Work machine
Patent Information
- Application Number
- JP2025543472
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Filing Date
- 2026-02-26
- Publication Date
- 2026-05-26
Abstract
Description
Work equipment
[0001] The present invention relates to a work machine.
[0002] The fastener driving machine described in Patent Document 1 has a support section to which fasteners are fed, an impact section that strikes the fasteners on the support section, a moving mechanism that receives power from a power supply section and moves the impact section, a feeder that feeds the fasteners to the support section, and a moving section that receives power from the power supply section and moves the feeder.
[0003] Patent No. 7081595
[0004] In a work machine in which the feeder and impact unit are driven by power supplied from a common power supply unit, if power is consumed to drive the feeder, the driving speed of the impact unit will decrease, which will increase the time required to strike the stopper, and this may reduce the convenience of the work machine.
[0005] An object of the present invention is to provide a work machine with improved convenience.
[0006] In one embodiment, the work machine includes a feeder that delivers fasteners from a magazine, an impact unit that impacts the fasteners delivered by the feeder, a first drive unit that drives the impact unit, a second drive unit that drives the feeder, a power supply unit that supplies power to the first drive unit and the second drive unit, and a control unit that controls the effective value of the voltage supplied to at least one of the first drive unit and the second drive unit in accordance with the available power that can be supplied from the power supply unit to the first drive unit and the second drive unit, and the control unit changes the effective value of the voltage supplied to the first drive unit in accordance with the available power.
[0007] According to the present invention, the convenience of the work machine can be improved.
[0008] 4 is a right side view showing the appearance of the nail driver of the present embodiment; FIG. 5 is a right side view showing a part of the internal structure of the nail driver of FIG. 1; FIG. 6 is a bottom view showing the internal structure of the nail driver of FIG. 1 when the driver blade is at top dead center; FIG. 7 is an explanatory view showing a state immediately before the feeder of the nail driver of FIG. 1 supplies nails in the supply passage to a support part; FIG. 8 is an explanatory view showing a state immediately after the feeder of FIG. 4 supplies nails in the supply passage to a support part; FIG. 9 is a circuit block diagram showing each component of the nail driver of FIG. 1; FIG. 10 is a table showing the available power, effective voltage value, and target current value set in the control unit of the nail driver of FIG. 1; FIG. 11 is a flowchart showing each process executed in the nail driver of FIG. 1; FIG. 12 is a graph showing the set duty, effective current value, and operating position of the motor and solenoid in the nail driver of FIG. 1, together with a comparative example; FIG. 13 is a graph showing the set duty, effective current value, and operating position of the motor and solenoid in a nail driver of a modified example of the present embodiment, together with a comparative example.
[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that in all drawings referred to for describing the embodiments, the same reference numerals are used for identical or substantially identical configurations and elements. Furthermore, as a general rule, configurations and elements that have already been described will not be described repeatedly.
[0010] [Configuration of the Nail Driver] Fig. 1 shows a nail driver 10 that drives a nail N (Fig. 4) into a mating material G as an example of a work machine according to this embodiment. The nail N is an example of a fastener. When a predetermined condition is satisfied, the nail N is struck by a striking unit 76, which will be described later. As a result, the nail N is ejected from a support unit 42, which will be described later, and driven into the mating material G.
[0011] The nail gun 10 includes a housing 12 , a support unit 42 , a magazine 52 , a feeder 66 , a striking unit 76 , a first drive unit 84 , a battery 144 , and a control unit 150 .
[0012] As shown in FIG. 2 , the nail gun 10 further includes a switching unit 118 , a second driving unit 132 , a solenoid spring 136 , and a restricting member 142 .
[0013] <Definition of Directions> The direction in which the striking portion 76 shown in Fig. 1 strikes the nail N is defined as the second direction. As an example, the second direction refers to the direction from the top to the bottom in the vertical direction. In other words, the striking portion 76 strikes the nail N downward (toward the mating material G). The vertical direction, the front-rear direction, and the left-right direction are perpendicular to one another. Note that the definitions of the vertical direction, the front-rear direction, and the left-right direction are provided merely for the convenience of explanation.
[0014] As shown in FIG. 2 , the K direction is a direction that intersects both the up-down direction and the front-rear direction, and is the direction in which the feeder 66 moves back and forth. The K direction is indicated by the arrow K. In the K direction, the side where the magazine 52 is located is defined as one side, and the side where the support unit 42 is located is defined as the other side. On one side of the K direction, a plurality of nails N are stored in a drum unit 53 ( FIG. 1 ), which will be described later. As an example, the first direction is the direction from one side to the other side of the K direction. The feeder 66 supplies the nails N to the support unit 42 by moving to the other side of the K direction. The first direction and the second direction intersect with each other.
[0015] 1 is composed of two housing members made of synthetic resin such as nylon or polycarbonate. More specifically, the housing 12 is composed of two housing members that are butted against each other in the left-right direction and fixed with screws (not shown). As a result, each member is accommodated inside the housing 12.
[0016] The housing 12 has a cylinder portion 14, a motor accommodating portion 16, a handle portion 18, an extension portion 24, and an attachment portion 26. A support portion 42 is provided on the housing 12. Details of the support portion 42 will be described later. Furthermore, the housing 12 is provided with an operating portion 32 and an impact force generating portion 86.
[0017] The cylinder portion 14 extends in the vertical direction. The motor housing portion 16 extends rearward from the lower portion of the cylinder portion 14 in the front-to-rear direction. A striking portion 76 (described later) is provided inside the cylinder portion 14. The handle portion 18 extends diagonally upward from the center of the cylinder portion 14 rearward.
[0018] The extension portion 24 extends diagonally upward and rearward from the rear of the motor housing portion 16. The attachment portion 26 is connected to the rear end of the handle portion 18 and the rear end of the extension portion 24. A battery 144 (described later) is detachably attached to the attachment portion 26. A control portion 150 is provided inside the attachment portion 26.
[0019] <<Operation Unit>> The operation unit 32 is operated by the worker. The operation unit 32 has a trigger 34 and a trigger switch 36. When the trigger 34 is pressed upward by the worker, the trigger switch 36 sends an ON signal to the control unit 150. When the pressure on the trigger 34 is released (when the worker does not operate the trigger 34), the trigger switch 36 sends an OFF signal to the control unit 150. In this way, ON and OFF signals for the driving operation are output from the operation unit 32 to the control unit 150.
[0020] <Support Section> The support section 42 extends downward in the vertical direction from the lower end of the cylinder 88 of the cylinder section 14. An injection passage 46 is provided inside the support section 42. The support section 42 stores and supports the nails N (FIG. 4) supplied from the feeder 66. The feeder 66, which will be described later, supplies the nails N one by one from the magazine 52 to the injection passage 46. In the support section 42, the nail N receives the impact force from the striking section 76, and the nail N is injected toward the target material G.
[0021] The support portion 42 is provided with a rotation shaft 47 (FIG. 4) that extends in the vertical direction. Furthermore, the support portion 42 is provided with a push lever 48. The push lever 48 is held by the support portion 42 so that it can move in the vertical direction. The push lever 48 is also biased downward by a spring. When the push lever 48 is pressed against the mating material G, it moves upward against the biasing force of the spring. At this time, a predetermined signal is output to the control portion 150.
[0022] <Magazine> The magazine 52 is attached to the lower part of the housing 12 and to the rear side of the support part 42. The magazine 52 stores and supports a plurality of linked nails N in a roll shape. The plurality of nails N are linked together by a linking device M (Fig. 4) while supported by the magazine 52. The magazine 52 has a hollow drum part 53, a guide part 54 in which the plurality of nails N are aligned, and a lid part 56 (Fig. 4) facing the guide part 54 in the left-right direction.
[0023] The guide portion 54 extends forward from the drum portion 53 and is connected to the support portion 42. Some of the nails N are positioned in the guide portion 54 with their axial direction perpendicular to the K direction and are lined up along the K direction. A pin 65 ( FIG. 2 ) is provided in the guide portion 54. The pin 65 has a central axis along the left-right direction and protrudes from the guide portion 54 to the right.
[0024] As shown in Figure 4, a supply passage 58 is provided between the guide portion 54 and the lid portion 56. The supply passage 58 extends in the front-rear direction toward the injection passage 46. A plurality of nails N are aligned in the supply passage 58 and fed one by one into the injection passage 46. The lid portion 56 can open and close the supply passage 58 by rotating about the rotation shaft 47. A claw member 62 and a spring 64 are provided on the lid portion 56.
[0025] The claw member 62 has a base 62A that rotates around a rotation shaft 63 that extends in the vertical direction, a plate 62B that extends forward from the base 62A, and a claw 62C that protrudes from the plate 62B into the supply passage 58. The plate 62B is biased toward the supply passage 58 by a spring 64. The magazine 52, a feeder 66 (described later), and a second drive unit 132 are collectively referred to as the supply unit 60.
[0026] 2, the feeder 66 performs linear motion in the K direction. The feeder 66 moves from one side to the other in the K direction to move the nails N from the magazine 52 to the striking position of the support part 42 for the nails N. The feeder 66 biases the other nails N, among the multiple nails N, that are located on the other side (the magazine 52 side) of the nail N located at the end on the other side in the K direction, toward the other side in the K direction.
[0027] As shown in FIG. 4, the feeder 66 includes a movable member 68 , a feeding member 72 , and a spring 75 .
[0028] 4 and 5 , the movable member 68 has a fixed portion 68A fixed to a plunger 134B (described later), a contacted portion 68B ( FIG. 2 ) protruding rearward from the fixed portion 68A, and a shaft portion 68C extending in a direction perpendicular to the K direction. The fixed portion 68A can reciprocate in the K direction in conjunction with movement of the plunger 134B. The contacted portion 68B can come into contact with and separate from a regulating member 142 ( FIG. 2 ), described later.
[0029] <<Feeding Member>> The feeding member 72 is rotatable about the shaft 68C. The feeding member 72 has a first claw 72A and a second claw 72B. The first claw 72A and the second claw 72B protrude into the supply passage 58. The first claw 72A feeds the leading nail N to the other side in the K direction. The second claw 72B feeds the second nail N to the other side in the K direction. The nail N fed by the first claw 72A and the second claw 72B moves to the right along the slope of the claw 62C and passes over the claw 62C. The nail N that passes over the claw 62C is restricted from moving to one side in the K direction by the claw 62C. In this way, the nail N is prevented from returning to one side in the K direction after being fed into the support portion 42.
[0030] <<Spring>> The spring 75 is a torsion spring that is wound around the shaft portion 68 C. The spring 75 biases the feeding member 72 toward the supply passage 58 .
[0031] <Striking Section> As shown in Figure 1, the striking section 76 has a piston 78 and a driver blade 82. The striking section 76 strikes the nails N delivered by the feeder 66. The striking section 76 also strikes the nails N (Figure 4) located in the support section 42 towards the mating material G. The striking section 76 is capable of performing a first operation, a second operation, and a third operation, which will be described later.
[0032] <<Piston>> The piston 78 is accommodated inside the cylinder 88 so as to be able to reciprocate up and down. The piston 78 is urged downward in the up and down direction by the pressure in the pressure accumulator chamber 96. Specifically, the piston 78 reciprocates between top dead center and bottom dead center along the axial direction of the cylinder 88. A piston chamber 92 is formed by the piston 78 partitioning the interior of the cylinder 88. The volume of the piston chamber 92 increases and decreases as the piston 78 reciprocates. A seal member is provided on the outer peripheral surface of the piston 78. A driver blade 82 is connected to the underside of the piston 78.
[0033] <<Driver Blade>> The driver blade 82 is, for example, a metal plate-shaped member. The driver blade 82 extends downward from the underside of the piston 78 in the vertical direction. The piston 78 is movable in the vertical direction. Therefore, the driver blade 82 can move back and forth vertically inside the cylinder 88 together with the piston 78. The driver blade 82 is provided with a plurality of racks 83 (FIG. 3) spaced at predetermined intervals in the vertical direction. The driver blade 82 strikes downward the heads of the nails N sequentially supplied to the injection passage 46 (FIG. 1).
[0034] <First Drive Unit> The first drive unit 84 drives the impact unit 76. The first drive unit 84 has an impact force generation unit 86, a motor 102, a speed reduction mechanism unit 104, a drive shaft unit 106, a rotating unit 108, and a cam 116. The first drive unit 84 is operated by receiving electric power and is a component that enables the impact unit 76 to move upward in the vertical direction against the biasing force of the impact force generation unit 86 ( FIG. 1 ).
[0035] 1 , the impact force generating unit 86 urges the striking portion 76 in the second direction. The striking force generating unit 86 is, for example, configured with a cylinder 88, a piston chamber 92, a pressure accumulator vessel 94, and a pressure accumulator chamber 96. In other words, the impact force generating unit 86 urges the striking portion 76 downward by the pressure of the compressed air in the pressure accumulator chamber 96.
[0036] The cylinder 88 is provided inside the cylinder portion 14. A damper 89 is provided at the bottom of the cylinder 88. The pressure accumulator vessel 94 is provided at the top inside the cylinder portion 14. The pressure accumulator vessel 94 forms a pressure accumulator chamber 96. The pressure accumulator chamber 96 is in communication with the piston chamber 92. The piston chamber 92 and the pressure accumulator chamber 96 are filled with compressed air, which is an example of a high-pressure gas.
[0037] The damper 89 is a member made of rubber or urethane. When the piston 78 reaches the bottom dead center, the damper 89 comes into contact with the piston 78 to prevent the piston 78 from colliding with the cylinder 88.
[0038] <<Power Supply Motor>> As shown in Fig. 1, the motor 102 has an output shaft 102A and a rotor 102B. The output shaft 102A extends in the front-rear direction. The motor 102 is housed in the motor housing portion 16. The motor 102 operates using power supplied from a battery 144, which will be described later. The motor 102 is a brushless motor.
[0039] <<Reduction Mechanism>> The reduction mechanism 104 includes a planetary gear. The output shaft 102A is connected to a pinwheel 112 (FIG. 2) via the reduction mechanism 104, which will be described later.
[0040] <<Drive Shaft>> As shown in Figure 2, the drive shaft 106 has a central axis along the front-rear direction, and is rotatably supported by the housing 12 (Figure 1). A rotational force is transmitted to the drive shaft 106 from the reduction mechanism 104 (Figure 1). The rotational force transmitted to the drive shaft 106 is transmitted to the rotating part 108.
[0041] <<Rotating Unit>> The rotating unit 108 rotates by the driving force of the first driving unit 84. The rotating unit 108 is provided so as to be able to engage with the striking unit 76. As the rotating unit 108 rotates, it moves the striking unit 76 in the direction opposite to the second direction. The rotating unit 108 rotates around a rotation axis C (FIG. 1). The rotating unit 108 has a pinwheel 112 and a plurality of pinion pins 114 provided on the pinwheel 112. The plurality of pinion pins 114 can be engaged with and disengaged from the plurality of racks 83 (FIG. 3), respectively. When the plurality of pinion pins 114 are disengaged from all of the racks 83, the rotational force of the pinwheel 112 is not transmitted to the driver blade 82.
[0042] <<Cam>> The cam 116 converts the rotational movement of the first driving unit 84 into vertical linear movement of the switching unit 118, which will be described later.
[0043] <<<Position and Operation of Striking Section>>> In the following description, the position of the upper end of the driver blade 82 in the up-down direction is referred to as the position of the striking section 76. However, the position of the striking section 76 may be set to another position in the up-down direction of the driver blade 82. The striking section 76 can perform the following first, second, and third operations.
[0044] When the operator operates the operating unit 32 (FIG. 1), the striking unit 76 shown in FIG. 2 engages with the rotating unit 108, which rotates in the R direction (arrow R in FIG. 3), causing the striking unit 76 to move in the direction opposite to the second direction (upward) against the biasing force of the striking force generating unit 86. Specifically, the striking unit 76 moves (rises) from the first position P1 to the second position P2. This is referred to as the first operation of the striking unit 76.
[0045] When the engagement between the striking unit 76 and the rotating unit 108 is released as the rotating unit 108 rotates, the striking unit 76 receives the biasing force of the striking force generating unit 86 and moves (descends) from the second position P2 to a third position P3 in the second direction further than the first position P1, striking the nail N. This is the second operation of the striking unit 76. The third position P3 is located lower than the first position P1.
[0046] With the striking unit 76 re-engaged with the rotating unit 108, the rotating unit 108 rotates in the R direction, causing the striking unit 76 to move (rise) from the third position P3 to the first position P1 against the biasing force of the striking force generating unit 86. This is referred to as the third operation of the striking unit 76.
[0047] The first position P1 corresponds to a standby position (initial position) of the striking portion 76. The second position P2 corresponds to the top dead center of the striking portion 76. The third position P3 corresponds to the bottom dead center of the striking portion 76. When the striking portion 76 is located at the first position P1, the lower end of the striking portion 76 is located below the upper end of the nails N supplied by the feeder 66.
[0048] <Switching Unit> The switching unit 118 shown in Figure 3 is provided on the housing 12 (Figure 1). The switching unit 118 switches the position of a restricting member 142 (Figure 2), which will be described later, by abutting against the restricting member 142. The switching unit 118 has a switching member 122, a guide member 123, a first spring 126, and a second spring 128. The switching unit 118 receives a driving force from the first driving unit 84 (Figure 2) and switches the position of the restricting member 142 between the restricting position and the allowing position.
[0049] <Second Drive Unit> The second drive unit 132 shown in Fig. 2 drives the feeder 66. The second drive unit 132 has a solenoid 134. The solenoid 134 has a solenoid body 134A and a plunger 134B. The solenoid body 134A is attached to the guide unit 54. The plunger 134B extends from the solenoid body 134A to the other side in the K direction. When the second drive unit 132 receives electric power, the plunger 134B reciprocates in the K direction, thereby reciprocating the feeder 66 in the K direction.
[0050] <Solenoid Spring> The solenoid spring 136 is an example of an elastic body that biases the feeder 66 in the first direction. A plunger 134B is inserted into the solenoid spring 136. The solenoid spring 136 is inserted between the solenoid body 134A and the movable member 68, and biases the movable member 68 toward the other side in the K direction. The movable member 68 and the plunger 134B are fixed (connected). In other words, the solenoid spring 136 biases the feeder 66 toward the other side in the K direction.
[0051] When the power supply to the second drive unit 132 is turned off, the feeder 66 is urged toward the other side in the direction K by the urging force of the solenoid spring 136. In other words, the nails N are sent out into the ejection passage 46.
[0052] On the other hand, when the power supply to the second drive unit 132 is ON, the plunger 134B moves to one side in the K direction against the biasing force of the solenoid spring 136. In other words, the feeder 66 is moved to one side in the K direction.
[0053] 2, the restricting member 142 is provided on the guide portion 54. The restricting member 142 is capable of changing its position between a restricting position and an allowable position by rotating around a pin 65 provided on the guide portion 54. The restricting member 142 restricts movement of the movable member 68 to the other side in the K direction. In other words, the restricting member 142 is an example of a restricting portion that restricts movement of the feeder 66, which has moved in a first direction, in a direction opposite to the first direction. The restricting member 142 restricts movement of the feeder 66 to the other side in the K direction by coming into contact with the feeder 66.
[0054] 1 is detachably provided on the attachment portion 26. The battery 144 is an example of a power supply portion that supplies power to the first drive portion 84 and the second drive portion 132.
[0055] <Control Unit> The control unit 150 shown in Fig. 1 is, for example, a microcomputer including a processor, a memory, and a timer. The control unit 150 controls the operation of each part of the nail gun 10. Here, the control operation by the control unit 150 will be summarized. Note that for each component of the nail gun 10, reference will be made to Figs. 1 to 5, and individual figure numbers will be omitted.
[0056] <<Settings of the Control Unit>> The control unit 150 can control the effective value (VA, VB) of the voltage supplied to at least one of the first drive unit 84 and the second drive unit 132, depending on the available power WA ( FIG. 7 ) that can be supplied from the battery 144 to the first drive unit 84 and the second drive unit 132. The control unit 150 then changes the effective value VA of the voltage supplied to the first drive unit 84 and the effective value VB of the voltage supplied to the second drive unit 132, depending on the available power WA.
[0057] 7 , the control unit 150 sets the effective voltage value VA, the effective voltage value VB, and the target value Is of the current flowing through the second drive unit 132 according to the available power WA of the battery 144. As an example, the available power WA is set to available powers WA1, WA2, and WA3.
[0058] For the effective voltage value VA, VA1, VA2, and VA3 are set for the available power supplies WA1, WA2, and WA3. For the effective voltage value VB, VB1, VB2, and VB3 are set for the available power supplies WA1, WA2, and WA3. For the target current value Is, Is1, Is2, and Is3 are set for the available power supplies WA1, WA2, and WA3. Is1, Is2, and Is3 may be the same value.
[0059] The control unit 150 controls the supply of power from the battery 144 to the second drive unit 132, thereby moving (pulling) the feeder 66 in the direction opposite to the first direction. The control unit 150 controls the effective value VB of the voltage supplied to the second drive unit 132 so as to reduce the difference between the value of the current I flowing through the second drive unit 132 and the target current value Is. The control unit 150 also controls the effective value VA of the voltage supplied to the first drive unit 84 so as to reduce the difference between the value of the current I flowing through the second drive unit 132 and the target current value IS.
[0060] The control unit 150 sets a reference power WS for the available power WA. In this embodiment, an available power WA2 is set as an example of the reference power WS. When the available power WA is greater than the reference power WS (WA2), the control unit 150 increases the effective value VA of the voltage supplied to the first drive unit 84. When the available power WA is less than the reference power WS, the control unit 150 decreases the effective value VA of the voltage supplied to the first drive unit 84.
[0061] When the striking section 76 is performing at least one of the second and third operations described above, the control section 150 controls the supply of power from the battery 144 to the second driving section 132, thereby causing the second driving section 132 to drive the feeder 66.
[0062] <<Operational Control of Nail Gun by Control Unit>> When the control unit 150 receives both a signal generated by the operation of the push lever 48 and a signal generated by the operation of the trigger 34, it supplies a motor current to the motor 102 to operate the motor 102. This rotates the pinwheel 112, pushing up the driver blade 82 and moving the piston 78 from the bottom dead center to the top dead center. Thereafter, the piston 78 moves from the top dead center toward the bottom dead center, causing the driver blade 82 to descend.
[0063] That is, in the nail driver 10, the piston 78 reciprocates once between the bottom dead center and the top dead center under the control of the control unit 150. As this reciprocating motion occurs, the nail N is struck by the driver blade 82, causing the nail N to be driven out of the support portion 42. In this case, the driving operation of the nail N is performed once. The control unit 150 also controls the driving operation of the nail N to be performed continuously.
[0064] <Circuit Block Diagram> Figure 6 shows a circuit block diagram of the nail gun 10. Components already described are assigned the same reference numerals and will not be described again. The nail gun 10 has a main circuit unit 152. The battery 144 supplies power to the main circuit unit 152 via a connector 153 provided on the mounting portion 26.
[0065] The main circuit unit 152 includes the trigger switch 36, the first drive unit 84, the second drive unit 132, and the control unit 150, as well as an inverter circuit 154, a control signal output circuit 156, three magnetic sensors H, a rotational position detection circuit 158, and a rotation speed detection circuit 159. The main circuit unit 152 also includes a blade detector switch 161, a blade detector switch operation detection circuit 162, a solenoid control signal output circuit 163, a switching element S7, a voltage detection circuit 164, a first current detection circuit 165, and a second current detection circuit 166.
[0066] Furthermore, the main circuit section 152 has a power switch circuit 168 , a power supply voltage supply circuit 169 , a trigger switch operation detection circuit 171 , a push switch 172 , a push switch operation detection circuit 173 , a nail remaining amount switch 174 , and a nail remaining amount switch operation detection circuit 175 .
[0067] The inverter circuit 154 converts the power W supplied from the battery 144 into drive power and supplies it to the motor 102. The inverter circuit 154 includes, as an example, switching elements S1, S2, S3, S4, S5, and S6 connected in a three-phase bridge. The control signal output circuit 156 operates the inverter circuit 154 based on instructions from the control unit 150.
[0068] The three magnetic sensors H detect the rotational state of the rotor 102B. The rotational position detection circuit 158 detects the rotational position of the motor 102 based on the information on the rotational state of the rotor 102B obtained from the three magnetic sensors H. The rotational position information obtained by the rotational position detection circuit 158 is transmitted to the control unit 150. The rotation speed detection circuit 159 detects the rotation speed of the motor 102 based on the information obtained from the rotational position detection circuit 158. The rotation speed information obtained by the rotation speed detection circuit 159 is transmitted to the control unit 150.
[0069] The blade detector switch 161 is normally in the OFF state and turns ON when it comes into contact with the driver blade 82 (FIG. 2). The blade detector switch operation detection circuit 162 detects the vertical position and movement state (downward, upward) of the driver blade 82 based on the ON information and OFF information from the blade detector switch 161. The information detected by the blade detector switch operation detection circuit 162 is sent to the control unit 150.
[0070] The solenoid control signal output circuit 163 switches the switching element S7 based on an instruction signal received from the control unit 150, thereby operating the second drive unit 132. The voltage detection circuit 164 detects a voltage corresponding to the remaining power of the battery 144 when power is supplied to the first drive unit 84 via the inverter circuit 154. The first current detection circuit 165 detects the motor current (A) flowing through the motor 102. The second current detection circuit 166 detects the effective value (A) of the current flowing through the second drive unit 132 (solenoid 134).
[0071] The power switch circuit 168 is a switch that can be switched ON or OFF by an operator. When the power switch circuit 168 is in the ON state, it causes the power supply voltage supply circuit 169 to supply power supply voltage to the control unit 150, and when it is in the OFF state, it stops the supply of power supply voltage. The trigger switch operation detection circuit 171 detects whether the trigger switch 36 has been operated to the ON side, and transmits information about the ON or OFF state of the trigger switch 36 to the control unit 150.
[0072] The push switch 172 switches from OFF to ON when the push lever 48 (FIG. 1) comes into contact with the mating material G. It switches from ON to OFF when the push lever 48 is released from the mating material G. The push switch operation detection circuit 173 detects whether the push switch 172 is ON or OFF, and transmits the ON or OFF status of the push switch 172 to the control unit 150. The nail remaining amount switch 174 turns ON when the remaining amount of nails N in the magazine 52 (FIG. 1) falls below a predetermined value. The nail remaining amount switch operation detection circuit 175 transmits information to the control unit 150 as to whether the nail remaining amount switch 174 is ON or not.
[0073] [Operation of Nailer] The operation of the nailer 10 will be described. Note that the reference numerals of the components of the nailer 10 will be referred to in Figs. 1 to 6, and individual drawing numbers will be omitted.
[0074] <Motor Duty Adjustment Process> Each process shown in Fig. 8 is performed by the processor in the control unit 150 reading a processing program from memory, expanding it in a part of the memory, and executing it. Note that each process shown in Fig. 8 is an example of processing by the control unit 150.
[0075] In step S10, the control unit 150 causes the voltage detection circuit 164 to detect a voltage corresponding to the remaining power of the battery 144. Then, the process proceeds to step S12.
[0076] In step S12, the control unit 150 sets a target duty for driving the solenoid 134 based on the voltage of the battery 144 detected in step S10. For example, if the voltage of the battery 144 is higher than the reference voltage, the control unit 150 sets the target duty to a large value. If the voltage of the battery 144 is lower than the reference voltage, the control unit 150 sets the target duty to a small value. Then, the process proceeds to step S14.
[0077] In step S14, the control unit 150 turns on a timer for starting the energization of the solenoid 134. Then, the process proceeds to step S16.
[0078] In step S16, the control unit 150 sets a target duty of the motor 102. For example, if the target duty for driving the solenoid 134 is smaller than a reference value, the control unit 150 sets the target duty of the motor 102 to a larger value. If the target duty for driving the solenoid 134 is larger than the reference value, the control unit 150 sets the target duty of the motor 102 to a smaller value. Then, the process proceeds to step S18.
[0079] In step S18, the control unit 150 determines whether the current value I detected by the second current detection circuit 166 deviates from the target current value Is corresponding to the target duty of the solenoid 134. If it is determined that the current value I deviates from the target current value Is (S18: Yes), the control unit 150 proceeds to step S20. If it is determined that the current value I does not deviate (within the error range) (S18: No), the control unit 150 proceeds to step S22.
[0080] In step S20, the control unit 150 adjusts the duty value of the motor 102 to adjust the effective value of the current of the solenoid 134. Note that in step S20, the control unit 150 may adjust the effective value of the current of the solenoid 134 by adjusting the duty value of the solenoid 134. Then, the process proceeds to step S22.
[0081] In step S22, the control unit 150 determines whether the elapsed time measured by the timer since the energization of the solenoid 134 is 30 ms or more. If the elapsed time is 30 ms or more (S22: Yes), the control unit 150 proceeds to step S24. If the elapsed time is less than 30 ms (S22: No), the control unit 150 proceeds to step S18.
[0082] In step S24, the control unit 150 stops the power supply to the solenoid 134. Then, the process proceeds to step S26.
[0083] In step S26, the control unit 150 rotates the motor 102 at a duty of 100%. This causes the driver blade 82 to rise to the second position P2. Then, the process proceeds to step S28. After the power supply to the solenoid 134 is stopped, power distribution to the solenoid 134 is no longer necessary, and the duty of the motor 102 can be set to 100%.
[0084] In step S28, the control unit 150 determines whether the driver blade 82 has reached the first position P1. If the driver blade 82 has reached the first position P1 (S28: Yes), the process ends. If the driver blade 82 has not reached the first position P1 (S28: No), the process proceeds to step S26. Note that when the operation of the motor 102 (striking unit 76 (FIG. 1)) is completed, the process starts again from step S10. As a result, the nail driver 10 continuously supplies nails N to the support unit 42 and continuously strikes the nails N (continuous firing).
[0085] <Timing chart of solenoid and motor> Figure 9 shows graphs G1, G2, G3, G4, G5, and G6 for the nail driver 10 (Figure 1) of this embodiment as examples. In all cases, the horizontal axis represents time (point in time). Note that graphs GA, GB, GC, and GD shown in Figure 9 are graphs for comparative examples that do not have the control unit 150. Individual drawing numbers for each component of the nail driver 10 will be omitted.
[0086] Graph G1 shows the change over time in the current value I (A) flowing through the motor 102. Graph G2 shows the change over time in the duty (%) preset for passing the current value I through the motor 102. Graph G3 shows the change over time in the effective value (A) of the current flowing through the solenoid 134. Graph G4 shows the change over time in the duty (%) preset for passing the effective current value through the solenoid 134.
[0087] Graph G5 shows the change in the position (mm) of the solenoid 134 (plunger 134B, feeder 66) in the K direction when the solenoid 134 operates at the effective value of the current of graph G3. Regarding the position of the plunger 134B in the K direction, the position on one end side is defined as position K2 (mm). Furthermore, the position on the other end side of position K2 in the K direction where the movement of the plunger 134B is restricted by the restricting member 142 is defined as latch position K1 (mm). Furthermore, regarding the position of the plunger 134B in the K direction, the position on the other end side is defined as position 0 (mm).
[0088] Graph G6 shows the change in the vertical position (mm) of driver blade 82 when motor 102 operates with the current value of graph G1. As described above, the initial position of driver blade 82 before operation is defined as first position P1, the position at top dead center is defined as second position P2, and the position at bottom dead center is defined as third position P3.
[0089] 9, before time t1, the driver blade 82 is at a first position P1. The duty setting of the motor 102 is 0 (%), and the current flowing through the motor 102 is A0 (A).
[0090] On the other hand, the plunger 134B is at the latched position K1. The duty setting value of the solenoid 134 is 0 (%), and the effective value of the current flowing through the solenoid 134 is B0 (A).
[0091] During the period from time t1 to just before time t2, the motor 102 starts driving from a duty of 40%. As a result, the driver blade 82 starts rising from the first position P1. Meanwhile, the plunger 134B is in the latched position K1.
[0092] At time t2, the driver blade 82 is rising. Meanwhile, the plunger 134B is released from the restriction (latch) by the restriction member 142, and receives the biasing force of the solenoid spring 136, so that the plunger 134B starts to move toward the other side in the K direction. In other words, the feeder 66 starts to move toward the other side in the K direction.
[0093] During the period from time t2 to just before time t3, the driver blade 82 continues to rise. Meanwhile, the plunger 134B reaches the other end in the K direction, position 0 (mm), and stops. At this time, the nail N is being supplied to the support portion 42.
[0094] At time t3, the driver blade 82 reaches the second position P2 (top dead center) and stops. Meanwhile, the plunger 134B is at the other end in the K direction, ie, at a position 0 (mm).
[0095] From time t3 to just before time t4, the driver blade 82 receives an impact force from the impact force generating unit 86 while the motor 102 is operating at a duty of 100 (%). As a result, the driver blade 82 descends from the second position P2 to the third position P3 and ejects the nail N. Meanwhile, the plunger 134B is at the other end in the K direction, at position 0 (mm).
[0096] At time t4, the driver blade 82 is at the third position P3. Meanwhile, the second drive unit 132 starts driving the plunger 134B, causing the plunger 134B to start moving toward the position K2.
[0097] During the period from time t4 to just before time t5, the solenoid 134 is controlled so that the effective value of the current is B1 (A). For example, the duty of the solenoid 134 is set to D1 (%), but if the effective value of the current is less than B1, the duty is changed (controlled) to D2 (%) or D3 (%). Then, the plunger 134B reaches position K2.
[0098] On the other hand, during the period from time t4 to immediately before time t5, the duty of the motor 102 is set to M (%). Here, the duty of the motor 102 is set to M1 (%), which is less than M, or to M2 (%), which is more than M, in accordance with the change in the duty of the solenoid 134.
[0099] At time t5, the driver blade 82 is in the third position P3. Meanwhile, the plunger 134B is in the position K2. Here, at time t5, the duty of the solenoid 134 is reduced to 0 (%), and the effective value of the current of the solenoid 134 falls to B0 (A). In other words, the power required by the solenoid 134 decreases, and the power that can be supplied from the battery 144 to the motor 102 increases.
[0100] Between time t5 and time t6, the duty of the solenoid 134 is 0% and therefore only the biasing force of the solenoid spring 136 acts on the plunger 134B. The restricting member 142 restricts the movement of the plunger 134B. As a result, the plunger 134B is held at the latch position P1. Meanwhile, the duty of the motor 102 is set to 100%.
[0101] From time t6 to time t7, plunger 134B is held at latched position P1. Meanwhile, motor 102 is driven with a duty of 100% from the start. This causes a larger current value to be supplied to motor 102 than when driver blade 82 is driven simultaneously with solenoid 134, so that driver blade 82 rises from third position P3 to first position P1 in a short time.
[0102] In FIG. 9, all values except for the motor current value are constant from time t7 onwards, but in reality, the nail N is struck continuously, so each operation (each control) from time t1 to time t7 is repeated.
[0103] <Explanation of Comparative Example> Here, a comparative example of this embodiment will be described. In the comparative example, as shown in graph Gb, the effective value of the current used in the solenoid 134 is a value that exceeds B1. In the comparative example, the effective value of the current in the solenoid 134 exceeds B1 during the period from time t4 to time t5, and therefore the plunger 134B moves from position 0 (mm) to position K2 in a shorter time than in this embodiment (graph Gc).
[0104] However, in the comparative example, the effective value of the current of the solenoid 134 exceeds the required amount B1, and as shown in graph Ga, the effective value of the current available to the motor 102 is lower than in this embodiment. As a result, in the comparative example, a waiting time occurs until the effective value of the current required to drive the motor 102 is secured. Therefore, in the comparative example, the time at which the driver blade 82 reaches the first position P1 is t8 (graph Gd), which is later than time t7 in this embodiment. In other words, in the comparative example, it takes longer to fire nails N in rapid succession than in this embodiment. Furthermore, while the time required for the solenoid 134 to move to K2 is shorter, the time required to supply power to the solenoid 134 remains unchanged, resulting in excess power consumption even after the solenoid 134 reaches K2.
[0105] <Summary of Operation of the Present Embodiment> The operation of the nail driver 10 will be summarized below with reference to Fig. 1 to Fig. 9. Note that individual drawing numbers for the nail driver 10 will not be shown.
[0106] In the nail gun 10, the power WA that can be supplied from the battery 144 to the first drive unit 84 and the second drive unit 132 changes depending on the state of drive of the feeder 66 by the second drive unit 132. The control unit 150 then changes the effective value VA of the voltage of the first drive unit 84 depending on the changed available power WA. Here, for example, if the power consumed in driving the feeder 66 by the second drive unit 132 is small and there is a surplus in the available power WA, the control unit 150 can set a large effective value VA of the voltage that corresponds to the power supplied by the battery 144 to the first drive unit 84. This allows the drive speed of the first drive unit 84 to be increased, thereby improving the convenience of the work machine.
[0107] In the nail gun 10, the power consumption when the second drive unit 132 drives the feeder 66 to deliver the nails N is often less than the power consumption when the first drive unit 84 drives the striking unit 76. Here, for example, if the available power WA of the battery 144 is relatively low, the control unit 150 can ensure that a large amount of power can be supplied to the second drive unit 132 by minimizing the effective value VB of the voltage corresponding to the power supplied by the battery 144 to the second drive unit 132.
[0108] In the nail gun 10, the effective voltage value VB is controlled so that the difference between the current value I supplied to the second drive unit 132 and the target current value Is is small, thereby preventing excess power from being supplied to the second drive unit 132.
[0109] In the nail gun 10, not only the effective voltage value VB of the voltage of the second drive unit 132 but also the effective voltage value VA of the first drive unit 84 is changed so as to reduce the difference between the current value I supplied to the second drive unit 132 and the target current value Is. This makes it possible to further reduce (adjust) the difference between the current value I supplied to the second drive unit 132 and the target current value Is.
[0110] In the nail gun 10, when the available power WA contains surplus power greater than the reference power TS, the operating speed of the impact unit 76 can be increased by increasing the effective value VA of the voltage corresponding to the power supplied to the first drive unit 84. This allows the impact unit 76 to be used efficiently.
[0111] In the nail driver 10, a state in which the minimum necessary power is supplied to the first drive unit 84 is maintained, so that the available power WA of the battery 144 can be prevented from decreasing significantly in a short period of time.
[0112] In the nail gun 10, the power consumption during operation of the first drive unit 84 is smaller in the second and third operations than in the first operation. When at least one of the second and third operations is being performed, power is supplied from the battery 144 to the second drive unit 132. This makes it possible to prevent a shortage of power supplied from the battery 144 to the second drive unit 132.
[0113] In the nail gun 10, when power is supplied from the battery 144 to the second drive unit 132, the feeder 66 moves from the position where the striking unit 76 strikes the nails N toward the magazine 52. Here, when the feeder 66 moves toward the magazine 52, the nails N are not fed to the striking position. In other words, when the feeder 66 moves toward the magazine 52, it is not necessary to synchronize the timing of the positioning of the nails N. This increases the degree of freedom in setting the movement timing of the feeder 66. This allows the operation timing of the first drive unit 84 and the second drive unit 132 to be shifted, thereby reducing the total power consumption of the first drive unit 84 and the second drive unit 132 at a specific time.
[0114] In the nail gun 10, the solenoid spring 136 biases the feeder 66 toward the other side in the K direction, so there is no need to supply power to the second drive unit 132 when moving the nail N to the striking position of the support unit 42. This reduces power consumption compared to a configuration in which the second drive unit 132 reciprocates the feeder 66 in the K direction.
[0115] In the nail driver 10, the restricting member 142 restricts the movement of the feeder 66 located on one side in the K direction to the other side, thereby making it less likely that a misalignment will occur between a nail N that has already moved to the striking position and another nail N that will be moved by the feeder 66. This makes it possible to prevent misalignment of multiple nails N in the K direction. The restricting member 142 may be configured to release the restriction at the timing when the nail N is moved to the support part 42.
[0116] Modifications of the Present Embodiment Modifications of the present embodiment will be described below. In the following description, the same components as those in the nail driver 10 of the above embodiment will be given the same reference numerals, and the description thereof will be omitted.
[0117] 10 shows the duty settings, effective current values, and operating positions of the motor and solenoid in the modified nail driver 10. In the modified nail driver 10, the standby position of the striking unit 76 is the first position P1'. When the striking unit 76 is in the first position P1', the lower end of the striking unit 76 is located above the upper end of the nails N supplied by the feeder 66.
[0118] The driver blade 82 begins to rise from the first position P1' at time t1', then moves via the second position P2 to the third position P3, striking the fastener. At time t2', after the driver blade 82 strikes the fastener and starts moving from the third position P3 but before reaching the first position P1', the plunger 134B is released from the restriction (latch) by the restriction member 142, and receives the biasing force of the solenoid spring 136 and begins moving to the other side in the K direction. Thereafter, power supply to the solenoid 134 is started at time t3', and the plunger 134B begins to move toward position K2. At time t4', power supply to the solenoid 134 is stopped, and the plunger 134B is held at the latched position P1 at time t5'. The driver blade 82h reaches the first position P1' and stops at time t6'. During the period from time t3' to immediately before time t4', the duty of the motor 102 is set to M(%), which is less than 100(%), in order to supply power to the solenoid 134.
[0119] In the comparative example to this modification, as shown in graph Gb', the effective value of the current used by the solenoid 134 exceeds B1. In this comparative example to this modification, the effective value of the current used by the solenoid 134 also exceeds B1 from time t3' to time t4', so the plunger 134B moves from position 0 (mm) to position K2 in a shorter time than in this embodiment (graph Gc'). Furthermore, because the effective value of the current used by the solenoid 134 exceeds the required amount B1, the effective value of the current available to the motor 102 is lower than in this modification, as shown in graph Ga'. Therefore, the driver blade 82 reaches the first position P1' at time t7' (graph Gd'), which is later than the time t6' in this modification. In contrast, in this modification, the power supplied to the first drive unit 84 is changed to minimize the power supplied by the solenoid 134, thereby shortening the time it takes for the driver blade 82h to reach the first position P1' and improving the usability of the work machine.
[0120] This embodiment is not limited to the above-described embodiment and modified examples, and various modifications are possible without departing from the spirit and scope of the present invention. For example, in the nail gun 10, the control unit 150 may change only the effective voltage VB of the second drive unit 132 in accordance with the available power WA. When controlling the effective voltage VB of the second drive unit 132, the control unit 150 may not control the second drive unit 132 to reduce the difference between the current I flowing through the second drive unit 132 and the target current Is. When controlling the effective voltage VA of the first drive unit 84, the control unit 150 may not control the second drive unit 132 to reduce the difference between the current I flowing through the second drive unit 132 and the target current Is.
[0121] When the available power WA is greater than the reference power WS, the control unit 150 does not need to increase the effective value VA of the voltage of the first drive unit 84. When the available power WA is less than the reference power WS, the control unit 150 does not need to decrease the effective value VB of the voltage of the first drive unit 84.
[0122] The control unit 150 may not cause the second drive unit 132 to drive the feeder 66 while the striking unit 76 is performing at least one of the second operation and the third operation.
[0123] The nail gun 10 may be configured such that, when the control unit 150 causes the battery 144 to supply power to the second drive unit 132, the feeder 66 moves from one side to the other side in the K direction.
[0124] The restricting member 142 is not limited to a rotating member, and may be a member that switches between a restricting state and a non-restricting state by sliding in a direction intersecting the K direction. Also, the feeder 66 may be a member that moves between one side and the other side in the K direction only by the operation of the solenoid 134, without latching using the restricting member 142.
[0125] The control unit 150 may control the effective value of the voltage of at least one of the first drive unit 84 and the second drive unit 132 depending on the available power WA that can be supplied from the battery 144 to the first drive unit 84 and the second drive unit 132.
[0126] A solenoid may be used as the first drive unit 84, or a motor may be used as the second drive unit 132, and other electrically driven actuators may also be applied to the first drive unit 84 and the second drive unit 132. The impact force generating unit 86 may be configured to generate an impact force by combustion of combustible gas, or to generate an impact force by the elastic force of a mechanical spring.
[0127] 10...nail gun, 12...housing, 14...cylinder portion, 16...motor accommodating portion, 18...handle portion, 24...extension portion, 26...mounting portion, 32...operating portion, 34...trigger, 36...trigger switch, 42...support portion, 46...ejection passage, 47...rotating shaft, 48...push lever, 52...magazine, 53...drum portion, 54...guide portion, 56...lid portion, 58...supply passage, 60...supply portion, 62...claw member, 62A...base portion, 62B...plate portion, 62C...claw portion, 63...rotating shaft, 64...spring, 65...pin, 66...feeder, 68...movable member, 68A...fixed portion, 68B...contact portion, 68C...shaft portion, 72...feed member, 72A...first claw portion, 72B...second claw portion, 75...spring, 76...impact portion, 78...piston, 82...driver blade, 83...rack, 84...first drive portion, 86...impact force generating portion, 88...cylinder, 89...damper, 92...piston chamber, 94...pressure accumulator vessel, 96...pressure accumulator chamber, 102...motor, 102A...output shaft, 102B...rotor, 104...reduction mechanism portion, 106...drive shaft portion, 108...rotating portion, 112...pinwheel, 114...pinion pin, 116...cam, 118...switching portion, 122...switching member, 123...guide member, 126...first spring , 128...second spring, 132...second drive unit, 134...solenoid, 134A...solenoid body, 134B...plunger, 136...solenoid spring, 142...regulating member, 144...battery, 150...control unit, 152...main circuit unit, 153...connector, 154...inverter circuit, 156...control signal output circuit, 158...rotational position detection circuit, 159...rotation speed detection circuit, 161...blade detector switch, 162...blade detector switch operation detection circuit, 163...solenoid control signal output circuit, 164...voltage detection circuit, 165...first current detection circuit path, 166...second current detection circuit, 168...power switch circuit, 169...power supply voltage supply circuit, 171...trigger switch operation detection circuit, 172...push switch, 173...push switch operation detection circuit, 174...nail remaining amount switch, 175...nail remaining amount switch operation detection circuit, C...rotation axis, G...mating material, Is...target current value, Is1...target current value, Is2...target current value, Is3...target current value, K...direction, M...connecting portion, N...nail, P1...first position, P2...second position, P3...third position, R...direction, VA...effective value of voltage, VA1...effective value of voltage, VA2...effective value of voltage,VA3...effective value of voltage, VB...effective value of voltage, VB1...effective value of voltage, VB2...effective value of voltage, VB3...effective value of voltage, WA...supplyable power, WA1...supplyable power, WA2...supplyable power, WA3...supplyable power, WS...reference power,
Claims
1. A feeder that delivers fasteners from the magazine, A striking section for striking the fastener that has been fed out by the feeder, A first drive unit that drives the striking unit, A second drive unit that drives the feeder, A battery that supplies power to the first drive unit and the second drive unit, The system includes a control unit that controls the effective value of the voltage supplied to at least one of the first drive unit and the second drive unit according to the available power that can be supplied to the first drive unit and the second drive unit from the battery, The control unit supplies the surplus power from the available power that is required to drive the second drive unit to the first drive unit. The control unit has a reference power set for the available power supply. The control unit increases the effective value of the voltage supplied to the first drive unit when the available power is greater than the reference power.
2. The work machine according to claim 1, wherein the control unit increases the effective value of the voltage supplied to the second drive unit when the supplyable power is a first value, compared to when the supplyable power is a second value smaller than the first value.
3. The control unit has a target value set for the current flowing through the second drive unit according to the available power supply. The work machine according to claim 2, wherein the control unit controls the effective value of the voltage supplied to the second drive unit so that the difference between the value of the current flowing through the second drive unit and the target value of the current becomes small.
4. The work machine according to claim 3, wherein the control unit controls the effective value of the voltage supplied to the first drive unit so that the difference between the value of the current flowing through the second drive unit and the target value of the current becomes small.
5. The work machine according to claim 1, wherein the control unit reduces the effective value of the voltage supplied to the first drive unit when the available power is less than the reference power.
6. When the direction in which the feeder delivers the fastener from the magazine is defined as the first direction, and the direction in which the striking part strikes the fastener, which intersects the first direction, is defined as the second direction, the first direction and the second direction intersect, The first drive unit is, A striking force generating unit that biases the striking portion in the second direction, It has a rotating part that is engaged with the striking part and moves the striking part in a direction opposite to the second direction as it rotates, The striking part is, When the operating part is operated by an operator, the rotating part rotates while engaged with the rotating part, causing a first operation in which the device moves from the first position to the second position in the direction opposite to the second direction, against the biasing force of the striking force generating part. When the engagement with the rotating part is released as the rotating part rotates, the biasing force of the striking force generating part causes it to move from the second position to a third position in the second direction relative to the first position, and strike the fastener in a second operation. With the rotating part re-engaged, the rotating part rotates, enabling a third operation in which it moves from the third position to the first position against the biasing force of the striking force generating part. The work machine according to claim 1, wherein when the striking unit is performing at least one of the second operation and the third operation, the control unit supplies power from the battery to the second drive unit and drives the feeder by the second drive unit.
7. The control unit supplies power from the battery to the second drive unit, thereby moving the feeder in the direction opposite to the first direction. The work machine according to claim 6, wherein the feeder moves the fastener from the magazine to the striking position of the fastener.
8. An elastic body that biases the feeder in the first direction, The work machine according to claim 7, further comprising a restricting unit for restricting the movement of the feeder, which has moved in the first direction, in the direction opposite to the first direction.