Work equipment

Abstract

To improve the usability of the work equipment. [Solution] The driving machine includes an injection unit, a striking unit that strikes a fastener supported by the injection unit, a biasing unit that biases the striking unit downward, a drive unit, a rotating unit that moves the striking unit to the bottom dead center S1 by the biasing force of the biasing unit by releasing its engagement with the striking unit, and a control unit that controls the drive of the drive unit. The rotating unit can switch between a plurality of states, including an engageable state in which it can engage with the striking unit and an unengaged state in which it cannot engage with the striking unit. The control unit performs brake control by applying a braking force to the drive unit, so that after the engagement of the rotating unit with the striking unit is released at the top dead center P1 and the striking unit reaches the bottom dead center S1, the rotating unit is maintained in the unengaged state for a predetermined time.

Description

Technical Field

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[0001] The present invention relates to a working machine such as a driving machine.

Background Art

[0002] As an example of a working machine, a driving machine having a driver blade for striking a fastener, a pin wheel for pushing up the driver blade, and a motor for rotating the pin wheel is known.

[0003] As such a driving machine, for example, Patent Document 1 discloses a driving machine provided with a mechanism in which a rack provided on a driver blade and a pin provided on a pin wheel are engaged, and after driving, the driver blade is pushed up by the rotation of the pin wheel.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the driving machine described in Patent Document 1 above, after the driver blade strikes, it may collide with a bumper at the bottom dead center and bounce. When the driver blade bounces, the rack may be positioned above the original position where the driver blade is located at the bottom dead center.

[0006] When the pin wheel rotates to a position where it can engage with the rack in a state where the rack of the driver blade is positioned above the original position as described above, there is a risk that the rack and the pin wheel will collide and be damaged. For this reason, there has been a demand to suppress the collision between the rack and the pin wheel and improve convenience.

[0007] The objective of this invention is to provide a work machine with improved convenience. [Means for solving the problem]

[0008] A working machine in one embodiment includes an injection unit, a striking unit that strikes a fastener supported by the injection unit by moving to one side in a first direction, a biasing unit that biases the striking unit to one side in the first direction, a drive unit, and a mechanism that rotates by receiving the driving force of the drive unit while engaged with the striking unit, thereby moving the striking unit to the other side in the first direction against the biasing force of the biasing unit, and then disengaging from the striking unit, thereby moving the striking unit to the bottom dead center on one side in the first direction by the biasing force of the biasing unit. The device comprises a rotating part and a control unit that controls the drive of the drive unit, wherein the rotating part can switch between multiple states, including an engageable state in which it can engage with the striking part and an unengageable state in which it cannot engage with the striking part, by the rotation of the rotating part, and the control unit maintains the rotating part in the unengageable state for a predetermined time after the engagement of the rotating part with the striking part is released and the striking part moves to one side in the first direction and reaches the bottom dead center.

[0009] The work machine of another embodiment includes an injection unit, a striking unit that moves to one side in a first direction to strike a fastener supported by the injection unit, a biasing unit that biases the striking unit to one side in the first direction, a drive unit, a rotating unit that rotates by receiving the driving force of the drive unit while engaged with the striking unit, thereby moving the striking unit to the other side in the first direction against the biasing force of the biasing unit, and then disengaging from the striking unit to move the striking unit to the bottom dead center in one side in the first direction by the biasing force of the biasing unit, a control unit that controls the drive of the rotating unit, and a striking unit position detection unit that detects the position of the striking unit by contacting the striking unit, wherein the control unit can execute a plurality of controls including a first control that rotates the rotating unit at a first rotational speed and a second control that rotates the rotating unit at a second rotational speed smaller than the first rotational speed, and switches the control of the rotational speed based on the detection result of the striking unit position detection unit. [Effects of the Invention]

[0010] According to the present invention, the convenience of the work machine can be improved. [Brief explanation of the drawing]

[0011] [Figure 1] This is a side view showing the external structure of a work machine according to an embodiment of the present invention. [Figure 2] This is a cross-sectional view showing the structure cut along line AA in Figure 1. [Figure 3] Figure 1 is a block diagram of the control system for the work machine shown. [Figure 4] Figure 1 is a piecewise diagram showing the relationship between signal, rotation speed, and blade position over time in the continuous firing mode of the work machine. [Figure 5] Figure 1 is a piecewise diagram showing the relationship between signal, duty cycle, and blade position over time in the continuous firing mode of the work machine. [Figure 6] Figure 4 is a partial rear view showing the state of the rotating and striking parts at the sensor reaction position L1 of the work machine's control system. [Figure 7] Figure 4 is a partial rear view showing the state of the rotating and striking parts at the top dead center P1 of the control mechanism of the work machine. [Figure 8] Figure 4 is a partial rear view showing the state of the rotating and striking parts at the bottom dead center S1 of the control of the work machine. [Figure 9] Figure 4 is a partial rear view showing the state of the rotating and striking parts in the re-hoisting U1 control of the work machine. [Figure 10] Figure 1 is a piecewise diagram showing the relationship between signal, rotational speed, and blade position over time in the single-shot mode of the work machine. [Figure 11] Figure 1 is a piecewise diagram showing the relationship between signal, duty cycle, and blade position over time in the single-shot mode of the work machine. [Figure 12] Figure 10 is a partial rear view showing the state of the rotating and striking parts at top dead center V1 of the control mechanism of the work machine. [Figure 13]It is a partial rear view showing the states of the rotating part and the striking part at the bottom dead point W1 of the control of the working machine in FIG. 10. [Figure 14] It is a partial rear view showing the states of the rotating part and the striking part at the rewinding X1 of the control of the working machine in FIG. 10. [Figure 15] It is a partial rear view showing the states of the rotating part and the striking part at the sensor reaction position Y1 of the control of the working machine in FIG. 10. [Figure 16] It is a partial rear view showing the states of the rotating part and the striking part at the standby position Z1 of the control of the working machine in FIG. 10.

Embodiments for Carrying Out the Invention

[0012] The working machine of the embodiment of the present invention will be described with reference to the drawings. In this embodiment, as an example of the working machine, the driving machine 10 will be taken up, and further, as an example of the fastener, the nail 78 will be taken up and described.

[0013] (Embodiment) The driving machine (working machine) 10 of the present embodiment shown in FIGS. 1 to 3 is a pneumatic working machine, and has a housing 11, a striking part 12, a nose part 13, a power supply part 14, an electric motor (driving part) 15, a winding-up mechanism 17 and a pressure accumulator 18. The housing 11 is an outer shell element of the driving machine 10, and has a cylinder case 19, a handle 20, a motor case 21 and a mounting part 22. The cylinder case 19 is cylindrical, and the handle 20 and the motor case 21 are connected to the cylinder case 19. Further, the mounting part 22 is connected to the handle 20 and the motor case 21.

[0014] The power supply part 14 can be attached to and detached from the mounting part 22. The electric motor 15 is arranged in the motor case 21. A head cover 25 is provided on the cylinder case 19, and the pressure accumulator 18 is arranged across the inside of the cylinder case 19 and the inside of the head cover 25.

[0015] Furthermore, a cylinder 27 is housed within the cylinder case 19, and the accumulator 18 has a cap 23 and a holder 24 attached to the cylinder 27. The cylinder 27 is made of metal, for example, aluminum or iron. The cylinder 27 is positioned relative to the cylinder case 19 in the direction along the centerline A1 and in the radial direction. The centerline A1 passes through the center of the cylinder 27. The radial direction is the radial direction of a virtual circle centered on the centerline A1. A pressure chamber 26 is formed within the accumulator 18 and the cylinder 27. The pressure chamber 26 is filled with compressed gas. The compressed gas can be air or an inert gas. Examples of inert gases include nitrogen gas and noble gases. In this embodiment, an example in which the pressure chamber 26 is filled with air will be described. The pressure chamber 26 also serves as a biasing part that biases the striking part 12 downward (one side) in the vertical direction (first direction) M1.

[0016] The striking section 12 is positioned from the inside to the outside of the housing 11. The striking section 12 includes a piston 28 and a driver blade 29. The piston 28 is operable within the cylinder 27 in a direction along the centerline A1. An annular sealing member 84 is attached to the outer circumferential surface of the piston 28. The sealing member 84 contacts the inner circumferential surface of the cylinder 27 to form a sealing surface. The driver blade 29 is made of metal, non-ferrous metal, or steel, for example. The piston 28 and the driver blade 29 are provided as separate components and are connected to each other.

[0017] As a result, the striking part 12 can strike the nail (fastener) 78 by moving downward (to one side) in the vertical direction (first direction) M1.

[0018] The nose section 13 is positioned both inside and outside the cylinder case 19. The nose section 13 has a bumper support section 31, an injection section 32, and a cylindrical section 33. The bumper support section 31 is cylindrical in shape. A bumper 35 is positioned inside the bumper support section 31. The bumper 35 may be made of synthetic rubber or silicone rubber. The bumper 35 has a guide hole 36. The center line A1 passes through the guide hole 36. The driver blade 29 is positioned inside the guide hole of the bumper support section 31 and inside the guide hole 36. The striking section 12 can operate in a driving direction D1 and a return direction D2 along the center line A1. The driving direction D1 and the return direction D2 are opposite directions. The driving direction D1 is the direction in which the piston 28 approaches the bumper 35. The return direction D2 is the direction in which the piston 28 moves away from the bumper 35. The striking section 12 is constantly biased in the driving direction D1 by the gas pressure of the pressure chamber 26. The operation of the striking section 12 in the driving direction D1 can be defined as downward. The operation of the striking section 12 in the return direction D2 can be defined as upward. The driving direction D1 is the same as the downward (one side) of the vertical direction (first direction) M1. The return direction D2 is the same as the upward (other side) of the vertical direction (first direction) M1.

[0019] Furthermore, the injection unit 32 is connected to the bumper support unit 31 and protrudes from the bumper support unit 31 in a direction along the center line A1. The injection unit 32 has an injection passage 37, which is provided along the center line A1. The driver blade 29 can operate within the injection passage 37 in a direction along the center line A1. As a result, the striking unit 12 strikes the nail 78 supported by the injection unit 32.

[0020] Furthermore, an electric motor 15 is located inside the motor case 21. The electric motor 15 has a rotor 39 and a stator 40 as shown in Figure 3. The stator 40 is attached to the motor case 21. The rotor 39 is rotatably supported by the motor case 21 via bearings (not shown). The electric motor 15 is, for example, a brushless motor, and when voltage is applied to the electric motor 15, the rotor 39 rotates about the center line A2.

[0021] Furthermore, a reduction mechanism (not shown) is provided inside the motor case 21. This reduction mechanism comprises multiple sets of planetary gear mechanisms. A rotating shaft 46 is provided inside the cylindrical section 33. The rotating shaft 46 and the reduction mechanism are arranged concentrically with respect to the center line A2. The reduction mechanism is located in the power transmission path from the electric motor 15 to the rotating shaft 46 and is a mechanism that reduces the rotation of the rotor 39 of the electric motor 15 and transmits it to the hoisting mechanism 17. The hoisting mechanism 17 is a mechanism that converts the rotational force of the rotating shaft 46 into a force that biases the striking section 12 in the return direction D2.

[0022] The driving machine 10 is also equipped with a trigger (operating unit) 75 and a trigger switch 109 (see Figure 3). The trigger 75 and trigger switch 109 are located on the handle 20. The trigger switch 109 detects whether or not an operating force is applied to the trigger 75 and outputs a signal according to the detection result.

[0023] The power supply unit 14 includes a housing case 76 and a battery housed within the housing case 76. The battery has a plurality of battery cells. These battery cells are rechargeable and dischargeable secondary batteries, and any known battery cells such as lithium-ion batteries, nickel-metal hydride batteries, lithium-ion polymer batteries, and nickel-cadmium batteries can be used.

[0024] The nail driving machine 10 is also provided with a magazine 77. The magazine 77 is supported by an injection unit 32 and a mounting unit 22. Nails (fasteners) 78 are housed inside the magazine 77. The magazine 77 has a feeder, which feeds the nails 78 inside the magazine 77 to the injection path 37. That is, the feeder moves the nails 78 inside the magazine 77 forward in the front-rear direction N1. The injection unit 32 is made of metal or synthetic resin. A push lever 79 is attached to the injection unit 32. The push lever 79 is an operating unit that can be operated within a predetermined range in the direction along the center line A1 relative to the injection unit 32. An elastic member (not shown) is provided to bias the push lever 79 in the direction along the center line A1. The elastic member is, for example, a metal spring, which biases the push lever 79 in a direction away from the bumper support unit 31.

[0025] Next, the control unit 82 shown in Figure 3, which is included in the driving machine 10, will be described. The control unit 82 is located within the mounting section 22 and mainly controls the drive of the electric motor 15. An inverter circuit 110 is also connected to the control unit 82. The inverter circuit 110 connects and disconnects the stator 40 of the electric motor 15 and the power supply unit 14. The inverter circuit 110 is equipped with multiple switching elements Q1, Q2, Q3, Q4, Q5, and Q6, and each of the multiple switching elements Q1, Q2, Q3, Q4, Q5, and Q6 can be turned on or off. The control unit 82 controls the inverter circuit 110 via the control signal output circuit 103, thereby controlling the rotation and stopping of the electric motor 15, or the rotation speed and rotation direction of the electric motor 15.

[0026] Furthermore, the driving machine 10 has, as input elements that transmit signals to the control unit 82, a blade detector switch 80a for detecting the position of the driver blade 29, a current detection circuit 100, a rotor 39 rotation position detection circuit 101, a power switch 102, and a power switch circuit 102a. The blade detector switch 80a is connected to the control unit 82 via a blade detector switch operation detection circuit 80b, the rotation position detection circuit 101 is connected to the control unit 82 via a rotation speed detection circuit 101d, and the power switch circuit 102a is connected to the control unit 82 via a power voltage supply circuit 105.

[0027] Furthermore, other input elements that transmit signals to the control unit 82 include a mis-engagement release switch 81 for releasing mis-engagement between the driver blade 29 and the pinwheel (rotating part) 50 (described later), a nail remaining amount switch 107 for detecting the remaining amount of nails 78, a voltage detection circuit 106, a push lever switch 108, and a trigger switch 109. The mis-engagement release switch 81 is connected to the control unit 82 via a mis-engagement release switch operation detection circuit 81a. The mis-engagement release switch 81 is installed on an operation panel 72 provided on the mounting part 22 of the housing 11 of the nail driver 10, as shown in Figure 1. The nail remaining amount switch 107 is connected to the control unit 82 via a nail remaining amount switch operation detection circuit 107a. The push lever switch 108 is connected to the control unit 82 via a push lever switch operation detection circuit 108a, and the trigger switch 109 is connected to the control unit 82 via a trigger switch operation detection circuit 109a.

[0028] The push lever (operating part) 79 shown in Figure 1 can be switched ON and OFF by being pressed against the workpiece 30 by the operator. The push lever switch 108 turns ON and outputs a signal when, for example, the push lever 79 is pressed against the workpiece 30. The trigger switch 109 also outputs a signal when the trigger (operating part) 75 on the handle 20 is operated by the operator, causing the trigger switch 109 to turn ON. The rotational position detection circuit 101 detects the rotational position of the rotor 39 using rotational position detection elements 101a, 101b, and 101c, which are Hall ICs, and outputs a signal.

[0029] The control unit 82 then processes the signals transmitted from the rotation position detection circuit 101, the blade detector switch 80a, the push lever switch 108, and the trigger switch 109, and controls the inverter circuit 110. As a result, the control unit 82 controls the stopping, rotation, rotation direction, and rotation speed of the electric motor 15.

[0030] Next, the winding mechanism 17 of the driving machine 10 will be described. As shown in Figure 2, the winding mechanism 17 includes a driver blade 29, a plurality of striking-side engaging parts provided on the driver blade 29, a pin wheel (rotating part) 50, and a plurality of rotating-side engaging parts provided on the pin wheel 50. The plurality of striking-side engaging parts and the plurality of rotating-side engaging parts are engageable with each other. In a plane perpendicular to the center line A1, the cross-sectional shape of the driver blade 29 is approximately rectangular. The driver blade 29 is provided with a plurality of striking-side engaging parts, namely racks 61, 62, 63, 64, 65, 66, 67, 68, 69, and 70. These racks 61, 62, 63, 64, 65, 66, 67, 68, 69, and 70 are provided integrally with the driver blade 29.

[0031] Furthermore, racks 61, 62, 63, 64, 65, 66, 67, 68, 69, and 70 are positioned between the tip 29a of the driver blade 29 in the direction along the centerline A1 and the piston 28. Also, racks 61, 62, 63, 64, 65, 66, 67, 68, 69, and 70 are arranged in the vertical direction M1 and are positioned in this order in the direction along the centerline A1. In the driving machine 10 of this embodiment, racks 61, 62, 63, 64, 65, 66, 67, 68, 69, and 70 are projections provided on the edge of the driver blade 29.

[0032] Then, when the striking unit 12 operates in the return direction D2 shown in Figure 2, rack 61 is positioned first, or the first, among the multiple racks in the return direction D2. When the striking unit 12 operates in the return direction D2, racks 62, 63, 64, 65, 66, 67, 68, 69, and 70 are positioned behind rack 61.

[0033] Furthermore, the driver blade 29 is provided with ribs 29c on the side surface of the blade body 29b. The ribs 29c are provided on the blade body 29b along the vertical direction M1 of the driver blade 29. The ribs 29c are also provided extending upward from the tip 29a of the blade body 29b to a predetermined height, and protrude in a direction that forms a 90° angle with the protruding direction of each rack. The ribs 29c are provided so as to be able to engage with the blade detector switch 80a provided on the nose portion 13. Specifically, the driver blade 29 and the blade detector switch 80a are positioned such that, during the vertical movement of the driver blade 29 in the vertical direction M1, the driver blade 29 and the blade detector switch 80a engage within a predetermined range.

[0034] As a result, the control unit 82 processes the on / off signals of the blade detector switch 80a due to the engagement of the rib 29c of the driver blade 29 with the blade detector switch 80a, thereby detecting the position of the striking section 12, including the driver blade 29, in the direction of the centerline A1.

[0035] Meanwhile, the pinwheel 50 is attached to the rotating shaft 46. The pinwheel 50 is a rotating part that rotates by the driving force of the electric motor 15. The pinwheel 50 can engage with the striking part 12 and can also be disengaged from the striking part 12. The pinwheel 50 is made of metal, non-ferrous metal, or steel, for example. The pinwheel 50 rotates about a center line A2. The center line A2 is positioned in a direction intersecting the operating direction of the striking part 12 and spaced apart from the driver blade 29 in the left-right direction R1.

[0036] The pinwheel 50 has a plurality of rotating-side engaging parts arranged in the rotation direction E1. As an example of the plurality of rotating-side engaging parts, 10 pins 51, 52, 53, 54, 55, 56, 57, 58, 59, 60 are provided on the pinwheel 50. The pins 51, 52, 53, 54, 55, 56, 57, 58, 59, 60 are provided separately from the pinwheel 50 and are fixed so as to protrude from the disc surface of the pinwheel 50. Furthermore, the pins 51, 52, 53, 54, 55, 56, 57, 58, 59, 60 are arranged on the same circumference centered on the center line A2.

[0037] Furthermore, the pinwheel 50 has a notch 50a formed in a second region at a predetermined angle in the rotation direction E1 of the pinwheel 50. For example, the notch 50a is formed in a region of 90°. The minimum outer diameter of the notch 50a centered on the center line A2 is smaller than the maximum outer diameter of the first region where the notch 50a is not formed. The first region where the notch 50a is not formed is a region of approximately 270° in the rotation direction E1 of the pinwheel 50.

[0038] Furthermore, the pins 51, 52, 53, 54, 55, 56, 57, 58, 59, and 60 of the pin wheel 50 and the racks 61, 62, 63, 64, 65, 66, 67, 68, 69, and 70 of the driver blade 29 are positioned to overlap in the direction along the center line A2, and are in a positional relationship that allows them to engage with each other.

[0039] Furthermore, the pinwheel 50 rotates counterclockwise due to the rotational force of the electric motor 15. In the pinwheel 50 of this embodiment, as an example, pin 51 is located in the second region in the rotation direction E1 of the pinwheel 50, and pins 52, 53, 54, 55, 56, 57, 58, 59, and 60 are located in the first region in the rotation direction E1 of the pinwheel 50. The pins 52, 53, 54, 55, 56, 57, 58, 59, and 60 are arranged in this order along the rotation direction E1 of the pinwheel 50. Pin 51 is located at the front, i.e., first, in the rotation direction E1 during one rotation of the pinwheel 50.

[0040] Furthermore, in the rotation direction E1 of the pinwheel 50, pins 52, 53, 54, 55, 56, 57, 58, 59, and 60 are located behind pin 51. Therefore, when the pinwheel 50 rotates while the striking unit 12 is stationary, of the multiple pins, pin 51 is the first to approach the operating area of ​​the driver blade 29 in the rotation direction E1 of the pinwheel 50.

[0041] In the driving machine 10, the rotational position, which is the position of the pin wheel 50 in the rotational direction E1, is detected by rotational position detection elements 101a, 101b, and 101c, which are Hall ICs that detect the position of the rotor 39 in the rotational direction E1. The driving machine 10 also includes a striking section position detection unit 80 that detects the striking section position, which is the position of the striking section 12 in the vertical direction M1. The striking section position detection unit 80 includes a blade detector switch 80a that can come into contact with the driver blade 29 of the striking section 12.

[0042] Then, as the pinwheel 50 rotates while the striking part 12 is engaged with it, the striking part 12 moves from its standby position to the other (upward) side in the vertical direction M1. On the other hand, when the striking part 12 is released from engagement with the pinwheel 50, it moves to the other (downward) side in the vertical direction M1 due to the pressure (biasing force) from the pressure chamber 26, thereby striking the nail 78. In other words, as the pinwheel 50 rotates under the driving force of the electric motor 15 while engaged with the striking part 12, it moves the striking part 12 upward in the vertical direction M1 against the biasing force of the pressure chamber 26, and when the engagement with the striking part 12 is released, the striking part 12 moves downward in the vertical direction M1 to its bottom dead center due to the biasing force of the pressure chamber 26.

[0043] Furthermore, the pinwheel 50 can switch between multiple states, including an engageable state in which it can engage with the striking section 12 and an unengageable state in which it cannot engage with the striking section 12, by the rotation of the pinwheel 50. The control unit 82 then performs brake control by applying braking force to the electric motor 15, thereby releasing the engagement of the pinwheel 50 with the striking section 12, causing the striking section 12 to move downward in the vertical direction M1 to its bottom dead center, and then maintaining the pinwheel 50 in the unengageable state for a predetermined time.

[0044] The striking unit 12, having moved to the bottom dead center, performs a driving operation. At this time, the control unit 82 determines whether the driving operation by the striking unit 12 is a first driving operation in which all of the multiple pins engage with the rack of the driver blade 29 (in a predetermined engagement relationship), or a second driving operation in which some of the multiple pins do not engage with the rack of the driver blade 29 (not in a predetermined engagement relationship), based on the rotational position of the pin wheel 50 and the striking unit position of the striking unit 12. The first driving operation is a normal driving operation in which no mis-engagement occurs between the striking unit 12 and the pin wheel 50. On the other hand, the second driving operation is a driving operation in which mis-engagement occurs between the striking unit 12 and the pin wheel 50. In other words, the driving machine 10 detects the positions of the striking unit 12 and the pin wheel 50, and the control unit 82 determines whether or not mis-engagement occurs between the striking unit 12 and the pin wheel 50. The above determination is performed by counting the rotational position detection element, which is a Hall IC.

[0045] Furthermore, the mis-engagement release switch 81 installed on the control panel 72 of the driving machine 10 is a switch that, when a mis-engagement occurs in the engagement between the striking section 12 and the pin wheel 50, is operated by the operator with the push lever 79 and trigger 75 turned ON, respectively, to start the reverse rotation of the pin wheel 50.

[0046] Specifically, when the operator switches the operation of the electric motor 15 to rotation using the push lever 79 and trigger 75, the operator operates the mis-engagement release switch 81, which causes the pin wheel 50 to start reversing. In other words, by operating the mis-engagement release switch 81, the operator can reverse the rotation of the pin wheel 50 (rotating in the opposite direction to the rotation direction E1) and release the mis-engagement between the striking part 12 and the pin wheel 50.

[0047] Next, the driving control of the driving machine 10 in this embodiment will be described.

[0048] The control unit 82 has two control modes for controlling the drive of the electric motor 15: a single-shot mode and a continuous-shot mode. In single-shot mode, the push lever 79 is first turned ON, and each time the trigger 75 is turned ON in this state, a shot is taken. In single-shot mode, the electric motor 15 stops when the shot is finished (even if the trigger 75 is turned ON before the electric motor 15 stops, the ON operation of the trigger 75 is ignored).

[0049] In contrast, the continuous firing mode is a mode in which the trigger 75 is first turned on, and each time the push lever 79 is turned on in this state, a hammering operation is performed. In continuous firing mode, if the push lever 79 is turned on again before the electric motor 15 stops, the electric motor 15 will not stop and will perform the next hammering operation. The hammering machine 10 is provided with a mode switching button (not shown), and the operator can switch the control mode of the control unit 82 by operating the mode switching button.

[0050] First, we will explain the driving control of the driving machine 10 using the continuous firing mode with reference to Figures 1 to 9.

[0051] When the control unit 82 detects that the push lever 79 is pressed against the mating material 30 with an operating force applied to the trigger 75, it applies voltage from the power supply unit 14 to the electric motor 15, causing the electric motor 15 to rotate in the forward direction. This starts the driving operation. When the electric motor 15 rotates in the forward direction, the rotational force of the electric motor 15 is transmitted to the rotating shaft 46 via a reduction mechanism (not shown). Then, the rotating shaft 46 and the pin wheel 50 begin to rotate counterclockwise (rotation direction E1) in Figure 2. This causes the striking part 12 (driver blade 29) to rise. As the striking part 12 rises, the gas pressure in the pressure chamber 26 increases. The raised striking part 12 reaches its top dead center. Then, when the last pin 60 in the rotation direction E1 of the pin wheel 50 separates from the last rack 70, the striking part 12 descends due to the gas pressure in the pressure chamber 26. In other words, the top dead center is the position of the striking part 12 when the pin 60 is separated from the rack 70. As the striking part 12 descends, the driver blade 29 strikes a single nail 78 located in the ejection path 37, and the nail 78 is driven into the mating material 30.

[0052] After the nail 78 is driven into the mating material 30, the piston 28 collides with the bumper 35, and the striking part 12 reaches its bottom dead center.

[0053] The control unit 82 continues to rotate the electric motor 15 even after the striking unit 12 has driven in the nail 78 and reached the bottom dead center. As a result, the pin wheel 50 rotates counterclockwise (rotation direction E1) as shown in Figure 2, and the pin 51 approaches the rack 61.

[0054] Then, when the pin 51 engages with the rack 61, the striking part 12 begins to move (rise) from the bottom dead center to the top dead center due to the rotational force of the pin wheel 50. As the striking part 12 rises towards the top dead center, it reaches the sensor reaction position L1 shown in Figure 4 (see Figure 6). At this point, the blade detector switch 80a begins to engage with the rib 29c of the driver blade 29.

[0055] Here, the blade detector switch 80a will be described. The blade detector switch 80a is a striking part position detection unit 80 that detects the position of the driver blade 29 (striking part 12) by contacting the driver blade 29. When the striking part position detection unit 80 detects the position of the driver blade 29, it sends a detection signal to the control unit 82. The blade detector switch 80a has a projection 80d at its tip, and a magnet 80e is provided at the end opposite the projection 80d. The projection 80d can engage with the rib 29c of the driver blade 29. The blade detector switch 80a is mounted to rotate by a rotating shaft 80c provided between the projection 80d and the magnet 80e.

[0056] Meanwhile, a Hall IC 80f for detecting the magnet 80e of the blade detector switch 80a is provided on the blade guide 34 (see Figure 2). The blade detector switch 80a is biased by a torsion spring (not shown) so that its protrusion 80d always faces the driver blade 29. When the protrusion 80d engages with the rib 29c of the driver blade 29, the blade detector switch 80a rotates around the rotation axis 80c, separating the magnet 80e and the Hall IC 80f, and the Hall IC 80f stops detecting the magnet 80e. When the Hall IC 80f stops detecting the magnet 80e, the striking position detection unit 80 detects the position of the driver blade 29 and sends a detection signal to the control unit 82.

[0057] Furthermore, when the engagement between the protrusion 80d of the blade detector switch 80a and the rib 29c of the driver blade 29 is released, the protrusion 80d is biased toward the driver blade 29, causing the Hall IC 80f of the blade detector switch 80a to detect the magnet 80e.

[0058] When the driver blade 29 (striking part 12) reaches the sensor reaction position L1 shown in Figure 6, the protrusion 80d of the blade detector switch 80a engages with the rib 29c of the driver blade 29. When the protrusion 80d and the rib 29c of the driver blade 29 engage, the Hall IC 80f stops detecting the magnet 80e (sensor reaction), as described above, and the blade detector switch 80a (striking part position detection unit 80) detects the position of the driver blade 29 and sends a detection signal (Low signal) to the control unit 82.

[0059] When the control unit 82 receives a detection signal (Low signal) from the blade detector switch 80a, it performs brake control to apply braking force to the electric motor 15. That is, when the striking unit 12 reaches a predetermined position while moving upward in the vertical direction M1, the control unit 82 performs brake control to the electric motor 15 (times T1, T2, T3). Here, the predetermined position is the position where the blade detector switch 80a begins to engage with the rib 29c of the driver blade 29 as the driver blade 29 (striking unit 12) rises toward the top dead center. Alternatively, the predetermined position is the position of the driver blade 29 when the blade detector switch 80a (striking unit position detection unit 80) detects the position of the driver blade 29 and sends a detection signal (Low signal) to the control unit 82, which is the sensor reaction position L1 shown in Figure 4.

[0060] In other words, when the striking portion 12 is in the predetermined position, the protruding portion 80d of the blade detector switch 80a contacts the rib 23b of the driver blade 29, and the striking portion position detection unit 80 detects the position of the driver blade 29 (striking portion 12).

[0061] Furthermore, as shown in Figure 5, the control unit 82 reduces the operating voltage applied to the electric motor 15 while the driver blade 29 is positioned above the predetermined position in the vertical direction M1 to a lower value than the operating voltage applied while the driver blade 29 is positioned below the predetermined position in the vertical direction M1. That is, the duty cycle of the operating voltage applied to the electric motor 15 while the driver blade 29 is positioned above the predetermined position is reduced to a lower value than the duty cycle of the operating voltage applied while the driver blade 29 is positioned below the predetermined position. For example, the duty cycle of the operating voltage while the driver blade 29 is positioned below the predetermined position is 100%, and the duty cycle of the operating voltage while the driver blade 29 is positioned above the predetermined position is 70% to 80%. The control unit 82 can sufficiently reduce the speed of the pinwheel 50 by setting the duty cycle of the operating voltage while the driver blade 29 (striking part 12) is located above the predetermined position in the vertical direction M1 to 60% or more and less than 90% of the duty cycle of the operating voltage while the driver blade 29 (striking part 12) is located below the predetermined position in the vertical direction M1.

[0062] While the driver blade 29 is positioned above the predetermined position, the duty cycle of the operating voltage applied to the electric motor 15 is reduced to 60% or more and less than 90%.

[0063] Next, as shown in Figure 7, the driver blade 29 (striking section 12) rises upward in direction B1 as its final rack 70 is pushed up by the final pin 60 of the pinwheel 50, reaching top dead center P1. At this time, the blade detector switch 80a is engaged with the rib 29c of the driver blade 29, and therefore sends a detection signal (Low signal shown in Figure 4) to the control unit 82.

[0064] Then, when the engagement between the final pin 60 of the pinwheel 50 and the final rack 70 of the driver blade 29 is released, the driver blade 29 is released and descends toward the bottom dead center. As the driver blade 29 moves from the top dead center to the bottom dead center, when the engagement between the projection 80d of the blade detector switch 80a and the rib 29c of the driver blade 29 is released, the projection 80d is biased toward the driver blade 29, causing the Hall IC 80f of the blade detector switch 80a to detect the magnet 80e.

[0065] As a result, the signal sent from the blade detector switch 80a to the control unit 82 switches from a Low signal to a High signal.

[0066] Subsequently, as shown in Figure 8, the driver blade 29 descends in the downward direction C1, striking the nail 78 (see Figure 2) and reaching the bottom dead center S1. At this time, the piston 28 collides with the bumper 35 shown in Figure 2, causing the driver blade 29 (striking part 12) to bounce. Meanwhile, in the pinwheel 50, the electric motor 15 is brake-controlled. Also, as shown in Figure 5, the duty cycle of the operating voltage applied to the electric motor 15 is reduced. As a result, as shown in Figure 4, the rotational speed of the electric motor 15 is also reduced, and the pinwheel 50 rotates at a slower speed. Therefore, even though the driver blade 29 bounces, the pinwheel 50 is rotating slowly, and the first pin 51 of the pinwheel 50 has not yet approached the driver blade 29. This makes it possible to avoid a collision between the driver blade 29 and the first pin 51 of the pinwheel 50.

[0067] Subsequently, the control unit 82 releases the brake control of the electric motor 15. Then, as shown in Figure 5, the duty cycle of the operating voltage applied to the electric motor 15 is gradually increased, and as shown in Figure 4, the rotational speed of the electric motor 15 is gradually increased, performing the re-hoisting U1 shown in Figure 9. That is, the first pin 51 of the pinwheel 50 engages with the first rack 61 of the driver blade 29, and the pinwheel 50 begins to push up the driver blade 29. Once re-hoisting U1 is started, the rotational speed of the electric motor 15 decreases due to the load that the pinwheel 50 receives from the driver blade 29.

[0068] Furthermore, the first control is defined as the control to rotate the pinwheel 50 at a first rotational speed while the driver blade 29 (striking part 12) is positioned below the predetermined position, and the second control is defined as the control to rotate the pinwheel 50 at a second rotational speed smaller than the first rotational speed while the driver blade 29 (striking part 12) is positioned above the predetermined position. In this case, the control unit 82 is capable of executing multiple controls, including the first and second controls, and switches the control of the rotational speed of the pinwheel 50 based on the detection result of the blade detector switch 80a (striking part position detection unit 80).

[0069] The blade detector switch 80a (striking position detection unit 80) sends a detection signal (Low signal) to the control unit when the driver blade 29 is located in the detection area between the predetermined position and the bottom dead center S1.

[0070] Furthermore, when the push lever 79 and trigger 75 are operated while the control unit 82 is in standby mode, the control unit 82 drives the electric motor 15 to move the driver blade 29 (striking part 12) upward in the vertical direction M1. Then, the engagement between the driver blade 29 and the pin wheel 50 is released at top dead center P1, and the driver blade 29 moves downward in the vertical direction M1 to bottom dead center S1. After the driver blade 29 has moved to bottom dead center S1, it moves upward in the vertical direction M1 and, when it is positioned above the predetermined position in the vertical direction M1, the control unit 82 stops the electric motor 15 again (performs brake control of the electric motor 15) and returns to standby mode.

[0071] In detail, the control unit 82 stops the electric motor 15 again (performs brake control of the electric motor 15) after the driver blade 29 (striking part 12) has moved downward in the vertical direction M1 to the bottom dead center S1, then moved upward in the vertical direction M1, and after a predetermined time has elapsed since it is positioned above the predetermined position in the vertical direction M1.

[0072] Next, the single-shot driving control of the driving machine 10 will be explained using Figures 10 to 16. When the control unit 82 detects that operating force is applied to the trigger 75 and that the push lever 79 is pressed against the mating material 30, it applies voltage from the power supply unit 14 to the electric motor 15, causing the electric motor 15 to rotate in the forward direction. This starts the driving operation. When the electric motor 15 rotates in the forward direction, the rotational force of the electric motor 15 is transmitted to the rotating shaft 46 via a reduction mechanism (not shown). Then, the rotating shaft 46 and the pin wheel 50 begin to rotate counterclockwise (rotation direction E1) in Figure 2. This causes the striking part 12 (driver blade 29) to rise. When the striking part 12 rises, the gas pressure in the pressure chamber 26 increases. The raised driver blade 29 (striking section 12) is pushed upward in the direction B1 by the final rack 70 being pushed up by the final pin 60 of the pinwheel 50, and reaches the top dead center V1 shown in Figure 10 (see Figure 12). At this time, the blade detector switch 80a is engaged with the rib 29c of the driver blade 29, and therefore sends a detection signal (low signal) to the control unit 82.

[0073] Then, when the final pin 60 in the rotation direction E1 of the pinwheel 50 separates from the final rack 70, the striking part 12 descends due to the gas pressure in the pressure chamber 26. In other words, the position of the striking part 12 at the moment when the pin 60 separates from the rack 70 is the top dead center. As the driver blade 29 (striking part 12) descends in the downward direction C1, it strikes a single nail 78 (see Figure 2) located in the injection passage 37, and the nail 78 is driven into the mating material 30.

[0074] After the nail 78 is driven into the mating material 30, the piston 28 (striking part 12) collides with the bumper 35 and reaches the bottom dead center W1 shown in Figure 10 (see Figure 13). In the process of the driver blade 29 (striking part 12) reaching the bottom dead center S1, as shown in Figure 13, the engagement between the protrusion 80d of the blade detector switch 80a and the driver blade 29 is released, and the protrusion 80d is biased toward the driver blade 29, causing the Hall IC 80f of the blade detector switch 80a to detect the magnet 80e. As a result, as shown in Figure 10, the signal sent from the blade detector switch 80a to the control unit 82 switches from a Low signal to a High signal.

[0075] Furthermore, as shown in Figure 11, the duty cycle of the operating voltage applied to the electric motor 15 becomes 100% just before the signal sent from the blade detector switch 80a to the control unit 82 switches to a High signal.

[0076] Then, as shown in Figure 10, the rotational speed of the electric motor 15 is gradually increased, and when a predetermined rotational speed is reached, the re-winding X1 shown in Figure 14 occurs. That is, the first pin 51 of the pin wheel 50 engages with the first rack 61 of the driver blade 29, and the pin wheel 50 begins to push up the driver blade 29.

[0077] As the driver blade 29 (striking part 12) is pushed up and rises, when it reaches the sensor reaction position Y1 shown in Figure 15, the protrusion 80d of the blade detector switch 80a engages with the rib 29c of the driver blade 29. When the protrusion 80d and the rib 29c of the driver blade 29 engage, the Hall IC 80f stops detecting the magnet 80e (sensor reaction), as described above, and the blade detector switch 80a (striking part position detection unit 80) detects the position of the driver blade 29 and sends a detection signal (Low signal) to the control unit 82. That is, at time T4, the signal sent from the blade detector switch 80a to the control unit 82 switches from a High signal to a Low signal, and the driver blade 29 reaches the predetermined position.

[0078] Subsequently, the driver blade 29 reaches the standby position Z1 shown in Figure 10 (see Figure 16). That is, the control unit 82 executes control to stop the electric motor 15 after the driver blade 29 (striking part 12) has reached the predetermined position and a predetermined time has elapsed. As a result, as shown in Figure 11, when the duty cycle of the operating voltage applied to the electric motor 15 becomes 0%, the electric motor 15 also gradually decreases in rotational speed and then stops, and the rotation of the pin wheel 50 also stops.

[0079] As described above, in the single-shot mode of driving control, no brake control is performed to apply braking force to the electric motor 15.

[0080] In the driving machine 10 of this embodiment, in continuous firing mode, after the first firing, when the driver blade 29 (striking part 12) reaches a predetermined position just before reaching top dead center P1, the control unit 82 performs brake control to apply braking force to the electric motor 15. At this time, the predetermined position is the position of the driver blade 29 at the time when the blade detector switch 80a (striking part position detection unit 80) detects the position of the driver blade 29 and sends a detection signal (Low signal) to the control unit 82. When the control unit 82 performs brake control of the electric motor 15, the duty cycle of the operating voltage applied to the electric motor 15 decreases. Furthermore, immediately after the driver blade 29 is released at top dead center P1, the rotation speed of the pinwheel 50 temporarily decreases, and the rotation speed of the pinwheel 50 slows down.

[0081] In this state, the driver blade 29 drives the pin, and after driving, the piston 28 collides with the bumper 35, causing the striking part 12 to reach bottom dead center S1. When the piston 28 collides with the bumper 35, the driver blade 29 bounces. At this time, the rotational speed of the pinwheel 50 is temporarily slowed down, so a collision between the first pin 51 of the pinwheel 50 and the first rack 61 of the driver blade 29 can be avoided. In other words, even if the driver blade 29 bounces, a collision between the driver blade 29 and the first pin 51 of the pinwheel 50 can be avoided. To put it another way, after the driver blade 29 is released at top dead center and has moved to bottom dead center, the pinwheel 50 can be kept in a state of disengagement from the driver blade 29 for a predetermined time. This makes it possible to avoid a collision between the driver blade 29 and the first pin 51 of the pinwheel 50 even if the driver blade 29 bounces.

[0082] In other words, since collisions between the driver blade 29 and the pin wheel 50 can be avoided, collisions between the driver blade 29 and the pin wheel 50 can be suppressed, improving the convenience of the driving machine 10.

[0083] Furthermore, by detecting the position of the driver blade 29 (striking part 12) using the blade detector switch 80a (striking part position detection unit 80) and sending a detection signal to the control unit 82, it is possible to detect with high accuracy a predetermined position just before the driver blade 29 reaches the top dead center and a predetermined position in the region between the top dead center and the bottom dead center as the driver blade 29 descends.

[0084] Therefore, by detecting with high precision the timing for starting and releasing brake control of the electric motor 15, the control unit 82 can switch the control of the rotation speed of the pin wheel 50 with high precision. For example, if the control unit 82 determines that the duty cycle of the operating voltage applied to the electric motor 15 has not reached 100% at the timing when the blade detector switch 80a in Figure 5 switches from a Low signal to a High signal, it may be configured to immediately switch the control mode to first control and raise the duty cycle. With such a configuration, the time required for one cycle of driving operation can be shortened by increasing the rotation speed of the electric motor 15. Note that there is a time lag between when the duty cycle of the electric motor 15 is raised and when the rotation speed actually increases, so even if the duty cycle is raised at the timing when the blade detector switch 80a switches from a Low signal to a High signal, it is possible to avoid the first pin 51 colliding with the bouncing driver blade 29.

[0085] The present invention is not limited to the embodiments described above, and can be modified in various ways without departing from its spirit. [Explanation of Symbols]

[0086] 10...Drilling machine (working machine), 11...Housing, 12...Impact section, 13...Nose section, 14...Power supply section, 15...Electric motor (drive section), 17...Winding mechanism, 18...Pressure accumulator, 19...Cylinder case, 20...Handle, 21...Motor case, 22...Mounting section, 23...Cap, 24...Holder, 25...Head cover, 26...Pressure chamber (biasing section), 27...Cylinder, 28...Piston, 29...Driver blade, 29a...Tip, 29b...Blade body, 29c...Rib, 30...Mating material, 31...Bumper support section, 32...Injection section, 33...Cylinder section, 34 ...blade guide, 35...bumper, 36...guide hole, 37...ejection path, 39...rotor, 40...stator, 46...rotating shaft, 50...pinwheel (rotating part), 50a...notch, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60...pin, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70...rack, 72...operating panel, 75...trigger (operating part), 76...storage case, 77...magazine, 78...nail (fastener), 79...push lever (operating part), 80...striking part position detection part, 80a...blade detector switch 80b…Blade detector switch operation detection circuit, 80c…Rotation shaft, 80d…Protrusion, 80e…Magnet, 80f…Hall IC, 81…Release switch, 81a…Release switch operation detection circuit, 82…Control unit, 84…Sealing member, 100…Current detection circuit, 101…Rotation position detection circuit, 101a, 101b, 101c…Rotation position detection element, 101d…Rotation speed detection circuit, 102…Power switch, 102a…Power switch circuit, 103…Control signal output circuit, 105…Power supply voltage supply circuit, 106…Voltage detection circuit, 1 07... Nail remaining amount switch, 107a... Nail remaining amount switch operation detection circuit, 108... Push lever switch, 108a... Push lever switch operation detection circuit, 109... Trigger switch, 109a... Trigger switch operation detection circuit, 110... Inverter circuit, A1, A2... Center line, B1... Upward direction, C1... Downward direction, D1... Driving direction, D2... Return direction, E1... Rotation direction, M1... Up / down direction (first direction), N1... Front / back direction, Q1, Q2, Q3, Q4, Q5, Q6... Switching element, R1... Left / right direction, T1, T2, T3, T4... Time

Claims

1. Injection section and A striking part that moves to one side in the first direction to strike the stopper supported by the injection part, A biasing unit that biases the striking unit toward one side in the first direction, The drive unit and A rotating part, which rotates by receiving the driving force of the drive part while engaged with the striking part, thereby moving the striking part to the other side of the first direction against the biasing force of the biasing part, and by disengaging from the striking part, moves the striking part to the bottom dead center on one side of the first direction by the biasing force of the biasing part, It includes a control unit that controls the drive of the drive unit, The rotating part can be switched between multiple states, including an engageable state in which it can engage with the striking part, and an unengageable state in which it cannot engage with the striking part, by the rotation of the rotating part. The control unit performs brake control to apply braking force to the drive unit, thereby disengaging the rotating unit from the striking unit, causing the striking unit to move to one side in the first direction and reach the bottom dead center, after which the rotating unit is maintained in the disengaged state for a predetermined time.

2. The work machine according to claim 1, wherein the control unit performs the brake control when the striking part reaches a predetermined position while moving toward the other side in the first direction.

3. The work machine according to claim 2, further comprising a striking part position detection unit that detects the position of the striking part by contacting the striking part when the striking part is located in the predetermined position.

4. The work machine according to claim 3, wherein the striking part position detection unit sends a detection signal to the control unit when the striking part is located in a detection area between the predetermined position and the bottom dead center.

5. It has an operating unit that is operated by the operator, The control unit, When the operating unit is operated in the standby state, the drive unit is driven so that the striking unit moves to the other side in the first direction. The work machine according to claim 2, wherein when the engagement between the striking part and the rotating part is released, the striking part moves to the bottom dead center on one side in the first direction, then moves to the other side in the first direction, and when it is positioned on the other side in the first direction beyond the predetermined position, the drive unit is stopped again and the machine enters a standby state.

6. The work machine according to claim 5, wherein the control unit stops the drive unit again after a predetermined time has elapsed since the striking unit moved to the bottom dead center on one side in the first direction, and then moved to the other side in the first direction, and is positioned on the other side in the first direction from the predetermined position.

7. The work machine according to claim 2, wherein the control unit reduces the operating voltage applied to the drive unit while the striking unit is located on the other side of the first direction from the predetermined position to the operating voltage applied while the striking unit is located on one side of the first direction from the predetermined position to the predetermined position.

8. The work machine according to claim 7, wherein the control unit sets the operating voltage while the striking portion is located on the other side of the first direction from the predetermined position to 60% or more and less than 90% of the operating voltage while the striking portion is located on one side of the first direction from the predetermined position.

9. Injection section and A striking part that moves to one side in the first direction to strike the stopper supported by the injection part, A biasing unit that biases the striking unit toward one side in the first direction, The drive unit and A rotating part, which rotates by receiving the driving force of the drive part while engaged with the striking part, thereby moving the striking part to the other side of the first direction against the biasing force of the biasing part, and by disengaging from the striking part, moves the striking part to the bottom dead center on one side of the first direction by the biasing force of the biasing part, A control unit that controls the drive of the rotating part, It includes a striking part position detection unit that detects the position of the striking part by contacting the striking part, The control unit is capable of executing a plurality of controls, including a first control that rotates the rotating part at a first rotational speed and a second control that rotates the rotating part at a second rotational speed smaller than the first rotational speed, and switches the rotational speed control based on the detection result of the striking part position detection unit.

Images