CN102909676B

CN102909676B - Power tool

Info

Publication number: CN102909676B
Application number: CN201210204006.1A
Authority: CN
Inventors: 钟红风; 庞晓丽; 陈志�
Original assignee: Positec Power Tools Suzhou Co Ltd
Current assignee: Positec Power Tools Suzhou Co Ltd
Priority date: 2011-08-06
Filing date: 2012-06-20
Publication date: 2015-04-22
Anticipated expiration: 2032-06-20
Also published as: CN104801744B; CN102909710B; CN102909701B; CN102909702B; CN102909676A; CN104476472A; CN102909702A; CN104385205A; CN104476472B; CN202702198U; CN102909703B; CN102909710A; CN202702201U; CN104801744A; CN102909701A; CN102909703A; CN102909679A; CN102909678B; CN104385206B; CN102909678A

Abstract

The invention relates to a power tool, which comprises a shell, a motor which is arranged in the shell and outputs rotary power, an output shaft which is provided with an axially-arranged containing hole for containing a working head, a transmission mechanism which is arranged between the motor and the output shaft and transmits the rotary power output to the output shaft by the motor, a working head support mechanism which is arranged in the shell and is provided with a plurality of parallel-arranged containing spaces for supporting the working head, a connecting shaft which is arranged in the shell and capable of moving between two locations, wherein in a first location, the connecting shaft is connected with the working head and enables the working head to be located at a working location in the containing hole; in a second location, the connecting shaft enables the working head to be located at a containing location of the working head support mechanism and axially separated with the working head; a guide device is arranged adjacent to the working head support mechanism, the connecting shaft moves from the first location to the second location, and the working head is axially separated with the connecting shaft and kept at the containing location under the action of the guide device.

Description

Power tool

Technical field

The present invention relates to a kind of power tool, particularly relate to and a kind ofly realize the storage of working head and quick-replaceable drill gun class power tool.

Background technology

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

Electric screw driver be for by screw-driving to a kind of conventional electric tool on workpiece.In time needing the screw tightening different size in use procedure, change different working heads according to the difference of screw specification, namely screwdriver bit, namely the original working head installed will be taken off, then load onto the working head of another kind of structure.Under the use occasion needing frequent replacing working head, bring great inconvenience to operator, cause replacing working head on the one hand loaded down with trivial details, easy loss placed everywhere by the working head taken off on the other hand.Although, in some hand-operated tools, have some storage that can realize working head and quick-replaceables, due to the inherent defect of hand-operated tools, namely moment of torsion is little, and operation is hard, makes operator be easy to fatigue, cause inefficiency, be not suitable for using as the instrument of specialty in industrial sector.

Chinese utility model patent CN201086280Y discloses a kind of Multi-tool head electric tool, comprise power tool body and multi-knife-head rotaring wheel structure, multi-knife-head rotaring wheel structure comprises the multi-knife-head runner cylinder that can be accommodated multiple cutter head, multi-knife-head runner cylinder can be connected with tool body in axial sliding, when multi-knife-head runner cylinder slides into the position away from tool body, by rotating multi-knife-head runner cylinder thus the cutter head of selection needs.But when multi-knife-head runner cylinder is away from tool body, its connecting axle is exposed, the inside of electric tool inside or multi-knife-head runner cylinder is entered in the process that dust, powder can slide at multi-knife-head runner cylinder, time has been grown and multi-knife-head runner cylinder can have been caused to rotate carry out cutter head selection, or directly causes electric tool to use.And working head is against on workpiece when work, such connecting axle needs to bear reciprocal active force, connecting axle can bring pressure to transmission mechanism thus transmission mechanism can not be delivered to connecting axle moment of torsion, and such structure also makes the transmission of Multi-tool head electric tool unreliable.

And, if during operator's disable motor manual rotation cutter head, cutter head may be triggered and drive connecting axle rotation then to make motor rotation damage motor.

In addition, when changing cutter head, need first cutter head to be retracted into runner cylinder, when moving axially to prevent runner cylinder, cutter head is held by magnet and leaves from runner cylinder, Chinese utility model patent CN201086280Y is disclosed it and is thrown off to prevent cutter head and runner cylinder by the mode arranging retainer ring on cutter head, but such cutter head needs customized especially, makes the use of instrument not have versatility.And directly more unstable by connecting axle band dynamic cutter head speed ratio, because the length of connecting axle is longer, beating of connecting axle is larger, to the user of instrument with serving potential danger.Moreover, because runner cylinder needs to move axially to separate with connecting axle, be easy to enter dust and other impurities and cannot clean.

Summary of the invention

For the deficiencies in the prior art, the object of the present invention is to provide the power tool that a kind of reliable operation, cost are low.

The technical solution adopted for the present invention to solve the technical problems is: a kind of power tool, comprising: casing; Motor, is arranged in casing, and outputting rotary power; Output shaft, has the accepting hole of the accommodation working head axially arranged; Transmission mechanism, is arranged between motor and output shaft and also the rotary power that motor exports can be passed to output shaft; Working head supporting mechanism, be arranged in casing, described working head supporting mechanism has several receiving spaces be set up in parallel for support works head, and described working head supporting mechanism can be adjusted to one of them receiving space position axially corresponding with output shaft; Connecting axle, is arranged in casing, and described connecting axle can move between two positions, and in primary importance, described connecting axle and working head connect and working head be in be positioned at the operating position of accepting hole; In the second place, described connecting axle working head is in be positioned at working head supporting mechanism collecting position and can with working head axial separation; What described power tool also comprised that adjacent working head supporting mechanism arranges leads back to device, and described connecting axle moves from primary importance to the second place, and described working head remains on collecting position with connecting axle axial separation under the effect leading back to device.

Preferably, the described device that leads back to comprises the supporting surface contacted with working head supporting mechanism and the spigot surface be connected with supporting surface, and the adjustment of described working head supporting mechanism position can drive the working head engaged with connecting axle to be separated with connecting axle under the effect of spigot surface.

Preferably, described working head supporting mechanism and transmission mechanism are provided with cover plate, and described supporting surface and spigot surface are arranged on cover plate.

Preferably, the movement locus that described cover plate adjusts along working head along with working head supporting mechanism position is provided with step projection, and described supporting surface and spigot surface are arranged in step projection.

Preferably, on described cover plate, the position of corresponding connecting axle is provided with perforation, and described spigot surface is from the outside increasing height of perforation place.

Preferably, described spigot surface is provided with two, and two spigot surfaces to be positioned on movement locus that working head adjusts along with working head supporting mechanism position and to be distributed in perforation both sides.

Preferably, described spigot surface arranging for a week around described perforation.

Preferably, described spigot surface is inclined-plane.

Preferably, described inclined-plane is relative to storing the angle of inclination of folder end face between 10 degree to 30 degree.

Preferably, described working head supporting mechanism is rotatable is supported between casing and described cover plate.

Preferably, described connecting axle is connected between transmission mechanism and output shaft, and the rotary power that motor exports is passed to output shaft by described connecting axle by described transmission mechanism.

Compared with prior art, the invention has the beneficial effects as follows: power tool of the present invention makes connecting axle be separated with working head by simple structure, and working head is remained in working head supporting mechanism, ensure that higher reliability, reduce cost simultaneously.

Accompanying drawing explanation

Fig. 1 be the preferred power tool of the present invention in running order time sectional view.

Fig. 2 is the part isometric exploded view of Fig. 1 medium power instrument.

Fig. 3 is the cross-sectional schematic of Fig. 1 medium power instrument along E-E line.

Fig. 4 is the cross-sectional schematic of the another kind of embodiment of the pinion gear mechanism of Fig. 3 medium power instrument.

Fig. 5 is the sectional view that Fig. 1 medium power instrument is in when changing working head state.

Fig. 6 is the three-dimensional exploded view of the self-locking device part of Fig. 5 medium power instrument.

Fig. 7 is the sectional view along F-F direction in Fig. 5.

Fig. 8 is the using state reference diagram (now output planet carrier is rotated counterclockwise) of self-locking device in Fig. 7.

Fig. 9 is the using state reference diagram (now transfer panel turns clockwise) of self-locking device in Fig. 7.

Figure 10 is the schematic diagram of the first embodiment that Fig. 1 medium power tool changing working head limit working head retreats along with connecting axle.

Figure 11 is the schematic diagram that in Figure 10, block piece is in the position allowing connecting axle movement.

Figure 12 is the schematic diagram that in Figure 10, block piece is in the position that restriction working head retreats.

Figure 13 is the schematic diagram of the second embodiment that Fig. 1 medium power tool changing working head limit working head retreats along with connecting axle.

Figure 14 is the schematic diagram that in Figure 13, block piece is in the position allowing connecting axle movement.

Figure 15 is the schematic diagram that in Figure 13, block piece is in the position that restriction working head retreats.

Figure 16 is the schematic diagram of the 3rd embodiment that Fig. 1 medium power tool changing working head limit working head retreats along with connecting axle.

Figure 17 is the schematic diagram of the 4th embodiment that Fig. 1 medium power tool changing working head limit working head retreats along with connecting axle.

Figure 18 be in Figure 16 working head be limited along with connecting axle retreat operation principle schematic diagram, wherein connecting axle drive working head get back to store folder and connecting axle leave store folder.

Figure 19 and Figure 18 is similar, and wherein store folder and rotate, working head abuts with spigot surface.

Figure 20 and Figure 18 is similar, wherein store folder rotate, working head under the effect of spigot surface with connecting axle axial separation.

Wherein,

1. casing 2. motor 3. transmission mechanism

4. output shaft 6. battery 7. press button

9. working head 11. handle 13. fore shell

15. gathering sill 21. motor shaft 22. gear-boxes

30. pinion gear mechanism 31. planetary gear reducing mechanism 40. sleeves

41. accepting hole 50. fixed block 51. connecting axles

52. store folder 53. slip lid 54. steel cap

56.U type spring 57. shell fragment 81. limited block

131. perforate 133. opened portion 134. radial direction through hole

221. dividing plate 223. toothed wheel box cover plate 225. arched members

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

308. gear shaft 313. output planet carrier 321. fixed disks

322. transfer panel 323. roller 511. magnet

512. support ends 521. accommodate storehouse 522. pressing plate

523. opening 526.U type groove 531. guide rails

535. first projection 536. second projection 537. tread plates

571. elasticated end 2231., 2232. steps of boring a hole are protruding

2233. spigot surface 2233a. spigot surface 3181. plat parts

3131 legs 3211 fix pin 3212 inner headed face

3221 plane 3222 flat square hole 3223 spline tooth

Detailed description of the invention

In the preferred embodiment of power tool of the present invention, power tool is powered screwdriver, pneumatic screw driver can be divided into according to the difference of power source, surge screwdriver and electric screw driver, also have direct current and dividing of exchanging in electric screw driver, the present invention is preferably specifically described for DC electric screwdriver.

Shown in Fig. 3, this DC electric screwdriver comprises casing 1, motor 2, battery 6, transmission mechanism 3, connecting axle 51, working head supporting mechanism and output shaft 4.Casing 1 is closed up by symmetrical two and half housings assembled by screw (not shown), its have horizontal component and with horizontal component handle 11 part that arranges of K in obtuse angle, the preferred angle K of the present invention, can be pleasant when such gripping handle 11 operates between 100 degree to 130 degree.Be provided with press button 7 on the top of handle 11 part, battery 6 is fixed on the rear portion of handle 11 part, and transmission mechanism 3 is housed in the horizontal component of casing 1.As preferred embodiment, this battery 6 can be lithium ion battery.It should be noted that, here the general name of said lithium ion battery to be negative material the be rechargeable battery of elemental lithium, according to the difference of positive electrode, it can form many systems, as " lithium manganese " battery, and " lithium iron " battery etc.In the present embodiment, lithium ion battery to be a joint rated voltage be 3.6V(volt) lithium ion battery.Certainly, battery 6 also can be the battery types well known to those skilled in the art such as NI-G, ni-mh.

Transmission mechanism 3 comprises by (be rear with the right side of drawing) before backward the planetary gear reducing mechanism 31 and pinion gear mechanism 30 that are driven by motor 2, wherein pinion gear mechanism 30 is connected with connecting axle 51, and by connecting axle 51, the rotary motion of motor 2 is passed to output shaft 4.Wherein working head supporting mechanism is for storing different working heads, here working head mainly refers to Philip's head screw screwdriver bit, slot type screwdriver head, drill bit etc. that electric screw driver is conventional, move axially through working head supporting mechanism by operation connecting axle 51 or leave working head supporting mechanism, and adjust the position of working head supporting mechanism, just can quick-replaceable is different when electric screw driver is tightened or unclamped different screws working head.

According to the composition of above electric screw driver, electric screw driver can be divided into by (be rear with the right side of drawing) before backward the motor part D arranging motor successively, arranges the driving section C of transmission mechanism 3, arranges the storage part B storing folder and the efferent A arranging output shaft.

Motor 2 in the preferred embodiment for the present invention is motor, and motor has the motor shaft 21 extended forward from electric machine casing.Motor is fixed in casing 1, one gear-box 22 to be fixed in casing 1 and to be positioned at the front portion of motor, gear-box 22 is for accommodating planetary gear reducing mechanism 31 and pinion gear mechanism 30, by arranging dividing plate 221 between planetary gear reducing mechanism 31 and pinion gear mechanism 30, the two is separated, and toothed wheel box cover plate 223 is set between gear-box 22 and working head supporting mechanism, transmission mechanism 3 and working head supporting mechanism can be separated like this, namely transmission mechanism 3 and working head supporting mechanism are separate.Pinion gear mechanism 30 comprises can the first gear 301 of being connected of transmitting torque by a gear shaft 308 with planetary gear reducing mechanism 31, the 3rd gear 303 be connected with connecting axle 51 and the second gear 302 simultaneously engaged with the first gear 301 and the 3rd gear 303, wherein gear shaft 308 can be wholely set with the first gear 301, the rotation of the first gear 301 is passed to the 3rd gear 303 by the second gear 302, and the two ends of each gear are supported by axle sleeve.The middle part of dividing plate 221 is provided with the hole supplying the axle of the first gear 301 to pass, the end face of dividing plate 221 is provided with the groove for installing axle sleeve, the rear axle housing supporting pinion gear mechanism 30 is fixed on dividing plate 221, front shaft sleeve is fixed on toothed wheel box cover plate 223, toothed wheel box cover plate 223 and gear-box 22 are fixedly linked by screw, buckle etc., so, namely pinion gear mechanism 30 and planetary gear reducing mechanism 31 can be separated, both can be closed again simultaneously, prevent dust, powder etc. from entering transmission mechanism 3 inner, also can prevent the leakage of lubricating oil.

With reference to Fig. 3, first gear 301, the center line of the second gear 302 and the 3rd gear 303 is arranged on same straight line, in order to make transmission more steady, the gearratio being transferred to the 3rd gear 303 from the first gear 301 is 1:1, can be the first gear 301 to the second gear 302 be like this step-up drive, second gear 302 to the three gear 303 is deceleration transmission, reference diameter as the first gear 301 and the 3rd gear 303 is equal, the reference diameter of the second gear 302 is less than the reference diameter of the first gear 301 and the 3rd gear 303, optimal location when can ensure that three gear centres are coaxial is so set, the space taken is minimum.If but when electric screw driver is more miniaturized, less may the needs that the second gear 302 is arranged arranges the less number of teeth, causes the number of teeth engaged between gear to tail off simultaneously, transmission intensity declines and makes transmission unstable.As cancelled the second gear 302, first gear 301 and the 3rd gear 303 are arranged to direct engagement, also can transmit motion, but the diameter of the first gear 301 and the 3rd gear 303 must be increased like this, and the volume that certainly will increase more greatly electric screw driver that the first gear 301, the 3rd gear 303 are arranged.For this reason, with reference to Fig. 4, can by the pivot line eccentric setting of the second gear 302 relative to the first gear 301 and the 3rd gear 303, so both ensure that the size of the second gear 302 can not be too small, the size in three gear laid out in parallel directions also can not be excessive simultaneously, can ensure that the gearratio between three gears is more steady, between preferred eccentric size L is 0.1 times to 0.3 times of the first gear 301 reference diameter, between the reference diameter of other first gear 301 is 1.1 to 1.5 times of the reference diameter of the second gear 302, ensure that between three gears, bearing capacity is higher, and efficiency is high, life-span is long.In addition, three gears are set the inner space of instrument can be made compacter, thus do not affect the attractive in appearance of outside.

Certainly, also can be arranged to two gears as required, one is connected with planetary gear reducing mechanism 31, and another is connected with connecting axle 51.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 30, or other rotary motion transmission mechanism, as ratchet mechanism, turbine mechanism etc.Wherein planetary gear reducing mechanism 31 has three grades of deceleration systems, motor shaft 21 extension is engaged with planetary gear reducing mechanism 31, rotary motion is passed to pinion gear mechanism 30 by planetary gear reducing mechanism 31, and pinion gear mechanism 30 drives connecting axle 51 to rotate, and connecting axle 51 again driver output axle rotates.When such motor 2 runs, by planetary gear reducing mechanism 31, pinion gear mechanism 30, finally exported by output shaft 4.This shows, the driving-chain in present embodiment is motor-transmission mechanism-connecting axle-output shaft, and namely connecting axle is as a part for driving-chain.In addition, reducing gear is made up of three stage planetary reduction and two-stage parallel axis deceleration system and obtains wanted output speed, in other embodiments, depending on the required rotating speed exported, reducing gear can only include two-stage planetary reduction system, or other deceleration systems.

With reference to shown in Fig. 5, Fig. 6, Fig. 7, planetary gear reducing mechanism 31 comprises output planet carrier 313.Electric screw driver is provided with self-locking device between planetary gear reducing mechanism 31 and pinion gear mechanism 30, self-locking device comprises a fixed disk 321, several fixing pins 3211 are evenly provided with in the periphery of fixed disk 321, these fixing pins 3211 are integrated with gear-box 22 compact siro spinning technology, make fixed disk 321 be inactive state relative to casing 1 and gear-box 22, be then formed with inner headed face 3212 in the inside circumference of fixed disk 321.In the scope of inner headed face 3212, be provided with a transfer panel 322, the core of transfer panel 322 arranges flat square hole 3222.Gear shaft 308 one end connects the first gear 301, the other end is arranged to plat part 3181, and transfer panel 322 and gear shaft 308 are connected as one by flat square hole 3222 and plat part 3181, thus can rotate together with gear shaft 308.Wherein adopted connected mode can be that the spline joint that those skilled in that art are usual and other connected mode easily expected are replaced.Self-locking device also comprises from the end face of the output planet carrier 313 multiple legs 3131 outstanding to the first gear 301 direction, and leg 3131 is fixedly installed on output planet carrier 313.

The periphery of transfer panel 322 is formed with multiple plane 3221, and the one end near output planet carrier 313 on transfer panel 322 is provided with connecting portion, and this connecting portion adopts spline tooth 3223, and transfer panel 322 is by spline tooth 3223 and output planet carrier 313 loose fit.Between fixed disk 321 and transfer panel 322, position is respectively equipped with roller 323 between the inner headed face 3212 of fixed disk 321 and the plane 3221 of transfer panel 322 more specifically, and roller 323 against inner headed face 3212 and plane 3221, and can roll on present position.In addition, be inserted with the leg 3131 of output planet carrier 313 between each roller 323, that is, leg 3131 is arranged between the inner headed face 3212 of fixed disk 321 and the outside disc of transfer panel 322.Inner headed face 3212 and the transfer panel 322 of leg 3131 and fixed disk 321 are matched in clearance, and therefore leg 3131 can around the center rotating of transfer panel 322.

With further reference to Fig. 8, when trigger button switch 7, exporting for the rotation of motor 2 is counterclockwise, the rotation torque that motor 2 produces is delivered on output planet carrier 313, output planet carrier 313 relatively and the transfer panel 322 that connects of its spline turn over certain angle, now the leg 3131 of output planet carrier produces the rotation in respective direction with output planet carrier 313.Wherein, after leg 3131 rotates one section of micro-displacement, be resisted against on roller 323, because roller 323 is that the small end in the face of carving formed between both planes 3221 by inner headed face 3212, transfer panel 322 is to large end motion, roller 323 promotes so can be output end planet carrier leg 3131, follow output planet carrier 313 to rotate, until spline tooth 3223 contacts side surfaces of output planet carrier 313 and transfer panel 322, now the leg 3131 of output planet carrier drives together with transfer panel 322 with roller 323 and rotates.Like this, the rotation torque of motor 2 will be delivered on the gear shaft 308 that is fixedly connected with transfer panel 322, and be delivered to the first gear 301 further, be delivered on output shaft 4 by the second gear 302, the 3rd gear 303 and connecting axle 51, thus output shaft 4 drives working head 9 to rotate.

With further reference to Fig. 9, when press button 7 disconnects, motor 2 stops the rotation and moment of torsion output without spin.Now, no matter operator turns output shaft 4 or is contained in the working head 9 in output shaft 4 along clockwise direction or counterclockwise, what show will be that gear shaft 308 can along with the small rotation producing respective direction, because gear shaft 308 and transfer panel 322 are connected as one by flat side, the rotation that transfer panel 322 also will produce with gear shaft 308 in respective direction.And roller 323 is rolled into position shown in solid line by the position shown in dotted line, because roller 323 is that the large end in the face of carving formed between both planes 3221 by inner headed face 3212, transfer panel 322 is to little end motion, now fixed disk 321 plane 3221, mutually carve between inner headed face 3212 and plane 3221 three of transfer panel 322 tight, gear shaft 308 can not drive output planet carrier support 41 to rotate, namely gear shaft 308 automatically locks, and that is rotary motion cannot be delivered to output planet carrier 313 from output shaft 4.Due to the setting of self-locking structure, make operator that manual rotation electric screw driver can be selected to twist screw.Be particularly useful for when electric screw driver is under electric model, screw is screwed onto when substantially putting in place, by press button 7, motor 2 is stopped, under manual mode, rotate this electric screw driver and screw is screwed to position, thus avoid screw and cross under electric model and twist and cause the sliding tooth of screw.This electric screw driver can be described as the screwdriver of a hand, electric integral, easy to operate and be easy to carry.

In above-mentioned embodiment, self-locking device is arranged between planetary gear reducing mechanism 31 and pinion gear mechanism 30, those skilled in the art are easy to expect that self-locking device other positions be arranged between motor 2 and output shaft 4 also can realize the single-direction transmission of motor 2 to output shaft 4, as between motor 2 and planetary gear reducing mechanism 31, between pinion gear mechanism 30 and between connecting axle 51 etc.The version of self-locking device is also not limited to above-mentioned embodiment, and any self-locking device that can realize single-direction transmission can be applied on the preferred electric screw driver of the present invention.

Casing 1 is slidably connected with slip lid 53, and slip lid 53 can drive connecting axle 51 to move axially.The edge of slip lid 53 is provided with guide rail 531, and corresponding casing 1 is provided with gathering sill 15, and slip lid 53 is arranged in gathering sill 15 can be slid axially relative to casing 1 by its guide rail 531.Certainly, also can be that slip lid 53 arranges gathering sill, mode casing 1 being arranged guide rail makes slip lid 53 move.

The cross section of conventional standard operation head shank is orthohexagonal, namely shank is formed as the moment of torsion forced section of working head, and output shaft 4 has the accepting hole 41 axially run through, accepting hole 41 is arranged to the form of the hexagonal hole matched with the moment of torsion forced section of working head, in it, installment work head makes working head be in operating position, thus realizes the transmission of moment of torsion.Certainly, working head also can the criteria of right and wrong, and namely the cross section of moment of torsion forced section is polygonal shape, corresponding accepting hole is arranged to the polygon matched with moment of torsion forced section, can realize the transmission of moment of torsion.Output shaft 4 is supported in the axial aperture 131 of fore shell 13 by an axle sleeve 40, and axle sleeve 40 provides radial support to output shaft 4, can certainly be realized the radial support of output shaft 4 by bearing.Connecting axle 51 of the present invention is also hexagon, hexagonal hole is provided with in 3rd gear 303, for connecting with connecting axle 51 and rotary power being passed to connecting axle 51, such connecting axle 51 inserts output shaft 4 and output shaft 4 can be driven to rotate, and then drive working head 9 to rotate by output shaft 4, the working head 9 of standard can be used like this, and without the need to offering the hole of collecting working head 9 on connecting axle 51, avoid the weight and volume of the excessive increase complete machine of connecting axle 51 diameter.Like this, what directly drive working head 9 to rotate is output shaft, shorten the distance of torque transfer, thus the use of instrument is more reliable.Above-described is that connecting axle moves the mode of working head rotation by output shaft indirect belt, but, those skilled in the art are easy to expect that other transmission means substitutes, such as connecting axle directly drives working head to rotate, namely connecting axle directly with working head can the mode of transmitting torque be connected, or output shaft is driven by direct geared, and connecting axle only stores folder for releasing working head and driving working head to get back to, that is driving-chain is motor-transmission mechanism-output shaft, and namely connecting axle is not as a part for driving-chain.

With reference to shown in Fig. 1, Fig. 2, Fig. 5 and Fig. 6, connecting axle 51 is six square shafts, on connecting axle 51 axial restraint be provided with a fixed block 50, slip lid 53 drives connecting axle 51 to move by the mode be connected with fixed block 50.The inside of slip lid 53 is provided with the first projection 535 and the second projection 536 along connecting axle 51 axially spaced-apart, in the duty of electric screw driver, first projection 535 has distance S with fixed block 50 axially spaced-apart, when slip lid 53 slides backward, namely slide in the direction towards motor 2, after the distance S that slided, the first projection 535 axially abuts with fixed block 50, thus slip lid 53 drives fixed block 50 then to drive connecting axle 51 axially to move backward, otherwise the second projection 536 drives connecting axle 51 axially to move forward.In addition, electric screw driver needs working head 9 to be axially pressed on screw or workpiece when operating, such work 9 can be subject to a reverse responsive to axial force, move after producing connecting axle 51, the limited block 81 compressed by elasticity is set in present embodiment on casing 1, limited block 81 can move between two positions abutting and be separated with fixed block 50, to realize the axially-movable limiting and allow connecting axle 51.

Fixed block 50 is the shape of cubic hollow, connecting axle 51 has the support end 512 of connection fixing block 50, support end 512 is arranged to cylindrical, one side of fixed block 50 is provided with circular hole or U-shaped hole, support end 512 by circular hole, U-shaped hole is rotating is supported on fixed block 50, the hollow space that support end 512 extend into fixed block 50 can arrange annular groove thus can assemble back-up ring with to connecting axle 51 move axially carry out spacing.The diameter of support end 512 is preferably less than the external diameter of a circle of connecting axle 51 6 side, can reduce the volume of fixed block 50 like this thus make the structure of instrument entirety compacter.Another side relative with circular hole or U-shaped hole on fixed block 50 and the end of support end 512 offset, wherein the end of support end 512 is arranged to coniform, such connecting axle 51 is point cantact with the contact of fixed block 50, because electric screw driver needs working head 9 to be axially pressed on workpiece when operating, such working head 9 can be subject to a reverse responsive to axial force, this axial force can pass to connecting axle 51, larger stressed friction will be produced between connecting axle 51 and fixed block 50, the mode of point cantact can reduce friction, increase the service life of connecting axle 51.In addition, connecting axle 51 and fixed block 50 can be made all to adopt metal to make, reduce the degree of wear between connecting axle 51 and fixed block 50.And fixed block 50 can be connected by the shape of multiple cubic hollow, to gain in strength, as preferably adopted the shape of two or three cubic hollows in present embodiment.Arrange the advantage that fixed block 50 can also have other, such as connecting axle 51 is rotatable to be supported on fixed block 50, without the need to using bearings, reduces volume and the cost of instrument; The sidepiece area of fixed block 50 is large, facilitates limited block 81 and fixed block 50 to offset with to connecting axle 51 axial limiting, also facilitates slip lid 53 to drive connecting axle 51 to move by the mode offseted with fixed block 50; The hollow space of fixed block 50 also can play slip lid 53 and have idle stroke (i.e. slip lid 53 move and connecting axle 51 does not move thereupon) relative to connecting axle 51, such slip lid 53 only need be arranged a projection just can drive connecting axle 51 to move forward and backward, thus facilitates slip lid 53 to operate limited block 81 to carry out the locking and unlocking to connecting axle 51.

In addition, those skilled in the art are easy to expect, if the driving-chain of powered screwdriver does not comprise connecting axle, namely output shaft is rotated by pinion gear mechanism Direct driver, so just have relative rotation between working head and connecting axle, friction will inevitably be produced, as long as so arrange at connecting axle the form being arranged to point cantact between the working end of magnet and working head also can reduce friction, the service life of tool for increasing.

Certainly, it is a lot of that slip lid 53 drives the mode of connecting axle 51 movement to also have, as the annular groove around its outer week Monday can be arranged on connecting axle 51, slip lid 53 is extend in annular groove by a pin or steel wire ring and is connected with connecting axle 51, so neither affect the rotation of connecting axle 51, also do not affect the movement that slip lid 53 drives connecting axle 51.The front end of connecting axle 51 is provided with magnet 511, for adsorbing working head 9, when selecting good berth head 9, can operate slip lid 53 drives connecting axle 51 through working head supporting mechanism, the magnet 511 that working head 9 is connected on axle 51 adsorbs, and under the promotion of connecting axle 51, leave working head supporting mechanism, enter output shaft 4.

Casing 1 comprises the fore shell 13 being connected to its front end, and a part for working head supporting mechanism is housed in fore shell 13, and another part is covered along with moving of slip lid 53 by slip lid 53 and exposes.The preferred working head supporting mechanism of the present invention is cylindric storage folder 52, conveniently rotates, and takes up room little simultaneously, can certainly be arranged to square, leg-of-mutton, strip, shelf-like etc.When electric screw driver work, slip lid 53 abuts with fore shell 13, storage folder 52 all can be closed with connecting axle 51 like this.On toothed wheel box cover plate 223, the position of corresponding connecting axle 51 is provided with the hole passed for connecting axle 51, gear-box 22 there is arched member 225 around connecting axle 51 Axis Extension, arched member 225 can be wholely set with gear-box 22, also can be provided separately, can by partially enclosed for connecting axle 51 by arranging arched member 225, when electric screw driver carries out change working head 9, namely the position that slip lid 53 moves to rearmost end also out exposed for connecting axle 51, can not can prevent the inside of the entering tool such as dust, powder like this.And toothed wheel box cover plate 223 extends to the end face of arched member 225, thus vertically by transmission mechanism 3 integrally closed together.In the course of the work, storage folder can be closed by slip lid 53, thus prevent dust from entering, when working head changed by needs, remove slip lid 53 and can expose storage folder 52, the working head that convenient selection is different, slip lid 53 is so just needed to have certain length, when slip lid 53 moves to the operating position abutted with fore shell 13, slip lid 53 and storage part B and driving section C axial overlap, when slip lid 53 moves to the position of replaceable working head, slip lid 53 and motor part D axial overlap, and with driving section C part axial overlap.Certainly, the mode of slip lid 53 movement also has a lot, and such as slip lid 53 is rotatable to be installed on casing 1, rotates between two positions that covering stores folder 52 and exposes storage folder 52; Or be similar to the mode of sliding door, can open or close; Or pivotable be connected to mode of casing 1 etc., when can realize work, storage folder 52 is closed, need change working head time storage folder 52 is exposed.

The top of fore shell 13 is provided with opened portion 133, the bottom of fore shell 13 is provided with and opened portion 133 radial aperture 134 diametrically, operation slip lid 53 moves to the direction of motor 2, connecting axle 51 is also along with slip lid 53 moves to and the position storing folder 52 and separate, direct like this being reached by finger in radial aperture 134 just can eject storage folder 52 and remove from opened portion 133, then storage another one being provided with different working heads is pressed from both sides and loaded casing from opened portion 133 and just can use.

Store that folder 52 is rotatable is supported between toothed wheel box cover plate 223 and output shaft 4, store on folder 52 and be evenly distributed with multiple working head collecting storehouse 521 along its circumferencial direction, that is working head has multiple receiving space, and multiple receiving space is set up in parallel along the rotation storing folder 52.Working head collecting storehouse 521 is closed along storage folder 52 is axially a part of, and a part of excircle opens wide, and such handled easily person selects the shape that can be easy to see from the part of opening wide working head 9 head during working head 9, thus selects the working head 9 of needs fast.Certainly, those skilled in the art are easy to expect, working head collecting storehouse 521 also can be totally enclosed, only need identify in the position of correspondence, or directly makes transparent by storage folder 52, can conveniently identify.In addition, elasticity location can be carried out between storage folder 52 and toothed wheel box cover plate 223, namely on the end face storing toothed wheel box cover plate 223 faced by folder 52, the position of corresponding working head 9 arranges locating slot 522, locating slot 522 is corresponding with collecting storehouse 521, toothed wheel box cover plate 223 is arranged the steel cap compressed by spring, or shell fragment, so, storage folder often turns over a working head 9 steel cap or shell fragment all can send the voice prompt falling into locating slot 522, thus the angle that operator selects to avoid storage 52 to press from both sides during working head 9 to rotate and connecting axle 51 stagger.

When the work of needs electric screw driver, connecting axle 51 moves forward under the drive of slip lid 53, the working head promoting to have selected enters output shaft 4, when working head changed by needs, connecting axle 51 retreats under the drive of slip lid 53, because one end that connecting axle 51 contacts with working head is provided with magnet 511, store in the collecting storehouse 521 of folder so connecting axle 51 can drive working head to get back to working head.And if connecting axle 51 continue after move, can drive working head from collecting storehouse 521 in out, cause changing working head, if operator do not find and rotate store folder time, probably cause the damage of instrument.The present invention proposes four kinds of solutions for addressing this problem, and is described respectively below.

With reference to shown in Fig. 2 and Figure 10 to Figure 12, it is the first embodiment that restriction working head 9 retreats along with connecting axle 51.Store folder 52 and be provided with pressing plate 522 in the face of one end of gear-box 22, pressing plate 522 can rotate together along with storage folder 52, and pressing plate 522 can be arranged with storage folder 52 integral type, also can be provided separately, present embodiment is preferably provided separately, and both convenient processing, also easily assembled.The position in pressing plate 522 correspondence collecting storehouse 521 is provided with opening 523, for passing connecting axle 51, on the end face storing folder, U-type groove 526 is provided with at opening 523, for accommodating U-shaped spring 56, U-shaped spring 56 has part to be overlapping with opening 523 when free state, the design of U-type groove 526 is reserved with space to the elastic deformation of U-shaped spring 56.Because the quantity that the present invention preferably accommodates storehouse 521 is 6, corresponding opening 523 quantity is also 6, the quantity of U-type groove 526 and U-shaped spring 56 is similarly 6, certain those skilled in the art are easy to expect, opening 523, U-type groove 526 and U-shaped spring 56 also can only arrange one, namely pressing plate 522 is fixedly installed relative to gear-box 22, and what such connecting axle 51 passed at every turn is same opening 523, can not affect to rotate to store folder 52 to select working head.When connecting axle 51 retreats and moves backward with working head under the effect of magnet 511, U-shaped spring 56 can elastic deformation be stuck on connecting axle 51, and namely U-shaped spring 56 is in the primary importance (with reference to Figure 13) allowing connecting axle 51 to move.Because the end that connecting axle 51 connects working head is connected connecting axle 51 end with working head all has chamfering or rounding, when the opening 523 of pressing plate 522 is left in the end that connecting axle 51 connects working head 9, free state replied by U-shaped spring 56, the part of opening 522 is blocked, working head 9 is stopped by U-shaped spring 56 along with when connecting axle 51 continues retrogressing, and namely U-shaped spring 56 is in the second place (with reference to Figure 14) that restriction working head 9 retreats.Such connecting axle 51 separates with working head 9, can rotate arbitrarily and store folder to select another working head 9 needed.When powered screwdriver work, resistance is caused to the rotation of connecting axle 51 in order to prevent U-shaped spring 56, can arrange around the connecting axle annular groove of 51 1 weeks 512 position of axial corresponding U-shaped spring 56 on connecting axle 51, U-shaped like this spring 56 can not cause resistance to the rotation of connecting axle 51, and U-shaped spring 56 achieves and led back in storage folder 52 by working head simultaneously.

With reference to shown in Figure 13 to Figure 15, it is the second embodiment that restriction working head 9 retreats along with connecting axle 51.Toothed wheel box cover plate 223 is fixed with a shell fragment 57, shell fragment 57 is arranged on and stores between folder 52 and toothed wheel box cover plate 223, shell fragment 57 is provided with at least one elasticated end 571, elasticated end 571 part stretches in the hole on toothed wheel box cover plate 223, like this by the elastic deformation of elasticated end 571, also can realize blocking working head 9, drive working head 9 to leave when preventing connecting axle 51 from retreating and store folder 52.With reference to Figure 14, elasticated end 571 is in the primary importance allowing connecting axle 51 to move; With reference to Figure 15, elasticated end 571 is in the second place that restriction working head 9 retreats.According to the present embodiment, those skilled in the art are easy to expect, can directly elasticated end 571 be stuck on toothed wheel box cover plate 223, or the stator of rigidity is set, stator is by the hole of elastic reaction on partial occlusion toothed wheel box cover plate 223 and leave on toothed wheel box cover plate 223 between Liang Ge position, hole to move, thus the separation realized between working head 9 and connecting axle 51 and working head 9 is led back to store folder 52.

With reference to shown in Figure 16, it is the third embodiment that restriction working head retreats along with connecting axle.On toothed wheel box cover plate 223, the position of corresponding connecting axle 51 is provided with perforation 2231, the end face that toothed wheel box cover plate 223 is adjacent with storing folder 52 is provided with step projection 2232, step projection 2232 is around storing the pivot of folder 52 and corresponding collecting storehouse 521 is arranged, step projection 2232 disconnects at perforation 2231 place, and part step projection 2232 being positioned at perforation both sides arranges spigot surface 2233, spigot surface 2233 along working head along with store folder rotate direction on from perforation 2231 place's increasing height, that is spigot surface 2233 bores a hole 2231 places certainly to both sides increasing height, material is thus formed two spigot surfaces, no matter storage folder 52 rotates forward or reverses can be led to the position of working head.

With reference to shown in Figure 17, be the 4th kind of embodiment that restriction working head retreats along with connecting axle.Spigot surface 2233a is directly arranged on the end face of toothed wheel box cover plate 223, spigot surface 2233a is arranged around perforation 2231, from the outside increasing height in perforation 2231 place, the spigot surface 2233a that such formation one is annular, is not only beneficial to processing but also can ensure can both lead to the position of working head when storing folder rotating.

As above 3rd, in 4th embodiment mask work head and connecting axle 51 and working head 9 is led back to store folder 52 time, spigot surface role is identical, for the 3rd embodiment, shown in action principle reference Figure 18 to Figure 20 that spigot surface 2233 is concrete, when working head changed by needs, operation slip lid 53 drives connecting axle 51 to move to connecting axle 51 and is axially separated with storage folder 52 (namely axially not overlapping), still engage with connecting axle 51 under the suction of working head magnet 511 on connecting axle 51 and have part to exceed the end face storing folder 52, rotate and store folder 52, working head is subjected to displacement along with storing folder 52 and abuts with spigot surface 2233, such continuation rotates and stores folder 52, working head 9 will be concordant with the end face storing folder 52 to the end face of working head 9 in the effect lower slider of spigot surface 2233, the rotation storing folder 52 can not be had influence on.

Although, if set the stroke that connecting axle 51 moves and the dimensional accuracy storing folder 52 and tool interior structure, assembly precision, the position that the end face that connecting axle 51 can only drive working head 9 to move to working head is concordant with the end face storing folder 52, also can rotate normally and store folder 52, but such words has very high requirement to the machining accuracy of parts and assembly precision, the cost of electric screw driver certainly will be increased, and constantly rub along with in use, size between parts produces error, still can there is working head 9 to block and store folder 52 or connecting axle 51 and block and store folder 52 and cause storing folder 52 and can not normally rotate.Also can think by the accuracy of manufacture, the impact of rocking the composite factor such as gap, material, working head and toothed wheel box cover plate 223, connecting axle 51 may be interfered in rotary course with storage folder 52.Very large leeway can be left to the movement of connecting axle 51 by arranging spigot surface, thus improve the geometry coordinating position place, eliminate and store the possibility that in folder 52 rotary course, each materials and parts are interfered.So just do not need very high manufacture and assembly precision, just can reduce costs greatly, and storage folder 52 is not easy to be stuck thus can increases the service life of instrument.

According to the motion principle between working head 9 and spigot surface 2233, spigot surface 2233 can be inclined-plane, curvilinear plane, arcwall face etc., preferred inclined-plane in present embodiment, inclined-plane is α relative to the angle of inclination of storage folder 52 end face, the leeway of connecting axle 51 movement is roughly chamfer length and is multiplied by sin α, therefore the leeway of angle [alpha] larger connecting axle 51 movement is just corresponding larger, rotate that to store folder 52 also larger to drive working head 9 to move the power of needs along inclined-plane simultaneously, in order to make to compare balance between the two, the tilt angle alpha on preferred inclined-plane is between 10 degree of-30 degree, such rotation stores folder 52 neither needs the strength that costs a lot of money, ensure that connecting axle 51 has enough mobile leeway simultaneously.

The above-mentioned definition to each element is not limited in the various concrete structure or shape mentioned in embodiment, and those of ordinary skill in the art can replace it with knowing simply.As motor can carry out alternative motor with gasoline engine or diesel engine etc.; Working head can be cross section is arbitrary regular polygon; In addition, in above-mentioned embodiment, moving to axial between connecting axle and working head store and press from both sides also can be that connecting axle is fixed, and working head storage folder can either also can rotate in axially-movable, and connecting axle also can be coaxially arrange with motor shaft, have no special requirements to its structure, visual different interior carrys out corresponding change configuration, new element can be increased, also can reduce unnecessary element.

Claims

1. a power tool, comprising:

Casing;

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

Output shaft, has the accepting hole of the accommodation working head axially arranged;

Transmission mechanism, is arranged between motor and output shaft and also the rotary power that motor exports can be passed to output shaft;

Working head supporting mechanism, be arranged in casing, described working head supporting mechanism has several receiving spaces be set up in parallel for support works head, and described working head supporting mechanism can be adjusted to one of them receiving space position axially corresponding with output shaft;

Connecting axle, is arranged in casing, and described connecting axle can move between two positions, and in primary importance, described connecting axle and working head connect and working head be in be positioned at the operating position of accepting hole; In the second place, described connecting axle working head is in be positioned at working head supporting mechanism collecting position and can with working head axial separation;

It is characterized in that: described power tool also comprise adjacent working head supporting mechanism arrange lead back to device, the described device that leads back to comprises the supporting surface contacted with working head supporting mechanism and the spigot surface be connected with supporting surface, described connecting axle moves from primary importance to the second place, and the adjustment of described working head supporting mechanism position can drive the working head engaged with connecting axle be separated with connecting axle under the effect of spigot surface and remain on collecting position.

2. power tool as claimed in claim 1, is characterized in that: described working head supporting mechanism and transmission mechanism are provided with cover plate, and described supporting surface and spigot surface are arranged on cover plate.

3. power tool as claimed in claim 2, is characterized in that: the movement locus that described cover plate adjusts along working head along with working head supporting mechanism position is provided with step projection, and described supporting surface and spigot surface are arranged in step projection.

4. power tool as claimed in claim 2, it is characterized in that: on described cover plate, the position of corresponding connecting axle is provided with perforation, described spigot surface is from the outside increasing height of perforation place.

5. power tool as claimed in claim 4, is characterized in that: described spigot surface is provided with two, and two spigot surfaces to be positioned on movement locus that working head adjust along with working head supporting mechanism position and to be distributed in both sides of boring a hole.

6. power tool as claimed in claim 4, is characterized in that: described spigot surface arranging for a week around described perforation.

7. power tool as claimed in claim 1, is characterized in that: described spigot surface is inclined-plane.

8. power tool as claimed in claim 7, is characterized in that: described inclined-plane is relative to storing the angle of inclination of folder end face between 10 degree to 30 degree.

9. power tool as claimed in claim 2, is characterized in that: described working head supporting mechanism is rotatable to be supported between casing and described cover plate.