JP6123552B2 - Fastener driving machine - Google Patents

Description

  The present invention relates to a fastener driving machine, and more particularly, to a spring-driven fastener driving machine in which a driving force for driving a fastener such as a nail, a hook or a staple into a driven member is applied by an electric motor.

  A spring-driven fastener driving machine to which a driving force is applied by an electric motor (hereinafter referred to as a motor) is disclosed in, for example, Patent Document 1 and is well known.

  In the spring-driven fastener driving machine, the plunger is moved by the driving force of the motor from the bottom dead center side, which is the direction opposite to the fastener driving direction, to the top dead center side. By this movement of the plunger, the spring (spring) is compressed and then released. When the spring is released, the plunger is biased by the compressed spring and moves from the top dead center side to the bottom dead center side. Fasteners such as nails, scissors and staples are driven into the driven member by a plunger accelerated by the biasing force of the spring.

  In the spring-driven fastener driving machine, in preparation for the next fastener driving operation, after driving the fastener, the plunger is pushed up again to the predetermined position by the driving force of the motor, and the plunger is moved to the predetermined position. In this state, it is desirable to stop the motor and complete the driving operation cycle. By doing so, it is possible to shorten the time for compressing the spring in the next driving operation.

JP 2009-166155 A

  In recent years, spring driven fastener driving machines have been required to allow larger nails to be driven.

  In order to meet this requirement, it is conceivable to increase the biasing force applied to the plunger by the driving spring, that is, the energy of the driving spring. However, if the energy of the spring is increased, the motor rotation speed, that is, the compression speed of the spring is increased against the large biasing force of the spring, and the plunger is moved quickly from the bottom dead center side to the top dead center side. Is required to stop the plunger at a predetermined position.

  However, when the compression speed of the spring is increased, the plunger stops from the bottom dead center, in other words, the compression of the spring, due to the rotational inertia of the motor and / or power transmission mechanism due to the change in mechanical loss with time. There will be variations in distance. When the driving operation is repeated, variations in the stop position of the plunger cause variations in the compression time of the spring in the next driving operation.

  In addition, when the plunger is stopped at a predetermined position (initial position) after driving, there is a variation in the stopping position so that two erroneous drivings do not occur by operating the operation switch in one driving operation. The position of the plunger must be controlled, i.e., the initial position of the plunger must not exceed the position of the starting point on the top dead center side when released from the spring. In other words, in consideration of the variation in the stop position, it is necessary to stop the position of the plunger in the initial state at a position closer to the bottom dead center than the driving start position. In this case, in order to prevent the occurrence of erroneous driving, it is conceivable that the position at which the plunger is stopped is set to the bottom dead center side, but in this case, the time required for compression of the spring after the operation switch is operated. Becomes longer.

  As described above, the variation in the compression time of the spring and the lengthening of the time required to compress the spring will deteriorate the driving efficiency.

  Patent Document 1 discloses that a spring is compressed by a plunger after driving. However, in Patent Document 1, it is not conscious to accurately control the position of the plunger with a simple configuration.

  An object of the present invention is to provide an efficient fastener driving machine with a simple configuration.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in the present application, the outline of typical ones will be briefly described as follows.

  That is, the fastener driving machine includes a plunger having a blade for driving the fastener, a spring that urges the plunger, a motor that moves the plunger, a spring compression drive unit, a control device, and a one-way clutch. The plunger can be moved between top dead center (first point) and bottom dead center (second point), and the spring can be compressed in the direction from bottom dead center to top dead center and released from compression. As a result, the plunger is urged from the top dead center to the bottom dead center. The spring compression drive unit compresses the spring by the rotation of the motor, and releases the spring when the rotation amount of the motor reaches a predetermined value (first value). In preparation for the next driving operation, the motor rotates after the spring is released. When the rotation amount of the motor after the spring is released reaches a second value from a predetermined value, the motor is stopped by the control device. When the motor is stopped, the spring compression is maintained by the one-way clutch.

  The timing for stopping the motor after the spring is released to drive the fastener is determined based on the amount of rotation of the motor. That is, the spring compression time for the next driving operation is determined based on the rotation amount of the motor. Since the position of the plunger from the bottom dead center depends on the time for which the spring is compressed, the second value is set appropriately so that the plunger is accurately positioned at the appropriate initial position for the next driving operation. Therefore, it is possible to provide an efficient fastener driving machine.

  In one embodiment, the fastener driving machine is provided with a detection circuit that detects the current flowing through the motor. When the spring is compressed, the value of the current flowing through the motor varies depending on the effectiveness of the spring. Therefore, when the spring changes from compression to release, in other words, when the plunger is biased by the compressed spring, a peak occurs in the value of the current flowing through the motor. The plunger can be moved to the initial position more accurately by obtaining the motor rotation amount and determining the timing to stop the motor from when this current peak is detected by the detection circuit. It becomes.

  In one embodiment, a brushless motor (hereinafter also simply referred to as a motor) is used as the motor. The brushless motor has a rotational position detection sensor (hereinafter also referred to as a magnetic pole sensor) that determines the position of the rotor. The amount of rotation of the motor is calculated using a detection signal from the rotor position detection sensor. Thereby, it is possible to obtain an efficient fastener driving machine with a simple configuration. Moreover, since it is a brushless motor, it is also possible to reduce the power consumption of the fastener driving machine.

  Furthermore, in one embodiment, the fastener driving machine includes a switch for instructing driving of the fastener. The amount of rotation of the motor from the time when the fastener is instructed until the peak of the current flowing through the motor is detected is calculated. The second value is changed based on the calculated rotation amount. When instructed to drive the fastener, the plunger is in the initial position. Therefore, the rotation amount calculated here depends on the distance from the initial position of the plunger to the position of the plunger when the spring is released. Based on the rotation amount calculated here, it is possible to change the position of the initial state by changing the second value, and in the movement of the plunger in preparation for the next driving operation, a more accurate initial state It is possible to move the plunger to the position, and it is possible to provide a more efficient fastener driving machine.

  Of the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

  An efficient fastener driving machine can be provided with a simple configuration.

It is a side view including the partial cross section of the fastener driving machine concerning one embodiment. It is a top view including the partial cross section of the fastener driving machine shown in FIG. It is a rear view including the partial cross section of the fastener driving machine shown in FIG. It is a perspective view of the spring compression drive part which comprises the fastener driving machine shown in FIG. It is the disassembled perspective view which decomposed | disassembled some spring compression drive parts shown in FIG. It is the disassembled perspective view which decomposed | disassembled the whole spring compression drive part shown in FIG. It is a perspective view which shows the reference | standard state of the drum in the spring compression drive part shown in FIG. FIG. 6 is a perspective view illustrating a state in which a drum in the spring compression driving unit illustrated in FIG. 5 is rotated 135 degrees. It is a perspective view which shows the state which the drum in the spring compression drive part shown in FIG. 5 rotated 270 degree | times. FIG. 6 is a perspective view illustrating a state in which a drum in the spring compression driving unit illustrated in FIG. 5 is reversely rotated. It is a block diagram which shows the structure of the control apparatus and the motor which were built in the fastener driving machine shown in FIG. (A)-(F) are timing chart figures which show operation | movement of the fastener driving device 1 by the control apparatus 50. FIG. FIG. 12 is a flowchart showing the operation of a microcomputer 53 provided in the control device 50 shown in FIG. 11. It is a schematic diagram which shows the structure of a brushless motor.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

(Embodiment 1)
In the following description, an example will be described in which the fastener driven into the driven member is injected from the fastener driving machine to the driven member in the horizontal direction. In this case, in the fastener driving machine, the plunger or the like also moves in the horizontal direction, but for the sake of convenience of description, it is expressed as the vertical direction. However, it is only for convenience and is not limited to this. For example, if the fastener is ejected from the fastener driving machine to the driven member in the vertical direction, the vertical direction may be regarded as the vertical direction.

  The configuration of the fastener driving machine and the operation thereof will be sequentially described below.

<Configuration of fastener driving machine>
FIG. 1 is a side view showing the overall configuration of a spring-driven fastener driving machine. This side view is the figure which looked at the cross section of the fastener driving machine from the side. In the figure, reference numeral 1 denotes a fastener driving machine. The fastener driving machine 1 includes a body housing portion 2, a handle housing portion 3 that is branched from the body housing portion 2, and a battery pack (storage battery) 4 that is detachably attached to the end of the handle housing portion 3. I have. Further, the fastener driving machine 1 includes a nose (injection portion) 5 provided on the front end side (lower end side) of the fastener in the trunk housing portion 2 and a plurality of fasteners connected to each other (injection portion). For example, a nail) 23 is loaded, and a magazine 6 for supplying the fasteners 23 one by one is provided in the injection portion passage 5 a of the nose 5.

  The battery pack 4 is electrically connected to the motor 7 (FIGS. 2, 3, 11 and 14) via an inverter 51 (FIG. 11) which will be described later by being mounted on the handle housing portion 3. The battery pack 4 is also electrically connected to the control device 50 described later by being attached.

  The body housing part 2 obtains a large torque by reducing the rotational speed of the plunger 8, a driving spring (coil spring 9) for applying a striking force (elastic force) to the plunger 8, the motor 7, and the motor 7. A reduction mechanism 80 (FIG. 3) is incorporated. Further, the body housing portion 2 is driven by the motor 7 via the speed reduction mechanism portion 80, and a spring compression / release mechanism portion 81 for compressing and releasing (extending) a driving spring (hereinafter also referred to as a spring) 9. (Hereinafter referred to as a spring compression drive unit). As will be described later with reference to FIG. 3, the spring compression drive unit 81 includes a wire or rope (winding connection line) 16, a drum (rotating body) 13, a drum hook 22, a pin support plate 21, A power transmission pin 17 and a guide plate 18 are provided.

  As shown in FIG. 1, the handle housing portion 3 extends from the outer peripheral surface of the trunk housing portion 2 with the side surface of the trunk housing portion 2 as a base end portion. A trigger 10 that controls activation of the motor 7 is provided at the proximal end of the handle housing portion 3. An operation on the trigger 10 is detected by the trigger switch 54, and the result detected by the trigger switch 54 is electrically transmitted to the control device 50. The handle housing portion 3 is provided with a control device 50, and the battery pack 4 is attached to the other end portion of the handle housing portion 3, and electric power from the battery pack 4 is provided by wiring arranged in the handle housing portion 3. Is supplied to the motor 7 via the control device 50 and the inverter 51.

  As shown in FIG. 1, the magazine 6 is provided so as to extend from one end located at the nose 5 to the other end located at the handle housing portion 3. A plurality of nails as the fasteners 23 are loaded in the magazine 6 so as to be connected in the extending direction of the magazine 6. The plurality of nails (fasteners 23) connected to each other are pressed to the nose 5 side by the feeding member 6a so that the end portions thereof are always located in the injection portion passage 5a of the nose 5. As a result, the fastener 23 located in the injection portion passage 5a is hit by the tip portion of the blade 8a when the tip portion of the blade 8a moves into the injection portion passage 5a of the nose 5, as will be described later. It is pushed out from the injection portion passage 5a of the nose 5 and driven into a driven member (not shown). Further, by making the length of the injection portion passage 5a of the nose 5 longer than the length of the fastener 23 (nail) to be driven, the plunger 8 (plate 8a) is moved until the hit nail contacts the driven member. It is possible to accelerate and apply a strong striking force to the nail as the fastener 23.

  A push switch (push lever) 55 is provided at the tip of the nose 5 for detecting that the tip of the nose 5 substantially contacts the driven member. As will be described later, the push switch 55 and the trigger switch 54 that detects the operation of the trigger 10 function as an operation switch that controls the operation of the motor 7. The push switch 55 and the trigger switch 54 are turned on / off. , And supplied to the control device 50 as a control signal.

  As shown in FIG. 1, the plunger 8 has an upward direction A (solid arrow) between the top dead center (first point) side and the bottom dead center (second point) side of the body housing portion 2. Or it is arrange | positioned so that an up-down movement is possible in the downward direction B (dashed arrow). That is, the plunger 8 is disposed in the cylindrical portion of the body housing portion 2 shown in the central portion of FIG. 1 and is movable between the top dead center and the bottom dead center. Here, the bottom dead center side means the nose 5 side, and the top dead center side means the side opposite to the nose 5. The plunger 8 has a blade (driver blade) 8a. When the plunger main body 8 moves to the bottom dead center side (downward direction B), the tip of the blade 8a is a fastener defined in the nose 5 ( It moves (extends) to the tip of the injection passage 5a in which the nail 23 is loaded.

  A spring (coil spring) 9 is installed in a compressible state between a top dead center side upper surface portion of the plunger plate 8b of the plunger 8 and a wall portion 2a surrounding a spring compressor moving portion 81 described later. As will be described later, the wire 16 is wound up by the spring compression drive unit 81. By this winding operation, the plunger 8 is moved to the top dead center side (upward direction A). That is, the plunger 8 is wound up to the top dead center side by the winding operation. The spring 9 is compressed by the plunger 8 being wound up toward the top dead center. After being compressed, the spring 9 is released. Thereby, the plunger 8 is biased by the spring 9. That is, the plunger 8 is pressed with a stronger biasing force by the spring 9 in a direction from the top dead center side to the bottom dead center side (driving direction: downward direction B).

  FIG. 2 is a top view of the fastener driving machine 1 shown in FIG. 1 as viewed from above. Like FIG. 1, FIG. 2 is the figure which looked at the cross section of the fastener driving machine 1 from the upper surface. 2, the same parts as those in FIG. 1 are denoted by the same reference numerals, and therefore only the parts not described in FIG. 1 will be described.

  In FIG. 2, 7 is the motor described above. In FIG. 2, 12 is a damper and 13C is a drum damper. The damper 12 is installed on the bottom dead center side in the body housing portion 2. The damper 12 has a function of mitigating an impact when the plunger 8 biased by the spring 9 moves to the bottom dead center side and collides with the bottom dead center side of the body housing portion 2. On the other hand, the drum damper 13c has a function of mitigating an impact generated when the drum 13 rotates in the reverse direction, as will be described later.

  FIG. 3 is a rear view of the fastener driving machine 1 as viewed from behind. FIG. 3 is also a view of the cross section of the fastener driving machine 1 as viewed from the back. FIG. 3 shows in more detail the configurations of the motor 7, the speed reduction mechanism portion 80, and the spring compression drive portion 81 described above.

  As shown in FIG. 3, the motor 7 has rotation output shafts 7a at both ends thereof. The speed reduction mechanism unit 80 is provided in cooperation with the motor 7. That is, the first pulley 14 attached to the rotation output shaft 7 a (upper side in FIG. 3) of the motor 7 is a component constituting the speed reduction mechanism unit 80. The speed reduction mechanism unit 80 includes the first pulley 14, the belt 40, the second pulley 15, and the planetary gear 11.

  The rotation of the first pulley 14 is transmitted to the second pulley 15 by the belt 40. Thereby, the first pulley 14 and the second pulley 15 transmit the rotation of the rotation output shaft 7 a of the motor 7 to the rotation output shaft 15 a of the second pulley 15. By setting the ratio of the first pulley 14 and the second pulley 15, the rotation speed of the rotation output shaft 7 a of the motor 7 is reduced, and the rotation speed of the rotation output shaft 15 a of the second pulley 15 is reduced. The rotation speed is set. That is, the first pulley 14 and the second pulley 15 constitute a first speed reduction unit that attenuates the rotational speed of the rotation output shaft 7 a of the motor 7.

  The planetary gear 11 includes a three-stage planetary gear unit that is linked to the rotation output shaft 15 a of the second pulley 15. The rotation speed of the rotation output shaft 15 a of the second pulley 15 is a further reduced rotation speed on the rotation output shaft 19 of the planetary gear 11. In other words, in this embodiment, the planetary gear 11 constitutes the second speed reducing unit.

  As will be described later, the drum 13 that is a rotating body is connected to the rotation output shaft 19 of the planetary gear 11 (second reduction gear), and is driven by the reduced rotational force obtained by the rotation output shaft 19. . The drum 13 is driven to wind up the wire 16 and move the plunger 8 to the top dead center side. The rotation of the rotation output shaft 7 a of the motor 7 is decelerated on the rotation shaft 19 of the drum 13 by the reduction mechanism 80. As a result of the deceleration, the torque (rotational force) of the rotating shaft 19 of the drum 13 is amplified by the torque of the motor 7. Therefore, it is possible to configure a compression mechanism that compresses the spring 9 by applying a small motor as the motor 7. For example, the reduction ratio between the rotation output shaft 7a of the motor 7 and the rotation output shaft 19 of the drum 13 (the rotation output shaft 19 of the speed reduction mechanism unit 80) is 150 to 300.

  A one-way clutch (reverse rotation prevention mechanism) 24 fixed to the attachment portion 2 b of the body housing portion 2 is installed on the rotation output shaft 7 a (lower side in FIG. 3) of the motor 7. As will be described later, the one-way clutch 24 allows the motor 7 (drum 13) to rotate only in the forward rotation direction (A direction: predetermined direction) and rotates in the reverse rotation direction (B direction). It is provided to suppress (prohibit). That is, when a torque is applied to the rotation output shaft 7a of the motor 7 so that the drum 13 rotates in the direction B opposite to the direction A in which the wire 16 is wound up, the counter torque in the reverse direction B is overcome. It has a function to prevent rotation.

  Further, when the drum 13 is connected to the rotation output shaft 7a of the motor 7 by a spring compression drive unit 81 and a speed reduction mechanism unit 80, which will be described later, even if the motor 7 is stopped, the drum 13 Is applied in the reverse direction B, the one-way clutch 24 prevents the rotation output shaft 7a of the motor 7 and the drum 13 from rotating in the reverse direction B. That is, the one-way clutch 24 has a function of preventing rotation in the reverse direction B regardless of whether the motor 7 is operating. On the other hand, when the connection between the rotation output shaft 7a of the motor 7 and the drum 13 is released by the spring compression drive unit 81 described later, the drum 13 is applied with a torque for rotating it in the reverse direction B. In this case, it is possible to rotate in the reverse direction B.

  Of course, when a torque for rotating in the positive direction A is applied, the one-way clutch 24 allows rotation in the positive direction A (idling) with respect to torque exceeding the loss torque in the one-way clutch. . As the one-way clutch 24, a roller type (roller type) clutch or a ratchet type clutch can be applied. For example, a one-way clutch as disclosed in Patent Document 1 can be used as the one-way clutch 24.

<Configuration of Spring Compression Drive Unit 81>
4 is a perspective view showing the configuration of the spring compression drive unit 81, FIG. 5 is an exploded perspective view of a part of the spring compression drive unit 81, and FIG. 6 is an exploded view of the whole spring compression drive unit 81. It is a perspective view.

  The spring compression drive unit 81 compresses and releases the spring 9 (FIGS. 1 and 2). 4 to 6, the spring compression drive unit 81 includes a guide plate 18, a pin support plate 21, a drum hook 22, a drum 13, a power transmission pin 17, and a wire 16. FIG. 6 shows a state where the drum 13 is removed from the drum hook 22 (disassembled state).

  The guide plate 18 has a guide groove 18a and a guide projection 18b, and supports one end of the rotation output shaft 19 of the planetary gear 11 so as to be rotatable. The rotation output shaft 19 of the planetary gear 11 has a key 20, and the key 20 is rotated by the rotation of the rotation output shaft 19. The pin support plate 21 has a pin support slide portion 21a and a key groove 21b. The key 20 of the output rotation shaft 19 is connected to the key groove 21b. The pin support plate 21 is rotated by the rotation of the rotation output shaft 19. Rotate. The power transmission pin 17 has a pin slide portion 17a and a pin hooking portion 17b. The pin slide portion 17a is slidably fitted into and supported by the pin support slide portion 21a of the pin support plate 21.

  The drum hook 22 has a hook portion 22a and a bearing 22b. The outer peripheral surface of the drum hook 22 is coupled to the drum 13, and the inner peripheral surface of the drum hook 22 is coupled to the rotary output shaft 19 via the bearing 22b. ing. As will be described later, the hook portion 22a of the drum hook 22 is caught by the pin hooking portion 17b of the power transmission pin 17 during the period in which the power transmission pin 17 rotates in synchronization with the rotation of the rotation output shaft 19. There is a period of being engaged (engaged) and a period of being disengaged. During the period in which the pin hooking portion 17b is hooked (engaged) with the power transmission pin 17, the drum hook 22 is driven by the rotation of the rotation output shaft 19, and the drum 13 coupled to the drum hook 22 is also driven. Is done. On the other hand, during a period in which the pin hooking portion 17 b is detached from the power transmission pin 17, the drum hook 22 and the drum 13 are separated from the rotation output shaft 19 and freely rotate with respect to the rotation output shaft 19. That is, during this period, the driving force by the rotation output shaft 19 is cut off, and the drum 13 rotates freely.

  The drum 13 has a drum damper engaging portion 13a and a drum valley portion (groove portion) 13b. A wire 16 is joined to the drum valley portion 13b, and the wire 16 is wound around the drum 13 by rotating the drum 13 in a predetermined direction. As will be described later, when the drum 13 is driven by the rotation output shaft 19, the drum 13 rotates in a predetermined direction. When the drum 13 is separated from the rotation output shaft 19, the drum 13 can rotate in a direction opposite to the predetermined direction described above. A drum damper engaging portion 13a is provided so that the drum 13 stops at a predetermined position when the drum 13 rotates in the reverse direction. When the drum 13 reaches a predetermined position, the drum damper engaging portion 13a reaches the drum damper 13c shown in FIG. 1, and the drum 13 is stopped by the drum damper 13c.

  In the spring compression drive unit 81, the driving force of the motor 7 transmitted through the speed reduction mechanism unit 80 is transmitted to the drum 13. The drum 13 rotates in a predetermined direction by the driving force of the motor 7, and rotates from its reference state (rotation angle is about 0 degrees) to a predetermined rotation angle (for example, a predetermined rotation angle exceeding about 270 degrees). However, the wire 16 is wound up in the direction indicated by the solid arrow A to compress the driving spring 9. When the drum 13 reaches a predetermined rotation angle (a predetermined rotation angle exceeding about 270 degrees), the coupling between the rotation output shaft 19 and the rotation shaft of the drum 13 is cut, and the drum 13 is connected to the rotation output shaft 19. And is supported for free rotation. As a result, the wire 16 moves in the direction B indicated by the broken line by the urging force of the driven driving spring 9, and the drum 13 rotates in the direction opposite to the predetermined direction. At this time, the compressed driving spring 9 is suddenly released. Due to the spring energy of the released driving spring 9, the blade 8 a of the plunger 8 shown in FIGS. 1 and 2 strikes the nail as the fastener 23.

  In this manner, the spring compression drive unit 81 has a function of compressing the driving spring 9 until the rotational position of the drum (rotating body) 13 reaches the predetermined rotational angle (predetermined position) from the reference state. When the rotational position of reaches a predetermined position, it has a function of releasing the driving spring 9. That is, the spring compression drive unit 81 transmits the driving force of the motor 7 obtained on the rotation output shaft 19 of the speed reduction mechanism unit 80 to the drum 13 to compress the spring 9 and the driving force of the motor 7. It has the function of cutting the transmission and releasing the compressed spring 9. In this case, switching between the two functions is performed depending on whether or not the rotation position (rotation angle) of the drum (rotating body) 13 reaches a predetermined position.

  Furthermore, this spring compression drive part 81 is demonstrated in detail using FIGS. 4-6. In order to compress the driving spring 9, the spring 9 is coupled to the drum 13 via a plunger 8 by means of a winding connection line. In the embodiment, the wire 16 is used as the winding connection line. The wire 16 is configured by bundling a plurality of metal wires, and has both flexibility and strength. Further, the surface of the wire 16 is coated with a resin so as to reduce wear of members of the drum groove portion 13b that contacts the wire 16.

  The outer peripheral surface of the cylindrical portion of the drum hook 22 is press-fitted into the center hole of the drum 13 as shown in FIG. 6, and the drum hook 22 and the drum 13 are inserted into the drum 13 as shown in FIGS. It is integrated. A bearing (for example, a ball bearing) 22 b is press-fitted into the inner peripheral surface of the cylindrical portion of the drum hook 22, and the bearing 22 b is installed on the rotary output shaft 19. That is, the inner peripheral surface of the cylindrical portion of the drum hook 22 is in contact with the rotation output shaft 19 with the bearing 22b interposed therebetween. Thus, the drum 13 and the drum hook 22 are integrally supported by the rotary output shaft 19 so as to be rotatable.

  The power transmission pin 17 has a pin slide part (groove part) 17 a that engages with a pin support slide part 21 a provided on the pin support plate 21, and a pin hook part 17 b that engages with a hook part 22 a of the drum hook 22. doing. Here, the pin slide part 17a is engaged with the pin support slide part 21a which the pin support plate 21 has so that a slide is possible. The power transmission pin 17 is installed so that its side end surface abuts against a wall portion in the guide groove 18a provided in the guide plate 18, and the movement direction and the movement amount of the power transmission pin 17 are the same as those of the guide groove 18a. It is controlled by the planar shape. The pin hooking portion 17 b, which is the other end surface of the power transmission pin 17, is installed at the same height as the hook portion 22 a in the axial direction of the rotation output shaft 19, and is synchronized with the pin support plate 21. When the is rotating, the pin hooking portion 17b and the hook portion 22a are engaged.

  The pin support plate 21 has a key groove 21 b, and the key groove 21 b is locked to a key 20 that is a protrusion provided on the rotation output shaft 19. As a result, the three members of the rotation output shaft 19, the pin support plate 21, and the power transmission pin 17 are configured to always rotate in synchronization.

  As shown in FIGS. 5 and 6, the guide groove 18 a is provided around the rotation output shaft 19, but a guide protrusion 18 b is provided around the rotation output shaft 19. The planar distance between the rotation output shaft 19 and the wall portion of the guide groove 18b differs in the planar position of the guide groove 18b. When the pin support plate 21 and the power transmission pin 17 rotate in synchronization with the rotation of the rotation output shaft 19, the planar distance between the rotation output shaft 19 and the wall portion of the guide groove 18 a is changed. Thus, the power transmission pin 17 slides the pin support slide portion 21a of the pin support plate 21 in the radial direction. By sliding, the distance on the plane between the rotation output shaft 19 and the power transmission pin 17 changes. That is, when the power transmission pin 17 rotates in synchronization with the rotation of the rotation output shaft 19, the plane between the rotation output shaft 19 and the power transmission pin 17 is matched to the planar shape of the guide groove 18 a. The distance at changes.

  The hook portion 22a of the drum hook 22 engages with the pin hook portion 17b of the power transmission pin 17 when the distance on the plane between the rotation output shaft 19 and the power transmission pin 17 is smaller than a predetermined value. On the other hand, when the planar distance between the rotation output shaft 19 and the power transmission pin 17 becomes larger than a predetermined value, the distance (on the plane) between the pin hooking portion 17b of the power transmission pin 17 and the hook portion 22a ( A clearance) is generated, and the engagement between the pin hooking portion 17b and the hook portion 22a is released. By releasing the engagement between the pin hooking portion 17b and the hook portion 22a, the drum 13 integrated with the drum hook 22 is separated from the rotation output shaft 19 and can be rotated in a free direction. . In other words, when the drum (rotating body) 13 is rotated to a predetermined position by the driving force of the motor 7, the hook portion 22a is detached from the power transmission pin 17 and released from the driving force of the motor 7, so that the direction is free. Can be rotated.

<Operation of Spring Compression Drive Unit 81>
7 to 9 are perspective views showing the rotation state of the drum 13 when the spring compression drive unit 81 is operating. FIG. 10 is a perspective view showing a state where the drum 13 rotates in the reverse direction. 7 to 10, the drum 13 integrated with the drum hook 22 by press-fitting is omitted for easy understanding of the respective states. That is, a state in which the drum 13 is removed from the drum hook 22 is shown in these perspective views. In this embodiment, although not particularly limited, the rotation position (rotation angle) of the drum (rotating body) 13 is represented by the rotation position (rotation angle) of the hook portion 22 a of the drum hook 22 integrated with the drum 13. In FIG. 7, it is assumed that the lower side is 0 degree, and the rotation angle increases counterclockwise to 90 degrees, 180 degrees, and 270 degrees.

  FIG. 7 shows a state where the drum 13 is in the reference state. In the reference state, the rotation angle of the hook portion 22a of the drum hook 22 integrated with the drum 13 is about 0 degree, and the rotation position of the drum 13 is about 0 degree. In this reference state, since the hook portion 22a and the power transmission pin 17 are engaged, the rotation angle of the pin support plate 21 is also at the 0 degree position. In this reference state, the plunger 8 (FIGS. 1 and 2) is stopped on the bottom dead center side. In the figure, arrow A indicates the direction in which the rotation output shaft 19, in other words, the pin support plate 21 and the power transmission pin 17 rotate. In this embodiment, the rotation direction of the arrow A is the normal rotation direction. The direction opposite to arrow A is referred to as A, and the reverse rotation direction B (dashed arrow B).

  FIG. 8 shows a state where the rotation output shaft 19 is rotated by the driving force of the motor 7 and the hook portion 22a (drum 13) is rotated about 135 degrees in the normal rotation direction A from the reference state. Yes. Further, FIG. 9 shows a state in which the hook portion 22a (drum 13) further rotates from FIG. 8 and rotates about 270 degrees in the normal rotation direction A from the reference state. Thus, when the rotation output shaft 19 rotates in the normal rotation direction A, the region engaged between the hook portion 22a and the pin hooking portion 17b gradually decreases. In FIG. 10, when the rotation output shaft 19 rotates, there is no area engaged between the hook portion 22a and the pin hooking portion 17b, and the hook portion 22a is engaged with the pin hooking portion 17b. A state is shown in which a biasing force is applied to the plunger 8 by the spring 9 (FIGS. 1 and 2) released from the joint and compressed, and the drum 13 rotates in the reverse rotation direction B.

  By moving the plunger 8 from the bottom dead center side to the top dead center side, the plunger 8 receives the urging force of the spring 9. The above-described spring compression drive unit 81 moves the plunger 8 from the bottom dead center side (reference state) to the top dead center side while resisting this urging force to compress the spring 9. That is, the plunger 8 which is spring-biased by the spring 9 is moved to a predetermined position on the top dead center side while resisting the spring biasing force (elastic force) by the operation of the motor 7, the speed reduction mechanism portion 80 and the spring compression drive portion 81. Push up. After being pushed up, the compressed spring 9 is released by the operation of the spring compression drive unit 81, and the spring force (striking force) of the spring 9 obtained at the time of release is given to the blade 8a attached to the plunger 8. The blade 8a applies the applied striking force to the fasteners (nails) 23 loaded in the magazine 6 (FIG. 1). As a result, the fastener (nail) 23 is driven from the nose 5 (FIGS. 1 and 2) toward the driven member. Next, operation | movement of the spring compression drive part 81 is demonstrated in detail using FIGS. 7-10.

  In the reference state where the plunger 8 (FIGS. 1 and 2) is stopped on the bottom dead center side, the plunger 8 is pressed toward the bottom dead center side by the biasing force of the spring 9. At this time, the pin hooking portion 17b for driving the drum 13 that winds up the wire 16 used to compress the spring 9 is in a reference state as shown in FIG. 7, for example. For example, in such a reference state, the operator grips the handle housing portion 3 (FIG. 1) of the fastener driving machine 1, pulls in the trigger 10, and turns on the trigger switch 54. At this time, when the push switch 55 provided at the tip of the nose 5 is pressed against the driven member, power is supplied from the battery pack 4 to the motor 7 by the function of the control device 50 (FIG. 2). Rotate in rotation direction A.

  As described in FIG. 3, the rotational force of the motor 7 is generated by the first pulley 14, the second pulley 15, the first pulley 14, and the second pulley attached to the rotation output shaft 7a. 15 is transmitted to the rotation output shaft 15a of the first reduction gear unit constituted by the belt 40 wound around the belt 15. The rotational force of the rotation output shaft 15a of the first reduction gear is transmitted to the rotation output shaft 19 by the second reduction gear constituted by the three-stage planetary gear 11. The rotational force of the rotation output shaft 19 is transmitted to the pin support plate 21 and the power transmission pin 17 mechanically coupled to the rotation output shaft 19. At this time, since the motor 7 is rotating in the normal rotation direction A, the one-way clutch 24 coupled to the rotation output shaft 7a of the motor 7 rotates idly. That is, at this time, the one-way clutch 24 allows the motor 7 to rotate in the normal rotation direction A.

  When the spring compression drive unit 81 is in the reference state (when the rotational position of the drum 13 is about 0 degrees), that is, in the state shown in FIG. 7, the power transmission pin 17 and the hook portion 22a are engaged. For this reason, when the pin support plate 21 receives the rotational force of the motor 7 and rotates, the drum hook 22 and the drum 13 rotate in the normal rotation direction A. When the drum 13 rotates in the forward rotation direction A, the wire 16 is wound into the drum groove portion 13b provided on the outer peripheral surface thereof. That is, the wire 16 is wound around the drum 13 so as to move in the direction A indicated by the solid arrow in FIGS. 1, 2, and 4. As the wire 16 moves in the direction A, the plunger 8 coupled to the end of the wire 16 as shown in FIGS. 1 and 2 moves toward the top dead center against the biasing force of the spring 9. It is pushed up and moves to the top dead center. As the plunger 8 moves to the top dead center side, the spring 9 is further compressed by the plunger plate 8b (FIGS. 1 and 2) provided on the upper end surface of the plunger 8.

  FIG. 8 shows a state in which the motor 7 rotates in the normal rotation direction A from the reference state shown in FIG. 7 and the hook portion 22a (drum 13) rotates about 135 degrees from the reference state in FIG. . In this state, the power transmission pin 17 is engaged with the hook portion 22a. Therefore, in synchronization with the rotation of the pin support plate 21, the drum 13 is also rotated about 135 degrees. As the drum 13 rotates about 135 degrees, the wire 16 is further wound into the drum groove 13b of the drum 13, and the wire 16 further moves in the direction A. As a result, the spring 9 is further compressed.

  When the motor 7 further rotates in the forward rotation direction A, the hook portion 22a (drum 13) rotates from the state of about 135 degrees shown in FIG. 8 to the state of about 270 degrees shown in FIG. As the rotation from the state of about 135 degrees to the state of about 270 degrees, the side end of the power transmission pin 17 comes into contact with the guide protrusion 18b that defines the inner peripheral wall of the guide groove 18a. The planar shape of the guide protrusion 18b has an approximately elliptical shape that swells about 5 to 15 mm from the center of the rotation output shaft 19 in the radial direction on the left side in FIGS. When considered as an elliptical shape, the guide protrusion 18 is eccentric from the rotation output shaft 19 to the left in FIGS. As the pin support plate 21 (drum 13) rotates from about 135 degrees to about 270 degrees, the power transmission pin 17 moves along the outer peripheral shape of the guide protrusion 18b. As the guide projection 18b moves along the outer peripheral shape, the power transmission pin 17 slides on the pin support slide portion 21a (FIG. 6) and moves in the radial direction far from the rotation output shaft 19.

  When the pin support plate 21 (drum 13) rotates from the reference state shown in FIG. 7 to the state of about 270 degrees shown in FIG. 9, the power transmission pin 17 moves about 5 to 15 mm in the radial direction. When the angle exceeds about 270 degrees, the hook (engagement) between the power transmission pin 17 and the hook portion 22a is released. During a period in which the power transmission pin 17 is engaged with the hook portion 22a, that is, a period from the reference state (FIG. 7) to about 270 degrees (FIG. 9), the drum 13 rotates in synchronization with the pin support plate 21. When the drum 13 is rotated to about 270 degrees, the plunger 8 is lifted by the wire 16 to the highest position on the top dead center side. That is, when the drum 13 is rotated to about 270 degrees, the spring 9 is in the most compressed state.

  When the pin support plate 21 (drum 13) rotates beyond about 270 degrees, the hook (engagement) between the power transmission pin 17 and the hook portion 22a is released. Thereby, the compressed spring 9 is released, and the plunger 8 moves to the bottom dead center side by the release force (elastic force) of the spring 9. When the plunger 8 moves to the bottom dead center side, it is pulled by the wire 16, and the drum 13 and the drum hook 22 start to rotate in the reverse rotation direction B opposite to the normal rotation direction A of the rotation output shaft 19 (FIG. 10). ). The drum 13 is not rotated in the reverse rotation direction B by the one-way clutch 24 until the hook (engagement) between the power transmission pin 17 and the hook portion 22a is released. However, when the catch (engagement) between the power transmission pin 17 and the hook portion 22a is released, the drum 13 can be rotated in the reverse rotation direction B without being restricted by the one-way clutch 24. It becomes.

  When the drum 13 rotates in the reverse rotation direction B by the release force of the compressed spring 9 and the plunger 8 moves to the bottom dead center side, the blade 8a attached to the plunger 8 passes through the injection portion passage 5a of the nose 5. Thus, the fastener (nail) 23 can be driven into the driven member. At the same time as this driving, the drum 13 returns to the reference state (FIG. 7). When returning to the reference state, the drum damper engaging portion 13a (FIG. 8) provided in the drum 13 engages with the drum damper 13c fixed in the body housing portion 2, and the hooks of the drum 13 and the drum hook 22 are engaged. The part 22a is engaged again at the position of the reference state shown in FIG.

  As will be described later, even after the fastener (nail) 23 is driven into the driven member, the motor 7 is driven by the control device 50 for a predetermined time. Thereby, the hook part 22a (drum 13) starts to rotate again in the normal rotation direction A by the power transmission pin 17 to which it is re-engaged. As the drum 13 rotates again in the normal rotation direction A, as described above, the wire 16 is caught in the drum 13, the plunger 8 moves to the top dead center side, and the spring 9 has a biasing force. Compressed.

  In this embodiment, after driving the fastener 23, the motor 7 is driven for a time (predetermined time) until the plunger 8 reaches a predetermined position on the top dead center side. Here, the predetermined position is a position closer to the bottom dead center side than the position of the plunger 8 when releasing the compressed spring 9 in order to drive the fastener 23. During the period in which the plunger 8 is moved to the top dead center side against the urging force of the spring 9, the position of the plunger 8 is proportional to the rotational position (rotation angle) of the drum (rotating body) 13. For example, the position of the plunger 8 when releasing the compressed spring 9 in order to perform driving corresponds to a predetermined position where the rotational position of the drum 13 exceeds about 270 degrees in the above description. In this case, the predetermined position of the plunger 8 corresponds to a position where the rotational position of the drum 13 is about 200 degrees in this embodiment. That is, the time until the rotation position (rotation angle) of the drum 13 reaches about 200 degrees is set as a predetermined time. Of course, the predetermined time for the rotational position of the rotating body (drum 13) to reach about 200 degrees varies depending on the driving torque of the motor 7 and the like.

  A state where the plunger 8 is stopped at a predetermined position on the top dead center side, that is, a state where the drum 13 is stopped at a predetermined rotational position is an initial state of the next driving cycle. For example, when the push switch 55 is turned on and the next driving cycle is started, the drum 7 is moved from the predetermined rotational position (about 200 degrees) held by the motor 7 to the drum 13 by the motor 7. It is driven to rotate toward the rotational position to release (a predetermined position exceeding about 270 degrees). Thereby, the plunger 8 is also moved toward the top dead center side from the predetermined position held in the initial state. When the drum 13 reaches the rotational position where the spring 9 is released, the plunger 8 is moved to the bottom dead center side by the biasing force of the spring 9, and the fastener 23 is driven. Thereafter, the same operation is repeated.

  As described above, in this embodiment, the drum 13 is rotated again, and the motor 7 is stopped when the rotational position of the drum 13 reaches a predetermined rotational position. When the motor 7 stops, the biasing force of the compressed spring 9 acts on the plunger 8 and the drum 13. That is, the biasing force of the compressed spring 9 acts so that the plunger 8 is moved to the bottom dead center side and the drum 13 is rotated in the reverse rotation direction B. However, in this embodiment, the power transmission pin 17 is engaged with the slit of the pin support slide portion 21a. Therefore, the biasing force of the compressed spring 9 is transmitted to the rotation output shaft 7a of the motor 7 via the plunger 8, the wire 16, the drum 13, the pin support plate 21, the power transmission pin 17, and the rotation output shaft 19. The That is, the biasing force of the spring 9 at this time acts to rotate the rotation output shaft 7a of the motor 7 in the reverse direction. At this time, the one-way clutch 24 prevents the rotation output shaft 7a from rotating in the reverse direction. Thereby, even if the motor 7 is stopped after the drum 13 is rotated again, the rotation position of the drum 13 and the position of the plunger 8 are maintained in the initial state.

  Even when the motor 7 is stopped, the drum 13, the rotor 13 of the motor 7, the planetary gear 11, the rotation output shaft 19 and the like move so as to continue rotating due to the rotation inertia. The timing for stopping the motor 7 is determined in consideration of the rotational position of the drum 13 due to this rotational inertia.

<Configuration of Control Device 50>
Next, the configuration of the control device 50 will be described. FIG. 11 is a block diagram illustrating a configuration of the control device 50. In FIG. 11, not only the control device 50 but also the motor 7, the inverter 51, the magnetic pole sensor (Hall element) 52, and the battery pack 4 (described as a battery in FIG. 11) are shown for easy understanding. Yes.

  The battery pack 4 includes, for example, a lithium ion secondary battery, and functions as a power source that supplies power to the inverter 51 and the control device 50. In this embodiment, a brushless motor is used as the motor 7. The brushless motor has a stator and a rotor, and a plurality of field windings (for example, three field windings) to which three-phase voltages (drive voltages) having different phases are applied are applied to the stator. ) And the rotor is formed integrally with the rotation output shaft 7a. The rotor is formed by a magnet. The inverter 51 receives the DC voltage Vcc supplied from the battery pack 7 and forms a three-phase voltage (drive voltage) having different phases. The formed three-phase voltage is applied to a plurality of field windings provided in the stator. Thereby, a rotating magnetic field is generated in the field winding of the stator. The rotor rotates due to the interaction between the magnetic field formed by the magnet that is the rotor and the rotating magnetic field generated in the field winding of the stator, and the rotation output shaft of the motor 7 integrated with the rotor. 7a rotates.

  In order to continuously rotate the rotor, it is necessary to sequentially switch three-phase voltages applied to the field windings of the stator according to the rotational position of the rotor. Therefore, a magnetic pole sensor 52 is attached to the brushless motor in order to detect the rotational position of the rotor.

  In FIG. 11, 56 is a resistance element for current detection. One end of the current detection resistor element 56 is connected to the inverter 51, and the other end is connected to the circuit ground voltage GND. The inverter 51 supplies a current (drive current) according to the current flowing in the field winding of the stator to one end of the current detection resistor element 56. The value of the current flowing through the rotor field winding changes in proportion to the rotational force (torque) of the rotary output shaft 7a integrated with the rotor. When the plunger 8 is moved to the top dead center side in order to compress the spring 9, the urging force generated by the spring 9 gradually increases. In order to resist the urging force of the spring 9 that gradually increases, the rotational force of the motor 7 also gradually increases, and the value of the current flowing through the field winding also increases. On the other hand, when the spring 9 is released, the required rotational force decreases, so the value of the current flowing through the field winding also decreases.

  In this manner, the drive current based on the current flowing through the field winding whose value changes according to the rotational force is converted into a detection voltage by the current detection resistor element 56. That is, it is detected as a voltage drop in the current detection resistor element 56. The detection voltage formed by the current detection resistance element 56 is supplied to the current detection circuit 57. The current detection circuit 57 amplifies the detection voltage and supplies it to the microprocessor 53 (referred to as a microcomputer in FIG. 11 and hereinafter referred to as a microcomputer).

  In FIG. 11, the control device 50 includes the microcomputer 53, the current detection circuit 57, and the current detection resistance element 56 described above. Further, the control device 50 includes a battery voltage detection circuit 63, a push switch 55, a trigger switch 54, a mode switch 58, a power switch 59, a power switch detection circuit 60, a 15-minute timer 62, a remaining nail sensor switch 64, and a detection circuit 65. The display circuit 66 and the switch 61 are provided. The control device 50 includes a storage device (not shown) that stores a program for operating the microcomputer 53. The microcomputer 53 reads a program stored in the storage device and executes a plurality of functions described below according to the program.

  The switch 61 is coupled between the power supply voltage Vcc and each circuit provided in the control device 50, for example, the microcomputer 53, the current detection circuit 57, etc., and a power switch detection circuit (described as a power supply SW detection circuit in the figure). On / off control is performed in accordance with a detection signal from 60. The power switch detection circuit 60 receives an on / off signal from a power switch (shown as power SW in the figure) 59 and an off signal from a 15-minute timer 62, and turns on the switch 61 in accordance with these on / off signal and off signal. Control off / on. Although not shown in FIG. 1, the power switch 59 is a power switch mounted on the fastener driving machine 1.

  The push switch 55 and the trigger switch 54 illustrated in FIG. 11 are the push switch 55 and the trigger switch 54 illustrated in FIGS. 1 and 2. The push switch 55 detects whether or not the nose portion 5 has been pushed to the driven member, and notifies the microcomputer 53 of the detected result. The trigger switch 54 detects the pull-in operation of the trigger 10 (FIG. 1), and notifies the microcomputer 53 when the pull-in operation of the trigger 10 is performed. Although not shown in FIG. 1, a mode switch (described as mode SW (single / ream)) 58 is provided in the fastener driving machine 1 and is a switch for selecting a driving mode. This switch is used to select whether the tool (nail) 23 is driven in a single shot or in a continuous manner. The microcomputer 53 is notified of the mode selected by the mode switch 58.

  A nail remaining amount sensor switch (denoted as a nail remaining amount sensor SW in the figure) 64 is provided so as to be engaged with the feeding member 6a (FIG. 1) at the end of the nose portion 5 side of the magazine 6 (FIG. 1). The nail remaining amount sensor switch detects the remaining amount (for example, 0 to 5 remaining amount) of the connected nail (connected fastener) 23 loaded in the magazine 6. The detection circuit 65 detects the output of the nail remaining amount sensor switch 64 and supplies the detection result to the microcomputer 53 and the display circuit 66. The battery voltage detection circuit 63 is connected to the battery pack 4, detects the voltage of the battery pack 7, and notifies the microcomputer 53.

  The 15-minute timer 62 is a counter that receives a control signal from the power switch 59 and starts counting time when the power switch 59 is turned on. The 15-minute timer 62 supplies the power switch detection circuit 60 with the 15-minute elapsed signal as an off signal when the power switch 59 is in an on state, that is, when a predetermined time (15 minutes) has elapsed since the power was turned on. The 15-minute timer 62 receives a count reset signal from the microcomputer 53. When the count reset signal is supplied, the 15-minute timer 62 resets the count value, and resumes counting the time after the reset. Although the predetermined time is 15 minutes as an example, it is not particularly limited to this time.

  Although not shown in FIG. 1, the display circuit 66 is provided in the fastener driving machine 1, receives signals from the microcomputer 53 and the detection circuit 65, and performs display. The information to be displayed includes a power display indicating that the power is turned on, a remaining battery level of the battery pack 4, a single / repetitive mode display (in the figure, single continuous display), a nail remaining amount, and the like. Here, regarding the remaining amount of the nail, the detection result is supplied from the detection circuit 65 to the display circuit 66. Thereby, the display circuit 66 displays the remaining amount of the nail as the supplied detection result as the remaining amount of the nail.

  The microcomputer 53 processes the control signals from the various switches described above, the detection results from the various detection circuits, the detection results from the current detection circuit 57, and the detection signals from the magnetic pole sensor 52 by executing a program, A control signal to the inverter 51, a display signal to the display circuit 66, a count reset signal, and the like are formed.

  For example, the microcomputer 53 grasps the voltage of the battery pack 4 based on the detection result supplied from the battery voltage detection circuit 63 and displays it on the display circuit 66 as the remaining battery level. Further, based on the control signal from the mode switch 58, the driving mode is grasped, the designated driving mode is executed, and single firing is displayed on the display circuit 66. Further, when detecting that the power switch 59 is turned on, the microcomputer 53 grasps that the power is turned on, and displays the power on the display circuit 66.

  The microcomputer 53 detects that the power switch 59 is turned on, and if the trigger switch 54, the push switch 55 or the mode switch 58 is operated within a predetermined time (15 minutes), the microcomputer 53 sets the 15-minute timer 62. In response, a count reset signal is issued. That is, when a control signal indicating that the pull-in operation of the trigger 10 has been performed within a predetermined time after the power switch 59 is turned on is supplied from the trigger switch 54 to the microcomputer 53, 15 minutes. A count reset signal is issued to the timer 62. Similarly, when a control signal indicating that the push switch 55 is brought into contact with the driven member is supplied from the push switch 55 within a predetermined time to the microcomputer 53, or a control signal indicating switching of the mode within the predetermined time. Is supplied from the mode switch 58 to the microcomputer 53, the microcomputer 53 issues a count reset signal. In response to the count reset signal, the 15-minute timer 62 resets the count value and starts counting again after the reset.

  When the ON / OFF signal from the power switch 59 indicates ON (the power switch 59 is ON), the power switch detection circuit 60 described above turns on the switch 61 and when the ON / OFF signal indicates OFF ( The power switch 59 is off), and the switch 61 is turned off. After the switch 61 is turned on, the power switch detection circuit 60 keeps the switch 61 in the on state until the on / off signal indicates that it is off, or until the off signal is supplied from the 15-minute timer 62. Thereby, it becomes possible to reduce the power consumption when the operation of the fastener driving machine 1 is not performed within a predetermined time (15 minutes), and the usable time of the fastener driving machine 1 is extended. Is possible.

  When the remaining amount of the fastener (nail) 23 in the magazine 6 decreases, a control signal indicating that the remaining amount of the fastener 23 has decreased is supplied from the detection circuit 65 to the microcomputer 53. Based on this control signal, the microcomputer 53 stops the driving of the motor 7 by the inverter 51 in order to prevent in advance the empty driving when the fasteners (nails) 23 are no longer in the magazine 6. Thereby, the motor 7 does not rotate, and it becomes possible to prevent empty driving. At this time, the microcomputer 53 instructs the display circuit 66 to display that the remaining amount of the fastener (nail) is low.

  The microcomputer 53 not only controls the inverter 51 by the control signal from each switch described above, the detection result from each detection circuit, and the detection signal from the current detection circuit 57, but also the inverter by a detection signal from the magnetic pole sensor 52. 51 is controlled.

  That is, the microcomputer 53 detects the position of the rotor in the brushless motor based on the detection signal from the magnetic pole sensor 52. A three-phase voltage supplied from the inverter 51 to the field winding so that the rotor rotates by the action between the magnetic field generated by the rotor and the rotating magnetic field generated by the field winding attached to the stator. However, on / off control of a switch element (not shown) in the inverter 51 is performed so as to switch over time based on the detected position of the rotor. The microcomputer 53 rotates or stops the rotor of the brushless motor based on the control signal from each switch, the detection result from each detection circuit, the detection signal from the current detection circuit 57, and the detection signal from the magnetic pole sensor 52. Such a three-phase voltage is generated by the inverter 51. Further, the microcomputer 53 changes the three-phase voltage generated by the inverter 51 in order to change the rotation speed of the rotor based on the supplied control signal, detection result, and detection signal. Etc. are changed.

<Operation of Control Device 50>
12A to 12F are timing charts showing the operation of the fastener driving device 1 by the control device 50. FIG. Next, the operations of the fastener driving device 1 and the microcomputer 53 will be described with reference to FIGS.

  12, (A) is the output waveform of the trigger switch 54 (trigger SW), (B) is the output waveform of the push switch 55 (push SW), (C) is the rotation amount (drum rotation angle) of the drum 13, ( D) shows the position of the plunger 8 (plunger position). In FIG. 12, (E) shows the current (motor current) flowing through the motor 7, and (F) shows the rotation amount of the motor 7 (motor rotation amount). In FIGS. 12A to 12F, the horizontal axis represents time.

  At time t0 in FIG. 12, the trigger 10 is pulled. As a result, the trigger switch 54 forms an output signal that changes from off to on at time t0. The time before time t0 is the state before driving. This state before driving is the initial state described above. That is, the drum 13 of the spring compression drive unit 81 is stopped in a state where it is rotated about 200 degrees from the reference state shown in FIG. 7 (the rotation angle of the drum 13 is about 0 degrees) ((C) of FIG. 12). ). Since the drum 13 is rotated by about 200 degrees and stopped, the plunger 8 stops not at the bottom dead center Pd but at a position close to the top dead center Pm as shown in FIG. doing.

  Next, at time t1, the push switch 55 is brought into contact with the driven member. As a result, the push switch 55 supplies the microcomputer 53 with an output signal that changes from off to on at time t1. The microcomputer 53 in the control device 50 detects the ON state output signal from the trigger switch 54 and the ON state output signal from the push switch 55 and causes the inverter 51 to start driving the motor 7. In the motor 7, the rotation of the rotor starts by being driven by the inverter 51. As described above, the rotation of the rotor in the motor 7 is performed so that the microcomputer 53 detects the position of the rotor based on the detection signal from the magnetic pole sensor 52 and generates an appropriate rotating magnetic field. This is performed under the control of 53.

  When the motor 7 rotates, the rotational force (driving force) of the rotation output shaft 7 a is transmitted to the drum 13 of the spring compression drive unit 81 via the speed reduction mechanism unit 80. By this transmission, the drum 13 in the spring compression drive unit 81 rotates in the normal rotation direction A and winds up the wire 16. Since the drum 13 rotates in the normal rotation direction A, the rotation amount (rotation angle) increases from the initial drum rotation position as shown in FIG. 12C (time t1). When the wire 16 is wound up, the plunger 8 coupled to the wire 16 moves from the initial position to the top dead center Pm side as shown in FIG. Since the plunger 8 is pulled up toward the top dead center Pm, the spring 9 is compressed accordingly.

  As the motor 7 rotates from time t1, the rotation angle of the drum 13 gradually increases and reaches a predetermined rotation angle (rotation position), as described above, the power transmission pin 17 in the spring compression drive unit 81 as described above. And the hook portion 22a are disengaged, and the drum 13 can rotate in the reverse direction.

  In this embodiment, the predetermined rotation position (rotation angle) described above is a predetermined rotation angle exceeding about 270 degrees. Assuming that the rotation angle of the drum 13 that has started rotating from time t1 has reached a predetermined rotation angle that exceeds the predetermined rotation angle of about 270 degrees at time t2, the plunger 8 is driven close to the top dead center Pm. It will move to the start position at time t2. At time t2, the engagement between the power transmission pin 17 driven by the motor 7 and the hook portion 22a integrated with the drum 13 is released. When the engagement is released, the drum 13 can rotate freely with respect to the rotating shaft 19 without receiving the driving force of the motor 7. That is, the drum 13 is separated from the rotation output shaft 19 driven by the motor 7 by the clutch function in the spring compression drive unit 81. Since the time from time t1 to time t2 affects the feeling at the time of driving, it is desirable that the time be 200 ms or less. In this embodiment, this time is set to 100 ms or less, for example.

  At time t2, when the drum 13 is rotated free, the plunger 8 to which the urging force is applied by the compressed spring 9 is released, and the plunger 8 and the blade coupled thereto by the urging force of the compressed spring 9 are released. 8a moves to the bottom dead center Pd side. By this movement toward the bottom dead center, the blade 8a strikes the fastener (nail) 23, and the fastener 23 is driven into the driven member. The position of the plunger 8 moves to the bottom dead center side as shown in FIG. 12D at time t2. The movement of the plunger 8 is transmitted to the drum 13 through the wire 16, and the drum 13 rotates in the reverse rotation direction B. The rotation position of the drum 13 is shown in FIG. Like, return to 0 degrees. That is, the drum 13 returns to the reference state shown in FIG. 7, and the power transmission pin 17 driven by the motor 7 and the hook portion 22a integrated with the drum 13 are engaged again.

  In this embodiment, the motor 7 starts rotating from time t1, and continues rotating even when the rotational position of the drum 13 returns to about 0 degrees at time t2. At time t2, since the drum 13 in the spring compression drive unit 81 is in the reference state shown in FIG. 7, the gap between the power transmission pin 17 driven by the motor 7 and the hook part 22a integrated with the drum 13 is between. Re-engage. Therefore, when the motor 7 rotates, the drum 13 rotates in the normal rotation direction A, and the wire 16 is wound around the drum 13. When the wire 16 is wound up, the plunger 8 moves to the top dead center side, and the spring 9 is compressed.

  The magnetic pole sensor 52 outputs a detection signal every time a predetermined position of the rotor is detected. Therefore, by integrating the detection signal output from the magnetic pole sensor 52, the number of rotations (rotation amount) of the rotor of the motor 7 (rotation output shaft of the motor 7) can be grasped. In this embodiment, the output of the magnetic pole sensor 52, that is, the detection signal is supplied to the microcomputer 53. The microcomputer 53 rotates the motor 7 and executes a calculation for integrating the detection signal supplied from the magnetic pole sensor 52 to obtain the rotation amount of the motor 7. The change in the rotation amount of the motor 7 obtained by this calculation is shown in FIG. During the period in which the power transmission pin 17 driven by the motor 7 and the hook portion 22a integrated with the drum 13 are engaged, the rotation position (rotation angle) of the drum 13 and the rotation amount of the motor 7 Are proportional. Further, the position of the plunger 8 depends on the rotational position of the drum 13. Therefore, during the period in which the power transmission pin 17 and the hook portion 22a are engaged, the rotational position of the drum and the position of the plunger 8 can be obtained from the rotation amount of the motor 7.

  Although not particularly limited, in this embodiment, the microcomputer 53 calculates the rotation amount of the motor 7 from the time t1 when the motor 7 starts to rotate. In order to grasp the recompression of the spring 9 performed for the next driving cycle, the microcomputer 53 starts detecting the rotation amount of the motor 7 at time t2 when the spring 9 is released. When the rotation amount of the motor reaches a predetermined value Pt from the value at time t2, the rotation of the motor 7 is stopped. That is, the detection signal from the magnetic pole sensor 52 is integrated from time t1, the rotation amount of the motor 7 is calculated, and detection of the rotation amount using the calculated rotation amount is started from time t2. The detection of the rotation amount is a determination as to whether or not the rotation amount of the motor 7 calculated by the integration operation has reached a predetermined value Pt (second value) from a value (predetermined value) at time t2. The amount of rotation of the motor 7 at time t2 corresponds to the amount of rotation when the spring compression drive unit 81 releases the spring 9 in the next driving cycle.

  When it is determined that the predetermined value Pt has been reached as a result of the determination, the microcomputer 53 supplies a control signal for supplying a three-phase voltage for stopping the motor 7 to the inverter 51. In this case, the predetermined value Pt can be obtained, for example, from the rotation amount (about 200 degrees) of the drum 13 in the initial state and the reduction gear ratio. Further, the predetermined value Pt may be obtained by trial. When the rotation amount of the motor 7 reaches a predetermined value Pt, the drum 13 and the plunger 13 have reached the initial position by stopping the motor 7. In this way, the position of the plunger 13 can be stopped at a desired position with a relatively simple configuration.

  Even if the motor 7 is stopped, the rotation output shaft 7 a of the motor 7 does not rotate in the reverse rotation direction B by the one-way clutch 24. Therefore, the rotational position of the drum 13 is maintained, and the position of the plunger 13 is also maintained. Particularly in this embodiment, the magnetic pole sensor 52 provided to rotate the rotor of the motor 7 is also used to detect the amount of rotation of the motor 7, so that an increase in the number of components is suppressed. It is also possible.

  In this embodiment, in preparation for the next driving cycle, the drum 13 is previously stopped at a predetermined position, and the position is maintained until the next driving cycle. In the next driving cycle, the drum 13 is further rotated in the forward rotation direction A from this predetermined position, and moved to a driving start position (a predetermined value with a rotation amount exceeding about 270 degrees). In the embodiment, the drum 13 can be accurately rotated to a predetermined position in preparation for the next driving cycle. Therefore, in the next driving cycle, the drum 13 can be rotated in advance to a position close to the driving start position at time t2 when the plunger 8 is released. As a result, the time until the actual driving for the driving operation in the next driving cycle can be shortened, and the driving feeling can be improved. Further, in this case, since the position of the drum can be accurately controlled, it is possible to prevent two erroneous drivings from occurring in one driving operation.

  In the embodiment, since a brushless motor is used, the efficiency of the motor can be improved, and the number of fasteners that can be driven by one charge can be increased. Furthermore, it is possible to delete a switch such as a driving detection switch for detecting driving. As a result, it is possible to relax the restriction on the installation location, which has been taken into consideration when installing a driving detection switch or the like. Further, since the driving detection switch and the like can be deleted, the cost can be reduced.

  In this embodiment, the rotation amount of the motor 7 is calculated from when the motor 7 starts to rotate (time t1). Since the rotation angle of the drum 13 and the rotation amount of the motor 7 are proportional, the motor corresponding to the rotation angle of the drum 13 (a predetermined rotation angle exceeding about 270 degrees) when the spring 9 is released (time t2). When the rotation amount (first value) of 7 is obtained, the spring compression drive unit 81 can also consider that the spring is released when the rotation amount of the motor 7 reaches this rotation amount (first value). It is.

  In this embodiment, when the drum 13 is rotated again, the rotational speed of the drum 13 may be changed in multiple stages. In this case, the rotation speed of the motor 7 is changed in order to change the rotation speed of the drum 13 in multiple stages. Although not particularly limited, when the drum 13 is rotated again and the rotational position of the drum 13 reaches a position (for example, about 150 degrees) smaller than the initial position (about 200 degrees), the rotational speed of the motor 7 is reduced. And the rotational speed of the drum 13 is reduced. Thereafter, when the rotational position of the drum 13 reaches the initial position (about 200 degrees), the motor 7 is stopped. In this manner, the rotational position of the drum 13 can be controlled more accurately by stopping after the rotational speed of the drum is decelerated. By controlling the rotational position more accurately, the position of the plunger 8 can be controlled more accurately.

  During the period in which the drum 13 is rotated again, the hook portion 22a and the power transmission pin 17 are re-engaged, so that the rotational position of the drum 13 is proportional to the rotation amount of the motor 7. Therefore, the rotation amount (deceleration rotation amount) of the motor 7 corresponding to the rotation position of the drum 13 when the rotation of the drum 13 is decelerated is obtained in advance. The microcomputer 53 integrates the detection signal of the magnetic pole sensor 52, and determines whether or not the rotation amount of the motor 7 calculated by this integration has reached the deceleration rotation amount. When the microcomputer 53 determines that the rotation amount of the motor 7 has reached the deceleration rotation amount, the microcomputer 53 controls the inverter 51 so as to reduce the rotation speed of the motor 7. As a result, the rotational speed of the drum 13 can be changed in multiple stages. The deceleration rotation amount may be a value smaller than the rotation amount of the motor 7 corresponding to the initial position of the drum 13. Moreover, you may make it set arbitrary plural numbers of deceleration rotation amount instead of one piece.

(Embodiment 2)
In the second embodiment, when detecting the rotation amount of the motor 7, a configuration suitable for determining the timing for starting the detection is shown. In the second embodiment, a change is added to the above-described first embodiment. In the following, parts different from the first embodiment will be mainly described with reference to FIGS.

  As described in the first embodiment, the motor 7 is driven by the inverter 51 from time t1 in FIG. That is, at time t1, the motor 7 changes from a stopped state to a rotating state. In order to rotate the motor 7 in a stopped state, a large inrush current is supplied from the inverter 51 to the field winding of the motor 7 at time t1. As described with reference to FIG. 11, the drive current based on the current flowing through the field winding is converted into a voltage by the current detection resistor element 56, amplified by the current detection circuit 57, and supplied to the microcomputer 53. The The output of the current detection circuit 57 supplied to the microcomputer 53 is shown as a motor current in FIG.

  Since a large value inrush current flows in the field winding at time t1, the motor current supplied from the current detection circuit 57 to the microcomputer 53 is at time t1, as shown in FIG. It is a big value. After time t1, the value of the motor current gradually decreases as the motor 7 rotates and accelerates. However, in order to compress the spring 9, the drag generated by the compressing spring 9 gradually increases. In order to counter the gradually increasing drag, the torque of the motor 7 also gradually increases. In order to increase the torque, the value of the drive current flowing through the field winding also increases. As a result, the value of the motor current from time t1 to time t2 in FIG. 12 once decreases and then increases.

  When the rotation of the drum 13 becomes free at time t2, the drag generated by the spring 9 is reduced and the torque required for the motor 7 is also reduced, so that the motor current is also reduced. Therefore, the motor current changes so as to have a maximum value at the time (time t2) when the engagement between the power transmission pin 17 driven by the motor 7 and the hook portion 22a integrated with the drum 13 is released. do. In other words, the motor current has such a characteristic that it has a maximum value when the plunger 8 is positioned near the top dead center (position for starting driving).

  Even after time t2, the inverter is driven by the inverter 51 so that the motor 7 continues to rotate. That is, even after the fastener (nail) 23 is driven, the inverter 51 is driven so that the motor 7 continues to rotate. Therefore, the power transmission pin 17 and the hook portion 22a of the spring compression drive unit 81 are re-engaged, and the rotation output shaft 19 that transmits the driving force of the motor 7 is mechanically engaged with the drum 13 again. Since the motor 7 continues to rotate, the drum 13 rotates in the normal rotation direction A, which is the direction in which the wire 16 is wound up, and the spring 9 is recompressed. For this reason, the motor current once decreases from time t2 to time t3, and then starts increasing again to resist the drag of the spring 9.

  In this embodiment, the amount of rotation of the motor 7 is detected after the power transmission pin 17 and the hook portion 22a of the spring compression drive portion 81 are re-engaged and the drum 13 reaches the reference state shown in FIG. Is done. The time (timing) when the drum 13 reaches the reference state is detected as the time when the motor current increases and reaches the maximum value. That is, the detection of the rotation amount of the motor 7 is started from time t2 when the value of the motor current increases and reaches the maximum value. When the detected rotation amount reaches a predetermined value Pt from the value at the time t2 when the detection is started (time t3), the driving of the motor 7 is stopped. In this way, the motor 7 can be stopped at a timing when the drum 13 reaches a predetermined rotational position (about 200 degrees) from a rotational position (about 0 degrees) in the reference state.

  The amount of rotation of the motor 7 is calculated by integrating the detection signal from the magnetic pole sensor 52 as described in the first embodiment. That is, the microcomputer 53 detects the timing when the motor current becomes maximum, and starts the integration calculation of the detection signal from the magnetic pole sensor 52 at the detected timing. It is determined whether or not the rotation amount of the motor 7 calculated by the integration operation that has started has reached a predetermined value Pm, and the microcomputer 53 determines that the motor 7 Instruct to stop rotation.

  In FIG. 12, the rotation amount of the motor 7 is shown as reaching a predetermined value Pt at time t3. Therefore, at time t3, the rotation drive of the motor 7 by the inverter 51 is stopped, and the rotation of the motor 7 is stopped. Here, in order to rotate the drum 13 from the reference state (about 0 degrees) to the vicinity of the initial state (about 200 degrees) and compress the spring 9, a value (amount) calculated by 200 degrees / 360 degrees × reduction gear ratio. ) Is a predetermined value Pm, and when the rotation amount of the motor 7 reaches the predetermined value Pm obtained by this calculation, the motor 7 is stopped. In this way, when the rotation amount of the motor 7 reaches the predetermined value Pt, the rotation of the motor 7 is stopped, whereby the winding amount of the wire 16 by the drum 13, in other words, the position of the plunger 8 is changed to a desired position. Can be reached.

  For example, the reduction ratio between the rotation output shaft 7a of the motor 7 and the rotation shaft 19 of the drum 13 (the rotation output shaft of the reduction mechanism 80) is 150 to 300 as described above. Here, the reduction ratio is the product of the pulley ratio (the ratio between the first pulley 14 and the second pulley 15) and the reduction gear ratio of the planetary gear 11. In this example, the pulley ratio is, for example, about 1.5, and the reduction gear ratio of the planetary gear is, for example, about 100 to 200. Therefore, the reduction ratio is 150 to 300 as described above. On the other hand, the product of the diameter of the drum groove 13 b of the drum 13, the rotation position (rotation angle) of the drum 13, and the circumferential ratio is equal to the winding amount of the wire 16. Here, the rotation angle of the drum 13 is equal to the rotation angle of the rotation output shaft 19. Accordingly, the rotation amount of the motor 7 corresponds to a value (amount) obtained by multiplying the quotient obtained by dividing the winding amount by the wire 16 by the product of the diameter of the drum groove portion 13b and the circumferential ratio and the reduction ratio. .

  That is, the amount of winding by the wire 16 is proportional to the amount of rotation of the motor 7, and the amount of winding by the wire 16 can be accurately controlled by controlling the amount of rotation of the motor 7. Therefore, when the rotation amount of the motor 7 reaches the predetermined value Pt, the motor 7 is stopped, so that the winding amount of the wire 16 can be set to a desired value and the plunger 8 can be stopped at a desired position. Become.

  When the motor 7 is stopped, the drum 13 tends to be rotated in the reverse rotation direction B by the urging force of the spring 9, but the drum 8 is pulled in the state where the plunger 8 is pulled by the reverse rotation preventing function of the one-way clutch 24. 13 stops and the state is maintained. As a result, the drum 13 rotates from the rotation angle in the reference state (about 0 degrees) to the rotation angle in the initial state (about 200 degrees), and the rotation angle is maintained. Thereby, the plunger 8 is also stopped and maintained at a predetermined position which is an initial state. In this initial state, the driving cycle ends, and the next driving cycle starts from this initial state maintained.

  As described above, the motor 7 is stopped at time t3. As a result, the value of the motor current becomes substantially zero at time t3 as shown in FIG. On the other hand, as shown in FIGS. 12C and 12D, the rotational angle of the drum 13 and the plunger position of the plunger 13 are slow even after the time t3 due to the rotational inertia of the drum 13 and the like. Is rising. The predetermined value Pt, which is the rotation amount for stopping the motor 7, is preferably determined in consideration of the rotational inertia of the drum 13 or the like.

  According to the second embodiment, the rotational position of the drum 13 can be detected by calculating the rotation amount of the motor 7, and the drum 13 and the plunger 8 can be stopped at a preset position. The positions of the drum 13 and the plunger 8 can be accurately controlled. In this case, since it is possible to calculate and control the amount of rotation of the motor 7 using the magnetic pole sensor 52 and the microcomputer 53, it is possible to perform accurate control while suppressing an increase in additional parts.

  In the second embodiment, the rotation amount of the motor 7 is obtained from the timing of driving the fastener 23. That is, the amount of rotation of the motor 7 is detected from the time when the engagement between the power transmission pin 17 and the hook portion 22a is released and the plunger 8 moves to the bottom dead center side (time t2 in FIG. 12). Therefore, even if the rotation position (rotation angle) of the drum 13 stopped before performing the driving operation greatly deviates from the value set as the initial state (in the example, about 200 degrees), it is for the next driving cycle. In the rotation of the drum 13, it is possible to accurately rotate the drum 13 so as to match the value set as the initial state. For example, even if the position at which the drum 13 is stopped fluctuates due to fluctuations in rotational speed or mechanical loss due to fluctuations in the power supply voltage Vcc from the battery pack 4, the drum 13 provided for the next driving cycle is changed. In this rotation, it is possible to stop at the initial position.

  In the second embodiment, the microcomputer 53 may calculate the rotation amount of the motor 7 between time t1 and time t2. The rotation amount of the motor 7 from time t1 to time t2 corresponds to the rotation amount from the initial state of the drum 13 (about 200 degrees) to the state in which the drum 13 is released (rotation angle exceeding about 270 degrees). That is, it corresponds to the rotation amount of the motor 7 from the initial state to driving. On the other hand, in the previous driving cycle, since the rotation amount of the motor 7 after driving (time t2) can be grasped, the grasping rotation amount of the motor 7 and the rotation of the motor 7 from time t1 to time t2 are grasped. Depending on the amount, the predetermined amount of rotation in the current driving cycle can be corrected.

  That is, if the sum of the rotation amount of the motor from the initial state to driving in the current driving operation and the rotation amount of the motor 7 after driving in the previous driving cycle is the same as the reduction gear ratio, the drum 13 is It will be rotated. Therefore, in this case, there is no need to change the predetermined rotation amount in the current driving cycle. On the other hand, when the sum of the rotation amounts described above is smaller than the reduction gear ratio, for example, the value of the predetermined rotation amount after the current driving is increased so that the position (rotation amount) of the drum 13 in the initial state is increased. Correct. By this correction, the drum 13 can reach an appropriate initial position at the next driving operation. As a result, at the time of the next driving operation, it is possible to set the time from when the push switch is turned on to when the driving is actually performed to a desired time, and to prevent the driving feeling from deteriorating. .

  Next, the operation of the microcomputer 53 in the second embodiment will be described with reference to FIG. The microcomputer 53 performs each step shown in FIG. 13 according to the program.

  First, in step S1, processing is started. In step S2, it is determined whether or not driving is permitted. In step S <b> 2, for example, it is determined whether or not an on-state control signal is supplied from the push switch 55. If it indicates an off state, the process returns to step S2, and step S2 is repeated until the control signal is turned on. If it is determined in step S2 that the switch is on, step S3 is executed next.

  In step S3, the microcomputer 53 receives a detection signal from the magnetic pole sensor 52 to rotate the motor 7, and supplies a control signal to the inverter 51 while determining the position of the rotor. Thereby, the inverter 51 applies a three-phase voltage to the motor 7 so as to rotate the motor 7 in the positive rotation direction A. The microcomputer 53 continues to supply a control signal for rotating the motor 7 to the inverter 51 until the motor 7 is stopped in step S9 described later. In step S3, the microcomputer 53 takes in the detection voltage from the current detection circuit 57 and starts detecting the motor current ((E) in FIG. 12) based on the value of the detection voltage. (In FIG. 13, step S2 is described as motor rotation start / current detection start).

  In step S4, the microcomputer 53 calculates the amount of change with respect to time for the motor current. The amount of change is obtained by calculating the first derivative and the second derivative with respect to time for the value of the motor current. Here, the value obtained by calculating the first derivative with respect to time is the current change amount, and the value obtained by calculating the second derivative with respect to time is the second derivative value of the motor current. And In FIG. 13, step S4 is described as current change calculation / current second derivative calculation.

  In step S5, it is determined whether or not the current change amount obtained in step S4 is 0 (current change amount = 0?). That is, if the current change amount of the motor current is 0, it is determined that the motor current is at the maximum value in the upward direction or the downward direction, and then Step S6 is executed. On the other hand, if the amount of change in current is not 0, it is determined that the maximum value has not been reached, and the process returns to step S4, and the first and second derivatives with respect to the motor current are calculated.

  In step S6, it is determined whether or not the current secondary differential value obtained in step S4 is smaller than 0 (current secondary differential value <0?). Since the current second derivative value is a second derivative value, when it is smaller than 0, the motor current value changes in the increasing direction. Therefore, in this case, the motor current has a maximum value in the upward direction. On the other hand, when the current secondary differential value is 0 or more, the maximum value occurs when the motor current changes in the decreasing direction. As understood from FIG. 12E, when the motor current is in the increasing direction, the timing at which the maximum value is reached represents the timing of driving. Therefore, when the current secondary differential value is 0 or more, the process returns to step S4, and in step S4, the primary differential and the secondary differential are calculated. On the other hand, when the current secondary differential value is smaller than 0, step S7 is executed next.

  In step S7, calculation of the rotation amount of the motor is started. Calculation of the rotation amount of the motor is obtained by integrating the detection signal from the magnetic pole sensor 52. That is, in step S6, the integration calculation of the detection signal is started and the calculation of the rotation amount of the motor 7 is started from the timing when the motor current is determined to be the maximum value in the upward direction. It is determined in step S8 whether or not the rotation amount calculated by calculation has reached a predetermined rotation amount (value) Pm (predetermined rotation amount?). When the rotation amount of the motor 7 obtained by the calculation does not reach the predetermined rotation amount, the rotation amount is continuously calculated (step S8). That is, in step S8, the detection signal from the magnetic pole sensor 52 is captured until the value obtained by integrating the detection signal from the magnetic pole sensor 52 reaches a value corresponding to the predetermined rotation amount, and the calculation is performed.

  If it is determined in step S8 that the rotation amount of the motor 7 calculated by the calculation has reached the predetermined rotation amount, step S9 is performed next. In step S <b> 9, the microcomputer 53 supplies a control signal for stopping the rotation of the motor 7 to the inverter 51. Thereby, the motor 7 stops rotating.

  After the motor 7 is stopped, step S10 is performed. In step S10, it is determined whether or not driving is permitted. In step S10, for example, the state of the trigger switch 54 is determined. If the trigger switch 54 is on, step S2 is executed next. If the trigger switch 54 is off, step S10 is executed until the trigger switch 54 is turned on.

  In step S2 or S10, the detection signal from the detection circuit 65 may be used as a determination condition for permission to drive. When a detection signal indicating that the remaining amount of the fastener 23 is small is supplied from the detection circuit 65, the driving permission may be NO. In step S10, the rotation amount of the motor calculated in step S8 is reset. Alternatively, in step S7, before starting the motor rotation amount calculation, the previous motor rotation amount is reset.

  Thus, the timing of the maximum value generated when the motor current is changing in the increasing direction is determined in steps S4 to S6. Calculation of the rotation amount of the motor 7 is started from the timing at which the determined maximum value is generated (time t2). When the rotation amount of the motor 7 reaches the predetermined rotation amount in step S8 (time t3), the motor The rotation of 7 is stopped.

  Also in the second embodiment, when the drum 13 is rotated again after driving, the rotational speed of the drum 13 may be changed in multiple stages. In this case, for example, in step S8, it is determined whether or not the rotation amount of the motor 7 has reached a first rotation amount (deceleration rotation amount) that is a rotation amount smaller than a predetermined rotation amount, and the first rotation When it is determined that the amount has been reached, the rotational speed of the motor 7 is decelerated from high speed to low speed. Thereafter, when the rotation amount of the motor 7 reaches a predetermined rotation amount, the motor 7 is stopped. This can be achieved by changing the control signal supplied from the microcomputer 53 to the inverter 51 to control the motor 7 from high speed rotation, low speed rotation, and stop from the inverter 51.

  In this way, when the plunger 8 moves to the bottom dead center side and then is moved again to a predetermined position on the top dead center side by the driving force of the motor 7, the rotational speed of the motor 7 is reduced to a predetermined value or less. Then, the motor 7 can be stopped. Thereby, after the driving is completed, as a preparation for the next driving cycle, it is possible to control the stop position of the plunger 8 to a predetermined position as close as possible to the driving start position. That is, as a preparation for the next driving cycle, the stop position of the plunger 8 can be controlled more finely. As a result, at the end of the driving cycle, the driving spring 9 can be surely compressed so as to have a predetermined driving energy and can be ended. Therefore, the compression time of the spring 9 in the next driving cycle can be shortened, the entire driving time can be shortened, and the driving feeling can be improved.

  The stop position of the plunger 8 after the completion of driving is preferably set so that the lower end of the blade 8a is within the range of the fastener 23 loaded in the magazine 6 and near the upper end of the fastener 23. Thereby, since the blade 8a is located in the injection portion passage 5a of the nose 5, it is possible to prevent the fastener 23 for the next driving from being supplied into the injection portion passage 5a, and to The time required for driving can be shortened.

  In the second embodiment, the calculation for calculating the rotation amount (number of rotations) of the motor is started from the timing when the motor current shows the maximum value. Therefore, when the amount of rotation of the motor between time t1 and time t2 is not calculated, it is possible to reduce the number of calculations and reduce power consumption.

  FIG. 14 is a schematic diagram illustrating a configuration of a brushless motor. As described in FIG. 11, in this embodiment, the rotor is constituted by a magnet, and the field winding is provided on the stator. In the brushless motor shown in FIG. 14, the rotor is composed of four magnets 7 c to 7 f. The stator has six poles U1, V1, W1, U2, V2, and W2, and windings cu1, cv1, cw1, cu2, cv2, and cw2 are respectively provided. In addition, magnetic pole sensors 52a, 52b and 52c are provided in the brushless motor.

  Three-phase voltages (U-phase, V-phase, W-phase) are applied from the inverter 51 to the windings cu1, cv1, cw1, cu2, cv2, cw2 provided on the stator, and the stator is converted to the three-phase voltage. A corresponding magnetic field is generated. The rotor 7b rotates due to the action of the magnetic field generated in the stator and the magnetic field of the rotor 7b (magnets 7c to 7f).

  The magnetic pole sensors 52 a to 52 c form detection signals when the magnets 7 c to 7 f of the rotor 7 b pass and supply the detection signals to the microcomputer 53. Therefore, based on the detection signal from each of the magnetic pole sensors 52a to 52c, the microcomputer 53 grasps the position of the rotor and controls the phase of the three-phase voltage applied from the inverter 51 to the brushless motor, thereby rotating the rotor. It drives so that 7b may rotate. Further, by integrating the detection signals from each of the magnetic pole sensors 52a to 52c, an integrated value corresponding to the rotation speed of the rotor 7b can be obtained as the rotation amount. In addition, the value of the current flowing through the field winding is a value corresponding to the drag in order to generate a rotational torque against the drag of the spring 9 compressed by the brushless motor. Since a current corresponding to the drive current flowing through the field winding is supplied to the current detection resistance element 56, a voltage drop corresponding to the current corresponding to the drag force of the spring 9 is generated in the current detection resistance element 56. The rotor 7b is integrated with the rotation output shaft 7a of the motor 7.

  In the first embodiment described above, the number of rotations from when the motor 7 is rotated (time t1) is integrated by integrating the detection signal of the magnetic pole sensor 52 from that time (time t1). Calculated as a quantity. Further, in the second embodiment, as can be understood from FIG. 13, the rotational speed of the motor 7 from the timing of driving (time t2) is the magnetic pole sensor 52 (52a to 52a ~) from that time (time t2). The rotation amount of the motor 7 is calculated by integrating the detection signal 52c). As described above, the calculation of the rotation amount of the motor 7 may be performed when the rotation of the motor 7 is started, or may be started from the timing of driving.

  In the description of FIG. 13, it has been described that the determination as to whether or not the current change amount has become 0 is performed in step S <b> 5. When the microcomputer 53 detects the motor current, for example, the output of the current detection circuit 57 is sampled and the value is determined as the motor current. Depending on the timing at which the output of the current detection circuit 57 is sampled, it is conceivable that the value when the motor current becomes 0 cannot be sampled. In this case, the time when the amount of change in the motor current changes from positive to negative may be determined as the timing at which the maximum value occurs.

  In the above-described embodiments, the case where the trigger switch and the push switch are applied as the operation switches has been described, but other operation switches can be applied. Further, in the embodiment, the case where the trigger switch is operated with priority over the push switch has been described, but the same configuration can be made even when the push switch is prioritized. Furthermore, the normally-off type switch that is normally in the off state is used as the trigger switch and the push switch, but a normally-on type switch that is normally in the on state may be applied.

  In addition, although the trigger switch 54 is operated and current is supplied to the motor 7, a situation where the nail clogging occurs and the plunger 8 cannot be pushed up may occur. If the rotation amount of the motor 7 is not detected for a predetermined time after the trigger switch 54 is operated using the detection of the rotation amount, it is determined that an abnormality such as a nail clogging has occurred and the supply of current to the motor 7 is stopped. It is desirable.

  Although the invention made by the inventor has been specifically described based on the above embodiment, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention.

DESCRIPTION OF SYMBOLS 1 Fastener driving machine 2 Body housing part 2a Wall part 2b Attachment part 3 Handle housing part 4 Battery pack 5 Nose 5a Injection part channel | path 6 Magazine 6a Feeding member 7 Motor 7a Rotation output shaft 8 Plunger 8a Blade 8b Plunger plate 9 Spring DESCRIPTION OF SYMBOLS 10 Trigger 11 Planetary gear 12 Damper 13 Drum 13a Drum damper engaging part 13b Drum groove part 14 First pulley 15 Second pulley 16 Wire 17 Power transmission pin 17a Pin slide part 17b Pin hook part 18 Guide plate 18a Guide groove 16b Guide Protrusion 19 Rotation output shaft of deceleration mechanism 20 Key 21 Pin support plate 21a Pin support slide 21b Key groove 22 Drum hook 22a Hook 22b Bearing 23 Fastener (nail)
24 one-way clutch 40 belt 50 controller 51 inverter 52 magnetic pole sensor 53 microcomputer 54 trigger switch 55 push switch 56 current detection resistor 57 current detection circuit 58 single / repetitive mode switch 59 power switch 60 power switch detection circuit 61 controller power switch 62 15-minute timer 63 Battery voltage detection circuit 64 Nail remaining amount sensor switch 65 Detection circuit 66 Display circuit 80 Deceleration mechanism 81 Spring compression release mechanism

Claims (10)

A plunger having a blade for driving the fastener and movable between a bottom dead center and a top dead center;
A motor for moving the plunger from the bottom dead center to the top dead center;
A drive unit configured to drive the fastener with the blade when the plunger reaches the top dead center by rotation of the motor;
A one-way clutch that suppresses rotation of the motor so that the blade does not move when the motor is stopped so that the plunger stops between the bottom dead center and the top dead center;
A switch and a control device for instructing driving of the fastener are provided,
The control device operates the motor in response to an instruction to drive the fastener, and moves the plunger stopped between the bottom dead center and the top dead center to the top dead center. Let
The motor includes a rotational position detection sensor that detects a rotational position of a rotor of the motor,
The control device includes a processing device that receives a detection signal from the rotational position detection sensor and calculates a rotation amount of the motor based on the detection signal, and the plunger is based on the calculated rotation amount. A fastener driving machine in which the motor is stopped so as to stop between the bottom dead center and the top dead center . 2. The fastener hitting device according to claim 1, wherein the control device changes the rotation speed of the motor when the rotation amount of the motor reaches a predetermined rotation amount smaller than a rotation amount at which the motor stops. Embedded machine. Comprising a magazine loaded with the fasteners;
The said stop position of the said plunger is in the range of the said fastener with which the lower end of the said blade is loaded in the said magazine, Comprising: It is near the upper end of the said fastener. Fastener driving machine. The motor includes a stator and a rotor connected to the drive unit, and the rotor is rotated by a drive voltage, and a current flowing through the motor is determined according to a drag generated when the plunger is moved. A motor whose value changes,
The control device includes a detection circuit that detects a current flowing through the motor, and when the maximum value is generated in the current detected by the detection circuit, the plunger reaches the top dead center. The fastener driving machine according to any one of claims 1 to 3 . Based on a detection signal from the rotational position detection sensor, the processing device calculates a rotation amount of the motor from a driving instruction for driving the fastener to a maximum value generated in a current flowing through the motor. Calculate
The fastener driving machine according to any one of claims 1 to 4 , wherein a rotation amount for stopping the motor is changed based on the calculated rotation amount. The drive unit is
A rotating shaft connected to the rotor of the motor and rotating;
A rotating body driven by the rotating shaft;
Comprising
The fastener driving machine according to any one of claims 1 to 5, wherein the rotating body is separated from the rotating shaft when the plunger reaches the top dead center.   The fastener driving machine according to any one of claims 1 to 6, wherein the motor is a brushless motor. A magazine that supplies fasteners to the nose,
A plunger that is movably disposed between a bottom dead center and a top dead center, and has a blade for driving the fastener supplied to the nose portion;
A brushless motor for moving the plunger from the bottom dead center to the top dead center;
When the brushless motor includes a rotating body that is driven to rotate in a predetermined rotation direction, and when the rotating body rotates, the plunger moves to the top dead center side and reaches the top dead center A drive unit for driving the fastener with the blade;
A one-way clutch that stops rotation of the rotating body when the brushless motor is stopped so that the plunger is stopped between the bottom dead center and the top dead center;
A control device for controlling the operation of the brushless motor;
Comprising
The brushless motor has a stator, a rotor, and a magnetic pole sensor that detects a rotational position of the rotor,
The control device operates the brushless motor to move the plunger from the bottom dead center to the top dead center after the fastener is driven, and based on a detection signal from the magnetic pole sensor, A fastener driving machine that calculates a rotation amount of a rotor of the brushless motor and stops the brushless motor when the rotation amount reaches a predetermined value. The fastener driving machine includes a switch for instructing driving of the fastener,
The controller is
A detection circuit for detecting a value of a current flowing through the brushless motor;
The brushless motor is operated in response to the fastener driving instruction by the switch, and the brushless motor is operated, so that the current flowing through the brushless motor is based on the detection signal output from the detection circuit. A time change amount is calculated, and based on the calculated time change amount, a time at which the rotating body reaches a rotation position corresponding to the top dead center is determined, and the rotation amount of the rotor is determined from the determined time. A controller for calculating,
The fastener driving machine according to claim 8, comprising: The controller calculates a rotation amount of the rotor of the brushless motor from the operation of the brushless motor to the determined time based on a detection signal from the magnetic pole sensor, and the calculated rotor The fastener driving machine according to claim 9 , wherein the predetermined value is changed in accordance with the amount of rotation.

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