JP2016043454A - Electric tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit swinging of an electric tool.SOLUTION: An electronic pulse driver 1 includes: a hammer 20 rotationally driven by a brushless motor 10; an anvil 30 which holds a tip tool and is hit by the hammer 20; and a dynamic vibration absorber 60 which inhibits swinging in a rotary direction of the hammer 20. The dynamic vibration absorber 60 is disposed below a rotation center axis of the hammer 20.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an electric tool such as an electronic pulse driver, an impact driver, an impact wrench, and a driver drill.

  An impact tool, which is an example of an electric tool, includes a hammer that is rotationally driven by a drive source and an anvil that engages the hammer, and a tip tool such as a driver bit or a drill bit is held by the anvil (Patent Document 1). . In one aspect of the impact tool, when the load applied to the anvil is smaller than the predetermined load, the hammer and the anvil rotate together, and the tip tool held by the anvil rotates. At this time, only the rotational force is applied to the tip tool held by the anvil, and no striking force is applied. On the other hand, when the load applied to the anvil becomes larger than a predetermined load, the anvil is hit by the hammer. At this time, rotational force and impact force are applied to the tip tool held by the anvil. There are two types of impact tools: one that strikes the anvil while the hammer rotates in a certain direction (impact driver, impact wrench) and one that strikes the anvil by repeating the forward and reverse rotation (electronic pulse driver). .

JP 2008-307664 A

  In the hitting tool as described above, the hitting tool is swung in the rotating direction of the hammer by the hitting of the anvil by the hammer and the reaction thereof (the hitting tool swings left and right). In particular, when the output torque of the impact tool is increased in order to allow tightening of a large-diameter screw or bolt, the swing width of the impact tool increases, and stable work may become difficult. That is, in the case of the hitting tool as described above, the handle portion is swung left and right around the output shaft (drill bit).

  An object of the present invention is to prevent or reduce the swing of an electric power tool.

  The power tool of the present invention includes a main body, a hammer that is rotationally driven by a drive source accommodated in the main body, an anvil that holds a tip tool and is struck by the hammer, and the main body in the rotation direction of the hammer. A dynamic vibration absorber that suppresses swinging, and the dynamic vibration absorber is disposed below the rotation center axis of the hammer.

  In one aspect of the present invention, a trigger switch for operating the drive source is provided, and the dynamic vibration absorber is disposed below the trigger switch.

  In another aspect of the present invention, an electric motor as the drive source and a battery mounting portion to which a battery as a power source of the electric motor is mounted are provided, and the dynamic vibration absorber includes the trigger switch and the battery. It arrange | positions between mounting parts.

  In another aspect of the present invention, the main body includes a trunk portion that accommodates the drive source, the hammer, and the anvil, and a handle portion that extends from the trunk portion and is gripped by an operator. The trigger switch is disposed at an upper portion of the handle portion, and the battery mounting portion is disposed at a lower portion of the handle portion.

  In another aspect of the present invention, the dynamic vibration absorber attenuates sliding of the mass body, a support shaft orthogonal to the rotation center axis of the hammer, a mass body that can slide on the support shaft, and the like. A damping member.

  In another aspect of the present invention, the first damping member is disposed between one end of the support shaft and one end of the mass body, and is disposed between the other end of the support shaft and the other end of the mass body. A second damping member is provided.

  In another aspect of the present invention, each of the first damping member and the second damping member includes two or more types of springs having different spring constants.

  In another aspect of the present invention, the mass body is provided with fins, and the fins move together with the mass body to generate cooling air.

  In another aspect of the present invention, a circuit board is disposed in the vicinity of the mass body and at a position where the cooling air can reach.

  In another aspect of the present invention, the power tool includes a main body including a body portion that houses a drive source and a handle portion that extends downward from the body portion and is gripped by an operator, and is positioned in front of the main body, And a dynamic vibration absorber that suppresses the swinging of the handle portion in the left-right direction around the output portion.

  In another aspect of the present invention, an electric tool includes an output unit that holds a tip tool, a body unit that houses a drive source that drives the output unit, and a handle unit that extends from the body unit and is gripped by an operator. A main body and a dynamic vibration absorber that suppresses swinging of the handle portion in a rotation direction of the output portion with the output portion as a center.

  In another aspect of the present invention, the dynamic vibration absorber is disposed on an end side opposite to the body portion in the handle portion.

  According to the present invention, the swing of the power tool is prevented or reduced.

1 is an external perspective view of an electronic pulse driver according to a first embodiment. It is a longitudinal cross-sectional view of the electronic pulse driver shown by FIG. It is a partial expanded sectional view of the electronic pulse driver shown by FIG. It is sectional drawing along the AA line shown by FIG. It is a partial expanded sectional view which shows the 1st modification of the electronic pulse driver which concerns on 1st Embodiment. It is sectional drawing along the BB line shown by FIG. It is a partial expanded sectional view which shows the 2nd modification of the electronic pulse driver which concerns on 1st Embodiment.

(First embodiment)
Hereinafter, an example of an embodiment of the electric power tool of the present invention will be described in detail. The electric power tool according to the present embodiment is an impact tool, and more specifically, an electronic pulse driver mainly used for screw tightening work or bolt tightening work.

  As shown in FIG. 1, the electronic pulse driver 1 (main body) according to this embodiment has a housing 4 including a body portion 2 and a handle portion 3. The handle portion 3 is a portion that is gripped by an operator who uses the electronic pulsed driver 1, and extends in a direction intersecting the trunk portion 2 from a substantially longitudinal center of the trunk portion 2. In other words, the housing 4 has the handle portion 3 and the body portion 2 provided on one end side of the handle portion 3, and has a substantially T-shaped side shape as a whole. In the following description, the longitudinal direction of the handle portion 3 is defined as “vertical direction”. Furthermore, the side on which the body portion 2 is provided is defined as “upward”, and the opposite side is defined as “downward”. That is, the handle portion 3 extends downward from the body portion 2. Further, the longitudinal direction of the body portion 2 is defined as “front-rear direction”, and the direction orthogonal to both the up-down direction and the front-rear direction is defined as “left-right direction”.

  The housing 4 is composed of two substantially symmetric half-shell members, and these two half-shell members are fixed to each other by screws (not shown). Therefore, a plurality of screw bosses 5 (FIG. 2) are formed in one half-cracked member, and a plurality of screw holes into which screws to be screwed into the screw bosses 5 are inserted in the other half-cracked member. Is formed.

  As shown in FIG. 2, the body portion 2 of the housing 4 accommodates an electric motor 10 as a drive source, a hammer 20 that is rotationally driven by the electric motor 10, and an anvil 30 that engages the hammer 20. The electric motor 10 in the present embodiment is a brushless DC motor, and in the following description, the electric motor 10 is referred to as “brushless motor 10”.

  The brushless motor 10 includes a rotor 11, a stator 12, and an output shaft 13 extending in the front-rear direction. The output shaft 13 passes through the rotor 11, one end side of the output shaft 13 is rotatably supported by the rear bearing 14, and the other end side of the output shaft 13 is rotatably supported by the front bearing 15.

  A circuit board (inverter circuit board 16) on which a plurality of switching elements 16a are mounted is disposed between the rear bearing 14 and the brushless motor 10, and the brushless motor 10 is inverter-controlled by these switching elements 16a. The inverter circuit board 16 is also equipped with a hall element for detecting the rotational position of the rotor 11.

  A cooling fan 17 is provided between the front bearing 15 and the brushless motor 10. The cooling fan 17 is mounted on the output shaft 13 of the brushless motor 10 and rotates together with the output shaft 13. The cooling fan 17 is a centrifugal fan, and when the cooling fan 17 rotates, outside air (air) is taken into the housing 4 from the suction port 18 (FIG. 1) formed at the rear and side surfaces of the body portion 2. The air taken into the housing 4 mainly passes between the rotor 11 and the stator 12 and is sucked into the cooling fan 17 and sent out radially outward. The air sent from the cooling fan 17 is exhausted to the outside through an exhaust port 19 (FIG. 1) formed on the side surface of the body part 2.

  A trigger switch 40 for operating / stopping the brushless motor 10 is provided above the handle portion 3, and a forward / reverse switching switch 41 is provided above the trigger switch 40. On the other hand, a battery mounting portion 42 to which a battery 100 as a power source of the brushless motor 10 is mounted is provided below the handle portion 3. Specifically, a locking projection that can be fitted into a locking groove formed on the upper end surface of the battery 100 is formed on the lower end surface of the handle portion 3. A power supply terminal is provided on the lower end surface of the handle portion 3. When the engaging protrusion formed on the lower end surface of the handle portion is fitted into the engaging groove formed on the upper end surface of the battery, the battery 100 is attached to the lower end of the handle portion 3 and the power supply terminal provided in the battery 100 is They contact the power terminal and are electrically connected. There is also an embodiment in which a locking groove is formed on the lower end surface of the handle portion and a locking projection is formed on the upper end surface of the battery. There is also an embodiment in which a locking groove and a locking projection are formed on both the lower end surface of the handle part and the upper end surface of the battery.

  Further, a circuit board (control circuit board 43) on which a control circuit for controlling the rotation speed of the brushless motor 10 and the like according to the operation of the trigger switch 40 is mounted is built in the lower part of the handle part 3. A dial switch 44 for switching the operation mode of the electronic pulse driver 1 is disposed above the control circuit board 43.

  When the trigger switch 40 is operated (pulled), electric power is supplied to the brushless motor 10 according to control by the control circuit mounted on the control circuit board 43, and the brushless motor 10 operates.

  In addition, the battery 100 in this embodiment is a battery pack in which a plurality of lithium ion batteries are accommodated. But the battery accommodated in a battery pack is not restricted to a lithium ion battery, For example, a nickel hydride battery and other secondary batteries may be sufficient. The electronic pulse driver 1 according to the present embodiment has three operation modes of “drill mode (without clutch)”, “drill mode (with clutch)”, and “impact mode”, and these operation modes are dialed. It is switched by operating the switch 44.

  The structure inside the body part 2 will be described again. A reduction mechanism 50 including two planetary gear mechanisms (a first planetary gear mechanism and a second planetary gear mechanism) is provided between the front bearing 15 and the hammer 20, and a brushless motor is provided via the reduction mechanism 50. The ten output shafts 13 and the hammer 20 are coupled so as to be able to transmit power. The rotation of the output shaft 13 is decelerated in two stages by the decelerating mechanism 50 and transmitted to the hammer 20. That is, the hammer 20 is rotationally driven by the brushless motor 10. Further, the rotation center axis of the hammer 20 coincides with the axis of the output shaft 13 of the brushless motor 10.

  An anvil 30 serving as an output unit that engages with the hammer 20 and holds a tip tool (not shown) (for example, a driver bit) is disposed in front of the hammer 20 that is rotationally driven as described above. . The anvil 30 includes an anvil claw 31 that overlaps the hammer 20 in the rotation direction, and a mounting hole 32 into which one end of a not-shown tip tool (for example, a driver bit) is inserted. The mounting hole 32 has a polygonal cross-sectional shape, and when one end of the tip tool is inserted into the mounting hole 32, the anvil 30 and the tip tool are connected so as not to rotate relative to each other.

  The hammer 20 and the anvil 30 are accommodated in a metal hammer case 33 and are rotatably supported. Therefore, when the hammer 20 is rotationally driven, the rotational force and / or the striking force is transmitted to the anvil 30 and the tip tool held by the anvil 30. Specifically, when the reaction force received by the anvil 30 via the tip tool is smaller than a predetermined magnitude, the brushless motor 10 continuously rotates in the same direction, and the hammer 20 and the anvil 30 also continuously rotate at the same speed in the same direction. To do. At this time, only the rotational force is transmitted to the tip tool, and the striking force is not transmitted. On the other hand, when the reaction force received by the anvil 30 via the tip tool becomes larger than a predetermined magnitude, the rotation direction of the brushless motor 10 is alternately switched between the normal rotation direction and the reverse rotation direction before the brushless motor 10 is locked. . Therefore, the hammer 20 repeats forward rotation and reverse rotation alternately. As a result, the anvil 30 is hit by the hammer 20, and the rotational force and the hitting force are transmitted to the tip tool held by the anvil 30. The drive control of the brushless motor 10 as described above based on the reaction force received by the anvil 30 is realized by the cooperation of the switching element mounted on the inverter circuit board 16 and the control circuit mounted on the control circuit board 43. Is done. The reaction force received by the anvil 30 is detected based on the output torque of the brushless motor 10. Specifically, as the reaction force received by the anvil 30 increases, the output torque of the brushless motor 10 also increases. Therefore, when the output torque exceeds a predetermined threshold, it is determined that the reaction force received by the anvil 30 has become larger than a predetermined magnitude, and the drive mode of the brushless motor 10 is switched.

  As shown in FIG. 3, a dynamic vibration absorber 60 that suppresses swinging of the hammer 20 (FIG. 2) in the rotation direction is built in the lower portion of the handle portion 3. Specifically, a dynamic vibration absorber 60 is provided in the vicinity of the control circuit board 43.

  As shown in FIG. 4, the dynamic vibration absorber 60 includes a support shaft 61 that extends in the left-right direction, a mass body 62 that can slide on the support shaft 61, a damping member that attenuates the sliding of the mass body 62, and It is composed of The support shaft 61 extending in the left-right direction is orthogonal to the axis of the output shaft 13 (FIG. 2) extending in the front-rear direction, and is also orthogonal to the rotation center axis of the hammer 20 (FIG. 2).

  The mass body 62 shown in FIG. 4 is a lump of metal (for example, iron or lead) formed in a cylindrical shape, and a through hole is formed at the center thereof. The support shaft 61 is inserted into the through hole of the mass body 62 and penetrates the mass body 62, and the mass body 62 can slide on the support shaft 61.

  One end side of the support shaft 61 protruding from one end face (right end face 62a) of the mass body 62 penetrates the inside of the spring 63a as the first damping member, and the other end face (left end face of the mass body 62). The other end side of the support shaft 61 protruding from 62b) penetrates the inside of the spring 63b as the second damping member. Further, one end of the support shaft 61 protruding from the spring 63 a is fixed to one half-cracked member of the housing 4, and the other end of the support shaft 61 protruding from the spring 63 b is connected to the other half-cracked member of the housing 4. It is fixed. Specifically, one end of the support shaft 61 is fixed to a support plate 64a provided on one half-crack member, and the other end of the support shaft 61 is a support plate 64b provided on the other half-crack member. It is fixed to. That is, the support shaft 61 passes through the mass body 62 and crosses the lower portion of the handle portion 3, and the mass body 62 and the two springs 63 a and 63 b are disposed on the support shaft 61. Further, the spring 63 a is disposed between one end of the support shaft 61 and one end of the mass body 62, and the spring 63 b is disposed between the other end of the support shaft 61 and the other end of the mass body 62. . In other words, the mass body 62 is sandwiched between the two springs 63a and 63b.

  When the anvil 30 is hit by the hammer 20 shown in FIG. 2, the hammer 20 swings in the rotational direction. Specifically, the electronic pulse driver 1 (main body) is swung from side to side with the rotation center axis of the hammer 20 as a fulcrum. That is, the electronic pulse driver 1 is swung in the direction of arrows ab in FIG. At this time, since the heavy battery 100 is attached to the lower end of the handle portion 3 farthest from the rotation center axis (swing fulcrum) of the hammer 20 (FIG. 2), the swing of the handle portion 3 is promoted. At the same time, the portion closer to the lower end of the handle portion 3 has a larger swing width.

  The dynamic vibration absorber 60 shown in FIG. 4 suppresses (prevents or reduces) the swing. Specifically, when the handle portion 3 swings as described above, the mass body 62 moves relatively in the direction opposite to the swing direction of the handle portion 3, and the electronic pulse driver 1 including the handle portion 3 swings. Prevented or reduced. More specifically, when the handle portion 3 swings in the right direction, the mass body 62 moves (slides) on the support shaft 61 in the left direction while compressing the spring 63b. On the other hand, when the handle portion 3 swings leftward, the mass body 62 moves (slids) rightward on the support shaft 61 while compressing the spring 63a.

  Further, the mass body 62 moved leftward on the support shaft 61 is pushed back rightward by the restoring force of the compressed spring 63b. On the other hand, the mass body 62 moved rightward on the support shaft 61 is pushed back leftward by the restoring force of the compressed spring 63a. That is, the two springs 63 a and 63 b act so as to position the mass body 62 at the center of the support shaft 61. In other words, the two springs 63a and 63b attenuate the sliding of the mass body 62 that accompanies the swing of the handle portion 3, and the swing of the electronic pulse driver 1 including the handle portion 3 is effectively reduced or suppressed. The

(First modification)
As shown in FIGS. 5 and 6, fins 65 can be provided on the mass body 62 of the dynamic vibration absorber 60. The fin 65 is integrated with the mass body 62, and moves together with the mass body 62 when the mass body 62 slides (moves) as the handle portion 3 swings. When the fins 65 are moved, wind (cooling air) is generated, and the control circuit board 43 disposed in the vicinity of the mass body 62 is cooled.

  However, the positional relationship between the mass body 62 (fin 65) and the control circuit board 43 is not limited to the illustrated positional relationship. The mass body 62 (fin 65) and the control circuit board 43 may be disposed at a position where the cooling air generated by the movement of the fin 65 can reach the control circuit board 43. Further, the number and shape of the fins 65 are not limited to the illustrated number and shape, and can be arbitrarily changed. Furthermore, the mass body 62 and the fin 65 may be integrally formed.

(Second modification)
As shown in FIG. 7, the spring 66a may be disposed between the spring 63a and the support plate 64a, and the spring 66b may be disposed between the spring 63b and the support plate 64b.

  Here, the spring constants of the spring 63a and the spring 63b are the same, and the spring constants of the spring 66a and the spring 66b are the same. However, the spring constants of the adjacent springs 63a and 66a are different from each other, and the spring constants of the adjacent springs 63b and 66b are different from each other. Specifically, the spring constant of the spring 63a is smaller than the spring constant of the spring 66a, and the spring constant of the spring 63b is smaller than the spring constant of the spring 66b.

  That is, two types of springs 63a and 66a having different spring constants are disposed between the right end surface 62a of the mass body 62 and the support plate 64a. Further, two types of springs 63b and 66b having different spring constants are disposed between the left end surface 62b of the mass body 62 and the support plate 64b. In this modification, the springs 63a and 66a correspond to the first damping member, and the springs 63b and 66b correspond to the second damping member. In other words, the first damping member in this modification includes two types of springs (springs 63a and 66a) having different spring constants, and the second damping member has two types of springs (springs 63b) having different spring constants. , 66b). Thus, by using two or more types of springs having different spring constants in combination, it is possible to effectively prevent or reduce swinging at different speeds. That is, the range of oscillation that can be suppressed is expanded.

  Of course, the first damping member and the second damping member may include three or more types of springs. In addition, the first damping member and the second damping member can be configured by rubber, an oil damper, or the like.

  The present invention is not limited to the above-described embodiments and modifications, and various modifications can be made without departing from the scope of the invention. For example, the electric power tool of the present invention includes an impact driver and an impact wrench. Also included is an electric tool such as a driver drill that does not have a striking mechanism and transmits the rotation of the electric motor to the output shaft via a speed reduction mechanism. That is, it is the essence of the present invention to suppress the swing of the main body in the rotation direction of the output shaft. The drive source of the electric tool of the present invention is not limited to a brushless motor, and is not limited to an electric motor. The operation mode of the impact tool and the control mode of the drive source mentioned in the above embodiment are examples.

DESCRIPTION OF SYMBOLS 1 Electronic pulse driver 2 Body part 3 Handle part 4 Housing 5 Screw boss 10 Electric motor (brushless motor)
DESCRIPTION OF SYMBOLS 11 Rotor 12 Stator 13 Output shaft 14 Back bearing 15 Front bearing 16 Inverter circuit board 16a Switching element 17 Cooling fan 18 Suction port 19 Exhaust port 20 Hammer 30 Anvil 31 Anvil claw 32 Mounting hole 33 Hammer case 40 Trigger switch 41 Forward / reverse rotation Changeover switch 42 Battery mounting part 43 Control circuit board 44 Dial switch 50 Deceleration mechanism 60 Dynamic vibration absorber 61 Support shaft 62 Mass body 62a Right end face 62b Left end face 63a, 63b, 66a, 66b Spring 64a, 64b Support plate 65 Fin 100 Battery

Claims (12)

The body,
A hammer rotated by a drive source housed in the main body;
An anvil that holds the tip tool and is struck by the hammer;
A dynamic vibration absorber that suppresses swinging of the main body in the rotation direction of the hammer,
The dynamic vibration absorber is disposed below the rotation center axis of the hammer,
Electric tool. A trigger switch for operating the drive source;
The dynamic vibration absorber is disposed below the trigger switch,
The power tool according to claim 1. An electric motor as the drive source;
A battery mounting portion to which a battery as a power source of the electric motor is mounted;
The dynamic vibration absorber is disposed between the trigger switch and the battery mounting portion.
The electric tool according to claim 2. The body is
A body portion for housing the drive source, the hammer and the anvil;
A handle portion extending from the body portion and gripped by an operator,
The trigger switch is disposed at an upper portion of the handle portion, and the battery mounting portion is disposed at a lower portion of the handle portion;
The power tool according to claim 3. The dynamic vibration absorber is
A support shaft orthogonal to the rotation center axis of the hammer;
A mass body slidable on the support shaft;
A damping member for damping the sliding of the mass body,
The electric tool according to any one of claims 1 to 4. A first damping member disposed between one end of the support shaft and one end of the mass body;
A second damping member disposed between the other end of the support shaft and the other end of the mass body,
The power tool according to claim 5. Each of the first damping member and the second damping member includes two or more types of springs having different spring constants.
The power tool according to claim 6. Having fins provided on the mass body;
The fin moves together with the mass body to generate cooling air,
The power tool according to claim 5.   The electric tool according to claim 8, wherein a circuit board is disposed in a vicinity of the mass body and at a position where the cooling air can reach. A main body including a body portion that houses a drive source, and a handle portion that extends downward from the body portion and is gripped by an operator;
An output unit positioned in front of the main body and holding a tip tool;
A dynamic vibration absorber that suppresses swinging of the handle portion in the left-right direction around the output portion,
Electric tool. An output section for holding the tip tool;
A main body including a body part that houses a drive source that drives the output part, and a handle part that extends from the body part and is gripped by an operator;
A dynamic vibration absorber that suppresses swinging of the handle portion in the rotation direction of the output portion around the output portion,
Electric tool. The dynamic vibration absorber is disposed on the end side opposite to the body portion in the handle portion,
The power tool according to claim 10 or 11.

Images