Power tool

Abstract

To provide an electric tool which facilitates operation such as hanging of a hook on a nail head when a partial device is engaged with a work object, and improves handleability and ease of handling of a device.SOLUTION: An electric tool is used in work such as nail pulling. The electric tool 1 includes a body part 10, an engagement member 20 which is provided on the body part 10 side and has an engagement part 22 engaged with a part of a work object, a slide member 30 which is projectable into / withdrawable from the body part 10, and partially approaches and separates the engagement member 20, and a drive source 60 operating the slide member 30. The engagement part 22 of the engagement member 20 is arranged at a position offset from a drive shaft DA. The engagement part 22 is formed so as to project in a direction perpendicular to the drive shaft DA.SELECTED DRAWING: Figure 24B

Description

Technical Field

[0001] The present invention relates to a power tool.

Background Art

[0002] At a construction site, after pouring concrete into a mold made of a plate such as a concrete panel and then separating the plate material and the frame material, a nail pulling operation may be required. In such a situation, a mechanized power nail puller such as an air type, a hydraulic type, or an electric type may be used. As a conventional nail puller used in such a situation, a structure in which a screw is cut on a hook for hooking a nail and the hook is moved up and down by transmitting the rotation of a motor to pull out the nail is generally proposed (see, for example, Patent Documents 1 and 2).

[0003] In such a nail puller, when pulling out a nail, a hook is arranged on the axis of the ball screw so that a straight load acts on a mechanism (for example, a ball screw) for transmitting the rotation of the motor, and the nail is pulled out along the axis. Such a configuration is generally adopted.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, with the above configuration, it is difficult to say that the operation of hanging the hook on the nail head is easy because the hook position is difficult to see.

[0006] Therefore, an object of the present invention is to provide a power tool that facilitates an operation when engaging a part of the device with a work target, such as hanging a hook on a nail head, and improves the maneuverability and ease of handling of the device.

Means for Solving the Problems

[0007] One aspect of the present invention is a power tool used for operations such as nail pulling, comprising: a main body portion; an engaging member provided on the main body portion side and having an engaging portion that engages with a part of the work target; a sliding member that moves in and out with respect to the main body portion and approaches and separates from the engaging member; a drive source for operating the sliding member; and the engaging portion of the engaging member is arranged at a position offset from the drive shaft.

[0008] In the power tool of the above aspect, since the engaging portion of the engaging member is offset from the drive shaft, the engaging portion is easily visible to the operators, and a structure can be adopted that facilitates an operation when engaging the engaging portion of the device with the work target, such as hanging a hook on a nail head. According to this, it is easy to improve the maneuverability and ease of handling of the device.

[0009] More specifically, it is as follows. That is, in the conventional mechanism, when pulling out a nail driven obliquely, an eccentric load acts on the ball screw, causing eccentric wear on the screw part and reducing durability. The reason for the generation of the eccentric load is that the penetration position of the nail is displaced with respect to the drive shaft, causing a lateral load to act on the ball screw. Therefore, in the conventional mechanism, the "hook position" for hooking the nail head is arranged "on the drive shaft" so as not to generate an eccentric load. However, although this arrangement is effective in improving durability, there is a problem that the tip is difficult to see (difficult to aim). Also, even though the hook is arranged on the shaft, when the nail is driven obliquely, the position where the pulling resistance occurs is displaced from the shaft, so the generation of the eccentric load cannot be completely eliminated. In this regard, in this aspect, since the engaging portion is fixed to the main body and the sliding member is driven to push the driving member, even if the penetration position of the nail is displaced from the drive shaft, the eccentric load acting on the engaging portion can be received by the main body portion, which is much more rigid than the drive mechanism, so no durability problem occurs. Further, since the sliding member is provided with a guide portion (a member that can function as a guide portion) for guiding the movement in the axial direction, the force acting on the drive shaft always acts on the shaft regardless of the position of the nail, so there is no need to provide the engaging portion on the extension line of the drive shaft. Therefore, this aspect enables the offset arrangement of the engaging portion, leading to the solution of the problem of "difficulty in aiming at the nail". Furthermore, even when pulling out an obliquely driven nail, the durability of the power tool body is not reduced.

[0010] In the power tool as described above, the engaging portion may be formed so as to project in a direction perpendicular to the drive shaft that passes through the sliding member and extends along the sliding direction of the sliding member.

[0011] In the power tool as described above, the engaging member may be configured to be able to change the direction in which the engaging portion projects.

[0012] In the power tool as described above, a portion including the engaging portion of the engaging member may be provided as a rotatable portion that is rotatable around the drive shaft.

[0013] The electric power tool as described above may further include a resistor that applies a predetermined resistance to the rotational movement of the rotatable portion of the engaging member about the drive shaft.

[0014] The electric power tool as described above may further include a defining means for defining the circumferential position of the rotatable portion of the engaging member as the sliding member slides.

[0015] In the electric power tool as described above, the sliding member may be formed with a holding portion capable of sandwiching a member disposed perpendicular to the drive shaft together with the engaging portion of the engaging member.

[0016] In the electric power tool as described above, the portion of the sliding member including the holding portion may be provided as a rotatable portion rotatable about the drive shaft.

[0017] The electric power tool as described above may further include a resistor that applies a predetermined resistance to the rotational movement of the rotatable portion of the sliding member about the drive shaft.

[0018] The electric power tool as described above may further include a defining means for defining the circumferential position of the rotatable portion of the sliding member as the sliding member slides.

[0019] In the electric power tool as described above, in a state where the sliding member is in the initial position retracted into the main body portion, the holding portion may be formed at a position where at least a part thereof overlaps with the engaging portion of the engaging member in the axial direction of the drive shaft.

[0020] The electric power tool as described above may further include a side cover portion provided around the sliding member.

[0021] The side cover portion in the electric power tool as described above may be attached to the sliding member and slide integrally with the sliding member.

[0022] In the power tool as described above, a holding portion capable of sandwiching a member disposed perpendicular to the drive shaft together with the engaging portion of the engaging member is formed on the sliding member, and at least a part of the holding portion and the engaging portion may be formed so as to be located outside the cover.

[0023] In the power tool as described above, the holding portion of the sliding member may be formed to project in a direction perpendicular to the drive shaft with respect to the engaging portion of the engaging member.

Advantages of the Invention

[0024] According to the power tool of the present invention, it is possible to facilitate the operation when engaging a part of the device with the work target, such as hanging a hook on the nail head, and improve the maneuverability and ease of handling of the device.

Brief Description of the Drawings

[0025]

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Embodiments for Carrying Out the Invention

[0026] Hereinafter, embodiments of the power tool according to the present invention will be described with reference to the drawings.

[0027] [First Embodiment] As a first embodiment of the present invention, a form in which a power tool is used as a rechargeable nail puller will be described (see FIG. 1 and the like). The rechargeable nail puller 1 is a type of rechargeable power tool used for nail pulling operations such as pulling out nails P penetrated into plate materials or framing materials such as concrete panels Q and wooden beams R. The rechargeable nail puller 1 of the present embodiment is a tool including a main body portion 10, a hook member 20, a slider 30, a cover 50, a motor 60, etc. (see FIGS. 1 to 19B and the like). The hook member 20 fixed to the main body portion 10 side is hung on the nail head Ph, and the nail pulling operation is configured to be performed along with the movement when the slider 30 is projected from the main body portion 10 along the drive shaft DA in that state (see FIG. 19B and the like). First, the configuration of the rechargeable nail puller 1 will be described below, and then the operation of the rechargeable nail puller 1 will be described.

[0028] The main body portion 10 is a portion that constitutes the main body of the rechargeable nail puller 1, and in this specification, it refers to a portion excluding the drive portion (such as the slider 30) in particular. The main body portion 10 of the present embodiment mainly includes a mechanism portion 11 that houses the motor 60 and the like, a grip portion 12 that a user U (only the hand portion having the rechargeable nail puller 1 is shown in FIGS. 7A and 8A) grips during use, and a battery housing portion 13 that houses the battery 66 and the like (see FIGS. 3 to 5 and the like).

[0029] The mechanism portion 11 is a portion that houses a drive mechanism (for example, a speed reducer 71, a screw shaft 72, etc.) 70 for transmitting the driving force of the motor 60 to the slider 30 in addition to the motor 60 (see FIG. 6B and the like). The main frame 14, the cover 50, the hook member 20, etc. are further provided in this mechanism portion 11 (see FIG. 6A and the like).

[0030] The grip portion 12 is formed in a shape that connects the battery housing portion 13, which is relatively heavy and bulky, and the mechanism portion 11 at a portion excluding the extension line of the drive shaft DA. When the user grips this grip portion 12 and lifts the charging nail puller 1, the overall structure is configured to have a good weight balance and be easy to handle (see FIGS. 4, 5, etc.). The grip portion 12 of the present embodiment is formed to extend in a direction perpendicular to the drive shaft DA. Of course, in consideration of ease of performing nail pulling operations and the like, it may be formed to extend slightly obliquely. A trigger switch 122 that can be operated with a finger is provided at a portion of the grip portion 12 closer to the mechanism portion 11 (see FIG. 3, etc.). Although not described in detail here, the grip portion 12 is formed in a shape and size that is easy to grip, and a flexible member is disposed on the surface, and other processes are performed to make it non-slip and easy to grip.

[0031] The battery housing portion 13 is a portion that houses a rechargeable battery 66 or the like, and is also a portion where the weight tends to be bulky in the main body portion 10. In the present embodiment, the battery housing portion 13 is configured by a substantially rectangular parallelepiped housing, and is shaped and sized to be easily compatible even when accommodating a large battery 66 (see FIGS. 6A, etc.). According to the charging nail puller 1 of the present embodiment having a built-in rechargeable battery 66, it is possible to perform nail pulling operations in a cordless state as a cordless hand tool. Further, the surface of the battery housing portion 13 on the side opposite to the grip portion 12 is flat, and a rubber pad (not shown) or the like is attached as needed, and is configured to be a placement surface 13S when placed in a stable posture on the ground or floor surface when not in use (placement state) (see FIGS. 1, 3, etc.). The battery housing portion 13 of the present embodiment is further provided with a strap 132 and a belt hook 134 (see FIG. 2, etc.).

[0032] Incidentally, the relationship between the description in the drawings and the posture of the charging nail puller 1 will be mentioned here. When the charging nail puller 1 of the present embodiment is actually used for nail pulling work (in the use state), the posture (the orientation of the charging nail puller 1) is not particularly limited. For example, if the nail P penetrated into the wall surface is to be horizontally pulled out, it can be used in a posture with the hook member 20 and the slider 30 (detailed later) facing sideways, similar to the placement state. Or, if the nail P penetrated into the ceiling is to be pulled out directly downward, it can be used in a posture with the hook member 20 and the slider 30 facing directly upward. However, in light of the actual use situation, it is assumed that the operation of pulling out the nail P from the building materials or framing materials such as the concrete panel Q or the purlin R placed at the feet directly upward is usually performed. In this specification and the drawings, assuming such a normal scenario, the mode of use in a state where the hook member 20 and the slider 30 are directed downward will be described as a representative example during use, called the "use state" (see Fig. 2 etc.). Also, for convenience, the upper side (the direction along the drive shaft DA that is upward) in the use state will be called upward, the lower side will be called downward, the side where the mechanism part 11 is located as seen from the user will be called forward, and the side where the battery housing part 13 is located will be called rearward (see Fig. 7A etc.).

[0033] The hook member 20 functions as a member that engages with a part of the work object (in this embodiment, the head of the nail P (nail head Ph) to be pulled out from a crossbar or the like). A hook (engagement part) 22 is formed at its tip. The shape of the hook 22 is not particularly limited as long as it can engage with the nail head Ph. In this embodiment, the hook 22 is formed by a pair of symmetrical claws whose width gradually narrows as it goes forward when viewed from below, like the tip of a normal nail puller (bar) (see FIG. 5 etc.). Also, the hook 22 is more likely to catch on the nail head Ph if it has a wedge shape in which the thickness gradually thins as it goes forward when viewed from the side (the left - right direction perpendicular to the front - rear direction in the use state) (see FIG. 6B etc.). The hook member 20 with the hook 22 formed thereon is fixed to the main frame 14 of the mechanism part 11 (see FIG. 11 etc.). The hook member 20 is formed in a cylindrical shape in this embodiment for example (see FIG. 14A etc.), and also functions as a guide member for guiding the rod part 32 of the slider 30 that slides in the vertical direction (this will be described later) (see FIG. 13 etc.).

[0034] The main frame 14 is a frame formed to extend in the vertical direction (the direction from above to below) along the drive shaft DA in the mechanism part 11 of the main body part 10 (see FIG. 12 etc.). In this embodiment, a pair of left - and - right plate - like members symmetrically arranged with the drive shaft DA in between are adopted as the main frame 14 (see FIG. 9A, FIG. 9B etc.). The upper end part of the main frame 14 is attached and fixed to the frame base 15 (see FIG. 13 etc.). At the tip part (lower part) of the main frame 14, the hook member 20 is screwed, for example, from both sides with fastening screws 24 (see FIG. 14A etc.). The hook member 20 in a state fixed to the main frame 14 does not change its relative position in the vertical direction (the direction along the drive shaft DA) within the mechanism part 11. In addition to the role of holding the hook member 20 fixed in this way, the main frame 14 also serves as a guide member for guiding the slider 30 that slides in the vertical direction.

[0035] The slider (sliding member) 30 slides in the vertical direction and projects in and out with respect to the main body 10, and a part thereof (the tip 31) approaches and separates relative to the hook 22 of the hook member 20, functioning like a leg (pusher or push rod). By projecting the slider 30 with the hook 22 of the hook member 20 engaged with the nail head Ph, the hook 22 of the hook member 20 fixed to the main body 10 side and the tip 31 of this slider 30 are relatively separated, and the nail P can be pulled out along with this operation (see FIGS. 7B, 8B, etc.). The slider 30 of the nail extractor 1 of the present embodiment configured as described above can be said to function like a bracing bar when pushing up the main body 10 together with the hook 22 against a nailed concrete panel Q, a crosspiece R, etc. (see FIG. 16, etc.).

[0036] The specific configuration of the slider 30 is not particularly limited as long as it can function as described above. In the present embodiment, which is a preferred example, it is configured such that the tip 31, the rod portion 32, and the side cover portion 33, which slide in the vertical direction along the main frame 14 provided on the main body 10, are integrated (see FIG. 14B, etc.). The slider 30 has the driving force of the motor 60 transmitted thereto via a driving mechanism 70 including a screw shaft 72, and performs a linear motion along the drive shaft DA.

[0037] The tip 31 is formed of, for example, a substantially circular plate-like member formed at the lower part of the slider 30, and serves as a bracing portion that abuts against a concrete panel Q, a crosspiece R, etc. and relatively pushes up the main body 10 (see FIGS. 7A, 8A, etc.).

[0038] The rod portion 32 is composed of a rod-shaped member extending along the drive shaft DA, and is integrated with the tip portion 31 at its lower tip (see FIG. 14B, etc.). The rod portion 32 has a cylindrical shape such that the screw shaft 72 passes through its inside (see FIG. 6A, etc.). Further, a sleeve portion 32c having a female screw 32b that engages with the screw shaft 72 is provided on the inner circumference of a part of the rod portion 32, for example, the upper flange portion 32a. Along with the rotational movement of the screw shaft 72, the rod portion 32 and thus the entire slider 30 are adapted to linearly move along the drive shaft DA (see FIG. 6B, etc.). By such a screw shaft 72, female screw 32b, and further a steel ball (not shown) interposed between the screw shaft 72 and the female screw 32b, a drive mechanism 70 for linearly moving the slider 30, for example, a ball screw (indicated by reference numeral 73 in FIG. 9A, etc.) as in the present embodiment is constituted. The outer diameter of the rod portion 32 is formed to be less than the inner diameter of the hook member 20, and it is disposed inside the hook member 20 and guided by the inner peripheral surface of this hook member 20 during sliding (linear movement) (see FIG. 10B, FIG. 13, etc.). The rod portion 32 is fastened and integrated with the side cover portion 33 by a screw (such as a dish cap bolt) 39 at its lower end portion (see FIG. 10B, FIG. 11, etc.).

[0039] The side cover portion 33 is composed of a member that constitutes the peripheral portion of the slider 30 (see FIG. 14B, etc.). In the present embodiment, the side cover portion 33 is provided so as to surround the main frame 14. Further, both side portions of this side cover portion 33 are formed such that their cross-sectional shapes are channel-shaped, and the main frame 14 is sandwiched by the groove portions (see FIG. 9A, FIG. 9B, etc.). The side cover portion 33 formed in this way slides (linearly moves) along the drive shaft DA together with the tip portion 31 and the rod portion 32 while being guided by the main frame 14 (see FIG. 12, etc.). A cover 50 is provided around the side cover portion 33.

[0040] The cover 50 is composed of a cylindrical member provided in the mechanism portion 11 so as to cover the periphery of the side cover portion 33 (see FIG. 6A, etc.). The cover 50 of the present embodiment is provided such that when the slider 30 is in the retracted state (initial position) housed in the main body portion 10, the portion of the slider 30 excluding the tip portion 31 is hidden (see FIG. 7B, etc.).

[0041] The motor 60 is provided as a power source for driving (linear motion) the slider 30, which is a movable part, via the drive mechanism 70. The motor 60 of the present embodiment is provided at an upper position within the mechanism portion 11 in the main body portion 10 (see FIG. 6A, etc.).

[0042] The drive mechanism 70 is a mechanism configured to transmit the power of the motor 60 and drive (linear motion) the slider 30, which is a movable part. The drive mechanism 70 of the present embodiment includes a speed reducer 71 and a ball screw 73 (see FIG. 6A, etc.). Although not shown in particular detail, the speed reducer 71 includes a gear train or the like that appropriately reduces the rotational speed of the motor 60 and transmits it to the screw shaft 72 of the ball screw 73. The screw shaft 72 is provided along the drive shaft DA and rotates to drive (linear motion) the slider 30.

[0043] The control device (control unit) 90 is built into the main body portion 10 as a device for controlling the motor 60. The control device 90 of the present embodiment is connected to the motor 60 so as to be capable of two-way communication and can transmit and receive control signals. In addition, it is also connected to each of the origin sensor 80, the trigger switch 122, the mode operation / display unit 92, and the battery housing portion 13 (the battery 66 housed therein) (see FIG. 31). Further, although not particularly shown, the control device 90 includes a communication circuit, a converter circuit, an inverter circuit, and an MPU for controlling the communication circuit for communicating with these components.

[0044] As described above, in the present embodiment, the screw shaft 72 is provided along the drive shaft DA, and the speed reducer 71 is provided above the screw shaft 72 at a position on the extension line of the drive shaft DA. Further, a motor 60 is provided above the speed reducer 71 at a position on the extension line of the drive shaft DA (see FIG. 6A and the like). As a result, in the charging nail puller 1 of the present embodiment, the motor 60 and the drive mechanism 70 (the speed reducer 71, the ball screw 73, and its screw shaft 72) are arranged coaxially and in series. Such a configuration, combined with the configuration that enables the overall height of the charging nail puller 1 to be reduced, contributes to improving the ease of operation and aiming.

[0045] That is, first, in the charging nail puller 1 of the present embodiment, instead of stroking the hook member 20 as before, the hook member 20 is fixed, and instead, the slider 30 is stroked to relatively move the hook member 20. In this case, it is not necessary to secure a space inside the main body 10 for stroking the hook member 20. When such a configuration is adopted, the length L1 corresponding to the internal space required for the stroke of the hook member that should have been secured inside the main body 10 (substantially equal to the stroke amount of the hook member 20) is reduced, and the overall height of the charging nail puller 1 in the use state (however, the retracted state where the slider 30 is retracted into the main body 10 and is in the initial position), that is, the length of the mechanism portion 11 along the drive shaft DA, can be lowered, which means that the overall height can be reduced (see FIGS. 15 and 16 and the like. In FIG. 15(B), the conventional charging nail puller is shown as a comparison target with the reference numeral 1'). The height of the mechanism portion 11 in the initial position (retracted state) (the length from the tip portion 31 to the upper part of the mechanism portion 11 along the drive shaft DA) is indicated by the reference numeral L2 (see FIG. 16).

[0046] Second, by enabling the reduction of the overall height as described above, it becomes easier to arrange the motor 60 on the drive shaft DA (or on its extension line). For example, in the past, in order to avoid excessive increase in the overall height, the motor 60 that had to be offset and arranged within the hand grip 12 can be arranged on the drive shaft DA (or on its extension line) in the present embodiment where the overall height is reduced. In such a case, it is possible to configure the hand grip 12 to be closer to the mechanism portion 11 and the hook 22. When the hand grip 12 is close to the mechanism portion 11 and the hook 22 in this way, it contributes to making it easier to handle and aim in the actual nail pulling operation, especially in operations such as hooking the hook 22 onto the nail head Ph. Moreover, since the force acting on the screw shaft 72 acts directly below (coaxially) the screw shaft 72 regardless of the position and the driving direction of the nail P, it is not necessary to provide the hook 22 directly below the drive shaft DA, which also contributes to solving the problem of "difficulty in aiming at the nail".

[0047] Also, arranging the motor 60, the speed reducer 71, and the screw shaft 72 close to each other in a straight line leads to the omission of the conventional power transmission mechanism (such as bevel gears) arranged between them, resulting in a simpler structure and contributing to miniaturization and weight reduction. In addition, such a rechargeable nail puller 1 is convenient and easy to use even in a narrow space.

[0048] Also, when using a tool for pulling nails that strikes the nail foot Pt to pull out the nail P, the removed nail P may scatter due to the forceful strike. However, according to the rechargeable nail puller 1 of the present embodiment as described above, it is possible to pull out the nail without scattering.

[0049] Also, in the case of a structure where the main body 10 itself strokes and moves (that is, moves away from the concrete panel Q, the crossbar R, etc. together with the hook 22) along with the nail extraction operation like the nail extractor 1 of the present embodiment (see FIGS. 7A to 8B, etc.), there is also an advantage that it is easy for the user to feel the nail extraction. That is, in the case of a conventional structure where the hook slides inside the main body, the user who holds the nail extractor by hand can only confirm the nail extraction operation by seeing it with the eyes or hearing the operation sound. On the other hand, according to the nail extractor 1 of the present embodiment, it is easy to realize that the nail extraction operation is performed and completed while directly feeling the movement that the main body 10 itself strokes (rises) along with the nail extraction operation.

[0050] [Second Embodiment] As a second embodiment of the present invention, further features of the hook member 20 and the hook 22 of the nail extractor 1 will be described. Note that the description will not be repeated for the other configurations of the nail extractor 1 that are common to those in the first embodiment.

[0051] <Structure for suppressing the influence of eccentric load> In constructing the charging nail puller 1 as described above, it is preferable to also consider the problem of "uneven load" acting on the drive shaft. In the case of a conventional structure in which the nail P is pulled out by moving the hook 22', if the nail P penetrates straight into the concrete panel Q or the cross member R, the force acting on the drive shaft when pulling out the nail P does not act in a direction other than the axial direction, so an uneven load (uneven load) does not act (see FIGS. 17A and 17B). However, in reality, the nail P often penetrates obliquely (see FIG. 17C). When pulling out the nail P, the pulling resistance of the nail occurs at a position offset from the drive shaft, and due to this, a lateral load acts on the drive shaft as an uneven load (see FIGS. 18A and 18B). That is, the resistance during nail pulling occurs at the frictional resistance portion between the concrete panel Q or cross member R, which is the driving member, and the nail P. More specifically, it occurs at the portion of the nail P that penetrates into the cross member R or the like (the portion marked with fine dots in FIG. 18B). Therefore, it can be explained that the reason why an uneven load acts on the obliquely driven nail P as described above is that the portion where such resistance occurs (the penetrated portion of the nail P) is offset (offset) with respect to the drive shaft. When an uneven load acts, the inclination of the screw shaft 72' occurs, and as the pulling amount of the nail P increases, the inclination also increases. As a result, uneven wear occurs due to the load acting on the bearing portion of the screw shaft 72', and the durability may decrease. Thus, since an uneven load is generated due to the misalignment between the drive shaft and the nail, if the hook 22 is arranged at a position offset from the drive shaft DA as in the present embodiment, the situation may be even more serious. In consideration of such a problem of uneven load and as one of the configurations that can suppress and eliminate its influence as much as possible, in a conventional mechanism, there is one in which the position of the hook for hooking the nail head is arranged on the drive shaft so that no uneven load is generated. However, such an arrangement as in this conventional mechanism is disadvantageous in that the tip of the nail is difficult to see (difficult to aim at), even though it is effective for improving durability. Also, it is not possible to avoid the uneven load that occurs when pulling out an obliquely penetrated nail. In this regard, in the present embodiment that comprehensively considers various issues, a rigid structure is adopted in which the tip of the nail is easy to see (easy to aim at) and is less affected by uneven load. That is, the hook on which an oblique or lateral eccentric load acts is supported by the main frame 14 having high rigidity instead of a screw shaft for generating a driving force. Further, a guide member for guiding the sliding of the slider 30 which is a movable part is provided so that an eccentric load does not act on the part of the screw 32b. As a result, it is not necessary to provide the hook 22 directly below (on the extension line) of the drive shaft DA, which leads to solving the problem that "it is difficult to aim at the nail" by offsetting the arrangement of the hook 22.

[0052] <Offset arrangement of the hook> The hook 22 of the hook member 20 is arranged at a position offset from the drive shaft DA (see FIG. 10A etc.). The hook 22 of the hook member 20 of the present embodiment is formed so as to project in a direction perpendicular to the drive shaft DA and faces the horizontal direction in the use state (see FIG. 6A etc.). Further, at least a part of the hook 22 is provided outside the cover 50 so as to be visible (see FIG. 5 etc.). The advantages of the configuration as described above are as follows. That is, in some conventional charging nail pullers, the hook 22' is arranged at a position directly below a screw shaft 72' such as a ball screw (in other words, on the extension line of the drive shaft DA) (see FIGS. 30A and 30B). However, in this case, since the hook 22' is difficult to see and its position is difficult to grasp, it may be difficult to perform the operation of hanging the hook 22' on the nail head Ph. In this regard, according to the charging nail puller 1 in which the hook 22 is offset as in the present embodiment, the hook 22 is more visible to the user because it is offset from the drive shaft DA, and the operation of hanging the hook 22 on the nail head Ph is easy to perform (see FIGS. 7A and 7B etc.).

[0053] <Projecting leg portion at the tip of the slider> Further, in the present embodiment, along with the offset arrangement of the hook 22 as described above, the slider 30, particularly its tip portion 31, has a structure suitable for the offset arrangement of the hook 22. That is, (1) A protruding leg portion 35 that protrudes in a direction perpendicular to the drive shaft DA is provided at the tip portion 31 of the slider 30 (see FIG. 10A etc.). The protruding leg portion 35 is formed to have a size and shape sufficient to eliminate the influence of an external force (moment) that can act when pulling out the nail P with the offset hook 22. As a preferred example, in the present embodiment, the size is sufficiently protruding compared to the hook 22 (see FIG. 19A etc.), and a pair of protruding leg portions 35 having a symmetrically arranged shape are provided at the tip portion 31 (see FIG. 5 etc.). The length from the drive shaft DA to the tip of the hook 22 is L4, and the protruding leg portion 35 is further forward by a length L5 than that (see FIG. 19B). The pair of protruding leg portions 35 are arranged at an interval wider than the hook 22 so that the hook 22 of the hook member 20 can be positioned therebetween (see FIG. 7B etc.). (2) A flat surface 31f that abuts against the concrete panel Q, the crossbar R, etc. is formed at the tip portion 31 of the slider 30 (see FIG. 19A etc.). This flat surface 31f is at least sized or shaped sufficiently to eliminate the influence of an external force (moment) that can act when pulling out the nail P with the offset hook 22. In the present embodiment, a flat surface 31f that extends further forward beyond the offset amount Los of the hook 22 (in this specification, the distance between the virtual central axis Pc and the drive shaft DA when the nail P hung on the hook 22 is assumed to be straight) is formed (in other words, the length L3 from the drive shaft DA to the front end of the flat surface 31f is sufficiently long compared to the offset amount Los), and the contact area (ground contact area) with the concrete panel Q, the crossbar R, etc. is widened (see FIG. 19B etc.). Needless to say, the lower surface of the above-described protruding leg portion 35 may be entirely or mostly flat.

[0054] <Rotating structure of hook etc.> When the hook 22 is offset and protrudes in a direction perpendicular to the drive shaft DA as described above, it is preferable that the hook 22 be rotatable (swingable) around the drive shaft DA. By doing so, it is possible to reduce the operational constraints such as always having to use the charging nail puller 1 in a fixed direction as in the case where the hook 22 always faces one direction, and further improve the ease of handling (see FIGS. 20A, 20B, etc.). In the present embodiment, a rotatable portion 21 and an O-ring 26 are provided at the lower tip portion of the hook member 20 so that the direction of the hook 22 formed on the rotatable portion 21 can be changed (see FIGS. 21A, 21B, 22A, etc.). The specific configuration of the rotatable portion 21 is not particularly limited. As an example, in the present embodiment, an annular rotatable portion 21 having a larger diameter than the cylindrical portion 23 is provided at the lower tip portion of the cylindrical portion (indicated by reference numeral 23) of the hook member 20, and the direction of the hook 22 can be changed by manually rotating the rotatable portion 21 around the drive shaft DA (see FIGS. 22A, 23B, etc.).

[0055] The O-ring 26 is, for example, a rubber annular member provided between the rotatable portion 21 and the cylindrical portion 23 (see FIGS. 23B, etc.). This O-ring 26 functions as a resistor that imparts a predetermined resistance to the rotational movement of the rotatable portion 21 around the drive shaft DA, and while allowing relative rotation of the rotatable portion 21, suppresses the rotatable portion 21 from unexpectedly rotating after the direction of the hook 22 is changed.

[0056] In the charging nail puller 1 of the present embodiment, not only the hook 22 but also the direction of the protruding leg portion 35 of the slider 30 can be changed. For example, in the present embodiment, the rod portion 32 and the tip portion 31 of the slider 30 are separated, and a rotatable portion 34 that allows relative rotation and further an O-ring 38 are provided therebetween, so that the tip portion 31, the side cover portion 33, and the protruding leg portion 35 are integrated and can rotate (swing) relative to the rod portion 32 (see FIGS. 24B, etc.). The rotatable portion 34 can be configured, for example, by a screw that rotatably attaches the tip portion 31 to the lower end portion of the rod portion 32 (see FIGS. 24B, etc.).

[0057] The O-ring 38 is an annular member made of, for example, rubber provided between the rod portion 32 and the tip portion 31 (see FIG. 24B etc.). This O-ring 38 functions as a resistor that imparts a predetermined resistance to the rotational movement around the drive shaft DA such as the tip portion 31, and while allowing relative rotation of the tip portion 31 etc., it suppresses the sudden rotation of the protruding leg portion 35 or the tip portion 31 after changing the direction of the protruding leg portion 35.

[0058] Also, in the present embodiment, in a state where the slider 30 is in the initial position retracted into the main body portion 10, the protruding leg portion 35 and the hook 22 are formed so that at least a part of them overlaps with each other in the axial direction of the drive shaft DA (see FIG. 23B etc.). In other words, this means that if the protruding leg portion 35 is rotated in the retracted state (initial position), it will interfere with the hook 22 during rotation. Therefore, in the nail extractor 1 of the present embodiment, if the protruding leg portion 35 is rotated in the retracted state (initial position), the hook 22 can be rotated by the same amount. For example, when it is desired to change the direction of the hook 22 according to the position and form of the nail P etc., it is convenient because the direction can be changed simultaneously with the hook 22 by rotating the outer protruding leg portion 35 (see FIGS. 22A, 22B etc.). Also, the fact that the protruding leg portion 35 and the hook 22 always face the same direction means that when pulling out the nail P, the protruding leg portion 35 is always at a position directly below the hook 22 (see FIGS. 24A, 24B etc.). Therefore, no matter which direction the hook 22 is directed, the external force (moment) that can act when pulling out the nail P with the offset hook 22 is received by the protruding leg portion 35 directly below, and the influence can be eliminated.

[0059] <Structure for returning the directions of the hook and the protruding leg portion> Furthermore, in this embodiment, even if the nail-pulling operation is performed by changing the directions of the hook 22 and the protruding leg portion 35, after the operation, a mechanism that returns the directions of the hook 22 and the protruding leg portion 35 to their original positions (facing forward in this embodiment) is operative (see FIGS. 22A, 23A, etc.). Such a mechanism is, for example, a device including a guide member that rotates the hook 22 and the protruding leg portion 35 by a predetermined amount so as to face forward while guiding the rotatable portion 21 of the slider 30 and the hook member 20 from a state where the slider 30 protrudes from the main body portion 10 the most to pull out the nail P (protruding state) (see FIGS. 24B, 24C, etc.) until it returns to the initial position where it is in the retracted state (see FIGS. 23B, etc.). (For example, it is composed of a combination of a spiral guide and a protrusion guided along the guide, and is a device that defines the circumferential position of the protruding leg portion 35 of the slider 30 and the rotatable portion 21 of the hook member 20 along with the pulling-up sliding operation when the slider 30 returns to the initial position), etc.

[0060] <Structure for clamping members> The charging nail puller 1 provided with the hook 22 and the protruding leg portion 35 as described above is mainly used for pulling out nails, but can also be used as a clamping device for clamping a member arranged perpendicular to the drive shaft DA. For example, when two concrete panels Q are brought closer by clamping the crossbars of the concrete panel Q and the concrete panels Q are brought into contact with no gap, these crossbars R can be sandwiched between the lower surface of the hook 22 and the upper surface of the protruding leg portion 35 (see FIGS. 29A, 29B). The hook 22 and the protruding leg portion 35 when used for such applications can be said to function as a holding portion that sandwiches and holds the member to be clamped.

[0061] According to the charging nail puller 1 of this embodiment, although it is a single power tool, it enables practical usage other than nail pulling. This also makes it possible to meet the potential needs at the site where it is often considered costly and troublesome to prepare different tools for each operation.

[0062] [Third Embodiment] As a third embodiment of the present invention, a charging nail puller 1 that can also be used for demolition work applications such as concrete panels Q and crossbars R and has further improved convenience will be described. In this charging nail puller 1, a tapered pointed portion is formed at a part of the slider 30. By hitting the slider 30 with a hammer or the like and driving the pointed portion in, separation work of plate materials or frame materials such as concrete panels Q and crossbars R can be easily performed (see FIG. 25A, etc.).

[0063] <Structure suitable for demolition work applications such as plate materials> In this embodiment, a tapered portion 36 is formed at a part of the protruding leg portion 35 of the slider 30 (see FIG. 25A, etc.). The tapered portion 36 is a tapered portion formed in a wedge shape so as to face the direction away from the drive shaft DA. For example, in this embodiment, it is formed so as to face the direction perpendicular to the drive shaft DA at a portion facing forward in the retracted state of the initial position of the charging nail puller 1 (see FIG. 25A, etc.). The shape of the tapered portion 36 is not particularly limited as long as it is tapered. Both the upper surface 36t and the lower surface 36b may be inclined surfaces as in this embodiment (see FIG. 25C, etc.), or only one of them may be an inclined surface and the other surface may be a horizontal surface in the use state. Also, the upper surface 36t and the lower surface 36b may be flat surfaces or gently curved surfaces. In short, when the slider 30 is hit and the tapered portion 36 is driven in, it should have a wedge shape that exerts a force to separate plate materials or frame materials such as concrete panels Q and crossbars R.

[0064] In this embodiment, the tapered portions 36 are provided at the tip ends of a pair of left and right protruding leg portions 35 and are formed in a symmetric shape about a virtual plane (indicated by the reference sign VP in FIG. 4) including the drive shaft DA. Also, the left and right tapered portions 36 are separated from each other so that the hook of the hook member 20 can fit between them (see FIG. 7B, etc.).

[0065] Of the slider 30, a struck portion 37 is formed on the side opposite to the tapered portion 36 (the rear side in the use state) with respect to the drive shaft DA (see FIG. 25B etc.). In the present embodiment, the struck portion 37 is formed in a shape that protrudes toward the side opposite to the tapered portion 36 with respect to the drive shaft DA, thereby clearly showing the user the location to be struck by the hammer 300 and preventing the hammer 300 from striking the cover 50 etc. of the nail charger 1 during the strike (see FIG. 26 etc.). Especially considering the latter point, the slider 30 may be formed such that the struck portion 37 protrudes sufficiently more than the surface of the cover 50 (see FIG. 25C etc.).

[0066] At least the portion of the slider 30 used for the striking operation (the portion including the tapered portion 36 and the struck portion 37) is made of a material having rigidity capable of withstanding strikes. This portion may be made of metal such as a casting, for example. Alternatively, this portion may be constituted by a detachable attachment (indicated by reference numeral 40 in FIG. 25B). When a detachable attachment 40 provided with the tapered portion 36 and the struck portion 37 is adopted, even if the tapered portion 36 and the struck portion 37 are damaged, they can be easily replaced. The entire attachment 40 may be made of metal such as a casting. The attachment 40 may be rotatably provided around the drive shaft DA with respect to the rod portion 32 etc. of the slider 30.

[0067] Also, in the present embodiment, the tapered portion 36 formed on the slider 30 as described above is sized such that its tip 36a is located outside the hook 22 of the hook member 20 (in other words, at a position farther from the drive shaft DA), and the outline of the tapered portion 36 is laid out outside the outline of the hook 22 (in other words, the shape in which the hook 22 is hidden within the projection plane of the protruding leg portion 35 or its tapered portion 36 when viewed from the side) (see FIG. 25C etc.). By thus forming the tapered portion 36 larger than the hook 22 and positioning it forward, when the tapered portion 36 is inserted into the gap between the concrete panel Q and the crossbar R, for example, it is possible to avoid the hook 22 from becoming a resistance.

[0068] According to the charging nail puller 1 as described above, by inserting the tapered portion 36 into the gap between, for example, the concrete panel Q and the crossbar R and hitting the struck portion 37 with the hammer 300, the gap between the concrete panel Q and the crossbar R can be widened using the striking force in the same manner as when using a burr (see FIG. 26 and the like). If the slider 30 is slid with the hook 22 and the protruding leg portion 35 inserted deeply in this way, the gap between the concrete panel Q and the crossbar R can be further widened to a state where it is easy to separate (see FIGS. 27A, 27B, 27C, etc.). Further, in a situation where the nail head Ph is slightly floating from the concrete panel Q, the crossbar R, etc., but is firmly penetrated and it is difficult to hook the hook 22 on the nail head Ph, in that state, the struck portion 37 is hit with the hammer 300 and the hook member 20 is pushed forward little by little to bring the hook 22 into a state where it is sufficiently engaged with the nail head Ph. It is possible to use it in such a way.

[0069] <Usage for lifting a nail from a plate material or the like> The charging nail puller 1 having the configuration described so far can also be used to lift the nail P stuck in a plate material or a frame material such as the concrete panel Q or the crossbar R (see FIG. 28A and the like).

[0070] When considering the demolition work to be carried out after the concrete has hardened for the nails P driven during the formwork panel work, the nail heads Ph are often driven in a state where they are raised. However, even so, there may be cases where the floating width is not sufficient and it is difficult to hook the hook 22. Therefore, it is convenient to keep such nails P in a further raised state. In this case, the rechargeable nail puller 1 can be used to further raise the nails P. Specifically, for example, when a nail P remains stuck in a concrete panel Q separated from a cross member (see Fig. 28E(a)), first, a pressing tool 400 is provided in advance between a pair of left and right hooks 22. The protruding leg portion 35 is applied to the surface of the concrete panel Q (the surface with the nail head Ph) in a protruding state where the slider 30 is slid, and the nail leg Pt is pushed down with the pressing tool 400 (see Figs. 28A, 28B, 28C, 28D, 28E(b)). When the nail head Ph floats from the surface of the concrete panel Q (see Fig. 28E(c)), if the nail P is pulled out with the rechargeable nail puller 1 (see Fig. 28E(d)), smooth and efficient work may be possible. The pressing tool 400 may be any tool that can push down the tip of the nail leg Pt, and a jig that is detachable from the hook 22 can be used, etc.

[0071] According to the rechargeable nail puller 1 of the present embodiment, although it is a single power tool, it enables practical usage other than nail pulling. This also makes it possible to meet the potential needs at the site, which are often considered costly and troublesome to prepare different tools for each operation.

[0072] [Fourth Embodiment] As the fourth embodiment of the present invention, various operations of the rechargeable nail puller 1 and its control will be described (see Figs. 31, 32A, etc.).

[0073] <Control Device> The control device 90 causes the slider (sliding member) 30 to perform a predetermined operation by the motor (drive source) 60 in response to a trigger signal input from the outside.

[0074] <Home Sensor> The origin sensor 80 is provided as a means for detecting that the slider 30 is in the initial position. The origin sensor 80 may be an optical sensor or the like that detects the position on the drive shaft DA of the slider 30. Alternatively, the origin sensor 80 may be configured to grasp the position or the amount of movement of the slider 30 based on the rotation amount of the motor 60. Or, the origin sensor 80 may be composed of a switch arranged so as to detect that the slider 30 is in a predetermined position when it comes into contact with the slider 30.

[0075] <Operation mode> The charging nail puller 1 of the present embodiment is set with a plurality of selectable operation modes for operating the slider 30 according to the content of the work on the work target. The operation mode is various ways of operation set so that the user can select according to the way the charging nail puller 1 moves during nail pulling or the mode and desired operation during uses other than nail pulling. In the charging nail puller 1 of the present embodiment, a "nail pulling mode", a "one-cycle nail pulling mode", and further a "clamping mode" that can be selected by the user by operating a mode operation / display unit (indicated by reference numeral 92 in FIG. 31) for operating the mode are set.

[0076] <Operation flow of nail pulling> An example of the operation flow when controlling the nail pulling operation in the charging nail puller 1 will be described (see FIGS. 34 and 35).

[0077] After turning on the main power supply (step SP301), select the operation mode (step SP303). As the operation modes for nail pulling applications, a "nail pulling mode" and a "one-cycle nail pulling mode" that can be selected by the user by operating a mode selection switch (not shown) are set so that the user can select according to the mode of nail pulling and the desired operation of the charging nail puller 1 during nail pulling.

[0078] <Operation flow of nail pulling (nail pulling mode)> When the "nail extraction mode" is selected in step SP303, first, the operation of driving to the initial position is performed (step SP311). This is a series of automatic operations for detecting the position of the driving part of the slider 30 as described above and moving the position of the slider 30 to a predetermined initial position. When a mode change is instructed, the slider 30 moves to a different initial position for each mode, but this step may be skipped if there is no mode change.

[0079] After the operation of driving to the initial position (step SP311), the setting of the operation amount is reflected (step SP312). This step is for appropriately setting the operation amount (sliding length) of the slider 30 during the nail extraction operation to be performed hereafter. For example, it may be provided so that it can be switched by operating a switch (not shown) that can be operated or input by the user. The switch in the case of adopting a switch may be a tact switch, a dial switch, or the like, anything is acceptable. Although detailed description is omitted, "Auto" for automatically setting the operation amount, "Standard" for setting a standard operation amount, etc. may be selectable. The operation amount (sliding length) of the slider 30 may be controlled based on the rotation amount of a motor (for example, a stepping motor) 60. In this case, the rotation amount of the motor 60 may be set in advance in the control device.

[0080] While the trigger OFF signal is input, SP303, SP311, SP312, and SP313 are continuously executed. When the trigger becomes ON, the nail extraction operation is started (step SP314).

[0081] In the steps of the nail extraction operation, the motor 60 is driven forward to move the slider 30 in the direction of protruding from the main body 10 (that is, the nail pulling-out operation direction described above) (step SP314). When the operation amount of the slider 30 reaches a preset operation amount (step SP312) (step SP315), the motor 60 is stopped and the driving of the slider 30 is stopped (step SP316). After the driving of the slider 30 is stopped, wait until the trigger is turned off (step SP317). That is, wait from the state where the trigger switch 122 is being pulled by the user's finger (trigger ON state) until the finger is released (or the force pulling the switch is relaxed) and the trigger switch 122 returns to its original state (trigger OFF state). When the trigger signal becomes off (that is, when the trigger is in the OFF state), the motor 60 is reversed to move the slider 30 in the direction of returning to the initial position (the direction of being drawn into the main body 10) (step SP318). When the slider 30 returns and reaches the initial position (step SP319), the driving of the motor 60 and the slider 30 is stopped (step SP320), and a series of operations (nail extraction mode) are terminated. After a series of operations are completed, return to step SP303, prepare for the next nail extraction operation, and perform the same operations as above according to the input (see FIG. 34). As described above, in the nail extraction mode, when the trigger signal is turned on, the slider 30 is slid by a preset predetermined length, etc., and a predetermined operation is performed on the slider 30 according to the trigger signal input from the outside.

[0082] <Nail Extraction Operation Flow (One-Cycle Nail Extraction Mode)> The operation flow when "one-cycle nail extraction mode" is selected in step SP303 will be described (see Fig. 35 etc.). In the "one-cycle nail extraction mode", the operation of driving to the initial position is performed (step SP321), and then the operation amount setting (step SP322), trigger ON waiting (step SP323), nail extraction operation (step SP324), reaching the set operation amount (step SP325), and driving stop (step SP326) are sequentially performed (see Fig. 35). Each operation up to this point is the same as that in steps SP311 to SP316 in the above-mentioned "nail extraction mode" (see Figs. 34 and 35).

[0083] After this, in the one-cycle nail extraction mode, regardless of the state of the trigger switch 122 (trigger ON or trigger OFF), the motor 60 is reversed to move the slider 30 in the direction of returning to the initial position (step SP327), and it is not held in the protruding state. When the slider 30 returns and reaches the initial position (step SP328), the driving of the motor 60 and the slider 30 is stopped (step SP329). After the driving stop, wait until the trigger becomes OFF (step SP330). When the trigger switch 122 returns from the state where it is being pulled by the user's finger (trigger ON state) to the original state (trigger OFF state), return to step SP303 to prepare for the next nail extraction operation (see Figs. 34 and 35). As described above, in the one-cycle nail extraction mode, when the trigger signal becomes ON, the slider 30 is slid by a predetermined length set in advance, and then the operation of returning to the initial position is performed.

[0084] <Operation flow of nail extraction + clamp> The charging nail extractor 1 may also be able to perform a clamp operation in addition to the nail extraction operation. An example of the operation flow when both the nail extraction operation and the clamp operation can be performed will be described (see Figs. 36A to 36C).

[0085] After the main power is turned on (step SP501), select any one of the operating modes from "nail extraction mode", "one-cycle nail extraction mode", and "clamp mode" (step SP503). The operation flow when the "nail extraction mode" is selected (steps SP511 to SP520, see Fig. 36A) is the same as that in the above-mentioned "nail extraction mode" (see Fig. 34), and the operation flow when the "one-cycle nail extraction mode" is selected (steps SP521 to SP530, see Fig. 36B) is the same as that in the above-mentioned "one-cycle nail extraction mode" (see Fig. 35), so it will not be described here. An example of the operation flow when the "clamp mode" is selected will be described below (see Fig. 36C).

[0086] <Operation flow of the clamp (clamp mode)> When "Clamp Mode" is selected in step SP503, the motor 60 is driven forward to drive the slider 30 to the position where it protrudes most from the main body 10 (hereinafter also referred to as the "fully extended position") (step SP531), and waits until the trigger switch 122 is pulled and a "Trigger ON" signal is transmitted (step SP532). When the trigger is turned ON, the motor 60 is reversed to start the clamping operation (the operation of clamping the work object such as the crossbars of the concrete panel Q between the hook 22 and the protruding leg 35) (step SP533). After the start of the clamping operation, if a predetermined load (clamping load) is generated before the slider 30 reaches the initial position (NO in step SP534, YES in step SP535), the driving of the motor 60 and the slider 30 is stopped at that time (step SP536), and it waits until the trigger is turned OFF while maintaining the state of clamping the work object (step SP537). That is, it waits from the state where the trigger switch 122 is being pulled by the user's finger (the trigger ON state) until the finger is released (or the force pulling the switch is relaxed) and the trigger switch 122 returns to the original state (the trigger OFF state), and when the trigger OFF state is reached, it waits until the trigger switch 122 is pulled and the trigger ON state is reached (step SP538). When the trigger is turned ON here, the motor 60 is rotated forward again to drive the slider 30 back to the fully extended position (step SP540). When the slider 30 reaches the fully extended position (step SP541), the driving of the motor 60 and the slider 30 is stopped (step SP542). After that, it waits until the trigger is turned OFF (step SP543), and when the trigger is turned OFF, it returns to the step of selecting the operation mode (step SP503).

[0087] Also, if the slider 30 reaches the initial position in step SP534 (YES in step SP534), it is determined that the work object etc. was not clamped while the slider 30 moved from the fully extended position to the initial position, and the process transitions to step SP539 to stop the driving (see FIG. 36C).

[0088] During the operation of the slider 30, the load acting on the slider 30 and the motor 60 can be detected based on the current value of the motor 60. Here, for reference, an example of the current waveform of the motor 60 when the motor 60 is reversely driven during the clamp mode is shown (see Fig. 37). The current value when the work object is clamped is larger than the current value when the motor 60 is reversely driven during the nail pulling mode (specifically, when returning the slider 30 to the initial position (step SP518) after the nail pulling operation (see Fig. 36A)). Therefore, when the threshold current C1 during the reverse drive in the nail pulling mode is set, by setting a value C2 larger than the current C1 as the threshold current during the reverse drive in the clamp mode, it is possible to detect that the clamp operation has been completed based on the threshold current C2 (see Fig. 37).

[0089] <Operation flow of initial position detection (in the case of sensorless)> Next, the operation flow of positioning the slider 30 and the like at the initial position in accordance with the trigger signal in the rechargeable nail puller 1 will be described. Here, in the rechargeable nail puller 1 configured without a sensor for detecting the position of the slider 30, that is, sensorless, three types of patterns will be described: pattern 1 without room for member clamping, pattern 2 with room for member clamping and normal termination, and pattern 3 with member clamping and abnormal termination (see Figs. 32A to 32D). Note that the flowcharts representing the operations of the three types of patterns 1 to 3 are as shown in Fig. 32A. Also, in Figs. 32B to 32D, any part of the slider 30 is taken as the "operating part", and the movement and the amount thereof of the slider 30 are shown while indicating the part with a hollow triangle symbol. It should be noted that the movement of the slider 30 relative to the main body 10 of the rechargeable nail puller 1 (sliding downward (see Fig. 7B etc.)) is represented as the movement in the right direction (nail pulling operation direction) in the figures in Figs. 32B to 32D. Also, related parts between the operations in the flowchart (see Fig. 32A) and the operations in each pattern (see Figs. 32B to 32D) are marked with the same number in parentheses in the figures.

[0090] <Initial position detection (sensorless case) operation flow (pattern 1)> In the nail extractor 1, when the main power is turned on (step SP101), using this as the initial trigger, the operation flow for detecting the initial position of the slider 30 starts (see FIGS. 32A and 32B). When the trigger signal is turned on and the flow starts in this way, first, the motor 60 is driven in reverse (step SP110), and it is determined whether a high load (a load higher than a predetermined value) is detected in a state where the slider 30 hits a position where it can no longer slide (hereinafter referred to as the "reverse side limit position") (step SP111). If a high load is detected (YES in step SP111), the motor 60 is driven forward (step SP141), and it is determined whether the slider 30 has moved a predetermined amount corresponding to the initial position setting specified amount X0 (step SP142).

[0091] Here, the "initial position setting specified amount X0" refers to an amount corresponding to the difference between the "target initial position W0" where the slider 30 should be located at the beginning of operation and the above-mentioned "reverse side limit position W1" (see FIG. 32B). In the present embodiment, a method is adopted in which the slider 30 is first pulled back to the reverse side limit position W1, and then the slider 30 is positioned at the target initial position W0 (the position of the slider 30 is set) by sliding by a predetermined length corresponding to the initial position setting specified amount X0. Specifically, when it is detected that the slider 30 has moved from the "reverse side limit position W1" by the "initial position setting specified amount X0" (YES in step SP142), it is assumed that the slider 30 has reached the "target initial position W0", the motor 60 is stopped (step SP143), a series of initial position detection operations are completed (step SP144), and the process proceeds to normal control (control associated with operations such as nail extraction) (step SP150).

[0092] <Initial position detection (sensorless case) operation flow (pattern 2)> In pattern 2 shown below, the operation flow in the case where there is room for pinching of some member during the operation of the slider 30 associated with the initial position detection will be described (see FIGS. 32A and 32C, etc.).

[0093] Steps SP101 to SP111 are the same as the above Pattern 1 (see Fig. 32A). In step SP111, if "high load is not detected in the state of hitting the reverse-side limit position W1" (NO in step SP111), it is determined whether the operating part has moved by a specified amount X1 (whether it has entered the main body part 10) (step SP121). The specified amount X1 mentioned here is different from the above-described initial positioning specified amount X0. Until the moving amount of the operating part reaches this specified amount X1, the flow returning to step SP111 is repeated (NO in step SP121). When the moving amount of the operating part reaches the specified amount X1 (YES in step SP121), the motor 60 is rotated forward (step SP122), the slider 30 is moved in the direction of protruding from the main body part 10, and it is determined whether a high load is detected at the forward-side limit position W2 (step SP123). The forward-side limit position W2 mentioned here is a position where the slider 30 can no longer slide in the protruding direction (see Fig. 32C), and is the end of the stroke possible width of the slider 30. Here, it waits until a high load exceeding a predetermined value is detected, and when detected, it is determined that the slider 30 has reached the forward-side limit position W2 and proceeds to step SP124 (see Fig. 32A).

[0094] In step SP124, the motor 60 is rotated in reverse, and the slider 30 is moved in the direction of being drawn into the main body part 10. Then, it is determined whether a high load is detected at the reverse-side limit position W1 (step SP125). Here, it waits until a high load exceeding a predetermined value is detected, and when detected, it is determined that the slider 30 has reached the reverse-side limit position W1.

[0095] Subsequently, it is determined whether the slider 30 has moved by more than the abnormal prevention specified amount X ap above (step SP126). The abnormal prevention specified amount X apis an amount set as an index for determining that no abnormality such as the slider 30 getting caught on something or pinching a foreign object occurs during the movement of the slider 30 (in this embodiment, moving from the forward rotation side limit position W2 to the reverse rotation side limit position W1). For example, it is set as an amount occupying a predetermined ratio of the stroke - possible width of the slider 30 (see FIG. 32C). When the slider 30 moves more than the abnormality - prevention regulated amount X in this step SP126 ap in the above - described series of operations up to this point, it is determined that no abnormality has been confirmed, and the process proceeds to the above - described step SP141. After step SP141, the same operations as in the above - described pattern 1 are performed (steps SP141 to SP144, step SP150). On the other hand, when the slider 30 does not move more than the abnormality - prevention regulated amount X in step SP126 ap the process proceeds to step SP131 (see FIG. 32A). Step SP131 will be described in the following pattern 3

[0096] <Operation flow of initial position detection (in the case of sensorless) (Pattern 3)> In the following pattern 3, mainly, the flow when the slider 30 does not move more than the abnormality - prevention regulated amount X in the above - described step SP126 will be explained (see FIGS. 32A, 32D, etc.). When the slider 30 does not move more than the abnormality - prevention regulated amount X in this step SP126 ap it is determined that an abnormal lock has occurred due to an event such as the slider 30 getting caught on something or pinching a foreign object during the movement from the forward rotation side limit position W2 to the reverse rotation side limit position W1 (step SP131). In this case, the operation flow of the initial position detection is terminated. Also, the occurrence of the abnormal lock may be notified to the user by lighting a lamp provided on the main body 10 of the charging nail - pulling machine 1 or sounding a buzzer ap

[0097] <Operation flow of initial position detection (in the case of having a sensor)> ​Next, another form of the operation flow for positioning the slider 30 and the like at the initial position in accordance with the trigger signal in the charging nail puller 1 will be described. In the following, in the charging nail puller 1 provided with the position detection sensor, the "operating part position < origin position W op ", the detection is started in pattern 1, "origin position W op < operating part position", the detection is started in pattern 2, "operating part position = origin position W op ", the detection is started in pattern 3, will be described (see FIGS. 33A to 33D). Note that the flowcharts representing the operations of the three types of patterns 1 to 3 are as shown in FIG. 33A. The "operating part" is as described in the above embodiment. Also, the "origin position" here refers to the position or range where the "operating part" should be when the slider 30 is in the initial position. In the present embodiment, as the detection sensor, a sensor (for example, the origin sensor indicated by reference numeral 80 in FIG. 31) for detecting whether the operating part is at the origin position W op is used for position detection. Although specific examples of what is assumed to be used as the detection sensor are not limited, one example is a non-contact Hall IC that detects a magnet attached to the slider 30.

[0098] In the charging nail puller 1, when the main power supply is turned on (step SP201), the operation flow for detecting the initial position of the slider 30 starts with this as the first trigger (see FIGS. 33A and 33B). When the trigger signal is turned on and the flow starts in this way, the state of the origin sensor is checked, and it is determined whether the origin sensor has detected the operating part of the slider 30 or is in a non-detection state (step SP203). If it is in a non-detection state, first, the operation flow proceeds according to pattern 1 (see FIG. 33A).

[0099] <Operation flow of initial position detection (when there is a sensor) (Pattern 1)> In Pattern 1, first, the motor 60 is driven to rotate forward (step SP211), and the slider 30 is moved in the direction of protruding from the main body 10 (the direction of the nail pulling-out operation) (see Fig. 33A). After that, it waits to see if the origin sensor detects the operating part (step SP212). If detected, it proceeds to step SP213. On the other hand, if the operating part of the slider 30 has moved a specified amount without being detected, it proceeds according to the operation flow of Pattern 2 described later.

[0100] When the origin sensor detects the operating part (step SP212), this time it waits until the origin sensor no longer detects the operating part (step SP213). When the slider 30 is moved to a non-detected state, it is determined that the slider 30 has moved past the origin position W op (see Fig. 33B). At this point, the motor 60 is reversed (step SP214), and the slider 30 is moved in the direction of pulling it back. After that, when the origin sensor detects the operating part (step SP215), it is determined that the operating part that has passed the origin position W op has returned to the origin position W op again. In this embodiment, after the motor 60 is once stopped (step SP241), a series of initial position detection operations are completed in this state (step SP242), and then it shifts to normal control (control associated with operations such as nail pulling) (step SP250).

[0101] <Operation flow of initial position detection (when there is a sensor) (Pattern 2)> The above Pattern 1 corresponds to the case where at the time of turning on the main power (first trigger), "operating part position < origin position W op " (the origin position W op is located in the nail pulling-out operation direction relative to the operating part). However, during the operation flow, if it is found that at the time of the first trigger, actually it is the opposite "origin position W op < operating part position" (the operating part is located in the nail pulling-out operation direction relative to the origin position W op ), then it proceeds with the operation flow of Pattern 2 described below (see Figs. 33A and 33C).

[0102] That is, after the motor rotates forward (step SP211), in step SP212 where it waits to see if the home sensor detects the operating part, if the operating part of the slider 30 moves by a specified amount X2 without being detected (see Fig. 33C), the motor 60 is reversed (step SP222) to move the slider 30 in the direction of pulling it back. After that, when the home sensor detects the operating part (step SP223), the operating part that was originally at the "home position W op <operating part position" is determined to be located at the home position W op After determining that it is located at the home position W, the motor 60 is stopped (step SP241), and after completing a series of initial position detection operations (step SP242), the process proceeds to normal control (step SP250).

[0103] <Operation flow of initial position detection (when there is a sensor) (Pattern 3)> After the main power is turned on (step SP201), when the home sensor detects the operating part of the slider 30 (the "operating part position = home position W op "), the operation flow proceeds according to Pattern 3 (see Figs. 33A and 33D). In Pattern 3, first, the motor 60 is rotated forward (step SP231) to move the slider 30 in the direction of protruding from the main body 10 (the direction of the nail pulling-out operation), and it waits until the home sensor is in a non-detection state (step SP232). When it becomes a non-detection state, the motor 60 is reversed (step SP233) to move the slider 30 in the direction of pulling it back. After that, it waits until the home sensor detects the operating part (step SP234). When the home sensor detects the operating part, it is determined that the operating part that has passed the home position W op has returned to the home position W op again. After stopping the motor 60 (step SP241), a series of initial position detection operations are completed in that state (step SP242), and the process proceeds to normal control (step SP250).

[0104] <Operation flow of nail pulling + initial position detection + clamp> An initial position detection operation after the trigger is turned on may be added to the above-described nail pulling + clamping operation. An example of the operation flow in this case will be described (see FIGS. 38A to 38C). In the following, the description will focus on the points different from the above-described nail pulling + clamping operation flow (see FIGS. 36A to 36C).

[0105] In this operation flow, after the main power is turned on (step SP601), the initial position of the slider 30 is detected (step SP602). For the initial position detection, if it is a sensorless case, the detection operation is performed as in the above-described "operation flow of initial position detection (in the case of sensorless)" (see FIGS. 32A to 32D), and if there is a sensor, the detection operation is performed as in the above-described "operation flow of initial position detection (in the case of having a sensor)" (see FIGS. 33A to 33D). After that, similar to the above-described "nail pulling + clamping operation flow" (see FIGS. 36A to 36C), a nail pulling operation or a clamping operation is performed (see FIGS. 38A to 38C).

[0106] Note that the above-described embodiment is a preferred example of the present invention, but it is not limited thereto, and various modifications can be made without departing from the gist of the present invention. For example, in the above-described embodiment, a structure in which the hook member 20 (hook 22 thereof) is relatively operated by sliding only the slider 30 (a structure in which the hook 22 is relatively fixed to the main body 10) has been described, but a structure in which both the slider 30 and the hook member 20 are operated simultaneously may be used. Although not particularly illustrated here, for example, a configuration in which the slider 30 and the hook member 20 are interlocked using a rack and pinion mechanism or the like may be used, or the hook member 20 may be configured to slide in the opposite direction by an interlocking mechanism that interlocks with the movement of the slider 30 protruding.

[0107] In the above-described embodiment, the charging nail puller 1 using the motor 60 as a drive source has been described (see FIG. 6B and the like), but this is merely an example of a suitable configuration. Although not particularly illustrated, in addition to the electric nail puller using a motor as a drive source, various power-driven nail pullers such as a compressed air nail puller using an air motor and a hydraulic nail puller using a hydraulic motor, or various electric tools using an AC electric motor as a drive source can be configured. Alternatively, a configuration may be adopted in which the slider 30 is driven by an air cylinder, or a drive mechanism 70 using a trapezoidal screw instead of the ball screw 73 may be configured. Alternatively, a configuration may be adopted in which a rack and pinion, a worm gear, or the like is used to convert the rotation of the motor 60 into a linear motion.

Industrial Applicability

[0108] The present invention is suitable for application to various power tools including electric nail pullers.

Explanation of Signs

[0109] 1... Charging nail puller (power tool) 10... Main body 11... Mechanism 12... Hand grip (grip part) 13... Battery housing 13S... Mounting surface 14... Main frame (guide member) 15... Frame base 20... Hook member (engagement member, guide member) 21... Rotatable part of hook member (rotatable part of engagement member) 22... Hook (engagement part) 22’... Hook 23... Cylindrical part 24... Fastening screw 26... O-ring (resistor) 30... Slider (sliding member) 31... Tip of slider (tip of sliding member) 31f... Flat surface (Contact part) 32... Rod part of slider 32a… Flange part 32b… Female screw 32c… Sleeve part 33… Side cover part of the slider 34… Rotatable part of the slider (rotatable part of the sliding member) 35… Projecting leg part of the slider (holding part) 36… Taper part of the projecting leg part of the slider (pointed part) 36a… Tip of the taper part (tip of the pointed part) 36b… Lower surface of the taper part 36t… Upper surface of the taper part 37… Struck part 38… O-ring (resistor) 40… Attachment of the slider 50… Cover 60… Motor (driving source) 66… Battery 70… Driving mechanism 71… Reducer (part of the driving mechanism) 72… Screw shaft 72’… Screw shaft 73… Ball screw (part of the driving mechanism) 80… Home sensor (sensor for detecting the position of the slider) 90… Control device 92… Mode operation and display part 122… Trigger switch 132… Strap 134… Belt hook 300… Hammer 400… Pusher C1… Threshold current during reverse drive in the nail-pulling mode C2… Threshold current during reverse drive in the clamping mode DA… Drive shaft L1… Length corresponding to the internal space required for the stroke of the hook member Los… Offset amount of the hook L2… Height of the mechanism part in the initial position (retracted state) L3… Length from the drive shaft DA to the front end of the flat surface L4… Horizontal length from the drive shaft DA to the tip of the hook L5… Horizontal length from the tip of the hook to the tip of the protruding leg P… Nail( Pull out Work object) Pc… Virtual central axis when the nail P is assumed to be straight Ph… Nail head Pt… Nail foot Q… Concrete panel( Another Work object) R… Crossbar( Another Work object) U… (Users) User VP… Virtual plane including the drive shaft W0… Target initial position W1… Reverse side limit position W2… Forward side limit position Wop… Origin position X0… Initial position setting specified amount X1… Specified amount X2… Specified amount Xap… Abnormality prevention specified amount

Claims

1. An electric tool used for operations such as nail pulling, comprising: a main body portion; an engaging member provided on the main body portion side and having an engaging portion that engages with a part of the object to be pulled out; a sliding member that moves in and out with respect to the main body portion and moves a part of it closer to and away from the engaging member; a drive source for operating the sliding member; a contact portion provided at an end of the sliding member and in contact with a part of another work object; and the engaging portion of the engaging member is disposed at a position offset from a drive shaft that extends along the sliding direction of the sliding member through the sliding member to the tip side of the engaging portion, the contact portion has a contact surface with a length exceeding the distance between the virtual central axis Pc of the object to be pulled out engaged with the engaging portion and the drive shaft in a direction connecting the virtual central axis Pc and the drive shaft, the engaging member is fixed to the main body portion side, and the engaging member has a structure in which a driving force for moving the sliding member in and out does not act, an electric tool.

2. The electric tool according to claim 1, wherein the engaging portion is formed to protrude in a direction perpendicular to the drive shaft.

3. The electric tool according to claim 2, wherein the engaging member is configured to be able to change the direction in which the engaging portion protrudes.

4. The electric tool according to claim 3, wherein a portion including the engaging portion of the engaging member is provided as a rotatable portion that is rotatable around the drive shaft.

5. The electric tool according to claim 4, further comprising a resistor that imparts a predetermined resistance to the rotational movement of the rotatable portion of the engaging member around the drive shaft.

6. The electric tool according to claim 4 or 5, further comprising a defining means for defining the circumferential position of the rotatable portion of the engaging member as the sliding member slides.

7. The electric tool according to any one of claims 1 to 6, wherein a holding portion is formed on the sliding member that can sandwich a member disposed perpendicular to the drive shaft together with the engaging portion of the engaging member.

8. The electric tool according to claim 7, wherein a portion including the holding portion of the sliding member is provided as a rotatable portion that is rotatable around the drive shaft.

9. The electric tool according to claim 8, further comprising a resistor that imparts a predetermined resistance to the rotational movement of the rotatable portion of the sliding member around the drive shaft.

10. The electric power tool according to claim 8 or 9, further comprising defining means for defining a circumferential position of the rotatable portion of the sliding member as the sliding member slides.

11. In a state where the sliding member is in an initial position retracted into the main body portion, the holding portion is formed at a position where at least a part thereof overlaps the engaging portion of the engaging member in the axial direction of the drive shaft. The electric power tool according to any one of claims 8 to 10.

12. The electric power tool according to any one of claims 2 to 11, further comprising a side cover portion constituting a peripheral portion of the sliding member.

13. In the electric power tool according to claim 12, the side cover portion slides integrally as a part of the sliding member.

14. A holding portion capable of sandwiching a member disposed perpendicular to the drive shaft between the holding portion and the engaging portion of the engaging member is formed on the sliding member, and at least a part of the holding portion and the engaging portion are formed so as to be located outside the cover. The electric power tool according to claim 12 or 13.

15. In the electric power tool according to claim 14, the holding portion of the sliding member is formed to project in a direction perpendicular to the diameter of the drive shaft more than the engaging portion of the engaging member.

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