JP6260229B2 - Impact tools - Google Patents

Description

  The present invention relates to an impact tool that converts rotation of a drive source such as a motor into a rotational impact force and transmits the rotation impact force to a tip tool.

  Hand-held impact tools, particularly cordless impact tools that are driven by electrical energy stored in a battery, are widely used. In an impact tool such as an impact driver, as disclosed in Patent Document 1, for example, a spindle that is rotated by a drive source such as a motor and a shaft that is coaxially supported via a metal in front of the spindle, such as a bit or a socket Equipped with an anvil with a tip tool mounting hole formed at the front end and a striking mechanism that transmits the rotation of the spindle to the anvil as a rotational striking force. It is possible. In recent years, the motor power of impact tools has been gradually improved due to improvements in motor technology, battery output, and the like. As a result, there are concerns about breakage and breakage of the tip tool.

JP 2008-278633 A

  When the tip tool breaks or breaks for some reason in the impact tool, the work can be continued by pulling out the tip tool mounted from the mounting hole and replacing it with another tip tool. As for the form of breakage of the accessory tool, the tip part (thread) of the accessory tool is damaged, the accessory tool breaks, or the accessory tool sticks to the mounting hole, and it can be bitten by another expression. It may become. The phenomenon of “galling” is, for example, a state in which a part of the tip tool is fitted to such a degree that it is deformed by an output shaft having a mounting hole that is rigid in material and cannot be removed from the mounting hole with normal force. Point to. An example of this state is shown in FIG. FIG. 11A is a cross-sectional view showing an engaged state between the anvil (output shaft) 136 and the tip tool 50 in a normal state. There is a slight gap between the outer surface of the tip tool 50 and the inner wall of the mounting hole 136a. The gap is for allowing the tip tool to be inserted and removed, and for the sake of clarity, the gap is illustrated to be large in the drawing. By holding the tip tool 50 and the anvil 136 in such a state, a tightening operation using an impact tool can be performed.

  Here, for some reason, the tip tool 50 may rotate relative to the anvil 136 beyond the allowable range as in (2). Since the tip tool 50 and the mounting hole 136a are formed so as not to be able to rotate relative to each other as shown in (2), the soft side material is mainly deformed (plastically deformed) in the state (2). ing. In a general electric tool, when the material of the output shaft and the material of the tip tool are compared, the output shaft side is harder, so that the tip tool 50 side is deformed more. FIG. 11 (3) shows this state, and (3) is a partially enlarged view of the F portion in (2). The rotational striking force is transmitted to the anvil 36, the tip tool 50, a screw (not shown), and the like, but a twisting force is applied to the anvil 36 and the tip tool 50. At this time, since the stress is generated in the tip tool 50 more than the anvil 36 in which the tip tool 50 can be inserted inside, the tip tool 50 is damaged earlier. However, the tip tool 50 damaged by the rotational impact force is damaged. The anvil 36 may bite into the tip tool mounting hole. In the state of (2), the corner portion of the tip tool 50 and the corner portion of the mounting hole 136a are displaced, the corner portion of the tip tool 50 reaches the flat portion of the inner wall of the mounting hole 136a, and the corner portion of the tip tool 50 is reached. Will be deformed. In other words, the tip tool 50 that should originally be at the virtually described outer edge position 151b is deformed like the outer edge portion 151a by deformation of each other, and this state is referred to as a “biting state” in this specification. expressing. In order to facilitate understanding, in FIG. 11 (3), both the tip tool 50 and the anvil 136 are shown as being deformed, but the degree of deformation depends greatly on the material of both.

  When such a galling phenomenon occurs in an impact tool, the tip tool 50 is fixed in a vise and held in a non-rotatable state, and the trigger (main body) of the impact tool is held so as not to rotate. Pull to rotate the motor. In this case, since the tip tool 50 cannot rotate with respect to the tool body, the impact mechanism performs a plurality of impacts immediately after the motor is started. When this impact is made, the impact is transmitted to the tip tool 50 via the output shaft, so that the state where the anvil 136 bites is eliminated, and the tip tool 50 can be taken out from the mounting hole 136a. By the way, there are an increasing number of cases where the broken tip tool remains in the tip tool mounting hole of the anvil and cannot be taken out. FIG. 10 shows this state. In FIG. 10, a galling state as shown in FIG. 11 (3) occurs between the tip tool 50 and the anvil 136, and the tip tool 50 is broken at the fracture surfaces 55a and 55b as shown by arrows 56. It shows a case where it has closed. In such a case, since the tip tool 50 remaining in the anvil 136 cannot be fixed with a vise, it is necessary to disassemble the main body and replace the anvil 136 together, which is difficult to maintain. There was a problem that replacement cost was required.

The present invention has been made in view of the above background, and an object thereof is to provide an impact tool that can easily take out a broken or broken tip tool that remains in an attachment hole of an anvil and cannot be taken out. is there.
Another object of the present invention is to provide an impact tool that does not require replacement of an anvil when it breaks that remains in the mounting hole of the anvil and cannot be removed.
Still another object of the present invention is to provide an impact tool which can apply an impact to the output shaft by preventing the rotation of the anvil or the output shaft from the outside of the tool body.

Of the inventions disclosed in the present application, typical features will be described as follows.
According to one aspect of the present invention, a driving source such as a motor, a hammering mechanism including a hammer and an anvil that is directly rotated by a driving source with or without a speed reduction mechanism, and a hammer case that houses the hammering mechanism, , And a mounting hole for mounting the tip tool is formed on the output shaft of the anvil . The output shaft is accommodated in the hammer case at the rear end side, and the front end side is exposed forward from the hammer case to mount the tip tool. In the impact tool in which the tip tool mounting portion for holding is formed, the mounting hole has a polygonal cross-sectional shape perpendicular to the axial direction, and an engagement portion for suppressing rotation of the output shaft from the outside of the hammer case is provided. , Provided in the portion of the output shaft exposed from the hammer case . The engaging portion is at least two or more opposing flat surfaces (portions where a part of the curved surface is chamfered) formed on the outer peripheral portion of the output shaft, or a plurality of concave or convex portions formed on the outer peripheral portion of the output shaft. Part. By providing the engaging portion in this way, a wrench or a dedicated tool can be attached to the outer peripheral portion of the output shaft, the rotation of the output shaft (anvil) can be prevented, and the output shaft can be prevented from rotating. The tip tool fixed in the mounting hole can be efficiently removed by striking.

  According to another feature of the present invention, the striking mechanism is formed by a hammer and an anvil hit by the hammer, the output shaft is manufactured integrally with the anvil, and the tip tool mounting portion is formed near the front end of the anvil. A guide sleeve is slidable in the axial direction with respect to the anvil. The engaging portion is provided on the anvil portion exposed when the guide sleeve is moved from the normal position or between the rear end of the guide sleeve and the front end of the hammer case that houses the striking mechanism, and is exposed to the outside. What is necessary is just to make it form in the part of an anvil.

  According to still another feature of the present invention, the output shaft and the guide sleeve are each provided with a rotation preventing portion for preventing relative rotation in the rotational direction, and the rotation of the output shaft can be prevented by preventing the rotation of the guide sleeve. Configured. In this way, the guide sleeve is configured not to rotate relative to the output shaft in the rotation direction (idle rotation). Therefore, the rotation of the output shaft is indirectly controlled by fixing the guide sleeve so that it cannot be rotated with a spanner or a vise. Can be blocked. According to this configuration, since it is not necessary to disassemble the tip tool mounting portion having the guide sleeve, the tip tool can be removed very easily during bite. The anti-rotation portion is formed on the output shaft and the guide sleeve and is at least one flat surface or an uneven portion that can be engaged with each other. When the outer peripheral portion of the guide sleeve is provided with at least two opposing flat portions, good.

  According to the present invention, a broken or broken tip tool that remains in the mounting hole of the anvil and cannot be taken out is subjected to a hammering operation of the anvil with a hammer in a state in which the rotation of the output shaft is prevented. While removing from the output shaft, the broken tip tool can be easily taken out. Moreover, since it is not necessary to replace the anvil even if the tip tool breaks in the mounting hole, an impact tool that is economical and easy to use can be realized.

It is a longitudinal cross-sectional view which shows the internal structure of the impact tool which concerns on the Example of this invention. It is a partial expanded sectional view which shows the impact mechanism 30 of FIG. 1, and a front-end tool mounting part vicinity. It is a side view which shows the single-piece | unit shape of the anvil 36 of FIG. It is sectional drawing of the AA part of FIG. It is a partial expanded sectional view which shows the impact mechanism and tip tool mounting part vicinity of the impact tool which concerns on the 2nd Example of this invention. It is sectional drawing of the BB part of FIG. It is a partial expanded sectional view which shows the impact mechanism and tip tool mounting part vicinity of the impact tool which concerns on the 3rd Example of this invention. It is sectional drawing of the CC part and DD part of FIG. It is a figure explaining the cross-sectional shape of the output shaft which concerns on the other Example of this invention. It is a figure for demonstrating the example which the tip tool 50 fractured | ruptured in the impact tool. (1) (2) is sectional drawing of the EE part of FIG. 10, Comprising: (3) is the elements on larger scale of the F part of (2).

  Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, the same components are denoted by the same reference numerals, and repeated description is omitted. Further, in this specification, description will be made assuming that the front, rear, left, right, and up and down directions are directions shown in the drawing.

  FIG. 1 is a diagram showing an internal structure of an impact tool 1 according to the present invention. The impact tool 1 uses the rechargeable battery 5 as a power source, drives the striking mechanism 30 using the motor 3 as a drive source, applies rotational force and striking force to the anvil 36 that is the output shaft, and holds it in the mounting hole 36a of the anvil 36. Rotating impact force is intermittently transmitted to a tip tool (not shown) such as a bit or socket to be tightened with a bolt, nut or screw. The impact tool 1 includes a housing 2 that is an outer frame forming an outer shape. The housing 2 has a substantially cylindrical body portion 2a extending in the front-rear direction, and extends substantially downward from the vicinity of the center in the axial direction (front-rear direction) of the body portion 2a, and has a substantially T-shape in side view. The handle portion 2b connected in this manner and the battery attachment portion 2c formed at the end of the handle portion 2b. A hammer case 4 for accommodating the striking mechanism 30 is provided on the front side of the body portion 2a. Here, the housing (broadly defined housing) of the impact tool 1 is configured by a housing 2 (narrowly defined housing) manufactured by a synthetic resin molded product such as plastic and a metal hammer case 4 such as aluminum alloy. Is done.

  The body 2a of the housing 2 accommodates a motor 3 as a driving source and a speed reducing mechanism 20 configured to reduce the rotation of the motor 3 and configured by a planetary gear. A striking mechanism 30 is accommodated that converts the rotation of the motor 3 decelerated by the speed reduction mechanism 20 into a rotational striking force and transmits it to the tip tool. The motor 3, the speed reduction mechanism 20, and the striking mechanism 30 are arranged on the same axis as the axis of the rotating shaft 3d of the motor 3, and the speed reduction mechanism 20 and the striking mechanism 30 are also arranged in series on the same axis. Be placed. The rotation shaft 3d of the motor 3 is rotatably held by a bearing 19a provided near the center of the body 2a of the housing 2 and a bearing 19b on the rear end side, and coaxially with the rotation shaft 3d at the front of the motor 3. A rotor fan 14 that is attached and rotates in synchronization with the motor 3 is provided, and an inverter circuit board 12 for driving the motor 3 is disposed behind the motor 3. The rotor 3a forms a magnetic path formed by the magnet 3c, and is constituted by, for example, a stack of thin metal plates in which four flat slots are formed. The rotor fan 14 is a so-called centrifugal fan that sucks air from the rear inner peripheral side and discharges it to the radially outer side on the front side, and includes a plurality of blades extending radially from the periphery of the through hole through which the rotary shaft 3d passes. Have. The air flow generated by the rotor fan 14 is taken into the housing 2 from the slots (not shown) formed in the housing portions around the air intake holes 17a and 17b and the inverter circuit board 12, and mainly the rotor 3a. An air discharge hole (not shown) formed in a housing portion around the rotor fan 14 that flows between the rotor 3 and the stator 3b, is sucked from behind the rotor fan 14 and flows in the radial direction of the rotor fan 14. To the outside of the housing 2. The inverter circuit board 12 is a circular board having substantially the same shape as the outer shape of the motor 3, and a plurality of switching elements 13 such as FETs and a rotational position detecting element 15 such as a Hall IC are mounted on the board.

  A trigger switch 7 is disposed in the upper part of the handle portion 2b, and a trigger 7a for operating the trigger switch 7 is provided in front of the trigger switch 7. Above the trigger 7a, a forward / reverse switching lever 8 for switching the rotation direction of the motor 3 to the forward direction or the reverse direction is provided. A control circuit board 9 having a function of controlling the speed of the motor 3 by the pulling operation of the trigger 7 a is accommodated in the lower part in the handle portion 2 b, and this control circuit board 9 is electrically connected to the battery 5 and the trigger switch 7. Connected. The control circuit board 9 is connected to the inverter circuit board 12 via the signal line 11. A battery 5 including a nickel-cadmium battery, a lithium ion battery, or the like is detachably mounted below the handle portion 2b. The battery 5 is a pack of a plurality of secondary batteries. When charging, the battery 5 is removed by removing the battery 5 from the impact tool 1 while pressing the release button 5a and mounting the battery 5 on a dedicated charger (not shown). . A control panel 10 is provided on the front upper surface of the battery mounting portion 2c. The control panel 10 is equipped with various operation buttons including setting of the number of rotations of the motor and a battery remaining amount display lamp. A belt hook 6 is attached to the right side or the left side of the battery attachment portion 2c. A light emitting means 48 such as an LED for irradiating the vicinity of the tip of the tip tool 50 is provided on the lower front side of the body portion 2a.

  The reduction mechanism 20 is a known planetary gear reduction mechanism that includes a sun gear, a ring gear, and a plurality of planetary gears. The spindle 31 also functions as a planet carrier that supports a plurality of planetary gears, and is rotatably supported via a bearing 18b. A hammer 33 is replaced on the spindle 31 so as to be movable in the front-rear direction, and the spindle 31 and the hammer 33 are connected by a cam mechanism. The cam mechanism for connecting the spindle 31 and the hammer 33 includes a pair of spindle cam grooves 31a formed on the outer peripheral surface of the spindle 31 obliquely with respect to the axial direction, and balls inserted into the pair of spindle cam grooves 31a. 32 and a hammer cam groove 33 a formed on the inner peripheral surface of the hammer 33. The anvil 36 is fitted to the inner periphery of the metal 18a and is rotatably supported. The hammer 33 is always urged forward (forward) by a spring 35. When the hammer 33 is at the most distal position, the hammer 32 engages with the ball 32 and the spindle cam groove 31a to engage the rear end surface of the anvil 36 with a predetermined amount. It is in a position with a gap. And the nail | claw part 34 is formed in two places on the rotation plane which the hammer 33 mutually opposes, the blade | wing part 37 which protrudes in the radial direction opposite from the rear-end part of the anvil 36 is formed, and the two nail | claw parts 34 are formed. Each is formed in a symmetrical position so that it can collide with two blade | wing parts 37 simultaneously.

  When the trigger switch 7 is pulled and the motor 3 is started, the motor 3 starts to rotate in the direction set by the forward / reverse switching lever 8, and the rotational force is decelerated by the speed reduction mechanism 20 and transmitted to the spindle 31. . When the spindle 31 is rotationally driven at a predetermined speed, the rotation of the spindle 31 is transmitted to the hammer 33 via the cam mechanism, and the claw portion 34 of the hammer 33 moves the blade of the anvil 36 before the hammer 33 is rotated halfway. The anvil 36 is rotated by engaging with the portion 37. When the tightening operation proceeds and the reaction force received by the hammer 33 from the anvil 36 increases, the hammer 33 starts to move backward toward the motor 3 while compressing the spring 35 along the spindle cam groove 31a of the cam mechanism. Relative rotation occurs between the hammer 33 and the spring 35. When the hammer 33 further moves backward, the claw portion 34 of the hammer 33 gets over the blade portion 37 of the anvil 36 and the engagement between the two is released. Then, the hammer 33 is rapidly accelerated in the rotational direction and forward by the elastic energy accumulated in the spring 35 and the action of the cam mechanism in addition to the rotational force of the spindle 31, while being forwardly driven by the biasing force of the spring 35, that is, It moves to the anvil 36 side, and the claw part 34 of the hammer 33 again engages (striates) with the blade part 37 of the anvil 36 and starts to rotate integrally. At this time, since a strong rotational impact force is applied to the anvil 36 via the blade portion 37, the rotational impact force is transmitted to a screw or the like (not shown) via the tip tool 50 attached to the anvil 36. Thereafter, the same operation is repeated, and the rotational impact force is intermittently and repeatedly transmitted from the tip tool 50 to the screw or the like, and the screw or bolt or the like is screwed into the fastening material (not shown).

  FIG. 2 is an enlarged cross-sectional view of the vicinity of the attachment portion of the tip tool 50 of FIG. At the front end of the spindle 31, a fitting shaft 31 b is formed to protrude forward and is connected to a fitting hole 36 b formed at the rear end of the anvil 36, and the anvil 36 is supported by the spindle 31 so as to be coaxially rotatable. The In this embodiment, the anvil 36 is formed integrally with the output shaft of the impact tool 1, and the front end thereof has a hexagonal cross section perpendicular to the axial direction (front-rear direction) where the tip tool 50 is detachably mounted. Although the hole 36a is formed, the anvil 36 and the output shaft may be configured to connect separate parts. The tip tool 50 mounted in the mounting hole 36a has a hexagonal cross-sectional shape perpendicular to the axial direction in the same manner as the inner shape of the mounting hole 36a, and a hexagonal shape at a certain distance from both ends. A constricted portion 50c having a size smaller than the width is formed. The two constricted portions 50c are provided because the end portions of the tip tool are formed with the same or different thread threads 50a and 50b, and thus are used alternatively.

  At the front end portion of the anvil 36, a ball insertion hole 36d designed so that the ball 42 does not fall into the mounting hole is formed, and a mounting portion 40 for mounting the tip tool 50 with one touch is provided. The shape of the ball insertion hole 36d is formed so that the ball 42 does not fall out from the radially outer side. In the mounting portion 40, the guide sleeve 41 is locked by a guide spring 43, a washer 44, and a retaining ring 45 so that the guide sleeve 41 can move forward from the state shown in FIG. The rear end of the guide spring 43 is held by the front side surface of the flange portion 41 b formed on the guide sleeve 41, and the front end is in contact with the washer 44. The washer 44 is held so as not to move in the axial direction by a retaining ring 45 attached to a circumferentially continuous groove portion 36 f near the front end of the anvil 36. The guide sleeve 41 is preferably made of metal, such as iron or any alloy. The flange portion 41b formed slightly rearward from the axial center of the guide sleeve 41 is brought into contact with the outer peripheral side of the ball 42 so that the flange 42b moves toward the outer peripheral side of the ball 42 in the state shown in FIG. Restrict movement of At this time, since the ball 42 is in a position to engage with the constricted portion 50c, the tip tool 50 cannot be removed unless the guide sleeve 41 is moved forward in the axial direction in the state of FIG. When the guide sleeve 41 is locked at a steady position as shown in FIG. 2, the ball 42 falls into the constricted portion 50 c of the tip tool, and a flange portion formed on the guide sleeve 41 that projects the movement of the ball 42 radially inward. By restricting on the inner surface of the (convex portion) 41b, the mounted tip tool 50 is prevented from moving in the axial direction, and the tip tool 50 is configured not to fall off the anvil 36 serving as the output shaft. When the guide sleeve 41 is moved forward in the axial direction from the steady position shown in FIG. 2, the flange portion 41b located on the outer peripheral side of the ball 42 moves forward, so that the ball 42 is restricted from moving to the outer peripheral side. Accordingly, when the tip tool 50 is pulled forward in the axial direction in this state, the ball 42 moves radially outside in the ball insertion hole 36d along the curved surface of the constricted portion 50c, and the tip tool 50 is radially outside. Therefore, the tip tool 50 can be pulled forward without resistance.

  FIG. 3 is a side view showing the shape of the anvil 36 alone in FIG. As shown in FIG. 3, a thin diameter portion 36e having a diameter smaller than that of the metal 18a (see FIG. 1) is formed at the front end portion of the anvil 36 to attach the mounting portion 40, and on the rear side of the small diameter portion 36e. A dihedral width 38 is formed near the front side of the portion where the diameter is slightly thick. In FIG. 3, a diagonal line having a width of two faces 38 formed in a quadrangular shape is illustrated as being connected by a line, but this is illustrated to indicate that the plane is not a curved surface but a plane. On the front side of the small diameter portion 36e, a circumferentially continuous groove portion 36f for fixing the retaining ring 45 of the mounting portion 40 is formed. Near the rear end of the anvil 36, a blade portion 37 is formed extending radially outward from a cylindrical central portion. The width across flats 38 is preferably formed at a position facing the guide sleeve 41. When the guide sleeve 41 is in a steady position, it is covered with the guide sleeve 41 so that the width across flats 38 cannot be seen from the outside. When the tip tool 50 is broken as described above, the mounting portion 40 at the tip of the anvil 36, that is, the guide sleeve 41, the ball 42, the guide spring 43, the washer 44, and the retaining ring 45 is removed, whereby the anvil 36 is removed. The formed width across flats 38 can be exposed to the outside. When the guide sleeve 41 is in the steady position, the guide sleeve 41 is partially or entirely covered by the guide sleeve 41. However, when the guide sleeve 41 is moved forward, the width across flats 38 is completely exposed. With this configuration, it is not necessary to remove the mounting portion 40 in order to prevent rotation of the output shaft using the width across flats 38.

  4 is a cross-sectional view taken along a line AA in FIG. A mounting hole 36a having a regular hexagonal cross section perpendicular to the axial direction is formed in the anvil 36, and two ball insertion holes 36d for receiving the balls 42 are provided at two opposing positions of the mounting hole 36a. The ball insertion hole 36d has a shape in which an opening on the side close to the central axis of the anvil 36 (inner peripheral side opening) is narrowed. That is, the ball 42 can be inserted through the opening on the outer peripheral side of the ball insertion hole 36d, but cannot be penetrated radially inward from the opening on the inner peripheral side. A two-sided width 38 is formed on the outer peripheral portion at a position 90 degrees apart from the two ball insertion holes 36d. The two-surface width 38 is a parallel plane located in two opposite directions (here, the vertical direction) as viewed from the central axis, and the two-surface width 38 is a fixing member having a parallel opposing surface, such as a spanner or a dedicated fixing. The anvil 36 can be prevented from rotating by being fixed with a tool or the like. When the anvil 36 is fixed using this width across flats 38, the trigger 3a is pulled to activate the motor 3, the hammer 33 strikes the anvil 36, and the tip tool 50 is not easily inserted into the anvil tip tool mounting hole. It is possible to apply the same striking force to the anvil 36 and the tip tool 50, and to remove the tip tool 50 remaining in the tip tool mounting hole.

  FIG. 5 is a partially enlarged sectional view showing the impact tool striking mechanism and the vicinity of the tip tool mounting portion according to the second embodiment of the present invention. The second embodiment differs from the first embodiment in that the shape of the anvil 66 is different and the position of the formed two-sided width 68 is provided between the guide sleeve 41 and the housing. Other components can be the same as those in the first embodiment. The anvil 66 is longer in the axial direction than the anvil 36 of the first embodiment. The distance d between the rear end of the mounting portion 40, particularly the rear end of the guide sleeve 41 and the front end of the broad housing (here, the front end of the hammer case 4) is substantially the same as or slightly the length in the front-rear direction of the width across flats 68. It is formed to be long. In the second embodiment, the front and rear length of the impact tool is long, but the two-sided width 68 is formed in a place where it can be seen from the outside, so that the mounting portion 40, that is, the guide sleeve 41, the ball 42, the guide spring 43, and the washer 44. A spanner or the like can be easily inserted without removing the retaining ring 45, and the same effect as in the first embodiment can be obtained.

  6 is a cross-sectional view taken along the line BB in FIG. The two-sided width 68 can be formed by cutting a part of the outer peripheral portion of the anvil 36 and has substantially the same shape as the two-sided width 38 of the first embodiment. Since the axial position of the through-hole 66d in which the boss is disposed is different from the axial position of the two-sided width 68, it is advantageous from the viewpoint of securing the strength of the anvil 66.

  FIG. 7 is a partially enlarged sectional view showing the impact tool striking mechanism and the vicinity of the tip tool mounting portion according to the third embodiment of the present invention. The third embodiment is particularly characterized by the shape of the anvil 86 and the shape of the guide sleeve 91. Here, the anvil 86 and the guide sleeve 91 are fixed so as not to be relatively rotatable with respect to the rotation direction, and the anvil 86 is also made non-rotatable when the guide sleeve 91 is fixed from the outside. That is, the guide sleeve 91 is held so as to be movable within a predetermined range in the axial direction with respect to the anvil 86, but is held non-rotatable in the rotational direction. Of the components constituting the holding portion 90, the same components as those of the first and second embodiments can be used for the other components excluding the guide sleeve 91, that is, the ball, the guide spring, the washer, and the retaining ring.

  FIG. 8 is a cross-sectional view of the CC and DD portions of FIG. As can be seen from (1), a one-surface width 88 is provided on the sliding portion of the anvil 86 and a one-surface width 91 d of substantially the same size is provided on the inner peripheral surface of the guide sleeve 91 so as to be engageable with each other. On the other hand, as shown in (2), two face widths 91e are provided at two opposing positions on the outer peripheral surface of the guide sleeve 91. In the DD sectional view shown in (2), illustration is omitted, and there is a space inside the guide sleeve 91 and the outside of the anvil 86, but a guide spring is actually arranged in this space. In the space in which the guide spring slides, a rotation stop portion with respect to the rotation direction of the anvil 86 and the guide sleeve 91 cannot be arranged. Therefore, as shown in (1), the guide is guided at the rear portion of the guide spring. The sleeve 91 is provided with a non-rotating portion, that is, one surface width 88, 91d. In addition, you may comprise so that the one surface width 88, 91d provided in the sliding part of the anvil 36 or the guide sleeve 91 may be provided not only in one place but in multiple places in the circumferential direction. Further, since the anvil 36 and the guide sleeve 91 may be formed so as not to be able to rotate relative to each other, a rotation-preventing structure may be realized by a key groove and a convex portion continuous in the axial direction. Furthermore, the two-sided width 91e provided on the outer peripheral portion of the guide sleeve 91 may be configured to provide not only two opposing surfaces but also a plurality of flat surfaces beyond that.

  According to the third embodiment described above, the guide sleeve 91, the ball, and the guide of the mounting portion provided at the tip of the anvil 86 are fixed by fixing the two-surface width 91e of the outer peripheral portion of the guide sleeve 91 with a vise or the like. The rotation of the anvil 86 can be indirectly fixed without removing the spring, washer, and retaining ring, and the same effect as in the first and second embodiments can be obtained.

  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, the shape of the engaging portion for suppressing rotation formed in the anvils 36, 66, 86 can be various types. FIG. 9 is a diagram showing an alternative to the shape of such an anvil and engaging portion. These are sectional views of positions corresponding to, for example, the AA portion in FIG. 3, the BB portion in FIG. 5, or the CC portion in FIG. 7. (1) is the same as that of the first and second embodiments, and a two-sided width 101 a is provided on the outer periphery of a cylindrical anvil 101. In (2), the outer periphery of the cylindrical anvil 102 is formed in a cubic shape, and the cross-sectional shape perpendicular to the axial direction is a square having four flat portions 102a. In (3), the cross-sectional shape perpendicular to the axial direction of the cylindrical anvil 103 is a regular hexagon having six plane portions 103a. (4) is one in which two convex portions 104a are formed on the outer peripheral portion of a cylindrical anvil 104, and the convex portions 104a are formed at opposing positions (positions that are rotationally symmetric). (5) is one in which two concave portions 105a are formed on the outer peripheral portion of the cylindrical anvil 105, and the concave portions 105a are formed at opposing positions (positions that are rotationally symmetric).

  In the above-described embodiment, an example of an impact tool that can continuously rotate with respect to the anvil 86 while the hammer 33 is retracted in the axial direction has been described. However, the hammer can only perform relative rotation of less than one rotation with respect to the anvil. The present invention can be similarly applied to a so-called electronic pulse type impact tool (see Japanese Patent Application Laid-Open Nos. 2011-31313 and 2011-62771 by the applicant) in which the hammer cannot move in the axial direction. Further, the present invention can be similarly applied to a rotary tool having a tip tool mounting portion such as the mounting portion 40 on the output shaft.

DESCRIPTION OF SYMBOLS 1 Impact tool 2 Housing 2a Body part 2b Handle part 2c Battery mounting part 3 Motor 3a Rotor 3b Stator 3c Magnet 3d Rotating shaft 4 Hammer case 5 Battery 5a Release button 6 Belt hook 7 Trigger switch 7a Trigger 8 Forward / reverse switching lever 9 Control circuit Substrate 10 Control panel 11 Signal line 12 Inverter circuit board 13 Switching element 14 Rotor fan 15 Rotation position detection element 17a, 17b Air intake hole 18a Metal 18b, 19a, 19b Bearing 20 Reduction mechanism 30 Impact mechanism 31 Spindle 31a Spindle cam groove 31b Fitting shaft 32 Ball 33 Hammer 33a Hammer cam groove 34 Claw portion 35 Spring 36 Anvil 36a Mounting hole 36b Fitting hole 36d Ball insertion hole 36e Small diameter portion 36f Groove portion 37 Blade portion 38 Width across flats 40 Mounting part (tip tool mounting part)
41 Guide sleeve 41a Large diameter portion 41b Flange portion 41c Small diameter portion 42 Ball 43 Guide spring 44 Washer 45 Retaining ring 48 Light emitting means 50 Tip tool 50a, 50b Thread 50c Constricted portion 55a, 55b Fracture surface 56 Arrow 66 Anvil 66d Through hole 68 Two-sided width 86 Anvil 88 One-sided width 90 Holding part 91 Guide sleeve 91d One-sided width 91e Two-sided width 101, 102, 103, 104, 105 Anvil 101a Two-sided width 102a, 103a Flat part 104a Convex part 105a Concave part 136 Anvil 136a Mounting Hole 151a Outer edge 151b Outer edge position

Claims (8)

A driving source;
A striking mechanism having a hammer rotated by the drive source and an anvil striked by the hammer ;
A hammer case that houses the striking mechanism ,
A mounting hole for mounting a tip tool is formed in the output shaft of the anvil, the rear end side of the output shaft is accommodated in the hammer case, and the front end side is exposed forward from the hammer case.
In an impact tool having a tip tool mounting portion for holding the tip tool mounted,
The mounting hole has a polygonal cross-sectional shape perpendicular to the axial direction,
An impact tool, wherein an engagement portion for preventing rotation of the output shaft from the outside of the hammer case is provided in a portion of the output shaft exposed from the hammer case .   2. The impact tool according to claim 1, wherein the engaging portion is at least two opposing flat surfaces formed on an outer peripheral portion of the output shaft.   The impact tool according to claim 1, wherein the engaging portion is a plurality of concave portions or convex portions formed on an outer peripheral portion of the output shaft. Before SL output shaft is manufactured integrally with the main body portion of the anvil,
The tip tool mounting portion, the impact tool according to claim 2 or 3, characterized in that it has a slidable guide sleeve in the axial direction with respect to that formed in the vicinity of the front end of the output shaft and the output shaft. The impact tool according to claim 4, wherein the engaging portion is provided in a portion exposed when the guide sleeve of the output shaft is moved from a normal position. The engaging portion, the impact tool according to claim 4 or 5, characterized in that formed between the front end of the rear end and the hammer case before Symbol guide sleeve. The output shaft and the guide sleeve are each provided with a rotation preventing portion for preventing relative rotation with respect to the rotation direction,
The impact tool according to claim 4 , wherein the rotation of the output shaft can be prevented by preventing the rotation of the guide sleeve. The detent portion is at least one flat surface formed on the output shaft and the guide sleeve and capable of engaging with each other,
The impact tool according to claim 7, wherein at least two opposing surfaces are provided on an outer peripheral portion of the guide sleeve.

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