Trigger switch, electric tool provided with same, method for controlling trigger switch, and control program

Abstract

This trigger switch (10) comprises a trigger (10a), a brush (15d), a detection unit (16aa), a sensor unit (15e), a trigger position detection unit (18), and a control unit (19). The brush (15d) is provided integrally with the trigger (10a). The sensor unit (15e) detects an operation amount of a push operation on the trigger (10a). The trigger position detection unit (18) detects the position of the trigger (10a). When the detection unit (16aa) detects movement of the brush (15d), the control unit (19) transitions to a start-up state, and when the trigger position detection unit (18) detects that the trigger (10a) has returned to an initial position after the push operation, the control unit maintains the start-up state for a prescribed time if the operation amount detected by the sensor unit (15e) was at least a prescribed threshold value, and transitions from the start-up state to a stop state if the operation amount of the push operation was less than the prescribed threshold value.

Description

Trigger switch, power tool equipped with the same, trigger switch control method and control program

[0001] The present invention relates to a trigger switch for driving a drive unit of, for example, a power tool, a power tool including the trigger switch, a control method for the trigger switch, and a control program.

[0002] In recent years, trigger switches have been used that control the operation of a drive unit of a power tool or the like by pressing a trigger. For example, Patent Document 1 discloses a trigger switch in which a switching mechanism (plunger) is provided with a brush that forms a sliding contact that has a function of switching the drive unit on and off, and another brush that forms a sliding contact that adjusts the output of the drive unit.

[0003] Japanese Patent Application Laid-Open No. 2020-30999

[0004] However, the above-mentioned conventional trigger switch has the following problem: The sliding contact of the trigger switch disclosed in the above publication has an electrode formed on a substrate and a brush that is a sliding electrode portion provided on a switching mechanism, and the movement of the switching mechanism switches between a state in which the brush contacts the electrode (a state in which the brush moves to a position in contact with the electrode) and a state in which the brush does not contact the electrode (a state in which the brush moves to a position not in contact with the electrode).

[0005] In this case, if the trigger switch is unintentionally pressed slightly due to vibrations or shocks that occur during transportation or movement, this can activate the microcomputer or IC on the circuit, resulting in unintended current consumption.The object of the present invention is to provide a trigger switch that can suppress unintended current consumption due to vibrations or shocks that occur during transportation or movement, as well as a power tool equipped with the trigger switch, a control method for the trigger switch, and a control program.

[0006] (Means for Solving the Problem) A trigger switch according to a first aspect of the present invention is a trigger switch that drives a drive unit in response to a depression of a trigger, and includes a trigger, a detectable portion, a detection portion, an operation amount detection portion, a trigger position detection portion, and a control portion. The trigger moves when the trigger is depressed. The detectable portion moves in conjunction with the trigger. The detection portion detects the detectable portion that moves in response to a depression of the trigger. The operation amount detection portion detects the amount of depression of the trigger. The trigger position detection portion detects the position of the trigger. The control portion transitions to an activated state when the detection portion detects movement of the detectable portion, and when the trigger position detection portion detects that the trigger has returned to its initial position after a depression, maintains the activated state for a predetermined time if the amount of depression detected by the operation amount detection portion is equal to or greater than a predetermined threshold, and transitions from the activated state to a stopped state if the amount of depression is less than the predetermined threshold.

[0007] In this case, when the control unit, which is activated by pressing the trigger, detects that the trigger has been returned to its initial position, it maintains the activation of the control unit if the amount of pressing of the trigger is equal to or greater than a threshold, and transitions to a stopped state if the amount of pressing of the trigger is less than the threshold. Here, this trigger switch is used, for example, to drive a drive motor (drive unit) mounted on a power tool or the like.

[0008] The detectable portion and the detecting portion included in the trigger switch may form NC (Normal Close) contacts that are in contact until the trigger is pressed and become non-contact when the trigger is pressed, or may form NO (Normal Open) contacts that are non-contact until the trigger is pressed and become contact when the trigger is pressed. This prevents unnecessary power consumption caused by the control portion remaining activated when the trigger is unintentionally pressed by a user due to vibrations, impacts, etc. during transportation, etc.

[0009] On the other hand, if the amount of depression of the trigger is equal to or greater than a predetermined threshold, the activated state is maintained for a predetermined period of time, thereby ensuring responsiveness to the trigger and avoiding operational delays. As a result, unintended current consumption due to vibrations and shocks that occur during transportation and movement can be suppressed while ensuring responsiveness to the trigger.

[0010] A trigger switch according to a second aspect of the present invention is the trigger switch according to the first aspect of the present invention, wherein the control unit sets a predetermined threshold value based on the depression position of the trigger that activates the controller on the main body side on which the drive unit is provided, thereby making it possible to determine whether to maintain the activation of the control unit based on the result of comparing the amount of depression of the trigger with the threshold value set based on the depression position that activates the controller on the main body side on which the trigger switch is mounted.

[0011] A trigger switch according to a third aspect of the present invention is the trigger switch according to the first or second aspect of the present invention, wherein the trigger position detection unit detects a state in which the detection unit detects or does not detect movement of the detectable part as the trigger being in its initial position. As a result, if the detectable part and the detection unit form an NC contact, the state in which the detection unit detects the detectable part, and if the detectable part and the detection unit form a NO contact, the state in which the detection unit does not detect the detectable part can be easily detected as the trigger being in its initial position in which it has not been pressed.

[0012] A trigger switch according to a fourth aspect of the present invention is the trigger switch according to the first or second aspect of the present invention, wherein the detecting portion and the detected portion constitute contacts that are in contact until the trigger is pressed and that become non-contact when the trigger is pressed. This makes it possible to reduce power consumption in a trigger switch that constitutes NC (Normal Close) contacts that are in contact until the trigger is pressed and that become non-contact when the trigger is pressed.

[0013] A trigger switch according to a fifth aspect of the present invention is the trigger switch according to the first or second aspect of the present invention, wherein the detecting portion and the detected portion constitute contacts that are in a non-contact state until the trigger is pressed and that come into contact when the trigger is pressed. This makes it possible to reduce power consumption in a trigger switch that constitutes a NO (Normal Open) contact that is in a non-contact state until the trigger is pressed and that comes into contact when the trigger is pressed.

[0014] A sixth aspect of the present invention provides a power tool including a main body having a drive unit and a trigger switch that drives the drive unit in response to a trigger depression. The trigger switch includes a trigger that moves when depressed, a detectable portion that moves in conjunction with the trigger, a detector that detects the movement of the detectable portion in response to the trigger depression, an operation amount detector that detects the amount of depression of the trigger, and a trigger position detector that detects the position of the trigger. The main body includes a drive unit and a control unit that transitions to an activated state when the detector detects the movement of the detectable portion, and that, when the trigger position detector detects that the trigger has returned to its initial position after depression, maintains the activated state for a predetermined time if the amount of depression detected by the operation amount detector is equal to or greater than a predetermined threshold, and transitions from the activated state to a stopped state if the amount of depression is less than the predetermined threshold.

[0015] In this case, when the control unit, which is activated by pressing the trigger, detects that the trigger has been returned to its initial position, it maintains the activation of the control unit if the amount of pressing of the trigger is equal to or greater than a threshold, and transitions to a stopped state if the amount of pressing of the trigger is less than the threshold. Here, this trigger switch is used, for example, to drive a drive motor (drive unit) mounted on a power tool or the like.

[0016] The detectable portion and the detecting portion included in the trigger switch may form NC (Normal Close) contacts that are in contact until the trigger is pressed and become non-contact when the trigger is pressed, or may form NO (Normal Open) contacts that are non-contact until the trigger is pressed and become contact when the trigger is pressed. This prevents unnecessary power consumption caused by the control portion remaining activated when the trigger is unintentionally pressed by a user due to vibrations, impacts, etc. during transportation, etc.

[0017] On the other hand, if the amount of depression of the trigger is equal to or greater than a predetermined threshold, the activated state is maintained for a predetermined period of time, thereby ensuring responsiveness to the trigger and avoiding operational delays. As a result, unintended current consumption due to vibrations and shocks that occur during transportation and movement can be suppressed while ensuring responsiveness to the trigger.

[0018] A seventh aspect of the present invention provides a method for controlling a trigger switch that drives a drive unit in response to a trigger depression operation, the method comprising the steps of: transitioning to an activated state when a detection unit detects movement of a detectable unit; when a trigger position detection unit detects that the trigger has returned to its initial position after the depression operation, maintaining the activated state for a predetermined time if the amount of depression operation detected by the operation amount detection unit is equal to or greater than a predetermined threshold; and transitioning from the activated state to a stopped state if the amount of depression operation is less than the predetermined threshold. The trigger switch comprises a trigger that moves in response to a depression operation, a detectable unit that moves in conjunction with the trigger, a detection unit that detects movement of the detectable unit in response to the trigger depression operation, an operation amount detection unit that detects the amount of depression of the trigger, and a trigger position detection unit that detects the position of the trigger.

[0019] In this case, when the control unit, which is activated by pressing the trigger, detects that the trigger has been returned to its initial position, it maintains the activation of the control unit if the amount of pressing of the trigger is equal to or greater than a threshold, and transitions to a stopped state if the amount of pressing of the trigger is less than the threshold. Here, this trigger switch is used, for example, to drive a drive motor (drive unit) mounted on a power tool or the like.

[0020] The detectable portion and the detecting portion included in the trigger switch may form NC (Normal Close) contacts that are in contact until the trigger is pressed and become non-contact when the trigger is pressed, or may form NO (Normal Open) contacts that are non-contact until the trigger is pressed and become contact when the trigger is pressed. This prevents unnecessary power consumption caused by the control portion remaining activated when the trigger is unintentionally pressed by a user due to vibrations, impacts, etc. during transportation, etc.

[0021] On the other hand, if the amount of depression of the trigger is equal to or greater than a predetermined threshold, the activated state is maintained for a predetermined period of time, thereby ensuring responsiveness to the trigger and avoiding operational delays. As a result, unintended current consumption due to vibrations and shocks that occur during transportation and movement can be suppressed while ensuring responsiveness to the trigger.

[0022] A control program for a trigger switch according to an eighth aspect of the present invention is a control program for a trigger switch that drives a drive unit in response to a depression operation of a trigger, the control program causing a computer to execute a control method for a trigger switch including the steps of: transitioning to an activated state when a detection unit detects movement of a detectable unit; when a trigger position detection unit detects that the trigger has returned to its initial position after the depression operation, maintaining the activated state for a predetermined time if the amount of depression operation detected by the operation amount detection unit is equal to or greater than a predetermined threshold; and transitioning from the activated state to a stopped state if the amount of depression operation is less than the predetermined threshold. The trigger switch includes a trigger that moves in response to a depression operation, a detectable unit that moves in conjunction with the trigger, a detection unit that detects movement of the detectable unit in response to a depression operation of the trigger, an operation amount detection unit that detects the amount of depression of the trigger, and a trigger position detection unit that detects the position of the trigger.

[0023] In this case, when the control unit, which is activated by pressing the trigger, detects that the trigger has been returned to its initial position, it maintains the activation of the control unit if the amount of pressing of the trigger is equal to or greater than a threshold, and transitions to a stopped state if the amount of pressing of the trigger is less than the threshold. Here, this trigger switch is used, for example, to drive a drive motor (drive unit) mounted on a power tool or the like.

[0024] The detectable portion and the detecting portion included in the trigger switch may form NC (Normal Close) contacts that are in contact until the trigger is pressed and become non-contact when the trigger is pressed, or may form NO (Normal Open) contacts that are non-contact until the trigger is pressed and become contact when the trigger is pressed. This prevents unnecessary power consumption caused by the control portion remaining activated when the trigger is unintentionally pressed by a user due to vibrations, impacts, etc. during transportation, etc.

[0025] On the other hand, if the amount of depression of the trigger is equal to or greater than a predetermined threshold, the activated state is maintained for a predetermined period of time, thereby ensuring responsiveness to the trigger and avoiding operational delays. As a result, unintended current consumption due to vibrations and shocks that occur during transportation and movement can be suppressed while ensuring responsiveness to the trigger.

[0026] (Effects of the Invention) The trigger switch according to the present invention can suppress unintended current consumption caused by vibrations, shocks, etc. that occur during transportation, movement, etc., while ensuring responsiveness to trigger operation.

[0027] 1 is a perspective view showing the external configuration of a power tool equipped with a trigger switch according to an embodiment of the present invention. FIG. 2 is a perspective view showing the configuration of the trigger switch equipped on the power tool of FIG. 1. FIG. 3 is a side view showing the internal configuration of the trigger switch of FIG. 2. FIG. 4 is a side view showing an example of the released state of the trigger switch of FIG. 2. FIG. 5 is a control block diagram showing the configuration of the power tool of FIG. 1. (a) is a perspective view showing the trigger switch in an off state (a state in which the brush and the board side are in contact). (b) is a perspective view showing the trigger switch in an on state (a state in which the brush and the board side are not in contact). (a) is a time chart showing start-up control when a small amount of depression is input into the trigger switch due to vibration, impact, etc. (b) is a time chart showing start-up control when a user inputs a depression operation into the trigger switch to use the power tool. FIG. 6 is a flowchart showing the processing flow of a trigger switch control method according to the present embodiment.

[0028] A trigger switch according to one embodiment of the present invention will be described below with reference to FIGS. 1 to 8. Note that in this embodiment, more detailed explanation than necessary may be omitted. For example, detailed explanations of well-known matters or redundant explanations of substantially identical configurations may be omitted. This is to avoid unnecessary redundancy in the following explanation and to facilitate understanding by those skilled in the art.

[0029] The applicant provides the accompanying drawings and the following description to enable those skilled in the art to fully understand the present invention, and is not intended to limit the subject matter recited in the claims. The trigger switch 10 according to this embodiment is mounted on a power tool 50 (see FIG. 1 ), such as an electric drill, an electric screwdriver, an electric wrench, or an electric grinder, which is equipped with a drive unit such as a motor. The trigger switch 10 according to this embodiment has a normally closed (NC) contact that is set to a non-contact state when a circuit provided inside the power tool 50 transitions from an on position to an off position.

[0030] (1) Power tool 50 As shown in FIG. 1, the power tool 50 of this embodiment includes a main body 20 that is held by a user of the power tool 50, and a trigger switch 10 that is attached to the main body 20 and receives a pressing operation by the user.

[0031] 1, the power tool 50 has a handle portion (main body 20) extending downward attached to a substantially cylindrical portion 21 to which a tool tip 51 is attached. In the following description, for convenience of explanation, the upper side in the orientation of the power tool 50 shown in FIG. 1 will be referred to as "up," the lower side as "down," the direction in which the trigger 10a of the trigger switch 10 is positioned (right in the drawing) as "front," and the direction in which the trigger 10a is pressed (left in the drawing) as "rear."

[0032] The main body 20 is provided with an openable door 20a and a window 20b through which the mounting state of the trigger 10a of the trigger switch 10 can be visually confirmed. In the released state shown in FIG. 1 , the trigger switch 10 is not depressed, and the tool bit 51 is not driven to rotate. When the user places his or her finger on the trigger 10a and depresses it toward the main body 20 (rearward) from the released state shown in FIG. 1 , the motor (drive unit) M1 (see FIG. 5 ) built into the main body 20 is driven to rotate the tool bit 51. The circuit configuration for controlling the driving and stopping of the motor M1 will be described in detail below.

[0033] (2) Trigger Switch 10 The trigger switch 10 of this embodiment is a switch operated by the user when performing various tasks using the power tool 50, and as shown in FIG. 2, includes a trigger 10a to which a pushing operation is input, a plunger 11a, a return spring 11b that biases the trigger 10a, a housing 12 contained in the main body 20 of the power tool 50, a covering member 13, and a switching lever 14 that switches the drive direction of the motor (drive unit) M1 (for example, the forward / reverse rotation direction of the tip tool 51).

[0034] The trigger 10a is a member that is depressed by the user, and its front surface is formed in an arc shape where the user places their finger during operation. The plunger 11a has a rod-shaped shaft 11aa and a drive switching mechanism 11ab formed continuously with the rear end of the shaft 11aa. The shaft 11aa supports the trigger 10a in a fitted state at its front end.

[0035] As shown in Figures 2 and 3, the housing 12 is a hollow case having a substantially rectangular parallelepiped shape, and is composed of a first cover 12a and a second cover 12b formed symmetrically on the left and right. A drive switching mechanism 11ab is housed in the internal space of the housing 12. A circuit board 16a is attached to the inner surface of the first cover 12a. A circuit (not shown) for driving the motor (drive unit) M1 is disposed on the circuit board 16a.

[0036] A substantially circular through-hole 12e is formed in the front surface of the housing 12, through which the rear end (other end) of the shaft 11aa passes. The periphery of the through-hole 12e protrudes forward in a cylindrical shape. A switching lever 14 is attached to the top surface of the housing 12. The interior space of the housing 12 is divided into two upper and lower chambers: a lower chamber 12c and an upper chamber 12d. The lower chamber 12c of the housing 12 houses a drive switching mechanism 11ab. The upper chamber 12d houses an operating direction switching mechanism 14a.

[0037] The drive switching mechanism 11ab opens and closes a circuit formed on the substrate 16a to control the motor (drive unit) M1. The drive switching mechanism 11ab moves back and forth in accordance with the movement of the shaft 11aa. That is, the drive switching mechanism 11ab moves between a pressed position and a released position in accordance with the pressing and releasing of the trigger 10a. That is, the drive switching mechanism 11ab moves backward when the trigger 10a is pressed, and the motor (drive unit) M1 is driven. On the other hand, the drive switching mechanism 11ab returns forward, and the driving of the motor (drive unit) M1 is stopped.

[0038] The return spring 11b is formed using a spring such as a compression coil spring. As shown in Figures 3 and 4, the return spring 11b is wound around the outer periphery of the shaft 11aa on the outside of the housing 12 and biases the shaft 11aa forward, in the direction opposite to the pushing direction. This causes the shaft 11aa, which has been pushed rearward together with the trigger 10a, to return to the forward release position. The front end of the return spring 11b is engaged with the shaft 11aa, and the rear end is engaged with the periphery of the through-hole 12e of the housing 12.

[0039] Furthermore, as shown in FIG. 3 , the internal space of the housing 12 is provided with a brush (detected part) 15d, a flat cable 16c, a cam 16d, a spring 16e, a cam plate 16f, a switching spring 16g, a roller 16h, a roll pin 17a, an E-ring 17b, and a rubber seal 17c. The brush 15d is attached to the side of the drive switching mechanism 11ab and moves in conjunction with the trigger 10a when the trigger 10a is pressed. When the trigger 10a is in its initial position, the brush 15d is detected in contact with the detector 16aa provided on the circuit board 16a. When the trigger 10a is pressed, the brush 15d is released from contact with the detector 16aa provided on the circuit board 16a and is no longer detected.

[0040] When the pressing operation of the trigger 10a exceeds a predetermined threshold (e.g., 0.1 to 0.3 mm), the brush 15d is no longer detected by the detection unit 16aa, thereby detecting the pressing operation of the trigger 10a. The flat cable 16c is provided for inputting power from the power tool 50 or outputting a signal to the power tool 50.

[0041] Cam 16d is provided to convert the rotational movement of switching lever 14 into linear movement and to move the position of cam plate 16f in accordance with the movement of switching lever 14. Spring 16e is disposed between cam 16d and cam plate 16f, and is provided to apply a biasing force in a direction that presses cam plate 16f toward base plate 16a, thereby maintaining a constant distance between cam plate 16f and base plate 16a.

[0042] The cam plate 16f is fixed to the cam 16d and is provided to transmit the operational state (position) of the switching lever 14 to the base plate 16a, and its position relative to the base plate 16a changes depending on the position of the switching lever 14. The switching spring 16g is provided to bias the roller 16h in a direction pressing it against the switching plate 16i, thereby generating an operational reaction force when the switching lever 14 rotates.

[0043] The roller 16h slides on the uneven surface of the switching plate 16i as the switching lever 14 rotates while receiving the biasing force of the switching spring 16g, thereby transmitting an operation reaction force corresponding to the uneven surface to the switching lever 14. The roll pin 17a is provided to fix the trigger cap of the trigger 10a to the plunger 11a.

[0044] The E-ring 17b is fixed onto the plunger 11a and is provided to transmit the reaction force of the return spring 11b to the plunger 11a. The seal rubber 17c is provided to fill structural gaps between the switch lever 14 and the second and first covers 12b and 12a to ensure sealing. The covering member 13 is formed in a generally cylindrical bellows shape that expands and contracts in the axial direction and covers the outer periphery of the shaft portion 11aa and the return spring 11b outside the housing portion 12. The front end of the covering member 13 is attached to the shaft portion 11aa. The rear end of the covering member 13 is attached so as to cover the protruding portion of the periphery of the through-hole 12e of the housing portion 12. The covering member 13 is formed using a flexible, airtight material such as rubber.

[0045] The operating direction switching mechanism 14a is attached to the switching lever 14, and switches the operating direction of the motor (drive unit) M1 by switching the wiring of the circuit opened and closed by the drive switching mechanism 11ab when the switching lever 14 is operated. The switching lever 14 is a member that swings left and right in response to a switching operation from the user to switch the drive direction of the motor (drive unit) M1, and transmits the swinging motion to the operating direction switching mechanism 14a. Furthermore, when the switching lever 14 is operated to be positioned in the middle of its swing range, the switching lever 14 functions as a locking mechanism that prevents the trigger 10a from being pressed.

[0046] The trigger switch 10, configured as described above, is incorporated into the power tool 50 and accepts user operation. A user of the power tool 50 performs operations such as depressing the trigger 10a and swinging the switch lever 14. When the trigger 10a is depressed, it moves rearward. As the trigger 10a moves rearward, the shank 11aa attached to the trigger 10a also moves rearward. As the shank 11aa moves rearward, the drive switching mechanism 11ab connected to the rear end of the shank 11aa also moves rearward, driving the motor (drive unit) M1. As the shank 11aa moves rearward, the return spring 11b and the covering member 13 are compressed in the axial direction.

[0047] To stop the motor (drive unit) M1, the user releases the pressure on the trigger 10a. When the pressure on the trigger 10a is released, the biasing force of the return spring 11b moves the trigger 10a, the shaft 11aa, and the drive switching mechanism 11ab forward and returns to the release position. Furthermore, as the shaft 11aa moves forward, the return spring 11b and the covering member 13 extend in the axial direction.

[0048] The trigger switch 10 includes a sensor unit (operation amount detection unit) 15e that detects the movement or position of the trigger 10a when the trigger 10a is pressed, and a switching unit 15 that switches the motor (drive unit) M1 between driving and stopping in response to the movement of the trigger 10a. The switching unit 15 has a switching circuit 15c. The switching circuit (operation amount detection unit) 15c is configured using sensors such as optical sensors, magnetic sensors, electrostatic sensors, and electrical resistance sensors. The switching circuit 15c outputs an ON signal or OFF signal in response to the position of the trigger 10a detected by the sensor unit 15e that detects the movement or position of the trigger 10a in a non-contact manner.

[0049] The switching circuit 15c may output an ON or OFF signal in response to contact between a movable contact and a fixed contact caused by movement or position of the trigger 10a. A trigger plate 15a made of conductive metal is provided on the left side of the switch in the drive switching mechanism 11ab. As shown in FIG. 3, the trigger plate 15a is attached to the drive switching mechanism 11ab via two springs 16b and is biased toward the first cover 12a by the springs 16b.

[0050] Furthermore, a detector 15b (shown by the two-dot chain line in FIG. 4) capable of detecting the position of the trigger plate 15a is formed at a rearward position on the circuit board 16a attached to the inside surface of the first cover 12a. That is, in the released state where the trigger 10a is not being pressed, the trigger plate 15a is in a position (off state) that is disengaged from the detector 15b in a side view, as shown in FIG. 4. At this time, the switching circuit 15c for driving the motor (drive unit) M1 is in a released state, and the rotation of the motor (drive unit) M1 is stopped.

[0051] From this state, when the shaft 11aa and the drive switching mechanism 11ab move rearward by pressing the trigger 10a, the trigger plate 15a and the detector 15b overlap (face each other) in a side view (ON state) when the shaft 11aa and the drive switching mechanism 11ab move rearward by a predetermined distance, and the motor (drive unit) M1 is driven. In this embodiment, the position of the trigger plate 15a, which changes as the trigger 10a is pressed, is sensed, and the motor (drive unit) M1 is controlled so that its rotation speed increases.

[0052] <Control Configuration> Here, a control configuration of the power tool 50 of this embodiment will be described. As shown in Fig. 5, the power tool 50 transmits and receives signals between the main body 20 and the trigger switch 10. The main body 20 has a control unit 22 and a motor (drive unit) M1.

[0053] The trigger switch 10 has a sensor unit (operation amount detection unit) 15e, a trigger position detection unit 18, and a control unit 19. The trigger position detection unit 18 detects the brush 15d (NC contact) detected by the detection unit 16aa on the circuit board 16a as the trigger 10a being in its initial position. The control unit 19 outputs a drive signal to the main body 20 in response to signals from the sensor unit (operation amount detection unit) 15e and the trigger position detection unit 18. The control unit 19 is a circuit configured using, for example, a microcomputer using integrated circuits such as various LSIs and VLSIs, electronic elements, and various terminals, and is disposed on the circuit board 16a inside the housing 12.

[0054] The control unit 19 also receives signals from the sensor unit 15e and the trigger position detection unit 18 as inputs, performs various processes based on the inputs, and outputs a drive signal for driving the motor M1 to the control unit 22 included in the main body 20 of the power tool 50. In the power tool 50 of this embodiment, when the contact between the brush 15d and the detection unit 16aa on the circuit board 16a is released as the trigger 10a is pressed, a signal (ON signal) is transmitted from the switching circuit 15c. In other words, as the trigger 10a is pressed further, the control unit 19 transitions from a stopped state (sleep state) to an activated state.

[0055] <Pushing the Trigger 10a> Next, we will explain the states of the switching circuit 15c and the control unit 22 and the change in the device rotation speed when the trigger is pushed. When the trigger switch 10 is in the released state, as shown in Figure 6(a), the brush 15d is in contact with the circuit board 16a. In this state, the control unit 22 is in a stopped (sleep) state. Furthermore, the switching circuit 15c is in the OFF state (the trigger plate 15a is in the OFF position), and the motor M1 is stopped.

[0056] When the trigger 10a is pressed from this state, the plunger 11a moves backward. As the plunger 11a moves backward, the brush 15d transitions to an OFF state, where it is no longer in contact with the detector 16aa on the circuit board 16a, as shown in FIG. 6B, and the control unit 19 of the trigger switch 10 is activated. As the trigger 10a continues to be pressed, the plunger 11a moves further backward, transitioning to an ON state where the trigger plate 15a overlaps the detector 15b, and the motor M1 begins to operate. As the trigger 10a is pressed further, the signal from the switching circuit 15c changes, and the rotational speed of the motor M1 increases.

[0057] <Method of controlling trigger switch 10> With the above-described configuration, when the trigger 10a of the trigger switch 10 of this embodiment is pressed, the brush 15d, which moves in conjunction with the trigger 10a, is released from contact with the substrate 16a, and a signal is output to activate the control unit 19 within the trigger switch 10, thereby activating the control unit 19.

[0058] At this time, if the trigger 10a is slightly pressed due to vibration, impact, or the like and the trigger 10a immediately returns to its initial position (a position where there is no pressing operation), unnecessary power consumption will be generated if the control unit 19 is maintained in an activated state to improve the operational responsiveness of the trigger 10a. Therefore, in the trigger switch 10 of this embodiment, as shown in Fig. 7(a), if the trigger 10a is slightly pressed due to vibration, impact, or the like during transportation, for example, and the trigger 10a immediately returns to its initial position (a position where there is no pressing operation), the control unit 19 is activated and then immediately controlled to switch from the activated state to a stopped state (sleep state).

[0059] More specifically, as shown in FIG. 7(a), when the trigger 10a is pressed and the stroke of the trigger 10a exceeds the contact OFF position between the brush 15d and the detection unit 16aa on the substrate 16a side but returns to the initial position without reaching a predetermined threshold (amount of operation), a start signal to start the control unit 19 is output, and the control unit 19 is immediately transitioned to a stopped state (sleep state).

[0060] As a result, even if the trigger 10a is pressed due to vibration, impact, or the like, if the trigger 10a immediately returns to the initial position, it is determined that the power tool 50 is not intended to be used, and the control unit 19 is immediately switched to a stopped state each time without maintaining the activated state, thereby reducing unnecessary power consumption. On the other hand, as shown in Figure 7(b), if the trigger 10a is pressed and the stroke of the trigger 10a exceeds the contact OFF position and the amount of operation exceeds a predetermined threshold, a start signal for activating the control unit 19 is output, and the activated state of the control unit 19 is maintained for X seconds even after the trigger 10a returns to the initial position (contact OFF position).

[0061] As a result, when a user operates the trigger 10a to use the power tool 50 and the stroke of the trigger 10a exceeds a predetermined threshold, the control unit 19 remains activated, thereby ensuring the operational responsiveness of the power tool 50 when the trigger switch 10 is operated and preventing operational delays. The control unit 19 sets the predetermined threshold value for the stroke of the trigger 10a based on the depression position of the trigger 10a for activating the control unit 22 on the main body 20 side where the motor M1 is provided.

[0062] Here, the depression position of the trigger 10a for activating the control unit 22 on the main body 20 side is, for example, the position at which the trigger plate 15a is detected by the detection unit 15b. This makes it possible to determine whether to maintain the activation of the control unit 19 based on the result of comparing the amount of depression of the trigger 10a with a threshold set based on the depression position that activates the control unit 22 on the main body 20 side on which the trigger switch 10 is mounted.

[0063] Note that, although a short setting of X seconds reduces power consumption, the control unit 19 must repeatedly start and stop each time, which causes a delay in the operation of the power tool 50. Therefore, in consideration of the usability of the power tool 50, it is preferable that X seconds is not set too short, but is set to a predetermined length or longer.

[0064] <Control Method of Trigger Switch 10> The control method of the trigger switch 10 of this embodiment will be described below with reference to the flowchart shown in FIG. 8. That is, in step S11, the control unit 19 of the trigger switch 10 is in a stopped state (sleep state), and in step S12, the control unit waits until the mechanical contact between the brush 15d and the detection unit 16aa on the circuit board 16a is turned OFF by pressing the trigger 10a. When the mechanical contact transitions to the OFF state, the process proceeds to step S13. Next, in step S13, because the mechanical contact has been turned OFF in step S12, the control unit 19 of the trigger switch 10 transitions from the stopped state to the activated state.

[0065] Next, in step S14, it is determined whether the stroke amount of the depression operation of the trigger 10a is less than a predetermined threshold value PT1. If the stroke amount is less than the predetermined threshold value PT1, the process proceeds to step S15. If the stroke amount is equal to or greater than the predetermined threshold value PT1, the process proceeds to step S16. Next, in step S15, since it was determined in step S14 that the stroke amount is less than the predetermined threshold value PT1, the activation signal is set to Low.

[0066] On the other hand, in step S16, since it was determined in step S14 that the stroke amount is equal to or greater than the predetermined threshold value PT1, the activation signal is set to High and maintained at High until the stroke amount becomes less than the threshold value PT1, thereby driving the motor M1 of the power tool 50 to rotate, and various tasks can be performed using the power tool 50.

[0067] Next, in step S17, it is determined whether the activation signal that was set to Low in step S15 has become High at least once, and if it has become High at least once, the process proceeds to step S18, otherwise the process proceeds to step S19. Next, in step S18, since it was determined in step S17 that the activation signal that was set to Low in step S15 has become High at least once, it is determined whether X seconds have passed.

[0068] If it is determined that X seconds have elapsed, the process returns to step S11. If X seconds have not elapsed, the process proceeds to step S20. By maintaining the control unit 19 in an activated state for X seconds, the operation responsiveness to the trigger 10a can be ensured and operational delays can be avoided. Meanwhile, in step S19, it is determined whether the mechanical contact is ON because it was determined in step S17 that the activation signal, which was set to Low in step S15, has not been set to High even once.

[0069] If the mechanical contact is ON, the trigger 10a has returned to its initial position, and the process returns to the sleep state of step S11. If the mechanical contact is not ON, the trigger 10a has not returned to its initial position, and the process returns to step S14 to determine whether the stroke amount of the trigger 10a is less than a predetermined threshold value PT1. Meanwhile, in step S20, it is determined whether the mechanical contact is OFF because it was determined in step S17 that the activation signal set to Low in step S15 has been High at least once, and it was determined in step S18 that X seconds have elapsed. If the mechanical contact is OFF, the trigger 10a has been pressed, and the process returns to step S13 to enter the activated state. On the other hand, if the mechanical contact is not OFF (is ON), the process returns to step S18, and it is repeatedly determined whether X seconds have elapsed until the mechanical contact is OFF.

[0070] <Major Features> The trigger switch 10 of this embodiment is a switch that drives the motor M1 in response to a pressing operation on the trigger 10a, and includes the trigger 10a, a brush 15d, a detection unit 16aa, a sensor unit 15e, a trigger position detection unit 18, and a control unit 19. The trigger 10a moves in response to a pressing operation. The brush 15d moves in conjunction with the trigger 10a. The detection unit 16aa detects the brush 15d that moves in response to a pressing operation on the trigger 10a. The sensor unit 15e detects the amount of pressing operation on the trigger 10a. The trigger position detection unit 18 detects the position of the trigger 10a. The control unit 19 transitions to an activated state when the detection unit 16aa detects the movement of the brush 15d, and when the trigger position detection unit 18 detects that the trigger 10a has returned to its initial position after being pressed, if the sensor unit 15e detects that the amount of pressing operation is greater than or equal to a predetermined threshold, the control unit 19 maintains the activated state for a predetermined time, or transitions from the activated state to a stopped state if the amount of pressing operation is less than the predetermined threshold.

[0071] This prevents unnecessary power consumption caused by unintentional pressing of the trigger 10a by the user due to vibrations, shocks, etc., during transportation, etc., which would otherwise cause the control unit 19 to remain activated. On the other hand, if the amount of pressing of the trigger 10a is equal to or greater than a predetermined threshold, the control unit 19 remains activated for a predetermined period of time, thereby ensuring responsiveness to the operation of the trigger 10a and avoiding operational delays. As a result, unintentional current consumption caused by vibrations, shocks, etc., that occur during transportation, movement, etc. can be suppressed while ensuring responsiveness to the operation of the trigger 10a.

[0072] [Other Embodiments] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the invention.

[0073] (A) In the above embodiment, the present invention has been described as being implemented as a trigger switch and a method for controlling the trigger switch. However, the present invention is not limited to this. For example, the present invention may be implemented as a control program that causes a computer to execute the above-described method for controlling the trigger switch.

[0074] This control program is stored in a memory (storage unit) mounted on the trigger switch, and a CPU reads the control program stored in the memory and causes the hardware to execute each step. More specifically, the CPU reads the control program and executes each of the steps described above, thereby achieving the same effects as described above. The present invention may also be realized as a recording medium storing the control program for the trigger switch.

[0075] (B) In the above embodiment, an example was described in which the control unit 19 provided on the trigger switch 10 determines whether to transition from the activated state to the deactivated state when the trigger 10a is pressed. However, the present invention is not limited to this. For example, a control unit (controller) provided on the main body of the power tool may be configured to determine whether to transition from the activated state to the deactivated state.

[0076] (C) In the above embodiment, the trigger switch 10 is described as an example of a normally closed (NC) contact that is released when a circuit provided inside the power tool 50 transitions from an on position to an off position. However, the present invention is not limited to this. For example, the present invention may be applied to a trigger switch that is a normally open (NO) contact that is released when a circuit provided inside the power tool transitions from an off position to an on position.

[0077] (D) In ​​the above embodiment, the present invention has been described as being applied to a trigger switch 10 mounted on a power tool 50. However, the present invention is not limited to this. For example, the present invention may be applied to trigger switches mounted on other devices such as vacuum cleaners and chainsaws.

[0078] <Note> A trigger switch according to a first aspect of the present invention is a trigger switch that drives a drive unit in response to a trigger depression operation, and comprises: the trigger that moves in response to the depression operation; a detectable part that moves in conjunction with the trigger; a detection part that detects the movement of the detectable part in accordance with the trigger depression operation; an operation amount detection part that detects the amount of the depression operation on the trigger; a trigger position detection part that detects the position of the trigger; and a control part that transitions to an activated state when the detection part detects the movement of the detectable part, and that, when the trigger position detection part detects that the trigger has returned to its initial position after the depression operation, maintains the activated state for a predetermined time if the amount of the depression operation detected by the operation amount detection part is equal to or greater than a predetermined threshold, or transitions from the activated state to a stopped state if the amount of the depression operation is less than the predetermined threshold.

[0079] A trigger switch according to a second aspect of the present invention is the trigger switch according to the first aspect of the present invention, wherein the control unit sets the predetermined threshold value based on a depression position of the trigger that activates a controller on a main body side where the drive unit is provided.A trigger switch according to a third aspect of the present invention is the trigger switch according to either the first or second aspect of the present invention, wherein the trigger position detection unit detects a state in which the detection unit detects or does not detect the detectable part as the trigger being in its initial position.

[0080] A trigger switch according to a fourth invention is the trigger switch according to any one of the first to third inventions, wherein the detecting portion and the detected portion constitute contacts that are in a contact state until the trigger is pressed, and that become a non-contact state when the trigger is pressed.A trigger switch according to a fifth invention is the trigger switch according to any one of the first to third inventions, wherein the detecting portion and the detected portion constitute contacts that are in a non-contact state until the trigger is pressed, and that become a contact state when the trigger is pressed.

[0081] The trigger switch of the present invention has the effect of suppressing unintended current consumption caused by vibrations, shocks, etc. that occur during transportation, movement, etc., and therefore can be widely used as a switch for driving various driving parts.

[0082] 10 Trigger switch 10a Trigger 11a Plunger 11aaa Shaft portion 11ab Drive switching mechanism 11b Return spring 12 Housing portion 12a First cover 12b Second cover 12c Lower chamber 12d Upper chamber 12e Through hole 13 Covering member 14 Switching lever 14a Operation direction switching mechanism 15 Switching portion 15a Trigger plate 15b Detection portion 15c Switching circuit 15d Brush (detected portion) 15e Sensor portion (operation amount detection portion) 16a Board 16aa Detection portion 16b Spring 16c Flat cable 16d Cam 16e Spring 16f Cam plate 16g Switching spring 16h Roller 17a Roll pin 17b E-ring 17c Seal rubber 18 Trigger position detection unit 19 Control unit 20 Main body unit 20a Door unit 20b Window unit 21 Approximately cylindrical portion 22 Control unit (controller) 50 Power tool 51 Tool tip M1 Motor (drive unit)

Claims

1. A trigger switch that drives a drive unit in response to a trigger depression operation, comprising: the trigger that moves in response to the depression operation; a detectable part that moves in conjunction with the trigger; a detection part that detects the detectable part that moves in response to the trigger depression operation; an operation amount detection part that detects the amount of the depression operation on the trigger; a trigger position detection part that detects the position of the trigger; and a control part that transitions to an activated state when the detection part detects the movement of the detectable part, and when the trigger position detection part detects that the trigger has returned to its initial position after the depression operation, maintains the activated state for a predetermined time if the amount of the depression operation detected by the operation amount detection part is equal to or greater than a predetermined threshold, or transitions from the activated state to a stopped state if the amount of the depression operation is less than the predetermined threshold.

2. The trigger switch according to claim 1, wherein the control unit sets the predetermined threshold value based on the depression position of the trigger that activates the controller on the main body side where the drive unit is provided.

3. A trigger switch according to claim 1 or 2, wherein the trigger position detection unit detects a state in which the detection unit detects or does not detect the detected part as the trigger being in its initial position.

4. A trigger switch as claimed in claim 1 or 2, wherein the detecting part and the detected part are in contact with each other until the trigger is pressed, and form contacts that become non-contact when the trigger is pressed.

5. A trigger switch as claimed in claim 1 or 2, wherein the detecting part and the detected part are in a non-contact state until the trigger is pressed, and constitute contacts that come into contact when the trigger is pressed.

6. A power tool comprising a main body provided with a drive unit, and a trigger switch that drives the drive unit in response to a pressing operation on a trigger, wherein the trigger switch has: the trigger that moves in response to the pressing operation; a detectable part that moves in conjunction with the trigger; a detection part that detects the movement of the detectable part in response to the pressing operation on the trigger; an operation amount detection part that detects the amount of the pressing operation on the trigger; and a trigger position detection part that detects the position of the trigger, and wherein the main body has: the drive unit; and a control part that transitions to an activated state when the detection part detects the movement of the detectable part, and that, when the trigger position detection part detects that the trigger has returned to its initial position after the pressing operation, maintains the activated state for a predetermined time if the amount of the pressing operation detected by the operation amount detection part is equal to or greater than a predetermined threshold, or transitions from the activated state to a stopped state if the amount of the pressing operation is less than the predetermined threshold.

7. A control method for a trigger switch that drives a drive unit in response to a trigger depression operation, the trigger switch comprising: the trigger that moves in response to the depression operation; a detectable part that moves in conjunction with the trigger; a detection part that detects the movement of the detectable part in accordance with the depression operation on the trigger; an operation amount detection part that detects the amount of the depression operation on the trigger; and a trigger position detection part that detects the position of the trigger, the control method for a trigger switch comprising: a step of transitioning to an activated state when the detection part detects the movement of the detectable part; a step of maintaining the activated state for a predetermined time when the trigger position detection part detects that the trigger has returned to its initial position after the depression operation and the amount of the depression operation detected by the operation amount detection part is equal to or greater than a predetermined threshold; and a step of transitioning from the activated state to a stopped state when the amount of the depression operation is less than the predetermined threshold.

8. A control program for a trigger switch that drives a drive unit in response to a trigger depression operation, the trigger switch comprising: the trigger that moves in response to the depression operation; a detectable unit that moves in conjunction with the trigger; a detection unit that detects the movement of the detectable unit in response to the trigger depression operation; an operation amount detection unit that detects the amount of the depression operation on the trigger; and a trigger position detection unit that detects the position of the trigger, the control program for a trigger switch that causes a computer to execute a control method for a trigger switch comprising the steps of: transitioning to an activated state when the detection unit detects movement of the detectable unit; maintaining the activated state for a predetermined time when the trigger position detection unit detects that the trigger has returned to its initial position after the depression operation and if the amount of the depression operation detected by the operation amount detection unit is equal to or greater than a predetermined threshold; and transitioning from the activated state to a stopped state if the amount of the depression operation is less than the predetermined threshold.

Images