Agreement tools

Abstract

To provide a fastening tool which can complete an operation for fastening a screw even if normal completion of the operation for fastening the screw cannot be detected.SOLUTION: A fastening tool 1 comprises: a bit rotating motor 40 which rotates a driver bit; and a control part 100 to which an abnormality detection rotation amount for detecting occurrence of abnormality is set on the basis of a rotation amount of the bit rotating motor 40, and which stops rotation of the bit rotating motor 40 when the driver bit has not reached an advance completion position and the rotation amount of the bit rotating motor 40 reaches the abnormality detection rotation amount.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a fastening tool in which a driver bit is engaged with a screw, the screw is pressed against an object to be fastened by the driver bit, and the driver bit is rotated to screw in the screw. [Background technology]

[0002] A portable tool known as a driving machine is known that uses the air pressure of compressed air supplied from an air compressor or the combustion pressure of gas to drive connecting fasteners loaded in a magazine one after another from the tip of a driver guide.

[0003] In the past, a pneumatic screw driver has been proposed as a tool that rotates a bit to tighten a screw and moves the bit in the direction of driving the screw, using an air motor to rotate the bit and air pressure to move it in the direction of driving the screw (see, for example, Patent Document 1).

[0004] Also, a screw driver has been proposed in which a spring is compressed by the driving force of a motor that rotates a driver bit, and the driver bit is moved axially by the bias of the spring to drive the screw (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 5262461 [Patent Document 2] Patent No. 6197547 Summary of the Invention [Problem to be solved by the invention]

[0006] In screw drivers that drive screws by moving a driver bit axially using the force of a spring, the completion of the screw tightening operation is determined by detecting the descent of the driver bit using a sensor that detects the driver bit.However, if the sensor breaks or the screw falls over inside the nose and the driver bit cannot move forward, it will no longer be possible to detect the completion of the screw tightening operation, which could lead to the problem of the screw continuing to be tightened.

[0007] The present invention has been made to solve such problems, and aims to provide a fastening tool that can terminate the screw tightening operation even if it cannot detect the normal completion of the screw tightening operation. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the present invention provides a bit holding unit that detachably holds a driver bit and is rotatable in the circumferential direction of the driver bit and movable in the axial direction, a first motor that rotates the bit holding unit, and a position detection unit that detects the movement position of the bit holding unit along the axial direction of the driver bit. an operation switch unit that can switch between an on state and an off state; and a control unit that rotates the first motor to rotate the bit holding unit, wherein the control unit determines whether the bit holding unit has moved to the forward movement end position based on the movement position of the bit holding unit detected by the position detection unit, and stops the rotation of the first motor when the bit holding unit has not reached the forward movement end position and a stop condition for the first motor is satisfied. At the same time, when the operation switch unit is in the ON state, the first motor is driven, and when the operation switch unit is in the OFF state, the first motor is stopped. However, before the bit holding unit moves to the forward movement end position, the first motor continues to rotate even if the operation switch unit is switched to the OFF state. It is a fastening tool. The present invention also provides a fastening tool comprising: a bit holding portion that detachably holds a driver bit and is rotatable in the circumferential direction of the driver bit and movable in the axial direction; a first motor that rotates the bit holding portion; a second motor that moves the bit holding portion along the axial direction; a position detection portion that detects the movement position of the bit holding portion along the axial direction of the driver bit; and a control portion that rotates the first motor to rotate the bit holding portion and rotates the second motor to move the bit holding portion along the axial direction, wherein the control portion determines whether the bit holding portion has moved to an advance end position based on the movement position of the bit holding portion detected by the position detection portion, and when the bit holding portion has not reached the advance end position and a stop condition for the first motor is satisfied, stops the rotation of the first motor and determines a fastening object to which a screw engaged with the driver bit will be fastened based on the rotation amount or rotation speed of the second motor, and changes the stop condition depending on the fastening object. Furthermore, the present invention is a fastening tool comprising: a bit holding portion that detachably holds a driver bit and is rotatable in the circumferential direction of the driver bit and movable in the axial direction; a first motor that rotates the bit holding portion; a second motor that moves the bit holding portion along the axial direction; a position detection portion that detects the movement position of the bit holding portion along the axial direction of the driver bit; and a control portion that rotates the first motor to rotate the bit holding portion and rotates the second motor to move the bit holding portion along the axial direction, wherein the control portion determines whether the bit holding portion has moved to the forward movement end position based on the movement position of the bit holding portion detected by the position detection portion, and when the bit holding portion has not reached the forward movement end position and the stop condition of the first motor is satisfied, the control portion stops rotation of the first motor and starts the operation of fastening the screw into the object to be fastened, and changes the stop condition depending on the load applied to the first or second motor via the screw.

[0009] In the present invention, when it is determined that the driver bit held in the bit holding unit has moved to the forward movement end position, the rotation of the first motor is stopped. However, when it is not possible to detect that the driver bit held in the bit holding unit has moved to the forward movement end position and it is determined that the driver bit held in the bit holding unit has not moved to the forward movement end position, the rotation of the first motor is stopped when a stop condition is satisfied.

[0010] The present invention also provides a fastening tool comprising: a bit holding portion that detachably holds a driver bit and is rotatable in the circumferential direction of the driver bit and movable in the axial direction; a first motor that rotates the bit holding portion; a contact member that contacts a fastening object to which a screw engaged with the driver bit is fastened; a contact switch portion that is switched between an on state and an off state by axial movement of the contact member; a position detection portion that detects the movement position of the bit holding portion along the axial direction of the driver bit; and a control portion that rotates the first motor to rotate the bit holding portion, wherein the control portion controls the timing to stop driving the first motor based on the operation of the contact switch portion, and when it is determined that the bit holding portion has moved to the forward movement end position based on the movement position of the bit holding portion detected by the position detection portion, it determines whether the contact switch portion is operated or not, and if the contact switch portion is in the off state, the first motor continues to rotate until a stop condition is satisfied.

[0011] In this invention, when it is determined that the driver bit held by the bit holding unit has moved to the forward movement end position, the rotation of the first motor is stopped. However, if the contact switch unit is inactive, it is assumed that the fastening tool is floating above the object to be fastened, so the first motor continues to rotate in one direction to fasten the screw, and when the contact switch unit is subsequently activated, the rotation of the first motor is stopped. On the other hand, if the contact switch unit continues to be inactive, the rotation of the first motor is stopped when a stop condition is met. [Effects of the Invention]

[0012] In the present invention, even in a state where it cannot be detected that the driver bit held in the bit holding portion has moved to the forward movement end position, the rotation of the first motor can be stopped.

[0013] Furthermore, in the present invention, after the driver bit held in the bit holding section has moved to the forward end position, the rotation of the first motor can be stopped even when the timing to stop driving the first motor cannot be detected based on whether or not the contact switch section has been activated. [Brief explanation of the drawings]

[0014] [Figure 1A] FIG. 2 is a side cross-sectional view showing an example of the internal structure of the fastening tool of the present embodiment. [Figure 1B] FIG. 2 is a top cross-sectional view showing an example of the internal structure of the fastening tool of the present embodiment. [Figure 1C] FIG. 2 is an exploded perspective view showing an example of the internal structure of the fastening tool of the present embodiment. [Figure 2A] 1 is a perspective view showing an example of a configuration of a main part of a fastening tool according to an embodiment of the present invention; [Figure 2B] 1 is a perspective view showing an example of a configuration of a main part of a fastening tool according to an embodiment of the present invention; [Figure 3A] 1 is a cross-sectional perspective view showing an example of a configuration of a main part of a fastening tool according to an embodiment of the present invention; [Figure 3B] 1 is a cross-sectional perspective view showing an example of a configuration of a main part of a fastening tool according to an embodiment of the present invention; [Figure 4] FIG. 2 is a perspective view showing an example of a screw feed portion and a nose portion of the present embodiment. [Figure 5] 1 is a block diagram showing an example of a fastening tool according to an embodiment of the present invention; [Figure 6] FIG. 2 is a perspective view illustrating an example of a setting unit. [Figure 7A] 4 is a flowchart showing an example of an operation of the fastening tool according to the present embodiment. [Figure 7B] 4 is a flowchart showing an example of an operation of the fastening tool according to the present embodiment. [Figure 7C] 4 is a flowchart showing an example of an operation of the fastening tool according to the present embodiment. [Figure 8A] 10 is a graph showing the relationship between the rotation speed of a bit rotating motor and a bit moving motor. [Figure 8B]10 is a graph showing the relationship between the rotation speed of a bit rotating motor and a bit moving motor. DETAILED DESCRIPTION OF THE INVENTION

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the fastening tool of the present invention will be described with reference to the drawings.

[0016] <Configuration example of fastening tool according to this embodiment> FIG. 1A is a side cross-sectional view showing an example of the internal structure of the fastening tool of the present embodiment, FIG. 1B is a top cross-sectional view showing an example of the internal structure of the fastening tool of the present embodiment, and FIG. 1C is an exploded oblique view showing an example of the internal structure of the fastening tool of the present embodiment.

[0017] The fastening tool 1 of this embodiment includes a bit holding unit 3 that holds a driver bit 2 rotatably and axially movable, a first drive unit 4 that rotates the driver bit 2 held by the bit holding unit 3, and a second drive unit 5 that moves the driver bit 2 held by the bit holding unit 3 in the axial direction.

[0018] The fastening tool 1 also includes a screw storage section 6 in which the screw 200 is stored, a screw feed section 7 (described later) that feeds the screw stored in the screw storage section 6, and a nose section 8 that is pressed against the object to be fastened and from which the screw 200 is ejected.

[0019] Furthermore, the fastening tool 1 includes a tool body 10 and a handle 11. The fastening tool 1 also includes, at the end of the handle 11, a battery attachment portion 13 to which a battery 12 is detachably attached.

[0020] In the fastening tool 1, the tool body 10 extends in one direction along the axial direction of the driver bit 2 indicated by arrows A1 and A2, and the handle 11 extends in another direction intersecting the extension direction of the tool body 10. In the fastening tool 1, the direction in which the tool body 10 extends, i.e., the axial direction of the driver bit 2 indicated by arrows A1 and A2, is defined as the front-rear direction. In addition, in the fastening tool 1, the direction in which the handle 11 extends is defined as the up-down direction. Furthermore, in the fastening tool 1, the direction perpendicular to the extension direction of the tool body 10 and the extension direction of the handle 11 is defined as the left-right direction.

[0021] The first drive unit 4 is provided on one side of the tool body 10, i.e., the rear side, across the handle 11. The second drive unit 5 is provided on the other side of the tool body 10, i.e., the front side, across the handle 11.

[0022] The screw storage section 6 stores a plurality of screws 200 connected by a connecting band and wound in a spiral shape.

[0023] 2A and 2B are perspective views showing an example of the configuration of the main parts of the fastening tool of this embodiment, and FIGS. 3A and 3B are cross-sectional perspective views showing an example of the configuration of the main parts of the fastening tool of this embodiment. Next, the bit holding unit 3 and the first driving unit 4 will be described with reference to each figure.

[0024] The bit holding portion 3 includes a holding member 30 that detachably holds the driver bit 2, a rotary guide member 31 that supports the holding member 30 so that it can move in the forward and backward directions indicated by arrows A1 and A2 along the axial direction of the driver bit 2 and rotates together with the holding member 30, a moving member 32 that moves the holding member 30 in the forward and backward directions along the rotary guide member 31, and a biasing member 33 that biases the moving member 32 in the backward direction indicated by arrow A2.

[0025] The holding member 30 is configured as, for example, a cylindrical member whose outer diameter is slightly smaller than the inner diameter of the rotation guide member 31 and which can be placed inside the rotation guide member 31. The holding member 30 has an opening 30a at its front end along the axial direction of the driver bit 2, the opening 30a having a shape that matches the cross-sectional shape of the driver bit 2. The holding member 30 is provided with a detachable holding mechanism 30c in the opening 30a that detachably holds the driver bit 2. The opening 30a of the holding member 30 is exposed to the inside of the rotation guide member 31, and the driver bit 2 is detachably inserted into the opening 30a.

[0026] The detachable holding mechanism 30c includes a ball 30d exposed in the opening 30a and a spring 30e that biases the ball 30d in the direction of exposure in the opening 30a. The spring 30e is an annular leaf spring and is fitted around the outer periphery of the holding member 30.

[0027] In the detachable holding mechanism 30c, the ball 30d biased by the spring 30e fits into a groove in the driver bit 2, thereby preventing the driver bit 2 from accidentally coming out of the holding member 30. Furthermore, when a force of a predetermined magnitude or greater is applied in a direction in which the driver bit 2 is removed from the holding member 30, the ball 30d retracts while deforming the annular spring 30e, allowing the driver bit 2 to be removed from the holding member 30.

[0028] The rotation guide member 31 extends in the extension direction of the tool body 10, i.e., in the front-to-rear direction indicated by arrows A1 and A2 along the axial direction of the driver bit 2. The rotation guide member 31 has a cylindrical shape inside which the holding member 30 fits, and its front end is rotatably supported via a bearing 34a, which is an example of a bearing, on a front frame 10b provided on the front side of a case 10a that forms the exterior of the tool body 10. In addition, the rotation guide member 31 has its rear end connected to the first drive unit 4.

[0029] The rotation guide member 31 has grooves 31a formed at two radially opposing locations on its peripheral surface, the grooves 31a extending in the front-to-rear direction indicated by arrows A1 and A2 along the axial direction of the driver bit 2. The rotation guide member 31 penetrates the holding member 30 in the radial direction, and connecting members 30b protruding from both sides of the holding member 30 enter the grooves 31a, thereby connecting the rotation guide member 31 to the holding member 30 via the connecting members 30b.

[0030] The connecting member 30b is composed of a cylindrical member with an oval cross section, and the longitudinal direction of the oval shape is oriented along the extension direction of the groove 31a, which is parallel to the axial direction of the driver bit 2, as indicated by arrows A1 and A2. The lateral direction of the oval shape of the connecting member 30b is oriented perpendicular to the extension direction of the groove 31a, as indicated by arrows B1 and B2, i.e., along the rotation direction of the rotation guide member 31. The width of the oval shape of the connecting member 30b in the lateral direction, i.e., the width along the rotation direction of the rotation guide member 31, is configured to be slightly smaller than the width of the groove 31a along the same direction.

[0031] As a result, the connecting member 30b inserted in the groove 31a is supported in the groove 31a so as to be movable along the axial direction of the rotation guide member 31. Furthermore, the movement of the connecting member 30b in the rotational direction relative to the rotation guide member 31 is restricted between one side surface and the other side surface of the groove 31a that are aligned along the extension direction of the groove 31a. Therefore, as the rotation guide member 31 rotates, the connecting member 30b is pressed against one side surface or the other side surface of the groove 31a depending on the rotational direction of the rotation guide member 31, and receives a force from the rotation guide member 31 in the circumferential direction, which is the rotational direction.

[0032] Therefore, when the rotation guide member 31 rotates, the connecting member 30b is pressed into the groove portion 31a of the rotation guide member 31, causing the holding member 30 to rotate together with the rotation guide member 31. Furthermore, the connecting member 30b is guided by the groove portion 31a of the rotation guide member 31, and the holding member 30 moves in the front-to-rear direction along the axial direction of the driver bit 2.

[0033] The moving member 32 includes a first moving member 32a that rotates together with the holding member 30 and moves the holding member 30 in the forward and backward directions along the rotation guide member 31, a second moving member 32c that is supported by the first moving member 32a via a bearing 32b and pushes the first moving member 32a via the bearing 32b, and a buffer member 32d that is attached to the rear side of the second moving member 32c.

[0034] The first moving member 32a has an inner diameter slightly larger than the outer diameter of the rotation guide member 31 and is configured as, for example, a cylindrical member that is placed on the outside of the rotation guide member 31. The first moving member 32a is connected to the holding member 30 via a connecting member 30b that protrudes from a groove portion 31a of the rotation guide member 31, and is supported so as to be movable along the axial direction of the rotation guide member 31.

[0035] Bearing 32b is an example of a bearing, and is inserted between the outer periphery of first moving member 32a and the inner periphery of second moving member 32c. First moving member 32a constitutes a bearing inner ring holding member that holds the inner ring of bearing 32b, and second moving member 32c constitutes a bearing outer ring holding member that holds the outer ring of bearing 32b. The inner ring of bearing 32b is supported on the outer periphery of first moving member 32a so as to be immovable in both the rotational and axial directions, and the outer ring is supported on the inner periphery of second moving member 32c so as to be immovable in both the rotational and axial directions.

[0036] As a result, the second moving member 32c is connected to the first moving member 32a via the bearing 32b in a state where movement in the front-to-rear direction along the axial direction is restricted. Also, the second moving member 32c rotatably supports the first moving member 32a via the bearing 32b.

[0037] Therefore, as the second moving member 32c moves back and forth along the axial direction, the first moving member 32a is pushed by the second moving member 32c via the bearing 32b, and moves back and forth along the axial direction together with the second moving member 32c. In addition, the first moving member 32a is rotatable relative to the second moving member 32c, which is non-rotatable relative to the rotation guide member 31.

[0038] The biasing member 33, in this example, is formed by a coil spring and is placed outside the rotation guide member 31 between the front frame 10b, which is provided on the front side of the case 10a of the tool body 10, and the second moving member 32c of the moving member 32, and abuts against a spring seat 32f that is arranged so as to contact the end face of the outer ring of the bearing 32b. The biasing member 33 is compressed when the moving member 32 moves forward as indicated by arrow A1, and applies a force to the moving member 32 that pushes the moving member 32 backward as indicated by arrow A2.

[0039] The first drive unit 4 includes a bit rotation motor 40 driven by electricity supplied from the battery 12, and a reducer 41. The bit rotation motor 40 is an example of a first motor, and a shaft 40a of the bit rotation motor 40 is connected to the reducer 41, and a shaft 41a of the reducer 41 is connected to the rotation guide member 31. In the first drive unit 4, the reducer 41 is configured using a planetary gear, and the bit rotation motor 40 is arranged coaxially with the rotation guide member 31, the holding member 30, and the driver bit 2 held by the holding member 30.

[0040] The first drive unit 4 has a bit rotation motor 40 and a reducer 41 attached to a rear frame 10c provided on the rear side of the case 10a of the tool body 10, and a shaft 41a of the reducer 41 is supported by the rear frame 10c via a bearing 42. The rear end of the rotation guide member 31 is connected to the shaft 41a of the reducer 41, and the shaft 41a is supported by the rear frame 10c via the bearing 42, so that the rotation guide member 31 is rotatably supported via the bearing 42, which is an example of a bearing.

[0041] The bit holding unit 3 and the first drive unit 4 are assembled together by connecting the front frame 10b and the rear frame 10c with a connecting member 10d extending in the front-to-rear direction, and the front frame 10b is fixed to the case 10a of the tool body 10 with screws 10e.

[0042] Furthermore, the front end of the rotation guide member 31 of the bit holding part 3 is supported via a bearing 34a on a front frame 10b fixed to the front side of the case 10a of the tool body 10, and the rear end of the rotation guide member 31 is supported via a shaft 41a of the reducer 41 and a bearing 42 on a rear frame 10c fixed to the rear side of the case 10a. Thus, the rotation guide member 31 of the bit holding part 3 is rotatably supported on the tool body 10.

[0043] As a result, the first driving unit 4 rotates the rotary guide member 31 using the bit rotation motor 40. When the rotary guide member 31 rotates, the holding member 30 that holds the driver bit 2 rotates together with the rotary guide member 31 as the connecting member 30b is pressed into the groove portion 31a of the rotary guide member 31.

[0044] The bit holding unit 3 has a guide member 32g provided on the second moving member 32c. The guide member 32g is guided by the connecting member 10d, so that the second moving member 32c can move in the forward and backward directions indicated by arrows A1 and A2 along the axial direction of the driver bit 2, and its rotation following the rotation guide member 31 is restricted.

[0045] Next, the second drive unit 5 will be described with reference to the respective drawings. The second drive unit 5 includes a bit moving motor 50 driven by electricity supplied from the battery 12, and a reducer 51. The bit moving motor 50 is an example of a second motor, and a shaft 50a of the bit moving motor 50 is connected to the reducer 51, and a shaft 51a of the reducer 51 is connected to a pulley 52, which is an example of a transmission member. In the second drive unit 5, the pulley 52 is supported on the tool body 10 via a bearing 53. In the second drive unit 5, the shaft 50a of the bit moving motor 50 is arranged along the extension direction of the handle 11.

[0046] In the second driving unit 5, one end of a linear wire 54, which is an example of a transmission member, is connected to the pulley 52, and the wire 54 is wound around the pulley 52 as the pulley 52 rotates. The other end of the wire 54 is connected to a wire connecting portion 32h provided on the second moving member 32c of the moving member 32.

[0047] As a result, the second drive unit 5 rotates the pulley 52 using the bit moving motor 50 to wind up the wire 54, thereby moving the second moving member 32c forward as indicated by the arrow A1. As the second moving member 32c moves forward, the first moving member 32a is pushed via the bearing 32b, and the first moving member 32a moves forward together with the second moving member 32c along the axial direction of the bit holding unit 3. As the first moving member 32a moves forward, the holding member 30 connected to the first moving member 32a via the connecting member 30b moves forward, and the driver bit 2 held by the holding member 30 moves forward as indicated by the arrow A1.

[0048] The second drive unit 5 is disposed offset to one side from approximately the center in the left-right direction of the fastening tool 1 so that the tangent direction of the portion of the pulley 52 around which the wire 54 is wound is along the extension direction of the rotation guide member 31. In addition, the diameter of the pulley 52 is set so that the wire 54 is not wound around the pulley 52 in an overlapping manner when the pulley 52 winds up the wire 54 to move the driver bit 2 a predetermined distance.

[0049] As a result, the relationship between the amount of rotation of the bit moving motor 50 and the amount of movement of the holding member 30 is one to one throughout the entire movable range of the holding member 30, and by controlling the amount of rotation of the bit moving motor 50, it is possible to control the amount of movement of the holding member 30 along the axial direction of the rotation guide member 31. In other words, by controlling the amount of rotation of the bit moving motor 50, it is possible to control the amount of movement of the driver bit 2 attached to the holding member 30.

[0050] Furthermore, the movement speed of the driver bit 2 can be increased in accordance with the rotation speed of the bit movement motor 50. This reduces the time it takes for the driver bit 2 to press the screw 200 against the object to be fastened.

[0051] Note that the wire 54 is flexible enough to be wound around the pulley 52, and therefore cannot push the second moving member 32c to move the moving member 32 rearward. Therefore, a biasing member 33 is provided that is compressed when the moving member 32 moves forward in the direction indicated by arrow A1, and applies a force to the moving member 32 that pushes the moving member 32 rearward in the direction indicated by arrow A2. This allows the pulley 52 to wind up the wire 54, moving the driver bit 2 forward, and allowing the driver bit 2 to move backward after moving forward.

[0052] 4 is a perspective view showing an example of the screw feed section and nose section of this embodiment, and next, the screw feed section 7 and nose section 8 will be described with reference to each drawing. The screw feed section 7 includes a screw feed motor 70, a pinion gear 71 attached to the shaft of the screw feed motor 70 via a reducer, a rack gear 72 that meshes with the pinion gear 71, and an engagement section 73 that is connected to the rack gear 72 and engages with the connecting screw fed from the screw storage section 6.

[0053] The screw feed unit 7 supports a rack gear 72 so that it can move up and down along the feed direction of the connecting screw. When the screw feed motor 70 rotates forward and backward, the screw feed unit 7 causes an engagement portion 73 that engages with the connecting screw to move back and forth up and down, thereby feeding the connecting screw. Note that the screw feed unit 7 may also be configured to reciprocate the engagement portion 73 using a linear driving unit that combines electromagnetic force, such as a solenoid, with a biasing means.

[0054] The nose portion 8 is provided with an injection passage 80 through which the screw 200 is supplied by the screw feed portion 7 and through which the driver bit 2 passes. The nose portion 8 also has an injection port 81a that communicates with the injection passage 80 and is provided with a contact member 81 that comes into contact with an object to be fastened. The nose portion 8 also has a contact arm 82 that moves in the front-to-rear direction in conjunction with the contact member 81.

[0055] Nose portion 8 supports contact member 81 so that it can move in the front-to-rear direction indicated by arrows A1 and A2, and contact arm 82 moves in the front-to-rear direction in conjunction with contact member 81. In nose portion 8, contact member 81 is urged forward by a urging member (not shown), and contact member 81, which is pressed against an object to be fastened and moves rearward, is then urged forward by the urging member.

[0056] The fastening tool 1 includes a contact switch unit 84 that is activated when pressed by a contact arm 82. The contact switch unit 84 is switched between activated and inactivated when pressed by the contact arm 82 as the contact member 81 is pressed against the object to be fastened and the contact arm 82 moves rearward. In this example, a state in which the contact switch unit 84 is not pressed by the contact arm 82 and is in an inactivated state is referred to as the off state of the contact switch unit 84, and a state in which the contact switch unit 84 is pressed by the contact arm 82 and is activated is referred to as the on state of the contact switch unit 84.

[0057] FIG. 5 is a block diagram showing an example of the fastening tool of this embodiment, and next, the configuration relating to the control and operation of the fastening tool 1 will be described with reference to each drawing.

[0058] The fastening tool 1 includes a trigger 9 that receives an operation, and a trigger switch unit 90 that is actuated by the operation of the trigger 9. The trigger 9 is an example of an operating unit, and as shown in FIG. 1A etc., is provided on the front side of the handle 11 and is configured to be operable by the fingers of the hand that grips the handle 11. The trigger switch unit 90 is an example of an operating switch unit, and is actuated when pressed by the trigger 9.

[0059] The trigger switch unit 90 is switched between activated and inactive when pressed by the trigger 9. In this example, the state in which the trigger 9 is not operated, the trigger 9 does not press the trigger switch unit 90, and the trigger switch unit 90 is in an inactive state is referred to as the off state of the trigger switch unit 90, and the state in which the trigger 9 is operated and pressed by the trigger 9, and the trigger switch unit 90 is activated is referred to as the on state of the trigger switch unit 90.

[0060] The fastening tool 1 is equipped with a control unit 100 that controls the first drive unit 4, the second drive unit 5, and the screw feed unit 7 based on the outputs of a trigger switch unit 90 that is actuated by operating a trigger 9 and a contact switch unit 84 that is actuated by being pressed by a contact member 81. The control unit 100 is composed of a circuit board on which various electronic components are mounted, and is stored in a circuit board storage unit 111 provided on the back side of the screw storage unit 6, between the screw storage unit 6 and the handle 11, as shown in FIG. 1A.

[0061] The control unit 100 controls whether or not to drive the bit moving motor 50 of the second drive unit 5 and the bit rotating motor 40 of the first drive unit 4 based on a combination of whether the contact switch unit 84 is in the on or off state and whether the trigger switch unit 90 is in the on or off state.

[0062] As described above, the fastening tool 1 includes the first drive unit 4 that rotates the driver bit 2 held in the holding member 30 by the bit holding unit 3 by driving the bit rotation motor 40. The fastening tool 1 also includes the second drive unit 5 that moves the driver bit 2 held in the holding member 30 by the bit holding unit 3 in the forward and backward directions along the axial direction by driving the bit movement motor 50.

[0063] In the fastening tool 1, when the bit movement motor 50 rotates in a predetermined direction, the driver bit 2 held by the holding member 30 in the bit holding section 3 moves (advances) in the forward direction indicated by the arrow A1. In addition, when the bit rotation motor 40 rotates in a predetermined direction, the fastening tool 1 rotates the driver bit 2 in the direction for fastening the screw 200.

[0064] The fastening tool 1 advances the driver bit 2 by rotating the bit movement motor 50, thereby engaging the driver bit 2 with the recess 200a of the screw 200, moving the screw 200 forward and pressing it against the object to be fastened.

[0065] Furthermore, the fastening tool 1 rotates the driver bit 2 in a direction for fastening the screw 200 by rotation of the bit rotation motor 40, thereby fastening the screw 200 engaged with the driver bit 2 into the object to be fastened.

[0066] Furthermore, the fastening tool 1 rotates the bit movement motor 50 in conjunction with the rotation of the bit rotation motor 40, thereby moving the driver bit 2 forward in accordance with the fastening of the screw 200.

[0067] Therefore, the control unit 100 controls the amount of movement (advancement) of the driver bit 2 by controlling the amount of rotation of the bit moving motor 50. The control unit 100 controls the amount of movement of the driver bit 2, thereby controlling the stop position of the driver bit 2 along the axial direction.

[0068] Furthermore, the control unit 100 controls the rotation speed of the bit rotation motor 40 and the rotation speed of the bit movement motor 50 to move the driver bit 2 forward in accordance with the fastening of the screw 200 .

[0069] The fastening tool 1 includes a position detection unit 113 that detects the movement position of the bit holding unit 3 along the axial direction of the driver bit 2 so that the control unit 100 can control the movement amount (advancement amount) of the driver bit 2. The position detection unit 113 detects the rotation amount of the bit movement motor 50, and detects the movement position of the bit holding unit 3 based on the rotation amount of the bit movement motor 50. The control unit 100 determines whether the bit holding unit 3 has moved to a predetermined advance end position based on the movement position of the bit holding unit 3 detected by the position detection unit 113. The function of the position detection unit may be realized by the control unit 100.

[0070] The control unit 100 sets a first condition for determining whether the driver bit 2 held in the bit holding unit 3 has moved axially to the advance end position, and also sets a second condition as a stop condition for determining whether to stop the rotation of the bit rotation motor 40 and the bit movement motor 50. When the control unit 100 determines that the driver bit 2 held in the bit holding unit 3 has not been detected to have moved to the advance end position based on the first condition, it stops the rotation of the bit rotation motor 40 and the bit movement motor 50 based on the second condition.

[0071] As a first condition, the control unit 100 controls the position along the axial direction of the driver bit 2 held by the bit holding unit 3 based on the amount of rotation of the bit moving motor 50. For this reason, the control unit 100 sets a specified amount of rotation of the bit moving motor 50 from when the bit moving motor 50 starts to rotate until the driver bit 2 held by the bit holding unit 3 moves along the axial direction to a predetermined forward movement end position.

[0072] In addition, when an abnormality occurs such that the position of the driver bit 2 along the axial direction cannot be controlled based on the rotation amount of the bit moving motor 50, the control unit 100 sets an abnormality detection rotation amount of the bit rotating motor 40 that detects the occurrence of an abnormality based on the rotation amount of the bit rotating motor 40 as a second condition for determining whether to stop the rotation of the bit moving motor 50 and the bit rotating motor 40.

[0073] If, after starting the rotation of the bit rotation motor 40 and the bit movement motor 50, the rotation amount of the bit movement motor 50 fails to reach the specified rotation amount and reaches the abnormality detection rotation amount, the control unit 100 determines that the stop conditions for the bit rotation motor 40 and the bit movement motor 50 have been met and stops the rotation of the bit rotation motor 40 and the bit movement motor 50.

[0074] Furthermore, when an abnormality occurs such that the axial position of the driver bit 2 cannot be controlled based on the amount of rotation of the bit moving motor 50, the control unit 100 sets a specified abnormality detection time that detects the occurrence of an abnormality based on the elapsed time from the start of the operation to fasten the screw 200 as a second condition for determining whether to stop the rotation of the bit moving motor 50 and the bit rotating motor 40. As the elapsed time from the start of the operation to fasten the screw 200, for example, a specified abnormality detection time that detects the occurrence of an abnormality based on the elapsed time from the start of rotation of the bit moving motor 50 is set.

[0075] The control unit 100 stops the rotation of the bit rotation motor 40 and the bit movement motor 50 when the amount of rotation of the bit movement motor 50 does not reach the specified amount of rotation and the time since the rotation of the bit movement motor 50 started reaches the specified abnormality detection time.

[0076] If the trigger switch unit 90 is turned off by operating the trigger 9 before the control unit 100 determines that the driver bit 2 held in the bit holding unit 3 has moved to the forward end position based on the amount of rotation of the bit moving motor 50, the control unit 100 continues to rotate the bit rotation motor 40 and the bit moving motor 50.

[0077] Furthermore, the control unit 100 identifies the object to be fastened, and if the object to be fastened is made of a material that may not allow the screw 200 to be fastened, it stops the rotation of the bit rotation motor 40 and the bit movement motor 50 based on a second condition. Furthermore, if the object to be fastened is made of a material that may not allow the screw 200 to be fastened, when the trigger switch unit 90 is turned off by operating the trigger 9, it stops the rotation of the bit rotation motor 40 and the bit movement motor 50.

[0078] The fastening tool 1 includes a setting unit 110 that sets the amount of rotation of the bit moving motor 50, which determines the amount of advancement of the driver bit 2. Fig. 6 is a perspective view showing an example of the setting unit, and next, the setting unit 110 will be described with reference to each drawing.

[0079] The setting unit 110 is an example of a setting means, and is configured to allow any setting value to be selected from a plurality of setting values, or to allow any setting value to be selected in a stepless manner.

[0080] In this example, the setting unit 110 is configured such that a setting value is selected using an operation unit 110a that is made up of buttons. Alternatively, the operation unit 110a may be configured such that a setting value is selected using a rotary dial. Alternatively, the setting unit 110 may be configured to display the selected setting value by, for example, indicating the current value with a label or engraving, or by indicating the current value on a display unit 110b such as an LED, so that the operator can easily grasp the current setting value. The information displayed on the display unit 110b includes the setting value of the screw depth that is determined by the advancement amount of the driver bit 2, the power ON / OFF status, the selected operation mode from various selectable operation modes, the presence or absence of a screw, the remaining amount of screws, the presence or absence of an abnormality, etc.

[0081] The setting sections 110 are provided on both the left and right sides of the surface facing the handle 11 in the board storage section 111 provided on the rear side of the screw storage section 6.

[0082] This makes it possible to visually recognize the setting portion 110 from both the left and right sides of the handle 11 when the fastening tool 1 is viewed from the rear.

[0083] <Example of operation of the fastening tool according to this embodiment> Figures 7A, 7B, and 7C are flowcharts showing an example of the operation of the fastening tool of this embodiment, and Figures 8A and 8B are graphs showing the relationship between the rotational speeds of the bit rotating motor and the bit moving motor. Next, the fastening operation of the fastening tool of this embodiment will be explained with reference to each figure.

[0084] Fig. 7A shows control for determining whether the rotation amount of the bit rotation motor 40 has reached the abnormality detection rotation amount, and then stopping the rotation of the bit moving motor 50 and the bit rotation motor 40. Fig. 7B shows control for determining whether the time since the start of rotation of the bit moving motor 50 has reached the specified abnormality detection time, and then stopping the rotation of the bit moving motor 50 and the bit rotation motor 40. Fig. 7C shows control for determining the material of the object to be fastened, detecting that the trigger switch unit 90 is off, and then stopping the rotation of the bit moving motor 50 and the bit rotation motor 40.

[0085] In the fastening tool 1, in the standby state, the tip of the driver bit 2 is located at a standby position P1 behind the injection passage 80 as shown in FIG. 1A, and the screw 200 can be supplied to the injection passage 80.

[0086] In the fastening tool 1, the contact member 81 is pressed against the object to be fastened, and the contact arm 82 presses the contact switch unit 84, turning on the contact switch unit 84. In addition, in the fastening tool 1, the trigger 9 is operated, turning on the trigger switch unit 90.

[0087] First, the control in Figure 7A will be explained. When the contact switch unit 84 is turned on in step SA1 in Figure 7A and the trigger switch unit 90 is turned on in step SA2, the control unit 100 drives the bit rotation motor 40 of the first drive unit 4 in step SA3 and drives the bit movement motor 50 of the second drive unit 5 in step SA4.

[0088] When the bit moving motor 50 is driven to rotate in one direction, which is the forward direction, the pulley 52 rotates in the forward direction, causing the wire 54 to be wound around the pulley 52. ​​As the wire 54 is wound around the pulley 52, the second moving member 32c connected to the wire 54 is guided by the rotation guide member 31 and moves forward in the axial direction. When the second moving member 32c moves forward, the first moving member 32a is pushed by the second moving member 32c via the bearing 32b, and moves forward in the axial direction together with the second moving member 32c while compressing the biasing member 33.

[0089] When the first moving member 32a moves forward, the holding member 30 connected to the first moving member 32a by the connecting member 30b moves forward along the axial direction of the driver bit 2, with the connecting member 30b being guided by the groove portion 31a of the rotating guide member 31.

[0090] As a result, the driver bit 2 held by the holding member 30 moves forward as indicated by the arrow A1, engages with the screw 200 supplied to the injection port 81a of the nose portion 8, and moves the screw 200 forward, pressing it against the object to be fastened.

[0091] Furthermore, when the bit rotation motor 40 is driven to rotate in one direction, that is, the forward direction, the rotation guide member 31 rotates in the forward direction. When the rotation guide member 31 rotates in the forward direction, the connecting member 30b connected to the holding member 30 is pressed against the groove portion 31a of the rotation guide member 31, causing the holding member 30 to rotate together with the rotation guide member 31.

[0092] As a result, the driver bit 2 held by the holding member 30 rotates the screw 200 in the forward direction (clockwise) and tightens it into the object to be fastened. The control unit 100, in conjunction with the operation of rotating the driver bit 2 with the first drive unit 4 to tighten the screw into the object to be fastened, moves the driver bit 2 forward with the second drive unit 5 based on the load on the bit rotation motor 40, the rotation speed of the bit rotation motor 40, the load on the bit movement motor 50, the rotation speed of the bit movement motor 50, etc., so that the driver bit 2 follows the screw 200 being tightened into the object to be fastened.

[0093] Fig. 8A shows the relationship between the rotation speeds of the bit rotation motor 40 and the bit movement motor 50 when a screw 200 is normally fastened into a normal object to be fastened, such as wood or plaster. In contrast, Fig. 8B shows the relationship between the rotation speeds of the bit rotation motor 40 and the bit movement motor 50 when the object to be fastened is a steel plate with plaster or the like layered on top, and the screw 200 cannot be normally fastened.

[0094] The control unit 100 determines in step SA5 whether the rotation amount of the bit moving motor 50 has reached the set value selected by the setting unit 110 or the like and the tip of the driver bit 2 has reached the set forward end position.

[0095] If the control unit 100 determines in step SA5 that the rotation amount of the bit moving motor 50 has not reached the predetermined set value, it detects the load applied to the driver bit 2 via the screw 200 in step SA6.

[0096] When the fastening tool 1 starts rotating the driver bit 2 to fasten the screw 200 into the object to be fastened, a load is generated on the driver bit 2 via the screw 200. When a load is generated on the driver bit 2, both the rotation speed V1 of the bit rotation motor 40 and the rotation speed V2 of the bit movement motor 50 decrease. For this reason, the load generated by screw fastening can be detected based on the amount of decrease in the rotation speed V2 of the bit movement motor 50, etc.

[0097] The fastening tool 1 may be used to fasten the screw 200 into fastening objects made of various materials, but the load applied to the driver bit 2 via the screw 200 differs when the screw 200 is fastened into a normal fastening object such as wood or plaster, and when the screw 200 is fastened into a fastening object with plaster or the like layered on a steel plate base.

[0098] When the object to be fastened is a steel plate or the like, when the tip of the screw 200 reaches the steel plate, the load when pressing the screw 200 against the steel plate is larger than when pressing it against wood, plaster, etc., and the load when moving (advancing) the driver bit 2 in the axial direction is also larger.

[0099] However, with the fastening tool 1, even if the object to be fastened is a steel plate or the like, as long as the increase in load when the screw 200 reaches the steel plate and moves (advances) the driver bit 2 axially is within a specified range, the screw 200 can be tightened into the object to be fastened by continuing to rotate the bit rotation motor 40 and the bit movement motor 50.

[0100] Therefore, after timing T1 at which the load due to screw tightening is generated as shown in Figures 8A and 8B, if the control unit 100 determines that the load generated by screw tightening is within a normal range that allows the screw 200 to be tightened into the object to be tightened, it continues to control the position of the driver bit 2 along the axial direction based on the amount of rotation of the bit moving motor 50.

[0101] When the control unit 100 determines in step SA5 described above that the rotation amount of the bit moving motor 50 has reached a predetermined set value (prescribed rotation amount), at timing T2 when the driver bit 2 shown in FIG. 8A has moved the prescribed amount, it stops driving the bit rotation motor 40 in step SA7 of FIG. 7A, stops the rotation of the bit moving motor 50 in the forward direction in step SA8, and then reverses the rotation of the bit moving motor 50 in step SA9.

[0102] When the bit moving motor 50 rotates in the other direction, that is, the reverse direction, the pulley 52 rotates in the reverse direction, causing the wire 54 to be pulled out from the pulley 52. ​​When the wire 54 is pulled out from the pulley 52, the second moving member 32c moves forward, causing the compressed biasing member 33 to expand and push the second moving member 32c rearward.

[0103] The second moving member 32c is pushed rearward by the biasing member 33, and moves rearward along the axial direction while being guided by the rotation guide member 31. When the second moving member 32c moves rearward, the first moving member 32a is pulled by the second moving member 32c via the bearing 32b, and moves rearward along the axial direction together with the second moving member 32c.

[0104] When the first moving member 32a moves rearward, the holding member 30 connected to the first moving member 32a by the connecting member 30b moves rearward along the axial direction of the driver bit 2, with the connecting member 30b being guided by the groove portion 31a of the rotating guide member 31.

[0105] In step SA10, the control unit 100 reverses the rotation of the bit moving motor 50 to the initial position where a predetermined amount of wire 54 is pulled out from the pulley 52, and when the holding member 30 and the moving member 32 move backward to a position where the tip of the driver bit 2 returns to the standby position P1, the control unit 100 stops the reverse rotation of the bit moving motor 50 in step SA11.

[0106] When the trigger switch unit 90 is turned off, the control unit 100 rotates the screw feed motor 70 in one direction to lower the engaging unit 73. When the engaging unit 73 has lowered to a position where it can engage with the next screw 200, the control unit 100 reverses the rotation of the screw feed motor 70 to raise the engaging unit 73 and supply the next screw 200 to the injection passage 80.

[0107] On the other hand, when the object to be fastened is a steel plate or the like, if the screw 200 cannot be pressed against the steel plate to drill a hole, the driver bit 2 cannot move (advance) in the axial direction. Also, if the screw 200 pushed forward by the driver bit 2 becomes stuck in the injection passage 80 or the injection port 81a, the driver bit 2 cannot move (advance) in the axial direction. When the driver bit 2 cannot move (advance) in the axial direction, the amount of rotation of the bit movement motor 50 does not reach the specified amount of rotation.

[0108] In this way, if the load when moving (advancing) the driver bit 2 in the axial direction becomes large due to factors such as the screw 200 being unable to drill a hole in the object to be fastened, or the screw 200 becoming stuck in the injection passage 80 or the injection port 81a, an abnormality may occur in which the screw 200 cannot be tightened into the object to be fastened.

[0109] When such an abnormality occurs, there is a possibility that the rotation amount of the bit moving motor 50 will not reach a predetermined set value. In a control that controls the axial position of the driver bit 2 based on the rotation amount of the bit moving motor 50 and stops the rotation of the bit moving motor 50, the rotation of the bit moving motor 50 cannot be stopped unless the rotation amount of the bit moving motor 50 reaches a predetermined set value.

[0110] Therefore, if the control unit 100 determines in the above-mentioned step SA6 that the increase in load when moving (advancing) the driver bit 2 axially is greater than or equal to a predetermined range before the rotation amount of the bit moving motor 50 reaches a predetermined set value, it determines whether or not to stop the rotation of the bit moving motor 50 and the bit rotating motor 40.

[0111] As a second condition for determining whether to stop the rotation of the bit moving motor 50 and the bit rotating motor 40, the control unit 100 determines in step SA12 whether the rotation amount of the bit rotating motor 40 has reached the abnormality detection rotation amount.

[0112] If an abnormality occurs that prevents the screw 200 from being fastened into the object to be fastened, the driver bit 2 will be in a state of freewheeling relative to the screw 200, and so, as shown in Figure 8B, the rotation speed of the bit rotation motor 40 after timing T2 when the abnormality occurs will not decrease compared to when the tip of the screw 200 drills a hole in the object to be fastened and is then fastened into the object to be fastened. For this reason, it is possible to determine whether or not an abnormality has occurred that prevents the screw 200 from being fastened into the object to be fastened, based on the rotation speed of the bit rotation motor 40.

[0113] When the control unit 100 determines that the rotation amount of the bit rotation motor 40 has reached the abnormality detection rotation amount, at timing T3 when the rotation amount of the bit rotation motor 40 has reached the abnormality detection rotation amount shown in Figure 8B, it stops the rotation of the bit rotation motor 40 in step SA7 described above and stops the rotation of the bit moving motor 50 in step SA8.

[0114] As a result, in the fastening tool 1, which controls the position of the driver bit 2 along the axial direction by the amount of rotation of the bit moving motor 50, if the amount of rotation of the bit moving motor 50 does not reach the specified amount of rotation due to factors such as an abnormality that prevents the screw 200 from being tightened into the object to be fastened, and it is not possible to detect that the driver bit 2 has reached the end of forward movement position, the rotation of the bit rotation motor 40 and the bit moving motor 50 can be stopped based on the amount of rotation of the bit rotation motor 40.

[0115] Next, the control of Figure 7B will be explained. When the contact switch unit 84 is turned on in step SB1 of Figure 7B and the trigger switch unit 90 is turned on in step SB2, the control unit 100 drives the bit rotation motor 40 of the first drive unit 4 in step SB3 and drives the bit movement motor 50 of the second drive unit 5 in step SB4.

[0116] When the bit moving motor 50 is driven to rotate in one direction, that is, the forward direction, the driver bit 2 held by the holding member 30 of the bit holding portion 3 moves forward as indicated by the arrow A1, engages with the screw 200 supplied to the injection port 81a of the nose portion 8, moves the screw 200 forward, and presses it against the object to be fastened.

[0117] Furthermore, when the bit rotation motor 40 is driven to rotate in one direction, that is, the forward direction, the driver bit 2 held by the holding member 30 of the bit holding unit 3 rotates the screw 200 in the forward direction (clockwise) and drives it into the object to be fastened. The control unit 100, in conjunction with the operation of the first drive unit 4 to rotate the driver bit 2 and drive the screw into the object to be fastened, moves the driver bit 2 forward with the second drive unit 5 based on the load on the bit rotation motor 40, the rotation speed of the bit rotation motor 40, the load on the bit movement motor 50, the rotation speed of the bit movement motor 50, etc., thereby causing the driver bit 2 to follow the screw 200 being driven into the object to be fastened.

[0118] In step SB5, the control unit 100 determines whether the rotation amount of the bit moving motor 50 has reached the set value (specified rotation amount) selected by the setting unit 110 or the like, and whether the tip of the driver bit 2 has reached the set forward end position.

[0119] If the control unit 100 determines in step SB5 that the rotation amount of the bit moving motor 50 has not reached the predetermined set value, it detects the load applied to the driver bit 2 via the screw 200 in step SB6.

[0120] After timing T1 at which the load due to screw tightening is generated as shown in Figures 8A and 8B, if the control unit 100 determines that the load generated by screw tightening is within a normal range that allows the screw 200 to be tightened into the object to be tightened, it continues to control the position of the driver bit 2 along the axial direction based on the amount of rotation of the bit moving motor 50.

[0121] When the control unit 100 determines in step SB5 described above that the rotation amount of the bit moving motor 50 has reached a predetermined set value (prescribed rotation amount), at timing T2 when the driver bit 2 shown in FIG. 8A has moved the prescribed amount, it stops driving the bit rotation motor 40 in step SB7 of FIG. 7B, stops the rotation of the bit moving motor 50 in the forward direction in step SB8, and then reverses the rotation of the bit moving motor 50 in step SB9.

[0122] In step SB10, the control unit 100 reverses the bit moving motor 50 to the initial position where a predetermined amount of wire 54 is pulled out from the pulley 52, and when the holding member 30 and the moving member 32 move backward to a position where the tip of the driver bit 2 returns to the standby position P1, the control unit 100 stops the reverse rotation of the bit moving motor 50 in step SB11.

[0123] In response to this, if the control unit 100 determines in step SB6 described above that the increase in load when moving (advancing) the driver bit 2 axially is greater than or equal to a predetermined range before the amount of rotation of the bit moving motor 50 reaches a predetermined set value, it determines whether or not to stop the rotation of the bit moving motor 50 and the bit rotating motor 40.

[0124] As a second condition for determining whether to stop the rotation of the bit moving motor 50 and the bit rotating motor 40, the control unit 100 determines in step SB12 whether a specified time has elapsed since the rotation of the bit moving motor 50 began.

[0125] The time from when the bit moving motor 50 starts to rotate until the amount of rotation of the bit moving motor 50 reaches a set value (prescribed amount of rotation) and the tip of the driver bit 2 reaches a predetermined advance end position is determined by the rotation speed of the bit moving motor 50. However, if an abnormality occurs that prevents the screw 200 from being fastened into the object to be fastened, the driver bit 2 cannot move (advance) in the axial direction, or the movement speed becomes slower than normal, and the amount of rotation of the bit moving motor 50 does not reach the prescribed amount of rotation within the predetermined time. For this reason, it is possible to determine whether or not an abnormality has occurred that prevents the screw 200 from being fastened into the object to be fastened, based on the elapsed time since the bit moving motor 50 started to rotate.

[0126] When the control unit 100 determines that the time since the start of rotation of the bit moving motor 50 has reached the specified abnormality detection time, at timing T3 when the time since the start of rotation of the bit moving motor 50 has reached the specified abnormality detection time as shown in Figure 8B, it stops the rotation of the bit rotating motor 40 in step SB7 described above, and stops the rotation of the bit moving motor 50 in step SB8.

[0127] As a result, in a fastening tool 1 that controls the position of the driver bit 2 along the axial direction by the rotation amount of the bit moving motor 50, if the rotation amount of the bit moving motor 50 does not reach the specified rotation amount due to factors such as an abnormality that prevents the screw 200 from being tightened into the object to be fastened, and it cannot be detected that the driver bit 2 has reached the end of forward movement position, the rotation of the bit rotation motor 40 and the bit moving motor 50 can be stopped based on the elapsed time since the bit moving motor 50 started to rotate.

[0128] Next, the control of Figure 7C will be explained. When the contact switch unit 84 is turned on in step SC1 of Figure 7C and the trigger switch unit 90 is turned on in step SC2, the control unit 100 drives the bit rotation motor 40 of the first drive unit 4 in step SC3 and drives the bit movement motor 50 of the second drive unit 5 in step SC4.

[0129] When the bit moving motor 50 is driven to rotate in one direction, that is, the forward direction, the driver bit 2 held by the holding member 30 of the bit holding portion 3 moves forward as indicated by the arrow A1, engages with the screw 200 supplied to the injection port 81a of the nose portion 8, moves the screw 200 forward, and presses it against the object to be fastened.

[0130] Furthermore, when the bit rotation motor 40 is driven to rotate in one direction, that is, the forward direction, the driver bit 2 held by the holding member 30 of the bit holding unit 3 rotates the screw 200 in the forward direction (clockwise) and drives it into the object to be fastened. The control unit 100, in conjunction with the operation of the first drive unit 4 to rotate the driver bit 2 and drive the screw into the object to be fastened, moves the driver bit 2 forward with the second drive unit 5 based on the load on the bit rotation motor 40, the rotation speed of the bit rotation motor 40, the load on the bit movement motor 50, the rotation speed of the bit movement motor 50, etc., thereby causing the driver bit 2 to follow the screw 200 being driven into the object to be fastened.

[0131] In step SC5, the control unit 100 determines whether the rotation amount of the bit moving motor 50 has reached the set value (specified rotation amount) selected by the setting unit 110 or the like, and whether the tip of the driver bit 2 has reached the set forward end position.

[0132] If the control unit 100 determines in step SC5 that the rotation amount of the bit moving motor 50 has not reached the predetermined set value, it detects the load applied to the driver bit 2 via the screw 200 in step SC6.

[0133] After timing T1 at which the load due to screw tightening is generated as shown in Figures 8A and 8B, if the control unit 100 determines that the load generated by screw tightening is within a normal range that allows the screw 200 to be tightened into the object to be tightened, it continues to control the position of the driver bit 2 along the axial direction based on the amount of rotation of the bit moving motor 50.

[0134] When the control unit 100 determines in step SC5 described above that the rotation amount of the bit moving motor 50 has reached a predetermined set value (prescribed rotation amount), at timing T2 when the driver bit 2 shown in FIG. 8A has moved the prescribed amount, it stops driving the bit rotation motor 40 in step SC7 of FIG. 7C, stops the rotation of the bit moving motor 50 in the forward direction in step SC8, and then reverses the rotation of the bit moving motor 50 in step SC9.

[0135] In step SC10, the control unit 100 reverses the bit moving motor 50 to the initial position where a predetermined amount of wire 54 is pulled out from the pulley 52, and when the holding member 30 and the moving member 32 move backward to a position where the tip of the driver bit 2 returns to the standby position P1, the control unit 100 stops the reverse rotation of the bit moving motor 50 in step SC11.

[0136] In contrast, if the control unit 100 determines in step SC6 described above that the increase in load when moving (advancing) the driver bit 2 axially is greater than or equal to a predetermined range before the rotation amount of the bit moving motor 50 reaches a predetermined set value, it determines whether to stop the rotation of the bit moving motor 50 and the bit rotating motor 40.

[0137] In step SC12, control unit 100 determines the material of the object to be fastened as a second condition for determining whether to stop the rotation of bit moving motor 50 and bit rotating motor 40. If the object to be fastened is a steel plate, the load when drilling a hole in the object to fasten screw 200 is higher than that when the object is made of wood, plaster, or the like.

[0138] Furthermore, if the tip of the screw 200 pressed against the steel plate is crushed, or if the screw 200 cannot be pressed against the steel plate to drill a hole, the driver bit 2 cannot move (advance) in the axial direction. If the driver bit 2 cannot move (advance) in the axial direction, the amount of rotation of the bit movement motor 50 does not reach the specified amount of rotation.

[0139] In this way, if the screw 200 cannot drill a hole in the object to be fastened, and the load when moving (advancing) the driver bit 2 in the axial direction becomes large, there is a possibility that an abnormality has occurred in which the screw 200 cannot be tightened into the object to be fastened.

[0140] When such an abnormality occurs, there is a possibility that the rotation amount of the bit moving motor 50 will not reach a predetermined set value. In a control that controls the axial position of the driver bit 2 based on the rotation amount of the bit moving motor 50 and stops the rotation of the bit moving motor 50, the rotation of the bit moving motor 50 cannot be stopped unless the rotation amount of the bit moving motor 50 reaches a predetermined set value.

[0141] Therefore, if the object to be fastened is made of a material that may not allow the screw 200 to be fastened, the rotation of the bit rotation motor 40 and the bit movement motor 50 can be stopped by operating the trigger 9. For this reason, if the control unit 100 determines in step SC6 above that the increase in load when moving (advancing) the driver bit 2 in the axial direction is greater than or equal to a predetermined range before the amount of rotation of the bit movement motor 50 reaches a predetermined set value, it determines the material of the object to be fastened.

[0142] The control unit 100 may determine the material of the object to be fastened based on the rotation amount of the bit rotation motor 40. When the control unit 100 determines that the rotation amount of the bit rotation motor 40 has reached the abnormality detection rotation amount, the control unit 100 determines that the object to be fastened is a predetermined high-load material, such as a steel plate. The control unit 100 may also determine the material of the object to be fastened based on the time since the bit moving motor 50 started to rotate. When the control unit 100 determines that the time since the bit moving motor 50 started to rotate has reached the abnormality detection specified time, the control unit 100 determines that the object to be fastened is a predetermined high-load material, such as a steel plate. The control unit 100 may also determine the material of the object to be fastened based on the rotation amount of the bit moving motor 50. When the control unit 100 determines that the time since the bit moving motor 50 started to rotate has reached the abnormality detection specified time, the control unit 100 determines that the object to be fastened is a predetermined high-load material, such as a steel plate. In addition, the control unit 100 may determine the material of the object to be fastened based on the rotation speed of the bit moving motor 50. When it determines that the time since the bit moving motor 50 started to rotate has reached a predetermined abnormality detection time, and determines that the rotation amount of the bit moving motor 50 has not reached a predetermined predetermined rotation speed, it determines that the material of the object to be fastened is a predetermined high-load material such as a steel plate.

[0143] If the control unit 100 determines that the material of the object to be fastened is a normal load material, it continues the normal fastening operation. If the control unit 100 determines in step SC5 above that the rotation amount of the bit moving motor 50 has reached a predetermined set value (specified rotation amount), it stops the bit rotation motor 40 and reverses the bit moving motor 50 to return the driver bit 2 to the standby position in order to end the fastening operation.

[0144] When the control unit 100 determines that the material of the object to be fastened is a high-load material, it determines in step SC13 whether the trigger 9 has been operated to turn off the trigger switch unit 90. When the control unit 100 determines that the trigger switch unit 90 has turned off, it stops the rotation of the bit rotation motor 40 in step SC7 described above and stops the rotation of the bit movement motor 50 in step SC8 at timing T3 when the trigger switch unit 90 turns off as shown in FIG. 8B. When the control unit 100 determines that the material of the object to be fastened is a high-load material, it may increase the specified abnormality detection time as a second condition compared to when the material of the object to be fastened is a normal load material. Thus, when the control unit 100 determines that the material of the object to be fastened is a high-load material, if it determines that the trigger switch unit 90 has turned off during the specified abnormality detection time that is increased compared to when the material of the object to be fastened is a normal load material, it stops the rotation of the bit rotation motor 40 and the bit movement motor 50.

[0145] As a result, in a fastening tool 1 in which the position of the driver bit 2 along the axial direction is controlled by the amount of rotation of the bit moving motor 50, if the amount of rotation of the bit moving motor 50 does not reach the specified amount of rotation due to factors such as the object to be fastened being made of a material that may not allow the screw 200 to be tightened, and it is not possible to detect that the driver bit 2 has reached the end of forward movement position, the trigger switch unit 90 can be detected to be off, and the rotation of the bit rotation motor 40 and the bit moving motor 50 can be stopped.

[0146] <Modifications of the fastening tool of this embodiment> The fastening tool 1 may detect, as a first condition, whether or not the fastening tool 1 is lifted up from the object to be fastened from the output of the contact switch unit 84, and control the bit rotating motor 40 and the bit moving motor 50.

[0147] As described above, when the contact switch unit 84 is turned on and the trigger switch unit 90 is turned on, the control unit 100 rotates the bit rotation motor 40 in the forward direction and also rotates the bit movement motor 50 in the forward direction.

[0148] When the control unit 100 determines that the amount of rotation of the bit moving motor 50 rotated in the forward direction has reached a predetermined set value (prescribed amount of rotation), it stops the forward rotation of the bit moving motor 50. In contrast, when the contact switch unit 84 changes from on to off, it determines that the fastening tool 1 is floating in a direction away from the object to be fastened, and continues driving the bit rotating motor 40 in the forward direction while stopping the driving of the bit moving motor 50.

[0149] As a result, the driver bit 2 rotates the screw 200 in the forward direction, further tightening it into the object to be fastened, and the fastening tool 1 moves in a direction approaching the object to be fastened. Therefore, the fastening tool 1 moves relative to the contact arm 82, and the contact arm 82 presses the contact switch unit 84, turning the contact switch unit 84 on. When the contact switch unit 84 turns on, the control unit 100 stops the bit rotation motor 40 and reverses the bit movement motor 50 to return the driver bit 2 to its standby position, in order to end the fastening operation.

[0150] However, if an abnormality occurs that prevents the screw 200 from being tightened into the object to be fastened, the driver bit 2 will spin freely relative to the screw 200, and the screw 200 will not be tightened further into the object to be fastened, so the contact switch unit 84 will not turn on.

[0151] Therefore, as a second condition, the control unit 100 stops the rotation of the bit rotating motor 40 when it determines that the rotation amount of the bit rotating motor 40 has reached the abnormality detection rotation amount.

[0152] As a result, in the fastening tool 1, which determines based on the output of the contact switch unit 84 that the fastening tool 1 is floating away from the object to be fastened and continues to drive the bit rotation motor 40 to rotate in the forward direction, the rotation of the bit rotation motor 40 can be stopped based on the amount of rotation of the bit rotation motor 40 even if the contact switch unit 84 does not turn on again.

[0153] Furthermore, as a second condition, when the control unit 100 determines that the time since the start of the operation of fastening the screw 200 has reached the specified abnormality detection time, it stops the rotation of the bit rotation motor 40.

[0154] As a result, in the fastening tool 1, which determines based on the output of the contact switch unit 84 that the fastening tool 1 is floating in a direction away from the object to be fastened and continues to drive the bit rotation motor 40 to rotate in the forward direction, the rotation of the bit rotation motor 40 can be stopped based on the time since the start of the tightening operation of the screw 200, even if the contact switch unit 84 does not turn on again. [Explanation of symbols]

[0155] REFERENCE SIGNS LIST 1 fastening tool, 10 tool body, 11 handle, 2 driver bit, 3 bit holding portion, 30 holding member, 31 rotation guide member, 32 moving member, 33 biasing member, 4 first drive portion, 40 bit rotation motor (first motor), 5 second drive portion, 50 bit movement motor (second motor), 52 pulley, 54 wire, 6 screw storage portion, 7 screw feed portion, 8 nose portion, 81 contact member, 84 contact switch portion, 9 trigger, 90 trigger switch portion, 100 control portion, 110 setting portion

Claims

1. a bit holding portion that detachably holds a driver bit and is rotatable in a circumferential direction of the driver bit and movable in an axial direction; a first motor that rotates the bit holding portion; a position detection unit that detects a movement position of the bit holding unit along the axial direction of the driver bit; an operation switch unit that can switch between an on state and an off state; a control unit that rotates the first motor to rotate the bit holding unit, The control unit determines whether the bit holding unit has moved to an advance end position based on the movement position of the bit holding unit detected by the position detection unit, and when the bit holding unit has not reached the advance end position and a stop condition for the first motor is satisfied, stops the rotation of the first motor, drives the first motor when the operation switch unit is in an on state, and stops the first motor when the operation switch unit is in an off state, while continuing to rotate the first motor before the bit holding unit moves to the advance end position even if the operation switch unit is switched to an off state. Fastening tools.

2. The stop condition is that the rotation amount of the first motor reaches an abnormality detection rotation amount. The fastening tool according to claim 1 .

3. The stop condition is that the time from when the first motor starts rotating has reached a specified abnormality detection time. The fastening tool according to claim 1 .

4. The control unit stops the rotation of the first motor when the operation switch unit is turned off before the first motor reaches the stop condition after detecting the movement of the bit holding unit to the forward end position. The fastening tool according to any one of claims 1 to 3.

5. A bit holding part that detachably holds a driver bit and is rotatable in the circumferential direction of the driver bit and movable in the axial direction; a first motor that rotates the bit holding portion; a second motor that moves the bit holding portion along the axial direction; a position detection unit that detects a movement position of the bit holding unit along the axial direction of the driver bit; a control unit that rotates the first motor to rotate the bit holding unit and rotates the second motor to move the bit holding unit along an axial direction, The control unit determines whether the bit holding unit has moved to an advance end position based on the movement position of the bit holding unit detected by the position detection unit, and when the bit holding unit has not reached the advance end position and a stop condition for the first motor is satisfied, stops the rotation of the first motor, and determines a fastening object to be fastened with a screw engaged with a driver bit based on the rotation amount or rotation speed of the second motor, and changes the stop condition depending on the fastening object. Fastening tools.

6. A bit holding part that detachably holds a driver bit and is rotatable in the circumferential direction of the driver bit and movable in the axial direction; a first motor that rotates the bit holding portion; a second motor that moves the bit holding portion along the axial direction; a position detection unit that detects a movement position of the bit holding unit along the axial direction of the driver bit; a control unit that rotates the first motor to rotate the bit holding unit and rotates the second motor to move the bit holding unit along an axial direction, The control unit determines whether the bit holding unit has moved to an advance end position based on the movement position of the bit holding unit detected by the position detection unit, and when the bit holding unit has not reached the advance end position and a stop condition for the first motor is satisfied, stops the rotation of the first motor and starts an operation of fastening a screw into a fastening object, and changes the stop condition depending on the load applied to the first motor or the second motor via the screw. Fastening tools.

7. Equipped with an operation switch unit that can switch between an on state and an off state, The control unit drives the first motor when the operation switch unit is in an on state, and stops the first motor when the operation switch unit is in an off state, but before the bit holding unit moves to the forward end position, even if the operation switch unit is switched to an off state, continues to rotate the first motor, and determines a fastening object to be fastened with a screw engaged with a driver bit, changes the stop condition according to the fastening object, and stops the rotation of the first motor when the operation switch unit is in an off state. The fastening tool according to claim 6.

8. A bit holding part that detachably holds a driver bit and is rotatable in the circumferential direction of the driver bit and movable in the axial direction; a first motor that rotates the bit holding portion; a contact member that comes into contact with an object to be fastened by the screw engaged with the driver bit; a contact switch portion that is actuated by axial movement of the contact member and is switched between an on state and an off state; a position detection unit that detects a movement position of the bit holding unit along the axial direction of the driver bit; a control unit that rotates the first motor to rotate the bit holding unit, The control unit controls the timing to stop driving the first motor based on whether the contact switch unit is activated, and when it determines that the bit holding unit has moved to an advance end position based on the movement position of the bit holding unit detected by the position detection unit, it determines whether the contact switch unit is activated, and if the contact switch unit is in an OFF state, the first motor continues to rotate until a stop condition is met. Fastening tools.

9. The stopping condition is that the rotation amount of the first motor reaches an abnormality detection rotation amount. The fastening tool according to claim 8.

10. The stop condition is that the time from when the first motor started to rotate has reached a specified abnormality detection time. The fastening tool according to claim 8.

11. The control unit determines the movement of the bit holding unit to the forward end position, and when the contact switch unit is in the off state, stops the first motor if the contact switch unit is in the on state before the first motor reaches the stop condition. The fastening tool according to any one of claims 8 to 10.

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