CN113681516B - Overload clutch device of electric hammer and electric hammer - Google Patents

Abstract

This invention discloses an overload clutch device for an electric hammer and the electric hammer itself. The overload clutch device includes: a front clutch plate having multiple toothed grooves arranged around one end face of the front clutch plate; a rear clutch plate having multiple gear teeth arranged around one end face of the rear clutch plate, with each gear tooth corresponding to a toothed groove, the gear teeth meshing with the toothed grooves and being able to slide into or out of the toothed grooves along the circumferential direction of the front clutch plate, wherein the tooth tip width along the circumferential direction is not greater than 1/2 of the length of the toothed groove along the circumferential direction; and an elastic element for applying a force to press the front clutch plate against the rear clutch plate. When the overload clutch device is overloaded, after the gear teeth slide out of the toothed grooves, they do not immediately abut against the inner wall of the next toothed groove, but need to slide a distance of at least twice the tooth tip width before abutting against the inner wall of the toothed groove, thereby reducing the frequency of contact between the gear teeth and the toothed grooves by at least 1/2, and correspondingly reducing the vibration generated by the overload clutch device.

Description

Overload clutch device of electric hammer and electric hammer

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., and are mainly used for drilling holes in concrete, floor slabs, brick walls, and stone materials. The electric hammer is based on electric drill, and has one piston with crankshaft and connecting rod driven by motor to compress air reciprocally in one cylinder to make the air pressure in the cylinder change periodically. Because the drill bit of the electric hammer rotates and simultaneously generates quick reciprocating motion along the axial direction of the electric drill rod, the electric hammer can quickly punch holes in cement concrete, stone and other materials with high brittleness.

Because of complex working conditions, the electric hammer can sometimes have the phenomenon of drill bit blocking during operation, and can damage transmission parts and burn out a motor when serious, and the motor can continue to work after the drill bit is blocked, and can have large reverse torsion on the drill bit, and the huge torsion can be reacted on an operator to cause the operator to be injured. The existing overload protection device is characterized in that the front pressing plate and the rear pressing plate compress tightly transmission torsion through the elastic element, when overload occurs, the front pressing plate and the rear pressing plate slide mutually, so that overload protection is realized, and because of the tooth-shaped matching relationship between the front pressing plate and the rear pressing plate, the power output of the motor can frequently generate severe shaking for the electric hammer, and poor operation experience is brought to an operator.

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 blocked, and provides an overload clutch device of the electric hammer and the electric hammer.

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

an overload clutch device 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 face of the front clutch plate;

The rear clutch plate is provided with a plurality of gear teeth, the gear teeth are arranged on one end face of the rear clutch plate in a ring mode, the gear teeth are arranged in one-to-one correspondence with the tooth grooves, the gear teeth are meshed with the tooth grooves and can slide in 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 greater than 1/2 of the length of the tooth grooves along the circumferential direction;

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

When the reaction force 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 larger than the acting force exerted on the front clutch plate by the elastic element, the gear teeth slide out of the last tooth slot and slide into the next tooth slot, so that the front clutch plate slides in a direction away from the rear clutch plate.

In this scheme, this overload clutch is through setting the tooth top width along circumference direction to be less than 1/2 of tooth's socket along circumference direction's length, when the reaction force that preceding clutch plate and back clutch plate relative rotation produced is greater than the effort that elastic element applyed on preceding clutch plate (i.e. overload), the inner wall butt with next tooth's socket can not immediately be followed to the tooth after the tooth roll-off tooth socket, and can with the inner wall butt of tooth's socket after the distance that needs to slide at least 2 times tooth top width for the frequency of tooth and tooth's socket contact reduces at least 1/2, reduces the vibration that produces correspondingly, avoid preceding clutch plate and back clutch plate to trip the violent vibration that brings constantly from this, improve user's operation experience.

Preferably, the tooth slot is provided with a transmission inclined plane, the transmission inclined plane is positioned at the front end of the tooth slot, the transmission inclined plane is in abutting connection with the tooth surface of the tooth, and the inclination angle of the transmission inclined plane relative to the bottom surface of the tooth slot 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 are transmitted through the frictional force between the flank of tooth of transmission inclined plane and teeth of a cogwheel, and when the reaction force that preceding clutch plate and back clutch plate relative rotation produced was less than frictional force, preceding clutch plate and back clutch plate keep rotating in step, and when the reaction force that preceding clutch plate and back clutch plate relative rotation produced was greater than frictional force (i.e. overload), preceding clutch plate and back clutch plate produced relative slip, and then realized forming the dropout, and the torsion of motor output does not convey anterior drill bit department, forms the protection to machine and operator.

Preferably, the tooth slot is further provided with a transition inclined plane, the transition inclined plane is located at the rear end of the tooth slot, the transition inclined plane is used for guiding the gear teeth to slide into the tooth slot from the outside of the tooth slot, and the inclination angle of the transition inclined plane relative to the bottom surface of the tooth slot is smaller than that of the transmission inclined plane relative to the bottom surface of the tooth slot.

In the scheme, the buffer structure is formed by adopting the structure, so that gear teeth can slide into the tooth grooves smoothly, and vibration and impact of the overload clutch device during overload are reduced.

Preferably, the front clutch plate is provided with a transition plane, the transition plane is arranged between adjacent tooth grooves, the gear teeth slide out from the last tooth groove to slide into the next tooth groove through the transition plane, and the length of the transition plane is not less than the tooth top 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 preceding clutch plate (i.e. transshipping), the teeth of a cogwheel can not immediately with the inner wall butt of next tooth groove after the roll-off of last tooth groove, and need roll-over transition plane, transition inclined plane, tooth groove, just last with the transmission inclined plane butt of tooth groove, the gliding stroke of teeth of a cogwheel is greater than 3 times the tooth top width of teeth of a cogwheel for the frequency of teeth of a cogwheel and tooth groove contact further reduces, reduces the vibration that overload clutch produced correspondingly, avoid preceding clutch plate and back clutch plate to trip the violent vibration that brings continually from this, improve user's operation experience.

Preferably, the rear clutch plate is provided with a through hole, the cylinder of the electric hammer penetrates through the through hole, the rear clutch plate can rotate relative to the cylinder, the outer side of the through hole is provided with an annular flange, the gear teeth are positioned 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 is abutted to the inner side of the transition plane of the front clutch plate.

In this solution, the annular flange is used to limit the transition plane in the radial direction of the overload clutch device, preventing the front clutch plate and the rear clutch plate from swinging in the radial direction. When the front clutch plate and the rear clutch plate are released and then restored to the initial position state, the annular flange guide gear teeth are clamped into the tooth grooves, and the situation that the gear teeth are difficult to clamp into the tooth grooves is avoided. In other alternatives, an annular flange can also be provided on the end face of the front clutch plate, on the inner side of the transition plane, the outer side of which is intended to abut the inner side of the gear teeth.

Preferably, the middle part of preceding clutch plate has the accommodation hole, the inner wall of accommodation 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 and sets up, the cylinder wears to locate the accommodation hole, drive division inlays to be located the sliding tray and can follow the sliding tray slides, preceding clutch plate passes through drive division inlays to be located the sliding tray drives the cylinder rotates.

In the scheme, when overload is not caused, the front clutch plate is connected with the rear clutch plate through the acting force exerted by the elastic element and then rotates synchronously, the front clutch plate drives the air cylinder to rotate, and when overload is caused, the front clutch plate slides in a direction away from the rear clutch plate to form tripping, and at the moment, the front clutch plate does not rotate subsequently.

The utility model provides an electric hammer, the electric hammer includes motor, impact drive mechanism, rotation drive mechanism, cylinder subassembly and foretell electric hammer's overload clutch, the motor passes through rotation drive mechanism overload clutch drives cylinder subassembly rotates, the motor is still passed through impact drive mechanism reciprocal impact cylinder subassembly's drill bit.

In this scheme, this electric hammer receives overload clutch's protection, and when the drill bit card was dead, preceding clutch plate and back clutch plate produced relative slip, 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 comprises a cylinder, the rotation transmission mechanism comprises a large gear, a bevel gear shaft, large bevel gears and a connecting sleeve, the large bevel gears and the connecting sleeve are all sleeved on the cylinder and can rotate relative to the cylinder, the large gear is installed at one end of the bevel gear shaft, the large gear is meshed with a rotor gear of the motor, the other end of the bevel gear shaft is meshed with the large bevel gears, and two ends of the connecting sleeve are respectively connected with the large bevel gears and the rear clutch plate.

In the scheme, the structure is adopted, so that the transmission is stable, and the structure is compact. 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 in overload, 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 a acting force for pressing the connecting sleeve on the big bevel gear.

In the scheme, the structure is adopted to prevent the connecting sleeve from being separated from the large bevel gear, improve the transmission reliability,

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 meshed with 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 with the eccentric wheel and the piston, and the piston is positioned in the cylinder and can slide back and forth along the cylinder;

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

In this scheme, this electric hammer is through eccentric wheel and connecting rod complex mode with the rotation of motor change into the reciprocal slip of piston for the 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 stressed and balanced, and the transmission is stable.

On the basis of conforming to the common knowledge in the field, the above preferred conditions can be arbitrarily combined to obtain the preferred examples of the invention.

The overload clutch device has the positive advantages that the tooth top width of the gear teeth in the circumferential direction is set to be smaller than 1/2 of the length of the gear teeth in the circumferential direction, when the reaction force generated by the relative rotation of the front clutch plate and the rear clutch plate is larger than the acting force exerted on the front clutch plate by the elastic element (namely overload), the gear teeth can not immediately abut against the inner wall of the next gear teeth after sliding out of the last gear teeth, and can abut against the inner wall of the gear teeth after sliding for at least 2 times of the distance of the tooth top width, so that the contact frequency of the gear teeth and the gear teeth is reduced by at least 1/2, the generated vibration is correspondingly reduced, and the severe vibration caused by continuous tripping of the front clutch plate and the rear clutch plate is avoided, and the operation experience of a user is improved.

Drawings

Fig. 1 is a schematic view showing 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 view of a front clutch plate according to a preferred embodiment of the present invention.

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

Reference numerals illustrate:

Electric machine 1

Rotor teeth 2

Big gear 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 9

Front clutch plate 10

Tooth slot 101

Transmission bevel 102

Transition slope 103

Transition plane 104

Accommodation hole 105

A driving part 106

Elastic element 11

Gasket 12

Cylinder 13

Ram 14

Impact bar 15

Steel ball 16

Steel ball 17

Swivel 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 34

Tip width 100

Tooth slot length 200

Detailed Description

The invention will now be more fully described by way of example only and with reference to the accompanying drawings, but the invention is not thereby limited to the scope of the examples described.

As shown in fig. 1 to 4, the present embodiment discloses an overload clutch device of an electric hammer, and the overload clutch device 34 includes a front clutch plate 10, a rear clutch plate 8, and an elastic member 11. The front clutch plate 10 has a plurality of tooth grooves 101, the plurality of tooth grooves 101 are annularly arranged on one end surface of the front clutch plate 10, the rear clutch plate 8 has a plurality of gear teeth 81, the gear teeth 81 are annularly arranged on one end surface of the rear clutch plate 8, the gear teeth 81 are arranged in one-to-one correspondence with the tooth grooves 101, 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. The elastic element 11 is used for applying a force for pressing the front clutch plate 10 to the rear clutch plate 8. In the present embodiment, the elastic element 11 is a spring. The elastic element 11 is sleeved on the air 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 means of a wire retainer 9. In this embodiment, the plurality of tooth grooves 101 are uniformly spaced on an end surface of the front clutch plate 10, and the plurality of teeth 81 are uniformly spaced on an end surface of the rear clutch plate 8, so that smooth transmission is facilitated.

When the reaction force 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 (no 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 greater than the acting force exerted on the front clutch plate 10 by the elastic element 11 (overload), the gear teeth 81 slide out of the previous tooth slot 101 and slide into the next tooth slot 101 so that the front clutch plate 10 slides away from the rear clutch plate 8, and thus the trip is formed.

In order to reduce frequent vibration caused by the electric hammer when the drill bit 23 is jammed, the tooth top width 100 of the gear teeth 81 along the circumferential direction is set to be not more than 1/2 of the tooth groove length 200 of the tooth groove 101 along the circumferential direction, 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 acting force exerted on the front clutch plate 10 by the elastic element 11, the gear teeth 81 do not immediately abut against the inner wall of the next tooth groove 101 after sliding out from the previous tooth groove 101, and can abut against the inner wall of the tooth groove 101 after sliding for at least 2 times the distance of the tooth top width, so that the contact frequency of the gear teeth 81 and the tooth groove 101 is reduced by at least 1/2, and the generated vibration is correspondingly reduced, thereby avoiding severe vibration caused by continuous tripping of the front clutch plate 10 and the rear clutch plate 8 and improving the operation experience of users.

As shown in fig. 2 and 3, the tooth grooves 101 of the front clutch plate 10 have a transmission inclined surface 102, the transmission inclined surface 102 is located at the front end of the tooth groove 101, and when the motor 1 rotates, the transmission inclined surface 102 abuts against the tooth surfaces of the gear teeth 81. The front clutch plate 10 and the rear clutch plate 8 are driven by friction between the driving bevel 102 and the flanks 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 smaller than the friction force (no overload), the front clutch plate 10 and the rear clutch plate 8 keep rotating synchronously, 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 friction force (overload), the front clutch plate 10 and the rear clutch plate 8 slide relatively, and further the tripping is realized, the torque output by the motor 1 is not transmitted to the front drill bit 23, and the protection is formed for the machine and an operator.

The inclination angle of the transmission bevel 102 relative to the bottom surface of the tooth slot 101 is determined according to the output load of the overload clutch 34 and the acting force exerted on the front clutch plate 10 by the elastic element 11. If the torque of the drill bit 23 is to be increased, the inclination angle of the transmission bevel 102 is increased, and if the torque of the drill bit 23 is to be decreased, the inclination angle of the transmission bevel 102 is decreased. If the force applied by the elastic element 11 is large, in order to realize the tripping of the electric hammer under the condition of small load, the inclination angle of the transmission inclined plane 102 can be reduced, and the torque output by the drill bit 23 can be adjusted by changing the force applied by the elastic element 11. In addition, the height of the transmission inclined plane also affects the output load of the drill bit, and the higher the height is, the larger the output load is, and the lower the height is, the smaller the output load is. Accordingly, the inclination angle and the height of the driving bevel 102 can be set according to the user's needs.

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

Since 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 slot 101 is smaller than the inclination angle of the transmission inclined plane 102 relative to the bottom surface of the tooth slot 101, so that a buffer effect is achieved, and the impact between the gear teeth 81 and the tooth slot 101 is reduced.

As shown in fig. 2 and 3. In order to further improve the cushioning effect, a transition plane 104 is provided on the front clutch plate 10, the transition plane 104 is provided between adjacent tooth grooves 101, the gear teeth 81 slide from the previous tooth groove 101 into the next tooth groove 101 through the transition plane 104, and the length of the transition plane 104 is not less than the tooth top 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 larger than the acting force exerted on the front clutch plate 10 by the elastic element 11 (overload), the gear teeth 81 do not immediately abut against the inner wall of the next gear slot 101 after sliding out of the previous gear slot 101, but need to slide through the transition plane 104, the transition inclined plane 103 and the gear slot 101 and finally abut against the transmission inclined plane 102 of the next gear slot 101, the sliding stroke of the gear teeth 81 is larger than three times of the gear tooth width 100 of the gear teeth 81, so that the contact frequency of the gear teeth 81 and the gear slots 101 is further reduced, the vibration generated by the overload clutch device 34 is correspondingly reduced, and the severe 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.

The front clutch plate 10 is sleeved on the cylinder 13 through the accommodating hole 105 in the middle and synchronously rotates along with the cylinder 13. The inner wall of the accommodation hole 105 is provided with a convex driving part 106, a sliding groove is arranged on the outer circumferential surface of the cylinder 13 of the electric hammer, 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 a plurality of drive division even interval sets up the inner wall at preceding clutch plate, is convenient for make preceding clutch plate and cylinder atress even, and the transmission is steady.

When not overloaded, the front clutch plate 10 is connected with the rear clutch plate 8 by the force applied by the elastic element 11, and then the clutch plate 8 rotates synchronously, and the front clutch plate 10 drives the cylinder 13 to rotate. When overloaded, the reaction force 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 away from the rear clutch plate 8, so as to form tripping, and at this time, the front clutch plate 10 does not rotate subsequently to the clutch plate 8.

The rear clutch plate 8 is sleeved on the cylinder 13 through the 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 also continuously output as the front clutch plate 10 and the rear clutch plate 8 form tripping, so that the motor 1 is protected.

As shown in fig. 4, in order to accurately reset the front clutch plate 10 and the rear clutch plate 8 after releasing, an annular flange 83 is provided on the outer side of the through hole 82, the gear teeth 81 are positioned on the outer side of the annular flange 83, the height of the gear teeth 81 is lower than that of the annular flange 83, and the outer side of the annular flange 83 abuts against the inner side of a transition plane 104 of the front clutch plate 10 to prevent the front clutch plate 10 and the rear clutch plate 8 from swinging in the radial direction. When the front clutch plate 10 and the rear clutch plate 8 are released and then restored to the initial position state, the annular flange 83 guides the gear teeth 81 to be clamped into the tooth grooves 101, and the situation that the gear teeth 81 are difficult to be clamped into the tooth grooves 101 is avoided. In other alternative embodiments, an annular flange may also be provided on the end face of the front clutch plate, on the inside of the transition plane, the outside of which is intended to abut the inside of the gear teeth.

As shown in fig. 1, the present embodiment also discloses an electric hammer including 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 reciprocally impacts the drill bit 23 of the cylinder assembly 33 through the impact transmission mechanism 31. The electric hammer is protected by the overload clutch device 34, when the drill bit 23 is blocked, the front clutch plate 10 and the rear clutch plate 8 of the overload clutch device 34 slide relatively, so that tripping is formed, the torque output by the motor 1 is not transmitted to the position of the front drill bit 23, and the electric hammer and an operator are protected.

The cylinder assembly 33 includes, among other things, the cylinder 13, the impact rod 15, the swivel 18, the drill bit 23, and the ram 14. The impact rod 15 is mounted within a swivel 18 forming a swivel assembly. The impact rod 15 is limited by a steel ball 17. The rotating sleeve assembly is arranged in the cylinder 13 and limited by the steel ball 16. A drill bit 23 is mounted in the swivel 18 at the front end of the impact rod 15, the drill bit 23 rotating synchronously with the swivel 18. The ram 14 is slidably mounted within the cylinder 13 and is located at the rear end of the impact rod 15.

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

The rotation transmission process of the electric hammer is as follows, the motor 1 rotates, the rotor gear 2 drives the large gear 3 to rotate, the large gear 3 drives the bevel gear shaft 4 to rotate, the bevel gear shaft 4 drives the large bevel gear 5 to rotate, the large bevel gear 5 drives the connecting sleeve 6 to rotate, the connecting sleeve 6 drives the rear clutch plate 8 of the overload clutch device 34 to rotate, the rear clutch plate 8 drives the front clutch plate 10 to rotate, the front clutch plate 10 drives the air cylinder 13 to rotate, and the air cylinder 13 drives the drill bit 23 to rotate. The connecting sleeve 6 is arranged between the rear clutch plate 8 and the large bevel gear 5 and is 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 being separated from the big bevel gear 5 and improve the reliability of transmission, the rotation transmission mechanism 32 further comprises an elastic component 7, and the elastic component 7 applies a acting force for pressing the connecting sleeve 6 on the big 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. A pinion 19 is mounted at one end of the eccentric shaft 20, the pinion 19 is meshed with the rotor teeth 2 of the motor 1, an eccentric wheel 24 is mounted at the other end of the eccentric shaft 20, and two ends of the connecting rod 21 are respectively connected with the eccentric wheel 24 and the piston 22. The eccentric wheel 24 is matched with the connecting rod 21 to convert the rotation of the motor 1 into the reciprocating sliding of the piston 22, so that the impact transmission mechanism 31 with compact structure is formed.

The piston 22 is located in the cylinder 13 and can slide reciprocally along the cylinder 13, and a closed space is formed between the piston 22 and the ram 14. When the piston 22 reciprocates, the air pressure in the air cylinder 13 changes, so that the hammer ram 14 generates reciprocating impact to the drill bit 23.

Wherein, eccentric shaft 20 and bevel gear axle 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 reciprocate.

When the drill bit 23 is suddenly blocked in the working state, the overload clutch device 34 can automatically cut off the torsion between the motor 1 and the drill bit 23 to form a protection mechanism, and the electric hammer can automatically recover 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 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 principles and spirit of the invention, but such changes and modifications fall within the scope of the invention.

Claims (10)

1. An overload clutch device of an electric hammer, characterized in that it comprises:

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

The rear clutch plate is provided with a plurality of gear teeth, the gear teeth are arranged on one end face of the rear clutch plate in a ring mode, the gear teeth are arranged in one-to-one correspondence with the tooth grooves, the gear teeth are meshed with the tooth grooves and can slide in 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 greater than 1/2 of the length of the tooth grooves along the circumferential direction;

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

When the reaction force 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 larger than the acting force exerted on the front clutch plate by the elastic element, the gear teeth slide out of the last tooth slot and slide into the next tooth slot, so that the front clutch plate slides in a direction away from the rear clutch plate.

2. The overload clutch apparatus of an electric hammer as claimed in claim 1, wherein the tooth slot has a driving bevel at a front end thereof, the driving bevel abutting against a tooth surface of the tooth, an inclination angle of the driving bevel with respect to a bottom surface of the tooth slot being determined according to 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 of an electric hammer as claimed in claim 2, wherein the tooth slot further has a transition slope at a rear end of the tooth slot, the transition slope being for guiding the tooth to slide into the tooth slot from an outside of the tooth slot, the transition slope having a smaller inclination angle with respect to a bottom surface of the tooth slot than an inclination angle of the transmission slope with respect to the bottom surface of the tooth slot.

4. The overload clutch apparatus of an electric hammer as claimed in claim 1, wherein the front clutch plate has a transition plane provided between adjacent ones of the tooth slots, the tooth teeth sliding from a previous one of the tooth slots through the transition plane into a next one of the tooth slots, a length of the transition plane being not less than a tooth tip width of the tooth teeth.

5. The overload clutch apparatus of claim 4, wherein the rear clutch plate has a through hole through which the 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 at an outer side of the annular flange, and the gear teeth have a height lower than that of the annular flange, and an outer side of the annular flange is abutted to an inner side of a transition plane of the front clutch plate.

6. The overload clutch apparatus of an electric hammer as set forth in any one of claims 1 to 5, wherein the front clutch plate has a receiving hole in a middle portion thereof, a convex driving portion is provided on an inner wall of the receiving hole, a sliding groove is provided on an outer circumferential surface of a cylinder of the electric hammer, the sliding groove is extended 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 is capable of sliding along the sliding groove, and the front clutch plate is inserted into the sliding groove through the driving portion to rotate the cylinder.

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 an overload clutch device of the electric hammer, 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 of claim 7, wherein the cylinder assembly comprises a cylinder, the rotation transmission mechanism comprises a large gear, a bevel gear shaft, a large bevel gear and a connecting sleeve, the large bevel gear and the connecting sleeve are sleeved on the cylinder and can rotate relative to the cylinder, the large gear is installed at one end of the bevel gear shaft, the large gear 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.

9. The electric hammer of claim 8, wherein the rotary drive mechanism further comprises an elastic member that applies a force that compresses the connection sleeve against the large bevel gear.

10. The electric hammer as set forth in claim 8, wherein the impact transmission mechanism comprises a pinion gear, an eccentric shaft, an eccentric wheel, a connecting rod and a piston, wherein the pinion gear is installed at one end of the eccentric shaft, the pinion gear is engaged with the rotor teeth of the motor, the eccentric wheel is installed at the other end of the eccentric shaft, both ends of the connecting rod are respectively connected to the eccentric wheel and the piston, and the piston is located in the cylinder and can slide reciprocally along the cylinder;

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