WO2016084742A1

WO2016084742A1 - Impact tool and method for manufacturing spindle for impact tool

Info

Publication number: WO2016084742A1
Application number: PCT/JP2015/082728
Authority: WO
Inventors: 信一浦野; 鈴木　康之; 規生遠藤
Original assignee: 株式会社マキタ
Priority date: 2014-11-25
Filing date: 2015-11-20
Publication date: 2016-06-02
Also published as: JP2016097487A; CN107107316A

Abstract

The present invention easily makes machining of a spindle possible even when a spindle with an integrated carrier section is used and limits increased cost. An impact wrench (1) is provided with: a brushless motor (8); a spindle (63) that rotates as a result of being driven by the brushless motor (8) and comprises an integrated carrier section (64) for holding support pins (80) of a planetary gear (65) at both the front and back ends in the axial direction thereof; and an impact mechanism (10) capable of applying on an anvil (4) a rotary impact force resulting from rotation of the spindle (63). The spindle (63) is divided into three parts, a front spindle (66), a back spindle (67), and joining pins (68) with the accommodating space for the planetary gear (65) in the carrier section (64) as boundaries, and is formed by joining the respective parts to each other.

Description

Impact tool and impact tool spindle manufacturing method

The present invention relates to an impact tool such as an impact driver and an impact wrench, and a method of manufacturing a spindle for the impact tool.

An impact tool such as an impact driver includes an anvil having a spindle that rotates as the motor is driven, a hammer that is cam-coupled to the spindle, and a striking mechanism that includes a coil spring that biases the hammer, and the hammer serves as a final output shaft. When the torque of the anvil increases, the rotation of the spindle can be converted into an intermittent rotational striking force (impact) of the hammer by the striking mechanism and applied to the anvil (for example, see Patent Document 1). ).
The spindle used here is integrally provided with a carrier portion that supports both support shafts of a plurality of planetary gears by front and rear disks, and is coaxial with the rotation shaft by meshing the rotation shaft of the motor at the center of the planetary gear. The arrangement is known.

JP 2014-167926 A

In the conventional impact tool described above, since the carrier part is formed integrally with the spindle, it is necessary to process the engraving space for the planetary gear while leaving the coupling part of the front and rear disk parts in the carrier part. It takes a lot of time and effort, leading to an increase in cost.

Accordingly, an object of the present invention is to provide an impact tool and a method for manufacturing an impact tool spindle that can be easily processed and can suppress an increase in cost even if a spindle having an integrated carrier portion is used. .

In order to achieve the above object, the invention according to claim 1 is an impact tool, which is a motor and a carrier part that rotates by driving the motor and holds the support shaft of the planetary gear at both front and rear ends in the axial direction. And a striking mechanism capable of imparting a rotational striking force to the final output shaft as the spindle rotates, and the spindle is front and rear in the axial direction with the planetary gear housing space in the carrier as a boundary. It is divided into at least two parts and formed by joining the parts.
According to a second aspect of the present invention, in the configuration of the first aspect, the spindle includes a front spindle integrally including a front carrier plate that holds the front end of the support shaft, and a rear carrier plate that holds the rear end of the support shaft. It is divided into three parts including a rear spindle provided integrally and a joining member for joining the front carrier plate and the rear carrier plate.
According to a third aspect of the present invention, in the configuration of the second aspect, the joining member is a two-stage diameter joining pin having a small-diameter portion projecting coaxially at both ends, and the front-side small-diameter portion is the front carrier plate. It is characterized by being inserted and joined in the provided front through hole, and inserted and joined in the rear through hole provided in the rear carrier plate with the small diameter portion on the rear side.
The invention according to claim 4 is the configuration of claim 3, wherein the joining of the small diameter portion on the front side and the front through hole is by brazing, and the position of the front through hole on the rear surface of the front carrier plate is as follows: A circular recess for brazing is formed concentrically.
According to a fifth aspect of the present invention, in the configuration of the third or fourth aspect, the joining of the rear small diameter portion and the rear through-hole is by brazing, and the rear through-hole is opened on the rear surface of the rear carrier plate. At this time, the taper portion for brazing is formed so as to expand rearward.
According to a sixth aspect of the present invention, in the configuration of the third aspect, the joining of the front small-diameter portion and the front through-hole and the joining of the rear small-diameter portion and the rear through-hole are performed in each through-hole of each small-diameter portion. It is characterized by press-fitting into.
In order to achieve the above object, the invention according to claim 7 is a method of manufacturing a spindle for an impact tool integrally having a carrier portion for holding a supporting shaft of a planetary gear at both front and rear ends in the axial direction. The spindle is divided into at least two parts before and after the axial direction with the planetary gear housing space in the carrier portion as a boundary, and each part is individually manufactured, and the manufactured parts are joined and assembled.
According to an eighth aspect of the present invention, in the configuration of the seventh aspect, the support hole of the support shaft is processed after joining the parts.

According to the first and seventh aspects of the invention, the spindle is divided into at least two parts in the planetary gear housing space, and each part is joined and formed, so that the spindle has an integrated carrier portion. However, processing can be easily performed, and cost increase can be suppressed.
According to the second aspect of the present invention, in addition to the effect of the first aspect, by dividing the spindle into three parts, that is, the front spindle, the rear spindle, and the joining member, it is possible to obtain a form of parts that can be easily processed.
According to the eighth aspect of the invention, in addition to the effect of the seventh aspect, the accuracy of the support hole can be ensured by processing the support hole of the support shaft after joining the components.

It is a longitudinal cross-sectional view of an impact wrench. It is an expanded vertical sectional view of a main-body part. It is the perspective view which looked at the stator from back. It is explanatory drawing of a spindle, (A) is a rear view, (B) is a longitudinal cross-sectional view, (C) is the A section enlarged view. It is explanatory drawing of a front spindle, (A) is a perspective view, (B) is a rear view, (C) is a longitudinal cross-sectional view. It is explanatory drawing of a rear spindle, (A) is a perspective view, (B) is a rear view, (C) is a longitudinal cross-sectional view. It is explanatory drawing of a joining pin, (A) is a perspective view, (B) is a side view. It is explanatory drawing of the example of a change of a spindle, (A) is a rear view, (B) is a longitudinal cross-sectional view, (C) is the A section enlarged view. It is explanatory drawing of a front spindle, (A) is a rear view, (B) is a longitudinal cross-sectional view.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view of an impact wrench which is an example of an impact tool. The impact wrench 1 has a T-shape in which a handle 3 is formed downward on a main body 2 extending in the front-rear direction. An anvil 4 serving as a final output shaft protrudes from the front end of the main body 2 and is provided at the lower end of the handle 3. A battery pack 6 serving as a power source is attached to the mounting portion 5.
The housing of the main body 2 includes a synthetic resin main body housing 7 with a handle 3 extending in the rear part for accommodating the brushless motor 8, and a metal hammer case assembled in front of the main body housing 7 to accommodate the striking mechanism 10. Nine. The main body housing 7 is formed by assembling a pair of left and right

half housings

7a, 7b with

screws

11, 11,.

A metal gear housing 12 fitted to the rear end of the hammer case 9 is held behind the hammer case 9 in the main body housing 7. Here, the rib 13 provided on the outer periphery of the gear housing 12 is sandwiched between the main body housing 7 and the hammer case 9, and a bolt (not shown) is screwed from the rear so that the main body housing 7, the gear housing 12, and the hammer case 9 is integrated. By screwing the bolt into the metal hammer case 9 in this manner, the main body housing 7, the hammer case 9, and the gear housing 12 are firmly coupled, and the durability is improved. Moreover, since the main body housing 7 is formed by the

half housings

7a and 7b, wiring can be easily performed.

A switch 14 with a trigger 15 projecting forward and a motor forward / reverse switching button 16 are provided on the upper portion of the handle 3, while the lower mounting portion 5 is held by a dish-like case 18 and is brushless. A control circuit board 17 on which a switching element for controlling the motor 8 and a microcomputer are mounted is accommodated. The control circuit board 17 is provided with a switch panel 19 having a hitting force switching button, a battery remaining capacity display lamp, and the like, and is exposed through a window 20 provided in front of the mounting portion 5. The lower part of the handle 3 and the mounting part 5 are connected by assembling the left and

right halves

5a and 5b forming the mounting part 5 to the connecting part 21 protruding from the lower end of the handle 3 and fixing them with

screws

22 and 22. Is done. An elastic member 23 is interposed between the connecting portion 21 and the mounting portion 5 so as to be able to mitigate the impact and vibration transmitted from the handle 3 to the mounting portion 5. The battery pack 6 has a structure in which the rails are coupled to each other by sliding from the front with respect to the mounting portion 5, and the terminal plate of the terminal block 24 provided on the mounting portion 5 together with the connection is a terminal on the battery pack 5 side And electrically connected.

The brushless motor 8 accommodated in the rear part of the main body housing 7 is an inner rotor type composed of a stator 25 and a rotor 26 inside thereof, as shown in FIG. The stator 25 includes a cylindrical stator core 27 formed of a plurality of laminated steel plates, a front insulator 28 and a rear insulator 29 provided on front and rear end surfaces in the axial direction of the stator core 27, and the stator core 27 via the front and

rear insulators

28 and 29. 6

coils

30, 30... A sensor circuit board 31 and a short-circuit member 32 are attached to the rear insulator 29.

The rear insulator 29 is a ring-shaped integral product having the same diameter as the stator core 27. As shown in FIG. 3, the rear insulator 29 has six

holding portions

33, 33,. Yes. The holding portion 33 is formed by arranging a pair of

protrusions

34 and 34 having grooves at predetermined intervals so that the grooves face each other. A screw boss (not shown) protrudes between the holding

portions

33 and 33. It is installed.
In addition, a pair of recesses 35 are formed on the left and right sides of the rear insulator 29, and a pair of triangular

first notches

36, 36 are provided on the upper and lower sides across the

recesses

35, 35. Are formed respectively. Furthermore, a square-shaped second notch 37 is formed at the upper center of the rear insulator 29.

A fusing terminal 38 is held in each holding portion 33 of the rear insulator 29. The fusing terminal 38 is formed by folding a band-shaped metal fitting in half, and a bent portion 40 that is bent in a convex shape is formed at an intermediate portion at one end. Therefore, when the bent side of each fusing terminal 38 is inserted into the holding portion 33 and both side edges are fitted into the grooves of the

projections

34, 34, the fusing terminals 38 are concentrically arranged with the bent portion 40 outward. The other end 39 is held parallel to the axial direction of the rear insulator 29 with the posture facing the inside.
The coil 30 is wound around the teeth of the stator core 27 by one winding in order, and each winding 30a connecting between the

coils

30 and 30 wraps around the outside of the holding portion 33 to bend the fusing terminal 38. By being sandwiched between the portions 40, each fusing terminal 38 is electrically connected.

The sensor circuit board 31 includes three rotation detection elements (not shown) that detect the position of the permanent magnet 54 provided on the rotor 26 and output a rotation detection signal, and have an outer diameter that fits inside the holding portion 33. Four

protrusions

41, 41... That are donut-shaped and have outer perforations corresponding to the screw bosses of the rear insulator 29 are extended on the outer periphery. It is positioned on the rear surface of the insulator 29. The signal line 42 of the rotation detection element is drawn from the lower part of the sensor circuit board 31.

The short-circuit member 32 is a resin ring having substantially the same diameter as the sensor circuit board 31, and four

bosses

43, 43,... Into which the screw bosses of the rear insulator 29 can be fitted from the rear are integrated on the outer periphery. It protrudes to. The short-circuit member 32 includes an arc-shaped sheet metal member 44 having a pair of short-

circuit pieces

44A and 44A projecting diagonally, an arc-shaped sheet metal member 45 also having the short-

circuit pieces

45A and 45A, and a short-circuit piece. The arc-shaped sheet metal member 46 provided with 46A and 46A is insert-molded in a state of being superimposed on a concentric circle in a non-contact state. The short-

circuit pieces

44A, 45A, and 46A project radially from the short-circuit members 44 to 46 and correspond to the fusing terminals 38. At the tip, there are slits 47 into which the other end portions 39 of the fusing terminals 38 can be inserted. Each is formed. The U-phase, V-phase, and W-

phase power lines

48, 48,... Are welded to the sheet metal members 44 to 46, respectively.

When this short-circuit member 32 is overlapped from the rear of the sensor circuit board 31 and fixed with

screws

49, 49... So that the screw boss of the rear insulator 29 is inserted into the boss 43, the other end 39 of each fusing terminal 38 is Respectively inserted into the slits 47 of the corresponding short-circuit pieces 44A to 46A. If the fusing terminal 38 and the short-circuit pieces 44A to 46A are soldered in this state, the

fusing terminals

38 and 38 positioned symmetrically with respect to the point are short-circuited by the sheet metal members 44 to 46, respectively. That is, the fusing terminal 38 electrically connected to the winding 30a between the

coils

30 and 30 wound in order on the stator core 27 is electrically connected diagonally to each other by the three sheet metal members 44 to 46. Therefore, it becomes a so-called para-winding delta connection.

Here, since the sensor circuit board 31 and the short-circuit member 32 are accommodated within the height dimension of the fusing terminal 38, the total length of the brushless motor 8 can be minimized even if the short-circuit member 32 or the like is used. Further, since all members except the signal line 42 and the power supply line 48 are accommodated in the outer diameter of the stator core 27, the outer diameter of the product is not increased and the product becomes compact.
The stator 25 assembled in this manner is held at the outer periphery by supporting

ribs

50 and 50 projecting in the circumferential direction on the inner surfaces of the

half housings

7a and 7b of the main body housing 7 and also projects on the inner surfaces of the

half housings

7a and 7b. The projections (not shown) provided are respectively fitted in the recesses 35 formed on the side surface of the rear insulator 29, so that they are accommodated in a state of being positioned in the axial direction and the circumferential direction. In addition, when accommodating the 1st notch part 36 and the 2nd notch part 37 in the cylindrical housing used for a maroon etc., it can utilize for positioning by fitting the rib provided in the cylindrical housing. Here, a positioning recess 51 is also formed on the outer periphery of the front insulator 28.

On the other hand, the rotor 26 is fixed around the rotating shaft 52 positioned at the shaft center, the substantially cylindrical rotor core 53 that is arranged around the rotating shaft 52 and is formed by laminating a plurality of steel plates, and the rotor core 53. Have two plate-like permanent magnets (sintered magnets) 54, 54. The permanent magnets 54 are inserted into through holes 55 formed so as to be located on four sides of a square centering on the rotation shaft 52 in the cross section of the rotor core 53 and fixed by an adhesive and / or press-fitting.
The rear end of the rotary shaft 52 is pivotally supported by a bearing 56 held at the rear portion of the main body housing 7, and the front end is pivotally supported by a bearing 57 held by the gear housing 12, so that the front end where the pinion 58 is formed is formed. Projecting forward of the gear housing 12. A centrifugal fan 59 is attached to the rear portion of the bearing 57 on the rotating shaft 52. 60, 60... Are exhaust ports formed on the left and right side surfaces of the main body housing 7 at the position of the centrifugal fan 59, and the intake ports are provided on the rear surface of the main body housing 7 (not shown).

Further, in the rotor 26, a front stopper 61 is provided between the rotor core 53 and the centrifugal fan 59. The front stopper 61 is a disc made of brass and having the same outer diameter as the rotor core 53, and is fixed to the rotating shaft 52 coaxially with the rotor core 53. On the other hand, a rear stopper 62 is provided on the inner side of the sensor circuit board 31 between the rotor core 53 and the rear bearing 56. The stopper 62 is a disc made of brass and having an outer diameter smaller than that of the rotor core 53. The stopper 62 is coaxial with the rotor core 53 and is fixed to the rotating shaft 52 with a gap between the rotor core 53 and the stopper 62. However, the outer diameter of the rear stopper 62 is larger than the inner circle surrounded by the four permanent magnets 54, and the rear stopper 62 is positioned behind each permanent magnet 54.

The spindle 63 and the striking mechanism 10 are accommodated in a space surrounded by the hammer case 9 and the gear housing 12. First, the spindle 63 integrally has a carrier portion 64 that holds three

planetary gears

65, 65,... In the rear portion. Here, as shown in FIG. The front spindle 66 and the rear spindle 67 are joined by three joining

pins

68, 68,.
First, as shown in FIG. 5, the front spindle 66 has a disk-like front carrier plate 69 at the rear end, and has a shaft shape with a small-diameter insertion portion 70 protruding from the front end. A bottomed hole 71 opening rearward is formed, and a pair of V-shaped

cam grooves

72, 72 are formed on the front outer peripheral surface. Three front through-

holes

73, 73... Are formed on the front carrier plate 69 at equal intervals in the circumferential direction on the rear surface of the front carrier plate 69. The circular recess 74 for brazing the joining pin 68 is concentrically provided. A thick step 75 is formed at the base of the front spindle 66 where the front carrier plate 69 is formed. The front through hole 73 is open outside the stepped portion 75.

As shown in FIG. 6, the rear spindle 67 has a cylindrical shape with a disc-shaped rear carrier plate 76 formed at the front end. The rear spindle 67 is located near the outer periphery of the rear carrier plate 76 and is the same as the front through hole 73 of the front carrier plate 69. Three rear through-

holes

77, 77... Having a diameter are formed on a concentric circle having the same size as the front through-hole 73 at equal intervals in the circumferential direction. When each rear through-hole 77 is opened on the rear surface of the rear carrier plate 76, a taper portion 78 for brazing the joining pin 68 is formed so as to expand rearward.
The joining pin 68 is a shaft body having a diameter smaller than the diameter of the circular recess 74 provided in the front carrier plate 69. As shown in FIG. 7, the joint pin 68 has a two-stage diameter in which small-

diameter portions

79 and 79 are coaxially projected at both ends. It has become. The small diameter portion 79 has a diameter that can be inserted into the front and rear through

holes

73 and 77 of the front and

rear carrier plates

69 and 76.

The spindle 63 is manufactured as follows.
After processing the front spindle 66, the rear spindle 67, and the joining pin 68 individually, the front small-diameter portion 79 of each joining pin 68 is made into the front through hole 73 of the front carrier plate 69, and the rear small-diameter portion 79 is made into the rear carrier. The front spindle 66 and the rear spindle 67 are temporarily joined by being inserted into the rear through holes 77 of the plate 76, respectively. Next, solder (for example, copper solder) is put in the circular recess 74 around the joining pin 68 on the rear surface of the front carrier plate 69 and melted to braze the front carrier plate 69 and the joining pin 68, and the rear carrier plate. The rear carrier plate 76 and the small-diameter portion 79 are brazed by soldering and melting the tapered portion 78 of the rear through-hole 77 on the rear surface of the rear surface 76. Then, the front carrier plate 69 of the front spindle 66 and the rear carrier plate 76 of the rear spindle 67 are joined together via the three joining pins 68.

Next, as shown in FIG. 4, the front carrier plate 69 and the rear carrier plate 76 are concentrically overlapped with the step 75 of the front spindle 66 on the inner side of the front and rear through

holes

73 and 77 and back and forth in the circumferential direction. Support holes 81, 81... For inserting and supporting support pins 80 as support shafts that penetrate the three planetary gears 65 are respectively inserted from the rear of the rear carrier plate 76 at positions between the through

holes

73 and 77. Drill. Thus, since the support hole 81 is processed after joining the front spindle 66 and the rear spindle 67, the accuracy of the support hole 81 can be ensured.
Finally, with the planetary gear 65 positioned between the front carrier plate 69 and the rear carrier plate 76, the support pin 80 is inserted from the rear of the rear carrier plate 69 to the rear support hole 81, the planetary gear 65, the front side. If the support holes 81 are passed through in this order, the spindle 63 in which the planetary gear 65 is supported by the carrier portion 64 in a both-sided state is obtained.

In the hammer case 9, the spindle 63 is pivotally supported by a bearing 82 held at the rear end of the rear spindle 67 by the gear housing 12, and the planetary gear 65 meshes with an internal gear 83 held by the gear housing 12 in front of the spindle 63. To do. And the insertion part 70 of a front end is coaxially inserted in the insertion hole 84 provided in the axial center of the anvil 4, and is supported so that it can rotate coaxially with the rotating shaft 52. In this state, the pinion 58 of the rotating shaft 52 is inserted into the bottomed hole 71 from behind and meshes with each planetary gear 65 at the center of the three planetary gears 65.

The striking mechanism 10 includes a hammer 85 mounted on the front portion of the spindle 63,

balls

86 and 86 provided between the hammer 85 and the spindle 63, and a coil spring 87 that biases the hammer 85 forward. The The hammer 85 has a pair of claws (not shown) on the front surface, and can be engaged with a pair of

arms

88 and 88 provided at the rear end of the anvil 4 in the rotational direction. A pair of protruding

chevron grooves

89 and 89 are formed, and a ring groove 90 is formed coaxially on the rear surface. The

balls

86 and 86 are fitted over the cam groove 72 of the spindle 63 and the chevron groove 89 of the hammer 85 to integrate the spindle 63 and the hammer 85 in the rotational direction. Relative rotation and back-and-forth movement of the hammer 85 are allowed in the rolling range of the ball 86 with respect to. The coil spring 87 is externally mounted on the spindle 63 so that the front end is inserted into the ring groove 90 of the hammer 85, while the rear end is brought into contact with the front surface of the rear carrier plate 69 outside the stepped portion 75. The ball 86 is urged to the forward movement position of FIGS. 1 and 2 located at the center of the rear end of the angle groove 89 and the center of the front end of the cam groove 72. 91 and 92 are balls and washers which are provided at the bottom of the ring groove 90 and receive the front end of the coil spring 87.

The anvil 4 is pivotally supported coaxially with the spindle 63 by a bearing metal 94 held by a bearing portion 93 provided at the front end of the hammer case 9, and a regulating ring 95 provided between the bearing portion 93 and the

arms

88, 88. Is positioned forward. A grease reservoir 96 extending forward to the inside of the bearing metal 94 is extended in the insertion hole 84 into which the insertion portion 70 of the spindle 63 is inserted, and a ring groove 97 provided on the outer periphery of the grease reservoir 96 and the anvil 4. Is connected to the ring groove 97 through the communication hole 98 so that the bearing metal 94 and the anvil 4 are lubricated. Yes. A seal ring 99 is provided between the bearing portion 93 and the anvil 4 in front of the bearing metal 94, and a socket 100 can be attached to and detached from the front end of the anvil 4.

In the impact wrench 1 configured as described above, when the trigger 15 is pushed in, the switch 14 is turned on and the brushless motor 8 is driven by the power supply of the battery pack 6. That is, the microcomputer of the control circuit board 17 obtains the rotation detection signal indicating the position of the permanent magnet 54 of the rotor 26 output from the rotation detection element of the sensor circuit board 31, acquires the rotation state of the rotor 26, and acquires the obtained rotation. The ON / OFF of each switching element is controlled according to the state, and the rotor 26 is rotated by causing a current to flow sequentially to each coil 30 of the stator 25. Therefore, the rotation of the rotating shaft 52 and the planetary gear 65 of the carrier portion 64 planetarily moves, so that the reduced rotation is transmitted to the spindle 63, and the hammer 85 is rotated via the

balls

86, 86. The mating anvil 4 rotates and the socket 100 can be tightened with a bolt or the like.

When tightening proceeds and the torque of the anvil 4 increases, the hammer 85 moves backward while rolling the ball 86 along the cam groove 72 against the bias of the coil spring 87. When the claw is disengaged from the

arms

88, 88, the hammer 85 moves forward by rotating the ball 86 forward along the cam groove 72 by the bias of the coil spring 87, and the claw is re-engaged with the

arms

88, 88. In combination, a rotational impact force (impact) is generated on the anvil 4. Further tightening is performed by intermittently repeating this impact.
On the other hand, since the rotating rotor 26 is provided with a front stopper 61 and a rear stopper 62 on the front and rear, the movement of each permanent magnet 54 in the front-rear direction is restricted, and it is prevented from coming out of the through hole 55 of the rotor core 53. Is done. Therefore, there is no possibility that the permanent magnet 54 will fall off, and the highly reliable brushless motor 8 can be used.

As described above, according to the impact wrench 1 and the manufacturing method of the spindle 63 for the impact wrench 1 described above, the spindle 63 is divided into three parts (front and rear) in the axial direction with the housing space for the planetary gear 65 in the carrier portion 64 as a boundary. It is divided into a spindle 66, a rear spindle 67, and a joining pin 68), and each part is joined and formed, so that even the spindle 63 having the carrier portion 64 can be easily processed. Cost increase can be suppressed.
In particular, here, the spindle 63 is divided into three parts, that is, a front spindle 66, a rear spindle 67, and a joining pin 68, so that a form of parts that can be easily processed is obtained.

In the above embodiment, the front spindle 66 and the rear spindle 67 and the joining pin 68 are joined by brazing, but they may be joined by press-fitting the joining pin 68. FIGS. 8 and 9 show an example. In this spindle 63, the front spindle 66A is not provided with a circular recess for brazing on the rear surface of the front carrier plate 69 as in the previous embodiment, and only the front through hole 73 is provided. Is provided. In other words, the small diameter portion 79 on the front side of the joining pin 68 is press-fitted into the front through hole 73, while the small diameter portion 79 on the rear side is pressed into the rear through hole 77 of the rear carrier plate 76 of the rear spindle 67 to join. is there.
If the joining is performed by press-fitting in this way, the processing step of the circular concave portion and the brazing step in the front spindle 66A become unnecessary, and further cost reduction can be expected. Here, the rear carrier plate 76 has the same structure as that of the previous embodiment, and both the case of brazing and the case of press-fitting are possible. However, if only the press-fitting is performed, the taper portion 78 of the rear through-hole 77 is eliminated. This makes it possible to further reduce processing steps.

On the other hand, in the above embodiment, the spindle is divided into three parts: a front spindle, a rear spindle, and a joining pin. However, the joining pin is integrally formed on one of the front spindle and the rear spindle to form two parts (two parts). The spindle can be assembled by joining the joining pin to the other side by brazing or press fitting. Also, the joining pin is divided into front and rear, the front part of the joining pin is formed integrally with the front spindle, and the rear part of the joining pin is formed integrally with the rear spindle to be divided into two parts (two parts). It is also possible to assemble the spindle by joining the rear part by brazing or press fitting. Of course, the joining member is not limited to a shaft body such as a joining pin, and a wall body or the like may be employed. Further, the support hole is not limited to processing after assembling of each component, but may be processed at the time of manufacturing each component depending on the division form.

And in the said form, although the joining pin which joins a front spindle and a rear spindle, and the support pin of a planetary gear are separated, the joining pin is eliminated and the support shaft of a planetary gear is made into the joining member of a front spindle and a rear spindle. Can also be used.
Further, the number of planetary gears is not limited to three, and two planetary gears may be used. However, a carrier unit having three or more planetary gears is more effective in reducing costs.
In addition, an impact tool in which the motor is not brushless, an impact tool using an AC power source, or the like may be used. The impact tool is not limited to a wrench, and a spindle that integrally has a carrier portion that supports both ends of a planetary gear support shaft is used. If it is a thing, even if it is an angle impact wrench which provided the anvil at right angle with respect to the spindle, an impact driver, etc., this invention is employable. The present invention can also be applied to electric tools (for example, a driver drill, a shear wrench, etc.) using other planetary gears.

1 ・・ Impact wrench 2 ・・ Main body 3 ・・ Handle 4 ・・ Anvil 5 ・・ Mounting part 6 ・・ Battery pack 7 ・・ Main body housing 8 ・・ Brushless motor 9 ・・ Hammer case 10 .. Strike mechanism, 25 .. Stator, 26 .. Rotor, 31 .. Sensor circuit board, 32 .. Short circuit member, 52 .. Rotating shaft, 63 .. Spindle, 64. Planetary gear, 66 ·· Front spindle, 67 · · Rear spindle, 68 · · Joint pin, 69 · · Front carrier plate, 73 · · Front through hole, 74 · · Circular recess, · · · Rear carrier plate, · -Rear through hole, 78-Tapered part, 79-Small diameter part, 80-Support pin, 81-Support hole, 85-Hammer, 86-Ball, 87-Coil spring, 100-Socket

Claims

An impact tool,
A motor,
A spindle that integrally rotates with a carrier portion that rotates by driving the motor and holds the support shaft of the planetary gear at both front and rear ends in the axial direction;
A striking mechanism capable of imparting a rotational striking force to the final output shaft as the spindle rotates,
The impact tool, wherein the spindle is divided into at least two parts before and after the planetary gear in the carrier portion and is formed by joining the parts.
The spindle includes a front spindle integrally including a front carrier plate for holding a front end of the support shaft, a rear spindle integrally including a rear carrier plate for holding a rear end of the support shaft, and the front carrier plate. The impact tool according to claim 1, wherein the impact tool is divided into three parts including a joining member that joins the rear carrier plate.
The joining member is a two-stage joining pin having coaxially projecting small-diameter portions at both ends, and is joined by inserting the front-side small-diameter portion into a front through hole provided in the front carrier plate, The impact tool according to claim 2, wherein the small diameter portion on the side is inserted and joined to a rear through hole provided in the rear carrier plate.
The joining of the small diameter portion on the front side and the front through hole is by brazing, and a circular concave portion for brazing is formed concentrically at the position of the front through hole on the rear surface of the front carrier plate. The impact tool according to claim 3, wherein the impact tool is provided.
The small diameter portion on the rear side and the rear through hole are joined by brazing, and when the rear through hole is opened on the rear surface of the rear carrier plate, a taper portion for brazing expands rearward. The impact tool according to claim 3 or 4, wherein the impact tool is formed in an open shape.
The joining of the small diameter part on the front side and the front through hole and the joining of the small diameter part on the rear side and the rear through hole are performed by press-fitting the small diameter part into the through holes. Item 4. The impact tool according to Item 3.
A method for manufacturing a spindle for an impact tool that integrally has a carrier portion for holding a planetary gear support shaft at both axial front and rear ends,
The spindle is divided into at least two parts before and after in the axial direction with the receiving space for the planetary gear in the carrier section as a boundary, and each part is individually manufactured, and the manufactured parts are joined and assembled. A manufacturing method of a spindle for impact tools, which is characterized.
The method for manufacturing a spindle for an impact tool according to claim 7, wherein a support hole of the support shaft is machined after joining the components.