JP2022157786A - work machine - Google Patents

Abstract

To provide a work machine with good workability.SOLUTION: In a silent mode, a calculation part 40 executes a first control for limiting the number of rotations of a motor 9 to a specified value or less to control the duty so that the number of rotations of a circular saw blade becomes a prescribed number of rotations, when a load is less than a control changeover threshold, and executes a second control for maximizing the duty when the load is the control changeover threshold or more. The calculation part 40 has a function of learning a user's use mode of a circular saw and changing the control changeover threshold. The calculation part 40 lowers the control changeover threshold when a load in one work period exceeds a reference value, and raises the control changeover threshold when the load becomes less than the reference value.SELECTED DRAWING: Figure 8

Description

The present invention relates to a working machine such as a circular saw.

Patent Literature 1 listed below discloses a work machine that changes the control state depending on the load.

JP 2015-037822 A

Controlling a work machine by a microcomputer or the like can improve workability, but the content of control may not be optimal for the worker. For example, the automatic change of the control state as described in the above document improves workability, but depending on the operator, the timing of changing the control state may be early or late, so there is room for improvement. was there. Also, when controlling the number of rotations of the motor, there are cases in which the startup from start-up and how to reduce the number of rotations during braking may not be optimal for the operator. If such control details do not suit the operator, it is conceivable to provide an input unit (panel, setting button, etc.) that can change the control details, but the increase in the number of parts increases the cost, and it takes time and effort to make adjustments. There is a problem that it takes

The present invention has been made in recognition of such circumstances, and an object thereof is to provide a work machine with good workability.

One aspect of the present invention is a working machine. This work machine
a motor;
a control unit that controls driving of the motor;
a rotary tool rotated by the motor;
a switch for switching between driving and stopping the motor,
The control parameters are changed based on the operator's operation.
According to this aspect, the aspect of control change can be adjusted according to the tendency of the operator.

The operation may include any one of a method of pressing the work machine, an operation on the switch, and a time during which the motor is in a driving state.

The parameter may include any one of a condition for switching between different control states and an amount of change in the number of revolutions during a predetermined period of time.

The control unit has a first control in which the rotation speed of the motor is limited to a predetermined value or less, and a second control in which the motor can be driven at a rotation speed exceeding the predetermined value,
The first control and the second control are configured to switch depending on whether the load exceeds or falls below the control switching threshold,
The parameter may include the control switching threshold.

The control switching threshold may be lowered when the load exceeds a reference value. The control switching threshold may be increased when the load falls below the reference value. According to this, the control switching threshold can be appropriately changed.

The control unit has a soft start function that gradually increases the rotation speed of the motor toward a target value after the motor starts driving,
The parameter may include a slope of the motor speed-up in the soft start function.

The slope may be steepened when the time from when the switch becomes a state of instructing the drive of the motor to when the load is applied to the motor falls below a reference value.

The gradient may be made gentle when the time from when the switch starts driving the motor to when the load is applied to the motor exceeds a reference value.

A winding switching unit for switching the winding form of the motor between a high-rotation winding and a high-torque winding,
the winding configuration is configured to switch when the load exceeds or falls below a winding switching threshold;
The parameters may include the winding switching threshold.

The winding switching threshold may be lowered when the time from start to stop of the motor exceeds a reference value.

The winding switching threshold may be increased when the time from start to stop of the motor is below a reference value.

Said parameter may be varied within a predetermined range. According to this, excessive parameter adjustment can be suppressed.

Any combination of the above constituent elements, and conversion of expressions of the present invention between methods and systems are also effective as embodiments of the present invention.

ADVANTAGE OF THE INVENTION According to this invention, a working machine with good workability can be provided.

1 is a plan view of a circular saw according to an embodiment of the present invention; FIG. The same side view. The same rear view. Same front view. 1 is a first plan view, partly in section, of the circular saw; FIG. The second plan view of the same. AA sectional view of FIG. FIG. 2 is a circuit block diagram of the circular saw; There is a graph showing the relationship between the load and the motor speed in the power mode and the silent mode of the circular saw. In the silent mode, the control switching thresholds for switching from constant speed control to constant duty control are shown at the highest and lowest. graph. 4 is a graph showing the relationship between time and motor rotation speed in the slow start control of the circular saw, showing cases where the gradient of the motor rotation speed rise is maximum, intermediate, and minimum. 3 is a graph showing the relationship between the load and the number of revolutions of the motor in the circular saw, and the graph showing the highest and lowest winding switching thresholds for switching from the high-rotation winding to the high-torque winding. 4 is a control flowchart for changing a control switching threshold in the circular saw; FIG. 4 is a control flow chart for changing the gradient of the increase in motor rotation speed in the circular saw; FIG. FIG. 4 is a control flowchart for changing a winding switching threshold in the circular saw; FIG.

Hereinafter, the same or equivalent constituent elements, members, etc. shown in each drawing are denoted by the same reference numerals, and duplication of description will be omitted as appropriate. The embodiments are illustrative rather than limiting of the invention. All features and combinations thereof described in the embodiments are not necessarily essential to the invention.

The present embodiment relates to a working machine, and more specifically to a circular saw (cordless circular saw). This circular saw comprises a base 1 and a body 2. - 特許庁The base 1 is a substantially rectangular plate made of metal such as aluminum. The longitudinal direction of the base 1 is parallel to the cutting direction (front-rear direction). The bottom surface of the base 1 is a sliding surface with the work material.

The main body 2 is connected to the base 1 at two front and rear positions as will be described later, and is rotatable and tiltable to the left and right with respect to the base 1 . The main body 2 includes a motor housing 3, a handle portion 4, a gear cover 5, a saw cover 6, a protective cover 7, and a circular saw blade 8 (rotary tool).

The motor housing 3 is made of resin, for example, and incorporates a motor 9 (electric motor) shown in FIGS. A motor 9 rotates the circular saw blade 8 . The handle portion 4 is made of the same material as the motor housing 3 and extends in the front-rear direction above the motor housing 3 . The handle portion 4 is provided with a main trigger switch 18 (main switch) as an operating portion (switch) for the operator to switch between driving and stopping the motor 9 .

As shown in FIGS. 3 and 4, the handle portion 4 is composed of a left part provided integrally with the motor housing 3 and a right part sandwiched between the motor housing 3 and the gear cover 5. A battery pack mounting portion 4a, which will be described later, is formed by a combination of the component and the right side component, and a control circuit board housing portion 4b, which will be described later, is provided in the right side component of the handle portion 4 located on the circular saw blade 8 side. The boundary between the left side part and the right side part of the handle portion 4 is a line appearing in the center of the handle portion 4 in FIGS. 1, 3, 4 and the like.

A battery pack attachment portion 4a (battery attachment portion) and a control circuit board storage portion 4b are provided integrally at the lower rear end portion of the handle portion 4 . A battery pack 20 (storage battery) is detachably attached to the battery pack attachment portion 4a by sliding it from the rear. A mode changeover switch 16 (for example, a tact switch) and an LED 29 as a display for displaying a mode are provided on the upper surface of the battery pack mounting portion 4a below the handle portion 4. FIG.

The operator can select either a power mode (normal mode) or a silent mode (eco mode) with the mode changeover switch 16 . The mode changeover switch 16 and the LED 29 are provided on the same substrate, and when the silent mode is set by operating the mode changeover switch 16, the LED 29 lights up. The mode changeover switch 16 is provided on the lower side of the handle portion 4 to prevent the mode changeover switch 16 from colliding with something and suddenly switching the mode.

The battery pack 20 supplies drive power to the motor 9 . As shown in FIG. 1, the left side surface of the battery pack 20 attached to the battery pack mounting portion 4a and the left side surface of the motor housing 3 are substantially on the same plane. That is, the distance from the circular saw blade 8 to the left side surface of the motor housing 3 and the distance from the circular saw blade 8 to the left side surface of the battery pack 20 are substantially the same. The circular saw can be placed downward, and the replacement work of the circular saw blade 8 can be easily performed.

The control circuit board housing portion 4 b is provided on the right side of the battery pack 20 . The control circuit board 21 is housed and held in the control circuit board housing portion 4b. The control circuit board 21 is equipped with a control section (controller) that controls the operation of the motor 9 . The control circuit board 21 is substantially perpendicular to the rotation axis of the motor 9 (the rotation axis of the circular saw blade 8). The left side of the control circuit board 21, that is, the space between the control circuit board 21 and the battery pack 20 is partitioned by a resin controller cover 22, for example.

The gear cover 5 is provided on the right side of the handle portion 4 . The gear cover 5 is made of metal, for example, and incorporates a rotation transmission mechanism between the motor 9 and the circular saw blade 8 . The rotation transmission mechanism consists of a well-known speed reduction mechanism or the like. The saw cover 6 is attached to the gear cover 5 and covers the upper half of the circular saw blade 8 together with the gear cover 5 . The saw cover 6 may be made of the same material as the gear cover 5 and may be integrally formed. The front end portions of the gear cover 5 and the saw cover 6 are connected to the rotation support portion 14 .

The protective cover 7 is made of resin, for example, and is rotatably provided on the rear side of the gear cover 5 along the outer edges of the gear cover 5 and the saw cover 6 . A spring (not shown) is interposed between the gear cover 5 and the protective cover 7 . The spring biases the protective cover 7 against the gear cover 5 in the circumferential direction of the gear cover 5 and the saw cover 6 and in the direction of covering the lower half of the circular saw blade 8 (counterclockwise in FIG. 2). Therefore, when the cutting operation is not performed, the protective cover 7 covers the lower half of the circular saw blade 8 (the portion protruding downward from the bottom surface of the base 1) except for the front part.

A bevel plate 12 is erected on the front portion of the base 1 . The bevel plate 12 stands upright in the lateral direction substantially orthogonal to the cutting direction. A long hole 13 is provided in the bevel plate 12 . The long hole 13 has an arc shape centered on the first tilting shaft portion 15a extending in the cutting direction and perpendicular to the first tilting shaft portion 15a. The rotation support portion 14 is supported so as to be tiltable to the left and right with respect to the base 1 around the first tilting shaft portion 15a. The tilting position of the rotation support portion 14 is adjusted with the tilt angle adjusting lever 11 loosened, and fixed by tightening the tilt angle adjusting lever 11 . The rotary support portion 14 rotatably supports the front end portion of the saw cover 6 with a shaft parallel to the rotary shaft of the motor 9 (the rotary shaft of the circular saw blade 8). Adjustment and fixing of the rotation position of the saw cover 6 will be described later.

A link 10 is provided on the rear portion of the base 1 so as to be rotatable about a tilting shaft portion 15b coaxial with the first tilting shaft portion 15a, along the left side surface of the gear cover 5. As shown in FIG. The link 10 is made of metal such as aluminum. When the cutting depth adjusting lever 19 is loosened, the link 10 and the gear cover 5 are slidable relative to each other, and the rotational position of the saw cover 6 with respect to the base 1, that is, the cutting depth can be adjusted. By tightening the cutting depth adjusting lever 19, the rotational position of the gear cover 5 can be fixed.

As shown in FIG. 6, the motor 9 is an inner rotor type brushless motor having a rotor core 9b around an output shaft 9a. The output shaft 9a is parallel to the rotation axis of the circular saw blade 8. As shown in FIG. The rotor core 9b rotates integrally with the output shaft 9a. A rotor magnet 9c is inserted and supported in the rotor core 9b. The stator core 9d is provided so as to surround the outer peripheral surface of the rotor core 9b. A stator coil 9f is provided on the stator core 9d with an insulator 9e interposed therebetween. A switching board 23 is fixed to the left end side of the stator core 9d. The switching board 23 is substantially perpendicular to the output shaft 9a.

As shown in FIG. 7, six switching elements 23a (such as FETs) are mounted on the switching board 23 with the main body section laid down. The switching element 23 a switches the supply voltage from the battery pack 20 . As shown in FIG. 5 , terminal portion 20 a of battery pack 20 and switching board 23 are electrically connected to each other by wiring 24 . Wiring 25 electrically connects terminal portion 20 a of battery pack 20 and control circuit board 21 to each other. The wiring 26 electrically connects the control circuit board 21 and the switching board 23 to each other. A control signal from the controller of the control circuit board 21 is applied to the control terminal (gate) of the switching element 23a on the switching board 23 through the wiring 26 to control the on/off of the switching element 23a. A cooling fan 33 is attached to the output shaft 9a of the motor 9 and rotates together with the output shaft 9a. The airflow generated by the cooling fan 33 cools the motor 9 and the switching element 23a.

FIG. 8 is a circuit block diagram of the circular saw according to the embodiment. A detection resistor Rs is provided in the current path of the motor 9 . The rotation sensor 34 is a magnetic sensor such as three Hall elements arranged near the motor 9 . The inverter circuit 28 is composed of three-phase bridge-connected switching elements Q1 to Q6 (corresponding to the switching element 23a shown in FIGS. 6 and 7).

The switching circuit driving unit 35 is a circuit for switching the ON/OFF state (electrically connected or disconnected state) of the winding form switching switches 35 a and 35 b , and is controlled by the arithmetic unit 40 . The winding form switching switches 35a and 35b are switches (for example, relays or switching elements) connected to the stator coils 9f of the respective phases of the motor 9, and constitute a winding switching section. The winding configuration switching switches 35a and 35b are in such a relationship that when one is on, the other is off. The winding configuration of the stator coil 9f is Y connection (star connection) when the winding configuration switching switch 35a is on, and delta connection when the winding configuration switching switch 35b is on.

The control section 27 includes a current detection circuit 36 , a voltage detection circuit 37 , an inverter drive section 38 , a rotor position detection circuit 39 and a calculation section 40 . The controller 27 is mounted on the control circuit board 21 shown in FIG. The current detection circuit 36 detects the current (motor current) flowing through the motor 9 by the voltage of the detection resistor Rs, that is, the load, and transmits the detected load to the calculation unit 40 . The load may be detected not only by current but also by voltage or duty, change in rotation speed of motor 9, or a combination thereof. In the following explanation, it is assumed that the load is detected by the motor current. The voltage detection circuit 37 detects the output voltage of the battery pack 20 and transmits it to the calculation unit 40 . The inverter driving section 38 controls ON/OFF of the switching elements Q1 to Q6 of the inverter circuit 28 (PWM control) under the control of the computing section 40 . A rotor position detection circuit 39 detects the number of revolutions of the motor 9 based on the output signal of the rotation sensor 34 and transmits it to the calculation unit 40 .

When the main trigger switch 18 is turned on, the calculation unit 40 outputs a PWM signal to each switching element 23a of the inverter circuit 28 according to the mode (for example, power mode or silent mode) set by the mode switch 16. applied to control the driving of the motor 9.

In the power mode, the calculation unit 40 sets the duty (hereinafter simply referred to as “duty”) of the PWM signal applied to each switching element 23a to the maximum (for example, 100%) regardless of the load. In the silent mode, when the load is less than the control switching threshold, the calculation unit 40 performs the first control for controlling the duty so that the number of rotations of the circular saw blade 8 becomes a predetermined number of rotations (for example, 3,000 rotations/minute). , and when the load is equal to or higher than the control switching threshold, the second control that maximizes the duty is performed as in the power mode. In the first control, the number of revolutions of the motor 9 is limited to a predetermined value or less. In the second control, the motor 9 can be driven at a rotational speed exceeding the predetermined value. The control switching threshold is an example of a control parameter. As will be described later with reference to FIG. 12, the calculation unit 40 has a function of learning how the operator uses the circular saw and changing the control switching threshold (control switching current).

When the main trigger switch 18 is turned on (when the main trigger switch 18 supports the driving of the motor 9) to start the motor 9, the calculation unit 40 gradually Slow start control (soft start control) is performed by increasing the duty to gradually increase the rotation speed of the motor 9 toward the target value. The slope of the increase in the motor rotation speed (the amount of change in the rotation speed per predetermined time, the rate of change in the rotation speed) in the slow start control is an example of a control parameter. As will be described later with reference to FIG. 13, the calculation unit 40 has a function of learning how the operator uses the circular saw and changing the gradient of the motor rotation speed increase in the slow start control.

The calculation unit 40 sets the winding form (connection method) of the stator coil 9f to a high-rotation winding when the load is less than the winding switching threshold, and to a high-torque winding when the load exceeds the winding switching threshold. It has a winding switching function. The high rotation windings are now wye-connected (star-connected) and the high-torque windings are now delta-connected. The winding switching threshold is an example of a control parameter. The calculation unit 40 has a function of learning how the operator uses the circular saw and changing the winding switching threshold value (winding switching current).

FIG. 9 is a graph showing the relationship between the load and the motor speed in the power mode and silent mode of the circular saw according to the embodiment. The silent mode shows the highest and lowest control switching thresholds for shifting from the first control (constant rotation speed control) to the second control (constant duty control). The calculation unit 40 changes the control switching threshold according to the force (pressing force) with which the operator presses the circular saw against the work material. Specifically, the calculation unit 40 lowers the control switching threshold as the pressing force increases as a work tendency. As a result, in the case of a worker who tends to work with a high load, the control switching threshold becomes lower than in the case of a worker who tends to work with a low load, and the first control is switched to the second control at a lower load. Become. Therefore, the work speed is increased for workers who tend to work under heavy loads. For workers who tend to work with low loads, the noise reduction effect is enhanced. A pressing force is an example of an operator's operation.

FIG. 10 is a graph showing the relationship between time and motor rotation speed in the slow start control of the circular saw according to the embodiment. The slope of the motor rotation speed increase shows the highest, middle, and lowest cases. The calculation unit 40 changes the slope of the motor rotation speed increase in the slow start control according to the time from when the main trigger switch 18 is turned on until the load is applied. Specifically, the calculation unit 40 increases (steepens) the gradient of the increase in motor rotation speed as the time from turning on the main trigger switch 18 to applying a load is shorter as a work tendency. As a result, in the case of an operator who takes a short time from when the main trigger switch 18 is pulled to when the circular saw starts to be pressed against the work material, the slope of the increase in motor rotation speed is higher than that of an operator who takes a long time. increases, and the circular saw blade 8 and the motor 9 reach the target rotation speed in a shorter time. Therefore, for a worker who has a short time between pulling the main trigger switch 18 and starting to press the circular saw against the work material, the worker can start working immediately after pulling the main trigger switch 18, increasing the work speed. . For the operator who spends a long time, the effect of reducing the reaction by the slow start control is enhanced, and the circular saw blade 8 can be easily adjusted to the cutting position. The time is an example of an operator's operation.

The time from when the main trigger switch 18 is turned on until the load is applied is determined by the time from when the motor 9 starts and reaches the maximum rotation speed (target rotation speed) to when the load current is detected.
(Example of judgment formula for judging that it is short)
The time from when the main trigger switch 18 is turned on until the load current is detected - the time when the motor starts and reaches the maximum rotation speed < reference value (an example of a judgment formula for judging that it is long)
The time from when the main trigger switch 18 is turned on until the load current is detected - The time when the motor starts up and reaches the maximum rotation speed ≥ reference value

FIG. 11 is a graph showing the relationship between the load and the number of revolutions of the motor in the circular saw according to the embodiment. The winding switching thresholds for switching the winding configuration (hereinafter simply referred to as "winding configuration") of the stator coil 9f from the high-rotation winding to the high-torque winding show the highest and lowest values. The calculation unit 40 changes the winding switching threshold according to the time from when the main trigger switch 18 is turned on until it is turned off, ie, the activation time of the motor 9 per work. Specifically, the calculation unit 40 lowers the winding switching threshold as the work tendency of the motor 9 increases as the start-up time of the motor 9 per work increases. As a result, a worker who spends a long time on one task has a lower winding switching threshold than a worker who spends a short time on one task. It will switch to line. Therefore, a worker who spends a long time on one task can efficiently use the capacity of the battery pack 20, and a worker who spends a short time on one task can improve work efficiency. The startup time of the motor 9 per work is an example of operator's operation.

FIG. 12 is a control flowchart for changing the control switching threshold in the circular saw according to the embodiment. When the main trigger switch 18 is turned on (YES in S1), if the silent mode is not set (NO in S2), the arithmetic unit 40 drives the motor 9 under constant duty control (S3). The computing unit 40 records (stores) the maximum value of the current (maximum current) supplied to the motor 9, that is, the maximum load (S4). When the main trigger switch 18 is turned off (YES in S5), the calculation section 40 stops the motor 9 (S13).

In the case of the silent mode in S2 (YES in S2), the calculation unit 40 drives the motor 9 under the first control (constant rotation speed control) (S6). If the load, that is, the motor current is not equal to or greater than the control switching threshold (NO in S7), the calculation unit 40 continues the first control (constant rotation speed control). The motor 9 is stopped (S13).

When the load, that is, the motor current becomes equal to or greater than the control switching threshold during execution of the first control (constant rotation speed control) (YES in S7), the calculation unit 40 drives the motor 9 under the second control (constant duty control) ( S9). The calculation unit 40 records (stores) the maximum value (maximum current) of the current supplied to the motor 9 during execution of the second control (constant duty control), that is, the maximum load (NO in S10, S11). When the load, that is, the motor current becomes less than the control switching threshold (YES in S10), the calculation unit 40 shifts to the first control (constant rotation speed control). When the main trigger switch 18 is turned off (YES in S12), the calculation section 40 stops the motor 9 (S13).

After stopping the motor 9 (S13), if the maximum current recorded in S4 or S12 exceeds the reference current I1 (reference value) as the first reference value (YES in S14), the calculation unit 40 switches the control. The threshold (control switching current) is lowered (S15). If the maximum current is less than the reference current I2 (I2≦I1) as the second reference value (NO in S14, YES in S16), the calculation unit 40 increases the control switching threshold (control switching current) (S17). The calculation unit 40 does not change the control switching threshold (control switching current) when the maximum current is in the range of I2 or more and I1 or less. The calculation unit 40 returns to S1.

FIG. 13 is a control flow chart for changing the slope of the increase in motor rotation speed in the circular saw according to the embodiment. When the main trigger switch 18 is turned on (YES in S21), the calculation unit 40 starts the motor 9 by slow start control (S22). If there is no record of the time until the load is applied after the main trigger switch 18 is turned on this time (YES in S23), the calculation unit 40 stores the time until the load is applied when the load is detected (YES in S24). (S25). When the main trigger switch 18 is turned off (YES in S26), the calculation section 40 stops the motor 9 (S27).

If the time from the stop of the motor 9 (S27) until the load is applied stored in S25 exceeds the reference time T1 as the first reference value (YES in S28), the calculation unit 40 The duty increase rate (increase speed) is decreased (the slope of the motor rotation speed increase in the slow start control is moderated) (S29). When the time until the load is applied is less than the reference time T2 (T2≦T1) as the second reference value (NO in S28, YES in S31), the calculation unit 40 calculates the duty increase rate (increase speed) in the slow start control. (increase the gradient of motor speed increase in slow start control) (S32). The calculation unit 40 does not change the duty increase rate in the slow start control when the time until the load is applied is in the range of T2 to T1. The calculation unit 40 erases the time until the load is applied (S30), and returns to S21.

FIG. 14 is a control flowchart for changing the winding switching threshold in the circular saw according to the embodiment. When the main trigger switch 18 is turned on (YES in S41), the calculation unit 40 drives the motor 9 by winding the winding at high rotation speed (S42). If the load, that is, the motor current is less than the winding switching threshold (NO in S43), the calculation unit 40 drives the motor 9 while maintaining the winding configuration as a high-rotation winding, and if the main trigger switch 18 is turned off, (YES in S44), the motor 9 is stopped (S48).

When the load, that is, the motor current exceeds the winding switching threshold (YES in S43) while the winding configuration is the high-rotation winding, the computing unit 40 switches the winding configuration to the high-torque winding to drive the motor 9. (S45). If the load, that is, the motor current is not less than the winding switching threshold (NO in S46), the computing unit 40 drives the motor 9 while maintaining the winding configuration as the high-torque winding. (NO in S46), the motor 9 is stopped (S48). When the load, that is, the motor current becomes less than the winding switching (YES in S46) while the winding configuration is the high-torque winding, the computing unit 40 switches the winding configuration to the high-rotation winding to drive the motor 9 ( S42).

After the motor 9 is stopped (S48), if the time from when the main trigger switch 18 is turned on until it is turned off again, that is, when the start-up time of the motor 9 exceeds the reference time Ta as the first reference value (S49 YES), the winding switching threshold (winding switching current) is lowered (S50). If the startup time is shorter than the reference time Tb (Tb≦Ta) as the second reference value (NO in S49, YES in S51), the calculation unit 40 increases the winding switching threshold (winding switching current) (S52 ). The calculation unit 40 does not change the winding switching threshold (winding switching current) when the activation time is in the range of Tb to Ta. The calculation unit 40 returns to S41.

According to this embodiment, the following effects can be obtained.

(1) The computing unit 40 changes parameters for controlling the motor 9 based on the operator's operation. For this reason, unlike the case where the control parameters are fixed, the control parameters are changed according to the work tendency of each worker as it is used, making it a circular saw (work machine) that is easy to use for each worker. and workability is improved. In particular, the calculation unit 40 is not based on the information due to the material to be processed, the battery capacity, etc., but rather the operator's operation during the work, specifically, how to press (how to apply a load), how to operate the trigger switch 18, etc. Since the control parameters are changed based on information that varies greatly depending on the operator, it is possible to realize a working machine that is easy for the operator to use. For example, in the case of technology that determines the material of the workpiece by measuring the current and automatically selects the control details accordingly, the optimal control for the workpiece is executed, but the details of control can be changed by the operator. However, the present invention can solve the problem of the present application.

(2) The computing unit 40 determines a control switching threshold when the main trigger switch 18 is turned on next time according to the load in one work period from when the main trigger switch 18 is turned on until it is turned off. change. Specifically, the calculation unit 40 decreases the control switching threshold when the load in one work period exceeds the reference value, and increases the control switching threshold when the load falls below the reference value. As a result, a worker who tends to work with a high load can work faster, and a worker who tends to work with a lower load can achieve a higher noise reduction effect. That is, the circular saw (working machine) is easy for each operator to use, and workability is improved. Alternatively, the average value of the maximum load in a plurality of work periods may be calculated and the average value may be compared with a reference value to change the control switching threshold.

(3) The calculation unit 40 calculates the slope of the motor speed increase in the slow start control when the main trigger switch 18 is next turned on, according to the time from when the main trigger switch 18 is turned on until the load is applied. change. Specifically, if the time from when the main trigger switch 18 is turned on to when the load is applied falls below a reference value, the calculation unit 40 increases the gradient of the motor rotation speed increase, and if the time exceeds the reference value, the motor speed increases. Make the gradient of the rotation speed increase gentler. As a result, for a worker who has a short time from when the main trigger switch 18 is pulled until the circular saw starts to be pressed against the work material, the work can be performed immediately after the main trigger switch 18 is pulled, increasing the work speed. For the operator who spends a long time, the effect of reducing the reaction by the slow start control is enhanced, and the circular saw blade 8 can be easily adjusted to the cutting position. That is, the circular saw (working machine) is easy for each operator to use, and workability is improved. In addition, the average value of the time from when the main trigger switch 18 is turned on until the load is applied is calculated for multiple times, and the average value is compared with the reference value to change the slope of the motor rotation speed increase in the slow start control. may

(4) The calculation unit 40 changes the winding switching threshold when the main trigger switch 18 is turned on next time according to the activation time of the motor 9 per work. Specifically, the computing unit 40 lowers the winding switching threshold when the starting time of the motor 9 per work exceeds the reference value, and reduces the winding switching threshold when the starting time of the motor 9 per work falls below the reference value. Increase the switching threshold. As a result, a worker who spends a long time on one task can efficiently use the capacity of the battery pack 20, and a worker who does a short time on one task can improve work efficiency. That is, the circular saw (working machine) is easy for each operator to use, and workability is improved. Alternatively, the winding switching threshold may be changed by calculating the average value of the starting times of the motor 9 in a plurality of operations and comparing the average value with a reference value.

Although the present invention has been described above with reference to the embodiments, 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. By the way. Modifications will be discussed below.

The working machine of the present invention is not limited to circular saws, and may be of other types. The work machine of the present invention is not limited to a cordless type that operates on power from a battery pack, and may be a corded type that operates on power from an external AC power supply. In addition, it is sufficient if the control content is changed by judging the worker's work tendency (whether accuracy is prioritized or time is prioritized, etc.) by the operator's operation (trigger switch operation, load application method, etc.). Control other than the above is also applicable, such as gradually stopping the motor by weakening the braking force of the brake control executed when the trigger switch is turned off when the trigger switch is carefully operated.

DESCRIPTION OF SYMBOLS 1... Base 2... Main body 3... Motor housing 4... Handle part 4a... Battery pack attachment part 4b... Control circuit board storage part 5... Gear cover 6... Saw cover 7... Protective cover 8... Circular saw Blade 9 Brushless motor 9a Output shaft 9b Rotor core 9c Rotor magnet 9d Stator core 9e Insulator 9f Stator coil 10 Link 11 Tilt angle adjustment lever 12 Bevel plate DESCRIPTION OF SYMBOLS 13... Long hole 14... Rotating support part 15a... Tilting shaft part 15b... Tilting shaft part 16... Mode changeover switch 18... Main trigger switch 19... Cutting depth adjustment lever 20... Battery pack 20a Terminal part 21 Control circuit board 22 Controller cover 23 Switching board 23a Switching element 24 to 26 Wiring 27 Control part 28 Inverter circuit 29 LED 33 Cooling fan 34... Rotation sensor 35... Switching circuit drive unit 35a, 35b... Winding form switching switch (winding switching unit) 36... Current detection circuit 37... Voltage detection circuit 38... Inverter drive unit 39... Rotation child position detection circuit, 40... calculation unit, Rs... detection resistor.

Claims (13)

a motor;
a control unit that controls driving of the motor;
a rotary tool rotated by the motor;
a switch for switching between driving and stopping the motor,
A work machine that changes control parameters based on the operator's operation. 2. The working machine according to claim 1, wherein said operation includes any one of how to press against the working machine, operation on said switch, and time during which said motor is in a driving state. The working machine according to claim 1 or 2, wherein the parameter includes any one of a condition for switching between different control states and an amount of change in the number of revolutions in a predetermined period of time. The control unit has a first control in which the rotation speed of the motor is limited to a predetermined value or less, and a second control in which the motor can be driven at a rotation speed exceeding the predetermined value,
The first control and the second control are configured to switch depending on whether the load exceeds or falls below the control switching threshold,
The work machine according to any one of claims 1 to 3, wherein the parameter includes the control switching threshold. The working machine according to claim 4, wherein the control switching threshold is lowered when the load exceeds a reference value. The work machine according to claim 4 or 5, wherein the control switching threshold is increased when the load falls below a reference value. The control unit has a soft start function that gradually increases the rotation speed of the motor toward a target value after the motor starts driving,
The working machine according to any one of claims 1 to 6, wherein the parameter includes a slope of increase in the rotation speed of the motor in the soft start function. 8. The work machine according to claim 7, wherein the gradient is steepened when the time from when the switch starts driving the motor to when the load is applied to the motor falls below a reference value. The work machine according to claim 7 or 8, wherein when the time from when the switch starts driving the motor to when the load is applied to the motor exceeds a reference value, the gradient is moderated. A winding switching unit for switching the winding form of the motor between a high-rotation winding and a high-torque winding,
the winding configuration is configured to switch when the load exceeds or falls below a winding switching threshold;
The work machine according to any one of claims 1 to 9, wherein the parameter includes the winding switching threshold. 11. The working machine according to claim 10, wherein the winding switching threshold is lowered when the time from start to stop of the motor exceeds a reference value. The work machine according to claim 10 or 11, wherein the winding switching threshold is increased when the time from start to stop of the motor is below a reference value. The work machine according to any one of claims 1 to 12, wherein the parameter is changed within a predetermined range.

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