Power tool
AssigneeMakita Corporation
InventorYonosuke Aoki
Life of this patent
Estimating the term…
Abstract
Provided is a power tool which is capable of more reliably detecting excessive reaction torque acting on a tool body. More specifically, provided is a handheld power tool which causes a tip tool to rotate so as to carry out a predetermined machining operation, the handheld power tool comprising a tool body, a motor which is housed in the tool body and causes the tip tool to rotate, a first sensor which detects the torque state of the tip tool, a second sensor which detects the motion state of the tool body, and a torque cut-off mechanism which cuts off the transmission of torque between the motor and the tip tool. The torque cut-off mechanism is configured to cut off the transmission of torque on the condition that the first sensor and the second sensor respectively detect a preset threshold value for the first sensor and the second sensor.
Claims13
A hand-held power tool, which performs a predetermined operation by rotationally driving a tool bit, comprising:
- a tool body,
- a tool holder that holds the tool bit,
- a motor that is housed in the tool body and rotationally drives the tool bit,
- a first intermediate shaft which is connected to an output shaft of the motor, the first intermediate shaft being driven by the motor and transmitting torque,
- a second intermediate shaft which is disposed between the tool holder and the first intermediate shaft, the second intermediate shaft receiving the torque from the first intermediate shaft and transmitting the torque to the tool holder;
- a first sensor that detects torque applied on the second intermediate shaft,
- a second sensor that detects motion of the tool body,
- a torque transmission interrupting mechanism that can interrupt torque transmission between the first intermediate shaft and the second intermediate shaft, and
- a mechanical limiter that is disposed on the second intermediate shaft and is capable of interrupting the torque transmission between the motor and the tool bit,
- wherein the torque transmission interrupting mechanism interrupts torque transmission between the first intermediate shaft and the second intermediate shaft, when both the torque detected by the first sensor and the motion of the tool body detected by the second sensor reach respective preset threshold,
- the torque transmission interrupting mechanism does not interrupt the torque transmission between the first intermediate shaft and the second intermediate shaft, when at least one of the torque detected by the first sensor and the motion of the tool body detected by the second sensor does not reach corresponding preset threshold, and
- the mechanical limiter interrupts the torque transmission between the motor and the tool bit when the torque detected by the first sensor reaches a preset another threshold, which is different from the preset threshold, the mechanical limiter interrupting the torque transmission independently from a detection result of the second sensor.
A hand-held power tool, which performs a predetermined operation by rotationally and linearly driving a tool bit, comprising:
- a tool body,
- a motor that is housed in the tool body and rotationally drives the tool bit,
- an impact drive mechanism that is driven by the motor and linearly drives the tool bit,
- a rotary drive mechanism that is driven by the motor and rotationally drives the tool bit,
- a first sensor that detects torque of the tool bit,
- a second sensor that detects motion of the tool body,
- an electromagnetic clutch mechanism that is disposed in a rotary drive path and can interrupt transmission of the torque for rotationally driving the tool bit between the motor and the tool bit, and
- a controller that controls the electromagnetic clutch mechanism based on a detection result of the first sensor and a detection result of the second sensor,
- wherein the controller controls the electromagnetic clutch mechanism such that when both the torque detected by the first sensor and the motion of the tool body detected by the second sensor reach respective preset threshold, the electromagnetic clutch mechanism interrupts the transmission of the torque in the rotary drive path while a linearly driving of the tool bit by the impact drive mechanism is maintained.
A hand-held power tool, which performs a predetermined operation by rotationally driving a tool bit, comprising:
- a tool body,
- a tool holder that holds the tool bit,
- a motor that is housed in the tool body and rotationally drives the tool bit,
- an intermediate shaft which is disposed between the tool holder and the motor, the intermediate shaft being driven by the motor and transmitting torque to the tool holder,
- a first sensor that detects torque applied on the intermediate shaft,
- a second sensor that detects motion of the tool body,
- a torque transmission interrupting mechanism that can interrupt torque transmission between the motor and the tool bit, and
- a mechanical limiter that is disposed on the intermediate shaft and is capable of interrupting the torque transmission between the motor and the tool bit,
- wherein the torque transmission interrupting mechanism interrupts torque transmission, when both the torque detected by the first sensor and the motion of the tool body detected by the second sensor reach respective preset threshold,
- the torque transmission between the motor and the tool bit is maintained when at least one of the torque detected by the first sensor and the motion of the tool body detected by the second sensor does not reach corresponding preset threshold, and
- the mechanical limiter interrupts the torque transmission between the motor and the tool bit when the torque detected by the first sensor reaches a preset another threshold, which is greater than the preset threshold, the mechanical limiter interrupting the torque transmission independently from a detection result of the second sensor.
Dependencies are inferred from the claim text.