JP2008062340A - Power tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power tool capable of compactly storing a switching lever by reducing the width dimension of the switching lever, and capable of wiring lead wire at the opposite trigger side of the switching lever. <P>SOLUTION: An impact driver (power tool) 1 is equipped with a motor 4, a planetary gear mechanism (speed reducing mechanism part) 5, and a hammering mechanism part which converts a rotation of the motor 4 speed-reduced by the planetary gear mechanism 5 to a rotary hammering force and transmits the force to the tip end tool. The impact driver varies the rotating speed of the motor 4 according to the stroke of a trigger, wherein the maximum stroke of the trigger can be switched in two stages by selectively moving the switching lever 8 to a first position of the high-speed side and a second position of the low-speed side, and is provided with a click part 8a for giving a click feeling to the movement of the first and second position of the switching lever 8. The click part 8a is provided on the trigger side, and the end surface of the opposite rigger side of the switching lever 8 is made to be a flat surface. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electric power tool such as an impact driver capable of switching a maximum rotation speed of a motor as a driving source in two stages by a switching lever.

  An electric power tool such as an impact driver converts a motor that is a drive source, a speed reduction mechanism that decelerates rotation of the motor, and rotation of the motor decelerated by the speed reduction mechanism into a rotational impact force and transmits it to the tip tool. The rotation mechanism of the motor can be varied according to the stroke of the trigger.

  By the way, in the case of impact drivers, etc., in order to prevent problems such as cutting of the screw head and excessive screwing, the maximum stroke of the trigger is regulated according to the size of the screw, the material of the material to be tightened, the finish level, etc. A switching lever is provided for suppressing the maximum rotation speed (output) below a certain value (see, for example, Patent Document 1).

As shown in FIG. 7, the switching lever 108 includes a switching member 108A that appears and disappears in a movement path of a trigger (not shown) and switches the maximum stroke of the trigger in two stages, and an operation unit 108B that supports the switching member 108A. The maximum stroke of the trigger is switched in two steps by operating the operation unit 108B and selectively moving to the first position on the high speed side and the second position on the low speed side. Here, the operating portion 108B of the switching lever 108 is provided with a moderation portion 108a on the counter-trigger side (left side in FIG. 7) that gives a moderation feeling to the movement of the switching lever 108 to the first and second positions. It has been. The moderation portion 108a is configured by forming an engagement protrusion 108a-2 in the middle of the vertically long portion 108a-1 that can be bent and deformed by forming a slit 108b in the operation portion 108B. 108a-2 selectively engages with two engaging grooves (not shown) formed on the housing side, thereby giving a sense of moderation to the movement of the switching lever 108.
Japanese Utility Model Publication No. 51-072769

  However, in the conventional switching lever 108 shown in FIG. 7, the moderation portion 108a is provided on the counter-trigger side (the left side in FIG. 7). In addition, since the engaging protrusion 108a-2 of the moderation portion 108a protrudes, there is a problem that a lead wire cannot be wired on the counter-trigger side of the switching lever 108.

  The present invention has been made in view of the above problems. The object of the present invention is to reduce the width dimension of the switching lever so that the switching lever can be stored compactly, and the lead is provided on the counter-trigger side of the switching lever. An object of the present invention is to provide a power tool capable of wiring.

  In order to achieve the above object, the present invention provides a motor that is a drive source, a speed reduction mechanism that decelerates the rotation of the motor, and converts the rotation of the motor that has been decelerated by the speed reduction mechanism into a rotational impact force. An impact mechanism for transmitting to the tool is provided, the rotational speed of the motor is varied according to the trigger stroke, and the switching lever is selectively moved to the first position on the high speed side and the second position on the low speed side. In the electric tool comprising a moderation portion capable of switching the maximum stroke of the trigger in two stages and imparting a moderation feeling to the movement of the switching lever to the first and second positions. Is provided on the trigger side, and the end surface on the counter-trigger side of the switching lever is a flat surface.

  According to the present invention, since the moderation portion of the switching lever is provided on the trigger side, the width dimension of the switching lever is reduced, the installation space is also reduced, and the switching lever can be stored compactly.

  Further, as a result of providing the moderation portion of the switching lever on the trigger side, the end surface on the counter-trigger side of the switching lever can be made a flat surface, and a wiring space can be secured outside the flat end surface. Lead wires can be wired in the space.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a left side view of an impact driver as an embodiment of an electric power tool according to the present invention, FIG. 2 is a right sectional view showing an internal structure of the impact driver, and FIG. 3 is a switch lever of the impact driver to a high speed side. 4 is a right sectional view showing a state where the switching lever of the impact driver is switched to the low speed side, FIG. 5 is a perspective view of the switching lever, and FIG. 6 is a front view of the switching lever. .

  First, the basic configuration and operation of the impact driver 1 according to the present invention will be described with reference to FIGS. 1 and 2. The illustrated impact driver 1 has a housing 2 and a hammer case 3 which are outer frames forming an outer shape. The housing 2 includes a substantially cylindrical body portion 2A extending in the front-rear direction, and a handle portion 2B connected to the body portion 2A so as to form a substantially T shape in a side view. In the body 2A of the housing 2, a motor 4 as a drive source and a planetary gear mechanism 5 as a speed reduction mechanism for decelerating the rotation of the motor 4 are accommodated as shown in FIG. The hammer case 3 accommodates an impact mechanism that converts the rotation of the motor 4 decelerated by the planetary gear mechanism 5 into a rotational impact force and transmits it to a tip tool (not shown). Details of the striking mechanism will be described later.

  In addition, a switch 7 having a trigger 6 at the top is provided inside the handle portion 2B of the housing 2, and a switching lever 8 is provided below the switch 7. Further, a battery receiving portion 9 is accommodated in the lower portion inside the handle portion 2B, and a battery 10 as a rechargeable power source is detachably attached to the lower end of the handle portion 2B. Here, power supply from the battery 10 to the motor 4 is performed from the two lead wires 11 through the switch 7 and the FET 12.

  By the way, the trigger 6 pulls the trigger to start the motor 4, but the rotation speed of the motor 4 is varied according to the stroke (pull amount) of the trigger 6. Specifically, the rotational speed of the motor 4 increases in proportion to the increase of the stroke of the trigger 6, but the maximum stroke (maximum pulling amount) of the trigger 4 is switched in two stages by the switching lever 8. The maximum rotation speed (maximum output) of 4 is switched between two stages. Details of the switching lever 8 will be described later.

  Thus, in such an impact driver 1, when the operator activates the trigger 6 to start the motor 4, the rotation of the output shaft (motor shaft) 4a of the motor 4 is decelerated by the planetary gear mechanism 5. It is transmitted to the spindle 13 and the spindle 13 is rotationally driven at a predetermined speed. Here, the spindle 13 and the hammer 14 are connected by a cam mechanism, and this cam mechanism is formed on the V-shaped spindle cam groove 13 a formed on the outer peripheral surface of the spindle 13 and the inner peripheral surface of the hammer 14. Further, it is composed of a V-shaped hammer cam groove 14a and a ball 15 which engages with these cam grooves 13a, 14a.

  Further, the hammer 14 is always urged by the spring 16 in the tip direction (to the right in FIG. 2), and when stationary, the ball 15 and the cam grooves 13a and 14a are engaged with each other to separate the gap from the end surface of the anvil 17. In the position. And the convex part is each formed in two places on the rotation plane where the hammer 14 and the anvil 17 oppose each other symmetrically. A tip tool (not shown) is detachably attached to the anvil 17.

  By the way, when the spindle 13 is rotationally driven at a predetermined speed as described above, the rotation of the spindle 13 is transmitted to the hammer 14 via the cam mechanism, and the hammer 14 is not rotated halfway before the hammer 14 is rotated halfway. 14 is engaged with the projection of the anvil 17 and the anvil 17 is rotated. When the relative reaction force is generated between the hammer 14 and the spring 16 by the reaction force at that time, the hammer 14 is Then, the spring 16 starts to retract toward the motor 4 side while compressing the spring 16 along the spindle cam groove 13a of the cam mechanism.

  When the protrusion of the hammer 14 moves over the protrusion of the anvil 17 due to the backward movement of the hammer 14 and the engagement between the two is released, the hammer 14 accumulates in the spring 16 in addition to the rotational force of the spindle 13. While being accelerated rapidly in the rotational direction and forward by the action of the elastic energy and the cam mechanism, the spring 16 is moved forward by the biasing force of the spring 16, and the convex portion is reengaged with the convex portion of the anvil 17 to be integrated. Begin to rotate. At this time, since a strong rotational impact force is applied to the anvil 17, the rotational impact force is transmitted to a screw (not shown) via a tip tool attached to the anvil 17.

  Thereafter, the same operation is repeated, and the rotational impact force is intermittently and repeatedly transmitted from the tip tool to the screw, and the screw is screwed into a material to be fastened such as wood.

  Next, details of the switching lever 8 will be described with reference to FIGS.

  As described above, the switching lever 8 switches the maximum rotation speed (maximum output) of the motor 4 to two stages by switching the maximum stroke (maximum pulling amount) of the trigger 6 to two stages. As shown in FIG. 6, an L-shaped switching member 8A for appearing in the movement path of the trigger 6 (see FIGS. 3 and 4) to switch the maximum stroke of the trigger 6 in two stages, and the switching member 8A A flat plate-shaped operation portion 8B to be supported and an elliptical operation element 8C exposed on the surface of the handle portion 2B of the housing 2 are provided.

  Thus, as shown in FIGS. 3 and 4, the switching lever 8 has a switching member 8A and an operation portion 8B housed in the handle portion 2B of the housing 2, and the operation portion 8B is connected to the handle portion 2B. The rib-shaped guide portions 2a and 2b erected in parallel on the inner surface in the vertical direction are fitted and held so as to be movable up and down. Therefore, the switching lever 8 is movable up and down, and is a first position on the high speed side ("P" position shown in FIG. 1) and a second position on the low speed side ("S" position shown in FIG. 1). The maximum stroke of the trigger 6, that is, the maximum rotation speed (maximum output) of the motor 4 is switched in two steps.

  By the way, as shown in FIGS. 5 and 6, the switch lever 8 is moved to the first and second positions on the trigger 6 side (right side of FIGS. 5 and 6) of the operation portion 8 </ b> B of the switch lever 8. A moderation portion 8a for imparting a moderation feeling is provided. The moderation portion 8a is configured by forming an engagement protrusion 8a-2 in the middle of the vertically long portion 8a-1 that can be bent and deformed by forming a slit 8b in the operation portion 8B. -2 is two engagement grooves 2a-1 and 2a formed above and below the guide portion 2a formed on the inner surface of the handle portion 2B of the housing 2 (locations corresponding to the first position and the second position). -2 is selectively coupled to give a sense of moderation to the movement of the switching lever 8.

  As described above, in this embodiment, since the moderation portion 8a is provided on the trigger 6 side of the operation portion 8B of the switching lever 8, the end surface 8c on the counter-trigger 6 side (left side in FIGS. 5 and 6) of the operation portion 8B. No protrusion protrudes from the end face 8c, and the end face 8c is a flat face.

Thus, when the rotational speed (output) of the motor 4 is not limited, the operating element 8C of the switching lever 8 shown in FIG. 1 is pushed downward, and the switching lever 8 is moved to the first position (“ At this time, as shown in FIG. 3, the engagement protrusion 8a-2 of the moderation portion 8a is engaged with the engagement groove 8a-2 below the guide portion 2a, and the switching lever 8 is switched. The member 8A does not obstruct the movement of the trigger 6 by retreating from the movement path 6a of the trigger 6 as shown. Therefore, in this state, the trigger 6 can be pulled to the maximum stroke, and the rotation speed (output) of the motor 4 can be increased to the maximum value for work.

  On the other hand, in order to prevent problems such as cutting of the screw head and excessive screwing, the maximum stroke of the motor 4 is regulated by restricting the maximum stroke of the trigger 6 according to the size of the screw, the material of the material to be tightened, the finishing degree, etc. When it is necessary to suppress the output) below a certain value, the operation element 8C of the switching lever 8 shown in FIG. 1 is pushed upward, so that the switching lever 8 is moved from the first position (the “P” position in FIG. 1). It is moved to the second position ("S" position in FIG. 1). At this time, as shown in FIG. 4, the engagement protrusion 8a-2 of the moderation portion 8a engages with the engagement groove 2a-1 above the guide portion 2a to give a sense of moderation to the movement of the switching lever 8. The switching member 8A of the switching lever 8 protrudes into the movement path 6a of the trigger 6 as shown in the figure, restricting the movement of the trigger 6, and preventing further movement of the trigger 6. Therefore, in this state, the trigger 6 cannot be pulled to the maximum stroke, the rotation speed (output) of the motor 4 is suppressed to a predetermined value or less, and problems such as cutting of the screw head and excessive screwing can be prevented.

  In the above, in the impact driver 1 according to the present invention, since the moderation portion 8a of the switching lever 8 is provided on the trigger 6 side, the switching member 8A and the operation portion 8B overlap in the width direction as shown in FIG. The width dimension B of the switching lever 8 can be reduced with respect to the width dimension B ′ of the conventional switching lever 108 shown in FIG. 7 (B <B ′), and the installation space is reduced. The switching lever 8 can be accommodated in the handle portion 2B of the housing 2 in a compact manner.

  Further, as a result of providing the moderation portion 8a of the switching lever 8 on the trigger 6 side as described above, the end surface 8c on the counter-trigger 6 side of the switching lever 8 can be a flat surface, and the outside of the flat end surface 8c. More specifically, a wiring space can be secured in the space between the guide portion 2b protruding from the inner surface of the handle portion 2B of the housing 2 and the inner wall of the handle portion 2B, as shown in FIGS. Thus, the two lead wires 19 routed from the battery 10 to the LED 18 for illumination can be wired in the space.

  Although the present invention has been described with respect to the embodiment in which the present invention is applied to a cordless impact driver including a rechargeable battery, the present invention can be similarly applied to a corded impact driver. Further, the application of the present invention is not limited only to the impact driver, and it is needless to say that the present invention can be widely applied to other electric tools such as a driver, a drill, a circular saw, and a jigsaw.

It is a left view of the impact driver which concerns on this invention. It is right side sectional drawing which shows the internal structure of the impact driver which concerns on this invention. It is a right side sectional view showing the state where the change lever of the impact driver concerning the present invention was changed to the high speed side. It is a right side sectional view showing the state where the change lever of the impact driver concerning the present invention was changed to the low speed side. It is a perspective view of the change lever of the impact driver concerning the present invention. It is a front view of the change lever of the impact driver concerning the present invention. It is a front view of the switching lever of the conventional impact driver.

Explanation of symbols

1 Impact driver (electric tool)
2 Housing 2A Housing Body 2B Housing Handle 2a, 2b Guide 2a-1 Engaging Groove 2a-2 Engaging Groove 3 Hammer Case 4 Motor (Drive Source)
4a Motor output shaft (motor shaft)
5 Planetary gear mechanism (reduction mechanism)
6 Trigger 6a Trigger movement path 7 Switch 8 Switching lever 8A Switching lever switching member 8B Switching lever operation section 8C Switching lever operation element 8a Switching lever moderation section 8a-1 Vertical section of moderation section 8a-2 Moderation section Engagement projection 8b Slit of operation unit 8c End surface of operation unit 9 Battery receiver 10 Battery 11 Lead wire 12 FET
13 Spindle 13a Spindle cam groove 14 Hammer 14a Hammer cam groove 15 Ball 16 Spring 17 Anvil 18 LED
19 Lead wire

Claims (1)

A motor that is a drive source; a speed reduction mechanism that decelerates rotation of the motor; and a striking mechanism that converts rotation of the motor decelerated by the speed reduction mechanism into a rotational striking force and transmits it to the tip tool, The motor rotation speed is varied according to the trigger stroke, and the switching lever is selectively moved to the first position on the high speed side and the second position on the low speed side to switch the maximum stroke of the trigger in two stages. In the electric tool which is possible and is provided with a moderation part which gives a moderation feeling to the movement of the switching lever to the first and second positions,
The power tool characterized in that the moderation portion is provided on the trigger side, and the end surface on the counter-trigger side of the switching lever is a flat surface.

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