The power tool control module according to claim 1, The brushless motor is configured to operate and stop in response to movement of the movable switch linked to the operating member.

4. 4. The power tool control module according to claim 3, The movable switch is a control module for a power tool that has a power switch that connects and disconnects the brushless motor and a battery, and a speed change switch that controls the output of the brushless motor depending on the amount of movement of the operating member.

5. 5. A control module for a power tool according to claim 1, The case has a case bottom wall and a case peripheral wall extending in an upright shape from a peripheral edge of the case bottom wall, The cover has a cover bottom wall and a cover peripheral wall extending in an upright shape from a peripheral edge of the cover bottom wall, The adhesive portion welds or bonds the case-facing surface of the case peripheral wall and the cover-facing surface of the cover peripheral wall, which face each other in the extending direction.

6. 6. The power tool control module according to claim 5, The cover has a guide piece that extends beyond the cover facing surface of the cover peripheral wall toward the case and passes between the case peripheral wall and the side of the circuit board, and the guide piece fits between the circuit board and the case peripheral wall.

7. 7. The power tool control module according to claim 6, The adhesive portion welds or adheres the extending end of the guide piece to the case.

8. The control module for a power tool according to any one of claims 5 to 7, The cover is provided on one end side of the case, a wall portion of the peripheral cover wall located on the other end side of the case extends into the inside of the case and is bonded to the circuit board by a seal portion; The other end of the case that is not covered by the cover is covered with a resin mold.

9. A control module for a power tool according to any one of claims 1 to 8, the operating member is a trigger that is pulled, The trigger has a rod that passes between the case and the cover and is connected to the movable switch in the enclosed space and moves axially.

10. 10. The power tool control module according to claim 9, A control module for a power tool, wherein dust-proof grease is provided between the rod and the case, and between the rod and the cover.

11. A control module for a power tool according to any one of claims 1 to 10, a spring that biases the operating member; The spring is disposed in the enclosed space.

12. A control module for a power tool according to any one of claims 1 to 11, The movable switch is disposed on one end side of the circuit board, The microcomputer is mounted on the other end of the circuit board so as to be farther from the movable switch than the FET.

13. A control module for a power tool according to any one of claims 1 to 12, the case has a case protrusion that protrudes toward the circuit board so as to avoid screws provided in the main body of the power tool; The circuit board is provided with a board recess into which the case protrusion is inserted, and the circuit board is positioned relative to the case by the board recess.

14. A control module for a power tool according to any one of claims 1 to 13, A capacitor for temporarily storing a voltage applied to the brushless motor is provided on the circuit board, and the capacitor is positioned away from the cover.

15. 15. The power tool control module of claim 14, The capacitor has a capacity of 20 μF to 50 μF.

16. A control module for a power tool according to any one of claims 1 to 15, The FET is provided outside the cover and on a surface of the circuit board facing the opening of the case, and the FET is covered with a resin mold.

17. A control module for a power tool according to any one of claims 1 to 16, the FET includes a first FET and a second FET provided at an angle of 80 to 100 degrees along the circuit board relative to the first FET, A control module for a power tool, wherein a heat sink is provided to cover the first FET and the second FET so as to straddle the first FET and the second FET.

18. A power tool including a control module according to any one of claims 1 to 17, A grip extending from the tool body, The control module is disposed within the grip; The power tool has the cover and the operating member disposed on one end side of the control module.

19. 19. The power tool according to claim 18, a sensor board provided with a sensor for detecting the rotation speed of the brushless motor; The power tool has a first lead wire extending from the sensor board to a position outside the enclosed space of the circuit board.

20. 20. The power tool according to claim 18 or 19, Lighting fixtures and The power tool has a second lead wire extending from the lighting fixture to a location outside the enclosed space of the circuit board.

Images