CN210173433U

CN210173433U - Screw fastening tool

Info

Publication number: CN210173433U
Application number: CN201921117550.6U
Authority: CN
Inventors: Masashi Ito; 伊藤雅; Akihiro Hara; 原彰宏
Original assignee: Makita Corp
Current assignee: Makita Corp
Priority date: 2018-09-20
Filing date: 2019-07-17
Publication date: 2020-03-24
Anticipated expiration: 2029-07-17
Also published as: JP2020044627A; JP7300251B2; DE202019105112U1

Abstract

The utility model relates to a screw fastening instrument, it can be easily and reliably carry out visual confirmation to the luminous part for the notice. A charging type right-angle screw driver (1) comprises: a brushless motor (4); a clutch (6) which is disposed in front of the brushless motor (4) and which connects and disconnects rotation from the brushless motor (4); and an output shaft (12) which is disposed in front of the clutch (6) and which transmits rotation from the clutch (6) so that screw tightening can be achieved by the output shaft (12), wherein a notification light emitting unit (75) which notifies of the screw tightening is disposed in front of the brushless motor (4).

Description

Screw fastening tool

Technical Field

The utility model relates to a screw fastening instrument such as right angle screw driver.

Background

In a screw tightening tool such as a right-angle screw driver, a notification light emitting unit for notifying an operator of information relating to screw tightening, such as completion of tightening and attachment of a bolt or the like with a predetermined torque or occurrence of an error, may be provided. For example, patent document 1 discloses an invention in which a motor is housed and includes a main body portion extending in a front-rear direction, and a handle portion connected to the main body portion and extending downward, and a notification light emitting portion (LED) is provided at least up to a side surface from a rear surface of the main body portion.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2018-94651

SUMMERY OF THE UTILITY MODEL

In the screw fastening tool of patent document 1, the LED as the notification light emitting unit is provided up to the side surface of the main body, and therefore, the visual confirmation is higher than that in the case where the LED is only on the rear surface. However, in general, in the screw fastening work, the worker's attention is focused on the screw fastening portion at the front end of the main body, and therefore, even on the side surface of the main body, there is a possibility that the LED located on the rear side is overlooked or the LED does not enter the visual field.

Therefore, the present invention provides a screw fastening tool capable of visually confirming the notification light emitting portion easily and reliably.

In order to achieve the above object, the utility model described in claim 1 relates to a screw fastening tool, which includes: a motor; a clutch disposed in front of the motor and configured to connect and disconnect rotation from the motor; and an output shaft that is disposed in front of the clutch, transmits rotation from the clutch, and enables screw tightening through the output shaft, wherein a notification light-emitting unit that notifies of the screw tightening is disposed in front of the motor.

A utility model relating to claim 2 is characterized in that, in addition to the configuration described in claim 1, the notification light emitting unit is disposed further forward than the clutch.

A feature of the invention according to claim 3 is that, in addition to the configuration described in claim 1 or 2, the motor is disposed such that the rotation axis faces forward, and the output shaft is disposed orthogonal to the rotation axis.

A feature of the invention according to claim 4 is that, in addition to the configuration described in claim 1 or 2, the motor is disposed such that the rotation axis faces forward, and the output shaft is disposed coaxially with or parallel to the rotation axis.

A feature of a utility model relating to claim 5 is that, in addition to the configuration described in any one of claims 1 to 4, the screw tightening tool has a tubular front side housing that holds the clutch and/or the output shaft and extends forward, and the notification light emitting portion is disposed on an outer surface of the front side housing in a rotation stop state.

A utility model according to claim 6 is characterized in that, in addition to the configuration described in claim 5, the notification light emitting unit includes: a circuit board disposed in a posture orthogonal to the front case; a plurality of LEDs arranged on the front surface of the circuit board; and a lens disposed in front of the LED.

A utility model according to claim 7 is characterized in that, in addition to the configuration described in claim 6, the circuit board is in a U-shape when viewed from the front.

A feature of the invention according to claim 8 is that, in addition to the configuration described in claim 7, the circuit board is inserted and fitted into the outer surface of the front case from the outside in the radial direction of the front case.

A feature of the invention according to claim 9 is that, in addition to the configuration described in any one of claims 6 to 8, the LEDs are arranged at least within 240 ° in the circumferential direction of the front side case.

A feature of the utility model according to claim 10 is that, in addition to the configuration described in claim 9, the circuit board is provided so as to surround the entire circumference of the shaft of the front side case.

In order to achieve the above object, the invention described in claim 11 relates to a screw fastening tool including: a motor; a clutch disposed in front of the motor and configured to connect and disconnect rotation from the motor; and an output shaft disposed in front of the clutch, transmitting rotation from the clutch, and enabling screw tightening through the output shaft, wherein a light emitting portion for notification of the screw tightening is provided forward.

According to the present invention, since the notification light-emitting portion is close to the screw-fastening portion, the notification light-emitting portion can be easily viewed even if the attention of the operator is focused on the screw-fastening portion.

Drawings

Fig. 1 is a side view of a charging type right-angle screw driver.

Fig. 2 is a bottom view of the rechargeable right-angle screw driver.

Fig. 3 is a front enlarged view of the charging type right-angle screw driver.

Fig. 4 is a central longitudinal sectional view of the charging type right-angle screw driver.

Fig. 5 is an enlarged view of the front portion of fig. 4.

Fig. 6 is a perspective view illustrating the front case and the notification light emitting portion in an exploded manner.

Fig. 7(a), 7(B), and 7(C) are explanatory views of the circuit board, with fig. 7(a) showing a front view, 7(B) showing a rear view, and 7(C) showing a perspective view from the rear surface.

Fig. 8 is an enlarged cross-sectional view of the circuit board at the position of the inclined surface portion of the tab showing the insertion and fitting state.

Fig. 9 is a schematic view of a charging type screw driver according to a modification.

Description of the reference numerals

A rechargeable right-angle screw driver, a 1a.. rechargeable screw driver, a 2.. main body, a 3.. motor housing, a 4.. brushless motor, a 5.. clutch housing, a 6.. clutch, a 7.. handle housing, a 8.. battery mounting portion, a 10.. front side housing, a 11.. output portion, a 12.. output shaft, a 13.. battery pack, a 15.. controller, a 16.. control circuit board, a 26.. rotation shaft, a 45.. rear cam, a 47.. front cam, a 48.. spindle, a 52.. coil spring, a 62.. sensor board, a 65.. magnet, a 66.. detection board, a 67.. hall IC, a 68.. window, a 69.. lighting board, a 70.. lighting board, a 75. notification circuit board, a 75.. light-emitting portion, a light-emitting portion, and a light-emitting portion, 77..

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings.

Fig. 1 is a side view, fig. 2 is a bottom view, fig. 3 is a front view, and fig. 4 is a central longitudinal sectional view of a rechargeable right-angle screw driver (hereinafter simply referred to as "screw driver") 1 as an example of a screw fastening tool.

The main body 2 of the screw driver 1 is formed into a cylindrical body extending linearly in the front-rear direction, and includes: a motor housing 3 that houses the brushless motor 4 at the center in the front-rear direction; a clutch housing 5 connected to the front side of the motor housing 3, accommodating the clutch 6, and extending forward; a handle case 7 connected to the rear side of the motor case 3 and extending rearward; and a battery mounting portion 8 coupled to the rear side of the handle case 7. The main body 2 is formed by assembling left and

right split cases

2a, 2b with

screws

9, 9.

A front case 10, which is housed in the output portion 11 and extends forward in a side view in an inverted L shape, is coupled to the front end of the main body portion 2, and an output shaft 12 is projected downward.

On the other hand, a battery pack 13 as a power source is slidably attached to the battery mounting portion 8 from below, and a terminal block 14 electrically connected to the battery pack 13 attached is provided in the battery mounting portion 8. On the front side of the terminal block 14, a controller 15 in which a control circuit board 16 on which a capacitor, a microcomputer, a switching element, and the like are mounted is housed in a case 17 is provided in parallel with the terminal block 14.

Further, a trigger switch 18 for projecting a trigger 19 downward is housed in a front portion of the handle case 7 in front of the terminal block 14. A forward/reverse switching button 20 of the brushless motor 4 is provided in front of the trigger switch 18.

The brushless motor 4 is an inner rotor type having a stator 21 and a rotor 22, and the stator 21 has: a stator core 23;

insulators

24 and 24 provided in front and rear of the stator core 23; and a plurality of

coils

25, 25 wound around the stator core 23 via

insulators

24, 24. Further, the rotor 22 includes: a rotating shaft 26 located at the axial center; a cylindrical rotor core 27 disposed around the rotating shaft 26;

permanent magnets

28, 28 disposed outside the rotor core 27 in a cylindrical shape such that polarities alternately change in the circumferential direction; and a plurality of permanent magnets 29, 29 for sensors, which are arranged in a radial shape on the front side of the

permanent magnets

28, 28. A sensor circuit board 30 is screwed to the front end of the front insulator 24 from the front, and a rotation detection element, not shown, that detects the position of the sensor permanent magnet 29 and outputs a rotation detection signal is mounted on the sensor circuit board 30. The signal line 31 of the rotation detection element is led out rearward from the lower side of the sensor circuit board 30 and wired to the control circuit board 16. The magnet wires of the respective phases forming the three-phase coil 25 are electrically connected to the terminal unit 32 screwed to the lower side of the front insulator 24 via the fuse terminal, and the power supply line led out rearward from the terminal unit 32 behind the signal line 31 is wired to the control circuit board 16.

Inside the main body portion 2, a front wall 33 that partitions between the motor housing 3 and the clutch housing 5 and a rear rib 34 that partitions between the motor housing 3 and the handle housing 7 are provided. The rotary shaft 26 is rotatably supported in the front-rear direction by a bearing 36 held by a cylindrical bearing holder 35 received by the front wall 33 and a bearing 37 held at the center of the rear rib 34. A centrifugal fan 38 for cooling the motor is fixed to the front of the bearing 37 of the rotary shaft 26, a plurality of

air inlets

39, 39 are formed at a radially outer portion of the stator 21 of the motor housing 3, and a plurality of

air outlets

40, 40 are formed at a radially outer portion of the centrifugal fan 38.

The rotary shaft 26 has a bearing holder 35 inserted therein and projecting forward, and a pinion gear 41 fixed to a front end thereof. A speed reduction mechanism including front and rear two-

stage carriers

43 and 43 supporting a plurality of

planetary gears

44 and 44 in an internal gear 42 is disposed in front of the bearing holder 35, and the pinion gear 41 meshes with the

planetary gears

44 and 44 of the rear carrier 43.

The clutch 6 includes a rear cam 45 that rotates integrally with the front carrier 43, and a front cam 47 that engages with the rear cam 45 in the rotational direction via a cam ball 46. A main shaft 48 penetrates the center of the clutch 6, and the main shaft 48 is coupled to the front cam 47 in the rotational direction via a ball 50 provided in a cam groove 49. A coil spring 52 is provided between a spring seat 51 through which the main shaft 48 passes and the front cam 47 in front of the front cam 47, and biases the front cam 47, which is movable forward and backward with respect to the main shaft 48 via a ball 50, to a retracted position where the front cam is engaged with the cam ball 46. The main shaft 48 is provided at the rear end of the front housing 10 and coaxially protrudes inside a small-diameter cylindrical joint 53 held at the front end of the clutch housing 5. A screw portion 54 protruding forward of the clutch housing 5 is formed in a front portion of the joint 53.

The front housing 10 has a joint 53 and an inverted L-shaped elbow 55 provided in front of the joint 53, and the front housing 10 and the clutch housing 5 are coupled by screwing a threaded sleeve 56 fitted around the rear end of the elbow 55 into the outer periphery of the threaded portion 54 of the joint 53.

In the front side housing 10, an intermediate shaft 57 having a bevel gear 58 at its front end is held by a plurality of

bearings

59 and 59 at the rear end of the intermediate joint 53 and the elbow 55, and the hexagonal rear end (fig. 6) of the intermediate shaft 57 projecting rearward is fitted into a hexagonal hole formed at the front end of the main shaft 48 and is integrally coupled in the rotational direction.

Further, at the downward tip end portion of the elbow 55, the output shaft 12 is held by upper and

lower bearings

60, 60 and projects downward, and a bevel gear 61 provided on the output shaft 12 is engaged with a bevel gear 58 of the intermediate shaft 57.

Therefore, in the clutch 6, if the rear cam 45 rotates together with the front carrier 43 that rotates from the rotary shaft 26 through two-stage speed reduction, the front cam 47 rotates via the cam ball 46, and the main shaft 48 rotates via the ball 50 (rotational connection by the clutch 6). Then, the intermediate shaft 57 integral with the main shaft 48 rotates, and the output shaft 12 rotates via the bevel gears 58 and 61.

On the other hand, if the load torque transmitted from the output shaft 12 to the main shaft 48 via the intermediate shaft 57 exceeds the pressing force (set torque) of the front cam 47 determined by the coil spring 52, the front cam 47 advances via the balls 50 rolling in the cam groove 49, and the engagement with the cam ball 46 is released and the rear cam 45 idles (the rotation by the clutch 6 is disconnected).

As shown in fig. 5, the sensor plate 62 is provided below the clutch 6 so as to be movable forward and backward and biased to the retreated position by a coil spring 63, and an engaging piece 64 projecting toward the spindle 48 side is positioned in front of the front cam 47. Therefore, when the clutch 6 is rotated and disengaged, the front cam 47 advances and comes into contact with the engagement piece 64, and the sensor plate 62 advances integrally with the front cam 47. A magnet 65 is provided at the rear of the sensor plate 62, and a detection substrate 66 having a hall IC 67 on the lower surface thereof is provided in the front-rear direction, and is connected to the control circuit board 16 via a lead wire, not shown, below the magnet. That is, when the clutch 6 is operated and the sensor plate 62 moves forward, the hall IC 67 detects a change in the magnetic field of the magnet 65 moving forward, and the detection substrate 66 transmits a detection signal thereof to the control circuit substrate 16.

Further, a rectangular window 68, which is long in the front-rear direction, is formed on the lower surface of the clutch housing 5 in front of the sensor plate 62, and an illumination substrate 69, on which 2

illumination lamps

70, 70 composed of LEDs are arranged in the front-rear direction, is provided in the window 68 in an inclined posture toward the oblique front. A cover 71 for covering the lighting board 69 from below is provided on the lower side of the lighting board 69, and the cover 71 is fitted to the window 68 from the inside to expose the lower surface parallel to the lighting board 69. Therefore, the vicinity of the output shaft 12 can be reliably illuminated.

In addition, a notification light emitting unit 75 for notifying whether or not the screw tightening is acceptable is provided at the front end of the clutch housing 5 in front of the clutch 6. As shown in fig. 5 and 6, the notification light emitting unit 75 is composed of a circuit board 76 on which 3

notification lamps

77 and 77 are mounted along the front surface, and a lens 78 which is assembled in front of the circuit board 76. As shown in fig. 7(a), 7(B), and 7(C), the circuit board 76 is formed into a U shape in front view by a radial slit 79 passing through the center, and the lamps 77 are arranged one by one at intervals of 120 ° in the circumferential direction at both sides of the slit 79 and at the center portion on the tip side of the slit 79, and are arranged at the apexes of a regular triangle. In each

lamp

77, 2 LEDs of green and red are provided. A connection portion 80 of a lead is provided on the rear surface of the circuit board 76.

On the other hand, a pair of

inclined surface portions

81, 81 matching the width of the notch 79 of the circuit board 76 are formed in a rear portion of the screw portion 54 of the joint 53 in a direction inclined by 45 ° with respect to the vertical direction in front view. Therefore, the circuit board 76 can be inserted and fitted into the rear portion of the threaded portion 54 obliquely from below or obliquely from above along the

inclined surfaces

81 and 81. A ridge 82 having the same outer diameter as the circuit board 76 protrudes concentrically from the outer side of the threaded portion 54 on the front end surface of the clutch housing 5.

The lens 78 is formed of a light-transmitting white resin, has an annular outer diameter substantially equal to the diameter of the front end of the clutch housing 5, and has an outer peripheral rear end fitted over the convex strip 82 of the clutch housing 5 to accommodate the circuit board 76 on the rear surface. A tapered surface 83 whose tip is tapered toward the front is formed on the side surface of the lens 78 over the entire circumference, and an annular concave groove 84 into which the

lamps

77 and 77 of the circuit board 76 are fitted is formed on the rear surface.

On the other hand, an O-ring 85 is externally attached between the screw portion 54 of the joint 53 and the

inclined surface portions

81 and 81, and in a state where the lens 78 is externally fitted to the front end surface of the clutch housing 5, the O-ring 85 abuts against the inner peripheral side of the front surface of the lens 78 to prevent the lens 78 from coming off.

Therefore, when the notification light emitting portion 75 is assembled to the front end surface of the clutch housing 5, the circuit board 76 is inserted and fitted into the

inclined surface portions

81 and 81 from diagonally left and downward in the direction of the notch 79 and positioned at the front end of the convex strip 82 before the elbow 55 is connected to the joint 53, as shown in fig. 8. Thus, the lamps 77 are uniformly arranged on the circumference centering on the axis of the main shaft 48 and positioned at the vertices of the regular triangle.

Next, the notification light emitting unit 75 can be assembled by covering the lens 78 from the front of the circuit board 76 and fitting it into the convex strip 82, and fitting the O-ring 85 around the screw portion 54. Here, the rear end portion of the elbow 55 is assembled to the joint 53 with the phase in the rotational direction being aligned by the positioning pins 86, 86 provided on the front surface of the joint 53, and if the threaded sleeve 56 is screwed into the threaded portion 54, the elbow 55 and the joint 53 are coupled. At this time, the rear end of the threaded sleeve 56 approaches the inner periphery of the lens 78 of the light emitting section 75 for notification, and the lens 78 is also prevented from coming off here. The lead wires connected to the connection portion 80 of the circuit board 76 and the lead wires connected to the detection board 66 and the illumination board 69 are led through the wiring space 87 (fig. 4 and 5) formed below the sensor board 62 and the detection board 66 and led rearward along the lower inner surface of the clutch housing 5, and are led through the inside of the handle housing 7 and electrically connected to the control circuit board 16.

In the screw driver 1 configured as described above, if the driver head attached to the output shaft 12 is pressed against the screw to be fastened, and the trigger 19 is pushed in this state to turn on the trigger switch 18, power is supplied from the battery pack 13 to drive the brushless motor 4. That is, the microcomputer of the control circuit board 16 acquires the rotation detection signal indicating the position of the sensor permanent magnet 29 of the rotor 22 output from the rotation detection element of the sensor circuit board 30 to acquire the rotation state of the rotor 22, controls ON/OFF of each switching element according to the acquired rotation state, and sequentially causes current to flow through each coil 25 of the stator 21 to rotate the rotor 22. However, the operation amount (pressing amount) of the trigger 19 is transmitted to the microcomputer as a signal, and the rotation of the rotor 22 is controlled in accordance with the operation amount.

When the rotor 22 rotates in this manner, the rotation shaft 26 rotates to rotate the

planetary carriers

43 and 43 at a reduced speed via the planetary gear 44, and the main shaft 48, the intermediate shaft 57, and the output shaft 12 are rotated via the clutch 6. Thus, the screw fastening can be achieved by the driver bit. If the screw tightening progresses to reach the set torque determined by the coil spring 52, the front cam 47 advances, and the transmission of rotation from the rear cam 45 is disconnected in the clutch 6 as described above, and the rotation of the output shaft 12 stops.

At this time, when the detection board 66 detects the advance of the sensor plate 62 based on the operation of the clutch 6 while the microcomputer of the control circuit board 16 is pressing the trigger 19, it is determined that the screw fastening is "acceptable", and the light emitting unit 75 for notification causes the lights 77 of the circuit board 76 to emit light of green color. On the other hand, when the detection substrate 66 does not detect the advance of the sensor plate 62 (for example, when the pushing operation of the trigger 19 is stopped before the advance of the sensor plate 62 is detected), it is determined that the screw fastening is "failed", and the lamps 77 of the circuit substrate 76 are caused to emit red light.

In this way, in the notification light emitting portion 75, the entire lens 78 emits green or red light by the light emission of the 3

lamps

77 and 77 that are immediately behind the bend 55, and thus the light appears over the entire circumference of the front end surface and the front end of the clutch housing 5. Therefore, the operator can naturally visually confirm the light emission from the lens 78 from all directions at the position close to the screw fastening portion without moving the line of sight regardless of the orientation of the screw driver 1, and can easily confirm the determination result.

On the other hand, the notification light-emitting unit 75 is used for notification of a decrease in the remaining capacity of the battery pack 13 (flashing red or the like), notification of an abnormal decrease in the voltage supplied to the controller 15 (alternately lighting red and green or the like), notification of an abnormal temperature of the controller 15 (flashing red or the like), and the like, in addition to notification of whether or not the screw fastening is acceptable.

Further, if the centrifugal fan 38 rotates together with the rotary shaft 26, the air sucked through the air inlet 39 cools the brushless motor 4 and is discharged through the air outlet 40.

Further, the trigger switch 18 is turned on and the

lighting lamps

70 and 70 of the lighting substrate 69 are turned on by the control circuit board 16. Therefore, the front of the screwdriver bit is irradiated through the cover 71, and the workability can be maintained even in a dark place.

As described above, according to the screw driver 1 of the above-described aspect, since the notification light emitting unit 75 that notifies about screw fastening is disposed in front of the brushless motor 4, the notification light emitting unit 75 is located closer to the screw fastening portion, and even if the attention of the operator is focused on the screw fastening portion, the operator can easily enter the field of view, and can easily and reliably visually confirm the notification light emitting unit 75.

In particular, since the notification light emitting unit 75 is disposed forward of the clutch 6, the notification light emitting unit 75 is further disposed toward the screw fastening portion, and the visual confirmation is further improved.

Further, since the front side case 10 having a cylindrical shape that holds the output shaft 12 and extends forward is provided and the notification light emitting unit 75 is disposed on the outer surface of the front side case 10 in a rotation stop state, the notification light emitting unit 75 can be assembled at an appropriate position in the circumferential direction of the front side case 10.

The notification light emitting unit 75 is configured to include: a circuit board 76 disposed in a posture orthogonal to the front case 10; a plurality of LEDs (lamps 77) disposed on the front surface of the circuit board 76; and a lens 78 disposed in front of the lamp 77, so that the notification light emitting unit 75 suitable for emitting light to the front and the outer periphery can be obtained.

Since the circuit board 76 has a U-shape when viewed from the front, the front case 10 can be easily assembled.

Further, since the circuit board 76 is inserted and fitted into the outer surface of the front case 10 from the outside in the radial direction of the front case 10, erroneous assembly of the circuit board 76 does not occur.

Further, since the lamps 77 are arranged within 240 ° in the circumferential direction of the front side case 10, an effective light emission state is achieved.

In particular, in the screw driver 1 of the above-described aspect, the notification light emitting unit 75 is disposed forward, and therefore the visual confirmation is improved.

On the other hand, the screw driver 1 according to the above aspect includes: a motor (brushless motor 4) having a rotating shaft 26; a clutch 6 disposed in front of the brushless motor 4, for connecting and disconnecting rotation from the brushless motor 4; an output shaft 12 disposed in front of the clutch 6 so as to be orthogonal to the rotation shaft 26 and transmitting rotation from the clutch 6; a motor case 3 that houses the brushless motor 4; a handle case 7 disposed behind the motor case 3 and extending in the front-rear direction; and a battery mounting portion 8 which is disposed behind the handle case 7 and which can be screwed by the output shaft 12, and a notification light emitting portion 75 which gives notification about screwing is disposed in front of the brushless motor 4, and therefore the notification light emitting portion 75 is disposed close to the screw fastening portion, and visual confirmation can be easily and reliably performed.

The front side case of the above-described aspect holds the output shaft and the intermediate shaft, but may extend rearward to further hold the clutch. On the contrary, the arrangement of the light emitting unit for notification can be realized even if only the clutch is held without holding the output shaft.

In addition, the notification light emitting unit may be configured such that the circuit board is inserted and fitted from obliquely upper left side, or may be configured such that the circuit board is not limited to a U shape in front view, but may be semicircular or arc-shaped in front view depending on the number of lamps. As long as the front side case can be externally fitted, a ring shape around the entire circumference of the shaft of the front side case, including the circuit board and the lens, may be used. However, the outer shape of the notification light emitting unit is not limited to a ring shape, and may be a square or polygonal shape as long as it is in front of the motor. The number and the interval in the circumferential direction of the lamps are not limited to the above-described embodiments, and the lamps may be arranged in a range exceeding 240 ° in the circumferential direction by appropriately increasing or decreasing.

On the other hand, the notification light emitting unit is not limited to the configuration including the circuit board and the Lamp (LED), and for example, a strip-shaped LED in which LEDs are mounted on a flexible strip-shaped resin substrate at a constant interval may be used, and the strip-shaped LED may be wound around the outer periphery of the front side case, or a strip-shaped LED of a different color may be cut at an appropriate length and disposed on the outer surface of the front side case.

Further, the notification light-emitting portion may be formed by winding an EL fiber, which is obtained by forming the inorganic EL light-emitting material into a cylindrical shape, into a ring shape in a groove provided on the outer periphery of the front case. In this case, in order to realize multicolor, it is necessary to wind a plurality of EL fibers having different colors.

The notification light emitting unit of the present invention including the above-described embodiments and modifications is not limited to being disposed in front of the clutch, and may be disposed between the motor and the clutch.

In addition, the present invention is not limited to a right-angle screw driver, and can be applied to other screw fastening tools such as a screw driver in which an output shaft is not output in a shape orthogonal to a main shaft. Therefore, the main body portion is not limited to a straight line, and the present invention can be applied to a so-called T-shaped (gun-shaped) screw fastening tool in which the handle case 7 and the motor case 3 are coupled to each other in an orthogonal manner, as in the rechargeable screw driver 1A schematically shown in fig. 9. Here, the main shaft 48 protrudes forward from the clutch housing 5 coaxially with the rotary shaft 26 as an output shaft, and a notification light emitting unit 75 is provided at the front end of the clutch housing 5. However, the main shaft 48 may be not coaxial but parallel to the rotation shaft 26.

The present invention is not limited to DC tools using a battery pack as a power source, and can be applied to AC tools using a commercial power source. The motor may be other than a brushless motor, such as a commutator motor.

Further, the effect of improving the visual confirmation obtained by disposing the notification light emitting portion in the vicinity of the working portion such as the screw fastening portion can be obtained also in other electric tools such as a hammer drill in addition to the screw fastening tool, and therefore, a configuration can be obtained in which the notification light emitting portion is disposed at the front end of the main body portion and the front side housing of the electric tool.

Claims

1. A screw fastening tool having:

a motor;

a clutch disposed in front of the motor and configured to connect and disconnect rotation from the motor; and

an output shaft disposed in front of the clutch and transmitting rotation from the clutch,

screw fastening can be achieved by means of the output shaft,

the method is characterized in that:

the notification light emitting unit that notifies of the screw tightening is disposed forward of the motor.

2. The screw tightening tool according to claim 1,

the notification light emitting unit is disposed forward of the clutch.

3. The screw tightening tool according to claim 1 or 2,

the motor is disposed such that a rotation axis faces forward, and the output shaft is disposed orthogonal to the rotation axis.

4. The screw tightening tool according to claim 1 or 2,

the motor is arranged such that a rotation shaft faces forward, and the output shaft is arranged coaxially with or parallel to the rotation shaft.

5. The screw tightening tool according to claim 1 or 2,

the screw tightening tool includes a cylindrical front case that holds the clutch and/or the output shaft and extends forward, and the notification light emitting unit is disposed on an outer surface of the front case in a rotation stop state.

6. The screw tightening tool according to claim 5,

the notification light emitting unit includes: a circuit board disposed in a posture orthogonal to the front side case; a plurality of LEDs arranged on the front surface of the circuit board; and a lens disposed in front of the LED.

7. The screw tightening tool according to claim 6,

the circuit substrate is in a U shape when being observed from the front side.

8. The screw tightening tool according to claim 7,

the circuit board is inserted and fitted into an outer surface of the front case from a radially outer side of the front case.

9. The screw tightening tool according to claim 6,

the LEDs are arranged at least in the range of 240 degrees in the circumferential direction of the front side shell.

10. The screw tightening tool according to claim 9,

the circuit substrate is disposed around the entire circumference of the shaft of the front side case.

11. A screw fastening tool having:

a motor;

screw fastening can be achieved by means of the output shaft,

it is characterized in that the preparation method is characterized in that,

the notification light emitting unit for performing notification related to the screw tightening is provided facing forward.