阅读说明：本技术 电锤的过载离合装置及电锤 (Overload clutch device of electric hammer and electric hammer ) 是由 张春官 吴丽莎 于 2021-09-07 设计创作，主要内容包括：本发明公开了一种电锤的过载离合装置及电锤,该过载离合装置包括：前离合板,前离合板具有多个齿槽,多个齿槽环设于前离合板的一端面；后离合板,后离合板具有多个轮齿,轮齿环设于后离合板的一端面,轮齿与齿槽一一对应设置,轮齿啮合于齿槽并能够沿前离合板的周向方向滑入或滑出齿槽,其中,轮齿沿周向方向的齿顶宽度不大于齿槽沿周向方向的长度的1/2；弹性元件,弹性元件用于施加一将前离合板压紧于后离合板的作用力。该过载离合装置过载时,轮齿滑出齿槽后并不会立即与下一个齿槽的内壁抵接,而需要滑动至少2倍齿顶宽度的距离后才能够与齿槽的内壁抵接,使得轮齿与齿槽接触的频率降低至少1/2,相应地降低过载离合装置产生的振动。(The invention discloses an overload clutch device of an electric hammer and the electric hammer, wherein the overload clutch device comprises: the front clutch plate is provided with a plurality of tooth grooves which are annularly arranged on one end surface of the front clutch plate; the rear clutch plate is provided with a plurality of gear teeth, the gear teeth are annularly arranged on one end face of the rear clutch plate, the gear teeth and the tooth grooves are arranged in a one-to-one correspondence mode, the gear teeth are meshed with the tooth grooves and can slide into or slide out of the tooth grooves along the circumferential direction of the front clutch plate, and the tooth top width of the gear teeth along the circumferential direction is not more than 1/2 of the length of the tooth grooves along the circumferential direction; and the elastic element is used for applying an acting force for pressing the front clutch plate to the rear clutch plate. When the overload clutch device is overloaded, the gear teeth cannot be immediately abutted against the inner wall of the next tooth groove after sliding out of the tooth groove, and the gear teeth can be abutted against the inner wall of the tooth groove after sliding for at least 2 times of the distance of tooth crest width, so that the frequency of the contact of the gear teeth and the tooth groove is reduced by at least 1/2, and the vibration generated by the overload clutch device is correspondingly reduced.)

1. An overload clutch device of an electric hammer is characterized by comprising:

the front clutch plate is provided with a plurality of tooth grooves, and the tooth grooves are annularly arranged on one end surface of the front clutch plate;

the rear clutch plate is provided with a plurality of gear teeth, the gear teeth are annularly arranged on one end face of the rear clutch plate, the gear teeth and the tooth grooves are arranged in a one-to-one correspondence mode, the gear teeth are meshed with the tooth grooves and can slide into or slide out of the tooth grooves along the circumferential direction of the front clutch plate, and the tooth top width of the gear teeth along the circumferential direction is not more than 1/2 of the length of the tooth grooves along the circumferential direction;

the elastic element is used for applying acting force for pressing the front clutch plate to the rear clutch plate;

when the counterforce generated by the relative rotation of the front clutch plate and the rear clutch plate is not larger than the acting force exerted on the front clutch plate by the elastic element, the rear clutch plate can drive the front clutch plate to synchronously rotate;

when the reaction force generated by the relative rotation of the front clutch plate and the rear clutch plate is greater than the acting force exerted on the front clutch plate by the elastic element, the gear teeth slide out of the previous tooth socket and slide into the next tooth socket, so that the front clutch plate slides in the direction away from the rear clutch plate.

2. The overload clutch apparatus for an electric hammer according to claim 1, wherein the tooth groove has a driving slope at a front end thereof, the driving slope abutting against a tooth surface of the tooth, an inclination angle of the driving slope with respect to the bottom surface of the tooth groove being determined in accordance with an output load of the overload clutch apparatus and a force applied to the front clutch plate by the elastic member.

3. The overload clutch apparatus for an electric hammer according to claim 2, wherein the tooth socket further has a transition slope at a rear end of the tooth socket for guiding the tooth to slide into the tooth socket from an outside of the tooth socket, an inclination angle of the transition slope with respect to the bottom surface of the tooth socket being smaller than an inclination angle of the driving slope with respect to the bottom surface of the tooth socket.

4. The overload clutch apparatus for an electric hammer according to claim 1, wherein the front clutch plate has a transition plane, the transition plane is disposed between adjacent ones of the tooth grooves, the tooth slides out from a previous one of the tooth grooves into a next one of the tooth grooves through the transition plane, and a length of the transition plane is not less than a crest width of the tooth.

5. The overload clutch apparatus for an electric hammer according to claim 4, wherein the rear clutch plate has a through hole through which a cylinder of the electric hammer is inserted, the rear clutch plate is rotatable with respect to the cylinder, an outer side of the through hole has an annular flange, the gear teeth are located on an outer side of the annular flange, and a height of the gear teeth is lower than a height of the annular flange, and an outer side of the annular flange abuts against an inner side of a transition plane of the front clutch plate.

6. The overload clutch device for an electric hammer according to any one of claims 1 to 5, wherein the front clutch plate has a receiving hole in a middle portion thereof, an inner wall of the receiving hole has a protruding driving portion, a sliding groove is provided on an outer circumferential surface of a cylinder of the electric hammer, the sliding groove extends in an axial direction of the cylinder, the cylinder is inserted into the receiving hole, the driving portion is inserted into the sliding groove and can slide along the sliding groove, and the front clutch plate is inserted into the sliding groove through the driving portion to drive the cylinder to rotate.

7. An electric hammer, characterized in that the electric hammer comprises a motor, an impact transmission mechanism, a rotation transmission mechanism, a cylinder assembly and the overload clutch device of the electric hammer according to any one of claims 1 to 6, wherein the motor drives the cylinder assembly to rotate through the rotation transmission mechanism and the overload clutch device, and the motor also impacts a drill bit of the cylinder assembly in a reciprocating manner through the impact transmission mechanism.

8. The electric hammer according to claim 7, wherein the cylinder assembly includes a cylinder, the rotation transmission mechanism includes a large gear, a bevel gear shaft, a large bevel gear and a connecting sleeve, the large bevel gear and the connecting sleeve are both sleeved on the cylinder and can rotate relative to the cylinder, the large gear is mounted at one end of the bevel gear shaft and is engaged with a rotor gear of the motor, the other end of the bevel gear shaft is engaged with the large bevel gear, and two ends of the connecting sleeve are respectively connected to the large bevel gear and the rear clutch plate.

9. The hammer of claim 8, wherein the rotation transmission mechanism further includes an elastic member that applies a force to press the connecting sleeve against the large cog.

10. The electric hammer according to claim 8, wherein the impact transmission mechanism includes a pinion gear, an eccentric shaft having one end mounted with the pinion gear in tooth engagement with a rotor of the motor, an eccentric shaft having the other end mounted with the eccentric gear, a connecting rod having both ends connected to the eccentric gear and the piston, respectively, and a piston located in the cylinder and capable of reciprocating sliding along the cylinder;

the eccentric shaft and the bevel gear shaft are arranged in parallel and are positioned on two sides of rotor teeth of the motor.

Technical Field

The invention relates to an overload clutch device of an electric hammer and the electric hammer.

Background

Electric hammers have been widely used in the fields of construction, home decoration, construction, etc., mainly for drilling holes in concrete, floor slabs, brick walls and stone. The electric hammer is based on electric drill and has one piston driven by motor and with crankshaft connecting rod and one cylinder to compress air reciprocally, so that the air pressure inside the cylinder changes periodically and the changed air pressure drives the hammer inside the cylinder to strike the drill bit reciprocally. Because the drill bit of the electric hammer also generates rapid reciprocating motion along the axial direction of the electric drill rod while rotating, the electric hammer can rapidly punch holes on materials such as cement concrete, stone and the like with high brittleness.

Due to complex working conditions, the electric hammer can cause the phenomenon that a drill bit is stuck at times during operation, and can damage transmission parts and burn a motor in serious cases; in addition, after the drill bit is stuck, the motor can continue to work, a large reverse torque force can be generated on the drill bit, and the large torque force can be reacted to the body of an operator to injure the operator. The existing overload protection device is characterized in that a front pressing plate and a rear pressing plate compress a transmission torsion force through elastic elements, and when the overload protection device is overloaded, the front pressing plate and the rear pressing plate slip mutually, so that the overload protection is realized.

Disclosure of Invention

The invention aims to overcome the defect that an overload protection device of an electric hammer in the prior art frequently shakes the electric hammer when a drill bit is stuck, and provides an overload clutch device of the electric hammer and the electric hammer.

The invention solves the technical problems through the following technical scheme:

an overload clutch apparatus of an electric hammer, comprising:

the front clutch plate is provided with a plurality of tooth grooves, and the tooth grooves are annularly arranged on one end surface of the front clutch plate;

the rear clutch plate is provided with a plurality of gear teeth, the gear teeth are annularly arranged on one end face of the rear clutch plate, the gear teeth and the tooth grooves are arranged in a one-to-one correspondence mode, the gear teeth are meshed with the tooth grooves and can slide into or slide out of the tooth grooves along the circumferential direction of the front clutch plate, and the tooth top width of the gear teeth along the circumferential direction is not more than 1/2 of the length of the tooth grooves along the circumferential direction;

the elastic element is used for applying acting force for pressing the front clutch plate to the rear clutch plate;

when the counterforce generated by the relative rotation of the front clutch plate and the rear clutch plate is not larger than the acting force exerted on the front clutch plate by the elastic element, the rear clutch plate can drive the front clutch plate to synchronously rotate;

when the reaction force generated by the relative rotation of the front clutch plate and the rear clutch plate is greater than the acting force exerted on the front clutch plate by the elastic element, the gear teeth slide out of the previous tooth socket and slide into the next tooth socket, so that the front clutch plate slides in the direction away from the rear clutch plate.

In this scheme, this overload clutch sets up to be less than 1/2 of tooth's socket along the length of circumferential direction through the tooth top width of the teeth of a cogwheel along the circumferential direction, when the reaction force that produces of clutch plate and back clutch plate relative rotation is greater than the effort that elastic element applyed on the clutch plate in the front (transship promptly), can not immediately with the inner wall butt of next tooth's socket behind the teeth of a cogwheel roll-off tooth's socket, and just can with the inner wall butt of tooth's socket after the distance of the at least 2 times tooth top width of need slip, make the teeth of a cogwheel and the frequency of tooth's socket contact reduce 1/2 at least, correspondingly reduce the vibration of production, avoid preceding clutch plate and the violent vibration that the back clutch plate continuously dropout brought from this, improve user's operation experience.

Preferably, the tooth socket has a transmission inclined surface at the front end of the tooth socket, the transmission inclined surface is abutted with the tooth surface of the tooth, and the inclination angle of the transmission inclined surface relative to the bottom surface of the tooth socket is determined according to the output load of the overload clutch device and the acting force exerted on the front clutch plate by the elastic element.

In this scheme, preceding clutch plate and back clutch plate come the transmission through the frictional force between the flank of tooth of transmission inclined plane and teeth of a cogwheel, when the reaction force that current clutch plate and back clutch plate relative rotation produced is less than frictional force, preceding clutch plate and back clutch plate keep synchronous rotation, when the reaction force that current clutch plate and back clutch plate relative rotation produced is greater than frictional force (transship promptly), preceding clutch plate and back clutch plate produce relative slip, and then realize forming the dropout, the torsion of motor output does not convey anterior drill bit department, form the protection to machine and operator.

Preferably, the tooth socket further has a transition bevel located at a rear end of the tooth socket, the transition bevel is used for guiding the tooth to slide into the tooth socket from an outside of the tooth socket, and an inclination angle of the transition bevel relative to the tooth socket bottom surface is smaller than an inclination angle of the transmission bevel relative to the tooth socket bottom surface.

In this scheme, adopt above-mentioned structural style, form buffer structure, be convenient for the teeth of a cogwheel smooth slip in the tooth's socket, reduce the vibration and the impact of overload clutch when transshipping.

Preferably, the front clutch plate is provided with a transition plane, the transition plane is arranged between the adjacent tooth sockets, the gear teeth slide out from the previous tooth socket and slide into the next tooth socket through the transition plane, and the length of the transition plane is not less than the tooth crest width of the gear teeth.

In this scheme, when the reaction force that current clutch plate and back clutch plate relative rotation produced is greater than the effort that elastic element applyed on the clutch plate in the front (transshipping promptly), the teeth of a cogwheel can not immediately with the inner wall butt of next tooth's socket after the roll-off of last tooth's socket, and need slide the transition plane, the transition inclined plane, the tooth's socket, just at last with the transmission inclined plane butt of tooth's socket, the gliding stroke of the teeth of a cogwheel is greater than the tooth top width of 3 times teeth of a cogwheel, make the teeth of a cogwheel and the frequency of tooth's socket contact further reduce, correspondingly reduce the vibration that overload clutch device produced, avoid preceding clutch plate and the violent vibration that the back clutch plate continuously drops off and bring from this, improve user's operation experience.

Preferably, the rear clutch plate is provided with a through hole, a cylinder of the electric hammer is arranged in the through hole in a penetrating mode, the rear clutch plate can rotate relative to the cylinder, an annular flange is arranged on the outer side of the through hole, the gear teeth are located on the outer side of the annular flange, the height of the gear teeth is lower than that of the annular flange, and the outer side of the annular flange abuts against the inner side of the transition plane of the front clutch plate.

In this solution, the annular flange is used to constrain the transition plane in the radial direction of the overload clutch, preventing the front and rear clutch plates from swinging in the radial direction. When the front clutch plate and the rear clutch plate are released and then return to the initial position state, the annular flange guides the gear teeth to be clamped into the gear grooves, and the situation that the gear teeth are difficult to be clamped into the gear grooves is avoided. In a further alternative, an annular collar can also be provided on the end face of the front clutch plate, inside the transition plane, the outer side of the annular collar being intended to abut against the inner side of the gear teeth.

Preferably, the middle part of preceding separation and reunion board has the holding hole, the inner wall in holding hole has bellied drive division, be provided with the sliding tray on the outer peripheral face of the cylinder of electric hammer, the sliding tray is followed the axial direction of cylinder extends the setting, the cylinder wears to locate the holding hole, the drive division inlays to be located the sliding tray can be followed the sliding tray slides, preceding separation and reunion board passes through the drive division inlays to be located the sliding tray drives the cylinder rotates.

In the scheme, when the clutch is not overloaded, the front clutch plate is connected with the rear clutch plate through the acting force exerted by the elastic element, then the clutch plate synchronously rotates, and the front clutch plate drives the cylinder to rotate; when the overload occurs, the front clutch plate slides towards the direction far away from the rear clutch plate to form tripping, and the front clutch plate does not rotate along with the rear clutch plate.

The electric hammer comprises a motor, an impact transmission mechanism, a rotating transmission mechanism, an air cylinder assembly and the overload clutch device of the electric hammer, wherein the motor drives the air cylinder assembly to rotate through the rotating transmission mechanism and the overload clutch device, and the motor also impacts a drill bit of the air cylinder assembly in a reciprocating manner through the impact transmission mechanism.

In this scheme, this electric hammer receives overload clutch's protection, and when the drill bit card was died, preceding clutch plate produced relative slip with back clutch plate, and then formed the dropout, and the torsion of motor output does not convey anterior drill bit department, forms the protection to electric hammer and operator.

Preferably, the cylinder assembly includes a cylinder, the rotation transmission mechanism includes a large gear, a bevel gear shaft, a large bevel gear and a connecting sleeve, the large bevel gear and the connecting sleeve are both sleeved on the cylinder and can rotate relative to the cylinder, the large gear is installed at one end of the bevel gear shaft and is meshed with a rotor gear of the motor, the other end of the bevel gear shaft is meshed with the large bevel gear, and two ends of the connecting sleeve are respectively connected to the large bevel gear and the rear clutch plate.

In this scheme, adopt above-mentioned structural style for the transmission is steady, compact structure. The connecting sleeve is used for reducing the impact of vibration generated by the front clutch plate and the rear clutch plate on the large bevel gear when the connecting sleeve is overloaded, prolonging the service life of gear engagement, increasing the length of the cylinder, correspondingly increasing the stroke of the piston and improving the impact strength of the drill bit.

Preferably, the rotation transmission mechanism further comprises an elastic component, and the elastic component applies an acting force for pressing the connecting sleeve on the large bevel gear.

In the scheme, the structure is adopted, the connecting sleeve is prevented from being separated from the big bevel gear, the transmission reliability is improved,

preferably, the impact transmission mechanism comprises a pinion, an eccentric shaft, an eccentric wheel, a connecting rod and a piston, wherein the pinion is installed at one end of the eccentric shaft and is engaged with the rotor teeth of the motor, the eccentric wheel is installed at the other end of the eccentric shaft, two ends of the connecting rod are respectively connected to the eccentric wheel and the piston, and the piston is positioned in the cylinder and can slide along the cylinder in a reciprocating manner;

the eccentric shaft and the bevel gear shaft are arranged in parallel and are positioned on two sides of rotor teeth of the motor.

In this scheme, this electric hammer passes through eccentric wheel and connecting rod complex mode and turns into the reciprocating sliding of piston with the rotation of motor for atmospheric pressure in the cylinder changes, and then produces the impact to the drill bit. The eccentric shaft and the bevel gear shaft are arranged on two sides of the rotor teeth of the motor in parallel, so that the rotor teeth are balanced in stress and stable in transmission.

On the basis of the common knowledge in the field, the above preferred conditions can be combined randomly to obtain the preferred embodiments of the invention.

The positive progress effects of the invention are as follows: this overload clutch sets up 1/2 that is less than tooth's socket along the length of circumferential direction through the tooth top width with the teeth of a cogwheel, when the reaction force that produces of current clutch plate and back clutch plate relative rotation is greater than the effort that elastic element applyed on the clutch plate in the front (transship promptly), the teeth of a cogwheel can not immediately with the inner wall butt of next tooth's socket after the roll-off of last tooth's socket, and just can with the inner wall butt of tooth's socket after the distance of the at least 2 times tooth top width of need slip, make the teeth of a cogwheel reduce 1/2 with the frequency of tooth's socket contact at least, correspondingly, reduce the vibration of production, thereby avoid preceding clutch plate and the violent vibration that the back clutch plate continuously the dropout brought, user's operation experience is improved.

Drawings

Fig. 1 is a schematic diagram of an internal structure of an electric hammer according to a preferred embodiment of the present invention.

FIG. 2 is a schematic view of the engagement structure of the front clutch plate and the rear clutch plate according to a preferred embodiment of the present invention.

FIG. 3 is a schematic structural view of a front clutch plate according to a preferred embodiment of the present invention.

FIG. 4 is a schematic structural diagram of the rear clutch plate according to a preferred embodiment of the present invention.

Description of reference numerals:

motor 1

Rotor tooth 2

Gearwheel 3

Bevel gear shaft 4

Big bevel gear 5

Connecting sleeve 6

Elastic member 7

Rear clutch plate 8

Gear teeth 81

Via 82

Annular flange 83

Steel wire retainer ring 9

Front clutch plate 10

Tooth slot 101

Drive ramp 102

Transition bevel 103

Transition plane 104

Accommodation hole 105

Drive unit 106

Elastic element 11

Gasket 12

Cylinder 13

Impact hammer 14

Impact bar 15

Steel ball 16

Steel ball 17

Rotating sleeve 18

Pinion 19

Eccentric shaft 20

Connecting rod 21

Piston 22

Drill bit 23

Eccentric wheel 24

Impact transmission mechanism 31

Rotation transmission mechanism 32

Cylinder assembly 33

Overload clutch device 34

Tooth tip width 100

Gullet length 200

Detailed Description

The present invention will be more clearly and completely described below by way of examples and with reference to the accompanying drawings, but the present invention is not limited thereto.

As shown in fig. 1 to 4, the present embodiment discloses an overload clutch apparatus of an electric hammer, the overload clutch apparatus 34 including a front clutch plate 10, a rear clutch plate 8 and an elastic member 11. The front clutch plate 10 is provided with a plurality of tooth grooves 101, the tooth grooves 101 are annularly arranged on one end face of the front clutch plate 10, the rear clutch plate 8 is provided with a plurality of gear teeth 81, the gear teeth 81 are annularly arranged on one end face of the rear clutch plate 8, the gear teeth 81 and the tooth grooves 101 are arranged in a one-to-one correspondence mode, and the gear teeth 81 are meshed with the tooth grooves 101 and can slide into or slide out of the tooth grooves 101 along the circumferential direction of the front clutch plate 10. Wherein the elastic element 11 is used to exert a force pressing the front clutch plate 10 against the rear clutch plate 8. In the present embodiment, the elastic element 11 is a spring. The elastic element 11 is sleeved on the cylinder 13, one end of the elastic element 11 is abutted against the front clutch plate 10, and the other end of the elastic element 11 is abutted against the gasket 12. The gasket 12 is fixed to the cylinder by the wire retainer 9. In this embodiment, a plurality of tooth spaces 101 are uniformly spaced at an end surface of the front clutch plate 10, and a plurality of gear teeth 81 are uniformly spaced at an end surface of the rear clutch plate 8, so as to facilitate smooth transmission.

When the counterforce generated by the relative rotation of the front clutch plate 10 and the rear clutch plate 8 is not greater than the acting force exerted on the front clutch plate 10 by the elastic element 11 (without overload), the rear clutch plate 8 can drive the front clutch plate 10 to synchronously rotate. When the reaction force generated by the relative rotation of the front clutch plate 10 and the rear clutch plate 8 is larger than the action force exerted on the front clutch plate 10 by the elastic element 11 (overload), the gear teeth 81 slide out from the previous gear groove 101 and slide into the next gear groove 101, so that the front clutch plate 10 slides in the direction away from the rear clutch plate 8, and then the tripping is formed.

In order to reduce frequent shaking caused by the electric hammer when the drill bit 23 is locked, the tooth crest width 100 of the gear teeth 81 in the circumferential direction is set to be not more than 1/2 of the tooth socket length 200 of the gear teeth 101 in the circumferential direction, when the reaction force generated by relative rotation of the front clutch plate 10 and the rear clutch plate 8 is larger than the action force exerted on the front clutch plate 10 by the elastic element 11, the gear teeth 81 cannot be immediately abutted against the inner wall of the next gear tooth 101 after sliding out from the previous gear tooth 101, but can be abutted against the inner wall of the gear tooth 101 after sliding for at least 2 times of the tooth crest width, so that the frequency of contact between the gear teeth 81 and the gear tooth 101 is reduced by at least 1/2, and accordingly, the generated vibration is reduced, violent vibration caused by continuous tripping of the front clutch plate 10 and the rear clutch plate 8 is avoided, and the operation experience of a user is improved.

As shown in fig. 2 and 3, the tooth groove 101 of the front clutch plate 10 has a transmission slope 102, the transmission slope 102 is located at the front end of the tooth groove 101, and the transmission slope 102 abuts against the tooth surface of the gear tooth 81 when the motor 1 rotates. Front clutch plate 10 and rear clutch plate 8 are driven by friction between drive ramps 102 and the tooth flanks of gear teeth 81. When the reaction force that current clutch plate 10 and back clutch plate 8 relative rotation produced is less than frictional force (not transshipping), preceding clutch plate 10 and back clutch plate 8 keep synchronous rotation, when the reaction force that current clutch plate 10 and back clutch plate 8 relative rotation produced is greater than frictional force (transshipping), preceding clutch plate 10 and back clutch plate 8 produce relative slip, and then realize forming the dropout, the torsion of motor 1 output does not convey anterior drill bit 23 department, form the protection to machine and operator.

Wherein the inclination angle of the transmission slope 102 with respect to the bottom surface of the tooth groove 101 is determined according to the output load of the overload clutch apparatus 34 and the force applied to the front clutch plate 10 by the elastic member 11. If the torque of the drill bit 23 is increased, the inclination angle of the transmission inclined plane 102 is increased; if the torque of the drill bit 23 is to be reduced, the inclination angle of the transmission bevel 102 is reduced. If the force applied by the elastic element 11 is large, the inclination angle of the transmission slope 102 can be reduced to release the hammer under a small load, and the torque output by the bit 23 can also be adjusted by changing the force applied by the elastic element 11. In addition, the height of the drive ramps also affects the output load of the drill bit, with higher heights providing greater output loads and lower heights providing lesser output loads. Thus, the angle of inclination and the height of the drive ramps 102 can be set as desired by the user.

As shown in fig. 2 and 3, the tooth slot 101 further has a transition bevel 103, the transition bevel 103 is located at the rear end of the tooth slot 101, and the transition bevel 103 is used for guiding the gear teeth 81 to slide into the tooth slot 101 from the outside of the tooth slot 101, so as to form a buffer structure, facilitate the gear teeth 81 to slide into the tooth slot 101 smoothly, and reduce the vibration and impact of the overload clutch device 34 during overload.

Because the transition inclined plane is used for smooth transition of the gear teeth 81, the inclination angle of the transition inclined plane 103 relative to the bottom surface of the tooth groove 101 is smaller than that of the transmission inclined plane 102 relative to the bottom surface of the tooth groove 101, so that a buffer effect is achieved, and impact between the gear teeth 81 and the tooth groove 101 is reduced.

As shown in fig. 2 and 3. In order to further improve the buffering effect, transition planes 104 are arranged on the front clutch plate 10, the transition planes 104 are arranged between adjacent tooth spaces 101, the gear teeth 81 slide out of the previous tooth space 101 and slide into the next tooth space 101 through the transition planes 104, and the length of the transition planes 104 is not less than the tooth crest width 100 of the gear teeth 81. When the reaction force generated by the relative rotation of the front clutch plate 10 and the rear clutch plate 8 is greater than the action force exerted on the front clutch plate 10 by the elastic element 11 (overload), the gear teeth 81 slide out from the previous gear groove 101 and cannot be immediately abutted against the inner wall of the next gear groove 101, and need to slide across the transition plane 104, the transition inclined plane 103 and the gear groove 101, and finally abut against the transmission inclined plane 102 of the next gear groove 101, the sliding stroke of the gear teeth 81 is greater than three times of the tooth top width 100 of the gear teeth 81, so that the frequency of the contact between the gear teeth 81 and the gear groove 101 is further reduced, and the vibration generated by the overload clutch device 34 is correspondingly reduced, thereby avoiding the violent vibration caused by the continuous tripping of the front clutch plate 10 and the rear clutch plate 8, and improving the operation experience of a user.

The front clutch plate 10 is sleeved on the cylinder 13 through a containing hole 105 in the middle part and rotates synchronously with the cylinder 13. The inner wall of the accommodating hole 105 is provided with a convex driving part 106, the outer peripheral surface of the cylinder 13 of the electric hammer is provided with a sliding groove, the sliding groove extends along the axial direction of the cylinder 13, the driving part 106 is embedded in the sliding groove and can slide along the sliding groove, and the front clutch plate 10 is embedded in the sliding groove through the driving part 106 to drive the cylinder 13 to rotate. In this embodiment, drive division and sliding tray one-to-one set up, and the quantity of drive division is a plurality of, and the even interval of a plurality of drive divisions sets up the inner wall at clutch plate in front, and the clutch plate and cylinder atress in front of being convenient for make are even, and the transmission is steady.

When the overload is not generated, the front clutch plate 10 is connected with the rear clutch plate 8 through the acting force exerted by the elastic element 11, then the clutch plate 8 synchronously rotates, and the front clutch plate 10 drives the cylinder 13 to rotate. When the overload occurs, the counterforce generated by the relative rotation of the front clutch plate 10 and the rear clutch plate 8 pushes the front clutch plate 10 to slide in the direction away from the rear clutch plate 8 to form tripping, and at the moment, the front clutch plate 10 does not rotate along with the rear clutch plate 8.

The rear clutch plate 8 is sleeved on the cylinder 13 through a through hole 82 in the middle and can rotate relative to the cylinder 13. When the drill bit 23 is stuck, the motor 1 can continuously output to protect the motor 1 because the front clutch plate 10 and the rear clutch plate 8 are tripped.

As shown in fig. 4, in order to accurately reset the front clutch plate 10 and the rear clutch plate 8 after being disengaged, an annular flange 83 is provided outside the through hole 82, the gear teeth 81 are located outside the annular flange 83, the height of the gear teeth 81 is lower than that of the annular flange 83, the outside of the annular flange 83 abuts against the inside of the transition plane 104 of the front clutch plate 10, and the front clutch plate 10 and the rear clutch plate 8 are prevented from swinging in the radial direction. When the front clutch plate 10 is released from the rear clutch plate 8 and then returned to the initial position state, the annular flange 83 guides the gear teeth 81 to be engaged in the tooth grooves 101 without causing a situation where the gear teeth 81 are difficult to be engaged in the tooth grooves 101. In other alternative embodiments, an annular flange may also be provided on the end face of the front clutch plate, inside the transition plane, the outer side of the annular flange being intended to abut against the inner side of the gear teeth.

As shown in fig. 1, the embodiment further discloses an electric hammer, which comprises a motor 1, an impact transmission mechanism 31, a rotation transmission mechanism 32, a cylinder assembly 33 and an overload clutch device 34 of the electric hammer, wherein the motor 1 drives the cylinder assembly 33 to rotate through the rotation transmission mechanism 32 and the overload clutch device 34, and the motor 1 also impacts a drill bit 23 of the cylinder assembly 33 in a reciprocating manner through the impact transmission mechanism 31. The electric hammer is protected by an overload clutch device 34, when the drill bit 23 is stuck, the front clutch plate 10 and the rear clutch plate 8 of the overload clutch device 34 slide relatively to form tripping, and the torque output by the motor 1 is not transmitted to the front drill bit 23, so that the electric hammer and an operator are protected.

The cylinder assembly 33 includes a cylinder 13, a striking rod 15, a rotary sleeve 18, a drill bit 23, and a hammer 14. The impact rod 15 is mounted within the swivel sleeve 18 to form a swivel sleeve assembly. The impact rod 15 is limited by a steel ball 17. The rotating sleeve assembly is arranged in the air cylinder 13 and limited by a steel ball 16. The drill bit 23 is arranged in the rotary sleeve 18 and is positioned at the front end of the impact rod 15, and the drill bit 23 rotates synchronously with the rotary sleeve 18. A ram 14 is slidably mounted in the cylinder 13 at the rear end of the striking rod 15.

Wherein, the rotation transmission mechanism 32 comprises a gearwheel 3, a bevel gear shaft 4, a big bevel gear 5 and a connecting sleeve 6. The large bevel gear 5 and the connecting sleeve 6 are sleeved on the cylinder 13 and can rotate relative to the cylinder 13. The big gear 3 is installed to the one end of bevel gear axle 4, and big gear 3 meshes with rotor tooth 2 of motor 1, and the other end of bevel gear axle 4 meshes with big bevel gear 5, and the both ends of adapter sleeve 6 block respectively connects in big bevel gear 5 and back clutch plate 8 for the transmission is steady, compact structure.

The rotation transmission process of the electric hammer is as follows: motor 1 rotates, and rotor tooth 2 drives gear wheel 3 and rotates, and gear wheel 3 drives bevel gear shaft 4 and rotates, and bevel gear shaft 4 drives big bevel gear 5 and rotates, and big bevel gear 5 drives adapter sleeve 6 and rotates, and adapter sleeve 6 drives the back clutch plate 8 rotation that transships clutch device 34, and clutch plate 10 rotates before back clutch plate 8 drives, and preceding clutch plate 10 drives cylinder 13 and rotates, and cylinder 13 drives drill bit 23 and rotates. The connecting sleeve 6 is arranged between the rear clutch plate 8 and the large bevel gear 5 and used for reducing the impact of vibration generated by the front clutch plate 10 and the rear clutch plate 8 on the large bevel gear 5 in overload, prolonging the service life of gear engagement, increasing the length of the cylinder 13, correspondingly increasing the stroke of the piston 22 and improving the impact strength of the drill bit 23.

In order to prevent the connecting sleeve 6 from separating from the large bevel gear 5 and improve the transmission reliability, the rotation transmission mechanism 32 further comprises an elastic component 7, and the elastic component 7 applies a force for pressing the connecting sleeve 6 to the large bevel gear 5. In the present embodiment, the elastic member 7 is an elastic washer.

The impact transmission mechanism 31 includes a pinion 19, an eccentric shaft 20, an eccentric 24, a connecting rod 21, and a piston 22. One end of the eccentric shaft 20 is provided with a pinion 19, the pinion 19 is engaged with the rotor teeth 2 of the motor 1, the other end of the eccentric shaft 20 is provided with an eccentric wheel 24, and both ends of the connecting rod 21 are respectively connected to the eccentric wheel 24 and the piston 22. The rotation of the motor 1 is converted into the reciprocating sliding of the piston 22 through the matching of the eccentric wheel 24 and the connecting rod 21, and a compact impact transmission mechanism 31 is formed.

The piston 22 is located in the cylinder 13 and is capable of reciprocating sliding along the cylinder 13, and a closed space is formed between the piston 22 and the hammer ram 14. When the piston 22 slides reciprocally, the air pressure in the cylinder 13 changes, so that the hammer 14 makes reciprocating impact on the drill bit 23.

Wherein, eccentric shaft 20 and bevel gear shaft 4 parallel arrangement just are located the both sides of the rotor tooth 2 of motor 1 for rotor tooth 2 atress is balanced, and the transmission is steady.

The impact transmission process of the electric hammer is as follows: the motor 1 rotates, the rotor teeth 2 drive the pinion 19 to rotate, the pinion 19 drives the eccentric shaft 20 to rotate, the eccentric shaft 20 drives the eccentric wheel 24 to rotate, the eccentric wheel 24 drives the connecting rod 21 to reciprocate, and the connecting rod 21 drives the piston 22 to slide in a reciprocating manner.

If the drill bit 23 is suddenly locked in the working state of the electric hammer, the overload clutch device 34 can automatically cut off the torque force between the motor 1 and the drill bit 23 to form a protection mechanism, and the electric hammer can automatically return to the initial state after the drill bit 23 is pulled out.

While specific embodiments of the invention have been described above, it will be appreciated by those skilled in the art that this is by way of example only, and that the scope of the invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the spirit and scope of the invention, and these changes and modifications are within the scope of the invention.