Fastening tool

Abstract

The present application provides a tightening tool capable of controlling the movement end position of a screwdriver bit by moving the screwdriver bit in the direction of tightening a screw. The tightening tool (1) is provided with: a bit holding portion (3) holding a screwdriver bit (2) in a detachable manner and capable of rotating in the circumferential direction of the screwdriver bit (2) and moving in the axial direction; a bit moving motor (50) moving the bit holding portion (3) in the axial direction; and a control portion (100) controlling the position of the bit holding portion (3) in the axial direction by the number of revolutions of the bit moving motor (50), the control portion (100) performing an initialization operation of setting the standby position of the bit holding portion (3) in the axial direction and controlling the position of the bit holding portion (3) in the axial direction from the standby position by the number of revolutions of the bit moving motor.

Description

Technical Field

[0001] This invention relates to a fastening tool that engages a screwdriver bit with a screw, presses the screw against the object to be fastened by pressing the screw with the screwdriver bit, and rotates the screwdriver bit to screw it in. Background Technology

[0002] A known movable tool called a nail-driving machine is a tool that uses the air pressure of compressed air supplied from an air compressor or the combustion pressure of a gas to sequentially drive out connecting stops loaded in a nail cartridge from the front end of a screwdriver guide.

[0003] In the past, among the tools that rotate the bit to tighten the screw and move the bit in the direction of tightening the screw, an air pressure type screwdriver has been proposed, which uses a pneumatic motor to rotate the bit and uses air pressure to move the bit in the direction of tightening the screw (for example, see Patent Document 1).

[0004] In addition, a screw-driving machine has been proposed that uses the driving force of a motor that rotates the screw to compress a spring, and uses the force of the spring to drive the screw in (for example, see Patent Document 2).

[0005] Existing technical documents

[0006] Patent Document 1: Japanese Patent No. 5262461

[0007] Patent Document 2: Japanese Patent No. 6197547 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] Screwdrivers that use air pressure or spring force to drive in screws have difficulty controlling the end position of the screwdriver bit's movement by moving the bit in the direction of tightening the screw. It is difficult to control the screw head to be in a so-called coplanar state with respect to the object being tightened.

[0010] The present invention was made to solve such a problem, and its object is to provide a fastening tool that can control the end position of the screwdriver bit's movement by moving the screwdriver bit toward the fastening screw.

[0011] Technical solutions for solving the problem

[0012] To address the aforementioned issues, the present invention provides a fastening tool comprising: a bit holder for holding a screwdriver bit in a detachable manner, and capable of rotating circumferentially and moving axially; a motor for moving the bit holder axially; and a control unit for controlling the axial position of the bit holder by controlling the rotation speed of the motor. The control unit performs an initialization action to set a standby position of the bit holder axially, and controls the axial position of the bit holder from the standby position by controlling the rotation speed of the motor.

[0013] In this invention, an initialization action for setting the standby position is performed in a structure that controls the position of the bit holding part along the axial direction by the number of rotations of the motor from the standby position. This allows a standby position that serves as a reference for the end position of the screwdriver bit's movement to be set for each tool.

[0014] Furthermore, the present invention is a fastening tool comprising: a bit holding portion for holding a screwdriver bit in a detachable manner, and capable of rotating in the circumferential direction and moving in the axial direction of the screwdriver bit; a motor for rotating the bit holding portion and moving the bit holding portion in the axial direction; a contact member for contacting the object to be fastened, wherein a screw engaged with the screwdriver bit is fastened to the object to be fastened; a contact switch portion for switching on and off based on the amount of axial movement of the contact member when it contacts the object to be fastened; and a control portion for controlling the timing of stopping the drive of the motor based on the on or off state of the contact switch portion.

[0015] In this invention, it is possible to suppress the situation where the rotation or movement of the screwdriver bit ends before the screwdriver bit reaches the end position of movement.

[0016] Furthermore, the present invention is a fastening tool comprising: a bit holding portion for holding a screwdriver bit in a detachable manner, and capable of rotating in the circumferential direction and moving in the axial direction of the screwdriver bit; a motor for rotating the bit holding portion; a variation detection portion for detecting the main cause of the variation in the rotational speed of the motor; and a control portion for controlling the rotational speed of the motor to suppress the variation when the variation detection portion detects the main cause of the variation in the rotational speed of the motor.

[0017] In this invention, after the motor stops rotating, in order to prevent the screwdriver bit from screwing the screw in due to inertial rotation, the change in the motor speed is suppressed so that the screwdriver bit can stop at the end of its movement.

[0018] Furthermore, the present invention is a fastening tool comprising: a bit holder that is rotatable in the circumferential direction of a screwdriver bit and movable in the axial direction; a motor that rotates the bit holder and moves the bit holder in the axial direction; a trigger operably configured to drive the motor; a contact member that contacts the object being fastened and is movable in the axial direction; a contact arm that is movable in the axial direction in conjunction with the contact member; a position detection unit that detects the position of the contact arm that moves according to the contact member contacting the object being fastened; and a control unit that determines whether the contact arm is on or off based on the position of the contact arm detected by the position detection unit, drives the motor when both the trigger and the contact arm are on, and controls the timing of stopping the motor drive according to the on or off state of the contact arm.

[0019] Invention Effects

[0020] In this invention, the end position of the screwdriver bit's movement can be controlled by moving the screwdriver bit in the direction of tightening the screw. Attached Figure Description

[0021] Figure 1A This is a side sectional view showing an example of the internal structure of the fastening tool of this embodiment.

[0022] Figure 1B This is a top sectional view showing an example of the internal structure of the fastening tool of this embodiment.

[0023] Figure 1C This is a front sectional view showing an example of the internal structure of the fastening tool of this embodiment.

[0024] Figure 2A This is an exploded perspective view showing an example of the internal structure of the fastening tool according to this embodiment.

[0025] Figure 2B This is a perspective view showing an example of the fastening tool of this embodiment.

[0026] Figure 3A This is a perspective view showing an example of the main structure of the fastening tool according to this embodiment.

[0027] Figure 3B This is a perspective view showing an example of the main structure of the fastening tool according to this embodiment.

[0028] Figure 4A This is a cross-sectional perspective view showing an example of the main structural components of the fastening tool according to this embodiment.

[0029] Figure 4BThis is a cross-sectional perspective view showing an example of the main structural components of the fastening tool according to this embodiment.

[0030] Figure 4C This is a cross-sectional perspective view showing an example of the main structural components of the fastening tool according to this embodiment.

[0031] Figure 5 This is a top sectional view showing an example of the main structural components of the fastening tool according to this embodiment.

[0032] Figure 6A This is a top sectional view showing an example of the internal structure of the fastening tool of this embodiment.

[0033] Figure 6B This is a top sectional view showing an example of the internal structure of the fastening tool of this embodiment.

[0034] Figure 7A This is a cross-sectional view showing an example of a disassembly and assembly retention mechanism.

[0035] Figure 7B This is a cross-sectional view showing an example of a disassembly and assembly retention mechanism.

[0036] Figure 8A This is a perspective view showing an example of a disassembly and assembly retention mechanism.

[0037] Figure 8B This is a perspective view showing an example of a disassembly and assembly retention mechanism.

[0038] Figure 9 This is a perspective view showing an example of the screw feed section and the machine head of this embodiment.

[0039] Figure 10A This is a perspective view taken from the rear, showing an example of the fastening tool of this embodiment.

[0040] Figure 10B This is a perspective view taken from the rear, showing an example of the fastening tool of this embodiment.

[0041] Figure 10C This is a perspective view taken from the rear, showing an example of the fastening tool of this embodiment.

[0042] Figure 11 This is a three-dimensional diagram representing an example of a design department.

[0043] Figure 12 This is a block diagram illustrating an example of the fastening tool of this embodiment.

[0044] Figure 13A This is a side sectional view illustrating an example of the operation of the fastening tool in this embodiment.

[0045] Figure 13B This is a top sectional view showing an example of the operation of the fastening tool in this embodiment.

[0046] Figure 14 This is a flowchart illustrating an example of the operation of the fastening tool in this embodiment.

[0047] Figure 15A It is a cross-sectional view showing the tightened state of the screw.

[0048] Figure 15B This is a cross-sectional view showing the tightened state of the screw.

[0049] Figure 15C It is a cross-sectional view showing the tightened state of the screw.

[0050] Figure 16A This is an explanatory diagram illustrating an example of setting the standby positions of the holding and moving components during the first initialization operation.

[0051] Figure 16B This is an explanatory diagram illustrating an example of setting the standby positions of the holding and moving components during the first initialization operation.

[0052] Figure 16C This is an explanatory diagram illustrating an example of setting the standby positions of the holding and moving components during the first initialization operation.

[0053] Figure 16D This is an explanatory diagram illustrating an example of setting the standby positions of the holding and moving components during the first initialization operation.

[0054] Figure 17A This is an explanatory diagram illustrating an example of the action of moving the holding component and the moving component to the standby position during the second initialization operation.

[0055] Figure 17B This is an explanatory diagram illustrating an example of the action of moving the holding component and the moving component to the standby position during the second initialization operation.

[0056] Figure 17C This is an explanatory diagram illustrating an example of the action of moving the holding component and the moving component to the standby position during the second initialization operation.

[0057] Figure 18 This is a flowchart illustrating an example of selecting the first initialization action and the second initialization action.

[0058] Figure 19 This is a flowchart illustrating a variation of the operation of the fastening tool in this embodiment.

[0059] Figure 20It is a graph showing the relationship between the output of the contact switch and the control of the bit rotation motor and bit movement motor.

[0060] Figure 21 This is a flowchart illustrating another variation of the operation of the fastening tool in this embodiment.

[0061] Figure 22A It is a graph showing the relationship between the load and the control of the bit rotation motor.

[0062] Figure 22B It is a graph showing the relationship between the load and the control of the bit rotation motor.

[0063] Figure 23 This is a flowchart illustrating another variation of the operation of the fastening tool in this embodiment.

[0064] Figure 24A It is a graph showing the relationship between the rotational speed of the bit rotary motor and the bit moving motor based on feedback control.

[0065] Figure 24B It is a graph showing the relationship between the screw movement speed caused by the rotation of the bit rotary motor based on feedback control and the screw bit movement speed caused by the bit movement motor.

[0066] Figure 25 This is a flowchart illustrating another variation of the operation of the fastening tool in this embodiment.

[0067] Figure 26A It is a graph showing the relationship between the load and the control of the bit movement motor.

[0068] Figure 26B It is a graph showing the relationship between the load and the control of the bit movement motor.

[0069] Figure 27 This is a flowchart illustrating another variation of the operation of the fastening tool in this embodiment.

[0070] Figure 28 This is a side view showing another variation of the fastening tool of this embodiment.

[0071] Figure 29 This is a block diagram illustrating another variation of the fastening tool of this embodiment.

[0072] Figure 30 This is a flowchart illustrating another variation of the operation of the fastening tool in this embodiment.

[0073] Figure 31 This is a flowchart illustrating another variation of the operation of the fastening tool in this embodiment.

[0074] Figure 32 It is a graph showing the relationship between the position of the contact parts and the control of the bit rotation motor and bit movement motor.

[0075] Figure 33 This is a block diagram illustrating another variation of the fastening tool of this embodiment. Detailed Implementation

[0076] Hereinafter, embodiments of the fastening tool of the present invention will be described with reference to the accompanying drawings.

[0077] <Example of the structure of the fastening tool in this embodiment>

[0078] Figure 1A This is a side sectional view showing an example of the internal structure of the fastening tool according to this embodiment. Figure 1B This is a top sectional view showing an example of the internal structure of the fastening tool according to this embodiment. Figure 1C This is a front sectional view showing an example of the internal structure of the fastening tool according to this embodiment. Additionally, Figure 2A This is an exploded perspective view showing an example of the internal structure of the fastening tool according to this embodiment. Figure 2B This is a perspective view showing an example of the fastening tool of this embodiment.

[0079] The fastening tool 1 of this embodiment includes: a bit holding part 3 for holding a screwdriver bit 2 in a rotatable and axially movable manner; a first drive part 4 for rotating the screwdriver bit 2 held by the bit holding part 3; and a second drive part 5 for moving the screwdriver bit 2 held by the bit holding part 3 axially.

[0080] In addition, the fastening tool 1 includes: a screw storage section 6 for storing screws 200; a screw feed section 7 for feeding the screws stored in the screw storage section 6; and a head 8 for pressing against the object to be fastened by the screws 200 and for ejecting the screws.

[0081] Furthermore, the fastening tool 1 includes a tool body 10 and a handle 11. In addition, the fastening tool 1 has a battery mounting part 13 at the end of the handle 11 for the battery 12 to be installed in a detachable manner.

[0082] The tool body 10 of the fastening tool 1 extends in one direction along the axial direction of the screwdriver bit 2, as indicated by arrows A1 and A2, while the handle 11 extends in another direction intersecting the extension direction of the tool body 10. The fastening tool 1 has its front-to-back direction along the extension direction of the tool body 10, i.e., the axial direction of the screwdriver bit 2, as indicated by arrows A1 and A2. Furthermore, the fastening tool 1 has its up-and-down direction along the extension direction of the handle 11. Moreover, the fastening tool 1 has its left-to-right direction in a direction orthogonal to the extension directions of both the tool body 10 and the handle 11.

[0083] The first drive unit 4 is located on one side of the tool body 10, i.e., at the rear, across the handle 11. The second drive unit 5 is located on the other side of the tool body 10, i.e., at the front, across the handle 11.

[0084] In the screw storage section 6, multiple screws 200 are connected by a connecting band, and the connecting screws are wound in a spiral shape.

[0085] Figure 3A , Figure 3B This is a perspective view showing an example of the main structural components of the fastening tool according to this embodiment. Figures 4A to 4C This is a cross-sectional perspective view showing an example of the main structural components of the fastening tool according to this embodiment. Figure 5 This is a top sectional view showing an example of the main structure of the fastening tool according to this embodiment, detailing the bit holding part 3 and the first drive part 4. Next, the bit holding part 3 and the first drive part 4 will be described with reference to the figures.

[0086] The bit holding part 3 is an example of a front-end tool holding part, and includes: a holding member 30, which holds the screwdriver bit 2, which is an example of a front-end tool, in a detachable manner; a rotation guide member 31, which supports the holding member 30 in a manner that allows it to move in the front-back direction along the axis of the screwdriver bit 2 as indicated by arrows A1 and A2, and rotates together with the holding member 30; a moving member 32, which moves the holding member 30 in the front-back direction along the rotation guide member 31; and a force applying member 33, which applies force to the moving member 32 in the rearward direction as indicated by arrow A2.

[0087] The retaining member 30 is composed of a cylindrical component, for example, whose outer diameter is slightly smaller than the inner diameter of the rotary guide member 31 and which enters the inner side of the rotary guide member 31. The retaining member 30 has an opening 30a at its front end along the axial direction of the screwdriver bit 2, the shape of which matches the cross-sectional shape of the screwdriver bit 2. The retaining member 30 has a detachable retaining mechanism 30c at the opening 30a to detachably retain the screwdriver bit 2. The opening 30a of the retaining member 30 protrudes inside the rotary guide member 31, and the screwdriver bit 2 is detachably inserted into the opening 30a.

[0088] The rotary guide member 31 extends along the extension direction of the tool body 10, that is, in the front-to-back direction indicated by arrows A1 and A2 along the axis of the screwdriver bit 2. The rotary guide member 31 is cylindrical in shape with the retaining member 30 inserted inside, and its front end is rotatably supported by a bearing 34a, which serves as an example of a bearing, on a metal front frame 10b located on the front side of the resin housing 10a that constitutes the outer casing of the tool body 10. In addition, the rear end of the rotary guide member 31 is connected to the first drive unit 4.

[0089] The rotary guide member 31 has grooves 31a formed at two radially opposing sides, extending in the front-back direction as indicated by arrows A1 and A2 along the axial direction of the screwdriver bit 2. The rotary guide member 31 passes radially through the retaining member 30, and connecting members 30b protruding from both sides of the retaining member 30 enter the grooves 31a, thereby connecting with the retaining member 30 via the connecting members 30b.

[0090] The retaining component 30 has a through hole in a direction perpendicular to the rotation direction of the screwdriver bit 2. The connecting component 30b is inserted into this hole and fixed by a pin 30f. The connecting component 30b is a cylindrical component with an elongated oval cross-section.

[0091] The length direction of the elongated oval shape of the connecting member 30b is along the extension direction of the groove 31a, which is parallel to the axial direction of the screwdriver bit 2 indicated by arrows A1 and A2. The width direction of the elongated oval shape is orthogonal to the extension direction of the groove 31a indicated by arrows B1 and B2, that is, along the rotation direction of the rotation guide member 31. Furthermore, the width of the elongated oval shape of the connecting member 30b in the width direction, that is, 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 that direction.

[0092] Thus, the connecting member 30b entering the groove 31a is supported in the groove 31a in a manner that allows it to move axially along the rotational guide member 31. Furthermore, the movement of the connecting member 30b relative to the rotational guide member 31 in the rotational direction is restricted between one side and the other side of the groove 31a along its extending direction. Therefore, the connecting member 30b, through the rotation of the rotational guide member 31, is pushed by one side or the other side of the groove 31a according to the rotational direction of the rotational guide member 31, and receives a circumferential force from the rotational guide member 31 in the rotational direction.

[0093] Therefore, when the rotary guide member 31 rotates, the connecting member 30b is pushed by the groove 31a of the rotary guide member 31, thereby keeping the member 30 rotating together with the rotary guide member 31. In addition, the connecting member 30b is guided by the groove 31a of the rotary guide member 31, keeping the member 30 moving in the front-back direction along the axial direction of the screwdriver bit 2.

[0094] The moving member 32 is an example of a transmission member, comprising: a first moving member 32a, which rotates together with the holding member 30 to move the holding member 30 in the front-back direction along the rotation guide member 31; a second moving member 32c, which is supported on 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, which is mounted on the rear side of the second moving member 32c.

[0095] The first moving member 32a is composed of a cylindrical member, for example, whose inner diameter is slightly larger than the outer diameter of the rotary guide member 31 and extends into the outer side of the rotary guide member 31. The first moving member 32a is connected to the retaining member 30 via a connecting member 30b protruding from the groove 31a of the rotary guide member 31, thereby being supported to be movable along the axial direction of the rotary guide member 31.

[0096] Bearing 32b is an example of a bearing, inserted between the outer periphery of the first moving member 32a and the inner periphery of the second moving member 32c. The first moving member 32a constitutes an inner ring retaining member for retaining the inner ring of bearing 32b, and the second moving member 32c constitutes an outer ring retaining member for retaining the outer ring of bearing 32b. The inner ring of bearing 32b is supported on the outer periphery of the first moving member 32a in a manner that prevents rotational and axial movement, and the outer ring is supported on the inner periphery of the second moving member 32c in a manner that prevents rotational and axial movement.

[0097] Thus, the second moving member 32c, with its movement restricted in the forward and backward direction along the axial direction, is connected to the first moving member 32a via the bearing 32b. Furthermore, the second moving member 32c rotatably supports the first moving member 32a via the bearing 32b.

[0098] Therefore, the first moving member 32a is pushed by the second moving member 32c via the bearing 32b through the movement of the second moving member 32c in the front-back direction along the axial direction, and moves together with the second moving member 32c in the front-back direction along the axial direction. In addition, the first moving member 32a is rotatable relative to the second moving member 32c, while the second moving member 32c does not rotate relative to the rotation guide member 31.

[0099] In this example, the force-applying component 33 is a helical spring located outside the rotation guide component 31. It enters between the front frame 10b, which is located on the front side of the housing 10a of the tool body 10, and the second moving component 32c of the moving component 32, and abuts against the spring seat 32f, which is configured to contact the end face of the outer ring of the bearing 32b. The force-applying component 33 is compressed by the movement of the moving component 32 in the forward direction indicated by arrow A1, and a force is applied to the moving component 32 to push it in the rearward direction indicated by arrow A2.

[0100] The first drive unit 4 includes a bit rotating motor 40 and a reducer 41, both electrically driven by a battery 12. The bit rotating motor 40 is an example of a motor or a first motor. The shaft 40a of the bit rotating motor 40 is connected to the reducer 41, and the shaft 41a of the reducer 41 is connected to the rotation guide member 31. The first drive unit 4 has a structure where the reducer 41 utilizes planetary gears. The bit rotating motor 40, the rotation guide member 31, the holding member 30, and the screwdriver bit 2 held in the holding member 30 are arranged coaxially.

[0101] The first drive unit 4 has a bit rotary motor 40 and a reducer 41 mounted on a metal rear frame 10c located at the rear of the housing 10a of the tool body 10. The shaft 41a of the reducer 41 is supported on 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, which is also supported on the rear frame 10c via a bearing 42. Thus, the rotation guide member 31 is rotatably supported via the bearing 42, which is an example of a bearing.

[0102] The bit holding part 3 and the first drive part 4 are assembled into one unit by connecting the front frame 10b and the rear frame 10c via a connecting part 10d extending in the front-rear direction. The front frame 10b is fixed to the housing 10a of the tool body 10 by screws 10e.

[0103] Furthermore, the front end of the rotating guide member 31 of the bit holder 3 is supported on the front frame 10b fixed to the front side of the housing 10a of the tool body 10 via a bearing 34a, and the rear end of the rotating guide member 31 is supported on the rear frame 10c fixed to the rear side of the housing 10a via the shaft 41a of the reducer 41 and a bearing 42. Thus, the rotating guide member 31 of the bit holder 3 is rotatably supported on the tool body 10.

[0104] Thus, the first drive unit 4 rotates the rotation guide member 31 via the bit rotation motor 40. When the rotation guide member 31 rotates, the connecting member 30b is pushed by the groove 31a of the rotation guide member 31, thereby keeping the retaining member 30 of the screwdriver bit 2 rotating together with the rotation guide member 31.

[0105] In the bit holding part 3, a guide member 32g is provided in the second moving member 32c. A pair of guide wall parts 10g are provided in the connecting member 10d at a distance slightly larger than the diameter of the guide member 32g. The guide member 32g enters between the pair of guide wall parts 10g, so that the pair of guide wall parts 10g face the circumferential surface of the guide member 32g.

[0106] Thus, the guide member 32g is guided by the connecting member 10d, and the second moving member 32c is able to move in the forward and backward directions indicated by arrows A1 and A2 along the axis of the screwdriver bit 2, and the rotation of the second moving member 32c following the rotation of the rotating guide member 31 is restricted.

[0107] Figure 6A and Figure 6B This is a top sectional view showing an example of the internal structure of the fastening tool according to this embodiment, showing details of the second drive unit 5. Next, the second drive unit 5 will be described with reference to the figures.

[0108] The second drive unit 5 includes a bit-moving motor 50 and a reducer 51, both electrically driven by a battery 12. The bit-moving motor 50 is an example of a motor or a second motor. The shaft 50a of the bit-moving motor 50 is connected to the reducer 51, and the shaft 51a of the reducer 51 is connected to a pulley 52, which serves as a transmission component. The pulley 52 of the second drive unit 5 is supported on the tool body 10 via a bearing 53. The shaft 50a of the bit-moving motor 50 of the second drive unit 5 is arranged along the extending direction of the handle 11.

[0109] In the second drive unit 5, one end of a linear wire 54, which serves as a transmission component, is connected to a pulley 52, and the wire 54 is wound onto the pulley 52 by its rotation. The other end of the wire 54 is connected to a wire connection portion 32h provided in the second moving member 32c of the moving member 32.

[0110] Therefore, the second drive unit 5 rotates the pulley 52 via the bit movement motor 50 to wind the wire 54, thereby causing the second moving member 32c to move forward in the direction indicated by arrow A1. In the bit holding unit 3, the second moving member 32c moves forward, pushing the first moving member 32a via the bearing 32b, causing the first moving member 32a and the second moving member 32c to move together in the forward direction along the axial direction. The first moving member 32a moves forward, causing the holding member 30, which is connected to the first moving member 32a via the connecting member 30b, to move forward, and the screwdriver bit 2 held by the holding member 30 moves in the forward direction indicated by arrow A1.

[0111] The second drive unit 5 is positioned such that the tangential direction of the portion of the pulley 52 where the wire 54 is wound is along the extending direction of the rotary guide member 31, and is offset to one side approximately from the center in the left-right direction of the fastening tool 1. That is, the center of the pulley 52, in this example the shaft 50a of the bit movement motor 50, is offset to one side relative to the rotary guide member 31, and when viewed from the axial direction of the pulley 52, the portion 52a where the wire 54 is wound on the pulley 52 is arranged to overlap with the rotary guide member 31.

[0112] In addition, such as Figure 6A , Figure 6B As shown, the wire 54 between the pulley 52 and the second moving part 32c is parallel to the axial direction of the rotation guide part 31 in the radial direction of the pulley 52, and as... Figure 1A As shown, the pulley 52 and the like are also arranged parallel to the axis of the rotation guide member 31 in the axial direction of the bit moving motor 50, which is radially orthogonal to the pulley 52.

[0113] Furthermore, when the wire 54 is wound overlappingly around the pulley 52, the distance from the center of the pulley 52 to the wire 54 varies depending on the number of windings, thus changing the amount of movement of the screwdriver bit 2 when the pulley 52 rotates one revolution. In addition, the angle between the direction in which the wire 54 extends between the pulley 52 and the second moving member 32c and the direction of movement of the screwdriver bit 2 along the axial direction of the rotation guide member 31 changes.

[0114] Therefore, the diameter of pulley 52 is set so that the rotation amount α of pulley 52 required to move screwdriver bit 2 by a predetermined amount is less than 360°.

[0115] Therefore, in order to move the screwdriver bit 2 by a predetermined amount, during the action of the pulley 52 winding the wire 54, such as Figure 6B As shown, the wire 54 is wound around the pulley 52 without overlapping, which can suppress inaccurate movement of the screwdriver bit 2. In addition, it can suppress changes in the parallelism between the direction in which the wire 54 extends between the pulley 52 and the second moving member 32c and the direction of movement of the screwdriver bit 2 along the axial direction of the rotation guide member 31.

[0116] Therefore, the relationship between the rotation speed of the bit movement 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. The amount of movement of the holding member 30 along the axial direction of the rotation guide member 31 can be controlled by controlling the rotation speed of the bit movement motor 50. That is, the amount of movement of the screwdriver bit 2 mounted on the holding member 30 can be controlled by controlling the rotation speed of the bit movement motor 50.

[0117] Furthermore, regardless of the amount of wire 54 wound, the tension applied to the wire 54 is always parallel to the direction of movement of the screwdriver bit 2 along the axial direction of the rotating guide member 31, which can suppress the movement of the screwdriver bit 2 and reduce the efficiency of force transmission for pushing the screw 200 through the screwdriver bit 2.

[0118] Therefore, the wire 54 between the pulley 52 and the second moving member 32c extends in a straight line along the moving direction of the moving member 32, which can suppress the increase of load when the wire 54 is wound by the pulley 52 and the increase of load when the wire 54 is pulled out from the pulley 52.

[0119] Furthermore, because the wire 54 is flexible enough to be wound around the pulley 52, it is impossible to push the second moving member 32c to move the moving member 32 backward. Therefore, a force-applying member 33 is provided, which is compressed by the moving member 32 moving in the forward direction as shown by arrow A1, and applies a force to the moving member 32 to push it in the rearward direction as shown by arrow A2. Thus, in the structure in which the screwdriver bit 2 is advanced by winding the wire 54 around the pulley 52, the screwdriver bit 2 can be retracted after it has advanced.

[0120] In addition, the retaining member 30 that holds the screwdriver bit 2 is supported in a manner that allows it to move in the front-back direction relative to the rotating guide member 31 by engaging with the connecting member 30b provided in the retaining member 30 and the slot 31a provided in the rotating guide member 31, and rotates together with the rotating guide member 31.

[0121] Therefore, by configuring the bit rotation motor 40, the rotation guide member 31, the holding member 30, and the screwdriver bit 2 held in the holding member 30 on the same axis, it is possible to achieve a structure in which the screwdriver bit 2 can be rotated and moved in the front-back direction without moving the bit rotation motor 40 in the front-back direction.

[0122] In addition, in a structure in which the bit rotation motor 40 and the screwdriver bit 2 are arranged on the same axis, it is conceivable that the rotation of the bit rotation motor 40 can be converted into the forward and backward movement of the screwdriver bit 2 by using a feed screw.

[0123] However, in the structure that uses a feed screw, the forward distance of the screwdriver bit 2 per revolution of the motor cannot be large. Therefore, even if the motor speed is increased, it is difficult to speed up the movement of the screwdriver bit 2.

[0124] In fastening tool 1, in order to shorten the time it takes to press the screw 200 onto the object to be fastened with the screwdriver bit 2, it is necessary to speed up the movement of the screwdriver bit 2. However, in the structure using the feed screw, it is difficult to shorten the time until the screw 200 is pressed onto the object to be fastened with the screwdriver bit 2.

[0125] In contrast, in a structure where the holding member 30 holding the screwdriver bit 2 is supported in a manner that allows it to move in the front-to-back direction relative to the rotation guide member 31, and the second drive unit 5 rotates the pulley 52 to wind the wire 54, causing the holding member 30 to move in the forward direction, the moving speed of the screwdriver bit 2 can be increased according to the rotational speed of the bit moving motor 50. This shortens the time required to press the screw 200 onto the object being fastened using the screwdriver bit 2.

[0126] Figure 7A , Figure 7B This is a cross-sectional view showing an example of a disassembly and assembly retention mechanism. Figure 8A , Figure 8B This is a perspective view showing an example of a disassembly and assembly retention mechanism, illustrating the details of the disassembly and assembly retention mechanism 30c. The disassembly and assembly retention mechanism 30c will now be explained with reference to the figures.

[0127] The disassembly and assembly retaining mechanism 30c includes a ball 30d protruding from the opening 30a and a spring 30e that applies force to the ball 30d in the direction of its protrusion into the opening 30a. The spring 30e is a ring-shaped leaf spring and is fitted into the outer periphery of the retaining member 30.

[0128] When the screwdriver bit 2 is inserted into the opening 30a of the retaining member 30, the disassembly and assembly retaining mechanism 30c causes the ball 30d, which is pushed by the insertion part 20, to deform the spring 30e in the direction that increases the diameter of the annular spring 30e, while retracting towards the outer periphery of the retaining member 30.

[0129] When the insertion portion 20 of the screwdriver bit 2 is inserted into the opening 30a of the retaining member 30 to the position where the groove 20a formed on the outer periphery of the insertion portion 20 faces the ball 30d, the ball 30d, which is stressed by the spring 30e, becomes engaged in the groove 20a. This prevents the screwdriver bit 2 from being accidentally pulled out of the retaining member 30.

[0130] Furthermore, when a predetermined force or more is applied in the direction of pulling the screwdriver bit 2 out of the retaining member 30, the spring 30e is deformed in the direction of increasing the diameter of the annular spring 30e, and the ball 30d is retracted, thereby enabling the screwdriver bit 2 to be pulled out of the retaining member 30.

[0131] During the insertion and removal of the screwdriver bit 2's insertion portion 20 relative to the opening 30a of the retaining member 30, the ball 30d retracts towards the outer periphery of the retaining member 30. Therefore, space is required for the ball 30d to retract on the outer periphery of the retaining member 30. On the other hand, since the retaining member 30 is inserted into the cylindrical rotation guide member 31, space for the ball 30d to retract cannot be guaranteed between the outer periphery of the retaining member 30 and the inner periphery of the rotation guide member 31.

[0132] Furthermore, when the diameter difference between the retaining member 30 and the rotating guide member 31 is set to ensure space for the ball 30d to retract between the outer periphery of the retaining member 30 and the inner periphery of the rotating guide member 31, the outer diameter of the retaining member 30 cannot be reduced since the radial dimension of the screwdriver bit 2 is already determined. Therefore, the outer diameter of the rotating guide member 31 needs to be increased. Consequently, the device becomes larger.

[0133] In contrast, the rotary guide member 31 is provided with a groove 31a for guiding the connecting member 30b. The groove 31a extends from the inner circumference of the rotary guide member 31 to the outer circumference and extends along the axial direction of the rotary guide member 31.

[0134] Therefore, in the disassembly and assembly retaining mechanism 30c, the ball 30d is positioned corresponding to the groove 31a of the rotary guide member 31. That is, the connecting member 30b of the retaining member 30 and the ball 30d of the disassembly and assembly retaining mechanism 30c are coaxially arranged along the axial direction of the rotary guide member 31. Thus, in either the rotation of the rotary guide member 31 and the retaining member 30, or the axial movement of the retaining member 30 relative to the rotary guide member 31, the ball 30d is exposed in the groove 31a of the rotary guide member 31.

[0135] Therefore, through the insertion and removal action of the screwdriver bit 2's insertion portion 20 relative to the opening 30a of the retaining member 30, the ball 30d, which retracts towards the outer periphery of the retaining member 30, enters the groove 31a of the rotation guide member 31.

[0136] Therefore, in the structure where the retaining member 30 is inserted into the cylindrical rotary guide member 31, space can be ensured for the ball 30d of the co-installed retaining mechanism 30c to retract. In addition, by using the groove 31a for the connecting member 30b to enter as a space for the ball 30d to retract, the area of ​​the opening provided in the rotary guide member 31 is reduced, and strength can be ensured.

[0137] Furthermore, it is not necessary to increase the diameter difference between the retaining member 30 and the rotating guide member 31 to ensure the space for the ball 30d to retreat between the outer periphery of the retaining member 30 and the inner periphery of the rotating guide member 31, thus suppressing the enlargement of the device.

[0138] Figure 9 This is a perspective view showing an example of the screw feed section and machine head 8 of this embodiment, showing details of the screw feed section 7 and the machine head 8. Next, the screw feed section 7 and the machine head 8 will be described with reference to the respective figures.

[0139] The screw feed unit 7 includes: a screw feed motor 70, a pinion 71 mounted on the shaft of the screw feed motor 70 via a reducer, a rack 72 meshing with the pinion 71, and a locking part 73 connected to the rack 72 and engaged with a connecting screw fed from the screw storage unit 6.

[0140] The rack 72 of the screw feed unit 7 is supported in such a way that it can move vertically along the feed direction of the connecting screw. The screw feed unit 7 feeds the connecting screw by moving the engagement part 73, which engages with the connecting screw, vertically when the screw feed motor 70 rotates forward and reverse.

[0141] The head unit 8 includes: an injection passage 80 through which screws 200 are supplied via a screw feed section 7 and through which screwdriver bits 2 pass; a contact member 81 having an injection outlet 81a communicating with the injection passage 80 and contacting the object to be fastened; a contact arm 82 that moves in a front-rear direction in conjunction with the contact member 81; and an adjustment section 83 that limits the amount of movement of the contact arm 82. Additionally, the head unit 8 includes a cover member 88 that can be opened and closed to cover the path through which the screws 200 pass from the screw storage section 6 to the injection passage 80.

[0142] The fastening tool 1 assembles the components constituting the injection passage 80, the contact member 81, and the contact arm 82 to form the head 8, and fixes it to the front frame 10b and the head body 10f constituting the tool body 10. In addition, the fastening tool 1 has a contact switch 84 that is actuated by being pushed by the contact arm 82.

[0143] In the head section 8, the contact member 81 is supported in a manner that allows it to move in the front-back direction as indicated by arrows A1 and A2, and the contact arm 82 moves in the front-back direction in conjunction with the contact member 81. In the head section 8, the contact member 81 is subjected to a force in the forward direction by a force-applying member (not shown), and the contact member 81, which has been pushed backward by the fastening object, is subjected to a force in the forward direction by the force-applying member.

[0144] In the machine head 8, the contact member 81 is pressed by the object being fastened, causing the contact arm 82 to move backward. The adjustment unit 83 adjusts the amount of movement of the contact arm 82 until the contact switch unit 84 is activated. The contact switch unit 84 switches between working and not working by being pushed by the contact arm 82. In this example, the state in which the contact switch unit 84 is not working when it is not pushed by the contact arm 82 is defined as the contact switch unit 84 being open, and the state in which the contact switch unit 84 is working when it is pushed by the contact arm 82 is defined as the contact switch unit 84 being on.

[0145] Next, the structure related to the control and operation of the fastening tool 1 will be described with reference to the figures. The fastening tool 1 includes a trigger 9 that receives operation and a trigger switch 90 that operates through the operation of the trigger 9. The trigger 9 is located on the front side of the handle 11 and is configured to be operated by the fingers of the hand holding the handle 11. The trigger switch 90 is activated by being pushed by the trigger 9.

[0146] The trigger switch 90 is switched on and off by being pushed by the trigger 9. In this example, the state in which the trigger 9 is not operated and the trigger switch 90 is not pushed by the trigger 9 and therefore does not operate is set as the state in which the trigger switch 90 is off, and the state in which the trigger 9 is operated and the trigger switch 90 is pushed by the trigger 9 and therefore operates is set as the state in which the trigger switch 90 is on.

[0147] The fastening tool 1 includes a control unit 100, which controls the first drive unit 4, the second drive unit 5, and the screw feed unit 7 based on the outputs of the trigger switch unit 90, which operates through the operation of the trigger 9, and the contact switch unit 84, which operates by being pushed by the contact member 81.

[0148] The control unit 100 is composed of a substrate on which various electronic components are mounted. Between the screw storage unit 6 and the handle 11, a substrate storage unit 111 is provided on the back side of the screw storage unit 6.

[0149] In power tools that are used with the handle held by hand, a storage section for consumables such as screws is located at the front of the handle. Furthermore, space is required between the handle and the storage section for the fingers to fit in order to grip the handle.

[0150] Therefore, the fastening tool 1 utilizes the space between the screw storage part 6 and the handle 11 to provide a substrate storage part 111 on the back side of the screw storage part 6.

[0151] In power tools used by holding the handle by hand, a structure has been proposed in which a battery is installed at the bottom of the handle and a base plate is placed between the handle and the battery. With such a structure, the vertical dimension of the power tool along the extension direction of the handle is increased.

[0152] In contrast, by providing a substrate storage portion 111 on the back side of the screw storage portion 6, the size of the fastening tool 1 in the vertical direction along the extension direction of the handle 11 can be suppressed. Furthermore, since the screw storage portion 6 houses the connecting screw wound in a spiral shape, the surface of the screw storage portion 6 facing the handle 11 is approximately circular. This prevents the fastening tool 1 from becoming too large and ensures the volume of the substrate storage portion 111.

[0153] Figures 10A to 10C This is a perspective view from the rear, showing an example of the fastening tool according to this embodiment. Figure 11 This is a perspective view showing an example of the setting unit, illustrating details of the setting unit 110. Next, the setting unit 110 will be explained with reference to the figures.

[0154] The fastening tool 1 includes a second drive unit 5 that moves the screwdriver bit 2 in the forward and backward direction along the axial direction. The second drive unit 5 is driven by a bit movement motor 50 and is a structure in which a moving member 32 connected to a pulley 52 that is driven to rotate by the bit movement motor 50 is connected to a wire 54 and a holding member 30 connected to the moving member 32 moves along the rotation guide member 31 in the forward direction along the axial direction of the screwdriver bit 2.

[0155] Therefore, the amount of movement (forward movement) of the screwdriver bit 2 can be controlled by controlling the rotation speed of the bit movement motor 50. That is, the bit movement motor 50 can be rotated in conjunction with the rotation of the bit rotation motor 40, which rotates the screwdriver bit 2 in the direction of tightening the screw 200, and the forward movement of the screwdriver bit 2, which follows the screw 200 as it is tightened, can be controlled by controlling the rotation speed of the bit movement motor 50, thereby controlling the stop position of the screwdriver bit 2 along the axial direction.

[0156] Therefore, the fastening tool 1 includes a setting section 110 for setting the advance amount of the screwdriver bit 2. The setting section 110 is an example of a setting unit, configured to allow selection of any setting value from a plurality of setting values, or to allow stepless selection of any setting value.

[0157] In this example, the setting unit 110 is structured so that the setting value is selected by an operation unit 110a consisting of buttons. Alternatively, the operation unit 110a may also be structured so that the setting value is selected by a rotary dial. In addition, the setting unit 110 may also be structured so that the selected setting value is displayed by means of a label or engraving, or by means of a display unit 110b such as an LED, so that the operator can easily grasp the current setting value.

[0158] The setting part 110 is provided in the base plate storage part 111 provided on the back side of the screw storage part 6, and is respectively provided on the left and right sides of the surface facing the handle 11.

[0159] Therefore, when observing the fastening tool 1 from the rear, the setting section 110 can be visually confirmed from the left and right sides of the handle 11.

[0160] When using the screwdriver by holding the handle 11, the side of the screw storage section 6 facing the handle 11 faces the operator holding the fastening tool 1. Therefore, by providing a setting section 110 on the side of the base plate storage section 111 on the back side of the screw storage section 6 facing the handle 11, the display section 110b provided on the setting section 110 is easily visible. This reduces the possibility of the operator missing the display. Furthermore, the information displayed on the display section 110b includes, in addition to the screw depth setting value determined by the advance amount of the screwdriver bit 2, the power on / off status, the operating mode selected from various selectable operating modes, the presence or absence of screws, the remaining screw weight, and any abnormalities.

[0161] Furthermore, when using the handle 11 by hand, the operation section 110a, including buttons on the setting section 110, is easily visible. Therefore, while holding the handle 11 with one hand, the operation section 110a can be visually checked while the other hand is used to operate it, allowing for reliable operation.

[0162] Furthermore, the substrate that constitutes the control unit 100 is housed in the substrate storage section 111. In this substrate, by mounting switches or the like that constituting the operation section 110a and lamps or the like that constituting the display section 110b on the side facing the handle 11, it is possible to omit the substrate for the setting section 110 that is provided outside the control unit 100.

[0163] Figure 12 This is a block diagram illustrating an example of the fastening tool according to this embodiment. As described above, the fastening tool 1 includes a second drive unit 5 that moves the screwdriver bit 2 in a forward-backward direction along the axial direction. The second drive unit 5 is driven by a bit movement motor 50. A holding member 30 on which the screwdriver bit 2 is mounted is connected to a moving member 32, which is connected to a pulley 52 that is driven to rotate by the bit movement motor 50 via a wire 54. Furthermore, the holding member 30 and the moving member 32 are configured to move forward along the axial direction of the screwdriver bit 2 along the rotation guide member 31.

[0164] Therefore, the control unit 100 can control the amount of movement (forward movement) of the screwdriver bit 2 by controlling the rotation speed of the bit movement motor 50. That is, the bit movement motor 50 is rotated in conjunction with the rotation of the bit rotation motor 40, which rotates the screwdriver bit 2 in the direction of tightening the screw 200. Thus, the forward movement of the screwdriver bit 2, which follows the screw 200 as it is tightened, can be controlled by the rotation speed of the bit movement motor 50, thereby controlling the stop position of the screwdriver bit 2 along the axial direction.

[0165] Furthermore, the control unit 100 sets the rotation speed of the bit movement motor 50, which determines the forward advance of the screwdriver bit 2, using the setting unit 110. Moreover, the control unit 100 controls whether the bit movement motor 50 of the second drive unit 5 and the bit rotation motor 40 of the first drive unit 4 are driven based on combinations of the on / off states of the contact switch unit 84 and the trigger switch unit 90.

[0166] <Example of the operation of the fastening tool in this embodiment>

[0167] Figure 13A This is a side sectional view illustrating an example of the operation of the fastening tool according to this embodiment. Figure 13B This is a top sectional view illustrating an example of the operation of the fastening tool according to this embodiment. Figure 14This is a flowchart illustrating an example of the operation of the fastening tool according to this embodiment. Next, the fastening operation of the fastening tool according to this embodiment will be explained with reference to the figures.

[0168] Fastening tool 1 is in standby mode, such as Figure 1A As shown, the front end of the screwdriver bit 2 is located in the standby position P1 behind the injection passage 80, and can supply screws 200 to the injection passage 80.

[0169] Control unit 100 Figure 14 In step SA1, the rotation speed of the bit movement motor 50, which determines the advance amount of the screwdriver bit 2, is set according to the setting value selected by the setting unit 110. When the contact member 81 is pressed against the object being fastened, the contact switch 84 is pushed by the contact arm 82. In step SA2, the contact switch 84 is turned on, and the trigger 9 is activated. In step SA3, when the trigger switch 90 is turned on, the bit rotation motor 40 of the first drive unit 4 is driven in step SA4, and the bit movement motor 50 of the second drive unit 5 is driven in step SA5.

[0170] When the bit movement motor 50 is driven to rotate in the positive direction, the pulley 52 rotates in the positive direction, thereby winding the wire 54 onto the pulley 52. ​​By winding the wire 54 onto the pulley 52, the second moving part 32c, connected to the wire 54, is guided by the rotation guide part 31 to move forward in the axial direction. As the second moving part 32c moves forward, the first moving part 32a is pushed by the second moving part 32c via the bearing 32b, and together with the second moving part 32c, compresses the force-applying part 33 and moves it forward in the axial direction.

[0171] When the first moving part 32a moves forward, the connecting part 30b of the holding part 30, which is connected to the first moving part 32a via the connecting part 30b, is guided by the groove 31a of the rotation guide part 31, thereby moving the holding part 30 forward along the axial direction of the screwdriver bit 2.

[0172] As a result, the screwdriver bit 2 held in the holding member 30 moves forward in the direction indicated by arrow A1, engages with the screw 200 supplied to the ejection port 81a of the head 8, and causes the screw 200 to move forward and press against the object to be fastened.

[0173] Furthermore, when the bit rotation motor 40 is driven to rotate in the positive direction, the rotation guide member 31 rotates in the positive direction. When the rotation guide member 31 rotates in the positive direction, the connecting member 30b connected to the holding member 30 is pushed by the groove 31a of the rotation guide member 31, thereby keeping the member 30 and the rotation guide member 31 rotating together.

[0174] Therefore, the screwdriver bit 2 held in the holding member 30 rotates the screw 200 in the positive direction (clockwise) and screws it into the object to be fastened. The control unit 100, in conjunction with the operation of rotating the screwdriver bit 2 by the first drive unit 4 to screw the screw into the object to be fastened, moves the screwdriver bit 2 forward by the second drive unit 5 according to the load applied to the bit rotation motor 40, the rotation speed of the bit rotation motor 40, the load applied to the bit movement motor 50, the rotation speed of the bit movement motor 50, etc., so that the screwdriver bit 2 follows the screw being screwed into the object to be fastened.

[0175] In step SA6, the control unit 100 determines that the rotational speed of the bit movement motor 50 has reached the set value selected by the setting unit 110. Figure 13A , Figure 13B As shown, when the front end of the screwdriver bit 2 reaches the set end position P2, the drive of the bit rotation motor 40 is stopped in step SA7, and after the bit movement motor 50 stops rotating in the positive direction in step SA8, the bit movement motor 50 is reversed in step SA9.

[0176] When the bit moving motor 50 rotates in the opposite direction, the pulley 52 rotates in the opposite direction, thereby pulling the wire 54 out of the pulley 52. ​​As the wire 54 is pulled out of the pulley 52, the second moving part 32c moves forward, thereby extending the compressed force-applying part 33 and pushing the second moving part 32c backward.

[0177] The second moving part 32c is pushed rearward by the force-applying part 33, and thus guided by the rotation guide part 31 to move in the rearward direction along the axial direction. When the second moving part 32c moves rearward, the first moving part 32a is pulled by the second moving part 32c via the bearing 32b, and moves together with the second moving part 32c in the rearward direction along the axial direction.

[0178] When the first moving part 32a moves in the rearward direction, the connecting part 30b of the holding part 30, which is connected to the first moving part 32a via the connecting part 30b, is guided by the groove 31a of the rotation guide part 31, and the holding part 30 moves in the rearward direction along the axial direction of the screwdriver bit 2.

[0179] In step SA10, when the bit moving motor 50 reverses to the initial position where a predetermined amount of wire 54 is pulled out from the pulley 52, and the holding member 30 and the moving member 32 move backward to the front end of the screwdriver bit 2 and return to the standby position P1, the control unit 100 stops the reverse rotation of the bit moving motor 50 in step SA11.

[0180] Furthermore, the moving member 32 has a cushioning member 32d made of rubber or the like on the rear side of the second moving member 32c. This prevents the second moving member 32c from directly contacting the rear frame 10c during its rearward movement, thus suppressing noise generation and damage. When the trigger switch 90 is off, the control unit 100 rotates the screw feed motor 70 in one direction, causing the engaging part 73 to descend. When the engaging part 73 descends to the position where it engages with the next screw 200, the control unit 100 reverses the screw feed motor 70, causing the engaging part 73 to rise and supply the next screw 200 to the injection passage 80.

[0181] Figures 15A-15C This is a cross-sectional view showing the tightened state of the screws. Figure 15A This refers to a state where the head 201 of the screw 200 does not rise from or sink into the surface of the object 202 being fastened, a state known as coplanarity. Figure 15B This indicates that the head 201 of the screw 200 is raised from the object 202 being fastened. Figure 15C This indicates that the head 201 of the screw 200 is embedded in the object 202 being fastened.

[0182] When the tightening tool 1 reaches the end position P2 at the tip of the screwdriver bit 2, and the screw 200 is a countersunk screw, if... Figure 15A As shown, it is preferable to set the advance amount of the screwdriver bit 2 so that the surface of the head 201 of the screw 200 is in a so-called coplanar state with the surface of the object being fastened 202. Furthermore, the screw 200 is not limited to countersunk screws; it can be any type of screw, such as a pan head screw, terminal screw, or truss screw. In this case, it is preferable to set the advance amount of the screwdriver bit 2 so that the seat surface of the head 201 of the screw 200 contacts the surface of the object being fastened 202, preventing the head 201 of the screw 200 from lifting off the object being fastened 202.

[0183] When the tip of the screwdriver bit 2 reaches the end position P2, the head 201 of the screw 200... Figure 15B When the screwdriver bit 2 is in a state where it is lifted from the fastened object 202, the setting unit 110 sets the movement amount (forward amount) of the screwdriver bit 2. The forward amount of the screwdriver bit 2 is increased by increasing the rotation speed (rotation amount) of the bit movement motor 50, causing the operation end position P2 to advance. On the other hand, at the head 201 of the screw 200... Figure 15C When the screwdriver bit 2 is embedded in the fastening object 202, the setting unit 110 sets the movement amount (forward amount) of the screwdriver bit 2. By reducing the rotation speed of the screwdriver bit moving motor 50, the forward amount of the screwdriver bit 2 is reduced, and the operation end position P2 is moved back.

[0184] As described above, the amount of movement (forward movement) of the screwdriver bit 2 is determined by the rotation speed of the bit movement motor 50. Furthermore, starting from the initial position of the screwdriver bit 2, i.e., the standby position P1, the bit movement motor 50 is rotated to the number of revolutions set by the setting unit 110, and then the bit movement motor 50 is stopped or reversed, thereby controlling the operation to the end position P2. Therefore, the screwing depth can be adjusted.

[0185] Thus, in order to advance the front end of the screwdriver bit 2 held in the holding member 30 by a predetermined amount based on the predetermined standby position P1 and the rotation speed of the bit movement motor 50, the standby positions of the holding member 30 on which the screwdriver bit 2 is mounted and the moving member 32 that moves the holding member 30 are set. The action of setting the standby positions of the holding member 30 and the moving member 32 is called the first initialization action.

[0186] Furthermore, before the driving and tightening actions begin, the holding member 30 and the moving member 32 are moved to a set standby position. Based on this standby position, the position of the holding member 30 and the moving member 32 is controlled by the rotation speed of the bit movement motor 50. Then, the holding member 30 and the moving member 32 are moved from the set standby position to a predetermined movement amount (advance) to perform the tightening action. The action of moving the holding member 30 and the moving member 32 to the standby position set in the first initialization action is called the second initialization action.

[0187] As a unit for setting the standby position of the holding member 30 and the moving member 32 in the first initialization operation, it is conceivable to use a unit with a sensor or a unit based on the maximum position of the range of forward and backward movement of the holding member 30 and the moving member 32. When using a sensor, the sensor's detection position or a position moved by a predetermined amount from the detection position is set as the standby position.

[0188] In addition, when using the maximum position of the range that can move back and forth, the position in which the holding member 30 and the moving member 32 have moved a predetermined amount from the front position or the rear position is set as the standby position.

[0189] Figures 16A to 16D This is an explanatory diagram illustrating an example of setting the standby positions of the holding member and the moving member during the first initialization operation. Next, the operation of setting the standby positions of the holding member 30 and the moving member 32 will be explained. Furthermore, in Figures 16A to 16D The example shown is an action of setting the standby position by using the maximum position of the range that the holding member 30 and the moving member 32 can move back and forth.

[0190] like Figure 16AAs shown, the control unit 100 starts from a state where the holding member 30 and the moving member 32 are in any position, and rotates the bit moving motor 50 in the positive direction. When the bit moving motor 50 rotates in the positive direction, the wire 54 is wound onto the pulley 52, thereby moving the moving member 32 and the holding member 30 connected to the moving member 32 move forward along the axis of the screwdriver bit 2 along the rotation guide member 31.

[0191] like Figure 16B As shown, when the bit moving motor 50 rotates forward and the holding member 30 and the moving member 32 move to the front end position PF, which is the end position on one side, the control unit 100 stops the forward rotation of the bit moving motor 50 and moves the holding member 30 and the moving member 32 to the front end position PF.

[0192] Next, the control unit 100 rotates the bit movement motor 50 in the opposite direction. When the bit movement motor 50 reverses, the wire 54 is pulled out from the pulley 52, thereby the moving part 32 is pushed backward by the force application member 33, and the moving part 32 and the holding member 30 connected to the moving part 32 move backward along the rotation guide member 31 along the axis of the screwdriver bit 2.

[0193] like Figure 16C As shown, when the bit moving motor 50 reverses to the rear end position PE, which is the end position on the other side, the control unit 100 stops the reverse rotation of the bit moving motor 50 and moves the holding member 30 and the moving member 32 to the rear end position PE by applying force through the force application member 33.

[0194] The control unit 100 obtains the amount of movement of the holding member 30 and the moving member 32 from the front position PF to the rear position PE as the overall distance L1. The amount of movement from the front position PF to the rear position PE is calculated based on the rotational speed of the bit moving motor 50.

[0195] The control unit 100 presets the movement amount of the holding component 30 and the moving component 32 from the standby position to the front position PF as the target movement amount L2. The control unit 100 sets the difference between the total distance L1 from the front position PF to the rear position PE and the preset target movement amount L2 as the standby position movement amount L3, and stores it. The standby position movement amount L3 is the movement amount of the holding component 30 and the moving component 32 from the rear position PE.

[0196] like Figure 16DAs shown, the control unit 100 rotates the bit movement motor 50 forward, causing the holding member 30 and the moving member 32 to move forward from the rear position PE. When the control unit 100 rotates the bit movement motor 50 forward by a number of revolutions equivalent to the standby position movement amount L3, it stops the forward rotation of the bit movement motor 50, moves the holding member 30 and the moving member 32 to the standby position, and moves the front end of the screwdriver bit 2 held in the holding member 30 to the standby position P1.

[0197] Furthermore, when the holding member 30 and the moving member 32 are moved to the front position PF and the rear position PE, and when the second moving member 32c comes into contact with the buffer member 32d, it is preferable to drive them at a low speed that does not affect the durability of the tool.

[0198] Figures 17A-17C This is an explanatory diagram illustrating an example of the action of moving the holding member and the moving member to the standby position during the second initialization operation. Next, the action of moving the holding member 30 and the moving member 32 to the preset standby position will be explained.

[0199] like Figure 17A As shown, the control unit 100 rotates the bit movement motor 50 in the opposite direction from a state where the holding member 30 and the moving member 32 are in any position. When the bit movement motor 50 reverses, the wire 54 is pulled out from the pulley 52, the moving member 32 is pushed backward by the force application member 33, and the moving member 32 and the holding member 30 connected to the moving member 32 move backward along the axis of the screwdriver bit 2 along the rotation guide member 31.

[0200] like Figure 17B As shown, when the bit moving motor 50 reverses to the point where the holding member 30 and the moving member 32 move to the rear end position PE, the control unit 100 stops the reverse rotation of the bit moving motor 50 and moves the holding member 30 and the moving member 32 to the rear end position PE by applying force through the force application member 33.

[0201] like Figure 17C As shown, the control unit 100 rotates the bit movement motor 50 forward, causing the holding member 30 and the moving member 32 to move forward from the rear position PE. When the control unit 100 rotates the bit movement motor 50 forward by a number of revolutions equivalent to the standby position movement amount L3, it stops the forward rotation of the bit movement motor 50, moves the holding member 30 and the moving member 32 to the standby position, and moves the front end of the screwdriver bit 2 held in the holding member 30 to the standby position P1.

[0202] exist Figures 16A to 16DIn the first initialization action described in the text, the action of setting the standby position of the holding component 30 and the moving component 32 is performed at the factory, for example, without relying on the user's operation, such as when the product leaves the factory, and the standby position movement amount L3 is pre-stored.

[0203] On the other hand, Figures 17A-17C In the second initialization action described herein, the action of moving the holding member 30 and the moving member 32 to the standby position based on the standby position movement amount L3 is preferably performed each time the power of the fastening tool 1 is turned on in order to perform a stable fastening action.

[0204] Therefore, it is configured to select an initialization action related to the standby position of the holding member 30 and the moving member 32, namely a first initialization action and a second initialization action.

[0205] Figure 18 This is a flowchart illustrating an example of selecting the first initialization action and the second initialization action.

[0206] When in Figure 18 When the power is turned on in step SB1, the control unit 100 selects the initialization action to be executed in step SB2. When the control unit 100 selects to execute the first initialization action, in step SB3, the above-mentioned initialization action is executed. Figures 16A to 16D The first initialization action described herein is used to set the standby positions of the holding component 30 and the moving component 32. When the control unit 100 selects to execute the second initialization action, the above-described initialization action is executed in step SB4. Figures 17A-17C The second initialization action described herein involves moving the holding member 30 and the moving member 32 to the standby position based on the standby position movement amount L3. After executing the second initialization action, the control unit 100, in step SB5, proceeds according to the above-described... Figure 14 The flowchart, etc., is used to perform the usual fastening actions.

[0207] As described above, in the first initialization operation, the holding member 30 and the moving member 32 are moved from the front position PF to the rear position PE at a low speed, and the overall distance L1 from the front position PF to the rear position PE is obtained. The amount of movement from the rear position PE, determined in such a way that the amount of movement from the front position PF becomes a predetermined target movement amount L2, is set as the standby position movement amount L3, and recorded in a memory on a substrate (not shown) constituting the control unit 100. This eliminates various mechanical deviations such as dimensional differences within tolerance ranges, and sets the standby position of the holding member 30 and the moving member 32 to, for example, a certain position from the front position PF.

[0208] Furthermore, in the second initialization operation, whenever the user turns on the power for use, the holding member 30 and the moving member 32 are moved from the rear position PE to the standby position according to the standby position movement amount L3, thereby minimizing the movement amount of the holding member 30 and the moving member 32. Moreover, in the second initialization operation, the second initialization operation can be performed when the front end of the screwdriver bit 2 is in the standby position P1 behind the injection passage 80, and a screw 200 has been supplied to the injection passage 80.

[0209] As described above, the amount of movement (forward movement) of the screwdriver bit 2 is determined by the rotation speed of the bit movement motor 50, starting from the standby position of the holding member 30 and the moving member 32, i.e., the standby position P1 of the screwdriver bit 2. Therefore, when a deviation occurs in the standby position of the holding member 30 and the moving member 32, i.e., the standby position P1 of the screwdriver bit 2, the screwing depth set by the setting unit 110 will also be deviated.

[0210] In contrast, a second initialization action is performed each time the power is turned on. Starting from the standby position of the holding component 30 and the moving component 32, i.e. the standby position P1 of the screwdriver bit 2, the bit moving motor 50 is rotated at a speed set by the setting unit 110, so that the screw insertion depth can be accurately adjusted.

[0211] Figure 19 This is a flowchart illustrating a modified example of the operation of the fastening tool according to this embodiment. Figure 20 This is a graph showing the relationship between the output of the contact switch and the control of the bit rotation motor and the bit movement motor. Next, referring to the graphs, another example of the fastening operation of the fastening tool in this embodiment will be described. In this modified example, based on the output of the contact switch 84, it is detected whether the fastening tool 1 has lifted relative to the object being fastened, and the bit rotation motor 40 and the bit movement motor 50 are controlled.

[0212] Fastening tool 1 is in standby mode, such as Figure 1A As shown, the front end of the screwdriver bit 2 is located in the standby position P1 behind the injection passage 80, and can supply screws 200 to the injection passage 80.

[0213] Control unit 100 Figure 19In step SC1, the rotation speed of the bit movement motor 50, which determines the advance amount of the screwdriver bit 2, is set according to the setting value selected by the setting unit 110. When the contact member 81 is pressed against the object being fastened, the contact switch 84 is pushed by the contact arm 82. In step SC2, the contact switch 84 is turned on, and the trigger 9 is activated. In step SC3, when the trigger switch 90 is turned on, the control unit 100 drives the bit rotation motor 40 of the first drive unit 4 in step SC4, and drives the bit movement motor 50 of the second drive unit 5 in step SC5.

[0214] When the bit moving motor 50 is driven to rotate in the positive direction, the pulley 52 rotates in the positive direction, thereby winding the wire 54 onto the pulley 52. ​​The second moving part 32c, the moving part 32 connected to the wire 54, and the holding part 30 connected to the moving part 32 via the first moving part 32a move forward.

[0215] As a result, the screwdriver bit 2 held in the holding member 30 moves forward in the direction indicated by arrow A1, engages with the screw 200 supplied to the ejection port 81a of the head 8, and causes the screw 200 to move forward and press against the object to be fastened.

[0216] In addition, when the bit rotation motor 40 is driven to rotate in the positive direction, the holding member 30 rotates together with the rotation guide member 31.

[0217] Therefore, the screwdriver bit 2 held in the holding member 30 rotates the screw 200 in the positive direction (clockwise) and screws it into the object to be fastened. The control unit 100, in conjunction with the operation of rotating the screwdriver bit 2 by the first drive unit 4 to screw the screw into the object to be fastened, moves the screwdriver bit 2 forward by the second drive unit 5 according to the load applied to the bit rotation motor 40, the rotation speed of the bit rotation motor 40, the load applied to the bit movement motor 50, the rotation speed of the bit movement motor 50, etc., so that the screwdriver bit 2 follows the screw being screwed into the object to be fastened.

[0218] In step SC6, the control unit 100 determines that the rotation speed of the bit movement motor 50 has reached the set value selected by the setting unit 110, and the front end of the screwdriver bit 2 has reached the set end position P2. In step SC7, the control unit 100 stops driving the bit movement motor 50.

[0219] When the control unit 100 stops the drive of the bit movement motor 50 in step SC7, it determines whether the contact switch 84 is on in step SC8. When the contact switch 84 is on, the control unit 100 determines that the fastening tool 1 has not floated away from the object being fastened. In order to end the fastening operation, it stops the rotation of the bit rotation motor 40 in the forward direction in step SC9 and reverses the bit movement motor 50 in step SC10.

[0220] When the bit moving motor 50 rotates in the opposite direction, the pulley 52 rotates in the opposite direction, thereby pulling the wire 54 out from the pulley 52. ​​The second moving part 32c is pushed by the force-applying part 33, and the holding part 30 connected to the moving part 32 via the first moving part 32a moves backward.

[0221] In step SC11, when the bit moving motor 50 reverses to the initial position where the wire 54 is pulled out of the pulley 52 by a predetermined amount, and the holding member 30 and the moving member 32 move backward to the front end of the screwdriver bit 2 and return to the standby position P1, the control unit 100 stops the reverse rotation of the bit moving motor 50 in step SC12.

[0222] In step SC8, when the contact switch 84 is open, the control unit 100 determines that the fastening tool 1 is floating away from the object being fastened, and continues to drive the bit rotation motor 40 to rotate in the positive direction while stopping the drive of the bit movement motor 50.

[0223] As a result, the screwdriver bit 2 held in the holding member 30 rotates the screw 200 in the positive direction, further screwing it into the object to be fastened, thereby moving the fastening tool 1 closer to the object to be fastened. As a result, the fastening tool 1 moves relative to the contact arm 82, and the contact switch 84 is pushed by the contact arm 82, thus turning on the contact switch 84. When the contact switch 84 is not turned on, in order to end the fastening operation, the control unit 100 performs the processing of steps SC9 to SC12 described above, performing an operation to reset the screwdriver bit 2 to the standby position based on stopping the bit rotation motor 40 and reversing the bit movement motor 50.

[0224] In addition, when the contact switch 84 is disconnected and the drive of the bit moving motor 50 is stopped, the control unit 100 performs a braking operation during the operation of rotating the bit rotating motor 40 in the positive direction to prevent the bit moving motor 50 from rotating due to external force. As a result, the holding member 30, the moving member 32 and the screwdriver bit 2 held in the holding member 30 are kept in the state of stopping at the operation end position P2.

[0225] However, when the bit movement motor 50 is stopped, during the operation of rotating the bit rotation motor 40 in the forward direction, the fastening tool 1 is in a state where the operator applies force to the object being fastened while tightening the screw 200. Therefore, even if the bit movement motor 50 is braked, due to the force applied by the operator, the holding member 30, the moving member 32, and the screwdriver bit 2 held in the holding member 30 may move backward from the end position P2.

[0226] Therefore, in step SC13, the control unit 100 detects whether the bit movement motor 50 is rotating in reverse. When reverse rotation of the bit movement motor 50 is detected, the control unit returns to step SC5, causing the bit movement motor 50 to rotate forward, moving the holding member 30 and the moving member 32 forward, and returning the screwdriver bit 2 to the end position P2. Furthermore, the forward rotation of the bit movement motor 50 is stopped, and a braking action is performed.

[0227] Furthermore, in order to switch the contact switch 84 on and off via the contact arm 82, the contact arm 82 needs to move by a predetermined amount. Therefore, as described above, in step SC8, if the contact switch 84 is detected to be off, the bit movement motor 50 is stopped, but the bit rotation motor 40 continues to rotate in the forward direction until the contact switch 84 switches from off to on. During the movement of the contact arm 82, the positions of the holding member 30 and the moving member 32 may change. Therefore, it is preferable to have a detection unit that detects the position of the contact arm 82. Alternatively, a structure can be constructed in which a single motor performs the rotation of the bit holding member 3 and the axial movement of the bit holding member 3. The control unit 100 can also control the timing of stopping the drive of the single motor based on whether the contact switch 84 is activated.

[0228] Figure 21 This is a flowchart illustrating another variation of the operation of the fastening tool in this embodiment. Figure 22A , Figure 22B This is a graph showing the relationship between the load and the control of the bit rotation motor. Next, referring to the graphs, another variation of the fastening operation of the fastening tool in this embodiment will be described. In this variation, the bit rotation motor 40 is controlled by detecting the load applied to it.

[0229] Fastening tool 1 is in standby mode, such as Figure 1A As shown, the front end of the screwdriver bit 2 is located in the standby position P1 behind the injection passage 80, and can supply screws 200 to the injection passage 80.

[0230] Control unit 100 Figure 21In step SD1, the rotation speed of the bit movement motor 50, which determines the advance amount of the screwdriver bit 2, is set according to the setting value selected by the setting unit 110. When the contact member 81 is pressed against the object being fastened, the contact switch 84 is pushed by the contact arm 82. In step SD2, the contact switch 84 is turned on, and the trigger 9 is activated. In step SD3, when the trigger switch 90 is turned on, the control unit 100 drives the bit rotation motor 40 of the first drive unit 4 in step SD4, and drives the bit movement motor 50 of the second drive unit 5 in step SD5.

[0231] When the bit moving motor 50 is driven to rotate in the positive direction, the pulley 52 rotates in the positive direction, thereby winding the wire 54 onto the pulley 52. ​​The second moving part 32c, the moving part 32 connected to the wire 54, and the holding part 30 connected to the moving part 32 via the first moving part 32a move forward.

[0232] As a result, the screwdriver bit 2 held in the holding member 30 moves forward in the direction indicated by arrow A1, engages with the screw 200 supplied to the ejection port 81a of the head 8, and causes the screw 200 to move forward and press against the object to be fastened.

[0233] In addition, when the bit rotation motor 40 is driven to rotate in the positive direction, the holding member 30 rotates together with the rotation guide member 31.

[0234] Therefore, the screwdriver bit 2 held in the holding member 30 rotates the screw 200 in the positive direction (clockwise) and screws it into the object to be fastened. The control unit 100, in conjunction with the operation of rotating the screwdriver bit 2 by the first drive unit 4 to screw the screw into the object to be fastened, moves the screwdriver bit 2 forward by the second drive unit 5 according to the load applied to the bit rotation motor 40, the rotation speed of the bit rotation motor 40, the load applied to the bit movement motor 50, the rotation speed of the bit movement motor 50, etc., so that the screwdriver bit 2 follows the screw being screwed into the object to be fastened.

[0235] In step SD6, the control unit 100 determines whether the rotation speed of the bit movement motor 50 has reached the set value selected by the setting unit 110, and whether the tip of the screwdriver bit 2 has reached the set end position P2. When the control unit 100 determines that the rotation speed of the bit movement motor 50 has not reached the set value selected by the setting unit 110, in step SD7, the control unit 100 detects the load applied to the bit rotation motor 40. When a predetermined load is detected, in step SD8, the control unit 100 controls the bit rotation motor 40.

[0236] The rotational speed of the screwdriver bit 2 varies depending on the load applied to the screwdriver bit motor 40. If the current and voltage applied to the screwdriver bit motor 40 are the same, the higher the load applied to the screwdriver bit motor 40, the lower the rotational speed. Therefore, the control unit 100, as a variation detection unit that detects the main cause of the rotational speed variation of the screwdriver bit motor 40, detects the load applied to the screwdriver bit motor 40. The lower the load applied to the screwdriver bit motor 40, the lower the voltage applied to the screwdriver bit motor 40 and the lower the current flowing through the screwdriver bit motor 40, etc., compared to the case of a high load, thus reducing the output of the screwdriver bit motor 40.

[0237] Therefore, when the load applied to the bit rotating motor 40 is low, by reducing the rotational speed of the bit rotating motor 40, compared to the case of a high load, it is possible to suppress the increase in rotational speed and suppress the difference in rotational speed of the bit rotating motor 40 due to the magnitude of the load applied to it. This, in turn, can suppress deviations in the speed of the fastening screw 200.

[0238] In step SD6, the control unit 100 determines that the rotation speed of the bit movement motor 50 has reached the set value selected by the setting unit 110, and the front end of the screwdriver bit 2 has reached the set end position P2. In step SD9, the control unit 100 stops the drive of the bit rotation motor 40. After stopping the rotation of the bit movement motor 50 in the positive direction in step SD10, the control unit 100 reverses the bit movement motor 50 in step SD11.

[0239] When the bit moving motor 50 rotates in the opposite direction, the pulley 52 rotates in the opposite direction, thereby pulling the wire 54 out from the pulley 52. ​​The second moving part 32c is pushed by the force-applying part 33, and the holding part 30 connected to the moving part 32 via the first moving part 32a moves backward.

[0240] In step SD12, when the bit moving motor 50 reverses to the initial position where the wire 54 is pulled out of the pulley 52 by a predetermined amount, and the holding component 30 and the moving component 32 move backward to the position where the front end of the screwdriver bit 2 returns to the standby position P1, the control unit 100 stops the reverse rotation of the bit moving motor 50 in step SD13.

[0241] In the control that reduces the output of the bit rotation motor 40, such as Figure 22A As shown, the output can also be reduced after a predetermined load is detected, so that the rotational speed becomes constant until the screwdriver bit 2 moves to the end position of the operation by the number of revolutions of the bit rotation motor 40. Additionally, as... Figure 22BAs shown, the output can also be gradually reduced after a predetermined load is detected, so that the rotational speed of the bit rotation motor 40 before the screwdriver bit 2 moves to the end position of the operation becomes the target rotational speed.

[0242] Furthermore, due to fluctuations in the power supply voltage, the rotational speed of the screwdriver bit 2 will vary; the lower the power supply voltage, the lower the rotational speed. Therefore, the control unit 100, as a fluctuation detection unit that detects the main cause of the rotational speed variation of the bit rotational motor 40, detects the power supply voltage. The higher the power supply voltage, the more the output of the bit rotational motor 40 decreases compared to the case of a low power supply voltage.

[0243] Therefore, when the power supply voltage is high, compared to when the power supply voltage is low, by reducing the rotational speed of the bit motor 40, it is possible to suppress differences in the rotational speed of the bit motor 40 due to power supply voltage fluctuations. Thus, it is possible to suppress deviations in the speed of the fastening screw 200.

[0244] In addition, the control unit 100 can also set the target speed of the bit rotating motor 40, detect the speed of the bit rotating motor 40, compare the detected speed of the bit rotating motor 40 with the preset target speed of the bit rotating motor 40, and control the bit rotating motor 40 in a way that achieves the target speed.

[0245] Furthermore, reducing the rotational speed of the screwdriver bit motor 40 becomes a major reason for the decrease in the operating speed of tightening the screw onto the object. On the other hand, during the stopping process of the screwdriver bit motor 40 after the screw has been screwed into the target screw depth set by the setting unit 110, the screw is screwed into the object by rotating the screwdriver bit 2 until the rotation of the screwdriver bit motor 40 completely stops. Therefore, the faster the rotational speed of the screwdriver bit motor 40 is just before it stops, the deeper the screw is screwed into the target depth.

[0246] Thus, the main reason for the reduced quality of screw-in operation due to the difference in the rotation speed of the bit rotating motor 40 is the rotation speed of the bit rotating motor 40 when it is about to stop. Therefore, if the rotation speed of the bit rotating motor 40 becomes constant, excluding the influence of the load, when the movement amount (advance) of the holding component 30 and the moving component 32 is about to reach the target screw-in depth set by the setting unit 110, the desired effect can be obtained.

[0247] The load applied to the bit rotating motor 40 increases when the screw begins to be screwed into the object being fastened, but the load varies depending on the material of the object being fastened. Therefore, after detecting the load mentioned above for controlling the rotational speed of the bit rotating motor 40, the rotational speed of the bit rotating motor 40 is controlled based on the load, power supply voltage, etc., before reaching the target screw insertion depth.

[0248] Alternatively, a timing unit may be included, and the control unit 100 performs speed control of the bit rotating motor 40 based on load, power supply voltage, etc., after a predetermined time has elapsed since the start of driving (forward rotation) of the bit rotating motor 40. Additionally, a position detection unit may be included, which detects the positions of the holding member 30 and the moving member 32, and performs speed control of the bit rotating motor 40 based on load, power supply voltage, etc., after the holding member 30 and the moving member 32 reach predetermined positions. The predetermined positions of the holding member 30 and the moving member 32, which perform speed control of the bit rotating motor 40, are set between the position of the load used to control the speed of the bit rotating motor 40 and the position where the target screw insertion depth is reached.

[0249] Furthermore, in the method of setting the target speed of the bit rotary motor 40 and controlling its output, it is conceivable that due to factors such as the length of the control implementation interval, the target screw insertion depth may be reached before the speed of the bit rotary motor 40 decreases to the target speed. Therefore, braking control of the bit rotary motor 40 can also be performed during the control period for reducing the speed of the bit rotary motor 40 to the target speed. For example, braking control of the bit rotary motor 40 can be performed when the deviation between the target speed and the detected actual speed of the bit rotary motor 40 is large, until the deviation between the actual speed and the target speed is within a predetermined range. When the deviation is within the predetermined range, control is performed to reduce the speed of the bit rotary motor 40 to the target speed.

[0250] Furthermore, if the screwdriver bit 2 disengages from the screw after reaching the target screw insertion depth, the screw will not be further driven in even if the screwdriver bit 2 rotates. Therefore, the screwdriver bit movement motor 50 can be reversed after the screwdriver bit 2 has advanced to the target screw insertion depth, before the screwdriver bit rotation motor 40 stops rotating. Alternatively, a structure can be constructed in which a single motor performs the rotation of the screwdriver bit holder 3 and the axial movement of the screwdriver bit holder 3. The control unit 100 can also detect the load applied to the single motor, the main cause of the motor's speed variation, and control the motor.

[0251] Figure 23 This is a flowchart illustrating another variation of the operation of the fastening tool in this embodiment. Figure 24A This is a graph showing the relationship between the rotational speeds of the bit rotary motor and the bit movement motor in a feedback (FB) controlled system. Figure 24BThis is a graph showing the relationship between the screw's moving speed generated by the rotation of the bit rotary motor based on feedback (FB) control and the screw bit's moving speed generated by the bit movement motor. Next, another variation of the fastening operation of the fastening tool in this embodiment will be described with reference to the graphs. In this variation, the screw's moving speed generated by the rotation of the bit rotary motor 40 and the screw bit's moving speed generated by the bit movement motor 50 are synchronized by feedback control.

[0252] Fastening tool 1 is in standby mode, such as Figure 1A As shown, the front end of the screwdriver bit 2 is located in the standby position P1 behind the injection passage 80, and can supply screws 200 to the injection passage 80.

[0253] Control unit 100 Figure 23 In step SE1, the rotation speed of the bit movement motor 50, which determines the advance amount of the screwdriver bit 2, is set according to the setting value selected by the setting unit 110. When the contact member 81 is pressed against the object being fastened, the contact switch 84 is pushed by the contact arm 82. In step SE2, the contact switch 84 is turned on, and the trigger 9 is activated. In step SE3, when the trigger switch 90 is turned on, the control unit 100 drives the bit rotation motor 40 of the first drive unit 4 in step SE4, and drives the bit movement motor 50 of the second drive unit 5 in step SE5.

[0254] When the bit moving motor 50 is driven to rotate in the positive direction, the pulley 52 rotates in the positive direction, thereby winding the wire 54 onto the pulley 52. ​​The second moving part 32c, the moving part 32 connected to the wire 54, and the holding part 30 connected to the moving part 32 via the first moving part 32a move forward.

[0255] As a result, the screwdriver bit 2 held in the holding member 30 moves forward in the direction indicated by arrow A1, engages with the screw 200 supplied to the ejection port 81a of the head 8, and causes the screw 200 to move forward and press against the object to be fastened.

[0256] In addition, when the bit rotation motor 40 is driven to rotate in the positive direction, the holding member 30 rotates together with the rotation guide member 31.

[0257] Therefore, the screwdriver bit 2 held in the holding member 30 causes the screw 200 to rotate in the positive direction (clockwise) and be screwed into the object to be fastened. The control unit 100, in conjunction with the action of rotating the screwdriver bit 2 through the first drive unit 4 to screw the screw into the object to be fastened, moves the screwdriver bit 2 forward through the second drive unit 5, so that the screwdriver bit 2 follows the screw being screwed into the object to be fastened.

[0258] In step SE6, the control unit 100 determines whether the rotation speed of the bit movement motor 50 has reached the set value selected by the setting unit 110, and whether the tip of the screwdriver bit 2 has reached the set end position P2. If the control unit 100 determines that the rotation speed of the bit movement motor 50 has not reached the set value selected by the setting unit 110, then in step SE7, it detects the load applied to the bit movement motor 50. When a predetermined load is detected, in step SE8, it obtains the rotation speed of the bit rotation motor 40 and the rotation speed of the bit movement motor 50.

[0259] In step SE9, the control unit 100 calculates the rotational speeds of the bit rotating motor 40 and the bit moving motor 50 based on the rotational speeds of the bit rotating motor 40 and the bit moving motor 50, the gear ratio of the reducer, etc., so that the screw 200 is fastened to the object by the rotation of the bit rotating motor 40, thereby determining the forward speed of the screw 200, the forward movement speed of the holding member 30 and the moving member 32 by the rotation of the bit moving motor 50, and the forward movement speed of the screw bit 2 mounted on the holding member 30. Figure 24B It is roughly the same as shown.

[0260] In step SE10, the control unit 100 controls the bit moving motor 50 in this example through feedback control based on the rotational speed of the bit rotary motor 40, the rotational speed of the bit moving motor 50, the gear ratio of the reducer, etc. For example, the speed is adjusted by increasing or decreasing the PWM output to the bit moving motor 50.

[0261] In step SE6, the control unit 100 determines that the rotation speed of the bit movement motor 50 has reached the set value selected by the setting unit 110. When the front end of the screwdriver bit 2 reaches the set end position P2, the control unit 100 stops the drive of the bit rotation motor 40 in step SE11. After stopping the rotation of the bit movement motor 50 in the positive direction in step SE12, the control unit 100 reverses the bit movement motor 50 in step SE13.

[0262] When the bit moving motor 50 rotates in the opposite direction, the pulley 52 rotates in the opposite direction, thereby pulling the wire 54 out from the pulley 52. ​​The second moving part 32c is pushed by the force-applying part 33, and the holding part 30 connected to the moving part 32 via the first moving part 32a moves backward.

[0263] In step SE14, if the bit moving motor 50 reverses to the initial position where the wire 54 is pulled out of the pulley 52 by a predetermined amount, and the holding component 30 and the moving component 32 move backward to the front end of the screwdriver bit 2 and return to the standby position P1, then in step SE15, the reverse rotation of the bit moving motor 50 is stopped.

[0264] Furthermore, the aforementioned feedback control is required after the load on the bit rotation motor 40 and bit movement motor 50 changes due to contact between the fastening object and the screw 200. Therefore, the control without feedback control is set as the first control mode, and the control with feedback control is set as the second control mode. The first control mode is executed before a predetermined load is detected in either or both of the bit rotation motor 40 or bit movement motor 50. When a predetermined load is detected in either or both of the bit rotation motor 40 or bit movement motor 50, the first control mode is switched to the second control mode, and the second control mode is executed. This suppresses delays in operation time.

[0265] Furthermore, as a means to improve the responsiveness of feedback control and achieve more stable work quality, the acceleration / deceleration limit value of the bit movement motor 50 can be changed when feedback control is executed after load detection and when feedback control is not executed before load detection. Normally, when the motor is outputting PWM, control is performed to limit the acceleration per unit time, especially to prevent excessive acceleration current during startup, in order to stabilize the motor output. However, if the above-mentioned feedback control is executed while the bit movement motor 50 is under acceleration limitation during startup, the PWM output generated in the feedback control is limited and applied to the bit movement motor 50, thus worsening the responsiveness to feedback control. Therefore, when executing feedback control, it is preferable to set the acceleration limit value to be larger than that during motor startup when feedback control is not executed.

[0266] Figure 25 This is a flowchart illustrating another variation of the operation of the fastening tool in this embodiment. Figure 26A , Figure 26B This is a graph showing the relationship between the load and the control of the bit movement motor. Next, referring to the graphs, another variation of the fastening operation of the fastening tool in this embodiment will be described. In this variation, the bit movement motor 50 is controlled by detecting the load applied to it.

[0267] Fastening tool 1 is in standby mode, such as Figure 1A As shown, the front end of the screwdriver bit 2 is located in the standby position P1 behind the injection passage 80, and can supply screws 200 to the injection passage 80.

[0268] Control unit 100 Figure 25In step SF1, the rotation speed of the bit movement motor 50, which determines the advance amount of the screwdriver bit 2, is set according to the setting value selected by the setting unit 110. When the contact member 81 is pressed against the object being fastened, the contact switch 84 is pushed by the contact arm 82. In step SF2, the contact switch 84 is turned on, and the trigger 9 is activated. In step SF3, when the trigger switch 90 is turned on, the control unit 100 drives the bit rotation motor 40 of the first drive unit 4 in step SF4, and drives the bit movement motor 50 of the second drive unit 5 in step SF5.

[0269] When the bit moving motor 50 is driven to rotate in the positive direction, the pulley 52 rotates in the positive direction, thereby winding the wire 54 onto the pulley 52. ​​The second moving part 32c, the moving part 32 connected to the wire 54, and the holding part 30 connected to the moving part 32 via the first moving part 32a move forward.

[0270] As a result, the screwdriver bit 2 held in the holding part 30 moves forward in the direction indicated by arrow A1, engages with the screw 200 supplied to the injection port 81a of the head 8, and causes the screw 200 to move forward and press against the object to be fastened.

[0271] In addition, when the bit rotation motor 40 is driven to rotate in the positive direction, the holding member 30 rotates together with the rotation guide member 31.

[0272] Therefore, the screwdriver bit 2 held in the holding member 30 causes the screw 200 to rotate in the positive direction (clockwise) and be screwed into the object to be fastened. The control unit 100, in conjunction with the action of rotating the screwdriver bit 2 through the first drive unit 4 to screw the screw into the object to be fastened, moves the screwdriver bit 2 forward through the second drive unit 5, so that the screwdriver bit 2 follows the screw being screwed into the object to be fastened.

[0273] In step SF6, the control unit 100 determines whether the rotation speed of the bit movement motor 50 has reached the set value selected by the setting unit 110, and whether the tip of the screwdriver bit 2 has reached the set end position P2. If the control unit 100 determines that the rotation speed of the bit movement motor 50 has not reached the set value selected by the setting unit 110, in step SF7, the control unit 100 detects the load applied to the bit movement motor 50. When a predetermined load is detected, the control unit 100 controls the bit movement motor 50 in step SF8.

[0274] Since the bit rotation motor 40 operates at its maximum output within a conceived range, in order to suppress the forward movement of the holding member 30 and the moving member 32 by the drive of the bit movement motor 50, thereby reducing the tightening speed by generating excessive impact when the screw 200 is pressed against the object being tightened, the bit rotation motor 40 operates at its maximum output within a conceived range, and the output of the bit movement motor 50 is limited by reducing the voltage applied to the bit movement motor 50 and reducing the current flowing through the bit movement motor 50.

[0275] When the ratio of the advance of the screwdriver bit 2 per revolution of the bit movement motor 50 to the advance of the screw per revolution of the bit rotation motor 40 decreases, the advance of the screwdriver bit 2 based on the bit movement motor 50 cannot keep up with the advance of the screw based on the bit rotation motor 40, thus causing it to come loose. On the other hand, when the ratio of the advance of the screwdriver bit 2 per revolution of the bit movement motor 50 to the advance of the screw per revolution of the bit rotation motor 40 increases, the advance of the screwdriver bit 2 based on the bit movement motor 50 greatly exceeds the advance of the screw based on the bit rotation motor 40, thus requiring excessive force for the operator to press the fastening tool 1 towards the object being fastened.

[0276] Therefore, as a target value for output limitation, the preferred ratio of the advance of the screwdriver bit 2 per revolution of the bit movement motor 50 to the advance of the screw per revolution of the bit rotation motor 40 is approximately 0.8 to 5 times. This suppresses the occurrence of dislodgement, and requires less force from the operator when pressing the fastening tool 1 towards the object being fastened. Excessive impact is also suppressed when the screw 200 is pressed against the object being fastened.

[0277] In addition, when the load on the bit movement motor 50 generated after the fastening object comes into contact with the screw 200 is detected, the output of the bit movement motor 50 is limited, thereby slowing down the holding member 30 and the moving member 32 when the screw 200 is pressed against the fastening object, thereby achieving a further effect of suppressing impact.

[0278] In the control of limiting the output of the bit movement motor 50, such as Figure 26A As shown, the output can also be limited so that after a predetermined load is detected, the bit moving motor 50 maintains a constant speed until the bit rotating motor 40 rotates the screwdriver bit 2 to the end position of the operation. Additionally, as... Figure 26BAs shown, before a predetermined load is detected, the bit movement motor 50 is rotated forward at a first speed. After the predetermined load is detected, in order to reduce the impact when the screw 200 is pressed against the fastening object, the bit movement motor 50 is rotated forward at a second speed with a reduced speed. Furthermore, the output can be limited so that after a predetermined buffer time during which the impact when the screw 200 is pressed against the fastening object weakens, a third speed, slower than the first speed but faster than the second speed, is used until the number of revolutions the bit rotation motor 40 makes to rotate the screwdriver bit 2 to the end position of the operation, becomes a constant speed.

[0279] Furthermore, due to fluctuations in the power supply voltage, the moving speed (forward speed) of the holding component 30 and the moving component 32 differs. The higher the power supply voltage, the faster the moving speed, which can easily cause excessive impact when the screw 200 is pressed against the object being fastened. Therefore, the control unit 100 detects the power supply voltage, and the higher the power supply voltage, the lower the output of the bit moving motor 50 is compared to the case of a low power supply voltage.

[0280] Therefore, variations in the rotational speed of the bit movement motor 50 caused by fluctuations in the power supply voltage can be suppressed. Consequently, when the screw 200 is pressed against the object being fastened, excessive impact can be suppressed, and deviations in the speed at which the screw 200 is pressed against the object being fastened can be prevented.

[0281] In step SF6, the control unit 100 determines that the rotation speed of the bit movement motor 50 has reached the set value selected by the setting unit 110, and when the front end of the screwdriver bit 2 reaches the set end position P2, the control unit 100 stops the drive of the bit rotation motor 40 in step SF9, and after stopping the rotation of the bit movement motor 50 in the positive direction in step SF10, the control unit 100 reverses the bit movement motor 50 in step SF11.

[0282] When the bit moving motor 50 rotates in the opposite direction, the pulley 52 rotates in the opposite direction, thereby pulling the wire 54 out from the pulley 52. ​​The second moving part 32c is pushed by the force-applying part 33, and the holding part 30 connected to the moving part 32 via the first moving part 32a moves backward.

[0283] In step SF12, when the bit moving motor 50 reverses to the initial position where the wire 54 is pulled out of the pulley 52 by a predetermined amount, and the holding member 30 and the moving member 32 move backward to the front end of the screwdriver bit 2 and return to the standby position P1, the control unit 100 stops the reverse rotation of the bit moving motor 50 in step SF13.

[0284] Figure 27This is a flowchart illustrating another variation of the operation of the fastening tool according to this embodiment. Next, another variation of the fastening operation of the fastening tool according to this embodiment will be described with reference to the figures. In this variation, the load applied to the bit movement motor 50, etc., is detected to suppress drive in the absence of screws.

[0285] Fastening tool 1 is in standby mode, such as Figure 1A As shown, the front end of the screwdriver bit 2 is located in the standby position P1 behind the injection passage 80, and can supply screws 200 to the injection passage 80.

[0286] Control unit 100 Figure 27 In step SG1, the rotation speed of the bit movement motor 50, which determines the advance amount of the screwdriver bit 2, is set according to the setting value selected by the setting unit 110. When the contact member 81 is pressed against the object being fastened, the contact switch 84 is pushed by the contact arm 82. In step SG2, the contact switch 84 is turned on, and the trigger 9 is operated. In step SG3, when the trigger switch 90 is turned on, the control unit 100 drives the bit rotation motor 40 of the first drive unit 4 in step SG4, and drives the bit movement motor 50 of the second drive unit 5 in step SG5.

[0287] When the bit moving motor 50 is driven to rotate in the positive direction, the pulley 52 rotates in the positive direction, thereby winding the wire 54 onto the pulley 52. ​​The second moving part 32c, the moving part 32 connected to the wire 54, and the holding part 30 connected to the moving part 32 via the first moving part 32a move forward.

[0288] As a result, the screwdriver bit 2 held in the holding part 30 moves forward in the direction indicated by arrow A1, engages with the screw 200 supplied to the injection port 81a of the head 8, and causes the screw 200 to move forward and press against the object to be fastened.

[0289] In addition, when the bit rotation motor 40 is driven to rotate in the positive direction, the holding member 30 rotates together with the rotation guide member 31.

[0290] Therefore, the screwdriver bit 2 held in the holding member 30 causes the screw 200 to rotate in the positive direction (clockwise) and be screwed into the object to be fastened. The control unit 100, in conjunction with the action of rotating the screwdriver bit 2 through the first drive unit 4 to screw the screw into the object to be fastened, moves the screwdriver bit 2 forward through the second drive unit 5, so that the screwdriver bit 2 follows the screw being screwed into the object to be fastened.

[0291] In step SG6, the control unit 100 determines whether the rotational speed of the bit movement motor 50 has reached the set value selected by the setting unit 110, and whether the tip of the screwdriver bit 2 has reached the set end position P2. If the control unit 100 determines that the rotational speed of the bit movement motor 50 has not reached the set value selected by the setting unit 110, in step SG7, the control unit 100 detects the load applied to either or both of the bit rotation motor 40 and the bit movement motor 50. If a predetermined load is detected by pressing the screw 200 against the object being fastened, the bit movement motor 50 continues to rotate in the positive direction until the rotational speed of the bit movement motor 50 reaches the set value selected by the setting unit 110.

[0292] When the control unit 100 determines in step SG6 that the rotation speed of the bit movement motor 50 has reached the set value selected by the setting unit 110 and the front end of the screwdriver bit 2 has reached the set end position P2, it stops the drive of the bit rotation motor 40 in step SG8, ​​and stops the rotation of the bit movement motor 50 in the positive direction in step SG9, and then reverses the bit movement motor 50 in step SG10.

[0293] When the bit moving motor 50 rotates in the opposite direction, the pulley 52 rotates in the opposite direction, thereby pulling the wire 54 out from the pulley 52. ​​The second moving part 32c is pushed by the force-applying part 33, and the holding part 30 connected to the moving part 32 via the first moving part 32a moves backward.

[0294] In step SG11, when the bit moving motor 50 reverses to the initial position where the wire 54 is pulled out of the pulley 52 by a predetermined amount, and the holding member 30 and the moving member 32 move backward to the front end of the screwdriver bit 2 and return to the standby position P1, the control unit 100 stops the reverse rotation of the bit moving motor 50 in step SG12.

[0295] When there is no screw 200 at the injection port 81a, when the bit rotation motor 40 and bit movement motor 50 rotate in the positive direction, the screw 200 will not be pressed against the object being fastened, and therefore the load applied to the bit rotation motor 40 and bit movement motor 50 will not increase. Therefore, if even if the screwdriver bit 2 mounted on the holding member 30 advances by a predetermined amount of movement based on the length of the minimum screw 200 being loaded, no predetermined load is detected, it can be determined that there is no screw 200.

[0296] Therefore, in step SG13, the control unit 100 determines whether the bit movement motor 50 has rotated by a predetermined amount of movement based on the length of the smallest screw 200 loaded, and whether the screwdriver bit 2 mounted on the holding member 30 has advanced by a predetermined amount of idle motion detection. Furthermore, if the control unit 100 determines that a predetermined load is not detected in either the bit rotation motor 40 or the bit movement motor 50, and determines that the bit movement motor 50 has rotated by the predetermined amount of idle motion detection, it determines that there is no screw 200, and issues an error notification in step SG14. Additionally, in the processing of steps SG8 to SG12 described above, the driving of the bit rotation motor 40 and the bit movement motor 50 is stopped.

[0297] The control unit 100 can also detect the load applied to either or both of the bit rotation motor 40 or the bit movement motor 50 based on changes in the current flowing through the motor, in addition to changes in the current generated when the motor starts. Alternatively, it can detect changes in the voltage flowing through the motor, in addition to changes in the voltage generated when the motor starts. Furthermore, it can be a structure where a single motor performs the rotation of the bit holder 3 and the axial movement of the bit holder 3, and the control unit 100 can also detect the load applied to the single motor to suppress drive in the absence of screws.

[0298] Next, another variation of the fastening operation of the fastening tool according to this embodiment will be described. Here, to prevent malfunction, the fastening tool 1 starts the screw fastening operation when both the contact arm 82, which is engaged based on the pressing of the contact member 81 against the object being fastened, and the trigger switch 90, which is engaged based on the pulling operation of the trigger 9, are met. The contact arm 82 is structured such that there is a stroke from disconnection to being determined to be engaged. In order to reliably detect the engagement of the contact arm 82, a margin is left for further pressing from the engaged state, taking into account assembly deviations of the fastening tool. As a result, within the stroke of the contact arm 82, even in the same disconnection or the same engagement, there may be a situation where the positions of the contact member 81 and the contact arm 82 change. In this case, for example, depending on the pressing position of the contact member 81, the screw fastening operation is sometimes performed with the contact member 81 slightly floating relative to the tool body 10, thereby causing the seat of the screw head to float from the surface of the object being fastened, resulting in poor driving in. Therefore, in this modified example, a technique is provided to eliminate the variation in the connection and disconnection positions of the contact arm 82 caused by assembly deviations of the fastening tool 1, thereby improving the accuracy of the connection and disconnection of the contact arm 82.

[0299] Figure 28This is a side view showing an example of the fastening tool involved in the modified example. In addition, in the fastening tool 1A of the modified example, the same reference numerals are used for structures that are common to the fastening tool 1 of the above embodiment, and repeated descriptions of structures and operations that are common to the above embodiment are omitted or simplified by referring to the description of the fastening tool 1.

[0300] like Figure 28 As shown, the fastening tool 1A includes: a first drive unit 4 for rotating a screwdriver bit 2 held by a bit holder 3; and a second drive unit 5 for moving the screwdriver bit 2 held by the bit holder 3 axially. Additionally, the fastening tool 1A includes: a screw storage unit 6 for storing screws 200 (see reference). Figure 1A The tool body 10; the handle 11 is mounted on the lower surface of the tool body 10; and the battery 12 is mounted on the lower end of the handle 11 in a detachable manner.

[0301] The head 8 includes: an injection passage 80; an injection outlet 81a; a contact member 81 that contacts the object to be fastened; a contact arm 82 that moves in a forward and backward direction in conjunction with the contact member 81; and a magnet 82a that moves in conjunction with the contact arm 82.

[0302] The contact member 81 is supported in a manner that allows it to move in the forward and backward directions as indicated by arrows A1 and A2. The contact arm 82 moves in the forward and backward directions in conjunction with the movement of the contact member 81. The contact member 81 of the machine head 8 is subjected to a force in the forward direction by a force-applying member (not shown). The contact member 81, which is pressed against the fastening object and moves backward, is subjected to a force in the forward direction by the force-applying member.

[0303] The fastening tool 1A has a magnet 82a at the rear end of the contact arm 82, facing the magnetic element 130. The magnet 82a moves in conjunction with the contact arm 82 in the front-rear direction indicated by arrows A1 and A2. For example, the magnet 82a can be a structure that is installed as a separate component at the rear end of the contact arm 82, or it can be integrally formed at the rear end of the contact arm 82. In this embodiment, the rear end of the contact arm 82 is branched into two strands, but as a non-separable structure, the magnet 82a is also installed at this location.

[0304] A magnetic element 130 is disposed on the side of the tool body 10 on one side of the contact arm 82 and faces the magnet 82a of the contact arm 82. The magnetic element 130 detects an analog magnetic field generated by the magnet 82a of the contact arm 82. The contact arm 82 moves toward the magnetic element 130 by a pressing action of the contact member 81 toward a target object. The magnitude of the magnetic field detected by the magnetic element 130 varies depending on the distance between the magnet 82a of the contact arm and the magnetic element 130. Therefore, the position of the contact arm 82 relative to the magnetic element 130 can be detected by detecting the magnetic force of the magnet 82a.

[0305] Figure 29 This is a block diagram illustrating an example of the fastening tool 1A according to this embodiment. Figure 29 As shown, in addition to the bit rotation motor 40, bit movement motor 50, trigger switch 90, and setting unit 110, the control unit 100 is also connected to a magnetic element 130 and a recording unit 150.

[0306] The magnetic element 130 detects the magnetic field generated by the magnet 82a and outputs a voltage proportional to the magnitude of the detected magnetic field to the control unit 100. The magnet 82a is disposed on the contact arm 82, which is pressed toward the rear side of the tool body 10 in conjunction with the pressing action of the contact member 81 toward the object to be fastened.

[0307] The control unit 100 acquires the voltage value based on the magnetic field of the magnet 82a output by the magnetic element 130. The control unit 100 has a threshold setting mode that calculates a threshold for determining whether the contact arm 82 is on or off, using the acquired voltage value based on the magnetic field of the magnet 82a to determine whether the contact arm 82 is on. The threshold setting mode can be selected via a setting unit 110 provided on the tool body 10, or via an operation unit separately provided on the tool body 10. Alternatively, the threshold setting mode can be selected and executed via wired or wireless communication from an information processing device such as a personal computer or tablet computer.

[0308] Furthermore, during actual screw-in operations, the control unit 100 acquires the voltage of the magnetic field generated by the magnet 82a of the contact arm 82, which moves toward the rear of the tool body 10 in conjunction with the pressing action of the contact member 81 toward the object being tightened. Based on a comparison between the acquired voltage value and a threshold calculated in the threshold setting mode, the control unit 100 determines whether the contact arm 82 is on or off. That is, depending on the on or off state of the contact arm 82, the control unit determines whether to activate the bit rotation motor 40 to begin screw tightening, set it to a non-action (no screw tightening), or end screw tightening.

[0309] The recording unit 150 records various data, such as thresholds calculated in the threshold setting mode executed by the control unit 100. The recording unit 150 can be, for example, a magnetic storage device such as a hard disk drive (HDD), a semiconductor storage device, an optical storage device, or a photoelectric storage device.

[0310] Next, we will explain an example of the operation when the fastening tool 1A is in the execution threshold setting mode. Figure 30 This is a flowchart illustrating an example of the operation when the fastening tool 1A executes the threshold setting mode. The following description will illustrate, for example, the case where the threshold setting mode is executed before the fastening tool 1A leaves the factory. The threshold setting mode is implemented for each fastening tool.

[0311] like Figure 30 As shown, in step SH1, in the fastening tool 1A, the contact member 81 is pressed to a maximum pressed position, which is an example of a reference position, within the range that allows it to be pressed against the object being fastened. In this modified example, the maximum pressed position refers to the position where the rear surface of the contact member 81 abuts against the front surface of the tool body 10. Alternatively, the reference position can be anything other than the maximum pressed position of the contact member 81, for example, it can be any position within the range (stroke) of the contact member 81's pressable movement. Furthermore, the reference position can be multiple positions for staged pressing, or any position selected from multiple positions. After the contact member 81 is pressed against the object being fastened, step SH2 is performed.

[0312] In step SH2, the magnetic element 130 detects the magnetic field generated by the magnet 82a, which has moved towards the rear of the tool body 10 along with the contact arm 82, and outputs a voltage proportional to the magnetic field to the control unit 100. Because of assembly deviations in each fastening tool, the position (distance) of the magnet 82a relative to the magnetic element 130 varies in each fastening tool, resulting in different voltage values ​​output from the magnetic element 130 of each fastening tool. The control unit 100 acquires the voltage value output from the magnetic element 130. After acquiring the voltage value, it proceeds to step SH3.

[0313] In step SH3, the control unit 100 calculates a threshold value based on the acquired voltage value to determine whether the contact arm 82 is on or off. For example, the control unit 100 sets the position of the contact arm 82 when the contact member 81 is pressed to the rear of the tool body 10 to the maximum extent as the reference position O, and sets the position in front of the reference position O as the "+ side" as the position in front of the reference position O. The voltage value at a position α (slightly in front of the position where the contact arm 82 is pressed to the maximum extent) that is +αmm ahead of the reference position O is used as the threshold value. The threshold value may have a certain width. After calculating the threshold value, the process proceeds to step SH4.

[0314] In step SH4, the control unit 100 records the calculated threshold in the recording unit 150. In this modified example, a threshold setting mode is implemented for each fastening tool, taking into account assembly deviations or tolerances of each component. As a result, a threshold for determining the connection of the contact arm 82 is calculated for each fastening tool, and the calculated threshold is stored in the recording unit 150 of each fastening tool.

[0315] Next, use in Figure 30 The threshold for determining the activation of contact arm 82, calculated and recorded, is used to illustrate an example of the operation during screw-in using fastening tool 1B. Furthermore, the basic operation in this case is similar to... Figure 19 The actions shown are common, therefore, in this variation, the descriptions of common actions are omitted or simplified.

[0316] Figure 31 This is a flowchart illustrating a modified example of the operation of the fastening tool according to this embodiment. Figure 32 It is a graph showing the relationship between the position of the contact arm and the control of the bit rotation motor and bit movement motor.

[0317] When fastening tool 1B is in standby mode, such as Figure 1A As shown, the front end of the screwdriver bit 2 is located in the standby position P1 behind the injection passage 80, and can supply screws 200 to the injection passage 80.

[0318] Control unit 100 Figure 31 In step SI1, the rotation speed of the screwdriver bit movement motor 50, which determines the forward movement of the screwdriver bit 2, is set according to the setting value selected by the setting unit 110.

[0319] When the operator presses the contact member 81 against the object being fastened, the contact arm 82 and the magnet 82a disposed on the contact arm 82 move toward the rear of the tool body 10 in a coordinated manner. In step SI2, the magnetic element 130 detects the magnetic field of the magnet 82a disposed on the contact arm 82 moving toward the rear of the tool body 10, and outputs a voltage proportional to the magnitude of the detected magnetic field. The control unit 100 compares the voltage value based on the magnetic field of the magnet 82a output from the magnetic element 130 with a threshold value pre-calculated in a threshold setting mode. If the voltage value is above the threshold value, it determines that the contact arm 82 is on. On the other hand, if the voltage value is below the threshold value, it determines that the contact arm 82 is off. For example, as described above, when the voltage value at position α + α mm from the reference position O is set as the threshold value, when the contact arm 82 is pressed in further than position α + α mm, the obtained voltage value is above the pre-set threshold value, so it can be determined that the contact arm 82 is on.

[0320] In step SI3, when the contact arm 82 is closed and the trigger switch 90 is closed by the operation of the trigger 9, the control unit 100 proceeds to step SI4. In step SI4, the control unit 100 drives the bit rotation motor 40 of the first drive unit 4, and in step SI5, it drives the bit movement motor 50 of the second drive unit 5.

[0321] When the bit movement motor 50 is driven to rotate in the positive direction, the pulley 52 rotates in the positive direction, thereby winding the wire 54 onto the pulley 52. ​​The second moving part 32c, the moving part 32 connected to the wire 54, and the holding part 30 connected to the moving part 32 via the first moving part 32a move forward. As a result, the screwdriver bit 2 held in the holding part 30 moves forward in the direction indicated by arrow A1, engages with the screw 200 supplied to the ejection port 81a of the head 8, and causes the screw 200 to move forward, pressing it against the object to be fastened.

[0322] Furthermore, when the screwdriver bit rotation motor 40 is driven to rotate in the positive direction, the holding member 30 and the rotation guide member 31 rotate together. As a result, the screwdriver bit 2, held in the holding member 30, causes the screw 200 to rotate in the positive direction (clockwise) and be screwed into the object being fastened. The control unit 100, in conjunction with the operation of rotating the screwdriver bit 2 via the first drive unit 4 to screw the screw into the object, moves the screwdriver bit 2 forward via the second drive unit 5 according to the load applied to the screwdriver bit rotation motor 40, the rotation speed of the screwdriver bit rotation motor 40, the load applied to the screwdriver bit movement motor 50, and the rotation speed of the screwdriver bit movement motor 50, thereby causing the screwdriver bit 2 to follow the screw being screwed into the object.

[0323] In step SI6, the control unit 100 determines that the rotation speed of the bit movement motor 50 has reached the set value selected by the setting unit 110, and when the front end of the screwdriver bit 2 reaches the set end position P2, the control unit 100 stops driving the bit movement motor 50 in step SI7.

[0324] When the control unit 100 stops driving the bit movement motor 50 in step SI7, it determines whether the contact arm 82 is engaged in step SI8. Specifically, the control unit 100 determines whether the contact arm 82 is engaged based on whether the voltage value of the magnetic field based on the magnet 82a is above a preset threshold. When the contact arm 82 is engaged, the control unit 100 determines that the contact member 81 of the fastening tool 1A has not floated away from the object being fastened. In order to end the fastening operation, it stops the bit rotation motor 40 from rotating in the forward direction in step SI9 and reverses the bit movement motor 50 in step SI10.

[0325] When the bit moving motor 50 rotates in the opposite direction, the pulley 52 rotates in the opposite direction, thereby pulling the wire 54 out from the pulley 52. ​​The second moving part 32c is pushed by the force-applying part 33, and the holding part 30 connected to the moving part 32 via the first moving part 32a moves backward.

[0326] In step SI11, when the bit moving motor 50 reverses to the initial position where the wire 54 is pulled out of the pulley 52 by a predetermined amount, and the holding member 30 and the moving member 32 move backward to the front end of the screwdriver bit 2 and return to the standby position P1, the control unit 100 stops the reverse rotation of the bit moving motor 50 in step SI12.

[0327] In step SI8, if the contact arm 82 is disconnected, the control unit 100 determines that the contact member 81 of the fastening tool 1A is floating away from the object being fastened, and continues to drive the bit rotation motor 40 to rotate in the positive direction while the bit movement motor 50 is stopped.

[0328] As a result, the screwdriver bit 2 held in the holding member 30 rotates the screw 200 in the positive direction, further screwing it into the object to be fastened, thereby moving the fastening tool 1A closer to the object to be fastened. Simultaneously, the fastening tool 1A moves relative to the contact arm 82, and the control unit 100 determines that the contact arm 82 is engaged. When the contact arm 82 is engaged, in order to end the fastening operation, the control unit 100 performs the processing described above in steps SI9 to SI12, stopping the bit rotation motor 40 and resetting the screwdriver bit 2 to its standby position based on the reverse rotation of the bit movement motor 50.

[0329] In addition, when the voltage value of the magnetic field based on the magnet 82a is less than a preset threshold, the control unit 100 determines that the contact arm 82 is disconnected. While the bit moving motor 50 is stopped, during the operation of rotating the bit rotating motor 40 in the positive direction, a braking operation is performed to prevent the bit moving motor 50 from rotating due to external force. As a result, the holding member 30, the moving member 32, and the screwdriver bit 2 held in the holding member 30 are kept in the stopped state at the operation end position P2.

[0330] However, even when the bit movement motor 50 is stopped, during the operation of rotating the bit rotation motor 40 in the forward direction, the screw 200 is tightened while the operator applies force in the direction that presses the fastening tool 1A against the object being fastened. Therefore, even if the bit movement motor 50 is braked, the retaining member 30, the moving member 32, and the screwdriver bit 2 held in the retaining member 30 may still move backward from the end position P2 due to the force applied by the operator.

[0331] Therefore, in step SI13, the control unit 100 detects whether the bit movement motor 50 is reversing, such as... Figure 32 As indicated by the arrow, when reverse rotation of the bit movement motor 50 is detected, the process returns to step SI5, causing the bit movement motor 50 to rotate forward. This moves the holding component 30 and the moving component 32 forward, returning the screwdriver bit 2 to the end position P2. Then, the forward rotation of the bit movement motor 50 is stopped, and a braking action is performed.

[0332] Furthermore, while the above embodiment described an example of performing a threshold setting mode before the fastening tool 1A leaves the factory, it is not a limitation. For example, the threshold setting mode can also be performed after the fastening tool 1A leaves the factory. This is because after the fastening tool 1A leaves the factory, the assembly state of the tool may change, or the shape of the contact parts 81, contact arms 82, etc., may change due to years of deterioration caused by the use of the tool. In such cases, the positions where the contact parts 81 and contact arms 82 are set to be in contact may differ. Therefore, after using the fastening tool 1A for a certain period of time, the user can also perform a threshold setting mode to recalculate and reset the threshold for when the contact arm 82 is in contact.

[0333] Next, a modified example of the magnetic element 130, which is an example of the position detection unit described above, will be described. In the above embodiment, the magnetic element 130 is used as the position detection unit for detecting the position of the contact arm 82, which moves in conjunction with the pressing action of the contact member 81. However, a distance sensor 140 may be used instead of the magnetic element 130. When the position detection unit is composed of a distance sensor 140, it is not necessary to provide a magnet 82a at the end of the contact arm 82.

[0334] Figure 33 This is a block diagram illustrating an example of the fastening tool 1B according to this embodiment. Figure 33 As shown, in addition to the bit rotation motor 40, bit movement motor 50, trigger switch 90, setting unit 110, and recording unit 150, the control unit 100 is also connected to a distance sensor 140.

[0335] The distance sensor 140, in conjunction with the pressing action of the contact member 81 against the object being fastened, measures an analog distance, i.e., the distance, between itself and the rear end of the contact arm 82 pressed into the rear side of the tool body 10, and outputs the measured distance information to the control unit 100. The distance measured by the distance sensor 140 corresponds to the position of the contact arm 82 relative to the distance sensor 140; therefore, by measuring the distance of the contact arm 82, the position information of the contact member 81 and the contact arm 82 can be detected.

[0336] The control unit 100 acquires distance information based on the position of the rear end of the contact arm 82, output by the distance sensor 140. The control unit 100 includes a threshold setting mode that calculates a threshold for determining whether the contact arm 82 is on or off, and calculates a threshold for determining whether the contact arm 82 is on using the acquired distance information. Furthermore, during actual screw-in operations, the control unit 100 acquires the distance between the contact arm 82, which moves in conjunction with the contact member 81 towards the rear of the tool body 10, and determines whether the contact arm 82 is on based on a comparison between the acquired distance information and the threshold calculated in the threshold setting mode.

[0337] In addition, it is possible to use Figure 30 , Figure 31 The flowchart illustrating the fastening tool 1A with the magnetic element 130 shown is applied to the processing of the distance sensor 140 using this modified example. That is, by replacing the magnetic element 130 with the distance sensor 140 and replacing the voltage value with distance information, it is possible to achieve [the desired result] even when using the distance sensor 140. Figure 30 The threshold setting mode shown Figure 31 The action shown is the screw-in operation.

[0338] Next, as an example of the aforementioned position detection unit, namely the magnetic element 130, it can also be composed of a pressure detection unit. This pressure detection unit detects the pressure of the contact arm 82, which moves toward the rear of the tool body 10 in conjunction with the pressing action of the contact member 81. In this case, for example, the pressure of the contact arm 82 when the contact member 81 is pressed in to its maximum extent can be preset as a threshold. During actual screw tightening, the pressure detected by the pressure detection unit through the pressing of the contact arm 82 is compared with the threshold. If the pressure is above the threshold, it is determined that the contact arm 82 is engaged.

[0339] As described above, according to this modified example, the position of the contact arm 82 when the contact member 81 is pressed into its maximum position is used as a reference, and a threshold is set based on the magnitude of the magnetic field of the magnet 82a mounted on the contact arm 82. Therefore, the accuracy of the contact arm 82's on / off position is improved, and the on / off position of the contact arm 82 can be adjusted to always be the same, unaffected by component size or assembly deviations. The on / off position of the contact arm 82 can be set for each fastening tool. Thus, even in cases where there are assembly deviations in the fastening tools 1A and 1B, variations in the on / off position of the contact arm 82 and the lifting of the contact member 81 can be eliminated, providing fastening tools 1A and 1B with high precision for screw tightening operations.

[0340] Furthermore, although preferred embodiments of the present disclosure have been described in detail with reference to the accompanying drawings, the technical scope of the present disclosure is not limited thereto. For example, in the above embodiments, an example of contact member 81 and contact arm 82 being composed of different components has been described, but it is not limited thereto; contact member 81 and contact arm 82 may also be composed of a single component.

[0341] Explanation of reference numerals in the attached figures

[0342] 1. 1A, 1B... Fastening tools; 10... Tool body; 10a... Housing; 10b... Front frame; 10c... Rear frame; 10d... Connecting parts; 10e... Screws; 10f... Head body; 11... Handle; 12... Battery; 13... Battery mounting part; 2... Screwdriver bits; 3... Bit holder; 30... Holding parts; 30a... Opening; 30b... ··Connecting component, 31···Rotation guide component, 31a···Gutter, 32···Moving component, 32a···First moving component, 32b···Bearing (bearing), 32c···Second moving component, 33···Force application component, 34a···Bearing (bearing), 4···First drive unit, 40···Bit rotary motor (motor, first motor), 40a···Shaft, 41···Reducer, 41a···Shaft, 4 2. Bearing; 5. Second drive unit; 50. Bit moving motor (motor, second motor); 50a. Shaft; 51. Reducer; 51a. Shaft; 52. Pulley (transmission component); 53. Bearing; 54. Wire (transmission component); 6. Screw storage unit; 7. Screw feed unit; 70. Screw feed motor; 71. Pinion; 72. Rack; 73. Engaging part, 8...head unit, 80...ejection passage, 81...contact component, 81a...ejection outlet, 82...contact arm, 82a...magnet, 83...adjustment part, 84...contact switch part, 9...trigger, 90...trigger switch part, 100...control part, 110...setting part, 130...magnetic element (position detection part), 140...distance sensor (position detection part).

Claims

1. A fastening tool, comprising: The screwdriver bit holder holds the screwdriver bit in a detachable manner and is rotatable in the circumferential direction and movable in the axial direction of the screwdriver bit; A motor rotates the bit holder and moves the bit holder axially. Contact component, which comes into contact with the object being fastened; and The control unit controls the timing of stopping the motor drive based on the axial movement of the contact member when it contacts the object being fastened. The contacting component contacts the object being fastened and is axially movable, wherein the screw engaged with the screwdriver bit is fastened to the object being fastened. The fastening tool also includes a contact switch, which switches on and off based on the axial movement of the contact component. The control unit controls the timing of stopping the motor drive based on whether the contact switch is turned on or off. When the bit holder moves axially to the end position, the control unit determines whether the contact switch is on or off. When the contact switch is off, the control unit causes the motor's fastening screw to continue rotating in one direction.

2. A fastening tool, comprising: The screwdriver bit holder holds the screwdriver bit in a detachable manner and is rotatable in the circumferential direction and movable in the axial direction of the screwdriver bit; A motor rotates the bit holder and moves the bit holder axially. Contact component, which comes into contact with the object being fastened; and The control unit controls the timing of stopping the motor drive based on the axial movement of the contact member when it contacts the object being fastened. The contacting component contacts the object being fastened and is axially movable, wherein the screw engaged with the screwdriver bit is fastened to the object being fastened. The fastening tool also includes a contact switch, which switches on and off based on the axial movement of the contact component. The control unit controls the timing of stopping the motor drive based on whether the contact switch is turned on or off. The motor has the following features: The first motor rotates the bit holding part; and The second motor causes the bit holder to move axially. The control unit controls the axial position of the bit holder by controlling the rotation speed of the second motor. When the control unit rotates the second motor a number of revolutions that move the bit holding part to the end position of the operation, it determines whether the contact switch is turned on or off. When the contact switch is off, it causes the first motor to continue rotating in one direction.

3. The fastening tool according to claim 2, wherein, After the control unit rotates the first motor in one direction toward the fastening screw and the second motor in one direction toward the direction that moves the bit holding part toward the object being fastened, it controls the timing of stopping the drive of the first motor and the second motor according to the rotation speed of the second motor and the on or off state of the contact switch.

4. A fastening tool, comprising: The screwdriver bit holder holds the screwdriver bit in a detachable manner and is rotatable in the circumferential direction and movable in the axial direction of the screwdriver bit; A motor rotates the bit holder and moves the bit holder axially. Contact component, which comes into contact with the object being fastened; and The control unit controls the timing of stopping the motor drive based on the axial movement of the contact member when it contacts the object being fastened. The contact component contacts the object being fastened and is movable in the axial direction. The fastening tool includes: The contact arm is movable in the axial direction in conjunction with the contact component; and The position detection unit detects the position of the contact arm. The control unit determines whether the contact arm is on or off based on the position of the contact arm detected by the position detection unit, and drives the motor when both the trigger and the contact arm are on, and controls the timing of stopping the motor drive based on the on or off state of the contact arm.

5. The fastening tool according to claim 4, wherein, The control unit determines whether the contact arm is connected or disconnected based on a comparison between the position of the contact arm detected by the position detection unit and a threshold set according to the reference position of the contact arm.

6. The fastening tool according to claim 5, wherein, The reference position is the position of the contact arm when the contact member is pressed into the fastening object to the maximum extent.

7. The fastening tool according to any one of claims 4 to 6, wherein, The fastening tool includes a magnet that moves in conjunction with the contact arm. The position detection unit is composed of a magnetic element that detects the magnetic field generated by the magnet, and outputs a voltage proportional to the magnitude of the magnetic field detected by the magnetic element as the position information of the contact arm to the control unit. The control unit determines whether the contact arm is connected or disconnected based on the comparison result between the voltage and a preset threshold.

8. The fastening tool according to any one of claims 4 to 6, wherein, The position detection unit is composed of a distance sensor, which measures the distance between the position detection unit and the contact arm, and outputs this distance as the position information of the contact arm to the control unit. The control unit determines whether the contact arm is connected or disconnected based on a comparison between the distance and a preset threshold.

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