JP5340881B2 - Impact tool - Google Patents

Description

  The present invention relates to an impact tool such as an impact driver that generates a rotational impact force on an anvil protruding forward of a housing.

  In impact tools such as impact drivers, a spindle that is rotated by a motor in a housing and a ball that is externally mounted on the spindle and fits over a groove provided on both spindles are connected to each other, and a pair of claws are projected on the front surface. The hammer is installed on the same axis, is pivotally supported by the housing, the front end where the bit is mounted is projected forward of the housing, and a pair of arms are formed radially at the rear end. And a coil spring that urges the forward position to be engaged. That is, when the torque of the anvil increases, the hammer moves backward by the guide of the ball rolling in the groove and moves away from the arm, and moves forward while rotating by the bias of the coil spring and engages the arm. By repeating, the rotary hitting force (impact) is intermittently generated in the anvil.

In such a striking tool, for example, when screwing in a pilot hole, there are different tools such as first drilling a pilot hole with an electric drill and then screwing with a striking tool such as an impact driver. It is used properly. Therefore, preparation and replacement of tools are necessary, and workability is reduced. If a drill bit is attached to the impact driver, drilling is possible, but if the workpiece is relatively brittle, such as a tile, there is a risk of damage due to the impact.
Therefore, as shown in Patent Document 1, a striking tool has been invented that is provided with hammer restricting means for arbitrarily restricting the movement of the hammer in the axial direction so that the hammer and the arm are always engaged. According to this striking tool, a drill mode is obtained by the hammer restricting means, and it is not necessary to use different tools.

Japanese Patent No. 2828640

  However, the hammer restricting means disclosed in Patent Document 1 has a ring-shaped operation handle on the outer periphery of a gear case that houses the striking mechanism, and an engagement pin provided on the operation handle is provided in an inclined shape provided on the gear case. The cam groove is penetrated and locked to an annular concave groove provided on the outer periphery of the hammer. That is, the drill mode is obtained by restricting the retraction of the hammer by moving the engagement pin forward by the rotation of the operation handle. Therefore, when switching the mode, it is necessary to hold the tool body with one hand while rotating the operation handle with the other hand, which makes the switching operation troublesome. In particular, when working with a screw or the like in one hand, each time the mode is switched, the user performs a switching operation with both hands each time the mode is switched.

  Therefore, the present invention has an object to provide a striking tool that can be easily switched with one hand as well as being able to obtain a drill mode and is excellent in usability.

In order to achieve the above-mentioned object, the invention according to claim 1 is characterized in that the front of the handle projects into the lower part of the housing into the housing, the pawl engages the arm at the advanced position where the arm engages the arm, and then A stopper member that can slide between a protruding position that regulates retraction and a retreat position that allows the hammer to retreat away from the hammer, a biasing means that biases the stopper member to the retreat position, and a stopper that is operated by an external operation And an operation member that slides the member from the retracted position to the protruding position against the urging force of the urging means, and when the stopper member is moved to the protruding position by the operating member, the movement of the hammer is restricted. Thus, the engagement / disengagement operation of the hammer with respect to the arm is prevented, and the anvil is rotated integrally with the spindle.
According to a second aspect of the present invention, in the configuration of the first aspect, the stopper member is a shaft body that is rotatably held by a bearing provided in the housing.
According to a third aspect of the present invention, in the configuration of the first or second aspect, a thrust bearing is provided at the front end in the housing so as to contact the front surface of the arm and penetrate the anvil.

According to invention of Claim 1, in addition to the original impact mode, it can be used also in the drill mode which does not generate | occur | produce an impact. Therefore, it is not necessary to use different tools, and workability is improved. In particular, here, the mode can be switched by operating the operating member with one hand holding the handle, so there is no need to interrupt the work each time the mode is switched and the mode can be switched easily with one hand. Excellent.
According to the invention of claim 2, in addition to the effect of claim 1, in the drill mode, the stopper member also rotates with the rotation of the hammer. Wear of the stopper member is suppressed and durability can be maintained.
According to the invention of claim 3, in addition to the effect of claim 1 or 2, the forward pressing force to the anvil generated by the forced retraction regulation of the hammer is eased, and the torcross generated in the anvil is effectively reduced. It becomes possible to suppress.

It is a partial longitudinal cross-sectional view of the impact driver of the form 1 (drill mode). FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, where (A) shows a drill mode and (B) shows an impact mode. It is a longitudinal cross-sectional view of the front part of the impact driver of the form 1 (impact mode). It is a partial longitudinal cross-sectional view of the impact driver of form 2 (drill mode). It is explanatory drawing of a switching lever and a mode switching block. It is a longitudinal cross-sectional view of the front part of the impact driver of form 2 (impact mode). FIGS. 4A and 4B are cross-sectional views taken along line BB in FIG. 4, where FIG. 4A shows a drill mode and FIG. It is a partial longitudinal cross-sectional view of the impact driver of the form 3 (drill mode). It is explanatory drawing of a switching lever and a mode switching plate. It is CC sectional view taken on the line of FIG. 8, (A) shows drill mode, (B) shows each in impact mode.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the second and subsequent embodiments, the same components as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.
[Form 1]
As shown in FIG. 1, an impact driver 1A, which is an example of an impact tool, is formed by assembling left and right half housings 3 and 3, and a main body housing 2 that houses a motor 4, and a front of the main body housing 2 (see FIG. 1). 1) and is provided with a hammer case 6 having a bell-shaped cross section which is a front housing for housing the spindle 7, the striking mechanism 8, and the anvil 9. Below the main body housing 2, a handle 10 having a battery pack (not shown) as a power source attached at the lower end extends downward, and a switch 11 having a trigger 12 is accommodated in the upper portion of the handle 10. Further, an extension portion 13 that covers the lower portion of the hammer case 6 is formed below the hammer case 6 in the main body housing 2 and between the trigger 12. A light unit 14 is attached.

  An output shaft 5 of the motor 4 is supported by a gear case 15 assembled to the main body housing 2, and a pinion 16 that projects into the hammer case 6 is fitted to the output shaft 5. In the hammer case 6, the spindle 7 has a hollow portion 17 into which the pinion 16 is inserted at the rear axis, and two planetary gears 18 and 18 that revolve in the internal gear 19 are provided on the outer periphery of the spindle 7. It is held and meshed with the pinion 16. The rear end portion of the spindle 7 is supported coaxially with the output shaft 5 by a ball bearing 20 supported by the gear case 15.

  A pair of arms 21 and 21 extend radially at the rear end of the anvil 9 in the hammer case 6. The striking mechanism 8 is externally mounted on the front end of the spindle 7 and has a hammer 22 projecting from a front surface with a pair of claws 23, 23 that engage with the arms 21, 21, and the claw 23 engages the arm 21 with the hammer 22. And a coil spring 24 that urges the forward movement position. The hammer 22 is recessed in the inner peripheral surface thereof from the front end toward the rear, and the angled grooves 25 and 25 tapering at the rear end, and the V-shape in which the front end is recessed forward on the outer peripheral surface of the spindle 7. It is connected to the spindle 7 via balls 27 and 27 which are fitted over the grooves 26 and 26.

On the other hand, the anvil 9 is pivotally supported by a metal bearing 28 held at the front end of the hammer case 6, and a small-diameter portion 30 protruding from the front end of the spindle 7 is fitted into a bearing hole 29 formed in the rear shaft center. In combination, the front end of the spindle 7 is coaxially supported. In addition, a thrust needle bearing 31 through which the anvil 9 penetrates and the front surfaces of the arms 21 and 21 abut is provided at the front front end of the hammer case 6 and behind the metal bearing 28 to support the arms 21 and 21 in the thrust direction. doing.
In addition, a bit mounting hole 32 is formed at the front end of the anvil 9 protruding from the hammer case 6, and a chuck mechanism including a ball 33 and a sleeve 34 for retaining the bit inserted into the mounting hole 32. Is provided.

  As shown in FIG. 2, a stopper pin 35, which is a stopper member of the shaft body, penetrates in the vertical direction at the front side of the handle 10 and at the lower part of the hammer case 6. 36 is supported so as to be rotatable and movable in the vertical direction. Further, in the stopper pin 35, a coil spring 38 serving as an urging means is externally provided between the lower surface of the ball bearing 36 and the flange 37 provided at the lower end of the stopper pin 35, and the stopper pin 35 is moved downward from the hammer case 6. It is energized in the protruding direction.

Further, a through hole 39 penetrating in the left-right direction is formed between the stopper pin 35 and the trigger 12 at the base end of the extending portion 13, and the stopper pin urged downward in the through hole 39. A mode switching button 40 as an operation member with which 35 abuts is loosely inserted.
The mode switching button 40 is a rod-shaped body having a concave portion 41 with which the lower end of the stopper pin 35 is locked on the upper surface. The concave portion 41 is deeper than the first abutting surface 42 and the first abutting surface 42. The shallow second contact surface 43 and the inclined surface 44 that connects the both contact surfaces 42 and 43 have a stepped shape arranged in parallel in the left-right direction. Reference numeral 45 denotes a ball which is provided at the lower end of the stopper pin 35 and protrudes from the lower surface and comes into contact with the recess 41.

Therefore, the mode switching button 40 can be slid left and right within a range in which the stopper pin 35 can relatively move in the recess 41 by selectively pressing the left and right end portions exposed from the through hole 39.
Here, when the mode switching button 40 is slid to the left end where the first contact surface 42 is positioned below the stopper pin 35, the stopper pin 35 is attached to the coil spring 38 as shown in FIGS. The ball 45 is lowered to a position where it comes into contact with the first contact surface 42 by the force, and the upper end is retracted from the hammer case 6 (retracted position).
On the other hand, when the mode switching button 40 is slid to the right end where the second contact surface 43 is positioned below the stopper pin 35, the stopper pin 35 has the ball 45 relative to the stopper pin 35, as shown in FIGS. The inclined surface 44 rolls on the second contact surface 43 to rise against the bias of the coil spring 38, and the upper end protrudes into the hammer case 6 (projection position). In this state, the upper end of the stopper pin 35 is engaged with the rear surface of the hammer 22 in the forward movement position.

  In the impact driver 1A configured as described above, when the mode switch button 40 is slid to the right end and the stopper pin 35 is moved to the retracted position in FIG. 2B as described above, the hammer 22 is allowed to move backward. Impact mode. Therefore, when the motor 12 is driven by operating the trigger 12 provided on the handle 10, the rotation of the output shaft 5 is transmitted to the spindle 7 via the planetary gears 18, 18 and the spindle 7 is rotated. The spindle 7 rotates the hammer 22 via the balls 27 and 27 and rotates the anvil 9 with which the hammer 22 is engaged. Therefore, the spindle 7 can be tightened with a bit attached to the tip of the anvil 9.

When the tightening of the screw is advanced and the torque of the anvil 9 is increased, the rotation of the hammer 22 and the rotation of the spindle 7 are displaced, so that the hammer 22 rolls the balls 27 and 27 along the V-shaped grooves 26 and 26. Accordingly, the coil spring 24 moves backward against the bias of the coil spring 24 while rotating relative to the spindle 7.
When the claw 23 of the hammer 22 is released from the arm 21, the hammer 22 moves forward by rotating the balls 27 and 27 toward the tips of the V-shaped grooves 26 and 26 by the bias of the coil spring 24. . Therefore, the claw 23 of the hammer 22 is engaged with the arm 21 again to generate a rotational impact force (impact). Retightening is performed by repeatedly engaging and disengaging the anvil 9.

On the other hand, when the mode switching button 40 is slid to the left end and the stopper pin 35 is moved to the protruding position of FIG. 2A, the drill mode is established in which the stopper 22 is engaged to restrict the backward movement of the hammer 22. Therefore, when the motor 12 is driven by operating the trigger 12, the hammer 22 rotates with the rotation of the spindle 7, and the hammer 22 and the anvil 9 rotate together.
Even if the torque of the anvil 9 increases, the hammer 22 engages with the stopper pin 35 and the relative rotation with the spindle 7 is restricted, so that the hammer 22 does not engage / disengage with respect to the arm 21. Therefore, no impact occurs and the anvil 9 rotates integrally with the spindle 7.

In this drill mode, a rotational force acts on the stopper pin 35 engaged with the rotating hammer 22, but the stopper pin 35 is pivotally supported by the ball bearing 36, so that the stopper pin 35 is rotated as the hammer 22 rotates. Also rotates. Therefore, rotational resistance to the hammer 22 due to friction with the stopper pin 35 is suppressed, and wear of the hammer 22 and the stopper pin 35 is also suppressed.
Further, by forcibly restricting the backward movement of the hammer 22 by the stopper pin 35, a forward reaction force is generated on the spindle 7 via the ball 27, and this reaction force is transmitted to the anvil 9 so that the arms 21 and 21 are hammered. Since it is pressed by the front end in case 6, it connects with a torcloth. However, since the front surfaces of the arms 21 and 21 are received by the thrust needle bearing 31 here, the pressing force applied to the hammer case 6 is alleviated and the torcross generated in the anvil 9 is effectively suppressed.

  As described above, according to the impact driver 1A of the first aspect, the protrusion protrudes into the hammer case 6 at the lower portion of the hammer case 6 in front of the handle 10 and engages with the hammer 22 at the forward movement position to restrict the backward movement. A stopper pin 35 that is slidable between the position and the retreat position that allows the retraction of the hammer 22, a coil spring 38 that urges the stopper pin 35 to the retreat position, and the stopper pin 35 that is operated by an external operation. And a mode switching button 40 that slides from the retracted position to the projecting position against the bias of 38, and when the stopper pin 35 is moved to the projecting position by the mode switching button 40, the hammer 22 is retracted. By restricting and preventing the hammer 22 from engaging and disengaging with the arms 21 and 21, the anvil 9 is rotated integrally with the spindle 7. In the the fact as, in addition to the original impact mode, can be used in drill mode where impact does not occur. Therefore, it is not necessary to use different tools, and workability is improved. In particular, since the mode switching can be performed by sliding the mode switching button 40 right above the trigger 12 to the left and right with one hand holding the handle 10, there is no need to interrupt the operation each time the mode is switched. However, the mode can be easily switched and it is easy to use.

Further, since the stopper pin 35 is a shaft body that is rotatably held by a ball bearing 36 provided on the hammer case 6, the stopper pin 35 also rotates as the hammer 22 rotates in the drill mode. Rotational resistance to the hammer 22 due to friction with the stopper pin 35 and wear of the hammer 22 and the stopper pin 35 are suppressed, and durability can be maintained.
Furthermore, by providing a thrust needle bearing 31 at the front end of the hammer case 6 so as to contact the front surfaces of the arms 21 and 21 and through which the anvil 9 penetrates, It becomes possible to relieve the forward pressing force and effectively suppress the torcross generated in the anvil 9.

  In the first embodiment, the positions of the first contact surface and the second contact surface provided on the stopper pin may be reversed left and right, and the mode switching button is not a single member, for example, an inner portion having a recess and a through hole You may form by several members, such as assembling | attaching the outer part which slides inside.

[Form 2]
The impact driver 1B shown in FIG. 4 is different from the first embodiment in that the operation member here is not a left-right slide but a rotation type. First, a fulcrum pin 50 is fixed downward in front of the stopper pin 35 and below the hammer case 6, and an intermediate portion of the switching lever 51 is pivotally attached to the fulcrum pin 50. 13 is connected to the rear end of the switching lever 51, while an arc-shaped mode switching block 52 having a recess 41 including first and second contact surfaces 42, 43 and an inclined surface 44 formed on the upper surface is connected. Has been. That is, by rotating the tip of the switching lever 51 in the left-right direction, the mode switching block 52 is moved in the left-right direction around the fulcrum pin 50 as shown in FIG. The second contact surfaces 42 and 43 can be selected. The switching lever 51 and the mode switching block 52 serve as operation members.

Therefore, when the switching lever 51 is rotated to the left side and the mode switching block 52 is moved to the right end in the extending portion 13 as shown by a two-dot chain line in FIG. 5, as shown in FIGS. 6 and 7B. In addition, since the first contact surface 42 is located below the stopper pin 35, the stopper pin 35 moves to the retracted position, and the impact mode in which the hammer 22 is allowed to retreat is set.
On the other hand, when the switching lever 51 is rotated to the right as shown by the solid line in FIG. 5 to move the mode switching block 52 to the left end in the extending portion 13, as shown in FIGS. 4 and 7A, Since the second contact surface 43 is positioned below the stopper pin 35, the stopper pin 35 that has moved to the protruding position engages with the hammer 22 and is in a drill mode in which its retreat is restricted. The operation in each mode is the same as in the first mode.

  As described above, the impact driver 1B according to the second aspect can be used in the drill mode in which no impact occurs in addition to the original impact mode. Therefore, it is not necessary to use different tools, and workability is improved. Also, here, since the mode can be switched by swinging the switching lever 51 right above the trigger 12 to the left and right with one hand holding the handle 10, there is no need to interrupt the operation each time the mode is switched. The same effect as in the first mode can be obtained in which the mode can be easily switched with one hand and the usability is excellent.

  In the second embodiment, the first contact surface and the second contact surface provided on the mode switching block may be reversed left and right, or the switching lever and the mode switching block are formed in a disc shape as a whole. Changes are also possible.

[Form 3]
The impact driver 1 </ b> C shown in FIG. 8 is different from Embodiment 2 in that two stopper pins 35 that can protrude and retract in the radial direction of the hammer case 6 are provided. That is, as shown in FIG. 10, here, a pair of stopper pins 35 and 35 are pivotally supported by ball bearings 36 at symmetrical positions inclined by a predetermined angle with respect to a vertical line passing through the axis of the spindle 7. The coil spring 38 is urged to the lower retracted position. Further, the extending portion 13 is formed in a circular arc shape in front view on the lower side of the hammer case 6 including the stopper pins 35, 35, and the stopper pins 35, 35 are respectively locked in the extending portion 13. A mode switching plate 53 having recesses 41, 41 formed at both ends is provided.

  The concave portions 41 of the mode switching plate 53 are also formed with first and second contact surfaces 42, 43 and an inclined surface 44 connecting the two, respectively, in the extending portion 13 in the circumferential direction of the hammer case 6. It is movable. In addition, a long hole 54 extending in the front-rear direction is formed in an intermediate portion of the mode switching plate 53, and a pin 55 erected at the rear end of the switching lever 51 is loosely inserted into the long hole 54. The switching plate 53 is connected to the switching lever 51. Therefore, when the switching lever 51 is rotated left and right, the amount of movement of the pin 55 in the front-rear direction is absorbed by the long hole 54, and the mode switching plate 53 slides in the left-right direction.

That is, when the mode switching plate 53 is slid to the left end in the extending portion 13 by rotating the switching lever 51 to the right side as shown by a two-dot chain line in FIG. Since the first contact surface 42 is located below each stopper pin 35, each stopper pin 35 moves to the retracted position, and the impact mode is allowed to allow the hammer 22 to move backward.
On the other hand, when the switching lever 51 is rotated to the left as shown by the solid line in FIG. 9 and the mode switching plate 53 is slid to the right end in the extending portion 13, as shown in FIG. Since the contact surface 43 is positioned below each stopper pin 35, each stopper pin 35 that has moved to the protruding position engages with the hammer 22 and is in a drill mode in which retraction is restricted. The operation in each mode is the same as in the first mode.

As described above, the impact driver 1C according to the third aspect can be used in the drill mode in which no impact occurs in addition to the original impact mode. Therefore, it is not necessary to use different tools, and workability is improved. Also, here, since the mode can be switched by swinging the switching lever 51 right above the trigger 12 to the left and right with one hand holding the handle 10, there is no need to interrupt the operation each time the mode is switched. The same effect as in the first mode can be obtained in which the mode can be easily switched with one hand and the usability is excellent.
Further, since two stopper pins 35 are used, there are advantages that the durability is higher than those of the first and second embodiments and the reliability in the drill mode is excellent.

  In the third embodiment as well, the first contact surface and the second contact surface provided on the mode switching plate may be reversed left and right, or the design change such that the switching lever and the mode switching plate are formed in a disc shape as a whole. Is also possible.

And, in common with each form, the stopper member is not limited to the shaft body, and a plate-like body is adopted so as to protrude into and out of the housing, or an elastic material or a weight is used as the urging means. It can be changed. In the drill mode, the stopper member may be engaged with a recess provided on the side surface of the hammer.
In addition, for example, the housing is not limited to the main body housing and the hammer case, and the form of the housing and other mechanisms can be changed as appropriate, for example, the main body housing and the hammer case are integrated. Of course, in addition to the impact driver, the present invention can be applied to other impact tools such as an angle impact driver and an impact wrench.

  1A to 1C ・ ・ Impact driver, 2 ・ ・ Main body housing, 4 ・ Motor, 5 ・ ・ Output shaft, 6 ・ Hammer case, 7 ・ Spindle, 8 ・ ・ Blow mechanism, 9 ・ ・ Anvil, 21 ・ ・Arm, 22 ... hammer, 23 ... claw, 24 ... coil spring, 26 ... V-groove, 27 ... ball, 31 ... thrust needle bearing, 35 ... stopper pin, 36 ... ball bearing, 38 ... .. Coil spring, 39 .. Through hole, 40 .. Mode switching button, 41 .. Recess, 42 .. First contact surface, 43 .. Second contact surface, 44 .. Inclined surface, 45. 50 ·· Supporting pin, 51 ·· Switching lever, 52 ·· Mode switching block, 53 ·· Mode switching plate.

Claims (3)

A spindle that is rotated by a motor in the housing, and an anvil that is coaxially supported by the housing in front of the spindle, projects a front end to which a bit is mounted, and projects an arm radially at the rear end. And a claw that engages with the arm projecting on the front surface and is externally mounted on the spindle, moves back and forth in accordance with the torque of the anvil, engages and disengages from the arm, and the rotation of the spindle is used as a rotational impact force to the anvil. An impact tool comprising: a hammer for transmitting to a handle; and a handle projecting downward from the housing,
At the bottom of the housing in front of the handle,
A protrusion position that protrudes into the housing and engages the hammer at the forward position of the hammer where the claw engages the arm and restricts the retraction thereof, and a retreat that allows the hammer to move away from the hammer. A stopper member that can slide between positions;
Biasing means for biasing the stopper member to the retracted position;
An operation member that slides the stopper member from the retracted position to the protruding position against an urging force of the urging means by an external operation;
When the stopper member is moved to the protruding position by the operation member, the hammer is prevented from retreating to prevent the hammer from being engaged and disengaged, and the anvil is rotated together with the spindle. A striking tool characterized by   The impact tool according to claim 1, wherein the stopper member is a shaft body rotatably held by a bearing provided in the housing.   The striking tool according to claim 1, wherein a thrust bearing that abuts against the front surface of the arm and through which the anvil penetrates is provided at a front end in the housing.

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