JP5888505B2 - Tightening tool - Google Patents

Description

  The present invention relates to a tightening tool that is rotationally driven by an electric motor or the like and tightens a screw, a bolt, or the like with a rotational force of the motor, and more particularly to a tightening tool that can manually tighten a fastening member using the tightening tool after the motor is stopped.

  As a tightening tool for tightening screws, bolts, etc., an impact tool is known which transmits a rotational force of a motor to a rotating hammer and converts the hammer into a striking force by striking the hammer with an anvil. As such an impact tool, there is Patent Document 1, and when a cam for converting a rotary motion of a hammer into a retreating motion in an axial direction is formed on each of the spindle and the hammer via a steel ball and a certain tightening torque is reached. The hammer moves backward and the claws of the anvil and hammer are disengaged, and the hammer's rotational energy is energized by the energy stored in the spring that is stored when the hammer is retracted, and the hammer strikes the anvil, tightening and loosening the bolts.

JP 2011-73087 A

  The fastening force of the impact tool according to Patent Document 1 is such that the hammer strikes the anvil by the energy stored in the spring. However, in the case of a small impact tool, the tightening torque is insufficient, and in some cases, the operator may want to perform additional tightening. At that time, if another tool for hand tightening such as a screwdriver is used, the tool must be changed, which is very troublesome. Therefore, a tightening tool that enables additional tightening using a tool that operates by power has been known, but in that case, after tightening with the tightening tool, it is necessary to operate the output shaft lock button, It was necessary to release the output shaft lock after the manual tightening operation, and these switching operations were troublesome. Further, when an output shaft locking mechanism for hand-tightening is provided on an impact tool such as Patent Document 1, the structure on the tip side from the hammer becomes complicated, resulting in an increase in manufacturing cost.

  The present invention has been made in view of the above background, and an object thereof is to provide a tightening tool that can use a tool body as a tightening tool when power of a motor or the like is stopped.

  Another object of the present invention is to realize a reduction in manufacturing cost by simplifying the shape of the anvil and the periphery of the anvil in a tightening tool having a lock function for fixing the rotation of the anvil for hand tightening.

  Still another object of the present invention is to reduce a collision noise generated when a rotary impact force is transmitted from an anvil impact portion to an output shaft in a tightening tool having a lock function for fixing the rotation of an anvil for hand tightening. It is in.

  Of the inventions disclosed in the present application, typical features will be described as follows.

According to one aspect of the present invention, a housing that houses a drive source, a hammer that is driven in the rotational direction by the drive source, an anvil that is driven in the rotational direction upon contact with the hammer, and a relative rotation of the anvil relative to the housing. In a tightening tool having a lock mechanism for switching whether to lock or not, a lock release member is provided so as to be rotatable with respect to the anvil, and when the hammer rotates, the lock comes into contact with the lock release member before the hammer contacts the anvil. The mechanism is configured to release the lock, and the lock release member is configured to be rotatable between the hammer and the anvil while the hammer is in contact with the anvil. The hammer has a first protrusion that extends forward, and the anvil extends radially outward so as to contact the first protrusion and a shaft that is rotatable relative to the housing and to which the tip tool is attached. a second protrusion, the hammer is configured to unlock the lock releasing member and in contact with the locking mechanism before the first protrusion is rotated to contact with the second protrusions. The first protrusion is provided with a recess for receiving a part of the unlocking member.

  According to another feature of the invention, the clamping tool has an output shaft for holding the tip tool, the anvil and the output shaft are integrally formed, and the unlocking member is coaxial with the anvil and rotates relative to the anvil by a small angle. A cylindrical carrier member attached as possible and penetrating the output shaft was used. The lock mechanism includes a lock ring that restricts movement of the carrier member toward the output shaft, an engagement member that restricts relative rotation between the anvil and the lock ring, and a planar shape formed on a part of the outer peripheral surface of the anvil. A notch portion is configured to include a relief surface, a notch is formed at a position facing the relief surface of the carrier member, and the engagement member is held by the notch. The carrier member has a basic cylindrical shape having an inner diameter slightly larger than the outer diameter of the cylindrical portion of the anvil, and the cutout portions are formed at a plurality of locations on the carrier member. The engaging members are cylindrical members that are arranged one by one in the notch portions, and are arranged so that the axial direction thereof is parallel to the axial direction of the output shaft.

  According to another feature of the invention, when the anvil is rotated relative to the housing while the hammer is stopped rotating, the relative rotation between the anvil and the lock ring is limited. When the relative rotation angle between the carrier member and the anvil becomes larger than a predetermined angle and the center position of the relief surface is separated from the engagement member, the engagement member is sandwiched between the outer peripheral surface of the anvil and the inner peripheral surface of the lock ring. This limits the relative rotation of the anvil to the lock ring. The carrier member has a third protrusion that extends in a radial direction from the cylindrical portion and protrudes so as to face the second protrusion of the anvil, and the third protrusion is the rotation of the hammer when the drive source rotates. The carrier member is slightly moved with respect to the anvil by abutting with the first protrusion, and the engagement member comes into contact with the moved carrier member so that the engagement member is positioned at the center of the relief surface. Retained.

According to still another feature of the present invention, the notch portions are notched in a concave shape in the axially rearward direction from the front side opening of the cylindrical portion, and are provided at two locations on the circumferential diagonal line, A second notch for accommodating the second protrusion of the anvil is formed in the rear opening of the cylindrical portion at a position 90 degrees apart from the notch as viewed in the circumferential direction. Is a shape protruding in the radial direction from the circumferential edge of the second notch .

According to the first aspect of the present invention, when the hammer rotates, the lock mechanism is configured to unlock the lock mechanism by contacting the lock release member before the hammer contacts the anvil, and the lock release member is in a state where the hammer is in contact with the anvil. Is configured to be rotatable between the hammer and the anvil. When the hammer rotates, the lock mechanism is first unlocked and the anvil can be rotated. Further, the hammer's striking force is transmitted directly to the anvil without going through the unlocking member, so that the hammer's striking force is efficiently transmitted even if the rigidity of the unlocking member is low.
According to the invention of claim 2, when the hammer rotates, the first protrusion comes into contact with the unlocking member before coming into contact with the second protrusion, and the lock mechanism is unlocked. Since the protrusion is provided with a recess for receiving a part of the unlocking member, when the hammer rotates, the lock mechanism is first unlocked and the anvil can be rotated. In addition, when the concave portion for receiving the unlocking member is provided in the second protrusion on the anvil side, the rigidity of the anvil is reduced from the second protrusion to the shaft portion on the radially inner side. On the other hand, since the concave portion is provided in the first protrusion on the hammer side, a decrease in the rigidity of the anvil is suppressed, and the hammering force is transmitted efficiently.
According to the third aspect of the present invention, the carrier member that is coaxially rotated relative to the anvil by a small angle is provided, the flat relief surface is formed on a part of the outer peripheral surface of the anvil, and the notch of the carrier member is formed. Since the engaging member that restricts the relative rotation between the anvil and the lock ring is provided in the portion, the output shaft locking mechanism can be realized with a simple configuration. Further, the output shaft locking mechanism can be realized without changing the conventional basic structure of the anvil and the output shaft, and the torque can be efficiently transmitted to the tip tool. Further, when manual retightening is performed after performing a tightening operation with a tightening tool, the tightening tool can be used.

According to the invention of claim 4, the engaging members are columnar members arranged one by one in the notch, and are arranged so that the axial direction thereof is parallel to the axial direction of the output shaft. Therefore, a relatively large engagement area can be secured, and the rotation of the anvil can be firmly locked with respect to the housing.
According to the invention of claim 5, when the anvil is rotated with respect to the housing while the rotation of the hammer is stopped, the relative rotation between the anvil and the lock ring is restricted, so that a special operation for locking the output shaft is performed. A highly reliable tightening tool which is unnecessary and has extremely high operability and does not cause malfunction.
According to the invention of claim 6, since the relative rotation angle between the carrier member and the anvil is larger than a predetermined angle and the center position of the relief surface is separated from the engaging member, the operator is in a locked state. The output shaft can be locked easily by slightly rotating the housing body while pressing the tool against the fastening material.
According to the seventh aspect of the present invention, since the engaging member is held so as to be positioned at the center of the relief surface when the driving member rotates, the engaging member comes into contact with the moved carrier member. The output shaft becomes free and can idle, and normal tightening work by the drive source can be performed without any trouble.
According to the invention of claim 8, since the projecting portion has a shape projecting in the radial direction from the circumferential edge of the second notch, the carrier member can be easily attached to the anvil using the hammering surface. In addition, it is not necessary to increase the distance between the anvil and the lock ring in order to arrange the carrier member, and the output shaft locking mechanism can be realized without reducing the mounting efficiency .

  The above and other objects and novel features of the present invention will become apparent from the following description and drawings.

It is a longitudinal section showing the whole impact tool 1 concerning the example of the present invention. FIG. 2 is an exploded perspective view of the vicinity of a hitting part in FIG. 1. FIG. 2 is an enlarged cross-sectional view in the vicinity of a hitting portion in FIG. 1. FIG. 2 is an assembled perspective view in the vicinity of a hitting portion in FIG. 1. It is the elements on larger scale which show the shape of the hammer which concerns on the Example of this invention, a carrier, and an anvil. It is a figure which shows the state at the time of driving the impact tool 1 which concerns on the Example of this invention, and performing a fastening operation | work. FIG. 5 is a diagram for explaining the positional relationship between the anvil 20 and the engagement pin 37 at the AA cross-sectional position in FIG. 4. It is a figure which shows the state at the time of performing a hand-tightening operation | work at the time of the stop of the impact tool 1 which concerns on the Example of this invention. It is an expanded sectional view near a hitting part concerning the 2nd example of the present invention.

  Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, the same portions are denoted by the same reference numerals, and repeated description is omitted. Further, in the present specification, description will be made assuming that the front and rear directions and the up and down directions are directions shown in the drawing. FIG. 1 is a sectional view showing an entire impact tool 1 which is an example of a tightening tool according to an embodiment of the present invention.

  The impact tool 1 uses the electric power supplied from the battery pack 50 to rotate the motor 4 as a drive source. The battery pack 50 has a substantially cylindrical shape that can be attached to and detached from the internal space from the opening 3a at the end of the battery housing 3, and is configured in a so-called cassette type. The battery pack 50 is formed with two hook portions 51a, and holds the battery pack 50 by engaging with a recess (not shown) formed on the inner wall of the battery housing 3. To remove the battery pack 50, the battery pack 50 is pulled out from the opening 3a while pushing the latch 51. For example, three 14500-size lithium ion battery cells (not shown) are accommodated in the battery pack 50, and the rated voltage is DC 10.8V. The shape of the rear end portion (lower side in the figure) of the battery pack 50 is formed so as to cover the opening 3 a of the battery housing 3. A substrate 54 is provided at the other end of the mounting space of the battery pack 50 following the opening 3a, and a plurality of terminals 52 are provided so as to extend from the substrate 54 toward the opening 3a. A plurality of terminals 53 are provided at the front end portion (upper side in the drawing) of the battery pack 50, and the terminals 53 come into contact with the terminals 52 formed on the substrate 54 side when the battery pack 50 is attached to the battery housing 3.

  The rotation of the motor 4 is decelerated by the speed reduction mechanism 10 and transmitted to the spindle 28, and the spindle 28 is rotationally driven at a predetermined speed. The housing of the impact tool 1 includes a motor housing 2 and a battery housing 3. The motor housing 2 and the battery housing 3 can be rotated about 70 degrees about the rotation shaft 8, and FIG. 1 shows a state in which the motor housing 2 and the battery housing 3 are rotated. When the output shaft locking mechanism described later is operated and the fastening member is manually tightened or loosened using the main body of the impact tool 1, the battery housing 3 is rotated in the state as shown in FIG. preferable. Although not shown, the battery housing 3 can be rotated so as to be arranged coaxially with the spindle 28 and the rotating shaft 4a of the motor. The motor housing 2 can be divided into left and right parts by molding a synthetic resin such as plastic, and the left and right parts are fixed by screws (not shown). In the tightening tool of the present embodiment, the impact mechanism 19 and the speed reduction mechanism 10 are directly accommodated in the motor housing 2 made of synthetic resin, but these are substantially cup-shaped cases formed by integral molding of metal ( The case may be housed in a hammer case and connected to the motor housing.

  The impact tool 1 is provided with a trigger switch 7 for controlling on / off of rotation of the motor 4. The trigger switch 7 can be turned on or off by the operator pulling the trigger operation unit 6. In this embodiment, the trigger switch 7 is an on / off changeover switch. However, the trigger switch 7 may be configured as a variable switch so as to adjust the rotation speed of the motor 4 in accordance with the pulling amount of the trigger operation unit 6. The rotation changeover switch 9 is a switch for switching the rotation direction of the motor 4 and can switch the rotation direction of the output shaft 18 to the forward direction (tightening direction) or the reverse direction (relaxation direction).

  The speed reduction mechanism 10 has a plurality of planetary gears 12 to which the rotating shaft 4a of the motor 4 is connected to the sun gear 11, and the planetary gears 12 rotate while rotating with the internal gear 13 located on the outer peripheral side thereof. Revolve around the sun gear 11. The spindle 28 is a member for rotating the hammer 22, and the rear end side of the spindle 28 is connected to the rotation shafts of a plurality of planetary gears and functions as a planet carrier. As a result, the revolution movement of the planetary gear 12 is converted into the rotation movement of the spindle 28. The spindle 28 is connected to the hammer 22 by a cam mechanism. The cam mechanism includes a V-shaped cam groove 26 formed on the outer peripheral surface of the spindle 28 and a hammer cam groove 24 formed on the inner peripheral surface of the hammer 22. The steel balls 25 are engaged with these cam grooves.

  The hammer 22 is always urged forward by a spring 27, and when stationary, the hammer 22 is in a position spaced from the end face of the striking arm 21 by the engagement of the steel ball 25 and the cam grooves 24, 26. And the hammer nail | claw 23 and the striking arm 21 which are protrusion parts are formed symmetrically in two places on the rotation plane where the hammer 22 and the anvil 20 face each other. When the spindle 28 is driven to rotate, the rotation is transmitted to the hammer 22 via the cam mechanism, and the hammer claw 23 of the hammer 22 engages with the striking arm 21 of the anvil 20 before the hammer 22 rotates halfway. When the anvil 20 is rotated, when relative rotation occurs between the spindle 28 and the hammer 22 due to the reaction force of engagement at that time, the hammer 22 compresses the spring 27 along the cam groove 26 of the cam mechanism, and the motor 4. Start retreating to the side.

  When the hammer claw 23 gets over the striking arm 21 by the backward movement of the hammer 22 and the engagement between the two is released, the hammer 22 adds the elastic energy accumulated in the spring 27 and the cam mechanism in addition to the rotational force of the spindle 28. The anvil 20 is rotated by the urging force of the spring 27 while the hammer claw 23 strikes the striking arm 21 swiftly while rapidly accelerating in the direction of rotation and forward. The output shaft 18 is connected to the front side of the anvil 20, and the rotational impact force is transmitted to the screw via a tip tool 48 mounted in the mounting hole of the output shaft 18. Thereafter, the same rotation and striking operations are repeated, and for example, a fastening member such as a screw is screwed into a material to be fastened such as wood. In this embodiment, since the output shaft 18 and the anvil 20 are manufactured by integral molding, it is possible to realize an impact tool that has no backlash between them and has high rigidity and quiet impact sound.

  FIG. 2 is an exploded perspective view showing an assembly structure in the vicinity of the striking portion of FIG. In this embodiment, a structure of an anvil 20 used in a conventional mechanical impact mechanism and a lock ring 38 that pivotally supports an output shaft 18 formed integrally with the anvil 20 on the motor housing 2. A locking mechanism for locking the relative rotation of the anvil 20 with respect to the motor housing 2 (lock ring 38) is provided. The lock mechanism mainly includes a relief surface 20a formed on a part of the anvil 20, a lock ring 38, and two engagement pins 37. In this embodiment, the lock mechanism is for releasing the lock state. A carrier 33 was provided as an unlocking member. The carrier 33 is interposed between the lock ring 38 and the anvil 20. The shape of the hammer 22 and a part of the shape of the anvil 20 were changed in accordance with the addition of the carrier 33 and the two engagement pins 37. The hammer 22 is manufactured by integrally molding metal so as to have a predetermined mass, and is connected to the spindle 28 by a cam mechanism. On the front side of the hammer 22, hammer claws 23 (first protrusions) are formed at two locations in the circumferential direction. The hammer claw 23 is a projection that becomes a striking surface for striking the striking arm 21 and projects to extend forward, and the striking surface 23a in the forward rotation direction and the striking surface in the reverse rotation direction on both circumferential surfaces thereof. 23b is formed. Here, in the present specification, the forward rotation direction is, for example, a direction in which a screw or bolt is tightened, and the reverse rotation direction is described as a direction in which the screw or bolt is loosened. The hammer claw 23 of the present embodiment is further provided with a striking surface 23c which is a second striking surface formed on the inner peripheral side of the striking surface 23a. Similarly, a striking surface 23d is formed on the inner peripheral side of the striking surface 23b. Is formed. The second striking surface is a recessed portion that is recessed with respect to the circumferential striking direction with respect to the first striking surface.

  The anvil 20 is a member that is hit by the hammer 22, and in this embodiment, the output shaft 18 is connected to the distal end side of the anvil 20, and these are manufactured by integral molding. In FIG. 2, the output shaft 18 is a schematic view, and illustration of a mounting hole in which the tip tool 48 is mounted and a through hole formed in the radial direction for inserting the ball 43 is omitted. As for the shape of the anvil 20, two striking arms 21 (second protrusions) extending in the radial direction from the cylindrical main body member are formed. The striking arm 21 is formed at a position separated by 180 degrees in rotation angle, and is provided to extend radially outward so as to engage with the hammer claw 23 (first protrusion). The striking arm 21 has a quadrangular pillar shape extending from the anvil 20 due to the nature of a striking member. However, the striking arm 21 is not limited to this shape, and may have a cylindrical basic shape as long as it has sufficient strength and durability. It may be a simple shape. It is important that the hitting arm 21 is formed with two flat hitting surfaces, one side in the circumferential direction becomes the hitting surface 21a in the forward direction, and the other one side in the circumferential direction is hit in the opposite direction It becomes the surface 21b. A relief surface 20a is formed in two portions of the main body portion of the anvil 20 that are separated by 180 degrees and part of which is scraped off in a flat shape.

A lock ring 38 is provided from the front side of the output shaft 18. The main function of the lock ring 38 is to rotatably support the output shaft 18, and a sliding bearing such as metal is integrally formed on the inner peripheral surface of the lock ring 38. Cubic screw bosses 38b are formed at two locations 180 degrees apart in the radial direction of the lock ring 38, and screw holes 38c are formed on the left and right side surfaces of the screw boss 38b. In this embodiment, the output shaft 18 is fixed to the motor housing 2 by using a lock ring 38 instead of using a cup-shaped hammer cover that covers the entire impact mechanism 19. Since the motor housing 2 is divided into two parts on the left and right, the output shaft 18 is supported by fixing the lock ring 38 using a screw (not shown) from the outside of the motor housing 2, and the left and right motor housings are also supported. 2 are joined.

  The carrier 33 functions as an unlocking member, has a basic shape of a cylinder, is coaxial with the anvil 20, and is disposed on the radially outer side of the anvil 20. The carrier 33 is not fixed to the anvil 20 but is attached to the anvil 20 so as to be relatively movable (rotated) by a small angle on the same axis. The carrier 33 has a cylindrical portion having an inner diameter (however, a necessary gap capable of relative rotation by a minute angle is ensured) substantially equal to the outer diameter of the cylindrical portion of the anvil 20, and a diagonal position of the rear portion of the cylindrical portion. Two recesses (second cutouts) 33a are formed in the recesses, and claw portions (third projections 34) projecting radially from both circumferential edges (both ends) of the recesses 33a are formed. . The interval between both ends in the circumferential direction of the recess 33 a is configured to be slightly wider than the radial width of the striking arm 21. In this embodiment, two striking arms 21 are formed on the outer side from a position 180 degrees apart from the columnar portion of the anvil 20, so that four protrusions 34 are formed at positions facing each hit surface. The protrusion 34 is a portion that is contacted by the additional striking surfaces 23c and 23d that are additionally formed on the hammer 22, and changes the relative position of the carrier 33 with respect to the anvil 20 by hitting the striking surfaces 23c and 23d. (However, the rotation angle is about ± 10 degrees). A cutout portion 33 b is formed at a position facing the escape surface 20 a of the carrier 33. The notch 33b is for defining a space for accommodating the engaging pin 37. The inner peripheral side of the notch is covered by the relief surface 20a of the anvil 20, and the outer peripheral side of the notch 33b is locked. Covered by the cylindrical portion 38d of the ring 38, the front side of the cutout portion 33b is covered by a stepped portion 38e of the lock ring 38, and the rear side and both ends in the radial direction are covered by the wall portion of the cutout portion 33b. In this way, the engagement pin 37 rolls (revolves) substantially in synchronism with the anvil 20 within the space defined by the notch 33b. The engagement pin 37 acts as a lock mechanism that restricts the relative rotation of the anvil 20 and the lock ring 38 when the relative position between the anvil 20 and the carrier 33 is slightly shifted in the radial direction. The details of this action will be described later. To do.

FIG. 3 is an enlarged cross-sectional view of the vicinity of the hitting portion of FIG. As can be understood from FIG. 3, the carrier 33 is disposed on the front end side of the hammer 22 so that the rear end portion of the hammering arm 21 is the same. The front end portion of the carrier 33 is held at the front end side by the step portion 38 e of the lock ring 38, the outer peripheral side is held by the cylindrical portion 38 d, and the inner peripheral side is held by the outer peripheral surface of the anvil 20. A cylindrical fitting hole 28 a is formed near the center of the rear end side of the anvil 20, and a fitting shaft 20 b formed at the tip of the spindle 28 is accommodated in the hole. Thus since the front end portion of the rear end and the spindle 28 of the anvil 20 is pivotally supported so as to be relatively rotated, rigidity can be achieved with high hitting portion. The lock ring 38 has a cylindrical basic shape, but the shaft of the engagement pin 37 is prevented so that the frictional resistance between the lock ring 38 that is a rotated member (fixed member) and the engagement pin 37 that is a revolving member does not increase. It is preferable to form a minute contact region (such as a convex portion) at the tip in the direction. An O-ring 39 is attached to the bearing portion 38a of the lock ring 38 so that grease does not leak from the striking mechanism portion. A mounting hole 18 a having a hexagonal cross-sectional shape perpendicular to the axial direction for inserting the tip tool 48 is formed at the tip of the output shaft 18. A tip tool mounting portion 40 is provided on the tip side of the output shaft 18. A through hole 18b for movably accommodating the ball 43 is formed on the side surface of the output shaft 18, and the shape is formed so that the ball 43 does not fall out from the through hole 18b to the inner peripheral side. The radially outer side of the ball 43 is held by a sleeve 41 urged by a spring 44. The front side of the spring 44 is fixed by a washer 42, and the washer 42 is held by a C ring 45 so as not to move in the axial direction. The tip tool 48 can be attached to or removed from the output shaft 18 by moving the sleeve 41 forward in the axial direction against the urging force of the spring 44 from the steady position shown in FIG. When the sleeve 41 is moved forward, the contact state between the outer peripheral portion of the ball 43 and the convex surface formed on the inner peripheral side of the sleeve 41 is released, and the ball 43 can move slightly outward in the radial direction. 48 can be mounted and removed without resistance. An LED 47 for irradiating the tip tool direction is provided on a part of the motor housing 2 and below the output shaft 18. Electric power is supplied to the LED 47 via the power line 49.

  FIG. 4 is a perspective view after assembly in the vicinity of the striking portion of FIG. The state where the motor housing 2 is not attached is shown so that the positional relationship can be understood. Thus, at the time of assembly, the carrier 33 cannot be seen when viewed from an oblique direction as shown in the figure, and has substantially the same shape as a conventional impact tool. However, in the present embodiment, the use of the carrier 33 and the two engagement pins 37 enables a specific operation. In the subsequent drawings, the operation of the impact tool 1 according to the present embodiment will be described using the cross-sectional view of the AA portion and the cross-sectional view of the BB portion. Here, the cross section of the AA portion is a plane passing through the two screw holes 38c provided in the left-right direction of the lock ring 38, and is a cross section perpendicular to the axial direction. The cross section of the B-B portion is a plane that passes through the axial centers of the hammer claw 23 and the striking arm 21 and is a cross section perpendicular to the axial direction.

  FIG. 5 is a partial enlarged cross-sectional view showing the shape of the hammer and carrier according to the embodiment of the present invention, and is a cross-sectional view taken along the line BB in FIG. Two hammer claws 23 arranged diagonally in the circumferential direction have two striking surfaces 23c and 23d added to the inner peripheral side in addition to the two striking surfaces 23a and 23b located on the outer peripheral side in the elliptical circumferential direction. It is made into the shape which was done. Here, the striking surfaces 23a and 23b are formed to strike the striking surfaces 21a and 21b, and these have the same functions as the hammer claws used in the conventional impact tool, and the basic shape is also It is almost equivalent. The striking surfaces 23c and 23d are for pressing the projection 34 of the carrier 33. Here, as can be seen from the positional relationship in FIG. 5, when the hammer 22 rotates when tightening the screw (counterclockwise in FIG. 5), the striking surface 23 c of the hammer claw 23 first hits the striking surface 34 a of the protrusion 34. To touch. As described above, since the carrier 33 and the striking arm 21 can be moved relative to each other by a minute angle (about 20 degrees in rotation angle), the striking surface 23c pushes the striking surface 34a and does not strike. After that state, when the carrier 33 rotates counterclockwise by the rotation of the hammer 22, the striking surface 23 a of the hammer 22 collides with or engages the striking surface 21 a of the striking arm 21. In this collision, the reaction force of the fastening member is transmitted from the tip tool 48 to the output shaft 18 configured integrally with the anvil 20, so this collision is a strong hit. FIG. 5 shows the state at the moment when the striking surface 23a and the striking surface 21a are engaged. At this time, a predetermined interval is generated between the projection 34 and the striking arm 21. Shaped. That is, the distance between the hitting surface 21a of the hitting arm 21 and the hitting surface 23c of the hammer claw 23 is a with respect to the thickness b in the rotation direction of the protrusion 34, and a <b. With this configuration, the carrier 33 contributes to torque transmission because the force of the hammer claw 23 directly acts on the striking arm 21 when a striking is performed or when the bolt or the like is rotated before being seated. Therefore, there is almost no adverse effect caused by interposing the carrier 33. In addition, since a strong striking force is not transmitted to the carrier 33, the impact transmitted to the carrier 33 can be reduced and the life can be extended.

  Next, a state when the impact tool 1 is driven to perform a tightening operation will be described with reference to FIG. 6 (1) to 6 (4) show the cross section of the AA section and the cross section of the BB section side by side, respectively. Here, the hammer 22 is driven by the motor 4. FIG. The hammer 22, the anvil 20, the carrier 33, and the components associated therewith are rotationally symmetric (two-fold symmetric) about the rotation center, and for convenience of illustration, only a part of the reference numerals are given. The carrier 33 sandwiches the striking arm 21 of the anvil 20 and provides a protrusion 34 so as to have a certain clearance from the hit surfaces 21a and 21b of the anvil 20, thereby limiting the rotation angle of the carrier 33 to a certain range. To do. 6 (1) is a view showing a state in which the hammer claw 23 is separated from the striking arm 21 (for example, a state when the rotation of the hammer 22 is started). The hammer 22 transmitted to the spindle 28 via the speed reduction mechanism 10 (see FIG. 1) and held by the cam mechanism rotates in the direction of the arrow 61. At this time, the position of the striking arm 21 (the rotation angle of the anvil 20) and the positional relationship between the protrusions 34 of the carrier 33 are as shown in the figure. The protrusion 34 and the striking arm 21 extending in the radial direction are stably held at positions where predetermined intervals 62 and 63 exist. As can be seen from FIG. 6 (1), the shaft portion (= output shaft 18) of the anvil 20 is housed inside the cylindrical portion of the carrier 33, and the engagement pins 37 are positioned in the inner space of the cutout portion 33b. To do. Here, the carrier 33 and the anvil 20 are merely fitted, and by setting their shapes, the carrier 33 and the anvil 20 can be rotated relative to each other by a minute angle.

FIG. 6 (2) is a diagram showing a state in which the rotation of the carrier 33 is started when the hammer 22 further rotates in the direction of the arrow 64 and the striking surface 23 c of the hammer claw 23 abuts against the striking surface 34 a of the protrusion 34. is there. When the hammer 22 is rotated by driving the motor, the hammer 22 comes into contact with the carrier 33 before the anvil 20 is struck by rotation, and the carrier 33 rotates. For this reason, the shape of the hammer claw 23 is set so that the striking surface 23 a is not in contact with the striking arm 21 when the striking surface 23 c comes into contact with the protrusion 34. When further rotated from this state, the hammer claw 23 rotates the carrier 33 in the direction of the arrow 65 and the striking surface 23a contacts the striking surface 21a of the striking arm 21 as shown in the right side of FIG. (Blows anvil 20). Here, as described with reference to FIG. 5, there is a gap in the portion of the thick line 67, so the carrier 33 does not hit the hitting arm 21. At this time, the gap indicated by the arrow 66 is larger than the gap indicated by the arrow 62 in (1). With such carrier 33 is rotated by a small angle with respect to the striking arm 21, the outer peripheral portion the circumferential direction of the edge portion of the notch 33b is engaging pins 37 of the carrier 33 as the left view of the results (3) The engagement pin 37 is pushed away to the vicinity of the center of the relief surface 20a provided on the peripheral surface of the anvil 20. The hammer 22 strikes the anvil 20 while rotating the carrier 33 and transmits the rotation to the tip shaft side. The anvil 20 rotates while the inner peripheral side of the engagement pin 37 is in contact with the relief surface 20a, but the contact portion (line parallel to the axial direction) remains at the approximate center in the circumferential direction of the relief surface 20a.

  FIG. 6 (4) is a diagram showing a state where the hammer 22 is further rotated from the state (3). In this state, the anvil 20 is rotated in such a manner that the striking surface 23a of the hammer claw 23 pushes the striking surface 21a of the striking arm 21 or strikes it strongly. At this time, the engaging pin 37 remains in contact with the edge portion of the notch 33 b of the carrier 33. For this reason, the rotating portion (anvil 20, carrier 33, engagement pin 37) does not strongly interfere with the inner wall of the non-rotating portion (lock ring 38), and the hammer 22 maintains the relative positional relationship of FIG. Allows continuous rotation. That is, it is possible to avoid the engagement pin 37 that has been vigorously rotated by the carrier 33 and collided with the lock ring 38 and the end of the relief surface 20a of the anvil 20. Furthermore, it is possible to prevent the hammer 22 from falling between the anvil 20 and the carrier 33 and to reliably rotate the carrier 33 before the anvil 20.

  FIG. 7 is a view for explaining the positional relationship between the anvil 20 and the engagement pin 37 at the AA cross-sectional position of FIG. As shown in FIG. 6 (4), when the hammer 22 is rotating, the anvil 20 is rotated so that the striking surface 23a of the hammer claw 23 pushes the striking surface 21a of the striking arm 21. The positional relationship of the engagement pin 37 is as shown in FIG. In this state, the engagement pin 37 is positioned substantially in the center in the vertical direction (circumferential direction) of the relief surface 20a. That is, when the vertical direction (circumferential direction) width of the relief surface 20a is 2c, the anvil 20 and the engagement pin 37 are arranged. The contact point 72 is located at a position c from the top and c from the bottom. In this situation, the farthest distance from the rotation center 71 to the outer peripheral surface of the engagement pin 37 is R1. R1 is (radius of the anvil 20−cutting amount of the relief surface 20a + diameter of the engaging pin 37). In the present embodiment, if the R1 is configured to be smaller than the inner diameter of the cylindrical portion 38d of the lock ring 38, the engagement pin 37 does not limit the rotation of the anvil 20 and the carrier 33.

  Next, the rotation of the motor 4 is stopped using FIG. 8, and the operator rotates the impact tool 1 itself with the tip tool 48 fitted to a screw head (not shown) so that the operator can perform the same operation as the driver. The state (hand-tightening work) when tightening a screw etc. is demonstrated. FIG. 8 (1) is a cross-sectional view showing a state (neutral position) immediately before the impact tool 1 itself is rotated, in which the cross section of the AA portion and the cross section of the BB portion are arranged side by side on the left and right, respectively. It is. In addition, since the hammer 22 does not act at all when the hand tightening operation is performed, the rotational position of the hammer 22 is not important, and the position of the hammer 22 shown in FIG. 8 is merely an example and does not have any particular meaning. . In FIG. 8 (1), the operator rotates the motor housing 2 for the hand tightening operation. By rotating the motor housing 2, the lock ring 38 rotates in the direction of the arrow 81. As a result, in the AA cross-sectional position, the striking arm 21 is in the same state as being relatively rotated by a small angle in the direction opposite to the arrow 81.

  Next, when the worker further rotates the impact tool 1 itself as shown in FIG. 8B, the hit surface 21 a of the hit arm 21 comes into contact with the protrusion 34. As a result, the relative positional relationship between the carrier 33 and the anvil 20 changes, and the relative positional relationship between the relief surface 20a formed on the anvil 20 and the engagement pin 37 also changes. FIG. 7B shows the change in the relative positional relationship. In FIG. 7B, when the anvil 20 rotates relatively as indicated by an arrow 73, the engaging pin 37 has the same positional relationship as being relatively moved in the direction of the arrow 74. However, it moves on the anvil 20 side, and the engagement pin 37 does not move. As a result, the position where the engagement pin 37 and the relief surface 20a come into contact moves from the contact point 72 in FIG. 7 (1) to the contact point 75 in FIG. 7 (2). As a result, the farthest distance from the rotation center 71 of the anvil 20 to the outer peripheral surface of the engagement pin 37 changes from R1 to R2 in (1). As can be understood from the figure, since R2 has a positional relationship of R1 <R2, when the inner diameter Rc of the lock ring 38 is set to have a relationship of R1 <Rc <R2, as shown in (2) Due to the change in the relative positional relationship of the engagement pin 37, the engagement pin 37 bites between the lock ring 38 and the end portion of the relief surface 20a of the anvil 20, and the lock ring 38 and the anvil 20 are united to form an output shaft. Operates as a locking mechanism. In other words, when the operator rotates the impact tool 1 itself when not in operation, the rotation of the anvil 20 remains locked, so that the hand tightening operation can be performed effectively.

  In addition, not only is the impact tool 1 itself rotated to tighten a screw or the like, but the rotation of the anvil 20 is similarly locked even when it is loosened. FIG. 8 (3) shows this state, and the displacement of the relative positional relationship between the relief surface 20a formed on the anvil 20 and the engagement pin 37 is only in the reverse rotation direction as shown in FIG. 8 (2). The rotation of the anvil 20 is similarly locked. As described above, in the present embodiment, when the hand tightening operation is performed in which the motor 4 is stopped and the impact tool 1 itself is rotated, the anvil 20 seems to be unable to rotate with respect to the lock ring 38 due to the action of the lock ring 38. Since the output shaft locking function can be realized, even a tightening tool for impact tightening can easily perform hand tightening work. Moreover, when shifting from the tightening operation using the drive source to the manual tightening operation, no special operation such as operation of the operation lever by the operator is required, and the impact tool 1 itself can be simply rotated. This makes it possible to realize a very convenient tightening tool.

  When the next screw is tightened after the hand tightening operation is finished, the trigger operation portion 6 is pulled to rotate the motor 4. As shown in FIGS. 6 (1) to 6 (3), the hammer claw 23 is attached to the carrier 33. By pushing the projection 34, the relative position of the engagement pin 37 with respect to the anvil 20 returns to the position shown in FIG. 7 (1) and becomes free (unlocked). The conventional tightening operation can be performed without any influence.

  As described above, according to the impact tool 1 of the present embodiment, the anvil 20 and the output shaft 18 are manufactured in an integral structure, and the output shaft locking mechanism is realized by simply adding the carrier 33 and the engagement pin 37. The shape can be simplified and the hammering energy of the hammer 22 can be efficiently transmitted to the tip tool 48. In particular, since it is not necessary to provide a joint portion with the anvil 20 and the output shaft 18 as a divided structure, there is an impact sound when the rotation is transmitted from the hit surface 21a, 21b of the anvil 20 to the output shaft 18 when the hammer 22 is hit. Vibration can be greatly reduced. Furthermore, since the impact tool 1 can be bent around the rotation shaft 8, it is possible to apply a high torque when performing a tightening operation by rotating the main body.

  Further, when the lock ring 38 and the output shaft 18 are fixed in order to be tightened by the motor 4 and rotated in the tightening direction (the direction opposite to the hand tightening direction), the hammer 22 is rotated to the carrier 33. Since the housing 2b and the output shaft 18 can be idled by merely making contact with each other, it is not necessary to switch between the manual tightening operation using the output shaft lock and the tightening operation by the motor 4. As described above, in this embodiment, after the tightening is completed and the motor 4 is stopped without operating the output shaft lock switch or the like, the impact tool 1 main body is rotated in the tightening direction of the fastening member. Retightening and tightening confirmation can be performed.

  Next, a second embodiment of the present invention will be described with reference to FIG. The same components as those in the first embodiment are denoted by the same reference numerals, and the configuration and the operation thereof are the same, so that repeated description is omitted. The difference from the first embodiment is that a ball bearing 141 is used instead of metal to support the output shaft 118. The shape of the lock ring 138 has also been changed according to the shape, but the change is only in the vicinity of the tip, and the shape of the cylindrical portion 138d that holds the engaging pin 37, the screw boss portion and the screw hole (not shown) The size and shape are the same as the shape of the lock ring 38 shown in FIG. Further, the shape of the tip of the motor housing 102 is slightly changed to a shape for holding the ball bearing 141. Further, with respect to the output shaft 118, a groove 118c continuous in the circumferential direction was formed in order to prevent the ball bearing 141 from slipping forward in the axial direction, and a retaining ring 142 was attached thereto. By supporting the output shaft 118 with the ball bearing 141 as in the second embodiment, an impact tool having high rigidity and capable of rotating smoothly can be realized.

  As mentioned above, although this invention was demonstrated based on the Example, this invention is not limited to the above-mentioned Example, A various change is possible within the range which does not deviate from the meaning. For example, in the above-described embodiment, a mechanical impact tool is used as an example of a tightening tool, but the present invention can be similarly applied to an oil pulse impact tool. Furthermore, the present invention is not limited to impact tools, and can be applied to driver drills as well.

DESCRIPTION OF SYMBOLS 1 Impact tool 2 Motor housing 2b Housing 3 Battery housing 3a Opening 4 Motor 4a Rotating shaft 6 Trigger operation part 7 Trigger switch 8 Rotating shaft 9 Rotation changeover switch 10 Reduction mechanism 11 Sun gear 12 Planetary gear 13 Internal gear 18 Output shaft 18a Mounting hole 18b Through-hole 19 Impact mechanism 20 Anvil 20a Escape surface 20b Fitting shaft 21 Strike arm (second projection) 21a, 21b Struck surface 22 Hammer 23 Hammer claw (first projection)
23a, 23b Stroke surface (first striking surface)
23c, 23d Striking surface (second striking surface)
24 Hammer cam groove 25 Steel ball 26 Cam groove 27 Spring 28 Spindle 28b (Spindle) fitting hole 33 Carrier 33a Recess 33b Notch 34 Protrusion (third protrusion)
34a Impact surface 37 Engagement pin 38 Lock ring 38a Bearing portion 38b Screw boss 38c Screw hole 38d Cylindrical portion (bearing surface) 38e Stepped portion 39 O-ring 40 Mounting portion 41 Sleeve 42 Washer 43 Ball 44 Spring 45 Ring 47 LED
48 Tip tool 49 Power line 50 Battery pack 51 Latch 51a Hook 52 Terminal 53 Terminal 54 Board 71 Center of rotation 72, 73, 75 Contact point 102 Motor housing 118 Output shaft 118c Groove 138 Lock ring 138d Cylindrical part 141 Ball bearing 142 Stop ring

Claims (8)

A housing that houses the drive source;
A hammer driven in a rotational direction by the drive source;
An anvil attached with a tip tool and driven in the direction of rotation in contact with the hammer;
A lock mechanism for switching whether to lock relative rotation of the anvil with respect to the housing;
In a tightening tool having
Provided rotatably unlocking member relative to said anvil, configured such that the hammer is to unlock the lock release member and contact touch to the locking mechanism before said a rotating hammer is in contact with said anvil ,
A tightening tool, wherein the unlocking member is configured to be rotatable between the hammer and the anvil while the hammer is in contact with the anvil. A housing that houses the drive source;
A hammer driven in the rotational direction by the drive source and having a first protrusion extending forward;
A shaft that is rotatable relative to the housing and to which a tip tool is attached ; and an anvil having a second protrusion that extends radially outward from the shaft so as to contact the first protrusion;
A lock mechanism for switching whether to lock relative rotation of the anvil with respect to the housing;
In the tightening tool with
An unlocking member is rotatably provided with respect to the anvil, and when the hammer rotates, the first protrusion comes into contact with the unlocking member before coming into contact with the second protrusion, and the lock mechanism Configure to unlock,
A tightening tool comprising a recess for receiving a part of the unlocking member in the first protrusion. A drive source, a hammer rotated by the drive source, and
An anvil rotated in contact with the hammer;
Comprises a housing that accommodates these, and in fastening the tool to rotate the output shaft connected to the tool bit that is attached to the anvil,
The anvil and the output shaft are integrally formed,
A cylindrical carrier member that is attached so as to be relatively rotatable by a small angle on the same axis with respect to the anvil, and penetrates the output shaft;
A lock ring is provided for restricting movement of the carrier member toward the output shaft;
Forming a flat relief surface on a part of the outer peripheral surface of the anvil;
Forming a notch at a position facing the relief surface of the carrier member;
A tightening tool, wherein an engagement member for restricting relative rotation between the anvil and the lock ring is provided in the notch. The carrier member is a cylindrical basic shape having an inner diameter slightly larger than the outer diameter of the cylindrical portion of the anvil,
The notch is formed at a plurality of locations on the carrier member,
The engaging member is a cylindrical member disposed one by one in the notch, and is arranged so that an axial direction thereof is parallel to an axial direction of the output shaft. Item 4. The tightening tool according to item 3.   The fastening tool according to claim 4, wherein when the anvil is rotated with respect to the housing while the hammer is stopped rotating, the engaging member restricts relative rotation between the anvil and the lock ring. .   When the relative rotation angle between the carrier member and the anvil is larger than a predetermined angle and the center position of the relief surface is separated from the engagement member, the engagement member is connected to the outer peripheral surface of the anvil and the lock ring. The clamping tool according to claim 5, wherein relative rotation of the anvil with respect to the lock ring is limited by being sandwiched between inner peripheral surfaces of the anvil. The carrier member has a third protrusion that extends in a radial direction from the cylindrical portion and protrudes so as to face the second protrusion of the anvil.
The third protrusion is in contact with the first protrusion of the hammer during rotation of the drive source, thereby slightly moving the carrier member relative to the anvil,
The said engaging member is hold | maintained so that it may be located in the center of the said escape surface by the said engaging member contacting with the said carrier member to be moved. The tightening tool described. The notch portions are notched in a concave shape in the axially rearward direction from the opening on the front side of the cylindrical portion, and are provided at two locations on the diagonal in the circumferential direction.
In the opening on the rear side of the cylindrical portion, a second notch for receiving the second protrusion of the anvil is formed at a position 90 degrees apart from the notch as viewed in the circumferential direction,
The fastening tool according to claim 7, wherein the third protrusion has a shape protruding in a radial direction from a circumferential edge of the second notch.

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