CN204019433U - Screwdriver - Google Patents

Abstract

The utility model relates to a kind of screwdriver, comprise casing, be arranged in casing and the motor of outputting rotary power, and the output shaft being connected with described motor, described output shaft can move axially and have in the axial direction along central axis the operating position of a plurality of output rotations, described screwdriver also comprises position-limit mechanism, described position-limit mechanism is for being limited in described output shaft operating position described in one of them, described screwdriver also comprises the magnetic keeper being connected with the front end of described output shaft, described magnetic keeper is for helping the screw being driven by work screwdriver bit.

Description

Screwdriver

Technical field

The present invention relates to a kind of screwdriver, relate in particular to and a kind ofly can under various working, use and have the screwdriver of magnetic keeper.

Background technology

In existing drill gun class power tool, generally include electric drill, electric screwdriver and percussion drill.

Electric screwdriver be for by screw-driving to a kind of conventional electric tool on workpiece.When need to operate under different operating modes in use procedure, for example screw-driving is arrived to the narrow and small position of workpiece, because working head length is too short in and stubborn screw, need to change long working head, namely screwdriver bit, will take off the working head of original installation, then load onto long working head, or additionally buy an annex adapter, in needs, working head is arranged on adapter, then adapter is installed to electric screw pulls on.At needs, frequently change under the use occasion of working head, to operator, brought great inconvenience, caused on the one hand replacing working head or replacing annex loaded down with trivial details, the working head taking off on the other hand or adapter are placed easy loss everywhere.In some hand-operated tools, have some storage that can realize working head and quick-replaceables, still, due to the inherent defect of hand-operated tools, moment of torsion is little, operation is hard, make operator be easy to fatigue, cause inefficiency, be not suitable for as professional instrument, using in industrial sector.

In addition,, while using screwdriver screwdriver bit to turn screw, conventionally first need to stablize screw, to prevent that screwdriver screwdriver bit from skidding or preventing screw displacement.During use, operator can use one or two finger to stablize screw conventionally, then with screwdriver screwdriver bit, turns screw.But along with the rotation of screw, screw likely can skid at surface of the work, and from operator is hurt.In addition, screw is being back-outed and made from workpiece, screw often drops from screwdriver screwdriver bit, thereby makes operation inconvenience.For addressing the above problem, conventional way is in the industry, makes screwdriver screwdriver bit have magnetic.So, when using screwdriver screwdriver bit to turn screw, can make screw be adsorbed on screwdriver screwdriver bit, can make like this screw by the stable workpiece that is screwed into.And when screw is screwed out workpiece, it can be adsorbed on screwdriver screwdriver bit, can not drop.

Summary of the invention

For the deficiencies in the prior art, the object of the present invention is to provide and a kind ofly can under various working, use and screw is had the screwdriver of stable support function.

The technical solution adopted for the present invention to solve the technical problems is: a kind of screwdriver, comprising: casing; Motor, is arranged in casing, and outputting rotary power; Output shaft, is driven by motor, has central axis, the front end of output shaft have axial setting for connecting the accepting hole of work screwdriver bit, the target of described work screwdriver bit is screw; Described output shaft can move axially and have in the axial direction along central axis the operating position of a plurality of output rotations, described screwdriver also comprises position-limit mechanism, described position-limit mechanism is for being limited in described output shaft operating position described in one of them, described screwdriver also comprises the magnetic keeper being connected with the front end of described output shaft, and described magnetic keeper is for helping the screw being driven by work screwdriver bit.

Described screwdriver can also comprise transmission mechanism, and described transmission mechanism is arranged between described motor and described output shaft and the rotary power of described motor output can be passed to described output shaft.

Preferably, described screwdriver also comprises connector, and described magnetic keeper is connected with the front end of described output shaft by described connector.

Preferably, described connector is the ring set structure with through hole, and described work screwdriver bit runs through described through hole; Described connector comprises first end and the second end, and described first end connects described magnetic keeper, and described the second end connects the front end of described output shaft.

Preferably, described magnetic keeper is connected with the end face of described first end.

Preferably, the end face of described first end is provided with accepting groove, and described magnetic keeper is contained in described accepting groove.

Preferably, described the second end is removably connected with the front end of output shaft.

Preferably, described the second end is provided with internal thread, and the front end of described output shaft is provided with external screw thread, and described connector is connected by described internal and external screw thread with the front end of described output shaft.

Preferably, described connector is connected by buckle structure with the front end of described output shaft.

Preferably, described connector is connected by adhesive with described output shaft.

Preferably, described magnetic keeper is the ring set structure with through hole, and described work screwdriver bit runs through described through hole; Described magnetic keeper comprises the link being connected with the front end of described output shaft.

Preferably, described link is removably connected with the front end of described output shaft.

Preferably, described link is provided with internal thread, and the front end of described output shaft is provided with external screw thread, and described link is connected by described internal and external screw thread with the front end of described output shaft.

Preferably, described link is connected by buckle structure with the front end of described output shaft.

Preferably, described magnetic keeper is annular.

Preferably, described magnetic keeper is arranged on the front end end face of described output shaft.

Compared with prior art, the invention has the beneficial effects as follows: screwdriver of the present invention is used at narrow space by the flexible realization of output shaft, can beat deep hole, edge and other are difficult for touching local screw, also there is the function of helping screw simultaneously; And screwdriver of the present invention is easy to operate, without being equipped with extra annex, cost is lower.

Accompanying drawing explanation

Fig. 1 is the front view of the screwdriver of the preferred embodiment of the invention one;

Fig. 2 be embodiment mono-screwdriver output shaft be positioned at the cutaway view of the first operating position;

Fig. 3 is that the screwdriver of embodiment mono-is along the cross-sectional schematic of A-A line;

Fig. 4 be embodiment bis-screwdriver output shaft be positioned at the cutaway view of the first operating position.

Wherein,

1. casing 2. motor 3. transmission mechanisms

4. output shaft 5. operating mechanism 6. batteries

7. press button 9. work screwdriver bit 11. handles

Spacing gusset 15. flutings of 13. fore shell 14.

16. chute 21. motor shaft 22. gear-boxes

224. stopper section 31. planetary gear reducing mechanism 32. pinion gear mechanisms

301. first gear 302. second gear 303. the 3rd gears

308. gear shaft 40. sleeve 41. accepting holes

42. back-up block 422. leg 43. support ends

44 magnetic keeper 45. connector 51. slide blocks

52. separate lock dog 521. accommodation section 522. draw-in grooves

523. first separate lock section 524. second separates lock section 81. locating parts

83. spring 84. abutting part 85. first lock pawls

86. second lock pawls

The specific embodiment

In the preferred embodiment of the present invention, screwdriver is power screwdriver, according to the difference of power source, can be divided into pneumatic screw criticize, surge screwdriver and electric screwdriver, in electric screwdriver, also have direct current and exchange minute, the present invention preferably be take DC electric screw batch and is specifically described as example.

Embodiment mono-

Shown in seeing figures.1.and.2, this DC electric screw batch comprises casing 1, motor 2, transmission mechanism 3, output shaft 4 and battery 6.Transmission mechanism 3 is arranged between motor 2 and output shaft 4 and the rotary power of described motor 3 outputs can be passed to output shaft 4.Casing 1 is closed up and is assembled by screw (not shown) by symmetrical two and half housings, its have horizontal component and with horizontal component handle 11 parts that K arranges in obtuse angle, the preferred angle K of the present invention is at 100 degree between 130 degree, and when gripping handle 11 operates like this, meeting is pleasant.Top in handle 11 parts is provided with press button 7, and battery 6 is fixed on the rear portion of handle 11 parts, and transmission mechanism 3 is housed in the horizontal component of casing 1.As preferred embodiment, battery 6 is lithium ion batteries.It should be noted that, said lithium ion battery is the general name of lithium ion reversible rechargeable battery of deviating from and embedding between positive pole and negative pole here, according to the difference of positive electrode, it can form many systems, as " lithium cobalt " battery, " lithium manganese " battery, " lithium iron " battery etc.In the present embodiment, lithium ion battery is that a joint rated voltage is the lithium ion battery of 3.6V (volt).Certainly, battery 6 can be also the battery types well known to those skilled in the art such as NI-G, ni-mh.

Transmission mechanism 3 comprises by the right side of drawing (take as rear) before backward the planetary gear reducing mechanism 31 and the pinion gear mechanism 32 that by motor 2, are driven, and wherein pinion gear mechanism 32 is connected with output shaft 4 and drives output shaft 4 rotations.

Motor 2 in the preferred embodiment for the present invention is motor, and motor has from electric machine casing extended motor shaft 21 forward.Motor is fixed in casing 1, and a gear-box 22 is fixed in casing 1 and is positioned at the front portion of motor, and gear-box 22 is for accommodating planetary gear reducing mechanism 31.Pinion gear mechanism 32 comprises the first gear 301 can transmitting torque being connected by a gear shaft 308 with planetary gear reducing mechanism 31, the 3rd gear 303 being connected with output shaft 4 and the second gear 302 simultaneously meshing with the first gear 301 and the 3rd gear 303, so setting can make the rotation of output shaft 4 parallel with respect to the rotation of motor 2.Certainly, also the rotation of output shaft 4 can be to angle setting with respect to the rotation of motor 2 if needed.Wherein gear shaft 308 can be wholely set with the first gear 301, and the second gear 302 passes to the 3rd gear 303 by the rotation of the first gear 301, and the two ends of each gear are supported by axle sleeve.The rear axle housing that supports pinion gear mechanism 32 is fixed on gear-box 22, and front shaft sleeve is fixed on fore shell 13.

Certainly, also can be arranged to as required two gears, one is connected with planetary gear reducing mechanism 31, and another is connected with output shaft 4.In addition, transmission mechanism 3 is not limited to above-described form, and transmission mechanism 3 can only include planetary gear reducing mechanism 31, or only includes pinion gear mechanism 32, or other the transmission mechanism that rotatablely moves, as ratchet mechanism, turbine mechanism etc.Wherein planetary gear reducing mechanism 31 has three grades of deceleration systems, and motor shaft 21 extends and planetary gear reducing mechanism 31 engagements, and planetary gear reducing mechanism 31 will rotatablely move and pass to pinion gear mechanism 32, and pinion gear mechanism 32 drives output shaft 4 rotations.When motor 2 moves like this, by planetary gear reducing mechanism 31, pinion gear mechanism 32, finally by output shaft 4, exported.In addition, reducing gear is slowed down by third-level planetary and two-stage parallel axis deceleration system forms to obtain wanted output speed, in other embodiments, and depending on the rotating speed of required output, reducing gear can only include secondary planet deceleration system, or other deceleration systems.

The front end of output shaft 4 has the accepting hole 41 of axial setting, accepting hole 41 is interior for installment work screwdriver bit 9, the cross section of conventional standard operation screwdriver bit 9 shanks is orthohexagonal, it is the moment of torsion forced section that shank forms work screwdriver bit 9, the form that accepting hole 41 is arranged to the hexagonal hole that the moment of torsion forced section with the screwdriver bit 9 of working matches, can realize output shaft 4 to the moment of torsion transmission of work screwdriver bit 9.Certainly, what work screwdriver bit 9 also can the criteria of right and wrong, the cross section of moment of torsion forced section is polygonal shape, corresponding accepting hole 41 is arranged to the polygon matching with moment of torsion forced section, can realize the transmission of moment of torsion.In addition, in accepting hole 41, can be fixedly installed magnet, for keeping work screwdriver bit, the screwdriver bit that prevents from working when output shaft 4 down drops.The front end of output shaft 4 is supported on fore shell 13 by an axle sleeve 40, and axle sleeve 40 provides radial support to output shaft 4, can certainly realize by bearing the radial support of output shaft 4.Output shaft 4 is structure moment of torsion acceptance division at least partly, moment of torsion acceptance division is set to six square shafts, the cross section that is moment of torsion receiving portion is hexagon, in the 3rd corresponding gear 323, be provided with hexagonal hole, the 3rd gear 323 is the roller gear of external toothing, it passes to output shaft 4 by hexagonal hole by moment of torsion, therefore hexagonal hole is configured to the torque transfer part of the 3rd gear 323, output shaft can move and the moment of torsion receiving portion of output shaft and the torque transfer part of the 3rd gear 323 maintenance engagement in hexagonal hole, so no matter how output shaft moves axially and can realize moment of torsion transmission, the 3rd gear 323 passes to output shaft 4 by rotary power, and then output shaft 4 drives 9 rotations of work screwdriver bit.

The front end of output shaft 4 is also connected with magnetic keeper 44, the target screw (not shown) driving for support work screwdriver bit 9.Magnetic keeper 44 is connected with output shaft 4 indirectly by connector 45.Connector 45 is ring set structure, and magnetic keeper 44 is annular magnet keeper.Certainly, connector 45 can be also that other can realize the structure of helping function.The first end end face of connector 45 is provided with annular accepting groove, for accommodating magnetic keeper 44.The second end of connector 45 is connected with the front end of output shaft 4.Preferably, the second end is detachably connected with the front end of output shaft 4.The second end inner side is provided with internal thread, and the front end outer surface of output shaft 4 is provided with external screw thread.Connector 45 is connected by screw thread with the front end of output shaft 4.Certainly, the second end with being connected of front end of output shaft 4 also have other modes, as buckle connects.Connector is after accepting hole 41 connection work screwdriver bits 9, and magnetic keeper 44 is looped around around work screwdriver bit 9, produces the effect of helping screw.The kind of magnetic keeper 44 comprises magnet, magnet steel and the magnetic material of other tools.Can be flexible in the axial direction at magnetic keeper 44 by being threaded of connector 45, adjust the working space of work screwdriver bit 9, produce the effect of helping screw simultaneously.

The rear end axial restraint of output shaft 4 be provided with a back-up block 42, the shape that back-up block 42 is cubic hollow, output shaft 4 has the support end 43 that connects back-up block 42, support end 43 is arranged to cylindrical, one side of back-up block 42 is provided with circular hole or U-shaped hole, support end 43 passes circular hole, U-shaped hole is rotating is supported on back-up block 42, thereby annular groove can be set on support end 43 and can assemble back-up ring, or the shaft shoulder is set and is stuck on back-up block 42, to carry out spacing to moving axially of output shaft 4.The diameter of support end 43 is preferably less than output shaft 4 six sides' external diameter of a circle, thereby the volume that can reduce like this back-up block 42 makes the structure of instrument integral body compacter.On back-up block 42, another side relative with circular hole or U-shaped hole and the end of support end 43 offset, wherein the end of support end 43 is arranged to coniform or spherical, output shaft 4 is some contact with contacting of back-up block 42 like this, because electric screwdriver need to axially be pressed on workpiece by work screwdriver bit 9 when operating, work screwdriver bit 9 can be subject to a reverse responsive to axial force like this, this axial force can pass to output shaft 4, between output shaft 4 and back-up block 42, will produce larger stressed friction, the mode of some contact can reduce friction, increase the service life of output shaft 4.In addition, can make output shaft 4 and back-up block 42 all adopt metal to make, reduce the degree of wear between output shaft 4 and back-up block 42.And back-up block 42 can connect by the shape of a plurality of cubic hollows, to gain in strength.The advantage that back-up block 42 can also have other is set, such as output shaft 4 is rotatable, is supported on back-up block 42, without using bearings, reduce volume and the cost of instrument.

For electric screwdriver can also can be operated at narrow space, output shaft 4 is arranged to move vertically, be that output shaft 4 at least has the first operating position that axial upper relative proximity casing 1 output rotates and axially above relatively away from casing 1, also exports second operating position of rotating, because the torque transfer part of the moment of torsion receiving portion of output shaft and the 3rd gear 323 keeps engagement, no matter output shaft 4 is in the first operating position or the second operating position, and the 3rd gear 323 can both drive output shaft 4 rotations.Because of approximately one inch of the length of conventional work screwdriver bit, preferably the distance of output shaft 4 removable elongations is greater than the length of a work screwdriver bit, that is to say that the distance of output shaft 4 removable elongations is greater than 25 millimeters.Although be that the longer the better for the distance of output shaft 4 removable elongations, in order to make small and exquisite being easy to carry of overall dimensions of electric screwdriver, the distance of output shaft 4 removable elongations is approximately less than the length of one 4 inches work screwdriver bits, i.e. the distance of output shaft 4 removable elongations is less than 110 millimeters.Certainly, output shaft 4 is not limited to two above-mentioned operating positions, three or more can be set in actual use procedure as required and output shaft 4 can be moved axially to the operating position of locking.

Electric screwdriver need to axially be pressed on work screwdriver bit 9 on screw or workpiece when operating, work like this 9 and can be subject to a reverse responsive to axial force, thereby produce output shaft 4 after move.Electric screw is pulled on and is provided with position-limit mechanism, position-limit mechanism comprises the spacing gusset 14 being fixedly installed on casing 1, thereby when output shaft is positioned at the first operating position, the rear end of back-up block 42 and spacing gusset 14 are axially against output shaft (towards the direction of motor 2) motion backward.Accordingly, in order to limit output shaft, be positioned at (away from the direction of the motor 2) motion forward of the second operating position, position-limit mechanism also comprises the stopper section 224 being fixedly installed on gear-box 22, thereby when output shaft is positioned at the second operating position, the front end of back-up block 42 and stopper section 224 axially cannot travel forward against output shaft.

Shown in Fig. 3, position-limit mechanism can limit or allow output shaft movement towards motor 2 directions on the second operating position, and position-limit mechanism further comprises the spring 83 that is arranged on pivotable locating part 81 between output shaft 4 and casing 1 and bias voltage locating part 81.Locating part 81 has restriction output shaft 4 locked position moving and the off-position that allows output shaft 4 to move, and spring 83 compresses locating part 81 to locked position.On locating part 81, along output shaft axially spaced-apart, be provided with the first lock pawl 85 and second and lock the end that pawl 86, the first lock pawls 85 are positioned at one end of locating part 81, the second lock pawl 86 is the middle part for locating part 81 along the radial convex that can contact with output shaft 4.When output shaft 4 is positioned at the first operating position, the axial butt of front end of the first lock pawl 85 and back-up block 42, output shaft 4 is limited forward (away from the direction of motor 2) motion; When output shaft 4 is positioned at the second operating position, the axial clamping in rear end of the second lock pawl 86 and back-up block 42, output shaft 4 is limited to move backward.So by a locating part just can realize output shaft in the second operating position spacing and output shaft backward in the first operating position forward spacing, saving parts are saved space simultaneously.The sidepiece area of back-up block 42 is large, facilitates locating part 81 and back-up block 42 to offset with to output shaft 4 axial limitings.The other end of locating part 81 is arranged on casing 1 by a bearing pin, and the axis of bearing pin is perpendicular to the axis of output shaft 4, and locating part 81 can rotate around bearing pin within the scope of certain angle.Spring 83 can be torsion spring or stage clip, in the present embodiment, be preferably stage clip, one end of stage clip is pressed on locating part 81, and the other end is against on gear-box 22 or on casing 1, and the elastic force of stage clip makes locating part 81 remain on the locked position (shown in Fig. 3) with back-up block 42 butts.Such locating part 81 preferably arranges two, symmetrical along the axis of output shaft 4, can keep stress balance like this, makes the axial limiting of output shaft 4 more reliable.

On casing 1, be connected with operating mechanism 5, operating mechanism 5 comprises and is arranged at the slide block 51 of casing 1 outside and is arranged at the solution lock dog 52 being fixedly connected with slide block 51 in casing, the both sides of casing 1 are provided with the chute 16 extending vertically, and the connectors such as bearing pin or screw are conciliate slide block 51 with lock dog 52 through chute 16 and linked together.So arrange, can prevent that dust, foreign material etc. from falling in casing 1, for further enhanced leaktightness effect, can on chute 16, connect and not affect the flexible sealing strip that bearing pin moves.Certainly, slide block 51 is conciliate lock dog 52 and also can be wholely set, and can between slide block 51 and casing 1, folding sealing device be set and prevent dust.Solution lock dog 52 has the accommodation section 521 of hollow, and back-up block 42 is positioned at accommodation section 521 at least partly, so makes the internal structure of electric screwdriver compact, and instrument integral body is smaller and more exquisite.On accommodation section 521 sidewalls of solution lock dog 52, be arranged with vertically draw-in groove 522, corresponding back-up block 42 is arranged with leg 422 vertically, leg 422 is connected in draw-in groove 522 and can in draw-in groove 522, at certain distance, slides, therefore separate between lock dog 52 and back-up block 42 as being slidably connected, between the two both can relative motion, also can move together.Separate lock dog 52 both sides, front and back vertically and be respectively equipped with the first solution lock section 523 and the second solution lock section 524, the first solution lock section 523 and second is separated lock section 524 and is set to inclined-plane or cambered surface, corresponding, on locating part 81, convex with abutting part 84, abutting part 84 is set to separate with the first solution lock section 523 and second inclined-plane or the cambered surface of lock section 524 butts, like this, by separating the axially-movable of lock dog 52, the first solution lock section 523 or second is separated lock section 524 and can be driven locating parts 81 move towards the direction separated with back-up block 42 by abutting part 84, the distance of separating relative sliding between lock dog 52 and back-up block 42 need to meet separate lock dog 52 move to make locating part 81 and back-up block divide 42 from position, that is to say, separating lock dog 52 move distance S makes locating part 81 separated with back-up block 42, the distance of separating relative sliding between lock dog 52 and back-up block 42 need to be more than or equal to S, separating so when lock dog 52 continues axially-movable just to drive back-up block 42 to move together.By the axially-movable of slide block 51, realized the locking of removing 81 pairs of output shaft 4 axially-movables of locating part, also realized the axially-movable of output shaft 4, convenient to operation.

Embodiment bis-

As shown in Figure 4, a kind of screwdriver is disclosed in the second embodiment of the present invention.This screwdriver is with the screwdriver in embodiment mono-, and it comprises casing 1, motor 2, transmission mechanism 3, output shaft 4 and battery 6.Transmission mechanism 3 is arranged between motor 2 and output shaft 4 and the rotary power of described motor 3 outputs can be passed to output shaft 4.

Difference is, the front end of output shaft 4 is also connected with magnetic keeper 44, and magnetic keeper 44 is directly connected with output shaft 4 front ends.Magnetic keeper 44 is ring set structure, and it comprises the link being connected with the front end of output shaft 4.Link be removably connected with the front end of output shaft 4.Link inner side is provided with internal thread, and the front end outer surface of output shaft 4 is provided with external screw thread, and magnetic keeper 44 is threaded connection with the front end of output shaft 4.Magnetic keeper 44 be threaded connection can work screwdriver bit 9 axially on flexible, can adjust the working space of work screwdriver bit 9.Certainly, link also can be connected by buckle with the front end of output shaft 4.Magnetic keeper 44 can be also non-dismountable being connected with the front end of output shaft 4, as being connected by binding agent.The front end end face of output shaft 4 also can be provided with accepting groove, and magnetic keeper 44 is housed in accepting groove.

The above-mentioned definition to each element is not limited in various concrete structures or the shape of mentioning in embodiment, and those of ordinary skill in the art can know simply and replace it.As motor can carry out instead of electr ic motor with gasoline engine or diesel engine etc.; Work screwdriver bit can be that cross section is regular arbitrarily polygon.In addition, position-limit mechanism is mainly used in limiting output shaft axially-movable, and to its structure and have no special requirements, the interior of visual different casings carrys out corresponding change configuration, can increase new element, also can reduce unnecessary element.

Claims (15)

1. a screwdriver, comprising:

Casing;

Motor, is arranged in casing, and outputting rotary power;

Output shaft, is driven by motor, has central axis, the front end of output shaft have axial setting for connecting the accepting hole of work screwdriver bit;

It is characterized in that: described output shaft can move axially and have in the axial direction along central axis the operating position of a plurality of output rotations, described screwdriver also comprises position-limit mechanism, described position-limit mechanism is for being limited in described output shaft operating position described in one of them, described screwdriver also comprises the magnetic keeper being connected with the front end of described output shaft, and described magnetic keeper is for helping the screw being driven by work screwdriver bit.

2. screwdriver as claimed in claim 1, is characterized in that: described screwdriver also comprises connector, and described magnetic keeper is connected with the front end of described output shaft by described connector.

3. screwdriver as claimed in claim 2, is characterized in that: described connector is the ring set structure with through hole, and described work screwdriver bit runs through described through hole; Described connector comprises first end and the second end, and described first end connects described magnetic keeper, and described the second end connects the front end of described output shaft.

4. screwdriver as claimed in claim 3, is characterized in that: described magnetic keeper is connected with the end face of described first end.

5. screwdriver as claimed in claim 4, is characterized in that: the end face of described first end is provided with accepting groove, and described magnetic keeper is contained in described accepting groove.

6. screwdriver as claimed in claim 3, is characterized in that: described the second end is removably connected with the front end of output shaft.

7. screwdriver as claimed in claim 6, is characterized in that: described the second end is provided with internal thread, and the front end of described output shaft is provided with external screw thread, and described connector is connected by described internal and external screw thread with the front end of described output shaft.

8. screwdriver as claimed in claim 6, is characterized in that: described connector is connected by buckle structure with the front end of described output shaft.

9. screwdriver as claimed in claim 2, is characterized in that: described connector is connected by adhesive with described output shaft.

10. screwdriver as claimed in claim 1, is characterized in that: described magnetic keeper is the ring set structure with through hole, and described work screwdriver bit runs through described through hole; Described magnetic keeper comprises the link being connected with the front end of described output shaft.

11. screwdrivers as claimed in claim 10, is characterized in that: described link is removably connected with the front end of described output shaft.

12. screwdrivers as claimed in claim 11, is characterized in that: described link is provided with internal thread, and the front end of described output shaft is provided with external screw thread, and described link is connected by described internal and external screw thread with the front end of described output shaft.

13. screwdrivers as claimed in claim 11, is characterized in that: described link is connected by buckle structure with the front end of described output shaft.

14. screwdrivers as claimed in claim 1, is characterized in that: described magnetic keeper is annular.

15. screwdrivers as claimed in claim 1, is characterized in that: described magnetic keeper is arranged on the front end end face of described output shaft.