CN107344349A

CN107344349A - Electric tool

Info

Publication number: CN107344349A
Application number: CN201610300260.XA
Authority: CN
Inventors: 郑祥格; 汪亮
Original assignee: Bosch Power Tools China Co Ltd
Current assignee: Bosch Power Tools China Co Ltd
Priority date: 2016-05-06
Filing date: 2016-05-06
Publication date: 2017-11-14
Anticipated expiration: 2036-05-06
Also published as: DE102017207520A1; CN107344349B

Abstract

The invention provides a kind of electric tool, at least has the first mode of operation of output rotary motion and does not export the second mode of operation of rotary motion, including drive part；Rotate output par, c；The rotary motion of drive part is passed into rotation output par, c makes it export the running part of rotational motion；Clutch system, it has engagement state corresponding with the first and second mode of operations and disengaged condition, and it is constructed such that to be converted to disengaged condition automatically in an irreversible fashion from engagement state when the electric tool in the first mode of operation meets with and exceedes drag torque, electric tool is transformed into the second mode of operation；Switching system, it has the first gear corresponding with the first and second mode of operations and the second gear；And the coupling part engaged with both clutch system and switching system, it, which is configured to the triggering switching system when clutch system is converted to disengaged condition from engagement state, makes it automatically be changed from the first gear to the second gear.

Description

Electric tool

Technical field

The present invention relates to a kind of novel electric instrument, the electric tool can be hammer drill and/or pricker hammer.

Background technology

As known in the art, electric tool, such as hammer drill can have three mode of operations：Impact Drilling, drilling and chisel pricker.In percussive drilling pattern, drill bit is revolved under the driving of motor simultaneously Turn (drilling) and impact (chisel is hit) action；In drill mode, drill bit only carry out spinning movement and Without percussion action；And in pricker pattern is dug, drill bit only carry out percussion action and without rotation Action.

For most hammer drills, all including motor, the drive sleeve driven by motor, On the one hand drive sleeve drives beater mechanism to carry out reciprocating impact action by driving bearing, on the other hand The bit retainer on hammer pipe and hammer pipe is driven to be driven sometimes to carry out spinning movement via jackshaft Dynamic sleeve pipe, driving bearing, jackshaft and their other annexes are referred to as transmission device.

Because this electric tool generally operates on the materials such as concrete, fragment of brick or slabstone, so making The situation that the drill bit of hammer drill snaps on these materials suddenly is would ordinarily be encountered during, now drill bit meets with Huge resistance is met, the destruction torque beyond hammer drill breakdown torque is produced, to operator, to electronic work Tool all has very big dangerous and destructive in itself.

There is a kind of electric tool in the prior art, it is provided with hammer pipe prevents from destroying torque in Countershaft, drive sleeve are delivered to the structure with operator.This structure is mainly bonded with each other including two Part, first component and second component include being mutually clamped prominent respectively on surface facing with each other Rise and recess, when projection and recess on first component and second component engage, jackshaft driving hammer Pipe makes its rotation, when drill bit meets with large drag forces, destroys torque and overcomes facing between projection and recess Boundary's torque, is disengaged both, so as to interrupt jackshaft and hammer the engagement of pipe into shape, reaches protection operation The purpose of person.

However, because motor is still operating, repeated always between first component and second component The action disengage, engaged, disengage again, rejoin ..., until operator turns off motor.In motor Before being switched off, the destruction torque for the torque that oversteps the extreme limit constantly can be transferred to operation by the structure Person, still suffer from the danger of injury operator.In addition, disengagement and joint action are repeated continuously, can be big The big service life for shortening related components, so as to destroy electric tool in itself.

Want to improve the structure of this electric tool so that in these cases can automatically, The transmission of the rotary motion between motor and drill bit is for good and all interrupted, torque is avoided damage to and is delivered to Operator.

The content of the invention

Clutch system, switching system are included and positioned at company between the two according to the electric tool of the present invention Socket part point.When electric tool meets with large drag forces, clutch system disengages automatically from engagement state, makes The first mode of operation that electric tool rotates from output is switched to the second mode of operation for not exporting rotation, Correspondingly, switching system is from the first gear change to the second gear for change with mode of operation.

Therefore, according to an aspect of the invention, there is provided a kind of electric tool, it at least has defeated Go out the first mode of operation of rotary motion and do not export the second mode of operation of rotary motion, it is described electronic Instrument includes：The drive part of rotary motion is provided；Support rotary cutter and export rotary motion Rotation output par, c；Running part, it is configured to the rotary motion of drive part passing to institute Stating rotation output par, c makes its export rotational motion；Clutch system, it has and first Working mould Engagement state corresponding to formula and disengaged condition corresponding with second mode of operation, and be configured to So that when the electric tool in the first mode of operation meets with the drag torque more than pre-determined torque from connecing Conjunction state is transformed into the second mode of operation to be converted to disengaged condition, by electric tool；Switching system, It has the first gear corresponding with first mode of operation and corresponding with second mode of operation Second gear；And the coupling part engaged with both clutch system and switching system, it is constructed Into triggering the switching system when clutch system is converted to disengaged condition from engagement state from the first gear Change to the second gear.

According to an alternative embodiment, the clutch system is arranged on running part, and is constructed Passed into cut-out when the drag torque more than pre-determined torque is met with the electric tool in the first mode of operation Connecing between the engagement or cut-out running part and rotation output par, c between dynamic part and drive part Close.

According to an alternative embodiment, the running part includes the jackshaft being axially movable, described Jackshaft passes through the first engaging mechanism and the second engaging mechanism and drive part and rotation output par, c respectively Engagement, and be configured to meet with more than pre-determined torque in the electric tool in the first mode of operation The engagement between drive part is departed from by axial movement during drag torque.

According to an alternative embodiment, first engaging mechanism and the second engaging mechanism are that tooth engages machine Structure, and one or both of first engaging mechanism and second engaging mechanism are configured to helical teeth engagement Mechanism, thus form the clutch system.

According to an alternative embodiment, the drive part includes motor output shaft and by motor output shaft The drive socket for driving and being rotated, on the internal tooth and the jackshaft set on the drive socket The little gear of setting forms first engaging mechanism.

According to an alternative embodiment, the output par, c that rotates includes support the rotation of electric tool Cutter and the hammer pipe for driving rotary cutter to rotate together, it is described hammer pipe on first gear with it is described in First gear engagement on countershaft forms second engaging mechanism.

According to an alternative embodiment, electric tool also includes the impact knot of output alternating translational movement Structure, the drive socket drive impact structure to carry out back and forth by the driving bearing being arranged on jackshaft Translational motion.

According to an alternative embodiment, the coupling part is connected to the jackshaft and described The action is passed into the switching system when jackshaft moves axially.

According to an alternative embodiment, the clutch system is arranged in the rotation output par, c, and And cut-out passes when the electric tool in the first mode of operation meets with the drag torque more than pre-determined torque Engagement between dynamic part and rotation output par, c.

According to an alternative embodiment, the output par, c that rotates includes support the rotation of electric tool Cutter and the hammer pipe for driving rotary cutter to rotate together, the hammer pipe and the running part wrap respectively Intermeshing first gear and second gear are included,

The clutch system and switching system include clutch discs and the mesh plate being arranged on hammer pipe respectively, The mesh plate is releasably coupled to an inner with the first gear, and clutch discs and mesh plate are configured to The clutch discs energy when the electric tool in the first mode of operation meets with the drag torque more than pre-determined torque Enough make axial movement of the mesh plate along the hammer pipe, so as to depart from the engagement with the first gear.

According to an alternative embodiment, the coupling part is connected to the clutch discs and mesh plate two Person, the clutch discs drive mesh plate to be moved together along the axial direction of the hammer pipe by the coupling part It is dynamic.

According to an alternative embodiment, electric tool also includes the impact knot of output alternating translational movement Structure, the running part also include the 3rd gear for driving the beater mechanism.

According to an alternative embodiment, the drive part includes driving the second gear and described the The motor driving shaft of both three gears.

According to an alternative embodiment, axial direction cloth of the motor driving shaft perpendicular to the hammer pipe Put or arranged parallel to the axial direction of the hammer pipe.

According to an alternative embodiment, the switching system includes the rotation supported by housing of electric tool Button.

According to an alternative embodiment, the knob is at least partially exposed to outside electric tool.

According to an alternative embodiment, first mode of operation includes the rotation output par, c output The hammer drill pattern and the rotation of rotary motion and impact structure output alternating translational movement are defeated Go out part output rotary motion but the impact structure does not export the drill mode of alternating translational movement, institute State the second mode of operation and include the rotation output par, c and do not export rotary motion but the impact structure is defeated The hammer mode and the rotation output par, c for going out alternating translational movement do not export rotary motion and institute State the standby mode that impact structure does not export alternating translational movement.

According to an alternative embodiment, the coupling part is constructed mechanically or electronically, Make its automatic so that triggering the switching system when clutch system is converted to disengaged condition from engagement state Changed from the first gear to the second gear on ground.

According to an alternative embodiment, the electric tool is hammer drill, or pricker is hammered into shape or impact drill.

Huge resistance is run into according to the cutter that the electric tool of the present invention is included in rotation process pattern Rotary motion can " for good and all " be cut off to the clutch system and switching system of the transmission of cutter, make during power Electric tool irreversibly changes to from the first gear of output rotary motion and does not export rotary motion automatically The second gear.Clutch system may be disposed at any appropriate location of electric tool, such as be arranged at On countershaft or hammer pipe is first-class.

Using the structure according to the present invention, destroy torque and be not transferred to the operator of electric tool, keep away Exempt to damage operator, securely and reliably；Meanwhile motor is cut off to rotation fortune between cutter After dynamic transmission, the transmission of rotary motion will not recover automatically, avoid the occurrence of and break as existing structure The operation repeatedly opening, engage, disconnecting again, rejoining, alleviates abrasion, it is thus possible to greatly prolong The life-span of transmission device.In addition, in order to achieve this, only the straight-tooth gear in transmission device is changed For helical gear, the improvement to structure is minimum, and cost is minimum.

Brief description of the drawings

The above and other advantage and feature of the application is by from the following preferred embodiment to being shown in accompanying drawing Detailed description in be better understood.

Fig. 1 is the sectional view of a part for electric tool according to the first embodiment of the invention；

Fig. 2 is the sectional view of a part for Fig. 1 electric tool, basically illustrates switching system and company Socket part point；

Fig. 3 is the stereogram of a part for Fig. 1 electric tool, basically illustrates switching system and company Socket part point；

Fig. 4 is the principle sketch of the first embodiment of the electric tool shown in Fig. 1-3；

Fig. 5 is the first embodiment of electric tool second embodiment of the invention；

Fig. 6 is the second embodiment of electric tool second embodiment of the invention；

Electric tool, with Fig. 4 corresponding principle letters of the Fig. 7 and 8 namely for Fig. 5 and 6 Figure.

Embodiment

It can be applied to build according to the electric tool of the present invention, decorate, in the relevant industries such as house ornamentation, using To drill, burrow in the stiff materials such as fragment of brick, cement concrete or slabstone, including but not only It is limited to hammer drill, pricker hammer, jump bit.

At least two mode of operations are had according to the electric tool of the present invention：The first of rotation can be exported Mode of operation and the second mode of operation that rotation can not be exported.First mode of operation and the second mode of operation The different mode of operation of one, two or more can be included respectively.

In structure, included that the rotation output section of rotation can be exported according to the electric tool of the present invention Point, such as the drilling cutters of hammer drill, cutter support frame and the hammer pipe for supporting cutter support frame；Can The drive part of rotation driving, such as the motor and motor output shaft of hammer drill are provided；Exported positioned at rotation Running part between part and drive part, such as the jackshaft of hammer drill and transmission gear etc..Drive Rotary motion is transferred to rotation output par, c via running part and rotated so as to export by dynamic part, such as The drilling campaign of hammer drill.

According to the present invention, in order that electric tool is cut automatically from the first mode of operation that can export rotation The second mode of operation of rotation can not be exported by changing to, and electric tool is provided with clutch system A, switching system The C and coupling part B between them.

According to the present invention, clutch system A, which has, departs from and engages two states, and clutch system engages then Electric tool is in the first mode of operation, and clutch system disengages then electric tool and is in the second Working mould Formula.Clutch system A may be disposed on running part, can engage and cut off rotation output par, c and biography Engagement between dynamic part and/or engagement between running part and drive part can be engaged and cut off, Such as it is arranged at as Figure 1-4 on jackshaft；Clutch system may be placed at rotation output par, c On, the engagement between rotation output par, c and running part can be engaged and cut off so as to drive part Rotary motion is no longer passed to rotation output par, c, such as is arranged at as viewed in figures 5-8 on hammer pipe； Or clutch system is also possible to be arranged on drive part, running part and drive can be engaged and cut off Engagement between dynamic part is so that its rotary motion is no longer passed to rotation output par, c.Alternatively, Clutch system can be arranged at any other position.

Correspondingly, switching system has at least following two gears：Corresponding to the joint shape of clutch system State and the first gear for therefore corresponding to the first mode of operation of electric tool, and corresponding to clutch system The disengaged condition of system and the second gear for therefore corresponding to the second mode of operation of electric tool.It is preferred that Ground, switching system can be supported on electric power tool shell.It is highly preferred that switching system can at least portion Point ground is outside the electric tool, so as to when needed can be manually operated by user.

Coupling part engages with both clutch system and switching system, can be by the engagement of clutch system/de- Open state is transferred to switching system automatically, so that switching system is automatically from the first gear change to Two gears.Coupling part can have any appropriate structure, for example can be bar, pin, driving lever Deng.

Below with reference to the accompanying drawings the principle of the present invention is described in detail by taking hammer drill as an example.In each accompanying drawing, function or The same or similar element of structure is represented with identical or corresponding reference marker.

Fig. 1 shows a part for hammer drill 100 in the form of partial sectional view.Structure is shown in Fig. 1 Into the main composition part of above-mentioned rotation output par, c：Hammer pipe 10 into shape, relative can not turn on hammer pipe 10 Fixed gear 12 dynamicly；Form the main composition part of above-mentioned drive part：The motor output of motor Axle 20, output shaft 20 is gear shaft in the example in figure；And form the master of above-mentioned running part Want component parts：Jackshaft 30 and drive socket 50.

Fixed gear 32 relatively unrotatablely on jackshaft 30, its engaged with gear 12 so that The driving hammer pipe 10 of jackshaft 30 rotates；Fixed gear relatively unrotatablely on drive socket 50 52, it is engaged with gear shaft 20 so that motor output shaft 20 drives drive socket 50 to rotate；Separately Outside, the fixed gear 34 relatively unrotatablely of jackshaft 30, it is configured to and drive socket 50 Internal tooth 54 engagement so as to drive socket 50 drive jackshaft 30 rotate.

During hammer drill, motor driving shaft 20 drives drive socket 50 to revolve by being engaged with gear 52 Turn, drive socket 50 drives jackshaft 30 to rotate by the engagement of internal tooth 54 and gear 34, middle The rotary motion of axle 30 is rotated by the engagement driving hammer pipe 10 of gear 32 and 12, so as to which hammer drill is defeated Go out drilling campaign.

As first embodiment according to the principles of the present invention, when hammer drill is met with the first mode of operation The clutch system that electric tool can be automatically switched to the second mode of operation during large drag forces is arranged at On running part, such as on the jackshaft 30 of diagram.

In Fig. 1, the tooth on gear 32 and 34 and their coupling gear 12 and 54 is oblique Tooth.When hammer drill meets with immense pressure in drilling process or destroys torque (as shown in Figure 1), by In the engagement of helical gear 12 and 32, jackshaft 30 is by axial force F 1；Due to gear 34 and transmission The helical teeth engagement of the internal tooth 54 of sleeve 50, jackshaft 30 is by axial force F 2.When F1's and F2 During with more than predetermined value, jackshaft 30 is moved to the left the internal tooth so as to gear 34 and drive socket 50 54 are disengaged from.So, motor output shaft 20 and drive socket 50 no longer drive 10 turns of pipe of hammer Dynamic, drilling campaign stops.

This two groups of helical teeth engagements constitute above-mentioned clutch system.It will be understood to one skilled in the art that Resistance overcome according to required for destroying the predetermined value of torque, enable jackshaft 30 to move axially etc. Factor, and the parameter such as helical angle by rationally designing helical teeth, it is any in above-mentioned two groups of helical teeth engagement Group helical teeth engagement may make up the clutch system of the present invention, be simultaneously oblique without the engagement of two groups of teeth wheel Tooth engages.

A part for switching system is also show in Fig. 1, and Fig. 2 and Fig. 3 respectively illustrate connecting portion Divide and the partial sectional view of switching system and partial perspective view.Switching system includes being usually supported at hammer Bore the knob 62 on shell；Compression spring 61, positioned at the spheroid 63 of both ends of the spring, " it " shape is driven Dynamic pin 64；The arc shell 66 that can be moved axially with jackshaft 30.Pin 68 is fixed in centre Moved left and right on axle 30 with together with jackshaft 30.When jackshaft 30 is moved to the left together with pin 68 When, the supporting leg 72 of U clamps drives the end 76 of " it " shape drive pin 64 to move, " it " shape The end 78 that drive pin 64 is fixed in knob 62 then forces knob 62 to rotate.Thus, The axial movement of jackshaft 30 can be transferred to knob 62 by drive pin 64, make knob 62 from first Gear P1 (Fig. 1) automatically changes to the second gear P2 (Fig. 1).

Knob 62 at least has first gear P1 corresponding with the engagement state of clutch system and and clutch Second gear P2 corresponding to the disengaged condition of system.Fig. 1 shows that knob 62 is in the first gear P1, I.e. electric tool is in the mode of operation of output drilling campaign, such as hammer drill pattern.

In addition, according to actual conditions, the helical teeth helical angle of gear mesh 12 and 32 and 34 and 54 can With equal, it can also be provided that.

Those skilled in the art understand that hammer drill also has the impact for being used for exporting alternating translational movement Output par, c.Referring back to Fig. 1, impact output par, c includes the beater mechanism being arranged in hammer pipe 10 (not shown).The driving bearing 42 being arranged on jackshaft 30 engages with drive socket 50, motor Motor output shaft 20 drive drive socket 50 to rotate so that driving bearing 42 is swung, and then Drive above-mentioned beater mechanism to move back and forth, realize the blasting operation of hammer drill.This is not of the invention Emphasis, I will not elaborate.

According to the principle of the present invention, the drilling cutters of hammer drill meet with large drag forces or destructive torque When, destructive torque makes jackshaft 30 bear the axial force of (as shown in Figure 1) to the left, when to the left Axial force F 1+F2 or F1 or F2 overcome the resistance of jackshaft 30 and be moved to the left jackshaft 30 When, jackshaft 30 is no longer by the driving of motor output shaft 20, so as to which engagement between the two is thoroughly cut It is disconnected.This aspect protects the injury of operator's not being damaged property torque, on the other hand will not be as existing The structure of technology damages to the internals of hammer drill like that.

Fig. 4 shows the sketch of Fig. 1-3 operation principle, and output rotation fortune is diagrammatically illustrated in figure Dynamic cutter 80, such as drill bit, hammer pipe 10, jackshaft 30, gear 12 and 32, motor driving into shape Axle 20, with the meshed gears 52 of motor driving shaft 20, impact structure 82, and oscillation bearing 42 Deng.Wherein, it is arranged on the jackshaft 30 of running part, is cut according to the clutch system A of the present invention Change system C, i.e. switching knob 62 to be supported on shell, (" it " shape drives coupling part B Pin 64) it is arranged between clutch system A and switching system C, for by clutch system A state Conversion is transferred to switching system C automatically, switching system C is automatically changed to second gear from the first gear Position.

As described previously, the present invention is not restricted to the structure arrangement in Fig. 1-4, and Fig. 5-7 is shown Second embodiment of the present invention.Second embodiment of the invention, clutch system A is arranged at On the hammer pipe 10 for rotating output par, c, it is configured to when hammering pipe 10 into shape and meeting with destructive torque in cut-out Driving of the countershaft 30 to hammer pipe 10.

Generally, as an example of second embodiment, clutch system A mainly includes clutch discs With the spring of pushing and pressing clutch discs, switching system C includes knob and mesh plate etc..Clutch discs and mesh plate All it is arranged on hammer pipe 10.Switching system C may include as Fig. 1 to 4 first embodiment The knob 62 of construction.Via coupling part B, clutch system A disengagement can make switching system C from First gear P1 as shown in Figure 1 is automatically transitioned to the second gear P2.

Coupling part B is configured to be engaged with both clutch discs and mesh plate, for example, can have as schemed Structure shown in 5 and 6, or any other structure that can realize identical function.Meet with hammer pipe 10 When meeting the destructive torque more than pre-determined torque, clutch discs make coupling part B be moved along hammer pipe, connect B driving mesh plates in part move together, so as to engage disk detachment with hammering nibbling for the gear 12 on pipe 10 into shape Close, the gear 12 for making to be rotated no longer drives hammer pipe 10 to rotate

Fig. 5 and Fig. 6 is respectively illustrated including clutch system A, the connecting portion according to second embodiment It is divided to the hammer drill 200 and 300 of B and switching system C two kinds of different structures.Fig. 7 and 8 is shown respectively The hammer drill for having gone out Fig. 5 and 6 corresponds to Fig. 4 principle sketch.

Hammer drill in Fig. 5 is represented with 200, shows that motor driving shaft 220 is managed perpendicular to hammer in figure 210.Motor driving shaft 220 is equally the form of gear shaft, and gear shaft drives first gear when rotating 252 and second gear 254 rotate, first gear 252 driving positioned at hammer pipe 210 on gear 212 So as to drive hammer pipe 210 to rotate, hammer drill 200 is set to export rotary motion (drilling), second gear 254 are used to drive the beater mechanism being placed in hammer pipe 210, for making hammer drill 200 export back and forth Translational motion (hammering).

Specifically, clutch part A is arranged on hammer pipe 210, including clutch discs 214 and pushing and pressing clutch The spring 218 of disk 214.In the case of normal drilling, gear 212 drives mesh plate 216 and hammer pipe 210 It is rotated.When hammer drill 200 meets with the destruction torque more than pre-determined torque, clutch discs 214 Effect against spring 218 is moved to the left along the axial direction for hammering pipe 210 into shape, while is driven as connection Part B connecting rod 264 and mesh plate 216 is moved to the left together.On the one hand, mesh plate 216 with Gear 212 disengages, and disconnects gear 212 and the driving effect hammered into shape between pipe 210, no longer driving hammer Pipe 210 rotates；On the other hand, being moved to the left for coupling part 264 makes switching system C, is specially The first gear that button 262 hammers the output rotary motion of pipe 210 into shape therefrom automatically changes to wherein hammer pipe 210 do not export the second gear of rotary motion.

Fig. 6 is the structure of another hammer drill 100 according to second embodiment of the invention, shows hammer drill 300 shell 301, hammer pipe 310 into shape, and be motor driven the jackshaft of axle (not shown) driving 330.Jackshaft 330 is engaged by gear 332 and gear 312, and driving hammer pipe 310 rotates.No The hammer drill structure being same as in Fig. 6, in the present embodiment, motor driving shaft parallel to hammer pipe 310 and Parallel to jackshaft 330.

In the present embodiment, clutch system A is also disposed on hammering into shape on pipe 310, has and is similar in Fig. 5 Clutch system structure.It is different from, is needed for structure, the connecting rod as coupling part B 364 is slightly different in structure.

According to the present invention, clutch system A can also have any other structure, be arranged at electric tool Any other position, as long as can realize purpose that as described above, cut-out hammer pipe is driven in rotation i.e. Can.Same switching system C and coupling part B can also have any appropriate structure, as long as can Realize the purpose of the present invention.Particularly, coupling part B can with it is as described above mechanically Be bonded between clutch system A and switching system C, alternatively, can also make clutch system A and Switching system C is electronically engaged, and realizes switching system C as clutch system A is from joint shape State is changed to disengaged condition and is transformed into the second gear from the first gear automatically, while ensures this conversion Irreversibility.

The preferred embodiments of the present invention are provided above with reference to accompanying drawing.Those skilled in the art should be understood that Described above is served only for explaining the principle of the present invention, and is intended to limit the scope of the present invention.Not inclined In the case of principle and essence from the present invention, those skilled in the art can be to showing in figure And feature described above, structure, form etc. carry out various modifications, addition or substituted, and institute There are these modifications, addition or substitute and be all within the scope of the present invention.

Claims

1. a kind of electric tool, it at least has the first mode of operation of output rotary motion and not exported Second mode of operation of rotary motion, the electric tool include：

The drive part of rotary motion is provided；

Support rotary cutter and export the rotation output par, c of rotary motion；

Running part, it is configured to the rotary motion of drive part passing to the rotation output section Dividing makes its export rotational motion；

Clutch system, it has engagement state corresponding with first mode of operation and with described second Disengaged condition corresponding to mode of operation, and be constructed such that in the electronic of the first mode of operation From engagement state to be converted to disengaged condition when instrument meets with the drag torque more than pre-determined torque, by electricity Power driven tools are transformed into the second mode of operation；

Switching system, it has the first gear corresponding with first mode of operation and with described second Second gear corresponding to mode of operation；And

The coupling part engaged with both clutch system and switching system, it is configured in clutch system System triggers the switching system when being converted to disengaged condition from engagement state and changed from the first gear to second Gear.

2. electric tool according to claim 1, wherein, the clutch system is arranged at transmission On part, and it is configured to meet with the electric tool in the first mode of operation and exceedes pre-determined torque Drag torque when cut off engagement between running part and drive part or cut-out running part with rotating Engagement between output par, c.

3. the electric tool stated according to claim 2, wherein, the running part includes axially moving Dynamic jackshaft (30), the jackshaft respectively by the first engaging mechanism and the second engaging mechanism with Drive part and rotation output par, c engagement, and be configured in the electronic of the first mode of operation Instrument is departed between drive part when meeting with the drag torque more than pre-determined torque by axial movement Engagement.

4. electric tool according to claim 3, wherein, first engaging mechanism and second Engaging mechanism is tooth engaging mechanism, and one of first engaging mechanism and second engaging mechanism or two Person is configured to helical teeth engaging mechanism, thus forms the clutch system.

5. electric tool according to claim 4, wherein, it is defeated that the drive part includes motor Shaft (20) and the drive socket (50) for being driven by motor output shaft (20) and being rotated, institute State the small tooth set on the internal tooth (54) and the jackshaft (30) set on drive socket (50) Take turns (34) and form first engaging mechanism.

6. the electric tool according to claim 4 or 5, wherein, the rotation output section subpackage The hammer pipe (10) for including the rotary cutter that support electric tool and driving rotary cutter to rotate together, First gear (12) on the hammer pipe (10) and the first gear on the jackshaft (30) (32) engagement forms second engaging mechanism.

7. electric tool according to claim 6, include the impact of output alternating translational movement Structure, the drive socket drive punching by the driving bearing (42) being arranged on jackshaft (30) Hit structure and carry out alternating translational movement.

8. according to the electric tool any one of claim 3-7, wherein, the coupling part It is connected to the jackshaft (30) and passes the action when the jackshaft moves axially Pass the switching system.

9. electric tool according to claim 1, wherein, the clutch system is arranged at described Rotate in output par, c, and met with the electric tool in the first mode of operation and exceed pre-determined torque Drag torque when cut off running part and rotate output par, c between engagement.

10. electric tool according to claim 9, wherein,

The output par, c that rotates includes support the rotary cutter of electric tool and drives rotary cutter The hammer pipe rotated together, the hammer pipe and the running part include intermeshing first gear respectively And second gear,

11. electric tool according to claim 10, wherein, the coupling part is connected to Both the clutch discs and mesh plate, the clutch discs drive mesh plate together by the coupling part Along the axial movement of the hammer pipe.

12. electric tool according to claim 11, in addition to export rushing for alternating translational movement Structure is hit, the running part also includes the 3rd gear for driving the beater mechanism.

13. electric tool according to claim 12, wherein, the drive part includes driving The motor driving shaft of both the second gear and the 3rd gear.

14. according to the electric tool any one of claim 9-13, wherein, the motor drives Moving axis is arranged perpendicular to the axial direction arrangement of the hammer pipe or parallel to the axial direction of the hammer pipe.

15. according to the electric tool any one of claim 1-14, wherein, the switching system System includes the knob supported by housing of electric tool.

16. electric tool according to claim 15, wherein, the knob is sudden and violent at least in part It is exposed at outside electric tool.

17. according to claim 3-7, the electric tool any one of 12-16, wherein, it is described First mode of operation includes the rotation output par, c output rotary motion and the impact structure exports The hammer drill pattern of alternating translational movement and the rotation output par, c output rotary motion but the impact Structure does not export the drill mode of alternating translational movement, and it is defeated that second mode of operation includes the rotation Go out part do not export rotary motion but the impact structure output alternating translational movement hammer mode and The rotation output par, c does not export rotary motion and the impact structure does not export alternating translational movement Standby mode.

18. electric tool according to claim 1, wherein, the coupling part is by with machinery Mode electronically constructs so that is triggered when clutch system is converted to disengaged condition from engagement state The switching system makes it automatically be changed from the first gear to the second gear.

19. according to the electric tool any one of claim 1-18, wherein, the electronic work Tool is hammer drill, or pricker is hammered into shape or impact drill.