JP2021030343A - Angle tool - Google Patents

Abstract

To effectively prevent a tool body from being swung around.SOLUTION: A charging type angle drill 1 has: a brushless motor 6 having a rotor shaft 17; a spindle 8 which is rotated by the brushless motor 6 and orthogonal to the rotor shaft 17; and a housing 2 which houses the brushless motor 6 and supports the spindle 8. An acceleration sensor 57 for preventing swinging of the housing 2 around the spindle 8 is disposed at the housing 2, and swinging detection processing may be preformed by a controller 52.SELECTED DRAWING: Figure 2

Description

The present invention relates to an angle tool such as an angle drill having an output shaft orthogonal to the rotor shaft of the motor.

An angle tool such as an angle drill houses a motor in which the rotor shaft is directed in the front-rear direction in a housing that is a tool body. Further, a spindle (output shaft) orthogonal to the rotor shaft is projected downward from the front end of the housing (see, for example, Patent Document 1). A drill chuck to which a tip tool such as a drill bit can be attached is attached to the lower end of the spindle. Therefore, when the motor is driven and the rotor shaft is rotated, the spindle and the drill chuck are rotated, and the drill bit can be used to drill the work material.

Japanese Unexamined Patent Publication No. 2018-1361

In such an angle tool, if the tip tool suddenly bites into the work piece and is locked during work, the housing may be swung around the spindle.

An object of the present invention is to provide an angle tool capable of effectively preventing the housing from being swung around.

In order to achieve the above object, the invention according to claim 1 is an angle tool.
A motor with a rotor shaft and
An output shaft that is rotated by a motor and orthogonal to the rotor shaft,
Has a housing that houses the motor and supports the output shaft,
It is characterized in that an acceleration sensor is arranged in the housing to prevent swinging around the output shaft.
According to the second aspect of the present invention, in the above configuration, the housing extends in the front-rear direction and accommodates the motor in the center in the front-rear direction.
The output shaft extends downward from the front of the housing
The accelerometer is characterized in that it is located behind the motor.
According to the third aspect of the present invention, in the above configuration, the housing has a handle at the rear portion.
The accelerometer is characterized by being located at the rear of the steering wheel.
According to a fourth aspect of the present invention, in the above configuration, the housing has a handle at the rear portion.
The accelerometer is characterized in that it is located at the front of the steering wheel.
In the invention of claim 5, in the above configuration, the housing has a handle at the rear.
The handle has a vertical loop shape extending in the front-rear direction, and is characterized in that a grip portion is formed on an upper portion and an acceleration sensor is arranged on a lower portion.
According to the sixth aspect of the present invention, in the above configuration, a controller for controlling the motor is housed under the handle.
The acceleration sensor is characterized in that it is provided in the controller.
The invention according to claim 7 is characterized in that, in the above configuration, an intake port for cooling air for the motor is formed on the lower surface side of the controller under the handle.
The invention according to claim 8 is characterized in that, in the above configuration, a battery mounting portion on which a battery pack can be mounted is provided at the rear end of the housing.
The invention according to claim 9 is characterized in that, in the above configuration, two battery packs can be mounted vertically on the battery mounting portion.
In each invention, the "orthogonal" between the rotor shaft and the output shaft includes a strict orthogonality. Further, even in the orthogonal state with some error, if the housing is swung due to the lock of the output shaft, it is included.

According to the present invention, it is possible to effectively prevent the housing, which is the tool body, from being swung around.

It is a perspective view of the rechargeable angle drill. It is a central vertical sectional view of a rechargeable angle drill. It is a flowchart of a swinging detection process. It is a central vertical sectional view which shows the example of changing the arrangement of an acceleration sensor. It is a central vertical sectional view which shows the example of changing the arrangement of an acceleration sensor. It is a central vertical sectional view which shows the example of changing the arrangement of an acceleration sensor. It is a central vertical sectional view which shows the example of changing the arrangement of an acceleration sensor. It is the schematic of the angle drill which shows the example of changing the arrangement of an acceleration sensor.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view of a rechargeable angle drill which is an example of an angle tool. FIG. 2 is a central vertical sectional view of a rechargeable angle drill.
The rechargeable angle drill (hereinafter, simply referred to as “angle drill”) 1 includes a housing 2 that serves as a tool body. The housing 2 extends in the front-rear direction. The housing 2 includes a motor housing 3 arranged at the center in the front-rear direction, a gear housing 4 connected to the front side thereof, and a handle housing 5 connected to the rear side of the motor housing 3. The brushless motor 6 is housed in the motor housing 3. The reduction mechanism 7 is housed in the gear housing 4. The spindle 8 is housed downward in the gear housing 4 on the front side of the speed reduction mechanism 7. The lower end of the spindle 8 projects from the gear housing 4. A drill chuck 9 is fixed to the lower end of the spindle 8.

A front grip 10 is provided on the front portion of the gear housing 4. The front grip 10 is a grip portion whose upper end extends in the left-right direction. Both ends of the front grip 10 are connected to the left and right side surfaces of the gear housing 4. Screw holes 11 and 11 are provided on the left and right side surfaces of the gear housing 4 behind the front grip 10. A side grip (not shown) can be screwed into the screw hole 11.
The handle housing 5 is formed in a loop shape. A battery mounting portion 12 is integrally formed at the rear portion of the handle housing 5. Two upper and lower battery packs 13 and 13 can be attached to and detached from the battery mounting portion 12.
In FIGS. 1 and 2, the axial direction of the spindle 8 is the Z-axis direction, the left-right direction orthogonal to the Z-axis is the X-axis direction, and the front-rear direction and the Y-axis direction orthogonal to the Z-axis are defined.

The brushless motor 6 has a stator 15 and a rotor 16. The stator 15 has a tubular shape and is an inner rotor type in which the rotor 16 is arranged inside. The stator 15 is provided with a sensor circuit board 15a. The sensor circuit board 15a includes a rotation detection element that detects the magnetic field of the permanent magnet provided in the rotor 16. The rotor 16 has a rotor shaft 17 at the center of the shaft. The rotor shaft 17 extends in the front-rear direction and is supported by front and rear bearings 18, 18. A pinion 19 is formed at the tip of the rotor shaft 17. A fan 20 is attached to the rotor shaft 17 behind the bearing 18 on the front side. A plurality of exhaust ports 21, 21, ... Are formed in the motor housing 3 on the outside of the fan 20.
The speed reduction mechanism 7 includes a rear carrier 22 that supports a plurality of planetary gears 23, 23, ..., Each via a support pin 24. Further, it has a front carrier 25 that supports a plurality of planetary gears 26, 26, ..., Each via a support pin 27. Internal gears 28A and 28B are arranged outside the planetary gears 23 and 26, respectively. The planetary gear 23 of the rear carrier 22 meshes with the pinion 19 of the rotor shaft 17. A first intermediate shaft 29 is coupled to the axis of the rear carrier 22. The planetary gear 26 of the front carrier 25 meshes with the first intermediate shaft 29. A second intermediate shaft 30 having a bevel gear 31 at the front end is coupled to the front carrier 25. The second intermediate shaft 30 is coaxially supported by the bearing 32 with the first intermediate shaft 29.

The support pin 24 of the planetary gear 23, which is the first stage, penetrates the rear carrier 22 and projects forward. A ring-shaped switching member 33 is provided on the support pin 24 so as to be slidable back and forth. The switching member 33 is slidable to a retracted position in which it engages with the rear carrier 22 and the first intermediate shaft 29 and rotates integrally, and a forward position in which the switching member 33 is separated from the rear carrier 22. The front-rear position of the switching member 33 can be switched by rotating the speed switching lever 34 provided on the lower surface of the gear housing 4.
The support pin 27 of the planetary gear 26, which is the second stage, penetrates the planetary gear 26 and projects rearward. At the rear end of the support pin 27, an engaging member 35 with which the switching member 33 at the forward position engages in the rotational direction is provided.

Therefore, at the retracted position of the switching member 33, the rotation of the rear carrier 22 decelerated by the first-stage planetary gear 23 is transmitted to the second-stage planetary gear 26 via the first intermediate shaft 29. Then, the front carrier 25 is decelerated and rotated. Therefore, the second intermediate shaft 30 is decelerated in two stages and rotates at a low speed (first speed).
On the other hand, at the forward position of the switching member 33, the rotation of the rear carrier 22 decelerated by the first-stage planetary gear 23 is transmitted to the engaging member 35 via the support pin 24 and the switching member 33. Then, the front carrier 25 is directly rotated via the support pin 27. Therefore, the second intermediate shaft 30 is canceled at the second stage deceleration and rotates at high speed (second speed).

However, the internal gear 28B on the front side is rotatably provided in the gear housing 4. A holding ring 36 is screwed to the gear housing 4 in front of the internal gear 28B. A plurality of balls 37, 37, ... Are held in the holding ring 36 at equal intervals in the circumferential direction. A pressing body 38 and a coil spring 39 are arranged on the front side of each ball 37. Each coil spring 39 presses the ball 37 against the internal gear 28B via the pressing body 38. Therefore, the rotation of the internal gear 28B is restricted by the urging force of each coil spring 39. Then, when a torque exceeding the urging force is applied from the spindle 8 to the second intermediate shaft 30, the internal gear 28B idles and cuts off the rotation transmission to the spindle 8. That is, a torque limiter is formed.
On the other hand, the spindle 8 is located on the front axis of the second intermediate shaft 30. The spindle 8 is rotatably supported by upper and lower bearings 40, 40. A bevel gear 41 is integrally coupled to the spindle 8 above the second intermediate shaft 30. The bevel gear 41 meshes with the bevel gear 31 of the second intermediate shaft 30.

The handle housing 5 is formed by assembling the left and right half housings 5a and 5b with screws in the left and right directions. The handle housing 5 includes a tubular portion 45 connected to the rear end of the motor housing 3. Further, the handle housing 5 includes a grip portion 46 that vertically branches rearward from the tubular portion 45, and a controller housing portion 47. The grip portion 46 and the controller accommodating portion 47 are connected to each other to form a vertical loop shape, and are connected to the battery mounting portion 12.
The grip portion 46 has a tubular shape having a substantially circular cross section. A switch 48 having a trigger 49 protruding downward is housed on the front side of the grip portion 46. A forward / reverse switching lever 50 of the brushless motor 6 is provided in front of the switch 48. A main power switch 51 is provided on the upper surface of the tubular portion 45 in front of the switch 48.

The controller accommodating portion 47 has a tubular shape having a substantially quadrangular cross section. The controller accommodating portion 47 is formed to have a wider left-right width than the grip portion 46. The controller 52 is housed in the controller housing section 47. The controller 52 includes a control circuit board 53 having a rectangular shape in a plan view, and a case 54 for accommodating the control circuit board 53. The control circuit board 53 is equipped with a microcomputer, a switching element, or the like for driving the brushless motor 6. The controller 52 has a lateral posture in which the longitudinal direction extends in the front-rear direction and the lateral direction extends in the left-right direction.
A plurality of intake ports 55, 55 ... Are formed on the lower surface of the controller accommodating portion 47. Each intake port 55 is formed with an opening obliquely downward to the rear side.
A light 56 is provided in front of the controller 52. The light 56 includes an LED and is turned on by turning on the switch 48 by the trigger 49. By turning on the light 56, the front diagonally lower side below the drill chuck 9 is illuminated.

An acceleration sensor 57A is provided at the center of the battery mounting portion 12 in the vertical direction. The acceleration sensor 57A is electrically connected to the control circuit board 53 of the controller 52 by a lead wire (not shown). The acceleration sensor 57A includes a 3-axis acceleration sensor element that can be driven by electric power from the controller 52. This 3-axis acceleration sensor element is, for example, a MEMS (Micro Electro Mechanical System) type including a movable electrode portion and a detection electrode portion. Here, the movable electrode portion swings according to the acceleration applied from the outside, and the gap with the detection electrode portion changes. Then, the acceleration is detected based on the change in the capacitance generated between the two electrode portions according to the change in the gap. The detection signal is input to the control circuit board 53 of the controller 52.
The battery mounting portion 12 is formed with an opening rearward. Inside the battery mounting portion 12 (bottom side), two sideways terminal blocks 58, 58 are arranged side by side. The battery pack 13 is slid and mounted sideways from the left side on each terminal block 58.

In the angle drill 1 configured as described above, when the main power switch 51 is pressed and operated, the power from the battery pack 13 is supplied to the controller 52. When the trigger 49 is pushed in this state, the switch 48 is turned on. Then, the controller 52, which detects the rotation position of the rotor 16 on the sensor circuit board 15a, supplies power to the brushless motor 6 to rotate the rotor shaft 17. When the rotor shaft 17 rotates, the decelerated rotation is transmitted to the second intermediate shaft 30 via the speed reduction mechanism 7. Then, the spindle 8 decelerates and rotates via the bevel gears 31 and 41, and the drill chuck 9 is integrally rotated. Therefore, a tip tool such as a drill bit mounted on the drill chuck 9 can be used to drill a work material.

On the other hand, the rotor shaft 17 rotates and the fan 20 rotates integrally. Then, air is sucked from the intake port 55 provided on the lower surface of the handle housing 5. The sucked air reaches the motor housing 3 from the controller housing portion 47 through the tubular portion 45. Then, after passing through the brushless motor 6, the motor is discharged from the exhaust port 21. Due to this air flow, in the controller accommodating portion 47, the controller 52 is cooled by the air sucked from the lower surface side. Further, in the motor housing 3, the brushless motor 6 is cooled.

An acceleration detection circuit is formed on the control circuit board 53 of the controller 52. The acceleration detection circuit detects that the housing 2 has rotated by a predetermined angle or more about the spindle 8 based on the detection signal from the acceleration sensor 57A. Based on this detection, the controller 52 is swung around and can execute the detection process. That is, even if the rotation of the spindle 8 is unexpectedly locked due to the bite of the tip tool, the drive of the brushless motor 6 is stopped to prevent the housing 2 from being swung around the Z axis.
However, in the 1st speed in which the spindle 8 rotates at a low speed, the torque limiter works first due to the increase in the load torque accompanying the locking of the spindle 8. Therefore, the swing detection process functions at the second speed in which the spindle 8 rotates at high speed and the torque is small.
Hereinafter, this swing detection process will be described with reference to the flowchart of FIG.

First, when the switch 48 is turned on in S1 (S is a step, the same applies hereinafter), the controller 52 acquires acceleration in the X-axis direction by the acceleration sensor 57A in S2.
Next, in S3, the angular acceleration around the Z axis is calculated from the acquired acceleration in the X axis direction. This calculation is performed based on an arithmetic expression recorded in advance in a storage unit such as a ROM provided on the control circuit board 53.
Next, in S4, the calculated angular acceleration is integrated, and the angular velocity around the Z axis is calculated from the integrated value.
Next, in S5, the calculated angular velocity is integrated, and the rotation angle around the Z axis is calculated from the integrated value.

Next, in S6, based on the angular velocity obtained in S4, the rotation angle required for the brushless motor 6 to stop after detecting that the housing 2 has been swung around the Z axis is calculated.
Next, in S7, the predicted rotation angle around the Z axis is calculated by adding the rotation angle calculated in S6 to the rotation angle calculated in S5.
Next, in S8, it is determined whether or not the predicted rotation angle exceeds a threshold value preset in the storage unit. Here, when the threshold value is confirmed, it is determined in the next S9 whether or not a certain period of time or more has passed continuously since the threshold value was exceeded.
When it is confirmed in S9 that the time is longer than a certain period of time, the drive of the brushless motor 6 is stopped in S10. This prevents the housing 2 from being swung around due to the biting of the tip tool.
On the other hand, if the predicted rotation angle does not exceed the threshold value in the determination of S8, the process returns to S1. Further, even if the threshold value is exceeded in the determination of S8, the process returns to S1 when it is confirmed in the determination of S9 that the time is not longer than a certain period of time. If the switch 48 is in the ON state in S1, the swing detection process for acquiring the acceleration in the X-axis direction is performed again in S2.

As described above, the angle drill 1 of the above-described embodiment includes a brushless motor 6 (motor) having a rotor shaft 17. Further, a spindle 8 (output shaft) that is rotated by a brushless motor 6 and is orthogonal to the rotor shaft 17 is provided. Further, a housing 2 for accommodating the brushless motor 6 and supporting the spindle 8 is provided. Then, an acceleration sensor 57A for preventing swinging around the spindle 8 is arranged in the housing 2.
With these configurations, the controller 52, which is the control means of the brushless motor 6, is swung around to execute the detection process, and it is possible to effectively prevent the housing 2 from being swung around.

In particular, here, the housing 2 extends in the front-rear direction to accommodate the brushless motor 6 in the center of the front-rear direction, the spindle 8 extends downward from the front portion of the housing 2, and the acceleration sensor 57A is rearward of the brushless motor 6. Is placed in.
Further, the housing 2 has a handle housing 5 (handle) at the rear portion, and the acceleration sensor 57A is arranged at the rear portion of the handle housing 5.
With these configurations, the acceleration sensor 57A can be easily installed by utilizing the dead space in the housing 2.

The arrangement of the acceleration sensor is not limited to the above form. For example, in the case of FIG. 2, the handle housing 5 is not limited to the center of the rear portion, and may be closer to the upper side or the lower side.
Further, the acceleration sensor 57B may be arranged not only in the rear portion of the handle housing 5 but also in the tubular portion 45 in the front portion of the handle housing 5 as shown in FIG.
Even if the acceleration sensor 57B is arranged in the front portion of the handle housing 5 in this way, the dead space can be used.
Further, the acceleration sensor may be arranged in the controller housing portion 47 (lower portion) of the loop-shaped handle housing 5. In this case, the acceleration sensor may be mounted directly on the control circuit board 53 of the controller 52, or the control circuit board 53 and the acceleration sensor 57C may be connected via the lead wire 59 as shown in FIG. Good.
Even if the acceleration sensor 57C is arranged in the controller housing portion 47 in this way, the dead space can be used. Further, if the acceleration sensor 57C is provided in the controller 52, wiring is not required.

However, the arrangement of the acceleration sensor may be other than those shown in FIGS. 2 and 4 and 5. The type of acceleration sensor is not limited.
For example, as shown in FIG. 6, the controller 52 may be housed inside the grip portion 46. Then, the acceleration sensor 57D may be connected to the control circuit board 53 in the grip portion 46 via a lead wire. Further, the acceleration sensor 57D may be mounted directly on the control circuit board 53. In this case, the battery pack 13 may be one, and in other examples, the battery pack 13 may be one.
Further, as shown in FIG. 7, the controller 52 may be housed in the battery mounting portion 12. Then, the acceleration sensor 57E may be connected to the control circuit board 53 in the battery mounting portion 12 via a lead wire. Further, the acceleration sensor 57E may be mounted directly on the control circuit board 53. In this case, a switching element (FET or the like) that controls the current to the brushless motor 6 may be mounted on the sensor circuit board 15a. In this case, it is possible to suppress the heat generated by the switching element from being transmitted to the acceleration sensor 57E. Further, since it is the farthest point from the drill chuck 9, the detection accuracy of the acceleration sensor 57E can be improved. In another example, the switching element may be mounted on the sensor circuit board 15a.
Further, the present invention can be applied to an angle tool having a straight type grip portion (handle) such as the angle drill 1A shown in FIG. In this case, the acceleration sensor 57F is arranged behind the motor M. It may be inside or outside the controller 52.
The form of the angle drill does not have to have the speed switching function. The motor is not limited to brushless. It may be an AC machine that does not use a battery pack.

1,1A ... Rechargeable angle drill, 2 ... Housing, 3 ... Motor housing, 4 ... Gear housing, 5 ... Handle housing, 6 ... Brushless motor, 7 ... Reduction mechanism, 8 ... Spindle, 9 ... Drill chuck, 17 ... Rotor shaft, 48 ... Switch, 52 ... Controller, 53 ... Control circuit board, 57A to 57F ... Accelerometer.

Claims (9)

A motor with a rotor shaft and
An output shaft that is rotated by the motor and orthogonal to the rotor shaft,
It has a housing that houses the motor and supports the output shaft.
An angle tool in which an acceleration sensor is arranged in the housing to prevent swinging around the output shaft. The housing extends in the front-rear direction and houses the motor in the center in the front-rear direction.
The output shaft extends downward from the front of the housing.
The angle tool according to claim 1, wherein the acceleration sensor is arranged behind the motor. The housing has a handle at the rear and
The angle tool according to claim 2, wherein the acceleration sensor is arranged at the rear portion of the handle. The housing has a handle at the rear and
The angle tool according to claim 2, wherein the acceleration sensor is arranged at the front portion of the handle. The housing has a handle at the rear and
The angle tool according to claim 2, wherein the handle has a vertical loop shape extending in the front-rear direction, a grip portion is formed in an upper portion, and the acceleration sensor is arranged in a lower portion. A controller for controlling the motor is housed under the handle.
The angle tool according to claim 5, wherein the acceleration sensor is provided in the controller. The angle tool according to claim 6, wherein an intake port for cooling air of the motor is formed on the lower side of the handle and on the lower surface side of the controller. The angle tool according to any one of claims 1 to 7, wherein a battery mounting portion to which a battery pack can be mounted is provided at the rear end of the housing. The angle tool according to claim 8, wherein two battery packs can be mounted vertically on the battery mounting portion.

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