Electric working machine

Abstract

To provide an electric work machine that is further excellent in operability.SOLUTION: An electric work machine according to one aspect of the disclosure comprises a motor, an operation part and a control part. The control part switches between validity and invalidity of a specific mode in which a rotation speed of the motor is increased when detecting a load of the motor, on the basis of a predetermined signal being received. The control part changes a rotation speed corresponding to an operation amount of the operation part, in a speed area where a rotation speed is changed in accordance with the operation amount of the operation part, between when the specific mode is valid and when the mode is invalid.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to an electric work machine. [Background technology]

[0002] The electric power tool described in Patent Document 1 has a soft no-load function. When the soft no-load function is executed, the electric power tool drives the motor at a constant predetermined speed slower than a set target speed until the tool receives a load. When the tool receives a load, the electric power tool accelerates the motor and drives it at the target speed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-202568 A Summary of the Invention [Problem to be solved by the invention]

[0004] There are power tools that are equipped with a trigger and change the motor speed according to the amount of pulling of the trigger. It is conceivable to add a soft no-load function to such power tools. In this case, the user can adjust the motor speed by the trigger when the soft no-load function is disabled, but cannot adjust the motor speed by the trigger when the soft no-load function is enabled. Therefore, the user may feel that the operability of the power tool is insufficient.

[0005] One aspect of the present disclosure provides an electric operating machine with improved operability. [Means for solving the problem]

[0006] An electric operating machine according to one aspect of the present disclosure includes a motor, an operating unit, and a control unit. The operating unit is operated to drive the motor. The control unit is configured to control the rotation speed of the motor in response to the operation of the operating unit. The control unit is configured to switch between enabling and disabling a specific mode in which the rotation speed of the motor is increased when a load on the motor is detected, based on receipt of a predetermined signal. The control unit is configured to change the rotation speed corresponding to the operation amount of the same operating unit in a speed region in which the rotation speed changes in response to the operation amount of the operating unit, between enabling and disabling the specific mode.

[0007] The above-mentioned electric operating machine can change the rotation speed according to the amount of operation of the operating unit even when the specific mode is enabled. Furthermore, the rotation speed for the same amount of operation differs between when the specific mode is enabled and when it is disabled. Therefore, the user can intuitively switch between the enabled and disabled states of the specific mode. Therefore, an electric operating machine with better operability can be realized. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram showing the appearance of an electric operating machine according to a first embodiment. FIG. [Diagram 2] FIG. 2 is a block diagram showing the electrical configuration of the electric operating machine according to the first embodiment. [Diagram 3] The first map shows the rotation speed command values ​​for the trigger pull amount and dial position when the soft no load is enabled, and the second map shows the rotation speed command values ​​for the trigger pull amount and dial position when the soft no load is disabled. [Figure 4] 11 is a graph showing the rotation speed command value versus the trigger pull amount when the soft no-load control according to the first embodiment is enabled and disabled. [Diagram 5] 5 is a flowchart showing a processing procedure of a motor driving process according to the first embodiment. [Figure 6]6 is a time chart showing the microcomputer power supply, the main power switch, the on / off of the trigger, the target value of the rotation speed, the trigger pull amount, the soft no-load setting, and the motor drive state. [Figure 7] 13 is a graph showing the rotation speed command value versus the trigger pull amount when soft no-load is enabled according to the second embodiment. [Figure 8] 13 is a graph showing the rotation speed command value versus the trigger pull amount when soft no-load is disabled according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [Summary of the embodiment] An electric operating machine in one embodiment may include a motor, an operating unit, and a control unit.

[0010] The electric working machine in one embodiment may further include a storage unit. The storage unit may store a first correspondence relationship between an operation amount of the operating unit and a first rotation speed, and a second correspondence relationship between an operation amount of the operating unit and a second rotation speed. The first rotation speed and the second rotation speed corresponding to the same operation amount of the operating unit may be different. The control unit may be configured to detect a load on the motor. The control unit may be configured to control the rotation speed to a first rotation speed that has an upper limit of a predetermined speed and is based on the first correspondence relationship and the operation amount of the operating unit, before the load is detected, when the specific mode is enabled. The control unit may be configured to control the rotation speed to a second rotation speed that is based on the second correspondence relationship and the operation amount of the operating unit, when the specific mode is disabled. The electric working machine in one embodiment may have any of these features deleted.

[0011] In an embodiment of an electric working machine having all of these features, when the specific mode is enabled, the user can manually change the rotation speed until the rotation speed reaches a predetermined speed before a load is detected. Therefore, when the specific mode is enabled, the user can manually adjust the rotation speed in the low-speed range to position the electric working machine relative to a work target. Also, when the specific mode is disabled, the user can manually change the rotation speed regardless of whether a load is detected or not.

[0012] The electric operating machine in an embodiment may further include a setting unit. The setting unit may be operated to set a target value of the rotation speed. The predetermined speed may correspond to the lower of the target value set via the setting unit and a pre-set no-load speed. The second correspondence relationship may include a plurality of third correspondence relationships that differ for each target value. The second rotation speed may have the target value as an upper limit, and may be based on one of the plurality of third correspondence relationships corresponding to the target value set via the setting unit and the operation amount of the operation unit.

[0013] In one embodiment, when the specific mode is disabled, the second rotation speed is based on one of a plurality of third correspondence relationships corresponding to the set target value, and therefore, when the specific mode is disabled, the user can manually adjust the rotation speed for each target value.

[0014] The first correspondence relationship may be constant regardless of the target value. Additionally / alternatively, the control unit may be configured to control the rotation speed to a third rotation speed based on the first correspondence relationship and the operation amount of the operation unit, with the target value as an upper limit, after the load is detected, when the specific mode is enabled.

[0015] In the case where the first correspondence relationship is constant regardless of the target value and the control unit is configured to control the rotation speed to a third rotation speed with the target value as the upper limit and based on the first correspondence relationship and the operation amount of the operation unit when the specific mode is enabled, after the load is detected, the rotation speed of the motor is controlled based on the constant first correspondence relationship regardless of the target value after the load is detected. Therefore, when the specific mode is enabled, the user can manually change the rotation speed at the same rate of change regardless of the target value. In other words, when the specific mode is enabled, the burden on the user of adjusting the rotation speed can be reduced, and operability can be improved.

[0016] The control unit may be configured to control the rotation speed to the target value set via the setting unit after the load is detected when the specific mode is enabled. When the specific mode is enabled, the motor of such an electric working machine automatically rotates at the target speed after detecting a load, regardless of the amount of operation of the operating unit, so that the user can work with the electric working machine without adjusting the rotation speed when the specific mode is enabled.

[0017] The control unit may be configured to continue controlling the rotation speed to the third rotation speed if, when the specific mode is enabled, the load is no longer detected after the load is detected. In such an electric operating machine, once a load is detected, the rotation speed can be controlled to the third rotation speed even if the load is no longer detected, and therefore, even if the load temporarily decreases during work, a decrease in the rotation speed can be suppressed.

[0018] The control unit may be configured to continue to control the rotation speed to the target value when the particular mode is active and then when the load is no longer detected. In such an electric work machine, once a load is detected, the rotation speed can be controlled to the target value even if the load is no longer detected. Therefore, even if the load temporarily decreases during work, the motor rotation speed can be prevented from decreasing.

[0019] In some embodiments, the above-mentioned features may be combined in any combination, and in some embodiments, any of the above-mentioned features may be omitted. Specific Exemplary Embodiments Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings.

[0020] 1. First embodiment <1-1. Configuration> The configuration of an electric operating machine 10 according to a first embodiment will be described with reference to Fig. 1. The electric operating machine 10 according to this embodiment is a jigsaw.

[0021] The electric work machine 10 includes a housing 11. The housing 11 supports a tool 15. The tool 15 is a saw blade (i.e., a jigsaw blade) and is supported in the housing 11 so as to be capable of reciprocating motion. The housing 11 also accommodates a motor 50 and various circuits, which will be described later. The motor 50 is mechanically connected to the tool 15. The speed of the reciprocating motion of the tool 15 changes according to the rotational speed of the motor 50, and increases as the speed of the motor 50 increases.

[0022] The housing 11 also includes a connection portion 18. A battery pack 20 is connected to the connection portion 18. The battery pack 20 includes a battery that can be repeatedly charged and discharged. The battery includes a plurality of battery cells, and is, for example, a lithium ion battery.

[0023] In addition, a main power switch 13 is provided in the housing 11. The main power switch 13 is a tactile switch configured to be operated (specifically, pressed) by a user. Each time the main power switch 13 is operated, the power of various circuits is switched on and off.

[0024] The housing 11 is also provided with a trigger 12. The trigger 12 is configured to be operated by a user. Specifically, the trigger 12 is configured to be pulled by a user. The trigger 12 is configured to be displaced from a first position to a second position. When the power of various circuits is on, the motor 50 is driven when the user pulls the trigger 12. In a predetermined drive mode, the rotation speed of the motor 50 changes according to the pulling amount of the trigger 12. In this embodiment, the pulling amount of the trigger 12 is indicated by 12 trigger levels, 0, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, and 20. The pulling amount of the trigger 12 is not limited to 12 levels, and may be indicated by multiple trigger levels. For example, the pulling amount of the trigger 12 may be indicated by 10 or 20 trigger levels. The trigger level increases according to the increase in the pulling amount of the trigger 12. In this embodiment, the trigger 12 corresponds to an example of an operation unit of the present disclosure.

[0025] The housing 11 is also provided with a speed adjustment dial 14. The speed adjustment dial 14 is configured to be operated by a user to set a target value for the rotation speed of the motor 50. The speed adjustment dial 14 is a rotating member, and numbers from "1" to "5" are attached along its circumferential surface, and one of five target values ​​is set via the speed adjustment dial 14. The number of numbers attached to the speed adjustment dial 14 is not limited to five, but may be two or more. The number of target values ​​set via the speed adjustment dial 14 is not limited to five, but may be two or more, for example, may be ten or twenty. The speed adjustment dial 14 outputs a target value corresponding to the dial position relative to a designated position on the housing 11 (a position marked with a triangle in FIG. 1) to the microcomputer 30. The speed adjustment dial 14 is configured to rotate and move between a first limit position and a second limit position. At the first limit position, "1" is located at the designated position on the housing 11. At the second limit position, "5" is located at the designated position. In this embodiment, the speed adjustment dial 14 corresponds to an example of a setting unit in the present disclosure. Note that the speed adjustment dial 14 may be, for example, a sliding speed adjustment slide.

[0026] The speed adjustment dial 14 is operated by the user to switch between the first drive mode and the second drive mode. The drive mode switching operation is an operation of moving the speed adjustment dial 14 back and forth between the first limit position and the second limit position. That is, the drive mode switching operation is an operation of moving the speed adjustment dial 14 from the first limit position to the second limit position and then returning it to the first limit position, or an operation of moving the speed adjustment dial 14 from the second limit position to the first limit position and then returning it to the second limit position. Such a back and forth operation is not usually expected as an operation for setting a target value. Therefore, unintended switching of the drive mode by the user is suppressed.

[0027] The first drive mode is a drive mode in which the soft no-load is effective. The second drive mode is a drive mode in which the soft no-load is ineffective. The soft no-load is a function provided in the electric working machine 10, and drives the motor 50 at a predetermined speed as an upper limit until a load acts on the motor 50 (i.e., until a load on the motor 50 is detected), and increases the rotation speed of the motor 50 when a load acts on the motor 50 (i.e., when a load on the motor 50 is detected). The predetermined speed is the lower value of the set target value of the rotation speed and the soft no-load speed. The soft no-load speed is a speed that is set in advance and is a relatively low speed. In other words, when the soft no-load is effective, an increase in the rotation speed of the motor 50 is suppressed until a load acts on the motor 50. This suppresses the vibration of the electric working machine 10 and the reaction force from the work object when the user positions the electric working machine 10 relative to the work object (e.g., wood). This makes it easier to position the electric working machine 10. In this embodiment, the soft no-load corresponds to an example of a specific mode, and the soft no-load speed corresponds to an example of a no-load speed of the present disclosure.

[0028] Next, the electrical configuration of the electric working machine 10 will be described with reference to Fig. 2. The electric working machine 10 includes a motor 50. The motor 50 is a brushless motor including coils for three phases, U-phase, V-phase, and W-phase.

[0029] The electric operating machine 10 also includes a position sensor 51. The position sensor 51 includes three Hall ICs arranged corresponding to the stators of the respective phases of the motor 50. The Hall ICs output a rotation detection signal to a position detection circuit 52, which will be described later, every time the rotor of the motor 50 rotates a predetermined angle.

[0030] The electric operating machine 10 also includes a switch unit 130. The switch unit 130 includes a main power supply setting unit 13a. The main power supply setting unit 13a outputs a first power supply on signal or a first power supply off signal to a power supply circuit 41 and a switch input determination unit 320 (described later) in response to operation of the main power supply switch 13. The signal output from the main power supply setting unit 13a switches between the first power supply on signal and the first power supply off signal every time the main power supply switch 13 is operated.

[0031] The switch unit 130 includes a first speed setting unit 14a. The first speed setting unit 14a includes a sliding resistor, and outputs a first resistance value signal indicating a first resistance value corresponding to the dial position of the speed adjustment dial 14 to a speed command calculation unit 310, which will be described later.

[0032] The switch unit 130 includes a second speed setting unit 12a. The second speed setting unit 12a outputs a second power-on signal to the switch input determination unit 320 in response to the pulling amount of the trigger 12 being equal to or greater than a predetermined pulling amount. The second speed setting unit 12a also outputs a second power-off signal to the switch input determination unit 320 in response to the pulling amount of the trigger 12 being less than the predetermined pulling amount. The second speed setting unit 12a also includes a sliding resistor, and outputs a second resistance value signal indicating a second resistance value corresponding to the pulling amount of the trigger 12 to the speed command calculation unit 310.

[0033] The electric work machine 10 also includes a work machine circuit 100. The work machine circuit 100 includes a power supply circuit 41. The power supply circuit 41 is connected to the battery pack 20. When a first on signal is input, the power supply circuit 41 generates a predetermined power supply voltage Vcc from the input power and supplies the power supply voltage Vcc to various circuits in the work machine circuit 100, such as the microcomputer 30.

[0034] The work machine circuit 100 includes a motor driver 42. The motor driver 42 is a three-phase full bridge circuit including three switching elements provided on the high side and three switching elements provided on the low side. The motor driver 42 is connected between the battery pack 20 and the motor 50, receives power from the battery pack 20, and passes a current through the windings of each phase of the motor 50. Each switching element of the motor driver 42 is turned on or off in response to a control command output from a microcomputer 30, which will be described later.

[0035] The work machine circuit 100 includes a current detection circuit 43. The current detection circuit 43 detects the value of a current flowing through the motor 50, and outputs a detection signal corresponding to the detected current value to a current change detection unit 370, which will be described later.

[0036] The work machine circuit 100 includes a position detection circuit 52. The position detection circuit 52 detects the rotational position of the rotor of the motor 50 based on a rotation detection signal input from the position sensor 51. The position detection circuit 52 outputs a position signal to the microcomputer 30 according to the detected rotational position.

[0037] The working machine circuit 100 includes a microcomputer 30. The microcomputer 30 includes a CPU 30a, a ROM 30b, a RAM 30c, an I / O, and the like. Various functions of the microcomputer 30 are realized by the CPU 30a executing a program stored in a non-transitive real recording medium. In this embodiment, the ROM 30b corresponds to the non-transitive real recording medium. By executing this program, a method corresponding to the program is executed. Note that a part or all of the functions executed by the CPU 30a may be configured in hardware form using one or more ICs or the like. Also, the microcomputer 30 may be configured from a single microcomputer, or may be configured from a plurality of microcomputers. The ROM 30b stores a first map and a second map, which will be described later. Also, the ROM 30b stores a setting of whether the soft no-load is enabled or disabled. Note that in this embodiment, the ROM 30b corresponds to an example of a storage unit of the present disclosure.

[0038] The microcomputer 30 includes, as various functions, a speed command calculation unit 310, a switch input determination unit 320, a soft no-load enable / disable determination unit 330, a pulse width modulation generation unit (hereinafter, PWM generation unit) 340, a drive control unit 350, a soft no-load detection unit 360, a current change detection unit 370, a rotation speed calculation unit 390, and a display control unit 380. In this embodiment, the microcomputer 30 includes all of the above-mentioned various functions, but in another embodiment, one or more of the above-mentioned various functions may be omitted.

[0039] The speed command calculation unit 310 calculates a rotation speed command value based on the input first resistance value signal and second resistance value signal and the first map or the second map. That is, the speed command calculation unit 310 calculates the rotation speed command value based on the dial position of the speed adjustment dial 14, the pull amount of the trigger 12, and the first map or the second map.

[0040] The first map shows a first correspondence relationship between the trigger pull amount and the rotation speed command value.The second map shows a second correspondence relationship between the trigger pull amount and the rotation speed command value. The first map is used when the soft no-load is enabled. An example of the first map is shown in FIG. 3. In the first map, the command value increases as the trigger pull amount increases, and when the command value reaches the target value, the command value becomes constant even if the trigger pull amount increases. In the first map, even if the target value is different, the correspondence relationship between the trigger pull amount and the rotation speed command value is the same. In other words, even if the target value is different, the same command value is calculated for the same pull amount until the command value reaches the target value.

[0041] For example, when the dial position is "2", 1300 (rpm) is set as the target value, and when the dial position is "4", 2500 (rpm) is set as the target value. In both cases where the dial position is "2" and "4", the command value increases at the same rate as the trigger pull amount increases until the trigger level reaches 0 to 7. When the dial position is "2", the command value reaches the target value when the trigger level reaches 9, and the command value is fixed at the target value when the trigger level is in the range of 9 to 20. On the other hand, when the dial position is "4", the command value increases as the trigger pull amount increases until the trigger level reaches 15. When the trigger level reaches 17, the command value reaches the target value, and the command value is fixed at the target value when the trigger level is in the range of 17 to 20.

[0042] When the soft no-load is enabled and during execution of the soft no-load (i.e., before load detection), the speed command calculation unit 310 calculates a command value using a first map with a predetermined speed as the upper limit. The predetermined speed is the smaller of the target value and the soft no-load speed. The soft no-load speed is set in advance, and is 1400 (rpm) in this embodiment. Therefore, when the dial position is "1" or "2", the speed command calculation unit 310 calculates a command value using the first map with the target value as the upper limit. Also, when the dial position is "3", "4", or "5", the speed command calculation unit 310 calculates a command value using the first map with the soft no-load speed as the upper limit.

[0043] Furthermore, when the soft no-load is enabled and the soft no-load is released (that is, after a load is detected), the speed command calculation unit 310 calculates a command value using the first map with the target value as the upper limit.

[0044] The second map is used when the soft no-load is disabled. FIG. 3 shows an example of the second map. In the second map, the command value increases as the trigger pull amount increases, and when the command value reaches the target value, the command value becomes constant even if the trigger pull amount increases. The second correspondence relationship includes a plurality of third correspondence relationships that differ for each target value. In the plurality of third correspondence relationships, the command value for the same trigger pull amount increases as the target value increases.

[0045] A graph of the command value versus the trigger pull amount based on the first map and the second map is shown in Fig. 4. As shown in Fig. 4, in this embodiment, the correspondence relationships in the second map when the dial position is "1" to "4" are different from the correspondence relationships in the first map. Also, in this embodiment, the correspondence relationships in the second map when the dial position is "5" are the same as the correspondence relationships in the first map.

[0046] 2, the speed command calculation unit 310 outputs the calculated rotation speed command value to the PWM generation unit 340. In addition, the speed command calculation unit 310 outputs the first resistance value to the soft no load enable / disable determination unit 330.

[0047] When the first power-on signal and the second power-on signal are input, the switch input determination unit 320 outputs a drive-on signal to the PWM generation unit 340, the soft no-load enable / disable determination unit 330, and the display control unit 380. When at least one of the first power-off and the second power-off is input, the switch input determination unit 320 outputs a drive-off signal to the PWM generation unit 340, the soft no-load enable / disable determination unit 330, and the display control unit 380.

[0048] When the drive-off signal is input, the soft no-load enable / disable determination unit 330 determines whether the soft no-load should be switched from enabled to disabled, or from disabled to enabled, if the first resistance value signal indicates a change equivalent to one cycle of the speed adjustment dial 14. In this embodiment, the first resistance value signal indicating a change equivalent to one cycle of the speed adjustment dial 14 corresponds to an example of the predetermined signal.

[0049] When the soft no-load enable / disable determination unit 330 determines a switch from enable to disable, it outputs an enable signal to the PWM generation unit 340 and the display control unit 380. When the soft no-load enable / disable determination unit 330 determines a switch from disable to enable, it outputs an enable signal to the PWM generation unit 340 and the display control unit 380.

[0050] The current change detector 370 detects the amount of change in current and the number of times the current increases based on the input detection signal. The soft no-load detection unit 360 detects a load acting on the motor 50 when the amount of change in current and the number of times the current increases are greater than their respective threshold values. When the soft no-load detection unit 360 detects a load, it outputs a soft no-load release signal to the PWM generation unit 340.

[0051] The rotation speed calculation unit 390 calculates the rotation speed of the motor 50 based on the position signal input from the position detection circuit 52, and outputs the calculation result to the PWM generation unit 340. The PWM generating unit 340 generates a PWM signal for driving the motor 50 so that the rotation speed of the motor 50 becomes equal to a rotation speed command value. In detail, the PWM generating unit 340 generates the PWM signal based on the input rotation speed command value, the input rotation speed calculation result, the input drive-on signal or drive-off signal, the input enable signal or disable signal, and the presence or absence of a soft no-load release signal. The PWM generating unit 340 outputs the generated PWM signal to the drive control unit 350.

[0052] The drive control unit 350 generates a control command based on the PWM signal output from the PWM generation unit 340. The control command commands ON or OFF each switch included in the motor driver 42. The drive control unit 350 outputs the generated control command to the motor driver 42.

[0053] The electric work machine 10 also includes a notification unit 60. The notification unit 60 is an illuminator including at least one light emitting diode (LED). The work machine circuit 100 also includes a display circuit 61. A display control unit 380 controls notification by the notification unit 60 via the display circuit 61 based on an input valid signal or invalid signal and an input drive-on signal or drive-off signal. When an valid signal and a drive-on signal are input, the display control unit 380 notifies the user that the soft no-load is active through the notification unit 60. For example, the display control unit 380 notifies the user that the soft no-load is active by blinking the notification unit 60.

[0054] <1-2. Processing> Next, the procedure of the motor drive process executed by the microcomputer 30 will be described with reference to the flowchart of Fig. 5. The microcomputer 30 starts this process when power is supplied to the microcomputer 30 and the microcomputer is turned on.

[0055] First, in S10, the current soft no-load setting is enabled or disabled. RAM30c Read from . Next, in S20, the elapsed time is counted up. Here, by counting up the elapsed time, the time during which the trigger 12 is maintained in the OFF state is measured.

[0056] Next, in S30, it is determined whether or not a soft no-load switching operation has been performed. If it is determined that a soft no-load switching operation has been performed, the process proceeds to S40. If it is determined that a soft no-load switching operation has not been performed, the process proceeds to S50.

[0057] In S40, the setting of the soft no-load is changed. That is, if the soft no-load is currently set to be enabled, the soft no-load is set to be disabled. RAM30c The software no-load setting is stored in the ROM 30b as an invalid setting. Also, if the software no-load setting is currently set to invalid, the software no-load setting is set to valid, and the valid setting of the software no-load is stored in the ROM 30b. After that, the process proceeds to S50.

[0058] In S50, it is determined whether or not the trigger 12 is in the ON state. That is, it is determined whether or not a second power-on signal is being output from the second speed setting unit 12a. If it is determined that the trigger 12 is in the OFF state, the process proceeds to S60.

[0059] In S60, it is determined whether the elapsed time counted up in S20 is greater than the time threshold value Tth. If it is determined that the elapsed time is equal to or less than the time threshold value Tth, the process returns to S20. If it is determined that the elapsed time is greater than the time threshold value Tth, the process proceeds to S70.

[0060] In S70, the power supply to the microcomputer is turned off, and this process ends. If it is determined in S50 that the trigger 12 is in the ON state, the process proceeds to S80. In S80, in response to the trigger 12 being in the ON state, the count of the elapsed time is cleared, and the process proceeds to S90.

[0061] In S90, it is determined whether or not the soft no-load is currently set to be valid. If it is determined that the soft no-load is set to be valid, the process proceeds to S100. In S100, a command value for the rotation speed of the motor 50 is calculated based on the first map, the first resistance value signal, and the second resistance value signal.

[0062] Next, in S110, it is determined whether or not the soft no-load has been released. In other words, it is determined whether or not a load on the motor 50 has been detected. The load on the motor 50 is a load acting on the motor 50 from a work object. If it is determined that the soft no-load has been released, the process proceeds to S150. If it is determined that the soft no-load has not been released, the process proceeds to S120.

[0063] In S120, it is determined whether the command value calculated in S100 is less than the soft no-load speed. If it is determined that the command value is less than the soft no-load speed, the process proceeds to S150. If it is determined that the command value is equal to or greater than the soft no-load speed, the process proceeds to S130.

[0064] In S130, the soft no-load speed is set as the command value, so that the rotation speed of the motor 50 is suppressed to be equal to or lower than the soft no-load speed during execution of the soft no-load. If it is determined in S90 that the soft no-load is set to disabled, the process proceeds to S140.

[0065] In S140, a command value for the rotation speed of the motor 50 is calculated based on the second map, the first resistance value signal, and the second resistance value signal. Next, in S150, a PWM signal is generated based on the command value calculated in any one of S110, S130, and S140. Then, a control command is generated based on the generated PWM signal, and the generated control command is output to the motor driver 42.

[0066] Next, in S160, it is determined whether or not a soft no-load is being executed. If it is determined that a soft no-load is being executed, the process proceeds to S170. If it is determined that the soft no-load is being released, the process returns to S50.

[0067] In S170, it is determined whether or not to cancel the soft no-load. That is, if a load acting on the motor 50 is detected based on the amount of change in current and the number of times the current increases, it is determined that the soft no-load is to be canceled. If it is determined that the soft no-load is to be canceled, the soft no-load is canceled. That is, the upper limit of the command value is set to the target value. If a load acting on the motor 50 is not detected, the execution of the soft no-load is maintained. Here, once the soft no-load is canceled, the cancellation of the soft no-load is maintained even if a load acting on the motor 50 is not detected thereafter. That is, once the soft no-load is canceled, even if a load acting on the motor 50 is not detected thereafter, the command value is calculated based on the first map with the target value as the upper limit. After the process of S170, the process returns to S50.

[0068] FIG. 6 shows a time chart of the power supply of the microcomputer 30, the main power switch 13, the on / off of the trigger 12, the target value of the rotation speed, the trigger pull amount, the soft no-load setting, and the motor drive state when the motor drive process shown in FIG. 5 is executed.

[0069] At time t1, the main power switch 13 is pressed and a first power-on signal is output, turning on the power of the microcomputer 30. Then, the soft no-load setting (enabled in this case) is read out. The dial position of the speed adjustment dial 14 is set to "5."

[0070] At time t2, the trigger 12 is pulled and a second power-on signal is output, causing the motor 50 to start driving. From time t2 to time t4, the trigger pull amount increases, and from time t4 to time t6, the trigger pull amount is maintained at the maximum amount. From time t2 to time t3, the rotation speed of the motor 50 increases, and at time t3, the rotation speed reaches the no-load speed (low speed). From time t3 to time t5, the rotation speed is maintained at the no-load speed.

[0071] Then, at time t5, a load is detected and the soft no-load is released. With the release of the soft no-load, the rotation speed of the motor 50 increases from the soft no-load speed to a high speed. Between time t6 and time t7, the trigger pull amount decreases, and with the decrease in the trigger pull amount, the rotation speed of the motor 50 decreases. At time t7, the trigger 12 is turned off and a second power-off signal is output.

[0072] Then, at time t8, when the main power switch 13 is pressed and a first power-off signal is output, the power to the microcomputer 30 is turned off. Subsequently, at time t9, when the main power switch 13 is pressed and a first power-on signal is output, the power of the microcomputer 30 is turned on.

[0073] Subsequently, between time t10 and time t11, the speed adjustment dial 14 is operated back and forth once with the trigger 12 in an OFF state. Accordingly, at time t11, the soft no-load is changed from enabled to disabled.

[0074] Subsequently, at time t12, the trigger 12 is pulled and a second power-on signal is output, causing the motor 50 to start driving. Between time t12 and time t13, the amount of trigger pulling increases, and the rotation speed of the motor 50 increases as the trigger pulling amount increases. Between time t13 and time t14, the amount of trigger pulling is maintained at the maximum amount, and the rotation speed of the motor 50 is maintained at the maximum speed. Between time t14 and time t15, the amount of trigger pulling decreases, and the rotation speed of the motor 50 decreases as the trigger pulling amount decreases. At time t15, the trigger 12 is turned off, and a second power-off signal is output.

[0075] <1-3.Effects> According to the first embodiment described above in detail, the following effects are achieved. (1) When the soft no-load is enabled and before a load is detected, the user can manually change the rotation speed based on the first map until the rotation speed reaches a predetermined speed. Furthermore, when the soft no-load is enabled and the soft no-load is being executed, the user can manually adjust the rotation speed in the low-speed range to perform operations such as positioning the electric work machine relative to the work target. Furthermore, when the soft no-load is disabled, the user can manually change the rotation speed based on the second map regardless of whether a load is detected. Furthermore, since the correspondence relationships of the second map when the dial position is "1" to "4" are different from the correspondence relationships of the first map, the user can intuitively distinguish between the enabled and disabled states of the soft no-load.

[0076] (2) When the soft no-load function is disabled, the command value is calculated based on the corresponding relationship in the second map according to the set target value. Therefore, when the soft no-load function is disabled, the rotation speed can be manually adjusted for each target value.

[0077] (3) When the soft no-load function is enabled and after the load is detected, the command value is calculated based on the same correspondence relationship regardless of the set target value. Therefore, when the soft no-load function is enabled, the user can manually change the rotation speed at the same rate of change regardless of the set target value. In other words, when the soft no-load function is enabled, the burden on the user to adjust the rotation speed is reduced, improving workability.

[0078] (4) Once a load is detected, even if the load is no longer detected, the motor 50 can be rotated based on the command value calculated using the first map. Therefore, even if the load temporarily decreases during work, a decrease in the rotation speed can be suppressed.

[0079] 2. Second Embodiment <2-1. Differences from the first embodiment> The second embodiment has a basic configuration similar to that of the first embodiment, and therefore differences will be described below. Note that the same reference numerals as those in the first embodiment indicate the same configuration, and the preceding description will be referred to.

[0080] In the first embodiment described above, when the soft no-load is enabled and the soft no-load is released, the speed command calculation unit 310 uses the first map to calculate the rotation speed command value according to the pull amount of the trigger 12. In contrast, in the second embodiment, the speed command calculation unit 310 differs from the first embodiment in that when the soft no-load is enabled and the soft no-load is released, the speed command calculation unit 310 sets the rotation speed target value set via the speed adjustment dial 14 as the command value.

[0081] A graph showing the rotation speed command value versus the trigger pull amount when the soft no-load function according to this embodiment is enabled is shown in Fig. 7. Also, a graph showing the rotation speed command value versus the trigger pull amount when the soft no-load function according to this embodiment is disabled is shown in Fig. 8.

[0082] The soft no-load speed is set to a value between a target value corresponding to the dial position "1" and a target value corresponding to the dial position "2". As shown in FIG. 7, when the soft no-load is enabled, if the dial position is "1", the command value increases to the target value according to the trigger pull amount. When the soft no-load is enabled, if the dial position is "2" to "5", the command value increases to the soft no-load speed according to the trigger pull amount, and when the soft no-load is released, each target value is set to the command value. Then, even if the load acting on the motor 50 is no longer detected after the soft no-load is released, the target value is set to the command value.

[0083] Therefore, when the soft no-load function is enabled, if the dial position is between "2" and "5", the speed change range according to the trigger pull amount corresponds to the low speed range up to the soft no-load speed. On the other hand, as shown in FIG. 8, when the soft no-load function is disabled, the speed change range according to the trigger pull amount corresponds to all speed ranges up to each target value.

[0084] <2-2.Effects> According to the second embodiment described above in detail, in addition to the effects (1) and (2) of the first embodiment described above, the following effect is also achieved.

[0085] (5) When the soft no-load function is enabled and a load is detected, the target speed is automatically set to the command value regardless of the trigger pull amount. Therefore, when the soft no-load function is enabled and a load is detected, the user can work with the electric work machine 10 without adjusting the rotation speed.

[0086] (6) Once a load is detected, the motor 50 can be rotated based on the target value even if the load is no longer detected. Therefore, even if the load temporarily decreases during work, a decrease in the rotation speed can be suppressed.

[0087] 3. Other Embodiments Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be implemented in various modified forms.

[0088] (a) In the above embodiment, the first map and the second map may be stored in a memory other than the ROM 30b built into the microcomputer 30. For example, the first map and the second map may be stored in an external hard disk or removable media that is configured to be connectable to the microcomputer 30.

[0089] (b) The electric work machine 10 is not limited to a jigsaw. The electric work machine 10 may be any electric work machine that is equipped with a trigger. For example, the electric work machine 10 may be an electric tool such as a reciprocating saw, a hammer drill, or a chain saw, or may be a gardening tool such as a grass cutter.

[0090] (c) Multiple functions possessed by one component in the above embodiments may be realized by multiple components, or one function possessed by one component may be realized by multiple components. Also, multiple functions possessed by multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Also, part of the configuration of the above embodiments may be omitted. Also, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0091] (d) In addition to the electric working machine described above, the present disclosure can also be realized in various forms, such as a system including the electric working machine as a component, a program for operating the microcomputer 30, a non-transient physical recording medium such as a semiconductor memory on which this program is recorded, and a motor driving method. [Explanation of symbols]

[0092] 10...electric work machine, 12...trigger, 13...main power switch, 14...speed adjustment dial, 20...battery pack, 30...microcomputer, 30a...CPU, 30b...ROM, 30c...RAM.

Claims

1. A motor; An operation unit for driving the motor; A setting unit for setting a target value of the rotation speed of the motor; A control unit configured to control the rotation speed in response to an operation of the operation unit, The control unit is switching between enabling and disabling a specific mode for increasing the rotational speed of the motor when a load on the motor is detected based on receipt of a predetermined signal; Detecting a load on the motor; When the specific mode is enabled, before the load is detected, the rotation speed is controlled to a first rotation speed having a predetermined speed as an upper limit and based on a first correspondence relationship and an operation amount of the operation unit, the first correspondence relationship correlating the operation amount of the operation unit with the rotation speed and being constant regardless of the target value; When the specific mode is disabled, the rotation speed is controlled to a second rotation speed based on a second correspondence relationship and an operation amount of the operation unit, the second correspondence relationship associates the operation amount of the operation unit with the rotation speed, and the first rotation speed and the second rotation speed corresponding to the same operation amount of the operation unit are different from each other; and when the specific mode is enabled, after the load is detected, the rotation speed is controlled to a third rotation speed based on the first correspondence relationship and the operation amount of the operation unit, with the target value as an upper limit. Electric work equipment.

2. The method further includes a storage unit in which the first correspondence relationship and the second correspondence relationship are stored. The electric operating machine according to claim 1.

3. The predetermined speed corresponds to the lower of the target value set via the setting unit and a pre-set no-load speed, the second correspondence relationship includes a plurality of third correspondence relationships that differ for each of the target values, the second rotation speed has an upper limit of the target value, and is based on one of the plurality of third correspondence relationships corresponding to the target value set via the setting unit and an operation amount of the operation unit.

3. The electric operating machine according to claim 1 or 2.

4. The control unit is and when the specific mode is enabled, in response to the load being no longer detected after the load is detected, continuing to control the rotation speed to the third rotation speed. The electric operating machine according to any one of claims 1 to 3.

5. A motor, An operation unit for driving the motor; A setting unit for setting a target value of the rotation speed of the motor; A control unit configured to control the rotation speed in response to an operation of the operation unit, The control unit is switching between enabling and disabling a specific mode for increasing the rotational speed of the motor when a load on the motor is detected based on receipt of a predetermined signal; Detecting a load on the motor; When the specific mode is enabled, before the load is detected, the rotation speed is controlled to a first rotation speed that is an upper limit of a predetermined speed and is based on a first correspondence relationship and an operation amount of the operation unit, the first correspondence relationship correlating the operation amount of the operation unit with the rotation speed; When the specific mode is disabled, the rotation speed is controlled to a second rotation speed based on a second correspondence relationship and an operation amount of the operation unit, the second correspondence relationship associates the operation amount of the operation unit with the rotation speed, and the first rotation speed and the second rotation speed corresponding to the same operation amount of the operation unit are different from each other; When the specific mode is enabled, after the load is detected, the rotation speed is controlled to the target value set via the setting unit, and when the load is no longer detected after the load is detected, the rotation speed is continued to be controlled to the target value. Electric work equipment.

6. An electric work machine, A motor configured to drive a tool attached to the electric working machine; a drive switch that is operated within a first operation amount range or a second operation amount range that is a range of an operation amount larger than the first operation amount range in order to drive the motor; a setting unit for enabling or disabling a specific function of increasing a rotation speed of the motor in response to detection of a load on the motor; A control unit that controls the driving of the motor, The control unit is when the specific function is disabled, changing the rotation speed in response to an operation amount of the drive switch that is within the first operation amount range or the second operation amount range, regardless of a load on the motor; When the specific function is enabled, before a load on the motor is detected, the rotation speed is changed according to the operation amount of the drive switch based on the operation amount of the drive switch being within the first operation amount range, and the rotation speed is maintained at a constant value based on the operation amount of the drive switch being within the second operation amount range. Furthermore, the rotation speed when the operation amount of the drive switch is a predetermined operation amount within the range of the first operation amount when the specific function is enabled is made different from the rotation speed when the operation amount of the drive switch is the predetermined operation amount when the specific function is disabled. Electric work equipment.

Images