This application claims priority to Japanese Patent Application No. 2021-108913 filed on Jun. 30, 2021, the contents of which are incorporated herein by reference.
The present disclosure relates to a switch including a movable unit that moves in response to an operation.
A trigger switch is widely used to control the operation of a power tool in response to a depressing operation. The trigger switch is to have higher airtightness, or for example, to be waterproof or dustproof. The switch described in, for example, Patent Literature 1 includes, for a circuit for the trigger, a housing with increased airtightness by simplifying the joint between a case and a cover in the housing.
The trigger that moves in response to an operation extends through the housing. As the trigger moves, the inner volume of the housing changes with the change in the flow of air, thus causing the housing to be less airtight.
A switch according to one or more embodiments that may easily achieve airtightness.
A switch according to one or more embodiments is a switch for driving a drive unit. The switch may include a movable unit movable in response to an operation. The drive unit is drivable in response to movement of the movable unit. The switch may include an operation-linked unit movable in response to the movement of the movable unit receiving the operation and an operation follower unit spaced from the operation-linked unit. The operation follower unit is movable in response to movement of the operation-linked unit with a magnetic force between the operation follower unit and the operation-linked unit. At least one of the operation-linked unit or the operation follower unit is magnetic. The drive unit is drivable in response to movement of the operation follower unit.
The switch may further include a chamber accommodating the operation follower unit. The operation follower unit accommodated in the chamber is spaced from the operation-linked unit.
In the switch, the drive unit is drivable based on a result of detecting the movement of the operation follower unit contactlessly.
The switch may further include an electrode adjacent to a movable range of the operation follower unit. The operation follower unit is dielectric. The drive unit is drivable based on a result of detecting the movement of the operation follower unit contactlessly as a change in a capacitance of a capacitor formed with the operation follower unit and the electrode.
The switch may further include a fixed contact. The operation follower unit includes a slider slidable on the fixed contact in response to the movement of the operation follower unit. The drive unit is drivable based on a result of detecting the movement of the operation follower unit as a change in a conductive state or an electric resistance value of the fixed contact.
The switch may further include a switch member operable in response to a switching operation to switch a driving mode of the drive unit, a switch-linked unit movable in response to an operation of the switch member receiving the switching operation, and a switch follower unit spaced from the switch-linked unit. The switch follower unit is movable in response to movement of the switch-linked unit with a magnetic force between the switch follower unit and the switch-linked unit. At least one of the switch-linked unit or the switch follower unit has magnetism. The driving mode of the drive unit is switchable in response to movement of the switch follower unit.
A switch according to one or more embodiments is a switch for driving a drive unit. The switch may include a movable unit movable in response to an operation. The drive unit is drivable in response to movement of the movable unit. The switch includes a switch member operable in response to a switching operation to switch a driving mode of the drive unit, a switch-linked unit movable in response to an operation of the switch member receiving the switching operation, and a switch follower unit spaced from the switch-linked unit. The switch follower unit is movable in response to movement of the switch-linked unit with a magnetic force between the switch follower unit and the switch-linked unit. At least one of the switch-linked unit or the switch follower unit is magnetic. The driving mode of the drive unit is switchable in response to movement of the switch follower unit.
The switch may further include a chamber accommodating the switch follower unit. The switch follower unit accommodated in the chamber is spaced from the switch-linked unit.
The switch is incorporated into an electric device including the drive unit drivable in response to an electric signal. The switch may further include an output unit that outputs the electric signal to drive the drive unit. The output unit outputs the electric signal to drive the drive unit.
The switch according to one or more embodiments may easily achieve airtightness by using a magnetic force to separate components operable in response to an operation from components for driving a drive unit.
One or more embodiments will now be described with reference to the drawings.
A switch according to one or more embodiments of the present disclosure is incorporated in various electric devices such as electric drills, electric saws, electric screwdrivers, electric wrenches, electric grinders, and other power tools including a motor or another drive unit as, for example, a trigger switch. The switch according to one or more embodiments of the present disclosure may be implemented in various manners described in first and second embodiments below. As the switch according to the embodiments of the present disclosure used as a trigger switch, a switch TS illustrated in the drawings and an electric device ET incorporating the switch TS will be described with reference to the drawings.
The switch TS includes a substantially rectangular housing 2, the movable unit 1, and a switch lever 3. The housing 2 is incorporated into the electric device ET. The movable unit 1 as a trigger can be depressed by the user. The switch lever 3 (switch member) receives a switching operation for switching the driving direction of the drive unit M. The switch lever 3 performs a switching operation such as switching the rotation direction of an electric screwdriver between the forward rotation and the reverse rotation. The housing 2 includes a first half body 20 on the right and a second half body 21 on the left joined together. A communication line 22 extends from the bottom surface of the housing 2. The communication line 22 transmits signals for driving the drive unit M.
The internal structure of the switch TS will now be described.
The switch TS includes, for example, an operation-linked unit 4, a switch-linked unit 5, an engagement member 6, an operation follower unit 7, a switch follower unit 8, and a holder 9 in the housing 2, in addition to the movable unit 1 and the switch lever 3 described above. The second half body 21 of the housing 2 has a space as a chamber 210 for accommodating the operation follower unit 7, the switch follower unit 8, and the holder 9. The chamber 210 is a rectangular box. The chamber 210 is hermetically sealed. The chamber 210 accommodates the holder 9 for holding components such as the operation follower unit 7 and the switch follower unit 8. The operation follower unit 7 and the switch follower unit 8 held by the holder 9 are hermetically sealed in the chamber 210. The components such as the operation follower unit 7 and the switch follower unit 8 accommodated in the chamber 210 are thus spaced from, for example, the operation-linked unit 4 and the switch-linked unit 5.
The second half body 21 is molded with the space as the chamber 210 having an open bottom surface. The space as the chamber 210 in the molded second half body 21 receives the components such as the operation follower unit 7, the switch follower unit 8, and the holder 9 from below. The bottom surface of the space is then sealed with a resin. The chamber 210 with the above described structure is highly airtight, or for example, is waterproof or dustproof.
The components in the switch TS including the movable unit 1 will now be described with reference to
The shaft 11 in the movable unit 1 accommodated in the housing 2 has a rear end in the depressing direction to which the operation-linked unit 4 is attached. The operation-linked unit 4 moves as the movable unit 1 moves. The operation-linked unit 4 is a substantially rectangular prism. The operation-linked unit 4 is attached to the shaft 11 on its front side surface. The operation-linked unit 4 moves back and forth as the movable unit 1 moves. The operation-linked unit 4 incorporates a first magnet 40 and is thus magnetic. The first magnet 40 is a permanent magnet. The first magnet 40 is located to have its magnetic poles positioned in the front-rear direction, for example, the south pole positioned frontward and the north pole positioned rearward. The first magnet 40 forms a magnetic field that affects the operation follower unit 7.
The switch-linked unit 5 is located below the switch lever 3 in a manner movable back and forth. The switch-linked unit 5 moves as the switch lever 3 moves. The switch-linked unit 5 is a substantially rectangular prism. The switch-linked unit 5 includes a substantially cylindrical cam protrusion 50 on its upper surface. The cam protrusion 50 protruding on the upper surface is loosely fitted in the cam groove 34 on the bottom surface of the switch lever 3. The cam protrusion 50 and the cam groove 34 are engaged with each other, which allows the action portion 32 in the switch lever 3 to function as a cam driver and allows the switch-linked unit 5 to function as a cam follower. The switch-linked unit 5 incorporates a second magnet 51 on its left side surface and is thus magnetic. The second magnet 51 is a permanent magnet. The second magnet 51 forms a magnetic field that affects the switch follower unit 8.
The engagement member 6 is located behind the switch lever 3. The engagement member 6 is engaged with the switch lever 3 as a pusher for pressing the switch lever 3 forward. The engagement member 6 has a front end facing the switch lever 3. The front end is M-shaped as viewed in plan. The engagement member 6 includes a pusher spring 60 at its rear. The pusher spring 60 is, for example, a coil spring and urges the engagement member 6 forward.
In response to an operation for swinging the switch lever 3 performed by the user, the switch lever 3 swings. The engagement member 6 urged by the pusher spring 60 is engaged with the engagement vertex 33 while pressing the engagement vertex 33 in the switch lever 3 with the recess or the side portion of the M-shape. The switch lever 3 is thus held at the swing position.
The operation follower unit 7 is a substantially rectangular plate. The operation follower unit 7 is accommodated in the lower chamber 92 with a direction normal to its surfaces being the right-left direction. The operation follower unit 7 has a height and a lateral width slightly shorter than the height and the lateral width of the lower chamber 92. The operation follower unit 7 is thus movable back and forth in the lower chamber 92. The operation follower unit 7 is a magnetic body formed from a plastic magnetic material and is magnetic. The operation follower unit 7 forms the capacitor as a dielectric. The operation follower unit 7 is located to have its magnetic poles positioned in the front-rear direction, for example, the north pole positioned frontward and the south pole positioned rearward. The north pole and the south pole of the operation follower unit 7 are opposite to the north pole and the south pole of the adjacent first magnet 40, which causes the north pole of the operation follower unit 7 frontward in the operation follower unit 7 to face the south pole of the first magnet 40 rearward in the first magnet 40, and the south pole of the operation follower unit 7 rearward in the operation follower unit 7 to face the north pole of the first magnet 40 rearward in the first magnet 40. The operation follower unit 7 and the first magnet 40 thus attract each other. The operation follower unit 7 moves back and forth accordingly as the first magnet 40 moves in the front-rear direction.
The switch follower unit 8 is a substantially rectangular plate. The switch follower unit 8 is accommodated in the upper chamber 93 with a direction normal to its surfaces being the right-left direction. The switch follower unit 8 has a height and a lateral width slightly shorter than the height and the lateral width of the upper chamber 93. The switch follower unit 8 is thus movable back and forth in the upper chamber 93. The switch follower unit 8 is a magnetic body formed from a plastic magnetic material and is magnetic. The switch follower unit 8 forms the capacitor as a dielectric. The switch follower unit 8 is located to cause the switch follower unit 8 and the second magnet 51 to attract each other. The switch follower unit 8 moves back and forth accordingly as the second magnet 51 moves in the front-rear direction.
The electrodes 900 attached to the substrate 90 face the lower chamber 92 or the upper chamber 93. Two electrodes 900 are vertically aligned in the lower chamber 92. The upper electrode 900 is substantially rectangular. The lower electrode 900 is substantially trapezoidal. The substantially trapezoidal lower electrode 900 has a vertical length that is the shortest at the front end, gradually increases toward the rear, and is constant beyond a specific position. Three electrodes 900, which are each substantially rectangular, are aligned in the front-rear direction in the upper chamber 93.
The operation follower unit 7 and the switch follower unit 8, which are held by the holder 9 in a movable manner, are accommodated in the chamber 210 in the second half body 21 of the housing 2, which is sealed with a sealing method such as resin sealing.
The operation of the switch TS will now be described.
The operation of the switch TS in response to a depressing operation on the movable unit 1 will first be described.
The operation of the of the switch TS in response to a switching operation on the switch lever 3 will now be described.
When the switch lever 3 is between the positions shown in
When the switch lever 3 is between the positions shown in
An example configuration of the electric device ET incorporating the switch TS according to the embodiment of the present disclosure will now be described.
The operation detector TS1 is a circuit that detects a depressing operation on the movable unit 1 for driving the drive unit M. In the first embodiment, the operation detector TS1 includes a sensor that detects the capacitance of the capacitor formed with the operation follower unit 7 as a dielectric and various circuits. The operation detector TS1 detects a depressed amount of the movable unit 1 based on the capacitance between the two electrodes 900 in the lower chamber 92 on the substrate 90 and the conductive plates.
The switch detector TS2 is a circuit that detects a switching operation for swinging the switch lever 3. In the first embodiment, the switch detector TS2 includes a sensor that detects the capacitance of the capacitor formed with the switch follower unit 8 as a dielectric and various circuits. The switch detector TS2 detects the angle of the switch lever 3 based on the capacitance between the three electrodes 900 in the upper chamber 93 on the substrate 90 and the conductive plates.
The controller TS0 in the switch TS receives a detection result of the depressing operation from the operation detector TS1 and a detection result of the switching operation from the switch detector TS2. The controller TS0 determines an output of the drive unit M, such as the rotational speed of the motor, based on the detection result from the operation detector TS1. The controller TS0 determines a driving mode of the drive unit M, such as a rotation mode of the motor, based on the detection result from the switch detector TS2. The controller TS0 in the switch TS outputs, from the output unit TS3 to the main unit MU, an electric signal for driving the drive unit M with the driving mode determined based on the detection result from the switch detector TS2 and with the output based on the detection result from the operation detector TS1. The main unit MU drives the drive unit M in response to the electric signal input from the switch TS.
As described above, the drive unit M is driven in response to an operation on the switch TS.
In the second embodiment, the movements of the operation follower unit 7 and the switch follower unit 8 are detected based on the contact state of a mechanical contact unlike in the first embodiment in which the movements of the operation follower unit 7 and the switch follower unit 8 are detected contactlessly. In the second embodiment, like reference numerals denote like components in the first embodiment. The components in the first embodiment are to be referred to, and will not be described in detail. The appearance of a switch TS according to the second embodiment is substantially the same as in the first embodiment and will not be described in detail.
The internal structure of the switch TS will now be described.
The substrate 90 includes multiple thin plate-like fixed contacts 901 located to face the lower chamber 92 or the upper chamber 93. Two upper fixed contacts 901 aligned in the front-rear direction and two lower fixed contacts 901 aligned in the front-rear direction are attached to the lower chamber 92. In other words, four fixed contacts 901 aligned in the up-down direction and in the front-rear direction are attached to the lower chamber 92. Each fixed contact 901 is substantially rectangular. The lower rear fixed contact 901 is formed from a conductive material having lower conductivity than the conductive material for the other fixed contacts 901, and thus functions as a variable resistor having a resistance value that changes in accordance with a contact position. Three fixed contacts 901, which are each substantially rectangular, are aligned in the front-rear direction in the upper chamber 93.
The operation follower unit 7 includes a third magnet 70 and operation sliders 71 (sliders). The third magnet 70 is a substantially rectangular plate. Each operation slider 71 is a metal strip curved into a substantially bow shape. The third magnet 70 included in the operation follower unit 7 is located to have its magnetic poles positioned in the front-rear direction, for example, the north pole positioned frontward and the south pole positioned rearward. The operation follower unit 7 has recesses on its surface facing the substrate 90. The recesses receive the operation sliders 71. Each operation slider 71 in the operation follower unit 7 is a brush of a metal strip curved into a substantially bow shape. The operation slider 71 slides with its distal ends in contact with the fixed contact 901 on the substrate 90. The operation sliders 71 are aligned vertically and attached to the surface of the third magnet 70 facing the substrate 90.
The switch follower unit 8 includes a fourth magnet 80 and a switch slider 81. The fourth magnet 80 is a substantially rectangular plate. The switch slider 81 is a metal strip curved into a substantially bow shape. The fourth magnet 80 included in the switch follower unit 8 has a recess on its surface facing the substrate 90. The recess receives the switch slider 81. The switch slider 81 in the switch follower unit 8 is a brush of a metal strip curved into a substantially bow shape. The switch slider 81 slides with its distal ends in contact with the fixed contact 901 on the substrate 90. The switch slider 81 is attached to the surface of the fourth magnet 80 facing the substrate 90.
The operation of the switch TS will now be described.
The operation of the switch TS in response to a depressing operation on the movable unit 1 will first be described.
In a transmission mode in which the rotational speed of a drive unit M changes in accordance with the depressed amount of the movable unit 1, the drive unit M is driven in response to the lower rear operation slider 71 coming in contact with the lower rear fixed contact 901, and the rotational speed increases in accordance with the increase in the depressed amount. The lower rear fixed contact 901 functions as a variable resistor, thus allowing an operation detector TS1 to detect a resistance value to determine a depressed amount.
In a constant speed mode in which the rotational speed of the drive unit M is constant independently of the depressed amount of the movable unit 1, the drive unit M is driven in response to the upper rear operation slider 71 coming in contact with the upper rear fixed contact 901 and is controlled at a constant speed independently of the depressed amount.
The operation of the switch TS in response to a switching operation on the switch lever 3 will now be described.
The structure of an electric device ET in the second embodiment is substantially the same as the electric device ET in the first embodiment. Thus, the electric device ET in the first embodiment described with reference to
In the second embodiment, a switch detector TS2 detects the angle of the switch lever 3 based on the conductive state between the three fixed contacts 901 attached to the upper chamber 93 on the substrate 90.
A controller TS0 in the switch TS receives a detection result of the depressing operation from the operation detector TS1 and a detection result of the switching operation from the switch detector TS2. The controller TS0 determines an output of the drive unit M, such as the rotational speed of the motor, based on the detection result from the operation detector TS1. The controller TS0 determines a driving mode of the drive unit M, such as a rotation mode of the motor, based on the detection result from the switch detector TS2. The controller TS0 in the switch TS outputs, from the output unit TS3 to a main unit MU, an electric signal for driving the drive unit M with the driving mode determined based on the detection result from the switch detector TS2 and with the output based on the detection result from the operation detector TS1. The main unit MU drives the drive unit M in response to the electric signal input from the switch TS.
As described above, the switch TS according to one or more embodiments of the present disclosure separates components that operate in response to an operation for driving or switching from components associated with an electrical system that detect an operation and drive the drive unit M. The components associated with the electrical system spaced from the components that operate in response to an operation for driving or switching follow the components that operate in response to an operation for driving or switching with a magnetic force. The above described structure can easily achieve airtightness, or for example, can be waterproof or dustproof, and have higher airtightness. In particular, the components associated with the electrical system to detect an operation and drive the drive unit M are accommodated in the chamber 210 and are sealed hermetically to increase airtightness.
The components associated with the electrical system are accommodated in the chamber 210 and hermetically sealed, and are thus spaced from components that can easily lower airtightness, including components that change the inner volume of the housing 2, such as the movable unit 1, and components that extend, in operation, through the housing 2, such as the switch lever 3. The above-described structure can, for example, constantly maintain airtightness or have other advantageous effects, unlike, for example, a switch using a rubber gasket.
One or more embodiments is not limited to the above embodiments and may be modified in various manners. The above embodiments are mere examples and may not limit the disclosure. The technical scope is defined not by the description given above but by the claims. Any modifications and alterations contained in the equivalency range of the claims fall within the scope.
For example, although the operation-linked unit 4 and the operation follower unit 7 are both magnetic in the above embodiments, the present invention is not limited to the embodiments. For the operation-linked unit 4 and the operation follower unit 7 that follows the operation-linked unit 4, either of the operation-linked unit 4 or the operation follower unit 7 may be magnetic. The same applies to the switch-linked unit 5 and the switch follower unit 8.
For example, although the operation follower unit 7 and the switch follower unit 8 are formed from a magnetic and dielectric plastic magnetic material in the above embodiments, the present invention is not limited to the embodiments. The operation follower unit 7 and the switch follower unit 8 may be formed from any magnetic and dielectric material. For example, one or more embodiments may be variously modified to have, for example, the operation follower unit 7 and the switch follower unit 8 that are plate-like permanent magnets attached to resin plates.
For example, although the operation follower unit 7 and the switch follower unit 8 are formed using dielectrics to detect an operation contactlessly based on the capacitance in the above embodiments, the present invention is not limited to the embodiments. For example, the substrate 90 to which a magnetic sensor such as a Hall integrated circuit or an induction coil is attached may detect the movements of the magnetic operation follower unit 7 and the magnetic switch follower unit 8 contactlessly with the magnetic sensor. One or more embodiments may be variously modified to detect the movements of the magnetic operation follower unit 7 and the magnetic switch follower unit 8 contactlessly with, for example, an optical system such as a photoelectric sensor or an optical sensor.
For example, although the switch lever 3 is used to switch the driving mode by switching the rotational direction of the motor being the drive unit M between the forward rotation and the reverse rotation in the above embodiments, the present invention is not limited to the embodiments. The switch lever 3 may be used to switch any other driving mode. For example, one or more embodiments may be variously modified to include, for example, the switch lever 3 in the switch TS that switches between the transmission mode in which the output changes in accordance with the depressed amount of the movable unit 1 and the constant speed mode in which the output is constant independently of the depressed amount of the movable unit 1.
For example, although the operation detector TS1, the switch detector TS2, the controller TS0, and the output unit TS3 are located in the switch TS in the above embodiments, the present invention is not limited to the embodiments. The controller TS0 may be external to the housing 2 of the switch TS, or may be, for example, in the main unit MU.
For example, although one or more embodiments is applied to a trigger switch including a trigger in the above embodiments, the present invention is not limited to the embodiments. Any switch TS may include the movable unit 1 that moves in response to an operation. For example, one or more embodiments may be modified to be applicable to, for example, a push button switch including a push button as the movable unit 1. The switch TS according to one or more embodiments may be incorporated into not only a power tool but also other types of electric devices ET.
Number | Date | Country | Kind |
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2021-108913 | Jun 2021 | JP | national |