CN114192840B

CN114192840B - Handheld electric percussion drill with protection braking function

Info

Publication number: CN114192840B
Application number: CN202210149914.9A
Authority: CN
Inventors: 朱杨华; 陶柏柏
Original assignee: Haimen Baijie Electric Tools Co ltd
Current assignee: Nantong Century Dynamoelectric Tools Co ltd
Priority date: 2022-02-18
Filing date: 2022-02-18
Publication date: 2022-05-06
Anticipated expiration: 2042-02-18
Also published as: CN114192840A

Abstract

The invention relates to the field of electric percussion drills, and discloses a hand-held electric percussion drill with protective braking, which can effectively reduce the vibration influence of a percussion drill shell when the percussion drill operates through the arrangement of a rubber pad, a compression spring and the like, realize stable drilling, improve the drilling efficiency of the electric percussion drill, change the initial position of a supporting push block through screwing a propelling screw rod into different lengths in a fixed cylinder, thereby realizing the adjustment of the initial position of the rubber pad so as to adapt to drill bits with different lengths for matching use, further improve the practicability of the percussion drill, enable a plurality of adaptive lugs to drive one ends of corresponding T-shaped slide blocks to be close to each other through the operation of a braking motor, further enable a plurality of rubber clamping blocks to clamp and brake the drill bits on the central position, thereby realizing emergency braking and avoiding the drill bits from causing injury to human bodies due to the rotation of inertia and the like, thereby greatly improving the safety of the electric percussion drill.

Description

Handheld electric percussion drill with protection braking function

Technical Field

The invention relates to the field of electric percussion drills, in particular to a handheld electric percussion drill with protection braking.

Background

An electric impact drill is an impact mechanism which mainly uses rotary cutting and depends on the thrust of an operator to produce impact force, is commonly used as an electric tool for drilling holes in materials such as bricks, building blocks, light walls and the like, and is required to be used in the fields of building construction and decoration in modern life.

However, the current popular electric percussion drill often has many disadvantages in use, such as unstable operation and loud operation sound, which easily causes sound pollution and affects the normal rest of residents, and also generates large dust pollution, which easily causes physical injury after being inhaled by human body, although the chinese patent document with publication number CN208304960U in the prior art proposes a dust-proof noise-reduction percussion drill for decoration to solve the problems of noise and dust pollution, the device does not solve the problems of unstable manual handling and easy occurrence of drilling deviation, etc. when the percussion drill is used, and at the same time, once fingers of an operator touch a drill bit rotating at high speed, the hand-held electric percussion drill with protection brake can also face great injury, so that the hand-held electric percussion drill with protection brake is disclosed to meet the use requirement of the electric percussion drill.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides the handheld electric percussion drill with the protection braking function, which has the advantages of intelligent braking and the like, and solves a series of problems that the percussion drill causes accidental injury to a human body in the prior art.

(II) technical scheme

In order to achieve the purpose, the invention provides the following technical scheme: a handheld electric percussion drill with protection braking comprises a percussion drill shell, wherein a driving mechanism and a drill bit which are connected are arranged on the percussion drill shell, a control switch which is electrically connected with the driving mechanism is further installed in the percussion drill shell, a closed circuit which can be matched with a human body to form a loop is further arranged on the percussion drill shell, and the closed circuit comprises a first electrode plate and an adaptive electrode plate which are matched with each other;

the percussion drill comprises a percussion drill shell, a drill bit and a buffer component, wherein the percussion drill shell is provided with the buffer component for improving the stability of the drill bit during operation, and the buffer component comprises a rubber pad which is in contact with a construction surface;

still be equipped with on the percussion drill casing with the brake subassembly of drill bit looks adaptation, brake subassembly is used for right the drill bit in time brakes, just brake subassembly contains a plurality of corresponding rubber clamp splice.

Preferably, the closed circuit further comprises a drill bit electrically connected with the adaptive electrode plate, the percussion drill casing is provided with a control switch for controlling the operation of the driving mechanism, one side of the control switch is fixedly connected with the first electrode plate, an operator operates the percussion drill casing and triggers the driving mechanism through the control switch and contacts with the first electrode plate, one end of the percussion drill casing is fixedly provided with the adaptive electrode plate which contacts with the drill bit, and the operator can contact with the drill bit and form the closed circuit through the adaptive electrode plate and the first electrode plate.

Preferably, the closed circuit further comprises a controller installed in the percussion drill casing and electrically connected to the first electrode plate and the adaptive electrode plate, the controller is electrically connected to the control switch and the brake assembly, and the current of the closed circuit is less than 10 mA.

Preferably, the buffer assembly further comprises a horizontal guide rod capable of driving the rubber pad to horizontally move, two fixed cylinders corresponding to the two positions are fixedly connected to the outer wall of the percussion drill casing, two first through holes are formed in one ends of the fixed cylinders, two corresponding horizontal guide rods are sleeved in the first through holes in a sliding mode and are corresponding to the first through holes respectively, the two horizontal guide rods correspond to the first through holes respectively and extend to the inner side and the outer side of the fixed cylinders respectively, two connecting discs are fixedly connected to the other ends of the horizontal guide rods, one side of each connecting disc is fixedly connected with the rubber pad which is in contact with the construction surface, and the rubber pad is coaxial with the drill bit.

Preferably, the buffering subassembly is still including changing the compression spring of the extrusion intensity of rubber pad, two horizontal guide arm extends to corresponding the equal fixedly connected with of one end in the fixed cylinder with correspond the support ejector pad that the inner wall of fixed cylinder all slided and cup jointed, and two still the interactive corresponding movable block that has cup jointed in two positions in the fixed cylinder, with one side support the ejector pad with it is same to go back fixedly connected with between the movable block compression spring.

Preferably, the one end of buffering subassembly still is connected with and is used for changing the adjusting part of movable block position, adjusting part contains two corresponding propulsion screw rods in position, two the other end of solid fixed cylinder all sets up threaded hole, and two the looks adaptation has been cup jointed to the downthehole equal screw thread of screw thread propulsion screw rod, and two it extends to corresponding to impel the screw rod one end in the solid fixed cylinder pass through the bearing and correspond the movable block rotates to be connected, two it extends to corresponding to impel the screw rod the equal fixedly connected with of the outside one end of solid fixed cylinder makes things convenient for pivoted rotatory cap.

Preferably, the brake subassembly is still including connecting a plurality ofly the T shape slider of rubber clamp splice, fixed the cup jointing has the retainer plate on the inner wall of connection pad, the retainer plate is close to one side of strikeing the brill casing is seted up a plurality of even T shape spouts of distribution, and is a plurality of equal sliding sleeve has cup jointed the looks adaptation in the T shape spout T shape slider, a plurality of the equal fixedly connected with of one end that T shape slider is close to each other with the drill bit position is corresponding the rubber clamp splice, the rubber clamp splice is the softwood matter and can be right the drill bit presss from both sides tightly.

Preferably, the brake assembly further comprises a driving assembly for driving the plurality of T-shaped sliders to be close to or far away from each other, the driving assembly comprises a spiral groove and an adaptation bump which are adapted to each other, one side of the fixing ring is further provided with a plurality of annular holes which are communicated with the T-shaped sliding grooves, a rotating cylinder which is adapted to each other is sleeved in the annular holes in a rotating mode, one end of the rotating cylinder extends into the annular holes and is provided with the spiral groove, and the bottom ends of the plurality of T-shaped sliders are fixedly connected with the adaptation bump which is sleeved in the spiral groove in a sliding mode.

Preferably, the drive assembly is still including driving rotatory section of thick bamboo pivoted brake motor, the one end of rotatory section of thick bamboo is located strike and bore the casing and fixed cover and have connect the drive ring gear, just fixedly connected with collar on the inner wall of retainer plate, fixed cover is connected in the collar has brake motor, just the one end of brake motor's output shaft extends to outside one side of brake motor and fixedly connected with drive ring gear engaged with brake gear.

(III) advantageous effects

Compared with the prior art, the invention provides a handheld electric percussion drill with protection braking, which has the following beneficial effects:

1. this handheld electronic impact drill with protection braking, the drilling in-process, through handheld impact drill casing's one end and to the construction face direction pressure of exerting, make then the rubber pad and the construction face keep in close contact with, follow the continuation of drill bit deep, the compression spring of both sides takes place elastic compression and holds power, can effectively alleviate the vibrations influence of impact drill casing when the impact drill operation then, realizes stable drilling, has improved the drilling efficiency that electronic impact drilled.

2. This handheld electric percussion drill with protection braking, the in-process that slows down vibrations through the compression spring of rubber pad and both sides, can also be according to the initial position of the different adjusting rubber pads of length of the drill bit that uses, through the rotatory cap that rotates both sides, make the propulsion screw rod spiral shell to different length in the solid fixed cylinder, then through the connection effect of bearing, promote the movable block and be located different positions in the solid fixed cylinder, change the initial position that supports the ejector pad then, thereby it is adjustable to realize the initial position of rubber pad, use in order to adapt to the drill bit of different length to cooperate, the practicality of percussion drill has further been improved.

3. This handheld electronic percussion drill with protection braking, in case the phenomenon that operating personnel touched the drill bit by mistake appears in the drilling process, then the adaptation electrode slice on the drill bit forms closed circuit through human body and first electrode slice and the controller in the percussion drill casing, the action of touching by mistake appears in the judgement promptly of controller, at this moment, close and control the brake motor operation through controller control switch, make the one end of the T shape slider that a plurality of adaptation lug drives correspond be close to each other, then make a plurality of rubber clamp splice press from both sides the tight braking of drill bit on with central point puts, thereby realize emergency braking, avoid the drill bit to keep rotating and cause the injury to the human body because of reasons such as inertia, thereby the security of electronic percussion drill has been improved greatly.

Drawings

FIG. 1 is a perspective view of a first embodiment of the present invention;

FIG. 2 is a perspective view of a second embodiment of the present invention;

FIG. 3 is a schematic top partially cut-away perspective view of the present invention;

FIG. 4 is a partially cut-away, partially exploded, alternate perspective, pictorial illustration of the present invention;

FIG. 5 is a perspective view of the brake assembly of the present invention;

FIG. 6 is a schematic perspective view of another embodiment of the brake assembly of the present invention;

FIG. 7 is a schematic view of a cutaway perspective structure of the connecting disc of the present invention;

FIG. 8 is a schematic view of another perspective view of the connecting disc of the present invention;

FIG. 9 is a schematic perspective view of a brake assembly according to the present invention;

FIG. 10 is a perspective view of the brake assembly of the present invention shown partially disassembled from another perspective view.

In the figure: 1. a percussion drill housing; 2. a drill bit; 3. a control switch; 4. a first electrode sheet; 5. adapting the electrode plate; 6. a fixed cylinder; 7. supporting the push block; 8. a horizontal guide rod; 9. a connecting disc; 10. a rubber pad; 11. a movable block; 12. a compression spring; 13. a bearing; 14. a screw is advanced; 15. rotating the cap; 16. a fixed ring; 17. a T-shaped chute; 18. a T-shaped slider; 19. a rubber clamping block; 20. an annular aperture; 21. a rotary drum; 22. a helical groove; 23. fitting the bump; 24. a drive gear ring; 25. braking the motor; 26. and a gear is braked.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As described in the background of the invention, there are shortcomings in the prior art, and in order to solve the above technical problems, the present application provides a hand-held electric impact drill with a protective brake.

In a typical embodiment of the present application, as shown in fig. 1 to 10, a handheld electric percussion drill with a protective brake includes a percussion drill casing 1, a driving mechanism and a drill bit 2 connected to each other are disposed on the percussion drill casing 1, a control switch 3 electrically connected to the driving mechanism is further mounted in the percussion drill casing 1, a closed circuit capable of forming a loop in cooperation with a human body is further disposed on the percussion drill casing 1, and the closed circuit includes a first electrode plate 4 and an adaptive electrode plate 5 which are adapted to each other;

the percussion drill shell 1 is also provided with a buffer assembly for improving the stability of the drill bit 2 during operation, and the buffer assembly comprises a rubber pad 10 which is in contact with a construction surface;

the percussion drill shell 1 is further provided with a brake assembly matched with the drill bit 2, the brake assembly is used for braking the drill bit 2 in time, and the brake assembly comprises a plurality of corresponding rubber clamping blocks 19.

Further, in the above scheme, closed circuit still includes drill bit 2 with 5 electric connection of adaptation electrode slice, be equipped with on the percussion drill casing 1 and be used for controlling actuating mechanism moving control switch 3, and the first electrode slice 4 of one side fixedly connected with of control switch 3, operating personnel triggers actuating mechanism and contacts with first electrode slice 4 through control switch 3 when operating percussion drill casing 1, and the one end of percussion drill casing 1 still fixed mounting have the adaptation electrode slice 5 that contacts with drill bit 2, can realize forming closed circuit through adaptation electrode slice 5 and first electrode slice 4 when operating personnel contacts with drill bit 2, through setting up closed circuit, in time trigger braking subassembly carries out emergency braking to drill bit 2.

As an implementation manner in this embodiment, the closed circuit further includes a controller installed in the percussion drill casing 1 and electrically connected to the first electrode plate 4 and the adaptive electrode plate 5, the controller is electrically connected to the control switch 3 and the brake assembly, and the current of the closed circuit should be less than 10mA, and a safety current parameter smaller than that of a human body is set, so as to avoid the closed circuit from causing damage to the human body.

Further, in above-mentioned scheme, the buffer unit is still including the horizontal guide 8 that can drive rubber pad 10 and realize horizontal migration, strike and bore two fixed barrels 6 that the position is corresponding on the outer wall of casing 1, and first perforation has all been seted up to the one end of two fixed barrels 6, the horizontal guide 8 of looks adaptation has all been cup jointed in two first perforations to the equal slip, and the one end of two horizontal guide 8 runs through corresponding first perforation respectively and extends to the inside and outside of the fixed barrel 6 that corresponds respectively, the equal fixedly connected with connection pad 9 of the other end of two horizontal guide 8, and the rubber pad 10 that one side fixedly connected with of connection pad 9 and construction face contacted, and rubber pad 10 is coaxial with drill bit 2, through setting up rubber pad 10, make things convenient for operating personnel to apply external force, extrude rubber pad 10, reduce the vibrations influence of striking and bore casing 1.

As an implementation in this embodiment, the buffer assembly is still including the compression spring 12 who changes the extrusion intensity of rubber pad 10, the equal fixedly connected with of one end in two horizontal guide rods 8 extend to the solid fixed cylinder 6 that corresponds supports ejector pad 7 that the inner wall of the solid fixed cylinder 6 that corresponds all slided and cup jointed, and two solid fixed cylinders 6 are interior still interactive to be cup jointed two corresponding movable blocks 11 in position, the same compression spring 12 of fixedly connected with still between support ejector pad 7 and the movable block 11 with one side, through setting up compression spring 12, realize following drilling depth extrusion rubber pad 10 of drill bit 2.

Further, in above-mentioned scheme, the one end of buffering subassembly still is connected with the adjusting part that is used for changing the movable block 11 position, the adjusting part contains two corresponding propulsion screw rods 14 in position, the other end of two solid fixed cylinders 6 all sets up threaded hole, and the propulsion screw rod 14 of looks adaptation has been cup jointed to two downthehole equal screw threads of screw thread, and two propulsion screw rods 14 extend to the one end in the solid fixed cylinder 6 that corresponds and pass through bearing 13 and be connected with 11 rotations of movable block that correspond, two propulsion screw rods 14 extend to the outside equal fixedly connected with of one end of solid fixed cylinder 6 that corresponds make things convenient for pivoted swivel cap 15, through setting up adjusting part, make things convenient for rubber pad 10 to cooperate 2 uses of drill bit that multiple length differs.

As an implementation manner in this embodiment, the brake assembly further includes a T-shaped slider 18 connected to a plurality of rubber clamping blocks 19, a fixing ring 16 is fixedly connected to the inner wall of the connecting disc 9, a plurality of T-shaped sliding grooves 17 distributed uniformly are formed in one side of the fixing ring 16 close to the percussion drill casing 1, the T-shaped sliders 18 matched with each other are slidably sleeved in the plurality of T-shaped sliding grooves 17, the rubber clamping blocks 19 corresponding to the positions of the drill bits 2 are fixedly connected to one ends of the plurality of T-shaped sliders 18 close to each other, the rubber clamping blocks 19 are made of soft materials and can clamp the drill bits 2, and by arranging the plurality of rubber clamping blocks 19, the drill bits 2 are clamped flexibly, so that the hard clamping is avoided from reducing the braking effect or damaging the drill bits 2.

Further, in above-mentioned scheme, the brake assembly still includes the drive assembly who is used for driving a plurality of T shape sliders 18 and is close to or keeps away from each other, drive assembly contains the helicla flute 22 and the adaptation lug 23 of looks adaptation, the annular opening 20 with a plurality of T shape spout 17 homogeneous phase intercommunication is still seted up to one side of retainer plate 16, the rotatory section of thick bamboo 21 of looks adaptation has been cup jointed in the annular opening 20 internal rotation, and the one end of rotatory section of thick bamboo 21 extends to in the annular opening 20 and has seted up helicla flute 22, the equal fixedly connected with in bottom of a plurality of T shape sliders 18 slides and cup joints the adaptation lug 23 in helicla flute 22, through setting up drive assembly, make rotatory section of thick bamboo 21 rotate and drive a plurality of adaptation lugs 23 and rotate, one end with a plurality of T shape sliders 18 of drive is close to each other or keeps away from, realize quick braking.

As an implementation manner in this embodiment, the driving assembly further includes a brake motor 25 capable of driving the rotary drum 21 to rotate, one end of the rotary drum 21 is located in the percussion drill casing 1 and is fixedly sleeved with a driving gear ring 24, and a mounting ring is fixedly connected to the inner wall of the fixing ring 16, the brake motor 25 is fixedly sleeved in the mounting ring, one end of an output shaft of the brake motor 25 extends to one side of the brake motor 25 and is fixedly connected with a brake gear 26 engaged with the driving gear ring 24, the brake gear 26 is driven to rotate by the operation of the brake motor 25, and then the driving gear ring 24 is driven to rotate, so that the rotary drum 21 rotates to drive the plurality of rubber clamping blocks 19 to emergently brake the drill bit 2.

The working principle of the invention is as follows: when using electronic percussion drill, at first hug closely rubber pad 10 on the construction face, and start the percussion drill through pressing control switch 3, then make 2 high-speed rotatory realization drilling of drill bit, simultaneously at the drilling in-process, the one end of boring casing 1 and to the construction face direction application pressure through handheld percussion, then make rubber pad 10 and construction face keep in close contact with, follow the continuation of drill bit 2 and go deep, the compression spring 12 of both sides takes place elastic compression and holds power, then can effectively alleviate the vibrations influence of percussion drill casing 1 when the percussion drill operates, realize stable drilling, the drilling efficiency of electronic percussion drill has been improved.

Above-mentioned impact drill when operation, the in-process that slows down vibrations through the compression spring 12 of rubber pad 10 and both sides, can also be according to the different initial position of adjusting the rubber pad 10 of the length of the drill bit 2 that uses, through the rotatory cap 15 that rotates both sides, make advance 14 spiro union of screw rod to different length in the solid fixed cylinder 6, then the connection effect through bearing 13, promote the movable block 11 and be located different positions in the solid fixed cylinder 6, then the initial position that changes support ejector pad 7, thereby it is adjustable to realize the initial position of rubber pad 10, use in order to adapt to the drill bit 2 of different length to cooperate, the practicality of impact drill has further been improved.

When the electric percussion drill is used, the palm of an operator is in contact with the first electrode plate 4, if the phenomenon that the operator mistakenly touches the drill bit 2 occurs during the drilling process, the adaptive electrode plate 5 on the drill bit 2 forms a closed circuit with the first electrode plate 4 and the controller in the percussion drill shell 1 through a human body, the controller judges that a false touch action occurs, at the moment, the controller controls the control switch 3 to be switched off and controls the brake motor 25 to operate, so that the brake gear 26 drives the driving gear ring 24 to rotate, and then the rotary drum 21 rotates, and drives one end of the corresponding T-shaped sliding block 18 to approach each other through a plurality of adaptive lugs 23, so that a plurality of rubber clamping blocks 19 clamp and brake the drill bit 2 at the central position, therefore, emergency braking is realized, the damage to the human body caused by the fact that the drill bit 2 keeps rotating due to reasons such as inertia and the like is avoided, and the safety of the electric percussion drill is greatly improved.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The utility model provides a handheld electronic percussion drill with protection braking, bores casing (1) including the impact, be equipped with actuating mechanism and drill bit (2) that are connected on the percussion drill casing (1), just still install in the percussion drill casing (1) with actuating mechanism electric connection's control switch (3), its characterized in that:

the percussion drill comprises a percussion drill shell (1), a drill bit (2) and a buffer assembly, wherein the percussion drill shell (1) is also provided with the buffer assembly for improving the stability of the drill bit (2) during operation, and the buffer assembly comprises a rubber pad (10) which is in contact with a construction surface;

the percussion drill comprises a percussion drill shell (1), a drill bit (2) and a brake assembly, wherein the percussion drill shell (1) is also provided with the brake assembly matched with the drill bit (2), the brake assembly is used for timely braking the drill bit (2), and the brake assembly comprises a plurality of corresponding rubber clamping blocks (19);

the buffer assembly further comprises a horizontal guide rod (8) capable of driving the rubber pad (10) to horizontally move, two fixed cylinders (6) corresponding to each other in position are fixedly connected to the outer wall of the impact drill casing (1), first through holes are formed in one ends of the two fixed cylinders (6), the two first through holes are sleeved with the horizontal guide rod (8) in a sliding mode, one ends of the two horizontal guide rods (8) penetrate through the corresponding first through holes respectively and extend to the inner side and the outer side of the corresponding fixed cylinders (6) respectively, connecting discs (9) are fixedly connected to the other ends of the two horizontal guide rods (8), the rubber pad (10) in contact with a construction surface is fixedly connected to one side of each connecting disc (9), and the rubber pad (10) is coaxial with the drill bit (2); the brake assembly further comprises a T-shaped sliding block (18) connected with a plurality of rubber clamping blocks (19), a fixing ring (16) is fixedly sleeved on the inner wall of the connecting disc (9), one side, close to the percussion drill shell (1), of the fixing ring (16) is provided with a plurality of T-shaped sliding grooves (17) which are uniformly distributed, the T-shaped sliding blocks (18) which are matched with each other are sleeved in the T-shaped sliding grooves (17) in a sliding mode, one ends, close to each other, of the T-shaped sliding blocks (18) are fixedly connected with the rubber clamping blocks (19) corresponding to the positions of the drill bits (2), and the rubber clamping blocks (19) are soft and can clamp the drill bits (2);

the brake assembly further comprises a driving assembly used for driving the T-shaped sliding blocks (18) to be close to or far away from each other, the driving assembly comprises a spiral groove (22) and an adaptive lug (23) which are matched with each other, one side of the fixing ring (16) is further provided with an annular hole (20) which is communicated with the T-shaped sliding grooves (17), the annular hole (20) is rotatably sleeved with a matched rotary cylinder (21), one end of the rotary cylinder (21) extends into the annular hole (20) and is provided with the spiral groove (22), and the bottom ends of the T-shaped sliding blocks (18) are fixedly connected with the adaptive lug (23) which is sleeved in the spiral groove (22) in a sliding manner;

still be equipped with the closed circuit that can cooperate the human body to form the return circuit on percussion drill casing (1), closed circuit contains first electrode slice (4) and adaptation electrode slice (5) of looks adaptation, through setting up closed circuit, in time triggers braking component and carries out emergency braking to drill bit (2).

2. A hand-held power hammer drill with safety brake as claimed in claim 1, wherein: closed circuit still include with adaptation electrode slice (5) electric connection drill bit (2), be equipped with on the impact drill casing (1) and be used for control actuating mechanism moving control switch (3), just one side fixedly connected with of control switch (3) first electrode slice (4), operating personnel operate pass through during the impact drill casing (1) control switch (3) trigger actuating mechanism and with first electrode slice (4) contact, just the one end of impact drill casing (1) still fixed mounting have with drill bit (2) contact adaptation electrode slice (5), operating personnel with can pass through during drill bit (2) contact adaptation electrode slice (5) and first electrode slice (4) are realized forming closed circuit.

3. A hand-held power hammer drill with safety brake as claimed in claim 2, wherein: the closed circuit further comprises a controller which is installed in the percussion drill shell (1) and electrically connected with the first electrode plate (4) and the adaptive electrode plate (5), the controller is electrically connected with the control switch (3) and the brake assembly, and the current of the closed circuit is smaller than 10 mA.

4. A hand-held power hammer drill with safety brake as claimed in claim 3, wherein: buffering subassembly is still including changing compression spring (12), two of the extrusion intensity of rubber pad (10) horizontal guide arm (8) extend to corresponding the equal fixedly connected with of one end in solid fixed cylinder (6) with correspond the support ejector pad (7) that the inner wall of solid fixed cylinder (6) all slided and cup jointed, and two still the interaction has cup jointed two corresponding movable blocks (11) in solid fixed cylinder (6), with one side support ejector pad (7) with it is same to go back fixedly connected with between movable block (11) compression spring (12).

5. The hand-held electric percussion drill with a protective brake according to claim 4, wherein: the one end of buffering subassembly still is connected with and is used for changing the adjusting part of movable block (11) position, adjusting part contains two corresponding propulsion screw rod (14) in position, two the other end of solid fixed cylinder (6) is threaded hole all, and two equal screw-thread joint in threaded hole has the looks adaptation propulsion screw rod (14), and two propulsion screw rod (14) extend to correspond one end in solid fixed cylinder (6) is passed through bearing (13) and is corresponded the movable block (11) rotates to be connected, two propulsion screw rod (14) extend to correspond the convenient pivoted of the equal fixedly connected with in one end of solid fixed cylinder (6) outside is rotatory cap (15).

6. A hand-held electric percussion drill with a protective brake according to claim 5, characterised in that: drive assembly is still including driving rotatory section of thick bamboo (21) pivoted brake gear (25), the one end of rotatory section of thick bamboo (21) is located strike and bore casing (1) in and fixed the drive ring gear (24) of having cup jointed, just fixedly connected with collar on the inner wall of collar (16), the fixed cup joint in the collar has brake gear (25), just the one end of the output shaft of brake gear (25) extends to one side of brake gear (25) outer and fixedly connected with drive ring gear (24) engaged with brake gear (26).