Work machine

Abstract

The present invention improves the convenience of a work machine. A nailing machine 1A comprises: a motor 44; a striking part movable in upward and downward directions and capable of striking a nail supported by an ejection part 4 by moving downward; a coil spring 23 biasing the striking part downward; and a controller 6 capable of switching the motor 44 between an operating state in which the motor 44 outputs a driving force and a stopped state in which the motor 44 does not output a driving force. The controller 6 controls the state of the motor and the stop position of the striking part, on the basis of control amounts and information related to the striking part, or related to a moving member that moves in conjunction with the striking part.

Description

Work equipment

[0001] The present invention relates to a work machine suitable for driving fasteners such as nails and staples into mating materials such as wood and plasterboard.

[0002] Patent Document 1 discloses a nail gun, which is one of the above-mentioned work machines. The nail gun described in Patent Document 1 includes a motor, a striking unit driven by the motor to strike a nail, and a position detection sensor that detects the position of the striking unit.

[0003] The nail driver described in Patent Document 1 stops the motor based on the detection result of the position detection sensor, thereby stopping the striking part at a predetermined position.

[0004] International Publication No. 2018 / 159172

[0005] Further improvements in the convenience of work equipment are required.

[0006] a control unit that can switch the motor between an operating state in which a driving force is output and a stopped state in which no driving force is output; and a rotating unit that rotates by the driving force output from the motor. The working machine according to one embodiment includes a motor; an ejection unit that supports a stopper; a striking unit that is movable in a first direction and a second direction opposite to the first direction and that can strike the stopper supported by the ejection unit by moving in the first direction; a biasing unit that biases the striking unit in the first direction; a control unit that can switch the motor between an operating state in which a driving force is output and a stopped state in which no driving force is output; and a rotating unit that rotates by the driving force output from the motor. The striking unit is located at a first position, and when the rotating unit rotates while engaged with the rotating unit, the striking unit moves in the second direction from the first position to a second position against the biasing of the biasing unit, and the striking unit When the impact portion disengages from the rotating portion at the second position, it moves in the first direction from the second position to the third position due to the force of the force of the force unit, and when the impact portion re-engages with the rotating portion at the third position, it moves in the second direction from the third position to the first position against the force of the force unit, and when the control amount from the point at which the impact portion or a moving member that moves in conjunction with the impact portion leaves the fourth position exceeds a first predetermined amount, the control unit switches the motor to the stopped state, and the control unit performs adjustment control to adjust the stop position of the impact portion to match the first position based on first information acquired when the motor is in the operating state.

[0007] According to the present invention, a work machine with further improved convenience is realized.

[0008] FIG. 1 is a side view showing the structure of a nail driver according to a first embodiment. FIG. 2 is a schematic view showing the structure of a striking mechanism provided in the nail driver according to the first embodiment. FIG. 3 is an explanatory view showing the operation of the striking mechanism according to the first embodiment. FIG. 4 is another explanatory view showing the operation of the striking mechanism according to the first embodiment. FIG. 5 is another explanatory view showing the operation of the striking mechanism according to the first embodiment. FIG. 6 is a timing chart showing the relationship between the output change of the microswitch and the position change of the plunger under normal conditions. FIG. 7 is another timing chart showing the relationship between the output change of the microswitch and the position change of the plunger under normal conditions. FIG. 8 is a timing chart showing the relationship between the output change of the microswitch and the position change of the plunger under abnormal conditions. FIG. 9 is another timing chart showing the relationship between the output change of the microswitch and the position change of the plunger under abnormal conditions. FIG. 10 is a side view showing the structure of an electric tacker according to a second embodiment. FIG. 11 is an enlarged oblique view showing the striking mechanism provided in the electric tacker according to the second embodiment. FIG. 12 is a timing chart showing the relationship between the output change of the microswitch and the position change of the plunger under normal conditions. FIG. 13 is a timing chart showing the relationship between the output change of the microswitch and the position change of the plunger when the response time is shorter than a second predetermined amount. FIG. 14 is a timing chart showing the relationship between the output change of the microswitch and the position change of the plunger when the response time is longer than a second predetermined amount.

[0009] Hereinafter, several embodiments will be described in detail with reference to the drawings. In all drawings referred to in describing the embodiments, the same or substantially the same configurations and elements will be designated by the same reference numerals. Furthermore, as a general rule, once a configuration or element has been described, it will not be described again.

[0010] (First embodiment) <Outline of nail driver> A work machine according to this embodiment is suitable for driving fasteners such as nails and staples into mating materials such as wood, gypsum board, etc. More specifically, the work machine according to this embodiment is a nail driver that drives nails into mating materials.

[0011] 1 is a side view showing the structure of a nail driver 1A according to the present embodiment. The nail driver 1A has a housing 2, a magazine 3, an ejection unit 4, and the like.

[0012] The housing 2 has a main body 10, a handle 11, a motor housing 12, and a connecting portion 13. One longitudinal end of the handle 11 and the motor housing 12 is connected to the main body 10, and the other longitudinal end of the handle 11 and the motor housing 12 is connected to the connecting portion 13. In other words, the main body 10, the handle 11, the motor housing 12, and the connecting portion 13 are integrated.

[0013] A plurality of nails are loaded into the magazine 3. The plurality of nails loaded into the magazine 3 are supplied one by one to the ejection unit 4. The ejection unit 4 supports the nails fed from the magazine 3 so that they can be ejected.

[0014] When a predetermined operation is performed on the operating unit including the trigger lever 7 provided on the handle 11, the nail supported by the ejector 4 is struck by a striking mechanism 20 (FIG. 2) described below. As a result, the nail is ejected from the ejector 4 and driven into the target material.

[0015] <Housing> The main body 10 of the housing 2 has a generally rectangular cylindrical shape overall. Here, the longitudinal direction of the main body 10 shown in Fig. 1 is defined as the "up-down direction," and the longitudinal direction of the handle portion 11 and the motor housing portion 12 is defined as the "front-rear direction." Furthermore, the direction perpendicular to the up-down direction and the front-rear direction is defined as the "left-right direction." However, these definitions are merely provided for the convenience of explanation.

[0016] According to the above definition, the handle portion 11 is located above the motor housing portion 12 and extends rearward from the back surface of the main body portion 10. On the other hand, the motor housing portion 12 is located below the handle portion 11 and extends rearward from the back surface of the main body portion 10. Furthermore, the connecting portion 13 connects the rear end of the handle portion 11 and the rear end of the motor housing portion 12.

[0017] A battery mounting section to which the battery pack 5 can be attached and detached is provided on the rear surface of the connecting section 13. The connecting section 13 also houses a controller 6 as a control section.

[0018] In this embodiment, the downward direction corresponds to the first direction of the present invention, and the upward direction corresponds to the second direction (the direction opposite to the first direction) of the present invention.

[0019] The housing 2 is composed of two housing members made of synthetic resin such as nylon or polycarbonate. More specifically, the two housing members are butted together and fixed to form the housing 2 having a main body portion 10, a handle portion 11, a motor accommodating portion 12, and a connecting portion 13.

[0020] At least a portion of the surface of the housing 2 is covered with a resin cover. More specifically, at least a portion of the surface of the housing 2 is covered with a resin layer (elastomer layer) formed (laminated) on the housing 2 by two-layer molding (two-color molding).

[0021] <Impact Mechanism> Fig. 2 is a schematic diagram showing the structure of the impact mechanism 20 provided in the nail driver 1A. The impact mechanism 20 is comprised of a plunger 21, a driver blade 22, a coil spring 23, a counterweight 24, a gear group 25, a guide bar 26, etc., which are housed in the main body 10 (Fig. 1).

[0022] The plunger 21 and the driver blade 22 are capable of striking a nail supported by the ejection unit 4 (FIG. 1) and correspond to the striking unit of the present invention. The coil spring 23 is capable of biasing the plunger 21 and the driver blade 22 downward and corresponds to the biasing unit of the present invention.

[0023] <Plunger> The plunger 21 includes three arms (arms 31, 32, and 33) and a pin 34. The arms 31, 32, and 33 protrude rearward, and the pin 34 protrudes forward.

[0024] The pin 34 is inserted into a through hole provided at the upper end of the driver blade 22. As a result, the plunger 21 and the driver blade 22 can move together in the up and down direction.

[0025] <<Coil Spring>> The coil spring 23 is formed of a spirally wound wire. The lower end of the coil spring 23 abuts against the plunger 21, and the upper end of the coil spring 23 abuts against the counterweight 24.

[0026] <Counterweight> The counterweight 24 has a rectangular cylindrical shape, and the upper part of the coil spring 23 is inserted into the inside of the counterweight 24. As a result, the upper end of the coil spring 23 abuts against the inner surface of the bottom wall of the counterweight 24 inside the counterweight 24.

[0027] An arm 35 similar to the arm provided on the plunger 21 is provided on the rear side of the counterweight 24 .

[0028] The coil spring 23 is disposed between the plunger 21 and the counterweight 24, which are opposed to each other in the vertical direction. Therefore, when the coil spring 23 compresses, the plunger 21 and the counterweight 24 move closer to each other. On the other hand, when the coil spring 23 expands, the plunger 21 and the counterweight 24 move away from each other.

[0029] From another perspective, when the striking part (plunger 21, driver blade 22) moves downward, the counterweight 24 moves upward. On the other hand, when the striking part (plunger 21, driver blade 22) moves upward, the counterweight 24 moves downward.

[0030] That is, the striking portion (plunger 21, driver blade 22) and the counterweight 24 move in opposite directions. The up and down movements of the plunger 21, driver blade 22, and counterweight 24 will be described later.

[0031] <Gear Group> The gear group 25 includes a first gear 41, a second gear 42, and a third gear 43. The first gear 41, the second gear 42, and the third gear 43 are each supported so as to be rotatable.

[0032] The driving force output from a motor 44 (FIG. 1) is input to the gear group 25 via a gear box 45 (FIG. 1). More specifically, the driving force output from the motor 44 is input to the first gear 41 via a planetary gear type reduction mechanism housed in the gear box 45.

[0033] The first gear 41 meshes with the second gear 42, and the second gear 42 meshes with the third gear 43. In other words, the second gear 42 meshes with both the first gear 41 and the third gear 43. Therefore, when the driving force output from the motor 44 is input to the first gear 41, the first gear 41, the second gear 42, and the third gear 43 each rotate.

[0034] That is, the first gear 41, the second gear 42, and the third gear 43 are rotating parts that rotate by the driving force output from the motor 44. Cam rollers, which will be described later, are provided on the front surfaces of the first gear 41, the second gear 42, and the third gear 43.

[0035] <<Guide Bar>> The guide bar 26 is a long, thin metal member that extends in the vertical direction. Note that a similar guide bar 26 is disposed behind the guide bar 26 shown in Fig. 2. In other words, the impact mechanism 20 includes a pair of guide bars 26 that face each other in the left-right direction.

[0036] The lower end of each guide bar 26 is fixed to the bottom holder 51, and the upper end of each guide bar 26 is fixed to the top holder 52. From another perspective, the bottom holder 51 and the top holder 52 are connected by the pair of guide bars 26.

[0037] The plunger 21 is disposed between the lower end of the coil spring 23 and the bottom holder 51 , and a ring-shaped lower damper 53 is disposed between the plunger 21 and the bottom holder 51 .

[0038] The counterweight 24 is disposed between the upper end of the coil spring 23 and the top holder 52 , and a ring-shaped upper damper 54 is disposed between the counterweight 24 and the top holder 52 .

[0039] The lower damper 53 and the upper damper 54 are made of an elastic material such as rubber. The lower damper 53 receives the biasing force of the coil spring 23 and receives the plunger 21 moving downward, and prevents damage or deformation of the bottom holder 51 due to a collision of the plunger 21.

[0040] On the other hand, the upper damper 54 receives the counterweight 24 that moves upward due to the biasing force of the coil spring 23, and prevents damage or deformation of the top holder 52 due to a collision with the counterweight 24.

[0041] In the following description, the lower damper 53 may be referred to as the "plunger damper 53" and the upper damper 54 may be referred to as the "weight damper 54."

[0042] A guide shaft 23a that passes through the coil spring 23 is provided between a pair of opposing guide bars 26. The lower part of the guide shaft 23a passes through the plunger 21 and plunger damper 53 and is connected to the bottom holder 51. The upper part of the guide shaft 23a passes through the counterweight 24 and weight damper 54 and is connected to the top holder 52.

[0043] The guide shaft 23a guides the expansion and contraction of the coil spring 23. At the same time, the guide shaft 23a guides the up and down movement of the plunger 21 and the counterweight 24.

[0044] From another perspective, the guide bar 26, the guide shaft 23a, the bottom holder 51, and the top holder 52 form a frame that supports the plunger 21 and the counterweight 24 so that they can move up and down.

[0045] <Operation of the Impact Mechanism> Figures 3, 4, and 5 are explanatory diagrams showing the operation of the impact mechanism 20. The plunger 21 and the counterweight 24 shown in Figures 3, 4, and 5 are located at different positions in the vertical direction.

[0046] More specifically, the plunger 21 and counterweight 24 shown in Fig. 3 are in a first position (standby position), the plunger 21 and counterweight 24 shown in Fig. 4 are in a second position (top dead center), and the plunger 21 and counterweight 24 shown in Fig. 5 are in a third position (bottom dead center).

[0047] It should be noted that each of the first position (standby position), second position (top dead center), and third position (bottom dead center) is a position range having a certain width, and is not limited to a single point.

[0048] As described above, cam rollers are provided on the front surfaces of the first gear 41, the second gear 42, and the third gear 43. More specifically, cam roller 41a is provided on the front surface of the first gear 41. Cam rollers 42a and 42b are provided on the front surface of the second gear 42. Cam rollers 43a and 43b are provided on the front surface of the third gear 43.

[0049] 3, when the plunger 21 is in the standby position, the cam roller 42b of the second gear 42 engages with the arm 33 of the plunger 21 from below. When the counterweight 24 is in the standby position, the cam roller 43b of the third gear 43 engages with the arm 35 of the counterweight 24 from above.

[0050] Furthermore, the stopper 27, which is rotatably mounted on the guide bar 26, has begun to engage with the counterweight 24, which is located in the standby position. However, the stopper 27 has not yet completely engaged with the counterweight 24. Note that the stopper 27 is not shown in Figure 2.

[0051] 1 can switch the state of the motor 44 based on predetermined conditions and information. For example, when the plunger 21 and the counterweight 24 are in the standby position and a predetermined operation is performed on the operation unit including the trigger lever 7, the controller 6 switches the motor 44 from a stopped state to an operating state. More specifically, the controller 6 supplies power from the battery pack 5 to the motor 44, switching the motor 44 from a stopped state in which it does not output driving force to an operating state in which it outputs driving force.

[0052] When the motor 44 is switched to an operating state, a driving force is input to the first gear 41 shown in Fig. 3. Then, the first gear 41 rotates counterclockwise, the second gear 42 rotates clockwise, and the third gear 43 rotates counterclockwise.

[0053] When the second gear 42 rotates clockwise, the plunger 21 is pushed up by the cam roller 42b of the second gear 42, which is engaged with the arm 33 of the plunger 21. As a result, the plunger 21 moves upward against the bias of the coil spring 23. In other words, the plunger 21 moves up while compressing the coil spring 23.

[0054] On the other hand, when the third gear 43 rotates counterclockwise, the cam roller 43b of the third gear 43, which is engaged with the arm 35 of the counterweight 24, pushes down the counterweight 24. As a result, the counterweight 24 moves downward against the bias of the coil spring 23. In other words, the counterweight 24 descends while compressing the coil spring 23. At the same time, the engagement of the stopper 27 with the counterweight 24 is completed.

[0055] Thereafter, the second gear 42 continues to rotate clockwise, and the third gear 43 continues to rotate counterclockwise, causing the cam roller 42b of the second gear 42 to further push up the plunger 21. As a result, the plunger 21 continues to compress the coil spring 23 and rises to the top dead center shown in FIG.

[0056] Meanwhile, the cam roller 43b of the third gear 43 moves away from the arm 35 of the counterweight 24. In other words, the engagement between the cam roller 43b and the counterweight 24 is released. However, the engagement of the stopper 27 with the counterweight 24 is completed before the engagement between the cam roller 43b and the counterweight 24 is released.

[0057] 4 before the plunger 21. After reaching the top dead center, the counterweight 24 is held at the top dead center by the stopper 27.

[0058] When the plunger 21 rises to the top dead center, the cam roller 42b of the second gear 42 separates from the arm 33 of the plunger 21. In other words, the cam roller 42b is disengaged from the plunger 21. Then, the plunger 21 receives the restoring force (biasing force) of the coil spring 23 and descends to the bottom dead center shown in FIG. 5, and the driver blade 22 attached to the plunger 21 also descends to the bottom dead center shown in FIG. 5.

[0059] Even when the cam roller 42b and the plunger 21 are disengaged, the restriction on the movement of the counterweight 24 by the stopper 27 is not released. In other words, the counterweight 24 does not start rising at the same time that the plunger 21 starts to descend.

[0060] The movement restriction of the stopper 27 on the counterweight 24 is released after the plunger 21 descends to a predetermined position. The counterweight 24, whose movement restriction has been released, rises to the bottom dead center shown in FIG. 5 due to the restoring force (biasing force) of the coil spring 23.

[0061] As described above, the plunger 21 and the counterweight 24 move in opposite directions. The driver blade 22, which moves integrally with the plunger 21, strikes the nail supported by the ejection unit 4 during the movement.

[0062] At this time, the counterweight 24 moves in the opposite direction to the plunger 21 and the driver blade 22, thereby reducing the reaction when the driver blade 22 strikes the nail.

[0063] In this way, one driving operation is completed. If the conditions for continuing the driving operation are not satisfied when the driving operation is completed, the controller 6 shown in FIG. 1 stops the motor 44 without proceeding to the next driving operation.

[0064] For example, if the operation on the trigger lever 7 is released when the driving operation is completed, the controller 6 stops the motor 44. More specifically, the controller 6 switches the motor 44 from an operating state to a stopped state.

[0065] However, the controller 6 does not stop the motor 44 immediately after the completion of the driving operation. The controller 6 stops the motor 44 after moving the plunger 21 and the counterweight 24 to the standby position shown in FIG. 3 in preparation for the next driving operation.

[0066] Specifically, the controller 6 keeps the motor 44 in an operating state even after the driving operation is completed. As a result, the cam roller 41a of the first gear 41 shown in Fig. 5 re-engages with the plunger 21 and pushes up the plunger 21. Also, the cam roller 43a of the third gear 43 re-engages with the counterweight 24 and pushes down the counterweight 24.

[0067] Next, before the cam roller 41a of the first gear 41 is disengaged from the arm 31 of the plunger 21, the cam roller 42a of the second gear 42 engages with the arm 32 of the plunger 21 to continue pushing up the plunger 21.

[0068] Thereafter, before the cam roller 42a of the second gear 42 and the arm 32 of the plunger 21 are disengaged, the cam roller 42b of the second gear 42 engages with the arm 33 of the plunger 21, pushing the plunger 21 up to the standby position.

[0069] Furthermore, before the cam roller 43a of the third gear 43 disengages from the arm 35 of the counterweight 24, the cam roller 43b of the third gear 43 engages with the arm 35 of the counterweight 24 and pushes the counterweight 24 down to the standby position.

[0070] <Position Detector> The nailing machine 1A includes a position detector that detects the position of the counterweight 24. More specifically, the nailing machine 1A includes a microswitch 60 that is operated by the counterweight 24.

[0071] 3 and 4, when the counterweight 24 is located at the standby position or the top dead center, the protrusion 24a provided on the counterweight 24 abuts against and presses the actuator of the microswitch 60. Furthermore, the protrusion 24a continues to abut against and presses the actuator of the microswitch 60 while the counterweight 24 moves from the standby position to the top dead center.

[0072] While the actuator is being pressed by the protrusion 24a of the counterweight 24, the microswitch 60 outputs a detection signal. The detection signal output from the microswitch 60 is input to the controller 6.

[0073] 5, when the counterweight 24 starts to move from the top dead center toward the bottom dead center, the protrusion 24a separates from the actuator of the microswitch 60. Then, the microswitch 60 stops outputting a detection signal, and the input of the detection signal to the controller 6 is cut off.

[0074] From another perspective, the counterweight 24 moving from the top dead center toward the bottom dead center passes through a fourth position between the top dead center and the bottom dead center. When the counterweight 24 passes through the fourth position (leaves the fourth position), the microswitch 60 turns OFF, and the detection signal ceases.

[0075] <Motor Control> As described above, after one driving operation is completed, the controller 6 moves the plunger 21 and the counterweight 24 to the standby position and then stops the motor 44. The control of the motor 44 by the controller 6 will be described in more detail.

[0076] The controller 6 acquires both the first information and the second information when the motor 44 is in an operating state, and switches the motor 44 to a stopped state when at least the first information satisfies a predetermined condition or the second information satisfies a predetermined condition.

[0077] In this embodiment, the first information is information about position, and the second information is information about time. More specifically, the first information is information about the position of the impact part (plunger 21). On the other hand, the second information is information about the elapsed time from the time when the counterweight 24 started to move from a predetermined position toward another predetermined position.

[0078] <<Control Based on First Information>> From the above explanation, it can be seen that the counterweight 24 is a moving member that moves in conjunction with the striking section including the plunger 21. Therefore, information regarding the position of the counterweight 24 is also information regarding the position of the plunger 21.

[0079] As described above, when the counterweight 24 moves to the standby position, the microswitch 60 turns ON and a detection signal is input to the controller 6. Therefore, the controller 6 can directly detect that the counterweight 24 has moved to the standby position based on the detection result of the microswitch 60. When the counterweight 24 is located at the standby position, the plunger 21 is also located at the standby position (FIG. 3).

[0080] Therefore, the controller 6, which can directly detect the movement of the counterweight 24 to the standby position, can indirectly detect the movement of the plunger 21 to the standby position.

[0081] The controller 6 keeps the motor 44 in an operating state until a detection signal is input from the microswitch 60, even if the conditions for continuing the driving operation are not satisfied when the driving operation is completed.

[0082] Thereafter, when the controller 6 receives the detection signal output from the microswitch 60, it determines that the first information satisfies the predetermined condition. The controller 6, having determined that the first information satisfies the predetermined condition, switches the motor 44 to a stopped state as adjustment control. As a result, the plunger 21 and the counterweight 24 stop at the standby position.

[0083] As described above, the first information satisfying the specified conditions means that the detection signal output from the microswitch 60 is input to the controller 6, and the counterweight 24 moves to a position (standby position) where the microswitch 60 is turned ON, or the plunger 21 moves until the counterweight 24 moves to a position where the microswitch 60 is turned ON.

[0084] Normally, when the driving operation starts (when the motor 44 is started), the plunger 21 and the counterweight 24 are in the standby position. Therefore, a detection signal is input to the controller 6 simultaneously with or immediately after the start of the driving operation. However, if the motor 44 is stopped based on the input of such a detection signal, it is obvious that the driving operation will not be performed.

[0085] Therefore, if a detection signal is input before a predetermined time (dead time) has elapsed since the motor 44 was started, the controller 6 does not determine that the first information satisfies the predetermined condition, and maintains the operating state of the motor 44. In other words, the controller 6 ignores the detection signal input within the dead time.

[0086] Instead of setting a dead time, the first input detection signal may be ignored. In this case, when the second detection signal is input, the controller 6 determines that the first information satisfies the predetermined condition and switches the motor 44 to the stopped state.

[0087] <<Control Based on Second Information>> The time required for the counterweight 24 to return to the standby position after starting to move from the top dead center toward the bottom dead center is the same as or substantially the same as the time required for the plunger 21 to return to the standby position after starting to move from the top dead center toward the bottom dead center.

[0088] Therefore, if the time elapsed from the time when the counterweight 24 starts to move from the top dead center toward the bottom dead center exceeds a predetermined time, the counterweight 24 should have returned to the standby position, and the plunger 21 should also have returned to the standby position.

[0089] As described above, when the counterweight 24 starts to move from the top dead center toward the bottom dead center, the microswitch 60 turns OFF, and the input of the detection signal to the controller 6 is discontinued. Therefore, based on the detection result of the microswitch 60, the controller 6 can directly detect that the counterweight 24 has started to move from the top dead center toward the bottom dead center.

[0090] The controller 6 starts the counter when it detects that the counterweight 24 has started to move from the top dead center toward the bottom dead center. More specifically, the controller 6 starts the counter when the input of the detection signal is discontinued.

[0091] When the time measured by the counter, i.e., the time elapsed since the counterweight 24 started to move from the top dead center toward the bottom dead center, exceeds a predetermined threshold time, the controller 6 determines that the second information satisfies the predetermined condition and switches the motor 44 to a stopped state, causing the plunger 21 and the counterweight 24 to stop at the standby position.

[0092] In other words, the second information satisfying the specified condition means that the control amount (elapsed time) from the point at which the counterweight 24 starts to move from top dead center toward bottom dead center exceeds the first specified amount (threshold time), or that the control amount (elapsed time) from the point at which the plunger 21 starts to move from top dead center toward bottom dead center exceeds the first specified amount (threshold time), or that the control amount (elapsed time) from the point at which the counterweight 24 leaves the fourth position exceeds the first specified amount (threshold time).

[0093] The threshold time, which is an example of the first predetermined amount, is set in advance based on the time required for the counterweight 24 and plunger 21 to return to the standby position after starting to move from the top dead center toward the bottom dead center.

[0094] <Timing Chart> <Normal Operation> FIGS. 6 and 7 are timing charts showing the relationship between the output change of the microswitch 60 and the position change of the plunger 21 under normal operation.

[0095] More specifically, FIG. 6 is a timing chart showing the relationship between the change in output of the microswitch 60 and the change in position of the plunger 21 when the motor 44 is stopped based on the first information.

[0096] On the other hand, FIG. 7 is a timing chart showing the relationship between the change in output of the microswitch 60 and the change in position of the plunger 21 when the motor 44 is stopped based on the second information.

[0097] See Figure 6. As described above, after the previous driving operation was completed, the plunger 21 and counterweight 24 were returned to their standby positions. Therefore, the microswitch 60 is turned ON at the same time that the motor 44 is started. In other words, a detection signal is input to the controller 6 at the same time that the motor 44 is started. From another perspective, when the motor 44 is started, a detection signal is input to the controller 6 before the dead time T1 has elapsed.

[0098] In this case, even if a detection signal is input, the controller 6 does not determine that the first information satisfies the predetermined condition, and maintains the operating state of the motor 44. In other words, the controller 6 ignores the detection signal input during the dead time T1.

[0099] Thereafter, the plunger 21 reaches the top dead center at time t1 and then starts moving toward the bottom dead center. After the plunger 21 starts moving from the top dead center toward the bottom dead center, at time t2, the counterweight 24 also starts moving from the top dead center toward the bottom dead center. Then, the protrusion 24a of the counterweight 24 separates from the actuator of the microswitch 60. In other words, the microswitch 60 turns OFF at time t2, and the input of the detection signal to the controller 6 is discontinued.

[0100] Thereafter, the plunger 21 reaches the bottom dead center at time t3. Next, the plunger 21 and the counterweight 24 move from the bottom dead center toward the standby position and reach the standby position at time t4. Also, the protrusion 24a of the counterweight 24 presses the actuator of the microswitch 60. That is, the microswitch 60 turns ON at time t4, and a detection signal is input to the controller 6.

[0101] When the detection signal is input to the controller 6 after the dead time T1 has elapsed, the controller 6 determines that the first information satisfies the predetermined condition and switches the motor 44 to a stopped state, causing the plunger 21 and the counterweight 24 to stop at the standby position.

[0102] Please refer to Fig. 7. The changes up to time t3 shown in Fig. 7 are the same as the changes shown in Fig. 6. After time t3, the plunger 21 and the counterweight 24 move from the bottom dead center toward the standby position.

[0103] Thereafter, when the time measured by the counter activated at time t2 becomes equal to or greater than the threshold time T2, the controller 6 switches the motor 44 to a stopped state. As described above, time t2 is the time when the counterweight 24 starts to move from the top dead center toward the bottom dead center.

[0104] In other words, when the elapsed time from when the counterweight 24 started to move from the top dead center toward the bottom dead center exceeds the threshold time T2, the controller 6 determines that the second information satisfies the predetermined condition and switches the motor 44 to a stopped state, causing the plunger 21 and the counterweight 24 to stop at the standby position.

[0105] <<When an Abnormality Occurs>> FIGS. 8 and 9 are timing charts showing the relationship between the change in output of the microswitch 60 and the change in position of the plunger 21 when an abnormality occurs.

[0106] More specifically, FIG. 8 is a timing chart showing the relationship between the change in output of the microswitch 60 and the change in position of the plunger 21 when the load on the motor 44 becomes lighter for some reason.

[0107] For example, if nail clogging occurs or the coil spring 23 is damaged, the load on the motor 44 is reduced and the rotation speed of the motor 44 increases.

[0108] On the other hand, FIG. 9 is a timing chart showing the relationship between the change in output of the microswitch 60 and the change in position of the plunger 21 when the microswitch 60 fails.

[0109] For example, if the microswitch 60 breaks down due to vibration or impact during driving, no detection signal will be output even if the actuator is pressed.

[0110] Please refer to Fig. 8. The changes up to time t3 shown in Fig. 8 are the same as the changes during normal operation shown in Figs.

[0111] When the load on the motor 44 becomes lighter after time t3, the plunger 21 and the counterweight 24 reach (return to) their standby positions earlier than usual. From another perspective, the plunger 21 and the counterweight 24 reach their standby positions before the time measured by the counter activated at time t2 exceeds the threshold time T2. As a result, the microswitch 60 turns ON at time t5, before the time measured by the counter exceeds the threshold time T2.

[0112] When such an abnormality occurs, in a control where the timing to stop the motor 44 is determined based only on the second information, the plunger 21 and the counterweight 24 reach the standby position and the motor 44 cannot be switched to the stopped state even when the microswitch 60 is turned ON. As a result, the plunger 21 and the counterweight 24 move excessively toward the top dead center beyond the standby position.

[0113] However, in this embodiment, the controller 6 acquires not only the second information but also the first information when the motor 44 is in an operating state. Furthermore, the controller 6 switches the motor 44 to a stopped state when at least one of the first information and the second information satisfies a predetermined condition.

[0114] That is, when a detection signal is input at time t5 (when the first information satisfies the predetermined condition), the controller 6 switches the motor 44 to a stopped state even if the time measured by the counter does not exceed the threshold time T2 (even if the second condition does not satisfy the predetermined condition). As a result, the plunger 21 and the counterweight 24 stop at the standby position.

[0115] Please refer to Fig. 9. The changes up to time t3 shown in Fig. 9 are the same as the changes during normal operation shown in Figs.

[0116] If the microswitch 60 fails, the microswitch 60 will not be turned on even if the plunger 21 and the counterweight 24 reach the standby position after time t3, and no detection signal will be input to the controller 6.

[0117] When such an abnormality occurs, in a control where the timing to stop the motor 44 is determined based only on the first information, the plunger 21 and the counterweight 24 move to the standby position, and the motor 44 cannot be switched to the stopped state even if the actuator of the microswitch 60 is pressed. As a result, the plunger 21 and the counterweight 24 move excessively toward the top dead center beyond the standby position.

[0118] However, in this embodiment, the controller 6 acquires not only the first information but also the second information when the motor 44 is in an operating state. Furthermore, the controller 6 switches the motor 44 to a stopped state when at least one of the first information and the second information satisfies a predetermined condition.

[0119] In other words, when the elapsed time from time t2 exceeds the threshold time T2 (when the second information satisfies the predetermined condition), the controller 6 switches the motor 44 to the stopped state even if a detection signal is not input (even if the first information does not satisfy the predetermined condition), and as a result, the plunger 21 and the counterweight 24 stop at the standby position.

[0120] (Second embodiment) <Outline of electric tacker> A work machine according to this embodiment is suitable for driving fasteners such as nails and staples into mating materials such as wood, gypsum board, etc. More specifically, the work machine according to this embodiment is an electric tacker that drives U-shaped staples into mating materials.

[0121] 10 is a side view showing the structure of an electric tacker 1B according to this embodiment. The electric tacker 1B has a housing 102, a magazine 103, an ejection unit 104, and the like.

[0122] The housing 102 has substantially the same structure as the housing 2. More specifically, the housing 102 has a handle portion 111 and a motor accommodating portion 112 that extend rearward from the main body portion 110. The housing 102 also has a connecting portion 113 that connects the rear ends of the handle portion 111 and the motor accommodating portion 112 together.

[0123] A plurality of staples are loaded into the magazine 103. The plurality of staples loaded in the magazine 103 are supplied one by one to the ejection unit 104. The ejection unit 104 supports the staples fed from the magazine 103 so that they can be ejected.

[0124] When a predetermined operation is performed on an operating section including a trigger lever 107 provided on the handle portion 111, the staples supported by the ejection portion 104 are struck by an impact mechanism 120, which will be described later. As a result, the staples are ejected from the ejection portion 104 and driven into the mating material.

[0125] 11 is an enlarged perspective view showing the impact mechanism 120 of the electric tacker 1B. The impact mechanism 120 is composed of a plunger 121, a driver blade 122, a coil spring 123, a guide shaft 123a, a gear 141, etc., which are housed in the main body 110.

[0126] The plunger 121 and the driver blade 122 are capable of striking the staples supported by the ejection portion 104 and correspond to the striking portion of the present invention. The coil spring 123 is capable of biasing the plunger 121 and the driver blade 122 downward and corresponds to the biasing portion of the present invention.

[0127] <Operation of the Impact Mechanism> The controller 106 shown in Fig. 10 can switch the state of the motor 144 shown in the same figure based on predetermined conditions and information. For example, when the plunger 121 is located in the fifth position (standby position) and a predetermined operation is performed on the operation unit including the trigger lever 107, the controller 106 switches the motor 144 from a stopped state to an operating state. More specifically, the controller 106 supplies power from the battery pack 105 to the motor 144 to switch the motor 144 from a stopped state to an operating state.

[0128] When the motor 144 is switched to an operating state, a driving force is input to the gear 141 shown in Fig. 11 via a planetary gear type reduction mechanism 145. This causes the gear 141 to rotate. In other words, the gear 141 is a rotating part that rotates due to the driving force output from the motor 144.

[0129] Cam rollers 141a and 141b are provided on the front surface of the gear 141. The cam roller 141a engages with the plunger 121 when the plunger 121 is located at the standby position.

[0130] Therefore, when the gear 141 rotates while the plunger 121 is in the standby position, the cam roller 141a pushes up the plunger 121. The cam roller 141b engages with the plunger 121 before the cam roller 141a separates from the plunger 121, and continues to push up the plunger 121.

[0131] As a result, the plunger 121 moves from the standby position toward the second position (top dead center) against the bias of the coil spring 123. In other words, the plunger 121 moves (rises) in the second direction while compressing the coil spring 123.

[0132] When the plunger 121 rises to the top dead center, the cam roller 141b is disengaged from the plunger 121. Then, the plunger 121 receives the restoring force (biasing force) of the coil spring 123 and descends to the third position (bottom dead center).

[0133] Furthermore, the driver blade 122 attached to the plunger 121 also descends to the bottom dead center together with the plunger 121. During the movement of the driver blade 122, the driver blade 122 strikes the staples supported by the ejection portion 104. In this manner, one driving operation is completed.

[0134] As described above, the fifth position of the plunger 121 in this embodiment is the standby position. That is, the fifth position in this embodiment is the same as or substantially the same as the first position in the first embodiment.

[0135] Also, in this embodiment, the fifth position (standby position), the second position (top dead center), and the third position (bottom dead center) each have a position range with a certain degree of width and are not limited to a single point.

[0136] <Position Detector> The electric tacker 1B includes a position detector that detects the position of the plunger 121. More specifically, the electric tacker 1B includes a microswitch 160 that is operated by the plunger 121.

[0137] When the plunger 121 is at the top dead center, it comes into contact with the actuator of the microswitch 160 and presses the actuator. While the actuator is being pressed by the plunger 121, the microswitch 160 outputs a detection signal. The detection signal output from the microswitch 160 is input to the controller 106.

[0138] On the other hand, when the plunger 121 starts to move from the top dead center toward the bottom dead center and separates from the actuator of the microswitch 160, the detection signal is no longer output from the microswitch 160. In other words, when the plunger 121 starts to move from the top dead center toward the bottom dead center, the input of the detection signal to the controller 106 is interrupted.

[0139] However, the actuator of the microswitch 160 has a certain stroke, so the microswitch 160 does not switch from ON to OFF the instant the plunger 121 starts to move from the top dead center toward the bottom dead center.

[0140] From another perspective, the plunger 121, which moves from the top dead center toward the bottom dead center, passes through a sixth position between the top dead center and the bottom dead center. When the plunger 121 passes through the sixth position (leaves the sixth position), the microswitch 160 switches from ON to OFF, and the detection signal is no longer output.

[0141] As described above, the sixth position of plunger 121 in this embodiment is the position where microswitch 160, which is the position detector, is turned OFF. In other words, the sixth position in this embodiment is the same as or substantially the same as the fourth position in the first embodiment.

[0142] <Control of Motor> The controller 106 keeps the motor 144 in an operating state even after one driving operation is completed, and moves the plunger 121 to the standby position. The control of the motor 144 by the controller 106 will be described in more detail.

[0143] The controller 106 starts the counter when the plunger 121 leaves the sixth position. More specifically, the controller 106 starts the counter when the microswitch 160 is turned OFF and the input of the detection signal is discontinued.

[0144] When the time measured by the counter, that is, the time elapsed since the plunger 121 left the sixth position, exceeds a predetermined stop time, the controller 106 switches the motor 144 to a stop state, causing the plunger 121 to stop at the standby position.

[0145] From another perspective, the controller 106 switches the motor 144 to a stopped state when the control amount (elapsed time) from the time when the plunger 121 leaves the sixth position exceeds a first predetermined amount (stop time).

[0146] The controller 106 also acquires the first information when the motor 144 is in an operating state. Furthermore, the controller 106 performs adjustment control based on the first information to adjust the stop position of the plunger 121 to coincide with the standby position.

[0147] In this embodiment, the first information is the control amount (elapsed time) required for plunger 121 located at the standby position to be positioned at the sixth position.

[0148] As described above, when the trigger lever 107 is operated and the motor 144 is put into an operating state, the plunger 121, which is located at the standby position, moves to the top dead center. As a result, the microswitch 160 is turned ON, and a detection signal is output.

[0149] Thereafter, the plunger 121 passes through the sixth position and moves to the bottom dead center. When the plunger 121 passes through (leaves from) the sixth position, the microswitch 160 is turned OFF, and the detection signal is discontinued.

[0150] From another perspective, the control amount (elapsed time) as the first information is the response time required from when the trigger lever 107 is operated until the driving operation is executed.

[0151] The control amount (elapsed time / response time) as the first information increases or decreases depending on, for example, the voltage (battery voltage) of the battery pack 105. More specifically, the control amount (elapsed time / response time) as the first information becomes shorter when the battery voltage is high, and becomes longer when the battery voltage is low.

[0152] Furthermore, when the battery voltage is high, the speed at which the motor 144 drives the plunger 121 increases, and when the battery voltage is low, the speed at which the motor 144 drives the plunger 121 decreases.

[0153] Therefore, if the first predetermined amount (stop time) is fixed, there is a risk that the stop position of the plunger 121 may move forward or backward relative to the standby position.

[0154] Therefore, the controller 106 changes the first predetermined amount (stop time) in accordance with the control amount (elapsed time / response time) as the first information, thereby suppressing variations in the stop position of the plunger 121 caused by disturbances (e.g., changes in battery voltage).

[0155] <Timing Chart> <Normal Operation> FIG. 12 is a timing chart showing the relationship between the output change of the microswitch 160 and the position change of the plunger 121 under normal operation.

[0156] More specifically, FIG. 12 is a timing chart showing the relationship between the change in output of the microswitch 160 and the change in position of the plunger 121 when the control amount (elapsed time / response time) required for the plunger 121, which is located in the standby position, to be positioned at the sixth position is a second predetermined amount.

[0157] In this embodiment, the second predetermined amount is 55 ms. That is, Fig. 12 is a timing chart showing the relationship between the change in output of the microswitch 160 and the change in position of the plunger 121 when the response time is 55 ms.

[0158] From another perspective, the plunger 121, which is normally located at the standby position, is located at the sixth position at time t11, 55 ms after the trigger lever 107 is operated.

[0159] In this case, the controller 106 sets the first predetermined amount (stop time) to 120 ms. That is, the controller 106 switches the motor 144 from an operating state to a stopped state at time t12, which is 120 ms after the microswitch 160 is turned OFF.

[0160] In other words, when the control amount (elapsed time) from the time when the plunger 121 leaves the sixth position exceeds 120 ms, the controller 106 switches the motor 144 from an operating state to a stopped state. It is needless to say that 120 ms is an example of the first predetermined amount (stop time).

[0161] <<When the Elapsed Time (Response Time) is Short>> FIG. 13 is a timing chart showing the relationship between the change in output of the microswitch 160 and the change in position of the plunger 121 when the response time is shorter than the second predetermined amount.

[0162] More specifically, FIG. 13 is a timing chart showing the relationship between the change in output of the microswitch 160 and the change in position of the plunger 121 when the response time is 45 ms.

[0163] In this case, the controller 106 sets the first predetermined amount (stop time) shorter than normal. That is, when the response time is shorter than the second predetermined amount, the controller 106 sets the first predetermined amount (stop time) shorter.

[0164] Specifically, if the response time is shorter than the second predetermined amount, the controller 106 shortens the first predetermined amount (stop time) by 1 ms. In other words, the controller 106 switches the motor 144 from an operating state to a stopped state 119 ms after the microswitch 160 is turned off.

[0165] As a result, even if the driving speed of the plunger 121 becomes faster than normal for some reason, the stop position of the plunger 121 is made to coincide with the standby position.

[0166] However, if the response time is still shorter than the second predetermined amount during the next driving operation, the controller 106 executes the above-described adjustment control again, shortening the first predetermined amount (stop time) by 1 ms each time until the response time matches the second predetermined amount.

[0167] <<When the Elapsed Time (Response Time) is Long>> FIG. 14 is a timing chart showing the relationship between the change in output of the microswitch 160 and the change in position of the plunger 121 when the response time is longer than the second predetermined amount.

[0168] More specifically, FIG. 14 is a timing chart showing the relationship between the change in output of the microswitch 160 and the change in position of the plunger 121 when the response time is 65 ms.

[0169] In this case, the controller 106 sets the first predetermined amount (stop time) longer than normal. That is, when the response time is longer than the second predetermined amount, the controller 106 sets the first predetermined amount (stop time) longer.

[0170] Specifically, if the response time is longer than the second predetermined amount, the controller 106 extends the first predetermined amount (stop time) by 1 ms. In other words, the controller 106 switches the motor 144 from an operating state to a stopped state 121 ms after the microswitch 160 is turned off.

[0171] As a result, even if the driving speed of the plunger 121 is slower than normal for some reason, the stop position of the plunger 121 is made to coincide with the standby position.

[0172] However, if the response time is still longer than the second predetermined amount during the next driving operation, the controller 106 again executes the above-described adjustment control, i.e., lengthens the first predetermined amount (stop time) by 1 ms until the response time matches the second predetermined amount.

[0173] The reason why the amount of adjustment for each time is set to ±1 ms is to avoid sudden changes in behavior, and therefore the amount of adjustment for each time may be changed within a range that can avoid sudden changes in behavior.

[0174] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention. For example, the microswitch 60 may detect the position of the striking portion (plunger 21), and the motor 44 may be switched from an operating state to a stopped state based on the detection result. From another perspective, the microswitch 60 may be installed in a position where the actuator can be operated by the plunger 21 that has moved to the standby position.

[0175] Furthermore, the position detection unit that detects the position of the plunger 21, 121 or the counterweight 24 is not limited to a microswitch. For example, the position detection unit may be a sensor (e.g., a Hall IC or an optical sensor) that detects the position of a detection object such as the plunger 21, 121 or the counterweight 24 without contacting the detection object, or may be a unit that indirectly detects the position of the plunger 21, 121 or the counterweight 24 by detecting the amount of rotation or rotation angle of a rotating part (e.g., a gear included in the gear group 25).

[0176] The rotation amount of the motor 44 may be used as the control amount instead of the elapsed time. In this case, the first predetermined amount is a threshold value for the rotation amount of the motor 44. Alternatively, a current detection unit may be provided that detects the value of a current flowing through the motor 44, and the integrated value of the current detected by the current detection unit may be used as the control amount. In this case, the first predetermined amount is a threshold value for the integrated value of the current.

[0177] The fifth position in the second embodiment may be a position different from the first position in the first embodiment and may not be a standby position. Similarly, the sixth position in the second embodiment may be a position different from the fourth position in the first embodiment.

[0178] From another perspective, the fifth and sixth positions in the second embodiment may be any positions that allow measurement of the drive speed of plunger 121. Therefore, in another embodiment, the position where microswitch 160 is ON is defined as the fifth position, and the position where microswitch 160 is OFF is defined as the sixth position.

[0179] In yet another embodiment, the standby position is the fifth position, and any position between the standby position and the top dead center is the sixth position.

[0180] In another embodiment, the striking portion is comprised of a piston and a driver blade, and the striking portion is comprised of a cylinder having compressed air stored therein.

[0181] 1A... Nail gun, 1B... Electric tacker, 2,102... Housing, 3,103... Magazine, 4,104... Injection unit, 5,105... Battery pack, 6,106... Controller, 7,107... Trigger lever, 10,110... Main body, 11,111... Handle, 12,112... Motor housing, 13,113... Connection unit, 20,120... Striking mechanism, 21,121... Plunger, 22,122... Driver blade, 23,123... Coil spring, 23a,123a... Guide shaft, 24... Counterweight, 24a... Thrust 25...gear group, 26...guide bar, 27...stopper, 31, 32, 33...arm, 34...pin, 35...arm, 41...first gear, 41a...cam roller, 42...second gear, 42a, 42b...cam roller, 43...third gear, 43a, 43b...cam roller, 44, 144...motor, 45...gear box, 51...bottom holder, 52...top holder, 53...lower damper (plunger damper), 54...upper damper (weight damper), 60, 160...microswitch, 141...gear, 141a, 141b...cam roller

Claims

1. A motor; an ejection section supporting a stopper; a striking section movable in a first direction and a second direction opposite to the first direction and capable of striking the stopper supported by the ejection section by moving in the first direction; a biasing section biasing the striking section in the first direction; a control section capable of switching the motor between an operating state in which a driving force is output and a stopped state in which no driving force is output; and a rotating section rotated by the driving force output from the motor, wherein the striking section is located at a first position and engaged with the rotating section, when the rotating section rotates, the striking section moves in the second direction from the first position to the second position against the biasing section, and when the striking section is disengaged from the rotating section at the second position, the striking section moves in the first direction from the second position to a third position due to the biasing section, and when the striking section re-engages with the rotating section at the third position, the striking section moves in the second direction from the third position to the first position against the biasing section, The control unit switches the motor to the stopped state when the control amount from the point at which the impact portion or a moving member that moves in conjunction with the impact portion leaves the fourth position exceeds a first predetermined amount, and the control unit performs adjustment control to adjust the stop position of the impact portion to coincide with the first position based on first information acquired when the motor is in the operating state.

2. A work machine as described in claim 1, wherein the first information is information relating to the position of the impact part.

3. A work machine as described in claim 2, wherein the first information is a detection signal output from a position detection unit which detects the position of at least one of the impact portion and the movable member.

4. A work machine as described in claim 3, wherein the position detection unit outputs the detection signal when the impact portion is located at the first position or at a position closer to the second position than the first position, and the control unit, as the adjustment control, switches the motor to the stopped state when the detection signal is input.

5. A work machine as described in claim 4, wherein the first information is the detection signal output from the position detection unit which detects the position of the movable member.

6. A work machine as described in claim 4 or claim 5, wherein the control unit maintains the motor in the operating state if the detection signal is input before a predetermined time has elapsed since starting the motor.

7. A work machine as described in claim 1, further comprising a position detection unit which detects the position of at least one of the impact portion and a movable member which moves in conjunction with the impact portion, and wherein the control unit changes the first predetermined amount as the adjustment control in accordance with the control amount required for the impact portion, which is located at the fifth position, to be positioned at the sixth position.

8. A work machine as described in claim 7, wherein the control unit lengthens the first predetermined amount when the control amount required for the impact part, which is located at the fifth position, to be positioned at the sixth position is longer than a second predetermined amount, and shortens the first predetermined amount when the control amount is shorter than the second predetermined amount.

9. A work machine as described in claim 8, wherein the fifth position is the same as the first position, and the striking portion engages with the rotating portion and moves from the fifth position to the second position, and then disengages from the rotating portion and moves from the second position to the third position, while being positioned at the sixth position.

10. The work machine of claim 7, wherein said sixth position is the same as said fourth position.

11. A motor; an ejection section supporting a stopper; a striking section movable in a first direction and a second direction opposite to the first direction and capable of striking the stopper supported by the ejection section by moving in the first direction; a biasing section biasing the striking section in the first direction; a control section capable of switching the motor between an operating state in which a driving force is output and a stopped state in which no driving force is output; and a rotating section rotated by the driving force output from the motor, wherein the striking section is located at a first position and when the rotating section rotates while engaged with the rotating section, the striking section moves in the second direction from the first position to the second position against the biasing section, and when the striking section is disengaged from the rotating section at the second position, the striking section moves in the first direction from the second position to a third position due to the biasing section, and when the striking section re-engages with the rotating section at the third position, the striking section moves in the second direction from the third position to the first position against the biasing section, The control unit acquires first information and second information when the motor is in the operating state, and when at least one of the first information and the second information satisfies a predetermined condition, switches the motor to the stopped state and stops the impact unit at the first position.

12. A work machine as described in claim 11, wherein the first information is information regarding the position of the striking part, and the second information is information regarding the elapsed time from the point at which the striking part or a moving member that moves in conjunction with the striking part starts to move from a predetermined position toward another predetermined position.

13. The work machine according to claim 12, wherein the first information is a detection signal output from a position detection unit that detects the position of at least one of the striking unit and the movable member.

14. A work machine as described in claim 13, wherein the position detection unit outputs the detection signal when the impact portion is located at the first position or at a position closer to the second position than the first position, and when the detection signal is input, the control unit determines that the first information satisfies a predetermined condition and switches the motor to the stopped state.

15. The work machine according to claim 12, wherein the control unit, when the elapsed time exceeds a predetermined time, determines that the second information satisfies a predetermined condition and switches the motor to the stopped state.

16. A device comprising: a motor; an ejection section supporting a stopper; a striking section movable in a first direction and a second direction opposite to the first direction and capable of striking the stopper supported by the ejection section by moving in the first direction; a biasing section biasing the striking section in the first direction; a control section capable of switching the motor between an operating state in which a driving force is output and a stopped state in which no driving force is output; a rotating section rotated by the driving force output from the motor; and a position detection section outputting a detection signal when the striking section is located at a first position or a position closer to a second position than the first position; wherein the striking section is located at the first position and engaged with the rotating section, and when the rotating section rotates, the striking section moves in the second direction from the first position to the second position against the biasing section; and when the striking section is disengaged from the rotating section at the second position, the striking section moves in the first direction from the second position to a third position due to the biasing section; A work machine in which, when the impact portion engages with the rotating portion again at the third position, it moves in the second direction from the third position to the first position against the force of the force portion, and the control portion switches the motor to the stopped state when a control amount from a point in time when the impact portion or a moving member that moves in conjunction with the impact portion leaves the fourth position exceeds a first predetermined amount, and the control portion switches the motor to the stopped state when the detection signal is input, and maintains the motor in the operating state if the detection signal is input before a predetermined time has elapsed since the motor was started.

Images