JPS5952298B2 - Clutch with torque adjustment - Google Patents

Description

[Detailed description of the invention] This invention relates to a clutch with torque adjustment.

The 28th electric tool drive mechanism equipped with a conventional clutch
Shown in the figure.

That is, this mechanism screws and connects the cylindrical adjustment bundle 121 to the case 120, and connects the case 120 and the adjustment bundle 1.
A transmission shaft 124 and a drive shaft 125 are supported in series between ball bearings 122 and 123 installed in the transmission shaft 121, and a clutch plate 126 is mounted on the opposing portion of the transmission shaft 124 and drive shaft 125.
, 127, and steel balls 12 are formed on the surface of the clutch plate 126.
8... are formed on the surface of the clutch plate 127 to form chevron-shaped projections 129 .
Coil spring 1 is placed between coil spring 1 and washer 130 in contact with the inner end surface of
Clutch plate 127 is pressed against clutch plate 126 via 31.

132 is a washer for torque adjustment, 133 is a washer for the transmission shaft,
134 is a click uneven portion, 135 is a click spring, 1
36 is a reduction gear train, and 137 is a motor.

In operation of this mechanism, the transmission shaft 124 is rotated by the rotational operation of the motor 137, and the steel balls 128 are engaged with the chevron-shaped protrusions 129 under the support of the coil spring 131, thereby driving the drive shaft 125. Rotate.

When an overload is applied to the drive shaft 125, the rotational force of the transmission shaft 124 causes the steel balls 128 to push the chevron protrusions 129 in the axial direction by overcoming the spring force of the coil spring 131, thereby reducing the transmission. Only the shaft 124 rotates and the transmission is cut off.

This torque adjustment for set overload is done by adjusting handle 1
By rotating the coil spring 21 (a click operation is performed between the spring 135 and the click uneven portion 134), the amount of compression of the coil spring 131 is changed.

Further, when the adjustment handle 121 is screwed into the case 120 by the maximum amount, the torque adjustment cut-off washer 132 comes into contact with the clutch plate 127 and prevents the clutch plate 127 from moving in the axial direction, resulting in a state in the torque adjustment period.

However, in the above mechanism, the handle 1
210 rotations are required and torque adjustment is troublesome, and parts such as a rotation stopper for the handle 121 and a click spring are required, resulting in a complicated structure and a complicated display for torque adjustment. Ta.

In addition, the chevron-shaped protrusions 129 of the clutch...
Since the steel balls 128 are bent and stand up from the surface of the protrusion 129, the steel balls 128... will be exposed to the chevron-shaped protrusion 129 when engaging or riding over the surface of the steel ball 128.
The chevron protrusion 129 caused a shock by colliding with the slope of...
・There is a problem that the wear resistance and durability of the steel ball are reduced and the operation becomes unstable because the contact between the steel balls becomes discontinuous.

Therefore, an object of the present invention is to provide a clutch with torque adjustment that has a simple structure and torque adjustment operation, is easy to display, and can be made smaller and slimmer.

The present invention includes a first clutch member, a second clutch member facing the first clutch member, and a second clutch member extending radially at equal intervals on a surface of the first clutch member facing the second clutch member. a chevron-shaped protrusion protruding in the direction of the second clutch member; a steel ball protruding from the second clutch member and abutting against a surface of the first clutch member having the chevron-shaped protrusion; a spring means that presses against the first clutch member; a support plate that supports the spring means and forms a support claw; an inclined surface on which the support claw slides and that slopes in the pressure contact direction of the spring means; The clutch handle for torque adjustment is provided with a non-sloped surface that supports a support pawl, and the steel ball, the chevron-shaped protrusion, and the support pawl are arranged on a concentric axis.

Therefore, the torque can be adjusted more easily than before by operating the clutch handle, and since the non-inclined surface also serves as a click, the structure is simplified with fewer parts.

In addition, since the amount of rotation of the clutch handle is small and the torque can be adjusted, it is easier to display the torque.

Furthermore, since the clutch and torque can be adjusted using a single spring means, it can be made smaller, and by arranging the steel balls, chevron-shaped protrusions, and support pawls on the same axis, it can be made thinner.

An electric screwdriver to which an embodiment of the present invention is applied is shown in FIGS. 1 to 27.

That is, this electric screwdriver has a two-split housing 3 made of synthetic resin with a handle 2 provided in the middle part of the body 1.
As shown in FIGS. 3 and 4, a deceleration drive motor section 4 is arranged at the front end of the body section 1, a switch section 5 is arranged at the middle section, a battery section 6 is arranged at the rear end, and a handle section 2. Pit case 7 is placed in the.

The joint part of the two-split housing 3 is a half-part joint,
As shown in FIGS. 8 and 9, hooks 3a and engaging recesses 3b are integrally formed and engaged in several places, and are further connected with screws 3C as shown in FIG. 2.

As shown in FIGS. 4 and 11, the deceleration drive motor section 4 is composed of a two-stage planetary gear deceleration mechanism, and the front surface of the motor 9 is fixed to the motor mounting base 8 with screws 8a.
The motor shaft 10 is made to protrude from the center hole 8b of the motor mount 8, the peripheral edge of the mount 8 is supported by the positioning support rib 11 formed on the inner surface of the body part 1 of the housing 3, and the rear part of the motor 9 is made to be elastically supported. Support rib 13 through body 12
It is housed in the housing 3 while being supported by.

A drive gear 14 is press-fitted onto the motor shaft 10, and a gear case 15 is fixed onto the motor mount 8 with a set screw 15a.

A clutch gear 16 with internal teeth is rotatably inserted into the gear case 15, and a drive shaft 17 is inserted into the clutch gear 16.
A first planetary gear 18 with a transmission gear 19 and a second planetary gear 20 with a transmission gear 19 mesh with each other, the drive shaft 17 is connected to a chuck 21 at the tip, and the transmission gear 19 is connected to the first planetary gear at the center position. The drive gear 14 meshes with the second planetary gear 20 .

In this case, a thrust plate 22a that also supports the clutch gear 16 is interposed between the mounting base 8 and the second planetary gear 20, and the support body 20a of the second planetary gear 20 and the first planetary gear 18 are connected to each other. A thrust plate 22b is interposed between them.

Further, a thrust plate 22C is interposed between the bearing portion 23 of the drive shaft 17 formed at the front end of the gear case 15 and the support body 18a of the first planetary gear 18 to support the gear 18 in the thrust direction. .

The bearing part 23 is composed of a metal bearing 24 made of sintered alloy or the like and a ball bearing 30.
A steel ball 27 is arranged between a pair of thrust plates 25 and 26 in the bearing part 23, and is held between a retaining ring 29 that fits into a circumferential groove 28 formed in the drive shaft 17 and a metal bearing 24. ing.

As shown in FIGS. 12 and 13, chevron-shaped protrusions 31 extending radially at equal intervals and protruding in the axial direction are formed on the peripheral edge 16a of the front end surface of the clutch gear 16, and the protrusions 31... are formed at the center of the upper surface. A groove 31a having an arcuate cross section is formed through which the steel ball passes in the circumferential direction, and a curved surface 32 having a radius of curvature equal to the radius of the steel ball is formed at the rising slope portion of the chevron-shaped protrusion 31.

A stepped portion 33 is formed on the front end side of the gear case 15 in correspondence with the front end surface periphery 16a, and the stepped portion 33 has a ball hole 34.
... are formed, and two steel balls 35 ... are fitted into each of these ball holes 34 ... to remove the inner steel balls 35.
The outer steel ball 35 is pressed against the front end peripheral surface 16a by a thrust plate 36, and the thrust plate 36 is supported by a coiled clutch spring 37.

The clutch spring 37 is fitted and supported on the outer surface of the bearing portion 23 of the gear case 15 with a small gap, and its front end is supported by the clutch plate 38.

Further, the outer surface of the bearing portion 23 has a flat surface 3 in the axial direction on one opposite side surface.
9 is formed, and the clutch plate 38 is attached to this flat surface 39.
It is slidably and non-rotatably fitted to the outer surface containing the material.

Three support claws 40 protrude in the radial direction from the outer peripheral edge of the clutch plate 38, and the support claws 40 form an arcuate surface that bulges forward in the axial direction. It is supported in contact with the inner bottom surface of the bundle 41, and under this support, the steel balls 35 are connected to the front end surface peripheral edge 15a of the clutch gear 16 via the clutch spring 37 and the thrust plate 36.
is in pressure contact with.

The clutch bundle 41 has a cylindrical crown shape and covers the clutch spring 37, and is attached to the body portion 1 as shown in FIGS. 1 and 2.
A knurling 41' and a display protrusion 41'' are formed on the outer surface, and a drive shaft bearing hole 4 is formed in the center of the bottom 41a.
1b, and a pair of circular arc holes 41C arranged symmetrically about the shaft bearing hole 41b are formed in the bottom portion 41a.

A clutch mounting plate 42 is in contact with the outer bottom surface of this clutch bundle 41, and a circular arc hole 41 is fitted with a mounting screw 43.
C, and is screwed to the front end surface of the mounting protrusion 15a formed protrudingly at the front end of the bearing section 23 of the gear case 15, so that the end surface of the bundle 41 comes into contact with the front end opening edge of the body section 1 and is thrust supported. It is radially supported by the drive shaft 17 and rotatably fixed within a regulated range by a mounting screw 43 passing through the circular arc hole 41C.

14 and 15, the clutch bundle 41 further has an arcuate step-like incline of about 120 degrees and a height in the axial direction, corresponding to the three support claws 40, on the inner bottom surface. The surfaces 44 are formed in the same rotational direction, and a continuous concave flat part 44a with a curved surface in the middle is formed. The rotation causes the inclined surface 44 to slide and move to the flat part 441 of different height, thereby changing the amount of compression of the clutch spring 37, and through the clutch gear 16 fixedly supported by the steel ball 35, The torque of the drive shaft 17 is adjusted.

The operation of this deceleration drive motor section 4 is as follows.

That is, the rotation of the motor shaft 10 causes the second planetary gear 2 to rotate.
0 rotates and the clutch gear 16 attempts to rotate.

The clutch gear 16 is pressed in the thrust direction by the steel balls 35 through the thrust plate 36 pressed by the clutch spring 37, which is supported by the thrust plate 22a, and when the clutch gear 16 rotates, the steel balls 35 ... are locked to the chevron-shaped protrusion 31, and unless the steel balls 35... overcome the chevron-shaped projection 31 against the spring force of the clutch spring 37, rotation is restricted and the steel balls 35 are stopped.

This is a state in which no overload is applied to the chuck 21 that holds the bit, and in this case, the support 20a of the second planetary gear 20 rotates and the transmission gear 19 rotates at a reduced speed, thereby causing the first planetary gear 20 to rotate at a reduced speed. When the gear 18 rotates, its support 18a rotates in the same manner as described above, and the drive shaft 17 rotates at a reduced speed to rotationally drive the chuck 21.

On the other hand, when an overload is applied to the chuck 21, the motor shaft 10
The rotational force of is applied to the clutch gear 16, and the chevron protrusion 31 overcomes the spring force of the clutch spring 37 applied to the steel ball 35.
The steel ball 35 is pushed up and rotated.

The spring force of the clutch spring 37 is set by rotating the clutch bundle 41, thereby adjusting the maximum torque of the drive shaft 17.

As shown in FIG. 20, the switch section 5 has a forward/reverse changeover switch 5a, a rotational speed changeover switch 5b, and an on/off switch 5C integrated into one.

As shown in FIGS. 17 to 20, the switch base 45 has disks 45a and 45b at both ends, and supports grooves 46 extending horizontally in the opposite side walls 45C and 45d between them are vertically connected. A protruding portion 46a is formed at the center bottom of the groove 46, and a circular plate 45 is formed at both ends of the supporting groove 46.
It communicates with square holes 47 formed in holes a and 45b.

A guide chipper 47a is formed on the surface side of each square hole 47, as shown in FIG.

Further, an opening 48 that opens into the interior of the switch base 45 is formed in the disc 45a.

Support groove 46 of one side wall 45d of switch base 45...
The plate contact terminals 49a to 49e for the forward/reverse switch are inserted from above the five rectangular holes 47 on the disk 45b side, and the plate contact terminals 49a to 49e are inserted into the disk 45a while being in elastic contact with the surface of the projection 46a.
The protruding portion 46a penetrates through the terminals 47... on the side 47...
Square hole 47 is formed by pressing the middle part of 49e in the thickness direction.
The support groove 46 is elastically supported by being pressed against the inner surface of the support groove 46.
The surfaces of the terminals 49a to 49e located at - are arranged on the surface of the side wall 45d and the road surface.

The rear end portions of the terminals 49a to 49e are folded portions 4 with curved surfaces.
A notch 49 for connecting a lead wire is formed in the center of the folded part 49' and is inserted and positioned at its tip edge.
” is formed.

Further, the terminals 49a to 49e have locking protrusions 49f cut and raised that lock onto the back side of the square holes 47 of the disc 45b in the inserted state.

On the other hand, the support groove 4 of the other side wall 45C of the switch base 45
6..., one piece of the substantially U-shaped contact spring terminals 50a to 50d for the rotation speed changeover switch, which are bent into a substantially U-shape, is inserted from the upper part of the four rectangular holes 47... on the side of the disc 45a. is inserted, climbs over the protrusion 46a in the same manner as described above, and the tip passes through the rectangular hole 47 on the disk 45b side, and the protrusion 46
supported by a.

At this time, the other pieces of the contact spring terminals 50a to 50d have openings 48.
It becomes inserted state.

In addition, the insertion ends of the terminals 50a to 50d are connected to the terminals 49a to 49.
Similar to e, a folded portion 50' and a notch 50'' are formed, and a locking protrusion 50e is cut and raised on the back surface of the rectangular hole 47... side of the disc 45a to prevent it from slipping out, and the support groove 46... The surfaces of the terminals 503 to 50d located at * are exposed to the road surface on the surface of the other side wall 45C of the switch base 45.

Note that the spacing between the support grooves 46 is set so that the mutual spacing X1 between the terminals 50c and 50d is larger than the mutual spacing X2 between the terminals 50b and 50C to an extent that prevents dimensional errors, as shown in FIG. are doing.

A slit 51 is provided in the upper and lower ends of the switch base 45 in the axial direction.
．． A pair of switch covers 54a and 54 having locking claws 53 are formed between the slits 51 and 52.
4b is locked and both side walls 45C, 45 of the switch base 45
It covers d.

One switch cover 54a is for a battery rotation speed change switch, and has three click grooves 55. which extend in the axial direction at the center of the inner surface as shown in FIG. 56. 57, and the center click groove 56 is formed deeper than the other grooves.

The other switch cover 54b is for a forward/reverse switch for the motor 9, and has two click grooves 58 in the center of the inner surface.
．． 59 is formed.

Then, the switch covers 54a, 54b and the switch base 4
Switch plate 60.6 between both side walls 45C and 45d of 5
1 is slidably inserted.

That is, the switch plates 60, 61 each have one side of each of the terminals 49a to 49e, 50a, 50d (7) and a pair of contact fittings 62 with an adjacent spacing. The square push-up spring 63 is locked, and its bent portion 63a is elastically fitted into the click grooves 55 to 59, and the contact fittings 62 are moved to the base 45 by the spring action of the push-up spring 63.
It is in elastic contact with the surfaces of both side walls 45C and 45d.

When the bent portion 63a of the push-up spring 63 on the rotation speed change switch side is engaged with the click groove 56, the contact fittings 62 of the switch plate 60 are connected to the side wall 45C as shown in FIG.
If the terminals 50a to 50d are not in contact with each other, and the click groove 55 is engaged with the terminals 50a to 50d, as shown in FIG.
When the terminals 50b and 50C are contacted with the terminals a to 50C and the terminals 50b and 50C are short-circuited and engaged with the click groove 57, the terminals 50a and 5
0b and terminals 50C and 50d are short-circuited.

Further, when the bent portion 63a of the push-up spring 63 engages with the click groove 58 on the forward/reverse switch side, the terminals 49a, 49
b and the terminals 49C and 49d are short-circuited and the bent portion 63a of the push-up spring 63 engages the click groove 59, the terminal 49b is connected as shown in FIGS. 5 and 18.
, 49C and the terminals 49d and 49e are short-circuited.

The switch bundles 65 and 66 are disks 45a.

It is rotatably fitted and supported in a shaft hole 64 formed by notching 45b, and is located on the upper surface of the covers 54a, 54b.
The lever 67 protruding inward from the bundle 65, 66 extends through the through portion 54a' formed in the switch covers 543, 54b.
, 54b' and engages with the engagement recesses 60a, 61a formed in the switch plates 60, 61, and the bundles 65, 66
By rotating the switch plate 60, 61, the bent portion 63a of the push-up spring 63 moves in the click groove by a click operation.

As shown in FIGS. 19 and 20, the on/off switch contact spring 68 is a plate-shaped body in which folded portions 49' and 50' of terminals 49a to 49e and 50a to 50d on the upper surface of the disc 45b are lined up. located between, and one end of the
It is fixedly supported by a taper support stand 67 provided protruding from the disc 45b by a mounting screw 69 and a positioning protrusion 69', and one end protrudes to one side in the width direction and is inserted into the notch 49'' of the contact terminal 49a located at the end. Inserted and soldered.

The other end of the contact spring 68 is connected to the contact terminal 4 located opposite to the other end.
Both terminals 49e, 50d are located between the contact spring terminal 9e and the contact spring terminal 50d, and the twin contact portions 68a, 68b are extended in both width directions, and the other end of the contact spring 68 is pushed.
The folded portions 49' and 50' of

Both terminals 49e, 50dt near) folded part 49'
, 50' (7) As shown in Fig. 19, there is a dust-proof wall 4.
5b' to maintain good electrical contact with the contact portions 68a and 68b.

The switch section 5 configured in this manner has a circumferential groove 70 formed on the inner surface of the intermediate portion of the body section 1 of the housing 3 by the periphery of the disc 45a of the base 45, as shown in FIGS. 4 and 20.
The bundles 65 and 66 are positioned and supported through the bundle holes 71 and 72 formed in the body part 1, and the discs 45a and 45b are inserted into the trapezoidal protrusion 64a formed in the body part 1.
By engaging and closing the tapered notch 64b of the shaft hole 64, the switch base 45 is positioned in the rotational direction and the bundles 65, 66 are supported axially.

The bundle holes 71 and 72 are located near the base of the handle 2, and are within reach of the thumb and index finger when gripped. An insertion recess 73 is formed, a switch spring 74 is installed on the bottom of the recess 73, an on-off switch bundle 75 is fitted into the recess 73, and a switch spring 74 is formed horizontally at the joint part of the body part 1 as shown in FIG. A flat plate portion 75a formed on the upper part of the bundle 75 is slidably fitted into the guide gap 76, and the bundle 75 is supported in an extended state by the switch spring 74.

A protrusion 77 facing the other end of the contact spring 68 is formed on the flat plate portion 75a of the bundle 75, and a return spring 79 is inserted between the support protrusion 78 cut and raised on the contact spring 68 side and the protrusion plate 77. There is also a flat plate part 7 of the bundle 75.
A tripping protrusion 80 that comes into contact with the contact spring 68 is formed on the side of the contact spring 68 of 5a facing the disk 45b.

In this way, when bundle 75 is pulled (usually with the index finger), switch spring 79 is compressed and the other end of contact spring 68 is pushed via return spring 79.
The contact spring 68 is elastically bent and its contact portions 68a, 68
b contacts the terminals 49C and 50d and is pressed by the return spring 79 to turn on the switch.

On the other hand, when the switch handle 75 is released, the switch spring 74
The bundle 75 is returned by the action of the contact spring 68, and the contact spring 68 is returned by its own spring action and is removed by the tripping protrusion 80.

The electrical wiring of the switch section 5 connects each terminal as follows.

That is, as shown in FIG. 21, each anode side of two battery sets 81 and 82 in which three 1.2V batteries are connected in series is connected to the other piece of the contact spring terminal 50d, 5Qc, and each cathode side is connected to the other piece of the contact spring terminal 50d, 5Qc. are connected to the terminals 50b and 50a (the connection means will be described later).

On the other hand, connect the motor drawing wires 83, 84 to the contact terminals 49b,
Pass through the notch 49'' of 49d and solder.

Further, between the terminals 50a and 49C, a notch 49'' is formed by passing a lead wire 85 between them as shown in FIG.

50" and solder it.

Then, by operating the forward/reverse changeover switch 5a and the rotation speed changeover switch 5b, the contact fittings 62... are set to the instruction symbol P in FIG.

When the contact spring 68 is turned on in the state shown in R, the terminals 50a, 50b are connected by the contact fittings 62...
mutually, terminals 50C550d mutually, terminals 49a, 49
b (7) While short-circuiting the terminals 49C and 49d, the contact spring 68 connects the terminals 49a and 49d to each other.
Since the three parts 49e and 50d are short-circuited, the circuit configuration is such that the battery parts 81 and 82 are connected in parallel to the motor 9, which results in a low-speed normal rotation state.

Next, operate the rotation speed selector switch 5b to exceed the OFF state of the instruction code T (see Fig. 5), and then
In this state (see FIGS. 2 and 18), the circuit configuration is such that the battery units 81 and 82 are connected to the motor 9 in series, resulting in a high-speed normal rotation state.

On the other hand, when the forward/reverse selector switch 5b is operated to set the state indicated by the instruction code S (see Figs. 1, 5, and 18), the circuit configuration is such that the voltage applied to the lead wires 83 and 84 of the motor 9 is The direction is now reversed, and the motor 9 is in a reverse rotation state.

As shown in FIGS. 22 to 25, the battery section 6 forms a cylindrical battery container that fits into the body section 1 by joining a semi-cylindrical battery pack 86 and a battery pack cover 87, and includes three batteries. batteries are connected and held in series with connecting fittings 88 and 89 to form battery parts 81 and 82, which are housed in a pack 86,
It is supported in the axial direction by both end walls 86a, 86b, 87a, and 87b, and partitioned by ribs 90 and an insulating plate 91.

A plug blade holding portion 86C is formed on one end wall 86b of the battery pack 86, and four plug blades 92 are positioned and supported.
Connect and solder the lead wires 93 connected to the battery parts 81 and 82 so as to correspond to the connection with the terminals 501 to 50d shown in FIG. 21 in the direction in which the plug blades 92 are arranged. do.

On the other hand, a plug blade holding portion cover 87C is formed on one end wall 87b of the battery pack cover 87 to cover the plug blade holding portion 86C,
As shown in FIG. 24, only the plug blades 92 are made to protrude to form short-circuit prevention ribs 94 that partition the plug blades 92 from each other.

At the joint between the battery pack 86 and its cover 87, a hook 95 and an engaging recess 96 to be engaged with the hook 95 are formed on one end wall 86b, 87b side, and are fixed with a set screw 97, and the other end wall 86a, 87a is fixed with a set screw 97. A spring insertion hole 98 is formed on the side, into which both end pieces 99a and 99b of a U-shaped retaining spring 99 are fitted, and the end pieces 99a and 99b are elastically supported on the inner surfaces of the pack 86 and the spring bar 87 as shown in FIG. A hook receiving portion 100 is formed on the outer peripheral surface to engage a hook (not shown) of the cap 101, and the pack 86 and cover 87 are combined with each other by these structures.

Further, as shown in FIGS. 1 and 2, the rear end of the body part 1 is open and cutouts 1a and lb are formed on both sides of the rear end, and corresponding to the cutouts 1a and 1b, , Pack 86
A U-shaped cutting line 102 is formed on the outer surface of the cover 87 to form a presser button 103 that bends due to the elasticity of the resin material itself. The pack 86 and the cover 8
The insertion amount of 7 is determined.

As shown in FIG. 24, both end pieces 99a and 99b of the holding spring 99 come into elastic contact with the back surface of the presser button 103 to support the presser button 103 in its returned state.

On the other hand, when the pack 86 and cover 87 are inserted,
As shown in FIG. 6, the plug blade holding portion 86C is
The plug blades 92... contact the other pieces of the corresponding contact spring terminals 50a to 50d to connect the terminals 50a to 50d and the battery part 81.82 in FIG. ing.

The handle part 2 is as shown in FIGS. 4, 26, and 27.
The rear end is open to form a pair of notches 107 and a hook fitting recess 108 .

On the other hand, elastic handle parts 109 that fit into the notches 107 are integrally formed on both sides of the bit case 7, and a hook 110 is formed at the tip of the handle part 109 so that the hook 110 can be inserted into the recess 10.
8 to fit.

The bit case 7 has a recess 112 that can store the handle 111a of the chuck bundle 111 vertically on the side that fits into the handle 2, and a bit (+) 113 and a bit (-) on both sides of the handle storage recess 112a. )114
storage recesses 113a and 114a are formed, respectively, so that the tip protrusions of the bits 113 and 114 and the chuck bundle 111 are stored in the handle portion 2.

Next, the functions and effects of this power tool will be explained.

That is, (1) As shown in FIGS. 3 and 4, the overall structure is pistol-shaped with the handle part 2 located at the middle part of the body part 1, and the front end of the body part 1 has a deceleration drive motor part 4 and a middle part. Since the switch part 5 is arranged at the rear end, the battery part 6 is arranged at the rear end, and the bit case 7 is stored in the handle part 2, the weight balance of the body part 1 with respect to the handle part 2 is appropriate.
Even when the bits 113 and 114 and the chuck bundle 111 are removed, the weight balance does not change, making it easy to use even when working on vertical walls, and preventing wrist fatigue.

(2) In the clutch, the chevron-shaped projection 31 formed on the front end periphery 16a of the clutch gear 16 as shown in FIG. 11 is curved between the rising slope of the projection and the periphery 16a as shown in FIG. In the case of
There is less impact when the protrusion 5 crosses over, the abrasion resistance of the protrusion 31 is improved, the durability is improved, and the operation becomes stable and smooth, reducing variations.

Further, since the groove 31a having an arcuate cross section is formed on the upper surface of the chevron-shaped protrusion 31, the steel balls 35 do not crush the chevron-shaped protrusion 31, resulting in a long clutch life and stable clutch operation.

(3) In the torque adjustment device, the other end of the clutch spring 37 that presses the steel ball 35 is prevented from rotating because it engages with the chevron-shaped protrusion 31 of the clutch gear 16 to restrict rotation as shown in Fig. 11. Since the clutch plate 38 is supported on the flat part 44a of the inclined surface 44 on the inner bottom surface of the clutch handle 41 as shown in FIG. A wide range of spring compression can be achieved with a small amount of operation, and the angle of inclination of the inclined surface 44, the number of flat portions 44a, and the amount of spring compression can be arbitrarily set regardless of the rotation angle of the handle.

In addition, the stable locking by the flat portion 44a makes it possible to achieve clickability without the need for extra parts such as a rotation stopper or a click spring for the handle 41, which were required in the past, simplifying the structure and making it easier to adjust the torque. Display can be easily and clearly displayed.

By forming the support pawl 40 of the clutch plate 38 into an arcuate surface, sliding on the flat portion 44a and the inclined surface 44 is made smooth, the operation of the handle 41 is facilitated, and the clicky switch feeling is improved.

Furthermore, if the maximum height of the flat portion 44a is set so that the clutch spring 37 is in a state where the coil is in close contact with the coil, the steel ball 35 will not be able to get over the protrusion 31, so the state of the torque adjustment device can be achieved. It is possible to reduce the number of components that make up the system and simplify the mechanism.

Note that when the inclined surface 44 is used for torque adjustment, the same effect as described above can be obtained even if the clutch handle 41 is fixed and the clutch plate 38 is configured to rotate.

(4) Regarding the bearing of the drive shaft 17, see Figures 4 and 11.
As shown in the figure, metal bearing 24, steel ball 27, thrust plate 25
, 26 and a retaining ring 29.
The thrust load is handled by ball bearing 3.
0, the thrust bearing effect can be exhibited, and the radial load is received by the metal bearing 24 and steel ball 27, so there is less rattling than a cantilever structure with only metal bearings or one ball bearing, and it has good accuracy and durability. Become something.

Also, the bearing part 23 of the gear case 15 is used to support the outer periphery of the steel ball 27.
By using the inner surface of the ball bearing, the structure becomes simpler and cheaper than a double-supported structure using two ball bearings.

At this point, as shown in FIG.
A may be formed to support the outer periphery of the steel ball 27 in the recess 24a.

By positioning the clutch spring 37 outside the bearing portion 23, the axial length can be shortened compared to the conventional case where the bearing and clutch spring are arranged side by side in the axial direction, and the torque adjustment device can be made smaller. can be achieved.

(5) In the switch unit 5, as shown in FIG.
Since the switch is integrated so that it is located on three sides, the housing that houses the switch is more compact than the conventional separate and independent case, and lead wire connections can be omitted, making assembly easier and reducing the number of parts. and can reduce costs.

Forward/reverse changeover switch 5a and rotation speed changeover switch f-5b
By providing the switch handles 65 and 66 near the handle part 2 of the body part 1 within the reach of the thumb and forefinger while holding the handle, the switch 3@ can be operated with one hand, making it extremely convenient to use. , Frequently used □ If the handle 66 of the forward/reverse changeover switch 5a is placed on the left side facing forward as shown in FIG. 1, it will be easier to use since the right-hand handle can be operated with the thumb.

By setting the rotation speed selector switch 5b in an off (power off) state, it is possible to inadvertently pull the on/off switch 5C (this is highly likely as the bundle 75 is located in the direction of the handle of the handle section 2) and the motor 9 will be activated. This eliminates the need for a locking device.

The switch-off configuration is such that a click groove 5b is formed in the switch cover 54a, and when the push-up spring 63 is engaged with the click groove 56, the contact fitting 62 is connected to the contact spring terminals 50a to 50.
This is achieved by keeping the distance between 0d and not in contact with these.

In this case, if the depth of the click groove 56 is made deeper than the other click grooves 55 and 57 adjacent to it, the switch bundle 65 is operated to cause the push-up spring 63 to
Although it is easy to move from the click groove 57 to the click groove 56, it is difficult to move from the click groove 56 to the click groove 55.
This prevents the material from accidentally jumping over the click groove 56 from the click groove 55 to the click groove 57 or vice versa.
This prevents incorrect rotation speed switching and off operations, improving safety, preventing damage to equipment, and extending its life.

On the other hand, as shown in FIG.
By setting Xo>X2 with respect to the mutual spacing X2 of 0b, the overall spacing between the respective terminals can be set to the minimum possible spacing, while contact failure due to dimensional variations with respect to the contact fittings 62 can be prevented. The switch structure can be made smaller and reliability can be improved.

Note that a switch-off configuration may be added to the forward/reverse changeover switch 5a.

As shown in FIG. 5 and FIG.
Since the trapezoidal protrusion 64a that engages with the switch 4b is provided, the switch base 45 can be reliably positioned without wobbling, and it also prevents the switch bundles 65 and 66 from being disassembled unexpectedly, making them resistant to external forces such as dropping impact and improving reliability. At the same time, assembly becomes easier.

5) As shown in Figs. 19 to 21, the contact spring 68 of the on/off switch 5C also serves as a short circuit between the contact terminals 49a and 496 at both ends of the forward/reverse changeover switch 5a, which makes the connection shorter than when short-circuiting with a lead wire. This results in a reduction in the number of parts, assembly man-hours, and costs.

Since the contact portions 68a and 68b of the contact spring 68 are twin-shaped, contact reliability is improved.

Further, since the contact spring 68 is pushed through the return spring 79, a constant and stable contact pressure can be obtained, and at the same time, it is possible to prevent the contact spring from weakening.

Furthermore, the return of the contact spring 68 is not only due to its own spring action due to being supported by the tapered support base 67, but also due to the tripping protrusion 80 of the switch bundle 75.
Since the contacts are forcibly pulled back by the action of step 4, even if the contacts become welded when a large current flows, they can be pulled apart reliably.

(7) Contact terminals 49a to 49e and contact spring terminal 50
a to 50d have a folded part 49 at one end as shown in FIG.
', 50' are formed, and notches 49'', 50'' for lead wire soldering are formed in the folded parts 49', 50', so the surfaces of the folded parts 49', 50' can be used as contact points, and the notches 49'' Since the lead wires can be soldered to the .

Moreover, since there are two contact points due to the notches 49'' and 50'', the contact is stable and reliability is improved.

As shown in FIGS. 6 and 20, the terminal mounting portion of the switch base is configured such that terminals 49a to 49e and 50a to 50d are elastically deformed into a slightly dogleg shape by holes 47 at both ends, support grooves 46, and protrusions 46a. In addition, the terminals 49a to 49e and 50a to 50d are provided with retaining protrusions 49.
Since C950e was cut and cut, terminals 491 to 49e,
5Qa to 50d can be securely installed by press-fitting from one side, and assembly is easier and more accurate than conventional switch bases that have a structure in which the terminals are held in place by dividing them, or structures that require caulking after insertion. positioning, and costs can be reduced by reducing the number of parts.

In this case, the guide taper 47a formed in the hole 47...
... facilitates the insertion of the terminal.

(8) The battery section 6 is made into a block with a battery pack 86 and a pack cover 87 as shown in FIG. 4 and FIG.
Because it is connected to the switch unit in a removable manner, repairing the battery unit 6 is easy.If you prepare two types of battery blocks and make one or both of them rechargeable, it is easy to replace the power supply unit. This makes it convenient to use power tools continuously.

Furthermore, in the case of charging, the housing structure can be made simple and compact by housing the charging module within the battery pack 86 and cover 87.

As shown in FIG. 24, the protruding portion of the plug blades 92 is provided with a short-circuit prevention rib 94 on the pack cover 87 that separates the plug blades from each other, so that the conductor Y may unexpectedly come into contact with the plug blades 92 as shown in the same figure. prevents them from touching each other and shorting each other, and does not adversely affect battery life.

Further, the rib 94 functions to guide the plug blade 92 by entering the gap between the contact spring terminals 50a-1-50d projecting into the opening 48 of the switch base 45.

As shown in FIG. 22, the battery pack 86 and the pack cover 87 are connected by a hook 95, a screw 97, a retaining spring 99, and a cap 101, so that they do not disintegrate due to impact and are bonded together. This is more advantageous than the case where it is joined by screws, and it is easier to assemble and has a better appearance than the case where it is joined by tightening three or four screws.

The holding spring 99 has both end pieces 99a and 99b elastically installed on the back surface of the hook 104 that engages with the housing 3 as shown in FIG. This ensures the engagement of the battery part 6 and prevents the battery part 6 from coming off due to impact.

(9) As shown in FIGS. 26 and 27, the handle part 2 has a bit case 7 detachably attached thereto, and the bits 113, 114 and chuck bundle 111 are stored in the bit case 7; It is easier to put in and take out the bits 113 and 114 than when they are stored, and by forming the storing direction in the mounting direction of the bit case 7, the bit case 7 can be made narrower, making the entire power tool more compact. .

In addition, by providing the bit case 7 in the handle part 2, the overall length of the body part 1 can be shortened, and the dust generated during operation is covered with the hand holding the handle part 2, making it difficult for the case 7 to come into contact with the bit 113°. 114 and prevents rust from occurring.

By forming the bit (+) 113 and the bit (-) 114 on both sides of the handle portion 111a of the chuck bundle 111 in the housing portion of the bit case 7, the space can be used more effectively and more compactness can be achieved.

Since the bit case 7 is removably attached to the handle portion 2 using an integrally formed hook 110, the number of parts can be reduced, ease of assembly can be improved, and the user will not lose attachment parts.

As described above, according to the clutch with torque adjustment of the present invention, the structure and torque adjustment operation are simple, the clutch can be made small and slim, and the display can be easily displayed.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of an electric driver to which an embodiment of the present invention is applied, as seen from one side, Fig. 2 is a perspective view of the electric driver as seen from the other side, Fig. 3 is a block diagram of its internal structure, and Fig. 4. 5 is a detailed sectional view thereof, FIG. 5 is a sectional view taken along the line v-V, FIG. 6 is a sectional view taken along the vI-vI line, and FIG. 7 is a sectional view taken along the line VII-V of FIG.
8 is a sectional view taken along the line VTN-VNT of FIG. 4, FIG. 9 is a sectional view taken along the line X-X of FIG.
Figure 11 is an exploded perspective view of the deceleration drive motor, Figure 12 is a front view of the clutch gear, Figure 13 is a cross-sectional view of the clutch gear, and Figure 4 is a rear view of the clutch bundle. Figure 15 is a sectional view taken along the line
III line sectional view, Figure 19 is the front view of Figure 17,
Figure 0 is an exploded perspective view of the switch part, Figure 21 is an electrical wiring diagram of the motor including the switch part, Figure 22 is an exploded perspective view of the battery part, Figure 23 is a side view of the battery part, and Figure 24 is an exploded perspective view of the battery part. SonoX
A sectional view taken along the line XIV-XXIV, Fig. 25 is a partial view thereof, Fig. 26 is a partially exploded perspective view of this embodiment, Fig. 27 is a sectional view of the bit case, and Fig. 28 is a power tool equipped with a conventional clutch. FIG. 15... Gear case, 16... Clutch gear (clutch member), 16a... Front end surface periphery, 17... Drive shaft, 18... ...First planetary gear, 31...Chevron protrusion, 31a...
...Arc-shaped groove in cross section, 33...Step part (clutch member), 34...Hole, 35...Steel ball, 3
7...Clutch spring, 38...Clutch plate (support plate), 40...Support claw, 41...
...Clutch bundle (torque adjustment bundle), 4
4... Slanted surface, 44a... Flat portion (non-sloped surface).

Claims (1)

[Scope of Claims] 1. A first clutch member, a second clutch member facing the first clutch member, and a surface of the first clutch member facing the second clutch member, etc. a chevron-shaped protrusion that extends radially at intervals and projects in the direction of the second clutch member; a steel ball that protrudes from the second clutch member and abuts against a surface of the first clutch member having the chevron-shaped protrusion; a spring means for press-contacting the steel ball to the first clutch member; a support plate supporting the spring means and forming a support pawl; and the support pawl sliding and tilting in the press-contact direction of the spring means. A clutch with torque adjustment, comprising: a clutch bundle for torque adjustment in which an inclined surface and a non-inclined surface supporting the support pawl are continuously formed, and the steel ball, the chevron-shaped protrusion, and the support pawl are arranged on a concentric axis. 2. The chevron-shaped protrusion has a groove with an arcuate cross section through which the steel ball passes in the circumferential direction, and a curved surface that is continuously formed on a rising slope of the chevron-shaped protrusion and has a radius of curvature comparable to the radius of the steel ball. A clutch with torque adjustment according to claim 1. 3. The torque adjustment according to claim 1, wherein the clutch bundle has a cylindrical shape, and an inner surface of the clutch bundle has a stepped portion formed by the inclined surface and the flat non-inclined surface. With clutch.