Work equipment

Abstract

To provide a work machine which improves workability.SOLUTION: A work machine 1 includes: a motor 3; a tip tool mounting section which is driven by driving force of the motor 3 and can mount a tip tool; a Hall sensor 19 which can detect a type of the tip tool mounted in the tip tool mounting section; and an arithmetic section 42 which can switch control of the motor 3. The arithmetic section 42 is configured so that a rotation direction of the motor 3 can be switched on the basis of the type of the tip tool detected by the Hall sensor 19. The arithmetic section 42 can stop the motor 3 when current flowing in the motor 3 exceeds a threshold a prescribed number of times and can change at least one of the threshold and the prescribed number of times on the basis of the type of the tip tool.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a work machine such as an impact wrench. [Background technology]

[0002] The following Patent Document 1 discloses a work machine in which a set value (motor rotation speed) can be changed according to the type of tool bit identified by a tool bit identifying section. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-233793 Summary of the Invention [Problem to be solved by the invention]

[0004] Depending on the type of tool attached, it may be necessary to change the direction of rotation of the drive unit, such as the motor. For example, if a drive wrench is attached as the tool attached to an impact wrench, the motor's direction of rotation must be reversed for tightening work. If the appropriate direction of rotation cannot be selected depending on the type of tool attached, workability will be reduced.

[0005] An object of the present invention is to provide a work machine with improved workability. [Means for solving the problem]

[0006] One aspect of the present invention is a work machine. A drive unit; a tool attachment unit that is driven by the driving force of the drive unit and that can attach a tool; a tool bit detection unit capable of detecting the type of tool bit attached to the tool bit attachment unit; a control unit capable of switching control of the drive unit, The control unit is configured to be able to switch the rotation direction of the drive unit based on the type of the tool bit detected by the tool bit detection unit.

[0007] Another aspect of the present invention is a work machine. A drive unit; a tool attachment unit that is driven by the driving force of the drive unit and that can attach a tool; a tool tip selection unit that can select the type of tool tip to be attached to the tool tip attachment unit; a control unit capable of switching control of the drive unit, The control unit is configured to be able to switch the rotation direction of the drive unit based on the type of tool bit selected by the tool bit selection unit.

[0008] Yet another aspect of the present invention is a work machine. A drive unit; a tool attachment unit that is driven by the driving force of the drive unit and that can attach a tool; a control unit capable of switching control of the drive unit, The control unit is configured to be able to switch the rotation direction of the drive unit based on the type of the tool bit input from an external device.

[0009] The present invention may be expressed as an "electric working machine," "electric tool," "electrical equipment," etc., and such expressions are also valid as aspects of the present invention. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a work machine with improved workability. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a side cross-sectional view of a work machine 1 according to a first embodiment of the present invention, in a state where no tool bit is attached. [Figure 2] FIG. 2 is a side cross-sectional view of the work machine 1 with a foundation drive wrench 16 attached as a tip tool. [Figure 3] FIG. 1 is a side cross-sectional view of the work machine 1 with a panel drive wrench 17 attached as a tip tool. [Figure 4] FIG. 2 is a partial cross-sectional side view of the work machine 1 with a universal socket 18 attached as a tip tool. [Figure 5] 2 is a partial cross-sectional side view showing a configuration relating to tool tip detection of the work machine 1. FIG. [Figure 6] FIG. 2 is a circuit block diagram of the work machine 1. [Figure 7] 5 is a diagram showing the transition of drive modes of the work machine 1 according to the detection result of the tool tip. [Figure 8] 5 is a flowchart showing a first control example of a work machine 1 equipped with a foundation drive wrench 16. [Figure 9] 10 is a flowchart showing a second control example of the work machine 1 equipped with the foundation drive wrench 16. [Figure 10] 10 is a flowchart showing a third control example of the work machine 1 equipped with the foundation drive wrench 16. [Figure 11] 4 is a graph showing an example of a current waveform of a motor 3 when a work machine 1 equipped with a foundation drive wrench 16 is in operation. [Figure 12] 4 is a graph showing an example of a rotational speed waveform of a motor 3 when a work machine 1 equipped with a foundation drive wrench 16 is in operation. [Figure 13] 1A is a schematic diagram of a work machine system according to a second embodiment of the present invention, the work machine system including a work machine 1A and an external device 80A; FIG. 1B is an external view of an operation panel 20A of the work machine 1A; and FIG. 1C is a diagram showing an example of a screen display of a setting application for the external device 80A. [Figure 14] 4 is a diagram showing the transition of drive modes of the work machine 1A in response to the operation of the mode changeover switch 21 on the operation panel 20A. FIG. [Figure 15] 10 is an explanatory diagram of a change in the stop condition of the motor 3 in accordance with a power selection by the setting application of the external device 80A in the foundation drive wrench mode. FIG. [Figure 16] 10 is an explanatory diagram of a change in the stop condition of the motor 3 in accordance with a power selection by the setting application of the external device 80A in the panel drive wrench mode. FIG. [Figure 17] 10 is an explanatory diagram of a change in the stop condition of the motor 3 in accordance with a power selection by the setting application of the external device 80A in the universal socket mode. FIG. [Figure 18] 1A is a schematic diagram of a work machine system according to a third embodiment of the present invention, the work machine system including a work machine 1B and an external device 80B; FIG. 1B is an external view of an operation panel 20B of the work machine 1B; and FIG. 1C is a diagram showing an example of a screen display of a setting application for the external device 80B. [Figure 19] 10 is a diagram showing the transition of drive modes of the work machine 1B in accordance with a mode selection by a setting application of the external device 80B. [Figure 20] FIG. 10 is an explanatory diagram of a change in the stop condition of the motor 3 in response to the operation of the power selector switch 25 on the operation panel 20B in the foundation drive wrench mode. [Figure 21] 10 is an explanatory diagram of a change in the stop condition of the motor 3 in response to the operation of the power selector switch 25 in the panel drive wrench mode. FIG. [Figure 22] 10 is an explanatory diagram of a change in the stop condition of the motor 3 in response to the operation of the power selector switch 25 in the universal socket mode. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] In the following, identical or equivalent components, members, etc. shown in each drawing are denoted by the same reference numerals, and redundant explanations will be omitted where appropriate. The embodiments are illustrative and do not limit the invention. All features and combinations thereof described in the embodiments are not necessarily essential to the invention.

[0013] (Embodiment 1) 1 to 12 relate to a work machine 1 according to a first embodiment of the present invention. FIG. 1 defines the front-rear and up-down directions of the work machine 1, which are perpendicular to each other. The front-rear direction is a direction parallel to a motor shaft 3a of the work machine 1. The work machine 1 is an electric power tool, and more specifically, an impact wrench. The work machine 1 has a housing 2.

[0014] The housing 2 includes a body 2a, a handle 2b, and a battery pack mounting portion 2c. The body 2a is a cylindrical portion whose central axis is approximately parallel to the front-to-rear direction. The housing 2 includes a hammer case 11 made of, for example, metal, connected to the front of the body 2a.

[0015] The handle 2b has an upper end connected to a middle portion of the body 2a in the front-rear direction and extends downward from the middle portion. The work machine 1 has a trigger switch 6 and a forward / reverse switching lever 13 (forward / reverse switching button) at the upper end of the handle 2b.

[0016] The trigger switch 6 is a drive operation unit that allows the user to switch between driving and stopping the motor 3 (driving state of the motor 3). The trigger switch 6 is a stepless speed change switch. The forward / reverse switching lever 13 is a rotation direction switching unit that allows the user to switch between forward and reverse rotation of the motor 3, i.e., forward (right rotation) and reverse (left rotation) of the anvil 10 (described later).

[0017] The battery pack attachment section 2c is provided at the lower end of the handle section 2b, and allows the battery pack 7 to be detachably attached. The work machine 1 operates using power from the battery pack 7. As an example, the battery pack 7 has an output voltage of 40V or more when fully charged. The work machine 1 has an operation panel 20 (switch panel) on the front upper surface of the battery pack attachment section 2c. The work machine 1 has a control board 30 inside the battery pack attachment section 2c.

[0018] The work machine 1 has a motor 3 as a drive unit, a reduction mechanism 4, a spindle 5, a hammer 8, a spring 9, and an anvil 10 as a tool attachment unit, all housed within a body 2a and a hammer case 11. The reduction mechanism 4, spindle 5, hammer 8, and spring 9 constitute a rotary impact mechanism that converts the drive force (rotational force) of the motor 3 into rotary impact force and applies it to the anvil 10.

[0019] The motor 3 is an inner rotor type brushless motor. The reduction mechanism 4 reduces the rotation speed of the motor 3 and transmits it to the spindle 5. The spindle 5 rotates the hammer 8. A spring 9 biases the hammer 8 forward. The hammer 8 rotates or rotary strikes the anvil 10. In other words, the anvil 10 is driven by the driving force of the motor 3. The anvil 10 is rotatably supported by a hammer case 11.

[0020] The work machine 1 has a sensor / inverter board 15 at the rear of the body 2a. The sensor / inverter board 15 is equipped with a Hall IC 43 and an inverter circuit 45 shown in Fig. 3. The sensor / inverter board 15 is supported at the rear of the main body of the motor 3 (the part of the motor 3 excluding the motor shaft 3a) in a position approximately perpendicular to the motor shaft 3a.

[0021] In the work machine 1, various tool bits can be attached to the tip of the anvil 10 depending on the work being performed. Figure 2 shows the state where a foundation drive wrench 16 is attached to the tip of the anvil 10. Figure 3 shows the state where a panel drive wrench 17 is attached to the tip of the anvil 10. Figure 4 shows the state where a universal socket 18 is attached to the tip of the anvil 10.

[0022] The foundation drive wrench 16, the panel drive wrench 17, and the universal socket 18 are all tip tools used when the housing 2 cannot be inserted in the desired position due to constraints such as a small working space.

[0023] The foundation drive wrench 16 is used to tighten anchor bolts for residential foundations. The panel drive wrench 17 is used to fasten panels to steel frames and other frameworks during residential construction. The universal socket 18 is used to fasten pillars, beams, and other components to each other during residential construction.

[0024] The mounting bracket 14 shown in Figures 2 and 3 is an attachment required to mount the foundation drive wrench 16 or panel drive wrench 17, and is fixed to the housing 2 so as to span between the front end of the body 2a and the lower end of the handle 2b.

[0025] The foundation drive wrench 16 is configured to transmit the rotation of the anvil 10 upward via four gears 16a connected in series. The front gear 16a is directly connected to the tip of the anvil 10. The hexagonal socket provided in the last gear 16a is the output shaft 16b. A bolt can be fitted into the output shaft 16b to perform tightening work. The rotation direction of the output shaft 16b is opposite to the rotation direction of the anvil 10. In other words, when the anvil 10 rotates forward, the output shaft 16b rotates reversely, and when the anvil 10 rotates reversely, the output shaft 16b rotates forward. The foundation drive wrench 16 has a magnet 16c to identify itself to the work machine 1.

[0026] The panel drive wrench 17 shares a basic structure with the foundation drive wrench 16. The panel drive wrench 17 is configured to transmit the rotation of the anvil 10 upward via four gears 17a connected in series. The front gear 17a is directly connected to the tip of the anvil 10. The hexagonal socket on the rear gear 17a is the output shaft 17b. A bolt can be fitted onto the output shaft 17b to perform tightening work. The width across flats of the output shaft 17b is smaller than the width across flats of the output shaft 16b. The rotation direction of the output shaft 17b is opposite to the rotation direction of the anvil 10. In other words, when the anvil 10 rotates forward, the output shaft 17b rotates reversely, and when the anvil 10 rotates reversely, the output shaft 17b rotates forward. The panel drive wrench 17 has a magnet 17c to identify itself to the work machine 1.

[0027] The universal socket 18 includes a shaft 18a that rotates coaxially with the anvil 10, and a swiveling output shaft 18b that is connected to the tip of the shaft 18. A bolt can be fitted onto the output shaft 18b to perform tightening work. The rotation direction of the output shaft 18b is the same as the rotation direction of the anvil 10. In other words, when the anvil 10 rotates forward, the output shaft 18b rotates forward, and when the anvil 10 rotates reverse, the output shaft 18b rotates reverse.

[0028] As shown in Figure 5, the work machine 1 has a tool bit detection board 12 and a Hall sensor 19. The tool bit detection board 12 is located below the anvil 10 and is held in the housing 2 in a position facing forward. The Hall sensor 19 is provided on the front surface of the tool bit detection board 12. The Hall sensor 19 is a tool bit detection unit (tool bit detection sensor) that can detect the type of tool bit attached to the anvil 10.

[0029] The magnet 16c of the foundation drive wrench 16 attached to the tip of the anvil 10 faces the Hall sensor 19. Also, the magnet 17c of the panel drive wrench 17 attached to the tip of the anvil 10 faces the Hall sensor 19. The rear surface of the magnet 16c is the north pole surface, and the rear surface of the magnet 17c is the south pole surface. The universal socket 18 does not have a magnet facing the Hall sensor 19.

[0030] Therefore, when the Hall sensor 19 detects a north pole, i.e., when it detects a magnetic flux pointing backward, the tool attached to the anvil 10 can be determined to be a foundation drive wrench 16. When the Hall sensor 19 detects a south pole, i.e., when it detects a magnetic flux pointing forward, the tool attached to the anvil 10 can be determined to be a panel drive wrench 17. When the Hall sensor 19 does not detect a magnetic flux, the tool attached to the anvil 10 can be determined to be a universal socket 18.

[0031] 6 is a circuit block diagram of the work machine 1. A capacitor C is provided for noise prevention and is connected between the output terminals of the battery pack 7. A resistor R is provided for current or load detection and is connected to the path of the current (hereinafter referred to as "motor current") flowing through the motor 3. A Hall IC 43 (magnetic sensor) is a position sensor for detecting the rotational position of the motor 3.

[0032] The inverter circuit 45 converts the DC power output from the battery pack 7 into drive power for the motor 3 and supplies it to the motor 3. The inverter circuit 45 includes switching elements Q1 to Q6 connected in a three-phase bridge configuration.

[0033] The work machine 1 has a control board 30 which includes a current detection circuit 31, a switch operation detection circuit 33, a rotation direction setting circuit 34, a tool tip detection circuit 35, an operation panel circuit 36, a control signal output circuit 37, a rotation position detection circuit 38, a rotation speed detection circuit 39, and a calculation unit 42.

[0034] The current detection circuit 31 detects the motor current from the voltage across the resistor R and sends it to the calculation unit 42. The calculation unit 42 can detect the load on the motor 3 from the motor current. The switch operation detection circuit 33 detects the on / off status and operation amount (pulling amount) of the trigger switch 6 and sends it to the calculation unit 42. The rotation direction setting circuit 34 detects the rotation direction indicated by the forward / reverse switching lever 13 and sends it to the calculation unit 42.

[0035] The tip tool detection circuit 35 detects the tip tool attached to the tip of the anvil 10 based on the output signal of the Hall sensor 19 and sends the signal to the calculation unit 42. The operation panel circuit 36 ​​detects operations on the operation panel 20 and sends the signal to the calculation unit 42. In addition, the operation panel circuit 36 ​​applies a display control signal to a display unit such as an LED provided on the operation panel 20 under the control of the calculation unit 42.

[0036] The control signal output circuit 37 applies a signal, for example a PWM (Pulse Width Modulation) signal, to each control terminal (each gate) of the switching elements Q1 to Q6 under the control of the calculation unit 42. The rotational position detection circuit 38 detects the rotational position of the motor 3 (hereinafter referred to as the "motor rotational position") from the output signal of the Hall IC 43, and transmits it to the calculation unit 42. The rotation speed detection circuit 39 detects the rotation speed of the motor 3 (hereinafter referred to as the "motor rotation speed") from the output signal of the rotational position detection circuit 38, and transmits it to the calculation unit 42.

[0037] The calculation unit 42 constitutes a control unit that controls the overall operation of the work machine 1, such as driving the motor 3 and displaying information on the operation panel 20. The control unit may include not only the calculation unit 42, but also the entire configuration within the dashed line indicating the control board 30 in FIG. 6. The control unit may also include a Hall IC 43 and an inverter circuit 45.

[0038] The calculation unit 42 controls the driving of the motor 3 according to the operation of the trigger switch 6, the rotation direction (hereinafter referred to as the "instructed rotation direction") indicated (selected) by the forward / reverse switching lever 13, and the type of tool bit detected by the Hall sensor 19. The calculation unit 42 controls the driving of the motor 3 by receiving feedback of the motor current, motor rotation position, and motor rotation speed.

[0039] The calculation unit 42 sets the condition for stopping the motor 3 (hereinafter referred to as the "motor stop condition") as being that the peak value of the motor current equals or exceeds the threshold value a predetermined number of times. When the motor stop condition is met, the calculation unit 42 stops the motor 3 even if the trigger switch 6 is in the on state, i.e., even if the trigger switch 6 is operated to drive the motor. The motor stop condition is a condition for determining whether a specified torque (target torque) corresponding to the drive mode described below has been reached (a condition for completing tightening at the specified torque), and is set for each drive mode.

[0040] FIG. 7 is a diagram showing the transition of drive modes of the work machine 1 (calculation unit 42) according to the type of tool bit detected by the Hall sensor 19. The following explanation is based on the assumption that the rotation command direction is forward. In FIG. 7, the "tool output shaft" corresponds to the anvil 10. The same applies to FIGS. 14 to 17 and 19 to 22.

[0041] The calculation unit 42 switches the drive mode of the motor 3 among a foundation drive wrench mode, a panel drive wrench mode, and a universal socket mode according to the type of tool bit detected by the Hall sensor 19.

[0042] The foundation drive wrench mode is a mode when a foundation drive wrench 16 is attached to the anvil 10. In the foundation drive wrench mode, the calculation unit 42 sets the rotation direction of the motor 3 (hereinafter "motor rotation direction") to reverse, i.e., sets the rotation direction of the anvil 10 (hereinafter "anvil rotation direction") to reverse. In other words, in the foundation drive wrench mode, the calculation unit 42 sets the motor rotation direction and the anvil rotation direction to the opposite direction from the rotation instruction direction. In the foundation drive wrench mode, the calculation unit 42 sets the threshold value of the motor stop condition to 24A and the predetermined number of times to 2.

[0043] The panel drive wrench mode is a mode when a panel drive wrench 17 is attached to the anvil 10. In the panel drive wrench mode, the calculation unit 42 sets the motor rotation direction and the anvil rotation direction in the same way as in the foundation drive wrench mode. In the panel drive wrench mode, the calculation unit 42 sets the threshold for the motor stop condition to 25A and the predetermined number of times to 2.

[0044] The universal socket mode is a mode when a universal socket 18 is attached to the anvil 10. In the universal socket mode, the calculation unit 42 sets the motor rotation direction and the anvil rotation direction to forward rotation. That is, in the universal socket mode, the calculation unit 42 sets the motor rotation direction and the anvil rotation direction to the same direction as the rotation instruction direction. In the universal socket mode, the calculation unit 42 sets the threshold for the motor stop condition to 33A and the predetermined number of times to 2.

[0045] 7, the predetermined number of times for the motor stop condition is the same for each drive mode (twice), but the predetermined number of times may be different for each mode. If the predetermined number of times is different for each mode, the threshold value for the motor stop condition may be the same for each drive mode.

[0046] The calculation unit 42 transitions to the foundation drive wrench mode when the Hall sensor 19 detects the north pole. The calculation unit 42 transitions to the panel drive wrench mode when the Hall sensor 19 detects the south pole. The calculation unit 42 transitions to the universal socket mode when the Hall sensor 19 does not detect magnetic flux.

[0047] That is, the calculation unit 42 is configured to be able to switch the motor rotation direction and the anvil rotation direction based on the type of tool bit detected by the Hall sensor 19, regardless of the rotation command direction. The calculation unit 42 is also configured to be able to switch the threshold value and the predetermined number of times based on the type of tool bit detected by the Hall sensor 19. In this way, the calculation unit 42 can switch the control of the motor 3 based on the type of tool bit detected by the Hall sensor 19.

[0048] 8 is a flowchart showing a first control example in the foundation drive wrench mode. When the trigger switch 6 is turned on (S1), the calculation unit 42 checks whether the output voltage of the battery pack 7 (hereinafter referred to as "battery voltage") is equal to or greater than a predetermined value (38V) (S2). The battery voltage checked here is the battery voltage when the motor 3 is not being driven. The predetermined value (38V) is a value higher than the threshold for over-discharge protection of the battery pack 7. If the battery voltage is equal to or greater than the predetermined value (38V) (Yes in S2), the calculation unit 42 drives the motor 3 in the reverse direction (S3).

[0049] The calculation unit 42 continues to drive the motor 3 in the reverse direction until it counts two peak values ​​of the motor current equal to or greater than 24 A (No in S4). If the calculation unit 42 counts two peak values ​​of the motor current equal to or greater than 24 A (Yes in S4), that is, if the motor stop condition is met, it stops the motor 3 (S5).

[0050] If the battery voltage is not equal to or greater than the predetermined value (38V) in S2 (No in S2), the calculation unit 42 determines that the motor 3 cannot be driven (S6) and does not drive the motor 3. In this case, the calculation unit 42 may notify the user by displaying a message on the operation panel 20. The battery voltage being less than the predetermined value (38V) is an example of a predetermined condition related to a voltage drop in the battery pack 7.

[0051] In the first control example shown in FIG. 8, by not driving the motor 3 when the battery voltage is below a predetermined value (38 V), it is possible to prevent the tightening torque from becoming insufficient relative to the specified value due to a drop in the voltage of the battery pack 7.

[0052] The flowchart in FIG. 8 can be applied to panel drive wrench mode by changing the content of S4, i.e., the motor stop condition, and can also be applied to universal socket mode by setting the motor rotation direction in S3 to forward rotation.

[0053] 9 is a flowchart showing a second control example of the foundation drive wrench mode. The control flow of S1 to S5 in FIG. 9 is the same as the control flow of S1 to S5 in FIG.

[0054] If the battery voltage is not equal to or greater than the first predetermined value (38V) in S2 (No in S2), the calculation unit 42 checks whether the battery voltage is equal to or greater than a second predetermined value (36V) (S11). The second predetermined value (36V) is a value higher than the threshold for over-discharge protection of the battery pack 7. If the battery voltage is equal to or greater than the second predetermined value (36V) (Yes in S11), the calculation unit 42 drives the motor 3 in the reverse direction (S3).

[0055] The calculation unit 42 continues driving the motor 3 in the reverse direction until it counts two peak values ​​of the motor current equal to or greater than 24 A (No in S13). When it counts two peak values ​​of the motor current equal to or greater than 24 A (Yes in S13), that is, when the motor stop condition is satisfied, the calculation unit 42 waits for a predetermined time (200 ms) to elapse (S14), and then stops the motor 3 (S15).

[0056] If the battery voltage is not equal to or greater than the second predetermined value (36 V) in S11 (No in S11), the calculation unit 42 determines that the motor 3 cannot be driven (S16) and does not drive the motor 3. In this case, the calculation unit 42 may notify the user by displaying a message on the operation panel 20, etc.

[0057] In the second control example shown in FIG. 9, when the battery voltage is between 36V and 38V, the motor 3 is stopped after a predetermined time (200 ms) has elapsed since the motor current peak value of 24A or more was counted twice. This widens the range of battery voltage required for fastening work compared to the first control example, while preventing the fastening torque from falling short of the specified value due to a drop in the voltage of the battery pack 7.

[0058] The flowchart in FIG. 9 can be applied to panel drive wrench mode by changing the contents of S4 and S13, i.e., the motor stop conditions, and can also be applied to universal socket mode by changing the motor rotation direction in S3 and S12 to forward rotation.

[0059] FIG. 10 is a flowchart showing a third control example in the foundation drive wrench mode. When the trigger switch 6 is turned on (S1), the calculation unit 42 checks whether the duty of the PWM signal (hereinafter, "duty") applied to the inverter circuit 45 was 100% in the drive control of the motor 3 (hereinafter, "previous motor drive control") in response to the previous on-operation of the trigger switch 6 (motor drive operation) (S2a). Because the calculation unit 42 controls the motor 3 at a constant speed, the fact that the duty was 100% in the previous motor drive control is information indicating a drop in battery voltage and is an example of a predetermined condition related to a voltage drop in the battery pack 7. Note that instead of 100%, any value close to 100% may be used. If the duty was not 100% in the previous motor drive control (No in S2a), the calculation unit 42 drives the motor 3 in the reverse direction at a constant speed of, for example, 8,000 rpm (S3a).

[0060] The calculation unit 42 continues driving the motor 3 in the reverse direction until it counts two peak values ​​of 24 A or more in the motor current (No in S4). If the calculation unit 42 counts two peak values ​​of 24 A or more in the motor current (Yes in S4), that is, if the motor stop condition is met, it stops the motor 3 (S5). If the duty was 100% in the previous motor drive control in S2a (Yes in S2a), the calculation unit 42 determines that it is not possible to drive the motor 3 (S6) and does not drive the motor 3. In this case, the calculation unit 42 may notify the user by displaying a message on the operation panel 20, for example.

[0061] The flowchart in FIG. 10 can be applied to the panel drive wrench mode by changing the content of S4, i.e., the motor stop condition, and can also be applied to the universal socket mode by changing the motor rotation direction in S3a to forward rotation.

[0062] FIG. 11 is a graph showing an example of the change in motor current over time during work in the foundation drive wrench mode. FIG. 12 is a graph showing an example of the change in motor rotation speed over time during work in the foundation drive wrench mode. The motor current and motor rotation speed have waveforms that repeat peaks and valleys in opposite phases each time the hammer 8 strikes the anvil 10. When a motor current peak value of 24 A or more appears twice, the motor 3 stops, and the motor current and motor rotation speed become zero. Although not shown, in the panel drive wrench mode and universal socket mode, the motor current and motor rotation speed also have waveforms that repeat peaks and valleys in opposite phases each time the hammer 8 strikes the anvil 10. When a motor current peak value above each threshold appears twice, the motor 3 stops, and the motor current and motor rotation speed become zero.

[0063] According to this embodiment, the following effects can be achieved.

[0064] (1) The calculation unit 42 switches the rotation direction of the motor 3 based on the type of tool bit detected by the Hall sensor 19. Specifically, when a foundation drive wrench 16 or a panel drive wrench 17 is attached to the anvil 10, the calculation unit 42 switches the motor rotation direction and the anvil rotation direction to reverse even if the rotation instruction direction is forward. This switches the rotation direction of the output shaft 16b of the foundation drive wrench 16 or the output shaft 17b of the panel drive wrench 17 to forward. Therefore, the user can tighten bolts using the foundation drive wrench 16 or the panel drive wrench 17 while keeping the forward / reverse switching lever 13 selected. This eliminates the need for the user to switch the forward / reverse switching lever 13 to reverse when the tool bit is the foundation drive wrench 16 or the panel drive wrench 17, thereby improving workability. When the tool bit is a universal socket 18, the motor rotation direction and the anvil rotation direction are the same as the rotation instruction direction, and the rotation direction of the output shaft 18b of the universal socket 18 is also the same as the rotation instruction direction. Therefore, the user can tighten bolts using the universal socket 18 while keeping the forward / reverse switching lever 13 selected for forward rotation.

[0065] (2) The calculation unit 42 sets the motor stop condition (at least one of the threshold value and the predetermined number of times) for each drive mode, based on the condition that the motor current peak value is equal to or greater than the threshold value. Therefore, in each drive mode, tightening can be completed near the specified torque for the target work, improving workability.

[0066] (3) When a predetermined condition related to a voltage drop in the battery pack 7 is satisfied, the calculation unit 42 does not drive the motor 3 even when the trigger switch 6 is turned on (FIG. 8 or FIG. 10), or provides a predetermined waiting time (200 ms) between the satisfaction of the motor stop condition and the stopping of the motor 3 (FIG. 9). This prevents the tightening torque from falling short of the specified value due to a voltage drop in the battery pack 7. Note that when a predetermined condition related to a voltage drop in the battery pack 7 is satisfied, the calculation unit 42 may at least one of increase the threshold value of the motor stop condition and increase the predetermined number of times, instead of or in addition to providing a predetermined waiting time (200 ms) between the satisfaction of the motor stop condition and the stopping of the motor 3. In this case, it is also possible to prevent the tightening torque from falling short of the specified value due to a voltage drop in the battery pack 7.

[0067] (Embodiment 2) 13 to 17 relate to a work machine 1A according to a second embodiment of the present invention, and a work machine system including the work machine 1A and an external device 80A. In the work machine 1A, the operation panel 20 of the work machine 1 of the first embodiment is replaced with an operation panel 20A. The following description will also refer to FIG. 6 as necessary.

[0068] The battery pack 7 and external device 80A have a short-range wireless communication function such as Bluetooth (registered trademark). The calculation unit 42 of the work machine 1A can communicate with the external device 80A via short-range wireless communication using the short-range wireless communication function of the battery pack 7. The short-range wireless communication function may be provided in the main body of the work machine 1A (a portion excluding the battery pack 7). The external device 80A is a portable device such as a smartphone or tablet terminal. An application (hereinafter referred to as a "setting app" in this embodiment) that can configure various settings for the work machine 1A is installed in the external device 80A.

[0069] As shown in FIG. 13(B), the operation panel 20A has a mode selector switch 21 and a mode display LED 22. The mode selector switch 21 is a mode selection unit that allows the user to manually select the drive mode of the motor 3 controlled by the calculation unit 42 from among a foundation drive wrench mode, a panel drive wrench mode, and a universal socket mode. In other words, the mode selector switch 21 is a tool selection unit that allows the user to manually select the tool to be attached to the anvil 10 from among a foundation drive wrench 16, a panel drive wrench 17, and a universal socket 18. The mode display LED 22 is a mode display unit that displays the current drive mode.

[0070] In the work machine 1 of the first embodiment, the calculation unit 42 automatically selected the drive mode based on the type of tool bit detected by the Hall sensor 19. In the work machine 1A of the present embodiment, the user manually selects the drive mode using the mode selector switch 21. For this reason, the work machine 1A does not require the tool bit detection board 12, Hall sensor 19, and tool bit detection circuit 35 that were present in the work machine 1. Note that the work machine 1A may also retain the function of automatically selecting the drive mode based on the type of tool bit detected by the Hall sensor 19, while allowing the user to manually select the drive mode using the mode selector switch 21 in preference to this.

[0071] 13(C) shows a setting screen of the setting application for external device 80A. On this setting screen, the motor stop conditions can be changed for each drive mode. The relationship between operations on this setting screen and the motor stop conditions will be described later with reference to FIGS. 15 to 17.

[0072] Fig. 14 is a drive mode transition diagram of the work machine 1A (calculation unit 42) in response to operation of the mode selector switch 21. The types and contents of the drive modes are the same as those shown in Fig. 7. Each time the mode selector switch 21 is operated (pressed), the calculation unit 42 transitions in order, for example, between foundation drive wrench mode, panel drive wrench mode, universal socket mode, foundation drive wrench mode, and so on.

[0073] That is, the calculation unit 42 is configured to be able to switch the motor rotation direction and the anvil rotation direction based on the type of tool tip selected by the mode selector switch 21 (the drive mode selected by the mode selector switch 21) regardless of the rotation command direction. The calculation unit 42 is also configured to be able to switch the motor stop condition (at least one of a threshold value and a predetermined number of times) based on the type of tool tip selected by the mode selector switch 21. In this way, the calculation unit 42 can switch the control of the motor 3 based on the type of tool tip selected by the mode selector switch 21.

[0074] Fig. 15 is an explanatory diagram of changes in motor stop conditions according to a power selection by the setting app in foundation drive wrench mode. Fig. 16 is an explanatory diagram of changes in motor stop conditions according to a power selection by the setting app in panel drive wrench mode. Fig. 17 is an explanatory diagram of changes in motor stop conditions according to a power selection by the setting app in universal socket mode.

[0075] The setting app allows the motor stop condition to be changed in five stages for each drive mode. When power 1 is selected by the setting app, the calculation unit 42 sets the predetermined number of times for the motor stop condition to two. When power 2 is selected by the setting app, the calculation unit 42 sets the predetermined number of times for the motor stop condition to three. When power 3 is selected by the setting app, the calculation unit 42 sets the predetermined number of times for the motor stop condition to four. When power 4 is selected by the setting app, the calculation unit 42 sets the predetermined number of times for the motor stop condition to five. When power 5 is selected by the setting app, the calculation unit 42 sets the predetermined number of times for the motor stop condition to six.

[0076] In this way, the calculation unit 42 can switch the tightening torque (power) by communicating with the setting app of the external device 80A, i.e., by changing the predetermined number of times of the motor stop condition in accordance with the power selection by the setting app. The calculation unit 42 may be able to switch the tightening torque (power) by changing the threshold value of the motor stop condition instead of or in addition to the predetermined number of times of the motor stop condition in communication with the setting app of the external device 80A.

[0077] Other aspects of this embodiment are the same as those of the first embodiment. This embodiment can also achieve the same effects as those of the first embodiment. Furthermore, according to this embodiment, the motor stop conditions for each drive mode can be changed using the setting app, which allows for flexible responses to the situation at the work site and improves workability. Note that the function of changing the motor stop conditions for each drive mode using the setting app may be added to the work machine 1 of the first embodiment. The function of changing the motor stop conditions for each drive mode using the setting app may be omitted from the work machine 1A.

[0078] (Embodiment 3) 18 to 22 relate to a work machine 1B according to a third embodiment of the present invention, and a work machine system made up of the work machine 1B and an external device 80B. In the work machine 1B, the operation panel 20 of the work machine 1 of the first embodiment is replaced with an operation panel 20A. The following description will also refer to FIG. 6 as necessary.

[0079] The battery pack 7 and external device 80B have a short-range wireless communication function such as Bluetooth (registered trademark). The calculation unit 42 of the work machine 1B can communicate with the external device 80B via short-range wireless communication using the short-range wireless communication function of the battery pack 7. The short-range wireless communication function may be provided in the main body of the work machine 1B (a portion excluding the battery pack 7). The external device 80B is a portable device such as a smartphone or tablet terminal. An application (hereinafter referred to as a "setting app" in this embodiment) that can configure various settings of the work machine 1B is installed in the external device 80B.

[0080] As shown in Fig. 18(B), the operation panel 20B has a power changeover switch 25 as a changeover operation unit, and a power display LED 26. The power changeover switch 25 is a power selection unit that allows the user to change the power in the current drive mode between five levels. The power display LED 26 is a power display unit that displays the power in the current drive mode. Changing the motor stop conditions by operating the power changeover switch 25 will be described later with reference to Figs. 20 to 22.

[0081] 18(C) shows a setting screen of the setting application of the external device 80B. On this setting screen, the drive mode of the motor 3 by the calculation unit 42 can be selected from among a foundation drive wrench mode, a panel drive wrench mode, and a universal socket mode. In other words, on this setting screen, the user can manually select the tip tool to be attached to the anvil 10 from among a foundation drive wrench 16, a panel drive wrench 17, and a universal socket 18.

[0082] In the work machine 1 of the first embodiment, the calculation unit 42 automatically selected the drive mode based on the type of tool bit detected by the Hall sensor 19. In the work machine 1B of the present embodiment, the user manually selects the drive mode using a setting app in the external device 80B. Therefore, the work machine 1B does not require the tool bit detection board 12, Hall sensor 19, and tool bit detection circuit 35 that were present in the work machine 1. Note that the work machine 1B may also retain the function of automatically selecting the drive mode based on the type of tool bit detected by the Hall sensor 19, while allowing the user to manually select the drive mode using the setting app in the external device 80B in preference to this.

[0083] FIG. 19 is a drive mode transition diagram of the work machine 1B (calculation unit 42) according to selection in the setting app. The types and contents of the drive modes are the same as those shown in FIG. 7. When "for foundation anchor" is selected in the setting app, the calculation unit 42 transitions to the foundation drive wrench mode. When "for panel" is selected in the setting app, the calculation unit 42 transitions to the panel drive wrench mode. When "for column / beam" is selected in the setting app, the calculation unit 42 transitions to the universal socket mode.

[0084] That is, the calculation unit 42 is configured to be able to switch the motor rotation direction and the anvil rotation direction based on the type of tool tip selected in the setting app of the external device 80B (the drive mode selected by the setting app), i.e., the type of tool tip input from the external device 80B, regardless of the rotation instruction direction. The calculation unit 42 is also configured to be able to switch the motor stop condition (at least one of a threshold value and a predetermined number of times) based on the type of tool tip selected in the setting app of the external device 80B. In this way, the calculation unit 42 can switch the control of the motor 3 based on the type of tool tip selected in the setting app of the external device 80B.

[0085] Fig. 20 is an explanatory diagram of changes in motor stop conditions in response to operation of the power selector switch 25 in the foundation drive wrench mode. Fig. 21 is an explanatory diagram of changes in motor stop conditions in response to operation of the power selector switch 25 in the panel drive wrench mode. Fig. 22 is an explanatory diagram of changes in motor stop conditions in response to operation of the power selector switch 25 in the universal socket mode.

[0086] The power selector switch 25 can change the motor stop condition in five stages for each drive mode. Each time the power selector switch 25 is operated (pressed), the calculation unit 42 changes the predetermined number of times of the motor stop condition, for example, 2 times, 3 times, 4 times, 5 times, 6 times, 2 times, ... in order.

[0087] In this way, the calculation unit 42 can switch the tightening torque (power) by changing the predetermined number of times of the motor stop condition in accordance with the power selection made by the power selector switch 25. The calculation unit 42 may be able to switch the tightening torque (power) by changing the threshold value of the motor stop condition in accordance with the power selection made by the power selector switch 25, instead of or in addition to the predetermined number of times.

[0088] Other aspects of this embodiment are the same as those of the first embodiment. This embodiment can also achieve the same effects as those of the first embodiment. Furthermore, according to this embodiment, the motor stop conditions for each drive mode can be changed using the power selector switch 25, which allows for flexible responses according to the situation at the work site and improves workability. Note that the function of changing the motor stop conditions for each drive mode using the power selector switch 25 may be added to the work machines 1 and 1A of the first and second embodiments.

[0089] The present invention has been described above using embodiments as examples, but it will be understood by those skilled in the art that various modifications can be made to each component and each processing process of the embodiments within the scope of the claims.

[0090] For example, the work machine of the present invention is not limited to a cordless type that operates on power from a battery pack, but may also be a corded type that operates on power from an external AC power source. The battery voltage, motor rotation speed, duty, threshold and predetermined number of times for motor stop conditions, number of settable power levels, etc., which are given as specific numerical examples in the embodiments, do not in any way limit the scope of the invention and can be changed as desired to suit the required specifications. [Explanation of symbols]

[0091] 1...Work machine, 2...Housing, 2a...Body part, 2b...Handle part, 2c...Battery pack mounting part, 3...Motor (drive part), 3a...Motor shaft, 4...Reduction mechanism, 5...Spindle, 6...Trigger switch (drive operation part), 7...Battery pack, 8...Hammer, 9...Spring, 10...Anvil (tip tool mounting part), 11...Hammer case, 12...Tip tool detection board, 13...Forward / reverse switching lever (rotation direction switching part), 14...Mounting bracket, 15...Sensor / inverter board, 16...Foundation drive wrench, 16a...Gear, 16b...Output shaft, 16c...Magnet, 17...Panel drive wrench, 17a...Gear, 17b...Output shaft, 17c...Magnet, 18...Universal socket, 18a...Shaft, 18 b...output shaft, 19...Hall sensor (tool tip detection sensor), 20...operation panel (switch panel), 21...mode changeover switch (mode selection section), 22...mode display LED, 25...power changeover switch (power selection section), 26...power display LED (power display section), 30...control board, 31...current detection circuit, 33...switch operation detection circuit, 34...rotation direction setting circuit, 35...tool tip detection circuit, 36...operation panel circuit, 37...control signal output circuit, 38...rotation position detection circuit, 39...rotation speed detection circuit, 40...mode setting detection circuit, 41...strength setting detection circuit, 42...calculation section (control section), 43...Hall IC (motor rotation position sensor), 45...inverter circuit, 80A, 80B...external device.

Claims

1. A drive unit; a tool attachment unit that is driven by the driving force of the drive unit and that can attach a tool; a tool bit detection unit capable of detecting the type of tool bit attached to the tool bit attachment unit; a control unit capable of switching control of the drive unit, The control unit is configured to be able to switch the rotation direction of the drive unit based on the type of the tool bit detected by the tool bit detection unit.

2. a rotation direction switching unit that can switch between forward and reverse rotation of the drive unit; The work machine according to claim 1 , wherein the control unit is capable of switching the rotation direction of the drive unit based on the type of the tool bit, regardless of the rotation direction selected by the rotation direction switching unit.

3. a current detection unit that detects a current flowing in the drive unit; The work machine according to claim 1 or 2, wherein the control unit is capable of stopping the drive unit when the current exceeds a threshold value a predetermined number of times, and is capable of changing the threshold value based on the type of the tool bit.

4. The work machine according to claim 3 , wherein the control unit is capable of changing the predetermined number of times based on the type of the tool bit.

5. The work machine according to claim 3 or 4, further comprising a change operation unit that allows manual change of at least one of the threshold value and the predetermined number of times.

6. The work machine according to claim 3 or 4, wherein at least one of the threshold value and the predetermined number of times is changeable through communication with an external device.

7. a battery pack attachment section to which a battery pack can be attached and detached; a drive operation unit that can switch between driving and stopping the drive unit, 7. The work machine according to claim 3, wherein, when a predetermined condition related to a voltage drop of the battery pack attached to the battery pack attachment section is satisfied, the control section performs at least one of the following changes: increasing the threshold value; increasing the predetermined number of times; or lengthening the waiting time between when the current exceeds the threshold value a predetermined number of times and when the drive section is stopped.

8. a battery pack attachment section to which a battery pack can be attached and detached; a drive operation unit that can switch between driving and stopping the drive unit, 7. The work machine according to claim 1, wherein the control unit does not start the drive unit even if a drive instruction operation is performed on the drive operation unit when a predetermined condition related to a voltage drop of the battery pack attached to the battery pack attachment unit is satisfied.

9. The work machine according to claim 7 or 8, wherein the predetermined condition includes that the voltage of the battery pack attached to the battery pack attachment portion is equal to or lower than a predetermined value higher than a threshold value for over-discharge protection of the battery pack when the drive unit is not being driven.

10. the control unit controls the drive unit at a constant speed by PWM control, The work machine according to claim 7 or 8, wherein the predetermined condition includes a condition that a duty ratio of the PWM control in a previous drive control of the drive unit is equal to or greater than a predetermined value.

11. a rotary impact mechanism that converts the driving force of the drive unit into a rotary impact force and applies the rotary impact force to the tool attachment unit, The work machine according to claim 1 , wherein the tool attachment portion includes a universal socket and a drive wrench.

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