JP2009078317A - Rotary striking tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary striking tool which allows an operator to carry out manual screwing, and exerts a good finishing state. <P>SOLUTION: There is provided an impact driver (rotary striking tool) which actuates a striking mechanism by a driving force of a motor to strike an anvil (output shaft) 4, and applies a rotary striking force to a front tool mounted on the anvil 4. A space is secured between an internal peripheral surface of a cylindrical sleeve (bearing member) 12 which rotatably supports the anvil 4, and an external peripheral surface of the anvil 4, and rollers (lock members) 14, 15 are movably arranged in the space. A switch (release member) 16 for moving the rollers 14, 15 in the space is provided. The switch 16 sets the roller 14 (15) to a locking position where rotation of the anvil 4 is locked, and to a release position where locking of the rotation is canceled. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rotary impact tool capable of easily locking and releasing an output shaft.

  Rotating impact tools are widely used nowadays because they have features such as small reaction and high tightening ability. Here, an impact driver as an example of a conventional rotary impact tool will be described with reference to FIG.

  FIG. 7 is a side sectional view of a conventional impact driver. The illustrated impact driver 1 ′ has a battery pack 2 as a power source, operates a striking mechanism portion by a driving force of a motor 3, and strikes an anvil 4. A rotational impact force is applied to the tool 5. That is, the rotation of the motor 3 is decelerated through the planetary gear mechanism 6 and transmitted to the spindle 7, and the spindle 7 is driven to rotate.

  In the striking mechanism, the spindle 7 and the hammer 8 are connected by a cam mechanism constituted by a cam ball 9 and a V-shaped cam groove 7a, and the hammer 8 is always in the distal direction (rightward in FIG. 7) by a spring 10. It is energized. Thereby, when the spindle 7 and the hammer 8 are relatively twisted, the hammer 8 moves backward to the motor 3 side, and when the hammer 8 is released from the twist, it rotates and advances while being accelerated by the spring 10. Here, symmetrical projections (not shown) are formed at two locations on the rotation plane of the hammer 8 and the anvil 4. In addition, the rotation direction of the screw 11, the tip tool 5, and the anvil 4 is mutually restrained.

  Thus, the rotation hitting operation is performed as follows.

  That is, the rotation of the spindle 7 is transmitted to the hammer 8 via the cam mechanism, and both start rotating together. Then, the protrusions of the hammer 8 and the anvil 4 are engaged with each other before the spindle 7 and the hammer 8 are rotated halfway, the spindle 7 continues to rotate, and the hammer 8 is stopped from rotating by the anvil 4. As a result, the spindle 7 and the hammer 8 are relatively twisted, and the hammer 8 starts to retract while the spring 10 is contracted. The hammer 8 starts to advance while being rapidly accelerated in the rotational direction by the elastic energy stored in the spring 10 in addition to the rotational force of the spindle 7. Then, while the hammer 8 is accelerated, the protrusions of the hammer 8 and the anvil 4 are engaged again. At this time, a strong rotational impact force is applied to the anvil 4, and this rotational impact force is It is transmitted to the tip tool 5 and the screw 11 and the hammer 8 starts to retract again.

  By the way, in such an impact driver 1, the configuration in which the rotation of the anvil 4 as the output shaft can be locked enables the impact driver 1 ′ to be used as a hand-operated type, and the screw 11 is used for the rotational impact force. This is very useful for performing auxiliary tightening for improving the finished state when the screw is not fully tightened or when the head of the screw 11 is not finished with the same surface as the surface of the material to be fastened W such as wood.

  However, when the screw 11 is tightened by hand with the impact driver 1 ′ shown in FIG. 7, when the tip tool 5 is applied to the screw 11 and the operator grasps the driver body and rotates it, the screw 11 is rotated. Is transmitted to the motor 3 via the anvil 4, the hammer 8, the spring 10, the spindle 7 and the planetary gear mechanism 6, and therefore, it is impossible to transmit a force exceeding the torque due to the friction of the transmission path, and is necessary for the screw 11. There was a problem that sufficient torque could not be transmitted.

On the other hand, conventionally, in an electric driver or an electric wrench that does not include a rotary impact mechanism, Patent Document 1 discloses a lock between the inner peripheral surface of the ring body surrounding the output shaft side member and the outer peripheral surface of the output shaft side member. There has been proposed a configuration in which a wedge-shaped space portion that allows biting and floating of the member is formed, and a release member that pushes the lock member toward the floating region in the wedge-shaped space portion is provided on the input shaft side member.
Japanese Patent Publication No. 6-053350

  As described above, with conventional rotary impact tools, the screw could not be tightened by hand, so it might not be tightened by the rotary impact force, or the head of the screw might not be finished on the same surface as the surface of the material to be fastened, such as wood. There was a problem that it was generated and a good finished state could not be obtained.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a rotary impact tool that can be screwed by hand and can obtain a good finished state.

  In order to achieve the above-mentioned object, the invention according to claim 1 is a rotation which applies a rotating striking force to a tip tool mounted on the output shaft by operating the striking mechanism by the driving force of the motor and striking the output shaft. In the impact tool, a lock member is movably provided in a space formed between an inner peripheral surface of a cylindrical bearing member that rotatably supports the output shaft and an outer peripheral surface of the output shaft. A release member for moving the lock member is provided, and the release member can be set at a lock position where the lock member locks the rotation of the output shaft and a release position where the rotation lock is released.

  According to a second aspect of the present invention, in the first aspect of the invention, when the release member is set at the release position, a motor-driven operation is possible, and when the release member is at the lock position, a screw tightening operation and a screw loosening operation are performed manually. Is possible.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the lock member is constituted by two or more rollers, and the rollers are held by the release member so as to be able to roll. .

  According to the present invention, even in a rotary impact tool having a rotary impact mechanism portion, if the release member is set at the lock position, the rotation of the output shaft is locked by the lock member. Even if the screw does not tighten due to the rotating impact force, or even if the head of the screw cannot be finished as the same surface as the surface of the material to be fastened, such as wood, the screw is tightened to the end by additional tightening, The head can be finished with the same surface as the surface of the material to be fastened, such as wood, and a good finished state can be obtained.

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

  FIG. 1 is a side sectional view of an impact driver tip as an embodiment of the rotary impact tool according to the present invention, FIG. 2 is a sectional view taken along line AA in FIG. 1 (with the switch removed), and FIG. 4 and 6 are cross-sectional views taken along line AA in FIG. 1, FIG. 4 shows a screw tightening / loosening operation state driven by a motor, FIG. 5 shows a screw tightening state by hand turning, and FIG. The screw is loosened by.

  Since the basic configuration of the impact driver 1 according to the present embodiment is the same as that of the conventional impact driver 1 ′ shown in FIG. 7, the same components as those shown in FIG. Only the features of the present invention will be described below.

  The impact driver 1 according to the present embodiment is characterized in that a locking mechanism for an anvil 4 as an output shaft is added. That is, the cylindrical sleeve 12 that is a bearing member that rotatably holds the anvil 4 is formed with a roller accommodating portion 12A as shown in FIG. 2, and the roller accommodating portion 13A is also formed on the inner peripheral surface of the hammer case 13. Is formed. These roller accommodating portions 12A and 13A are formed to face each other, and rollers 14 and 15 as locking members are accommodated and held therein. Further, the hammer case 13 is formed with a switch housing portion 13B, and a switch 16 shown in FIG. 3 as a release member is held in the switch housing portion 13B so as to be movable in the rotation direction of the anvil 4 (FIG. 4 to 6).

  As shown in FIG. 3, the switch 16 has two arms 16b and 16c, and holds two rollers 14 and 15 in two spaces formed by a base 16d. The switch 16 is held by the roller accommodating portion 13A of the hammer case 13 and the hammer cover 17 with a slight gap and is restricted so as not to move in the axial direction. Further, three switch lock grooves 13a, 13b, 13c for positioning the switch 16 are formed on the inner peripheral surface of the hammer case 13, and the switch 16 is formed in these switch lock grooves 13a, 13b, 13c. The projections 16a thus engaged are selectively engaged.

  The arm 16c of the switch 16 is set to be larger than the roller accommodating portion constituted by the roller accommodating portion 12A of the sleeve 12 and the roller accommodating portion 13A of the hammer case 13, and the tip of the arm 16c is always in contact with the sleeve 12. ing. Therefore, the switch 16 is held in a state where it is always elastically compressed between the position where the protrusion 16a is engaged with any one of the switch lock grooves 13a, 13b, and 13c and the tip of the arm 16c, and is freely It is in a state where it cannot move.

In the impact driver 1 configured as described above, each operation of screw tightening and screw loosening by motor drive, screw tightening by screwing and screw loosening will be described below with reference to FIGS.
(1) Screw tightening / screw loosening by motor drive:
When screw tightening and screw loosening operations are performed by motor driving, the switch 16 is set at the center as shown in FIG. That is, when the protrusion 16a is engaged with the switch lock groove 13a, the rollers 14 and 15 cannot contact the anvil 4 because of the base 16d of the switch 16, and the anvil 4 can freely rotate. become. Therefore, it becomes possible to transmit the rotational force from a motor (not shown) directly to the screw 11 shown in FIG.
(2) Screw tightening by hand:
When the screw tightening operation is performed manually, the operator moves the switch 16 in the arrow a1 direction as shown in FIG. 5 and engages the protrusion 16a with the switch lock groove 16b.

Then, with the movement of the switch 16, the roller 14 is also pushed out by the arm 16c and moves in the direction of the arrow a1, and simultaneously contacts the roller fixing wall 13C of the hammer case 13 and the outer surface of the anvil 4. In this state, when the operator rotates the driver main body in the direction of the arrow a2, the rotational force of the driver main body is transmitted from the hammer case 13 to the anvil 4 via the roller 14 along the path indicated by the arrow a3. The screw 11 shown in FIG. 1 is rotated in the same direction by rotating in the direction of the arrow a4.
(3) Loosening the screw by hand When the screw is loosened by hand, the operator moves the switch 16 in the direction of the arrow b1 as shown in FIG. 6, and engages the protrusion 16a with the switch lock groove 16c.

  Then, as the switch 16 moves, the roller 15 is also pushed out by the arm 16c and moves in the direction of the arrow b1, and simultaneously contacts the roller fixing wall 13C of the hammer case 13 and the outer surface of the anvil 4. In this state, when the operator rotates the driver main body in the direction of the arrow b2, the rotational force of the driver main body is transmitted from the hammer case 13 to the anvil 4 via the roller 15 along the path indicated by the arrow b3. Rotating in the direction of arrow b4, the screw 11 shown in FIG. 1 is rotated in the same direction.

  As described above, according to the present embodiment, by changing the set position of the switch 16, it is possible to easily and reliably select a screw tightening / screw loosening operation by motor driving or a screw tightening / screw loosening operation by hand turning. Is possible. Therefore, even if the screw 11 is not tightened due to the rotational impact force or the head of the screw 11 cannot be finished with the same surface as the surface of the material W to be fastened such as wood, the screw 11 is tightened. By tightening to the end, it is possible to finish the head as the same surface as the surface of the material to be fastened W such as wood, and a good finished state can be obtained.

  Although the present invention has been described with respect to an embodiment in which the present invention is applied to an impact driver, it is needless to say that the present invention can be similarly applied to any other rotary impact tool having a rotary impact mechanism. .

It is side sectional drawing of the impact driver front-end | tip part which concerns on this invention. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1 (a state in which a switch is removed). It is a front view of a switch. FIG. 2 is a cross-sectional view taken along the line AA of FIG. It is the sectional view on the AA line of FIG. 1 which shows the screw fastening state by manual rotation. It is the sectional view on the AA line of FIG. 1 which shows the screw loosening state by manual rotation. It is a sectional side view of the conventional impact driver.

Explanation of symbols

1 Impact driver (rotary impact tool)
2 Battery pack 3 Motor 4 Anvil (output shaft)
5 Tip tool 6 Planetary gear mechanism 7 Spindle 7a V-shaped cam groove 8 Hammer 9 Cam ball 10 Spring 11 Screw 12 Sleeve (bearing member)
12A Roller housing portion of sleeve 13 Hammer case 13A Roller housing portion of hammer case 13B Switch housing portion of hammer case 13C Roller fixing wall of hammer case 13a to 13c Switch lock groove of hammer case 14, 15 Roller (lock member)
16 switch (release member)
16a Switch protrusion 16b, 16c Switch arm 16d Switch base 17 Hammer cover W Fastened material

Claims (3)

In the rotary hitting tool that operates the hitting mechanism by the driving force of the motor and gives the rotary hitting force to the tip tool mounted on the output shaft by hitting the output shaft.
A lock member is movably provided in a space formed between an inner peripheral surface of a cylindrical bearing member that rotatably supports the output shaft and an outer peripheral surface of the output shaft, and the lock member is disposed in the space. A rotary impact tool comprising a release member for moving, and the release member can be set at a lock position where the lock member locks the rotation of the output shaft and a release position where the rotation lock is released.   2. The rotary impact according to claim 1, wherein when the release member is set at a release position, a motor drive operation is possible, and when the release member is at a lock position, a screw tightening operation and a screw loosening operation can be performed manually. tool.   3. The rotary impact tool according to claim 1, wherein the lock member is composed of two or more rollers, and the rollers are held by the release member so as to be able to roll.

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