Fastening tool

Abstract

The present application provides a fastening tool capable of controlling movement of a screwdriver bit toward a direction of approaching a fastening object according to the presence or absence of a screw. The fastening tool includes a bit holding portion holding a screwdriver bit in a detachable manner and capable of rotating in a circumferential direction of the screwdriver bit and moving in an axial direction; a bit rotating motor rotating the bit holding portion; a bit moving motor moving the bit holding portion in the axial direction; and a control portion controlling a position of the bit holding portion in the axial direction by a rotation amount of the bit moving motor, the control portion judging the presence or absence of the screw according to one or both of a load applied to the bit rotating motor rotating the bit holding portion in one direction toward a fastening screw and a load applied to the bit moving motor rotating the bit holding portion in one direction toward a direction of approaching the fastening object, and stopping rotation of the bit rotating motor and the bit moving motor when the screw is judged to be absent.

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 movable tool called a nail-driving machine is known that uses the air pressure of compressed air supplied from an air compressor and the combustion pressure of a gas to sequentially drive out connecting stops loaded in a nail box 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, a pneumatic 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 is 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 documents

[0007] Patent Document 1: Japanese Patent No. 5262461

[0008] Patent Document 2: Japanese Patent No. 6197547 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] Even without a screw, the screwdriver bit will move toward the object being fastened, whether it is a screwdriver that uses air pressure or a screwdriver that uses spring force to drive in a screw, and there is a possibility that the screwdriver bit will collide with the object being fastened.

[0011] This invention was made to solve such a problem, and its purpose is to provide a fastening tool that can control the movement of the screwdriver bit toward the object being fastened based on the presence or absence of a screw.

[0012] Technical solutions for solving the problem

[0013] 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 in the circumferential direction and moving in the axial direction of the screwdriver bit; a motor for rotating the bit holder and moving the bit holder axially; and a control unit for controlling the axial position of the bit holder by the amount of rotation of the motor, wherein the control unit stops the rotation of the motor based on a load applied to the motor rotating in a direction that moves the bit holder toward the object being fastened.

[0014] In this invention, when it is determined that there is no screw based on the load applied to the motor, the rotation of the motor stops, and the forward movement of the screwdriver bit mounted on the bit holder is inhibited.

[0015] Invention Effects

[0016] In this invention, the movement of the screwdriver bit toward the object being fastened can be controlled based on the presence or absence of a screw. Attached Figure Description

[0017] Figure 1A This is a side sectional view showing an example of the internal structure of the fastening tool of this embodiment.

[0018] Figure 1B This is a top sectional view showing an example of the internal structure of the fastening tool of this embodiment.

[0019] Figure 1C This is a front sectional view showing an example of the internal structure of the fastening tool of this embodiment.

[0020] Figure 2A This is an exploded perspective view showing an example of the internal structure of the fastening tool according to this embodiment.

[0021] Figure 2B This is a perspective view showing an example of the fastening tool of this embodiment.

[0022] Figure 3A This is a perspective view showing an example of the main structure of the fastening tool according to this embodiment.

[0023] Figure 3B This is a perspective view showing an example of the main structure of the fastening tool according to this embodiment.

[0024] 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.

[0025] Figure 4B This is a cross-sectional perspective view showing an example of the main structural components of the fastening tool according to this embodiment.

[0026] 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.

[0027] Figure 5 This is a top sectional view showing an example of the main structural components of the fastening tool according to this embodiment.

[0028] Figure 6A This is a top sectional view showing an example of the internal structure of the fastening tool of this embodiment.

[0029] Figure 6B This is a top sectional view showing an example of the internal structure of the fastening tool of this embodiment.

[0030] Figure 7A This is a cross-sectional view showing an example of a disassembly and assembly retention mechanism.

[0031] Figure 7B This is a cross-sectional view showing an example of a disassembly and assembly retention mechanism.

[0032] Figure 8A This is a perspective view showing an example of a disassembly and assembly retention mechanism.

[0033] Figure 8B This is a perspective view showing an example of a disassembly and assembly retention mechanism.

[0034] Figure 9 This is a perspective view showing an example of the screw feed section and the machine head of this embodiment.

[0035] Figure 10A This is a perspective view taken from the rear, showing an example of the fastening tool of this embodiment.

[0036] Figure 10B This is a perspective view taken from the rear, showing an example of the fastening tool of this embodiment.

[0037] Figure 10C This is a perspective view taken from the rear, showing an example of the fastening tool of this embodiment.

[0038] Figure 11 This is a three-dimensional diagram representing an example of a design department.

[0039] Figure 12 This is a block diagram illustrating an example of the fastening tool of this embodiment.

[0040] Figure 13A This is a side sectional view illustrating an example of the operation of the fastening tool in this embodiment.

[0041] Figure 13B This is a top sectional view showing an example of the operation of the fastening tool in this embodiment.

[0042] Figure 14 This is a flowchart illustrating an example of the operation of the fastening tool in this embodiment.

[0043] Figure 15A This is a cross-sectional view showing the tightened state of the screw.

[0044] Figure 15B This is a cross-sectional view showing the tightened state of the screw.

[0045] Figure 15C This is a cross-sectional view showing the tightened state of the screw.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] Figure 18 This is a flowchart illustrating an example of selecting the first initialization action and the second initialization action.

[0054] Figure 19 This is a flowchart illustrating a variation of the operation of the fastening tool in this embodiment.

[0055] Figure 20 It 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.

[0056] Figure 21This is a flowchart illustrating other variations of the operation of the fastening tool in this embodiment.

[0057] Figure 22A It is a graph showing the relationship between load and the control of the bit rotation motor.

[0058] Figure 22B It is a graph showing the relationship between load and the control of the bit rotation motor.

[0059] Figure 23 This is a flowchart illustrating other variations of the operation of the fastening tool in this embodiment.

[0060] Figure 24A It is a graph showing the relationship between the rotational speeds of the bit rotary motor and the bit moving motor based on feedback control.

[0061] 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.

[0062] Figure 25 This is a flowchart illustrating other variations of the operation of the fastening tool in this embodiment.

[0063] Figure 26A It is a graph showing the relationship between the load and the control of the bit movement motor.

[0064] Figure 26B It is a graph showing the relationship between the load and the control of the bit movement motor.

[0065] Figure 27 This is a flowchart illustrating other variations of the operation of the fastening tool in this embodiment. Detailed Implementation

[0066] Hereinafter, embodiments of the fastening tool of the present invention will be described with reference to the accompanying drawings.

[0067] <Example of the structure of the fastening tool in this embodiment>

[0068] 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.

[0069] The fastening tool 1 of this embodiment includes: a bit holding part 3 for holding a screwdriver bit 2 so that it can rotate and move axially; 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.

[0070] 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.

[0071] 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 detachably mounting the battery 12.

[0072] 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.

[0073] 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.

[0074] In the screw storage section 6, multiple screws 200 are connected by a connecting band, storing the connecting screws wound in a spiral shape.

[0075] 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.

[0076] 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, so that it can be detached and installed; a rotation guide member 31, which supports the holding member 30 so that it can 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 rear direction as indicated by arrow A2.

[0077] The outer diameter of the retaining member 30 is slightly smaller than the inner diameter of the rotary guide member 31, and it is constructed from a cylindrical component that 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.

[0078] 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 axial direction 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.

[0079] The rotary guide member 31 has two radially opposite sides with grooves 31a 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.

[0080] 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.

[0081] The long side of the elongated oval shape of the connecting member 30b is in the direction of the extension of the groove 31a, which is parallel to the axial direction of the screwdriver bit 2 indicated by arrows A1 and A2. The short side of the elongated oval shape is in the direction orthogonal to the extension of the groove 31a, indicated by arrows B1 and B2, that is, in the direction of rotation of the rotating guide member 31. Furthermore, the width of the short side of the elongated oval shape of the connecting member 30b, that is, the width along the direction of rotation of the rotating guide member 31, is configured to be slightly smaller than the width of the groove 31a along that direction.

[0082] 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 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.

[0083] 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.

[0084] 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.

[0085] The inner diameter of the first moving member 32a is slightly larger than the outer diameter of the rotary guide member 31, and it is constructed of, for example, a cylindrical member that enters 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, and is thus supported to be movable along the axial direction of the rotary guide member 31.

[0086] 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 it from moving in the rotational direction and axial direction, and the outer ring is supported on the inner periphery of the second moving member 32c in a manner that prevents it from moving in the rotational direction and axial direction.

[0087] Thus, the second moving member 32c is connected to the first moving member 32a via the bearing 32b while its movement in the forward and backward direction along the axial direction is restricted. Furthermore, the second moving member 32c supports the first moving member 32a via the bearing 32b, enabling it to rotate.

[0088] 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.

[0089] 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.

[0090] The first drive unit 4 includes a bit rotation motor 40 and a reducer 41, both electrically driven by a battery 12. The bit rotation motor 40 is an example of a motor or a first motor. The shaft 40a of the bit rotation 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 uses a planetary gear structure for the reducer 41. 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 are arranged coaxially.

[0091] 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 supported on the rear frame 10c via a bearing 42. Thus, the rotation guide member 31 is rotatably supported via a bearing 42, which is an example of a bearing.

[0092] 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 through 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.

[0093] Furthermore, the front end of the rotating guide member 31 of the bit holder 3 is supported by a bearing 34a on a front frame 10b fixed to the front of the housing 10a of the tool body 10, and the rear end of the rotating guide member 31 is supported by a shaft 41a of the reducer 41 and a bearing 42 on a rear frame 10c fixed to the rear of the housing 10a. Therefore, the rotating guide member 31 of the bit holder 3 is rotatably supported on the tool body 10.

[0094] 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.

[0095] 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 are opposite to the circumferential surface of the guide member 32g.

[0096] Thus, guided by the connecting member 10d via the guide member 32g, 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.

[0097] 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, detailing the second drive unit 5. Next, the second drive unit 5 will be described with reference to the figures.

[0098] 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.

[0099] 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. ​​As the pulley 52 rotates, the wire 54 is wound onto the pulley 52. ​​In addition, the other end of the wire 54 is connected to the wire connection portion 32h of the second moving member 32c provided on the moving member 32.

[0100] Therefore, the second drive unit 5 rotates the pulley 52 via the bit movement motor 50, winding 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, and the holding member 30, which is connected to the first moving member 32a via the connecting member 30b, moves forward, causing the screwdriver bit 2 held by the holding member 30 to move in the forward direction indicated by arrow A1.

[0101] The second drive unit 5 is positioned offset to one side from approximately the center in the left-right direction of the fastening tool 1, with the tangential direction of the portion on the pulley 52 where the wire 54 is wound along the extending direction of the rotation guide member 31. That is, the center of the pulley 52, in this example, is the shaft 50a of the bit movement motor 50, offset to one side relative to the rotation guide member 31, and when viewed from the axial direction of the pulley 52, the portion 52a on the pulley 52 where the wire 54 is wound overlaps with the rotation guide member 31.

[0102] 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.

[0103] Furthermore, when the wire 54 is wound 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. Additionally, 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.

[0104] Therefore, the diameter of pulley 52 is set so that the rotation amount α of pulley 52 required for the screwdriver bit 2 to move a predetermined amount is less than 360°.

[0105] 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 will not overlap and wrap around the pulley 52, 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.

[0106] Therefore, the rotation amount of the bit moving motor 50 and the movement amount of the holding member 30 are in a one-to-one relationship throughout the entire movable range of the holding member 30. By controlling the rotation amount of the bit moving motor 50, the movement amount of the holding member 30 along the axial direction of the rotation guide member 31 can be controlled. That is, by controlling the rotation amount of the bit moving motor 50, the movement amount of the screwdriver bit 2 mounted on the holding member 30 can be controlled.

[0107] 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 rotation 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 via the screwdriver bit 2.

[0108] As a result, 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 suppresses the increase in load when the wire 54 is wound by the pulley 52 and the increase in load when the wire 54 is pulled out from the pulley 52.

[0109] Furthermore, since 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, by means of 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.

[0110] 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.

[0111] Therefore, by arranging the bit rotation motor 40, the rotation guide member 31, and 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 rotates without moving the bit rotation motor 40 in the front-back direction and moves the screwdriver bit 2 in the front-back direction.

[0112] Furthermore, in a structure in which the bit rotation motor 40 and the screwdriver bit 2 are arranged coaxially, it is possible to use a feed screw to convert the rotational motion of the bit rotation motor 40 into the forward and backward movement of the screwdriver bit 2.

[0113] However, in the structure that uses a feed screw, the forward movement of the screwdriver bit 2 per revolution of the motor cannot be large. Therefore, even if the rotational speed of the motor is increased, it is difficult to speed up the movement of the screwdriver bit 2.

[0114] 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.

[0115] In contrast, in a structure where the retaining member 30 holding the screwdriver bit 2 is supported in a manner that allows it to move in the front-rear direction relative to the rotation guide member 31, and the retaining member 30 moves forward by rotating the pulley 52 via the second drive unit 5 to wind the wire 54, the moving speed of the screwdriver bit 2 can be increased according to the rotational speed of the bit moving motor 50. Therefore, the time required to press the screw 200 onto the object to be fastened using the screwdriver bit 2 can be shortened.

[0116] 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 described with reference to the figures.

[0117] 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.

[0118] When the insertion part 20 of 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.

[0119] When the insertion portion 20 of the screwdriver bit 2 is inserted into the opening 30a of the retaining member 30 until the groove 20a formed on the outer periphery of the insertion portion 20 is positioned opposite the ball 30d, the ball 30d, which is stressed by the spring 30e, is engaged in the groove 20a. This prevents the screwdriver bit 2 from being accidentally pulled out of the retaining member 30.

[0120] 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.

[0121] 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 at the outer periphery of the retaining member 30. On the other hand, when the retaining member 30 is inserted into the interior of 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.

[0122] Furthermore, in order 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, if the diameter difference between the retaining member 30 and the rotating guide member 31 is set, 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. As a result, the device becomes larger.

[0123] In contrast, the rotary guide member 31 is provided with a groove 31a for the guide connecting member 30b. The groove 31a extends through 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.

[0124] Therefore, in the disassembly and assembly retaining mechanism 30c, the ball 30d is positioned in tandem with 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.

[0125] 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.

[0126] Therefore, by maintaining the structure of the component 30 inserted into the interior of the cylindrical rotary guide component 31, space can be ensured for the ball 30d of the disassembly and assembly retaining mechanism 30c to retract. In addition, by using the groove 31a into which the connecting component 30b enters as a space for the ball 30d to retract, the area of ​​the opening provided in the rotary guide component 31 can be suppressed, thus ensuring strength.

[0127] Furthermore, by ensuring 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 without increasing the diameter difference between the retaining member 30 and the rotating guide member 31, the enlargement of the device can be suppressed.

[0128] 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 figures.

[0129] 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 engaging with a connecting screw fed from the screw storage unit 6.

[0130] The rack 72 of the screw feed unit 7 is movably supported in the vertical direction along the feed direction of the connecting screw. The screw feed unit 7 is fed by the screw feed motor 70 rotating forward and backward, and the engaging part 73 that engages with the connecting screw moves in the vertical direction.

[0131] 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.

[0132] 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.

[0133] At the machine head 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 conjunction with the contact member 81 in the front-back direction. At the machine head 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 is pushed backward by the fastened object, is also subjected to a force in the forward direction by the force-applying member.

[0134] At 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 active and inactive states by being pushed by the contact arm 82. In this example, the state where the contact switch unit 84 is inactive when not pushed by the contact arm 82 is defined as the open state of the contact switch unit 84, and the state where the contact switch unit 84 is activated when pushed by the contact arm 82 is defined as the closed state of the contact switch unit 84.

[0135] Next, referring to the figures, the structure related to the control and operation of the fastening tool 1 will be described. The fastening tool 1 includes a trigger 9 that receives operation and a trigger switch 90 that is actuated by 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 actuated by being pushed by the trigger 9.

[0136] The trigger switch 90 switches between active and inactive states by being pushed by the trigger 9. In this example, the state in which the trigger 9 is not operated, the trigger switch 90 is not pushed by the trigger 9 and the trigger switch 90 is inactive is defined as the trigger switch 90 being off, and the state in which the trigger 9 is operated, the trigger switch 90 is pushed by the trigger 9 and is inactive is defined as the trigger switch 90 being on.

[0137] 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 is operated by the trigger 9, and the contact switch unit 84, which is pushed by the contact member 81.

[0138] 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.

[0139] 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.

[0140] 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.

[0141] 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 substrate 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.

[0142] In contrast, by providing a substrate storage portion 111 on the back side of the screw storage portion 6, it is possible to suppress the enlargement of the fastening tool 1 in the vertical direction along the extension direction of the handle 11. Furthermore, since the screw storage portion 6 houses the connecting screw wound into 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.

[0143] 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 described with reference to the figures.

[0144] 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.

[0145] Therefore, by controlling the rotation amount of the bit movement motor 50, the movement amount (forward amount) of the screwdriver bit 2 can be controlled. That is, by rotating the bit movement motor 50 in conjunction with the rotation of the bit rotation motor 40 that rotates the screwdriver bit 2 in the direction of tightening the screw 200, the forward amount of the screwdriver bit 2 that follows the screw 200 as it is tightened can be controlled by the rotation amount of the bit movement motor 50, thereby controlling the axial stop position of the screwdriver bit 2.

[0146] 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.

[0147] 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. Furthermore, the setting unit 110 may also be structured so that the selected setting value is displayed by means of a label, engraving, or other means, or by means of a display unit 110b such as an LED, so that the operator can easily grasp the current setting value.

[0148] 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 opposite to the handle 11.

[0149] 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.

[0150] When using the screwdriver by holding the handle 11, the side of the screw storage section 6 opposite to the handle 11 faces the operator holding the fastening tool 1. Therefore, in the base plate storage section 111 located on the back side of the screw storage section 6, the display section 110b provided on the side opposite to the handle 11 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 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 a screw, the remaining screw weight, and the presence or absence of any abnormalities.

[0151] Furthermore, when using the handle 11 by hand, the buttons and other operating parts 110a located on the setting unit 110 are easily visible. Therefore, while holding the handle 11 with one hand, one can visually confirm the operating parts 110a and operate them with the other hand, enabling reliable operation.

[0152] 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 opposite to the handle 11, the substrate for the setting section 110 can be omitted, unlike the control unit 100.

[0153] 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 along the rotation guide member 31 in a forward direction along the axial direction of the screwdriver bit 2.

[0154] Therefore, by controlling the rotation of the bit movement motor 50, the control unit 100 can control the movement (advance) of the screwdriver bit 2. That is, in conjunction with the rotation of the bit rotation motor 40 that rotates the screwdriver bit 2 in the direction of tightening the screw 200, by rotating the bit movement motor 50, the advance of the screwdriver bit 2, which follows the screw 200 as it is tightened, can be controlled by the rotation of the bit movement motor 50, thereby controlling the axial stop position of the screwdriver bit 2.

[0155] Furthermore, the control unit 100 sets the rotation amount of the bit movement motor 50, which is predetermined for the forward movement of the screwdriver bit 2, by the setting unit 110. Moreover, the control unit 100 controls the presence or absence of the drive of the bit movement motor 50 of the second drive unit 5 and the bit rotation motor 40 of the first drive unit 4 based on the combination of the on / off state of the contact switch unit 84 and the on / off state of the trigger switch unit 90.

[0156] <Example of the operation of the fastening tool in this embodiment>

[0157] 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 14The flowchart shows 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.

[0158] 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.

[0159] Control unit 100 Figure 14 In step SA1, the rotation amount of the bit movement motor 50, which determines the forward advance 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, and 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 control unit 100 drives the bit rotation motor 40 of the first drive unit 4 in step SA4, and drives the bit movement motor 50 of the second drive unit 5 in step SA5.

[0160] 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. ​​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 while moving forward in the axial direction.

[0161] 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.

[0162] 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 and press against the object to be fastened.

[0163] 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.

[0164] 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 is linked to the operation of rotating the screwdriver bit 2 by the first drive unit 4 to screw the screw into the object to be fastened. 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., the second drive unit 5 moves the screwdriver bit 2 forward, so that the screwdriver bit 2 follows the screw that is screwed into the object to be fastened.

[0165] In step SA6, the control unit 100 determines that the rotation amount 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.

[0166] 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. ​​By pulling the wire 54 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.

[0167] 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.

[0168] 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, thereby the holding part 30 moves in the rearward direction along the axial direction of the screwdriver bit 2.

[0169] In step SA10, if 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 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, then in step SA11, the reverse rotation of the bit moving motor 50 is stopped.

[0170] 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 supplying the next screw 200 to the injection passage 80.

[0171] 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 the state in which the head 201 of the screw 200 is embedded in the object 202 being fastened.

[0172] When the fastening tool 1 reaches the end position P2 at the front end of the screwdriver bit 2, if the screw 200 is a countersunk screw, as follows: 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. 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, and the head 201 of the screw 200 does not float up from the object being fastened 202.

[0173] When the front end 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 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 as shown, the setting unit 110 sets the movement amount (forward amount) of the screwdriver bit 2. By reducing the number of revolutions (rotation amount) 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.

[0174] As described above, the amount of movement (forward movement) of the screwdriver bit 2 is determined by the number of revolutions (rotation) 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 by the amount of rotation 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.

[0175] 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 amount 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.

[0176] Then, before the driving and tightening actions begin, the holding member 30 and the moving member 32 are moved to the set standby position. Using the standby position as a reference, the position of the holding member 30 and the moving member 32 is controlled by the rotation of the bit movement motor 50. Then, the holding member 30 and the moving member 32 are advanced from the set standby position to a predetermined movement amount (advance amount) 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.

[0177] As a unit for setting the standby position of the holding member 30 and the moving member 32 in the first initialization operation, a unit using a sensor is considered, and the unit is 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 the position moved by a predetermined amount from the detection position is set as the standby position.

[0178] 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.

[0179] 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.

[0180] like Figure 16AAs shown, the control unit 100 starts from a state where the holding member 30 and the moving member 32 are in arbitrary positions, and causes the bit moving motor 50 to rotate 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 rotation guide member 31 in the axial direction along the screwdriver bit 2.

[0181] like Figure 16B As shown, when the bit moving motor 50 rotates forward until the holding member 30 and the moving member 32 move to the front end position PF, which is one of the end positions, 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.

[0182] 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.

[0183] like Figure 16C As shown, when the bit moving motor 50 reverses until the holding member 30 and the moving member 32 move to the rear end position PE, which is the end position of the other, 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.

[0184] 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 from the rotation amount of the bit moving motor 50.

[0185] The control unit 100 presets the movement amount of the holding member 30 and the moving member 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 member 30 and the moving member 32 from the rear position PE.

[0186] 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 (rotation amount) 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.

[0187] 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 at a low speed that does not affect the durability of the tool.

[0188] 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 a preset standby position will be explained.

[0189] 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.

[0190] like Figure 17B As shown, when the bit moving motor 50 reverses until 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.

[0191] 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 (rotation amount) 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.

[0192] exist Figures 16A to 16DIn the first initialization action described herein, 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 is shipped, and the standby position movement amount L3 is pre-stored.

[0193] 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.

[0194] 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.

[0195] Figure 18 This is a flowchart illustrating an example of selecting the first initialization action and the second initialization action.

[0196] When in Figure 18 In step SB1, when the power is turned on, 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 sets 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.

[0197] 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.

[0198] 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 the screw 200 is supplied to the injection passage 80.

[0199] As described above, the amount of movement (forward movement) of the screwdriver bit 2 is determined by the rotation speed (rotation amount) 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 there is a deviation 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.

[0200] In contrast, a second initialization action is performed each time the power is turned on. Starting from the standby position of component 30 and moving component 32, i.e. the standby position P1 of screwdriver bit 2, the screwdriver bit moving motor 50 is rotated by the amount of rotation set by the setting unit 110, thereby enabling accurate adjustment of the screw insertion depth.

[0201] 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, other examples 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.

[0202] 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.

[0203] Control unit 100 Figure 19In step SC1, the rotation amount of the 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. When the contact member 81 is pressed by 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.

[0204] 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.

[0205] 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 and press against the object to be fastened.

[0206] 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.

[0207] 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 is linked to the operation of rotating the screwdriver bit 2 by the first drive unit 4 to screw the screw into the object to be fastened. 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., the second drive unit 5 moves the screwdriver bit 2 forward, so that the screwdriver bit 2 follows the screw that is screwed into the object to be fastened.

[0208] When the control unit 100 determines in step SC6 that the rotation amount 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 operation end position P2, the control unit 100 stops the drive of the bit movement motor 50 in step SC7.

[0209] 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 turned on in step SC8. When the contact switch 84 is turned 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 positive direction in step SC9, and reverses the bit movement motor 50 in step SC10.

[0210] 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. ​​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 in the rearward direction.

[0211] In step SC11, if 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 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, then in step SC12, the reverse rotation of the bit moving motor 50 is stopped.

[0212] In step SC8, if the contact switch 84 is disconnected, 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.

[0213] 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. Therefore, the fastening tool 1 moves relative to the contact arm 82, and the contact switch 84 is pushed by the contact arm 82, activating the contact switch 84. When the contact switch 84 is activated, the control unit 100 performs the above-described steps SC9 to SC12 to end the fastening operation, resetting the screwdriver bit 2 to the standby position by stopping the bit rotation motor 40 and reversing the bit movement motor 50.

[0214] 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.

[0215] However, 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 tightening tool 1 is being pressed against the object being tightened by the operator. 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.

[0216] 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. Then, the forward rotation of the bit movement motor 50 is stopped, and a braking action is performed.

[0217] 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, when 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 positive 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 rotates the bit holding member 3 and moves the bit holding member 3 axially. 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.

[0218] Figure 21 This is a flowchart illustrating other variations of the operation of the fastening tool according to 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, other variations of the fastening operation of the fastening tool in this embodiment will be described. In this variation, the load applied to the bit rotation motor 40 is detected, and the bit rotation motor 40 is controlled.

[0219] 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.

[0220] Control unit 100 Figure 21In step SD1, the rotation amount 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.

[0221] 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.

[0222] As a result, the screwdriver bit 2 held in the holding part 30 moves forward in the direction indicated by arrow A1 and engages with the screw 200 supplied to the ejection port 81a of the head 8, causing the screw 200 to move forward and press against the object to be fastened.

[0223] 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.

[0224] 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 is linked to the operation of rotating the screwdriver bit 2 by the first drive unit 4 to screw the screw into the object to be fastened. 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., the second drive unit 5 moves the screwdriver bit 2 forward, so that the screwdriver bit 2 follows the screw that is screwed into the object to be fastened.

[0225] In step SD6, the control unit 100 determines whether the rotation amount 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 amount 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.

[0226] The rotational speed of the screwdriver bit 2 varies depending on the load applied to the screwdriver bit rotary motor 40. If the current and voltage values ​​applied to the screwdriver bit rotary motor 40 are the same, the higher the load applied to the screwdriver bit rotary motor 40, the lower the rotational speed. Therefore, the control unit 100, as a variation detection unit that detects the main cause of the variation in the rotational speed of the screwdriver bit rotary motor 40, detects the load applied to the screwdriver bit rotary motor 40. The lower the load applied to the screwdriver bit rotary motor 40, the lower the voltage value applied to the screwdriver bit rotary motor 40 and the lower the current value flowing through the screwdriver bit rotary motor 40, etc., compared to the case of a high load, thereby reducing the output of the screwdriver bit rotary motor 40.

[0227] 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. Thus, it is possible to suppress deviations in the speed of the fastening screw 200.

[0228] In step SD6, the control unit 100 determines that the rotation amount 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.

[0229] 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. ​​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 in the rearward direction.

[0230] In step SD12, if 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 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, then the control unit 100 stops the reverse rotation of the bit moving motor 50 in step SD13.

[0231] 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 amount of rotation 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 rotary motor 40 before the screwdriver bit 2 moves to the end position of the operation becomes the target rotational speed.

[0232] Furthermore, due to fluctuations in the power supply voltage, the rotational speed of the screwdriver bit 2 varies; 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 fluctuations in the rotational speed of the screwdriver bit rotary motor 40, detects the power supply voltage. The higher the power supply voltage, the more the output of the screwdriver bit rotary motor 40 decreases compared to the case of a low power supply voltage.

[0233] 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 rotating motor 40, it is possible to suppress the difference in rotational speed of the bit rotating motor 40 caused by power supply voltage fluctuations. Thus, deviations in the speed of the fastening screw 200 can be suppressed.

[0234] In addition, the control unit 100 can also set the target rotation speed of the bit rotary motor 40, detect the rotation speed of the bit rotary motor 40, compare the detected rotation speed of the bit rotary motor 40 with the preset target rotation speed of the bit rotary motor 40, and control the bit rotary motor 40 in a way that achieves the target rotation speed.

[0235] Furthermore, reducing the rotation 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 penetration 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 rotation speed of the screwdriver bit motor 40 is just before it stops, the deeper the screw is screwed into the target depth.

[0236] Thus, the main reason for the reduced quality of screw-in operation due to the difference in rotational speed of the bit rotary motor 40 is the rotational speed of the bit rotary motor 40 when it is about to stop. Therefore, if the rotational speed of the bit rotary motor 40 becomes constant, excluding the influence of 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.

[0237] 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 rotation speed of the bit rotating motor 40, the rotation speed of the bit rotating motor 40 is controlled based on the load, power supply voltage, etc., before reaching the target screw insertion depth.

[0238] Furthermore, a timing unit may be included, and the control unit 100 performs control of the rotation speed of the bit 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 motor 40. Additionally, a position detection unit may be included to detect the positions of the holding member 30 and the moving member 32, and perform control of the rotation speed of the bit 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 the control of the rotation speed of the bit motor 40, are set between the position where the load used to control the rotation speed of the bit motor 40 is detected and the position where the target screw insertion depth is reached.

[0239] Furthermore, in the method of setting the target rotational speed of the bit rotary motor 40 and controlling its output, considering the influence of factors such as the length of the control implementation interval, the target screw insertion depth may be reached before the rotational speed of the bit rotary motor 40 decreases to the target rotational speed. Therefore, braking control of the bit rotary motor 40 can also be performed during the control period of reducing the rotational speed of the bit rotary motor 40 to the target rotational speed. For example, braking control of the bit rotary motor 40 can be performed when the deviation between the target rotational speed and the detected actual rotational speed of the bit rotary motor 40 is large, until the deviation between the actual rotational speed and the target rotational speed is within a specified range. When the deviation is within the specified range, control is performed to reduce the rotational speed of the bit rotary motor 40 to the target rotational speed.

[0240] 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 bit movement motor 50 can be reversed after the screwdriver bit 2 has advanced to the target screw insertion depth, before the bit rotation motor 40 stops rotating. Alternatively, a single motor can be used to rotate the bit holder 3 and move it axially. The control unit 100 can also detect the load applied to the single motor, the main cause of changes in the motor's rotation speed, and control the motor.

[0241] Figure 23This is a flowchart illustrating other variations of the operation of the fastening tool according to 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 24B This 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 screwdriver bit's moving speed generated by the bit moving motor. Next, referring to the graphs, other variations of the fastening operation of the fastening tool in this embodiment will be described. In this variation, the screw's moving speed generated by the rotation of the bit rotary motor 40 and the screwdriver bit's moving speed generated by the bit moving motor 50 are synchronized by feedback control.

[0242] 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.

[0243] Control unit 100 Figure 23 In step SE1, the rotation amount of the 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. 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.

[0244] 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.

[0245] 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.

[0246] 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.

[0247] 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 that is screwed into the object to be fastened.

[0248] In step SE6, the control unit 100 determines whether the rotation amount 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 amount 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 number of the bit rotation motor 40 and the rotation number of the bit movement motor 50.

[0249] 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 speed at which the screw 200 moves forward by being fastened to the object by the rotation of the bit rotating motor 40 is compared with the speed of the retaining member 30 and the moving member 32 moving forward by the rotation of the bit moving motor 50, as well as the speed of the screw bit 2 mounted on the retaining member 30. Figure 24B It is roughly the same as shown.

[0250] In step SE10, the control unit 100 controls the bit movement motor 50 in this example through feedback control based on the rotation speed of the bit rotation motor 40, the rotation speed of the bit movement motor 50, the gear ratio of the reducer, etc. For example, the rotation speed is adjusted by increasing or decreasing the PWM output to the bit movement motor 50.

[0251] In step SE6, the control unit 100 determines that the rotation amount 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 SE11, the control unit 100 stops the drive of the bit rotation motor 40. In step SE12, the control unit stops the rotation of the bit movement motor 50 in the positive direction. In step SE13, the control unit 100 reverses the bit movement motor 50.

[0252] 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. ​​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 in the rearward direction.

[0253] In step SE14, if 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 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, then in step SE15, the reverse rotation of the bit moving motor 50 is stopped.

[0254] 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 by one or both of the bit rotation motor 40 and bit movement motor 50. Moreover, when a predetermined load is detected by one or both of the bit rotation motor 40 and 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.

[0255] 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 during feedback control execution after load detection and during feedback control non-execution before load detection. Normally, when providing PWM output to the motor, control is performed to stabilize the motor output by limiting the acceleration amount per unit time, particularly to prevent excessive acceleration current during startup. However, if the aforementioned feedback control is performed while acceleration is limited during startup of the bit movement motor 50, the PWM output generated in the feedback control is restricted and applied to the bit movement motor 50, thus deteriorating the responsiveness to feedback control. Therefore, during the execution of feedback control, it is preferable to set the acceleration limit value to be larger than during motor startup when feedback control is not executed.

[0256] Figure 25 This is a flowchart illustrating other variations of the operation of the fastening tool according to 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, other variations of the fastening operation of the fastening tool in this embodiment will be described. In this variation, the load applied to the bit movement motor 50 is detected, and the bit movement motor 50 is controlled.

[0257] 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.

[0258] Control unit 100 Figure 25 In step SF1, the rotation amount of the 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. 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.

[0259] 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.

[0260] 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.

[0261] 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.

[0262] 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 that is screwed into the object to be fastened.

[0263] In step SF6, the control unit 100 determines whether the rotation amount 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 amount 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, in step SF8, the control unit 100 controls the bit movement motor 50.

[0264] The bit moving motor 50 drives the holding member 30 and the moving member 32 to move forward. As a result, when the screw 200 is pressed against the object being fastened, in order to suppress the generation of excessive impact, the bit rotating motor 40 operates at the maximum output within the assumed range without reducing the tightening speed. Furthermore, the output of the bit moving motor 50 is limited by reducing the voltage applied to the bit moving motor 50 and reducing the current flowing through the bit moving motor 50.

[0265] If 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 becomes lower, then the advance of the screwdriver bit 2 generated by the bit movement motor 50 cannot keep up with the advance of the screw generated by the bit rotation motor 40, and thus it comes loose. On the other hand, if 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 becomes higher, then the advance of the screwdriver bit 2 generated by the bit movement motor 50 greatly exceeds the advance of the screw generated by the bit rotation motor 40, and therefore the operator needs to apply excessive force when pressing the fastening tool 1 towards the object being fastened.

[0266] 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 eliminates the need for excessive force from the operator to press the fastening tool 1 towards the object being fastened, thus preventing excessive impact when the screw 200 is pressed against the object.

[0267] 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, by limiting the output of the bit movement motor 50, the retaining member 30 and the moving member 32 can be decelerated when the screw 200 is pressed against the fastening object, and the effect of further suppressing the impact can be obtained.

[0268] 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 rotational 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 rotates forward at a first rotational 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 rotates forward at a second rotational speed with a reduced rotational 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 rotational speed, slower than the first rotational speed and faster than the second rotational speed, is used until the amount of rotation by which the bit rotation motor 40 rotates the screwdriver bit 2 to the end position of the operation becomes constant.

[0269] Furthermore, due to fluctuations in the power supply voltage, a difference arises in the moving speed (forward speed) of the holding component 30 and the moving component 32. 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.

[0270] Therefore, it is possible to suppress the difference in rotational speed of the bit movement motor 50 caused by fluctuations in the power supply voltage. As a result, when the screw 200 is pressed against the object being fastened, it is possible to suppress excessive impact and to suppress deviations in the speed at which the screw 200 is pressed against the object being fastened.

[0271] In step SF6, the control unit 100 determines that the rotation amount of the bit moving 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 SF9, the control unit 100 stops the drive of the bit rotating motor 40. After stopping the rotation of the bit moving motor 50 in the positive direction in step SF10, the control unit 100 reverses the bit moving motor 50 in step SF11.

[0272] 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. ​​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 in the rearward direction.

[0273] In step SF12, if 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 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, then in step SF13, the reverse rotation of the bit moving motor 50 is stopped.

[0274] Figure 27This is a flowchart illustrating other variations of the operation of the fastening tool according to this embodiment. Next, referring to the figures, other variations of the fastening operation of the fastening tool according to this embodiment will be described. In this variation, the load applied to the bit movement motor 50, etc., is detected to suppress drive in the absence of screws.

[0275] 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.

[0276] Control unit 100 Figure 27 In step SG1, the rotation amount of the bit movement motor 50, which determines the forward advance 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 activated. 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.

[0277] 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.

[0278] 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.

[0279] 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.

[0280] 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 that is screwed into the object to be fastened.

[0281] In step SG6, the control unit 100 determines whether the rotation amount 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 amount 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 one 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 rotation of the bit movement motor 50 in the positive direction continues until the rotation amount of the bit movement motor 50 reaches the set value selected by the setting unit 110.

[0282] In step SG6, the control unit 100 determines that the rotation amount 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 SG8, ​​the control unit 100 stops the drive of the bit rotation motor 40, and in step SG9, the control unit stops the rotation of the bit movement motor 50 in the positive direction. In step SG10, the control unit 100 reverses the bit movement motor 50.

[0283] 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. ​​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 in the rearward direction.

[0284] In step SG11, if 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 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, then in step SG12, the reverse rotation of the bit moving motor 50 is stopped.

[0285] 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 load applied to the bit rotation motor 40 and bit movement motor 50 will not increase because the screw 200 is not pressed against the object being fastened. Therefore, 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 loaded, if no predetermined load is detected, it can be determined that there is no screw 200.

[0286] 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 bit 2 mounted on the holding member 30 has advanced by a predetermined amount of idle rotation detection. Then, if the control unit 100 determines that a predetermined load has not been detected in one or both of the bit rotation motor 40 and the bit movement motor 50, and determines that the bit movement motor 50 has rotated by the predetermined amount of idle rotation detection, it determines that there is no screw 200 and issues an error notification in step SG14. In addition, 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.

[0287] The control unit 100 can also detect the load applied to one or both of the bit rotation motor 40 and the bit movement motor 50 based on changes in the current flowing through the motor, excluding current changes generated during motor startup. Alternatively, it can detect the load based on changes in the voltage flowing through the motor, excluding voltage changes generated during motor startup. Furthermore, a structure can be constructed 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.

[0288] Explanation of reference numerals in the attached figures

[0289] 1 Fastening tools 10 Tool body 10a 10b housing Front frame 10c Rear frame 10d Combined component 10e Screw 10f Nose body 11 Handle 12 Battery 13 Battery mounting section 2 Screwdriver bits 3 Bit holding section 30 Retaining component 30a Opening 30b Connecting component 31 Rotary guide component 31a Groove 32 Moving part 32a First moving part 32b Bearing (bearing) 32c Second moving part 33 Force-applying component 34a Bearing (4) First drive unit 40 Screwdriver bit rotary motor (motor, first motor) 40a Shaft 41 Gearbox 41a Shaft 42 Bearing (5) Second drive unit 50 Bit moving motor (motor, second motor) 50a Shaft 51 Gearbox 51a Shaft 52 Pulley (transmission component) 53 Bearing 54 Wire (transmission component) 6 Screw storage section 7 Screw feed section 70 Screw feed motor 71 Small Gear 72 Rack 73 Card Section 8 Head 80 Ejection path 81 Contact component 81a Ejection port 82 Contact arm 83 Adjustment Department 84 Contact switch section 9 Trigger 90 Trigger switch section 100 Control Unit 110 Setting Department

Claims

1. A fastening tool, comprising: The screwdriver bit holder holds the screwdriver bit in a detachable manner and is able to rotate circumferentially and move axially. A motor that performs at least one of rotating the bit holder and moving the bit holder axially; and The control unit controls the axial position of the bit holder by controlling the amount of rotation of the motor. The control unit determines the presence or absence of a screw based on the load applied to the motor that rotates in a direction that moves the bit holder toward the object to be fastened, and stops the rotation of the motor when it determines that there is no screw.

2. The fastening tool according to claim 1, wherein, When the rotation of the motor is stopped, the control unit causes the motor to rotate in another direction that moves the bit holder away from the object being fastened.

3. The fastening tool according to claim 1 or 2, wherein, The control unit notifies of an abnormality when it stops the rotation of the motor.

4. The fastening tool according to claim 1, wherein, When the bit holder moves in one direction by a distance based on the length of the minimum screw, the control unit determines the presence or absence of the screw based on the load applied to the motor.

5. The fastening tool according to claim 1 or 2, wherein, The load applied to the motor is detected based on changes in the current flowing through the motor, but does not include changes in the current generated when the motor starts.

6. The fastening tool according to claim 1 or 2, wherein, The load applied to the motor is detected based on changes in the voltage applied to the motor, but does not include voltage changes that occur when the motor starts.

7. The fastening tool according to claim 1 or 2, wherein, 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 stops the rotation of the first motor and the second motor based on one or both of the load applied to the first motor that rotates the bit holder in one direction toward the fastening screw and the load applied to the second motor that rotates in one direction toward the fastening object.

Images