Overload clutch for an electric hammer and electric hammer

Abstract

The application discloses an overload clutch device of an electric hammer and the electric hammer. The overload clutch device comprises a front clutch plate, a plurality of tooth grooves are arranged on an end surface of the front clutch plate; a rear clutch plate, a plurality of gear teeth are arranged on an end surface of the rear clutch plate, the gear teeth are arranged one by one corresponding to the tooth grooves, the gear teeth are engaged in the tooth grooves and can slide into or out of the tooth grooves along a circumferential direction of the front clutch plate, wherein a tooth top width of the gear teeth along the circumferential direction is not greater than 1 / 2 of a length of the tooth groove along the circumferential direction; and an elastic element, the elastic element is used for applying an action force for pressing the front clutch plate to the rear clutch plate. When the overload clutch device is overloaded, the gear tooth slides out of the tooth groove and does not immediately abut against an inner wall of the next tooth groove, but needs to slide a distance of at least 2 times the tooth top width before being able to abut against the inner wall of the tooth groove, so that the frequency of the gear tooth contacting the tooth groove is reduced by at least 1 / 2, and the vibration generated by the overload clutch device is correspondingly reduced.

Description

Technical Field

[0001] This invention relates to an overload clutch device for an electric hammer and the electric hammer itself. Background Technology

[0002] Electric hammer drills are widely used in construction, home improvement, and other fields, primarily for drilling holes in concrete, floor slabs, brick walls, and stone. An electric hammer drill is based on an electric drill, but with the addition of a piston driven by an electric motor and a crankshaft connecting rod. This piston compresses air reciprocally within a cylinder, causing periodic changes in air pressure. These changing air pressures drive a hammer within the cylinder to repeatedly strike the drill bit. Because the drill bit in an electric hammer drill also generates rapid reciprocating motion along the axial direction of the drill rod while rotating, it can quickly drill holes in brittle materials such as cement concrete and stone.

[0003] Due to complex working conditions, the drill bit of the electric hammer may jam intermittently during operation, which can severely damage transmission components and burn out the motor. Furthermore, even when the drill bit is jammed, the motor continues to operate, generating significant reverse torque on the drill bit. This immense torque can react against the operator, causing injury. Existing overload protection devices use elastic elements to press the front and rear pressure plates together to transmit torque. When overloaded, the front and rear pressure plates slip against each other, thus achieving overload protection. However, due to the toothed meshing between the front and rear pressure plates, the motor's power output still causes the electric hammer to frequently vibrate violently, resulting in a poor operating experience for the operator. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the defect of the overload protection device of the electric hammer in the prior art, which causes frequent vibration of the electric hammer when the drill bit is stuck, and to provide an overload clutch device for the electric hammer and the electric hammer.

[0005] The present invention solves the above-mentioned technical problems through the following technical solution:

[0006] An overload clutch device for an electric hammer, comprising:

[0007] A front clutch plate having multiple toothed grooves, the multiple toothed grooves being arranged in a ring around one end face of the front clutch plate;

[0008] The rear clutch plate has multiple teeth, which are arranged in a ring on one end face of the rear clutch plate. The teeth are arranged in a one-to-one correspondence with the tooth grooves. The teeth mesh with the tooth grooves and can slide into or out of the tooth grooves along the circumferential direction of the front clutch plate. The tooth tip width along the circumferential direction is not greater than 1 / 2 of the length of the tooth groove along the circumferential direction.

[0009] An elastic element, the elastic element being used to apply a force that presses the front clutch plate against the rear clutch plate;

[0010] When the reaction force generated by the relative rotation of the front clutch plate and the rear clutch plate is not greater than the force exerted by the elastic element on the front clutch plate, the rear clutch plate can drive the front clutch plate to rotate synchronously.

[0011] When the reaction force generated by the relative rotation of the front clutch plate and the rear clutch plate is greater than the force exerted by the elastic element on the front clutch plate, the gear tooth slides out from the previous tooth groove and into the next tooth groove, so that the front clutch plate slides away from the rear clutch plate.

[0012] In this solution, the overload clutch device sets the tooth tip width along the circumferential direction to be less than 1 / 2 of the tooth groove length along the circumferential direction. When the reaction force generated by the relative rotation of the front clutch plate and the rear clutch plate is greater than the force applied by the elastic element to the front clutch plate (i.e., overload), the tooth does not immediately abut against the inner wall of the next tooth groove after sliding out of the tooth groove. Instead, it needs to slide at least twice the tooth tip width before it can abut against the inner wall of the tooth groove. This reduces the frequency of tooth contact with the tooth groove by at least 1 / 2, thereby reducing the vibration generated. This avoids the severe vibration caused by the continuous disengagement of the front clutch plate and the rear clutch plate, and improves the user's operating experience.

[0013] Preferably, the tooth groove has a transmission ramp, the transmission ramp is located at the front end of the tooth groove, the transmission ramp abuts against the tooth surface of the gear tooth, and the inclination angle of the transmission ramp relative to the bottom surface of the tooth groove is determined according to the output load of the overload clutch device and the force exerted by the elastic element on the front clutch plate.

[0014] In this design, the front and rear clutch plates are driven by friction between the transmission ramp and the tooth surfaces of the gears. When the reaction force generated by the relative rotation of the front and rear clutch plates is less than the friction force, the front and rear clutch plates rotate synchronously. When the reaction force generated by the relative rotation of the front and rear clutch plates is greater than the friction force (i.e., overload), the front and rear clutch plates slide relative to each other, thereby achieving disengagement. The torque output by the motor is not transmitted to the front drill bit, thus protecting the machine and the operator.

[0015] Preferably, the tooth groove also has a transition slope located at the rear end of the tooth groove. The transition slope is used to guide the gear tooth to slide from the outside of the tooth groove into the tooth groove. The inclination angle of the transition slope relative to the bottom surface of the tooth groove is smaller than the inclination angle of the transmission slope relative to the bottom surface of the tooth groove.

[0016] In this solution, the above-mentioned structural form is adopted to form a buffer structure, which facilitates the smooth sliding of the gear teeth into the tooth groove and reduces the vibration and impact of the overload clutch device under overload.

[0017] Preferably, the front clutch plate has a transition plane disposed between adjacent tooth slots, the tooth slides out of the previous tooth slot and slides into the next tooth slot through the transition plane, and the length of the transition plane is not less than the tooth tip width of the tooth.

[0018] In this design, when the reaction force generated by the relative rotation of the front and rear clutch plates is greater than the force applied to the front clutch plate by the elastic element (i.e., overload), the gear teeth do not immediately abut against the inner wall of the next gear groove after sliding out from the previous groove. Instead, they need to slide over the transition plane, transition slope, and groove before finally abutting against the transmission slope of the groove. The sliding stroke of the gear teeth is greater than three times the tooth tip width, which further reduces the frequency of contact between the gear teeth and the groove, thereby reducing the vibration generated by the overload clutch device. This avoids the severe vibration caused by the continuous disengagement of the front and rear clutch plates and improves the user's operating experience.

[0019] Preferably, the rear clutch plate has a through hole through which the cylinder of the electric hammer passes, the rear clutch plate is rotatable relative to the cylinder, the outer side of the through hole has an annular flange, the gear teeth are located on the outer side of the annular flange, and the height of the gear teeth is lower than the height of the annular flange, the outer side of the annular flange abuts against the inner side of the transition plane of the front clutch plate.

[0020] In this design, the annular flange is used to restrict the transition plane in the radial direction of the overload clutch device, preventing the front and rear clutch plates from swinging radially. When the front and rear clutch plates disengage and then return to their initial positions, the annular flange guides the gear teeth to engage in the tooth grooves, preventing the teeth from failing to engage. In other alternative designs, the annular flange can also be located on the end face of the front clutch plate, inside the transition plane, with its outer side abutting against the inner side of the gear teeth.

[0021] Preferably, the front clutch plate has a receiving hole in the middle, and the inner wall of the receiving hole has a protruding driving part. The outer peripheral surface of the cylinder of the electric hammer is provided with a sliding groove, which extends along the axial direction of the cylinder. The cylinder passes through the receiving hole, and the driving part is embedded in the sliding groove and can slide along the sliding groove. The front clutch plate drives the cylinder to rotate through the driving part embedded in the sliding groove.

[0022] In this design, when there is no overload, the front clutch plate is connected to the rear clutch plate by the force applied by the elastic element, and the rear clutch plate rotates synchronously, and the front clutch plate then drives the cylinder to rotate; when there is an overload, the front clutch plate slides away from the rear clutch plate, forming a disengagement, and at this time the front clutch plate does not rotate with the rear clutch plate.

[0023] An electric hammer includes a motor, an impact transmission mechanism, a rotation transmission mechanism, a cylinder assembly, and an overload clutch device for the electric hammer. The motor drives the cylinder assembly to rotate through the rotation transmission mechanism and the overload clutch device. The motor also reciprocates to impact the drill bit of the cylinder assembly through the impact transmission mechanism.

[0024] In this design, the electric hammer is protected by an overload clutch device. When the drill bit jams, the front clutch plate and the rear clutch plate slide relative to each other, thus disengaging the clutch. The torque output by the motor is not transmitted to the front drill bit, thus protecting the electric hammer and the operator.

[0025] Preferably, the cylinder assembly includes a cylinder, and the rotational 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 fitted onto the cylinder and can rotate relative to the cylinder. One end of the bevel gear shaft is equipped with the large gear, which meshes with the rotor teeth of the motor. The other end of the bevel gear shaft meshes with the large bevel gear. The two ends of the connecting sleeve are respectively connected to the large bevel gear and the rear clutch plate.

[0026] In this solution, the aforementioned structural form ensures smooth transmission and a compact structure. This connecting sleeve is used to reduce the impact of vibrations generated by the front and rear clutch plates on the large bevel gears under overload conditions, thereby improving the service life of gear meshing. It also increases the length of the cylinder, correspondingly increasing the piston stroke and enhancing the impact strength of the drill bit.

[0027] Preferably, the rotary transmission mechanism further includes an elastic component that applies a force to press the connecting sleeve against the large bevel gear.

[0028] In this solution, the above-mentioned structural form is adopted to prevent the connecting sleeve from separating from the large bevel gear, thereby improving the reliability of the transmission.

[0029] Preferably, the impact transmission mechanism includes a pinion, an eccentric shaft, an eccentric wheel, a connecting rod, and a piston. One end of the eccentric shaft is equipped with a pinion, which meshes with the rotor teeth of the motor. The other end of the eccentric shaft is equipped with an eccentric wheel. The two ends of the connecting rod are respectively connected to the eccentric wheel and the piston. The piston is located inside the cylinder and can reciprocate along the cylinder.

[0030] The eccentric shaft is arranged parallel to the bevel gear shaft and located on both sides of the rotor teeth of the motor.

[0031] In this design, the electric hammer converts the motor's rotation into the reciprocating sliding of the piston through the cooperation of an eccentric wheel and connecting rod. This causes a change in the air pressure within the cylinder, which in turn impacts the drill bit. The eccentric shaft and the bevel gear shaft are arranged parallel to each other on both sides of the motor's rotor teeth, ensuring balanced force on the rotor teeth and smooth transmission.

[0032] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0033] The positive and progressive effects of this invention are as follows: By setting the tooth tip width along the circumferential direction of the gear teeth to be less than 1 / 2 of the length of the tooth groove along the circumferential direction, when the reaction force generated by the relative rotation of the front clutch plate and the rear clutch plate is greater than the force applied to the front clutch plate by the elastic element (i.e., overload), the gear teeth will not immediately abut against the inner wall of the next tooth groove after sliding out of the previous tooth groove. Instead, they need to slide a distance of at least twice the tooth tip width before they can abut against the inner wall of the tooth groove. This reduces the frequency of contact between the gear teeth and the tooth groove by at least 1 / 2, thereby reducing the vibration generated. This avoids the severe vibration caused by the continuous disengagement of the front clutch plate and the rear clutch plate, and improves the user's operating experience. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the internal structure of an electric hammer according to a preferred embodiment of the present invention.

[0035] Figure 2 This is a schematic diagram of the engagement structure of the front clutch plate and the rear clutch plate according to a preferred embodiment of the present invention.

[0036] Figure 3 This is a schematic diagram of the front clutch plate according to a preferred embodiment of the present invention.

[0037] Figure 4 This is a schematic diagram of the rear clutch plate according to a preferred embodiment of the present invention.

[0038] Explanation of reference numerals in the attached figures:

[0039] Motor 1

[0040] Rotor teeth 2

[0041] Large Gear 3

[0042] Bevel gear shaft 4

[0043] Large bevel 5

[0044] Connecting sleeve 6

[0045] Elastic component 7

[0046] Rear clutch plate 8

[0047] Gear 81

[0048] Via 82

[0049] Annular flange 83

[0050] Wire retaining ring 9

[0051] Front clutch plate 10

[0052] Gear 101

[0053] Transmission inclined plane 102

[0054] Transition slope 103

[0055] Transition plane 104

[0056] Receiving hole 105

[0057] Drive Unit 106

[0058] Elastic element 11

[0059] Washer 12

[0060] Cylinder 13

[0061] Hammer 14

[0062] Impact rod 15

[0063] 16 steel balls

[0064] Steel Ball 17

[0065] 18 sets

[0066] Small Gear 19

[0067] eccentric shaft 20

[0068] Link 21

[0069] Piston 22

[0070] Drill bit 23

[0071] 24 Eccentric Wheel

[0072] Impact transmission mechanism 31

[0073] Rotary transmission mechanism 32

[0074] Cylinder assembly 33

[0075] Overload clutch device 34

[0076] Tooth tip width 100

[0077] Tooth groove length 200 Detailed Implementation

[0078] The present invention will be described more clearly and completely below by way of embodiments and in conjunction with the accompanying drawings, but the present invention is not limited to the scope of the embodiments described herein.

[0079] like Figures 1-4 As shown, this embodiment discloses an overload clutch device for an electric hammer. The overload clutch device 34 includes a front clutch plate 10, a rear clutch plate 8, and an elastic element 11. The front clutch plate 10 has multiple toothed grooves 101 arranged around one end face of the front clutch plate 10. The rear clutch plate 8 has multiple gear teeth 81 arranged around one end face of the rear clutch plate 8. The gear teeth 81 are arranged in a one-to-one correspondence with the toothed grooves 101, and the gear teeth 81 mesh with the toothed grooves 101 and can slide into or out of the toothed grooves 101 in the circumferential direction of the front clutch plate 10. The elastic element 11 is used to apply a force to press the front clutch plate 10 against the rear clutch plate 8. In this embodiment, the elastic element 11 is a spring. The elastic element 11 is sleeved on the cylinder 13, with one end of the elastic element 11 abutting against the front clutch plate 10 and the other end abutting against the washer 12. The washer 12 is fixed to the cylinder by the wire retaining ring 9. In this embodiment, multiple tooth grooves 101 are evenly spaced on one end face of the front clutch plate 10, and multiple gear teeth 81 are evenly spaced on one end face of the rear clutch plate 8, which facilitates smooth transmission.

[0080] 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 force applied to 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 rotate synchronously. 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 force applied to the front clutch plate 10 by the elastic element 11 (overload), the gear teeth 81 slide out from the previous tooth groove 101 and slide into the next tooth groove 101, so that the front clutch plate 10 slides away from the rear clutch plate 8, thereby forming a disengagement.

[0081] To reduce the frequent vibrations caused by the electric hammer when the drill bit 23 is stuck, the tooth tip width 100 of the gear tooth 81 in the circumferential direction is set to be no greater than 1 / 2 of the tooth groove length 200 of the tooth groove 101 in 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 greater than the force applied to the front clutch plate 10 by the elastic element 11, the gear tooth 81 will not immediately abut against the inner wall of the next tooth groove 101 after sliding out of the previous tooth groove 101. Instead, it needs to slide at least twice the tooth tip width before it can abut against the inner wall of the tooth groove 101. This reduces the frequency of contact between the gear tooth 81 and the tooth groove 101 by at least 1 / 2, thereby reducing the vibrations generated. This avoids the severe vibrations caused by the continuous disengagement of the front clutch plate 10 and the rear clutch plate 8, and improves the user's operating experience.

[0082] like Figure 2 and Figure 3As shown, the tooth groove 101 of the front clutch plate 10 has a transmission inclined surface 102, which is located at the front end of the tooth groove 101. When the motor 1 rotates, the transmission inclined surface 102 abuts against the tooth surface of the gear tooth 81. The front clutch plate 10 and the rear clutch plate 8 are driven by the friction between the transmission inclined surface 102 and the tooth surface of the gear tooth 81. When the reaction force generated by the relative rotation of the front clutch plate 10 and the rear clutch plate 8 is less than the friction force (no overload), the front clutch plate 10 and the rear clutch plate 8 rotate synchronously. 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 friction force (overload), the front clutch plate 10 and the rear clutch plate 8 slide relative to each other, thereby achieving disengagement. The torque output by the motor 1 is not transmitted to the front drill bit 23, thus protecting the machine and the operator.

[0083] The inclination angle of the drive ramp 102 relative to the bottom surface of the tooth groove 101 is determined based on the output load of the overload clutch device 34 and the force applied to the front clutch plate 10 by the elastic element 11. To increase the torque of the drill bit 23, the inclination angle of the drive ramp 102 is increased; to decrease the torque of the drill bit 23, the inclination angle of the drive ramp 102 is decreased. If the force applied by the elastic element 11 is large, the inclination angle of the drive ramp 102 can be reduced to achieve disengagement of the electric hammer under small load conditions. Alternatively, the output torque of the drill bit 23 can be adjusted by changing the force applied by the elastic element 11. In addition, the height of the drive ramp also affects the output load of the drill bit; the higher the height, the greater the output load, and the lower the height, the smaller the output load. Therefore, the inclination angle and height of the drive ramp 102 can be set according to user needs.

[0084] like Figure 2 and Figure 3 As shown, the tooth groove 101 also has a transition slope 103, which is located at the rear end of the tooth groove 101. The transition slope 103 is used to guide the gear teeth 81 to slide from the outside of the tooth groove 101 into the tooth groove 101, forming a buffer structure, which facilitates the smooth sliding of the gear teeth 81 into the tooth groove 101 and reduces the vibration and impact of the overload clutch device 34 under overload.

[0085] Since the transition ramp is used for the smooth transition of gear teeth 81, the inclination angle of the transition ramp 103 relative to the bottom surface of the tooth groove 101 is smaller than the inclination angle of the transmission ramp 102 relative to the bottom surface of the tooth groove 101, which plays a buffering role and reduces the impact between gear teeth 81 and tooth groove 101.

[0086] like Figure 2 and Figure 3As shown. In order to further improve the buffering effect, a transition plane 104 is provided on the front clutch plate 10. The transition plane 104 is located between adjacent tooth grooves 101. The gear tooth 81 slides out from the previous tooth groove 101 and slides into the next tooth groove 101 through the transition plane 104. The length of the transition plane 104 is not less than the tooth tip width 100 of the gear tooth 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 force applied to the front clutch plate 10 by the elastic element 11 (overload), the gear tooth 81 does not immediately abut against the inner wall of the next gear groove 101 after sliding out from the previous tooth groove 101. Instead, it needs to slide over the transition plane 104, the transition slope 103, and the tooth groove 101 before finally abutting against the transmission slope 102 of the next tooth groove 101. The sliding stroke of the gear tooth 81 is greater than three times the tooth tip width 100 of the gear tooth 81, which further reduces the frequency of contact between the gear tooth 81 and the tooth groove 101, thereby reducing the vibration generated by the overload clutch device 34. This avoids the severe vibration caused by the continuous disengagement of the front clutch plate 10 and the rear clutch plate 8, and improves the user's operating experience.

[0087] The front clutch plate 10 is fitted onto the cylinder 13 through a central receiving hole 105 and rotates synchronously with the cylinder 13. The inner wall of the receiving hole 105 has a protruding driving part 106. A sliding groove is provided 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 it. The front clutch plate 10, through the driving part 106 embedded in the sliding groove, drives the cylinder 13 to rotate. In this embodiment, the driving part and the sliding groove are arranged in a one-to-one correspondence. There are multiple driving parts, which are evenly spaced on the inner wall of the front clutch plate to ensure even force distribution on the front clutch plate and the cylinder, resulting in smooth transmission.

[0088] When not under load, the front clutch plate 10 is connected to 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, forming a disengagement. At this time, the front clutch plate 10 does not rotate with the rear clutch plate 8.

[0089] The rear clutch plate 8 is fitted onto the cylinder 13 through the central through hole 82 and can rotate relative to the cylinder 13. When the drill bit 23 jams, the motor 1 can still continue to output power because the front clutch plate 10 and the rear clutch plate 8 are disengaged, thus protecting the motor 1.

[0090] like Figure 4As shown, to ensure accurate repositioning of the front clutch plate 10 and rear clutch plate 8 after disengagement, an annular flange 83 is provided on the outer side of the through hole 82. Gear teeth 81 are located on the outer side of the annular flange 83, and the height of the gear teeth 81 is lower than the height of the annular flange 83. The outer side of the annular flange 83 abuts against the inner side of the transition plane 104 of the front clutch plate 10, preventing the front clutch plate 10 and rear clutch plate 8 from swinging radially. When the front clutch plate 10 and rear clutch plate 8 return to their initial position after disengagement, the annular flange 83 guides the gear teeth 81 to engage with the tooth groove 101, preventing the gear teeth 81 from being difficult to engage with the tooth groove 101. In other alternative embodiments, the annular flange can also be provided on the end face of the front clutch plate, located inside the transition plane, with the outer side of the annular flange abutting against the inner side of the gear teeth.

[0091] like Figure 1 As shown, this embodiment also discloses an electric hammer, which includes a motor 1, an impact transmission mechanism 31, a rotation transmission mechanism 32, a cylinder assembly 33, and an overload clutch device 34. The motor 1 drives the cylinder assembly 33 to rotate through the rotation transmission mechanism 32 and the overload clutch device 34. The motor 1 also reciprocates the impact of 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 jams, the front clutch plate 10 and the rear clutch plate 8 of the overload clutch device 34 slide relative to each other, thereby disengaging the clutch. The torque output by the motor 1 is not transmitted to the front drill bit 23, thus protecting the electric hammer and the operator.

[0092] The cylinder assembly 33 includes a cylinder 13, an impact rod 15, a rotating sleeve 18, a drill bit 23, and a hammer 14. The impact rod 15 is installed within the rotating sleeve 18, forming a rotating sleeve assembly. The impact rod 15 is limited by a steel ball 17. The rotating sleeve assembly is installed within the cylinder 13 and limited by a steel ball 16. The drill bit 23 is installed within the rotating sleeve 18 and located at the front end of the impact rod 15; the drill bit 23 rotates synchronously with the rotating sleeve 18. The hammer 14 is slidably installed within the cylinder 13 and located at the rear end of the impact rod 15.

[0093] The rotary transmission mechanism 32 includes a large gear 3, a bevel gear shaft 4, a large bevel gear 5, and a connecting sleeve 6. Both the large bevel gear 5 and the connecting sleeve 6 are fitted onto the cylinder 13 and can rotate relative to it. One end of the bevel gear shaft 4 is fitted with the large gear 3, which meshes with the rotor teeth 2 of the motor 1. The other end of the bevel gear shaft 4 meshes with the large bevel gear 5. Both ends of the connecting sleeve 6 are respectively engaged with the large bevel gear 5 and the rear clutch plate 8, resulting in smooth transmission and a compact structure.

[0094] The rotational transmission process of the electric hammer is as follows: Motor 1 rotates, rotor teeth 2 drive 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 cylinder 13 to rotate, and the cylinder 13 drives the drill bit 23 to rotate. The connecting sleeve 6 is installed between the rear clutch plate 8 and the large bevel gear 5 to reduce the impact of vibrations generated by the front clutch plate 10 and the rear clutch plate 8 on the large bevel gear 5 under overload conditions, improving the service life of the gear mesh. It also increases the length of the cylinder 13, correspondingly increasing the stroke of the piston 22 and improving the impact strength of the drill bit 23.

[0095] To prevent the connecting sleeve 6 from separating from the large bevel gear 5 and improve the reliability of the transmission, the rotation transmission mechanism 32 also includes an elastic component 7, which applies a force to press the connecting sleeve 6 against the large bevel gear 5. In this embodiment, the elastic component 7 is an elastic washer.

[0096] The impact transmission mechanism 31 includes a pinion 19, an eccentric shaft 20, an eccentric wheel 24, a connecting rod 21, and a piston 22. The pinion 19 is mounted on one end of the eccentric shaft 20, meshing with the rotor teeth 2 of the motor 1. The eccentric wheel 24 is mounted on the other end of the eccentric shaft 20. The two ends of the connecting rod 21 are connected to the eccentric wheel 24 and the piston 22, respectively. Through the cooperation of the eccentric wheel 24 and the connecting rod 21, the rotation of the motor 1 is converted into the reciprocating sliding of the piston 22, forming a compact impact transmission mechanism 31.

[0097] The piston 22 is located inside the cylinder 13 and can slide back and forth along the cylinder 13, forming a sealed space between the piston 22 and the hammer 14. When the piston 22 slides back and forth, the air pressure inside the cylinder 13 changes, causing the hammer 14 to reciprocate and impact the drill bit 23.

[0098] The eccentric shaft 20 is arranged parallel to the bevel gear shaft 4 and located on both sides of the rotor teeth 2 of the motor 1, so that the rotor teeth 2 are subjected to force balance and the transmission is smooth.

[0099] 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 move back and forth, and the connecting rod 21 drives the piston 22 to slide back and forth.

[0100] If the drill bit 23 suddenly jams during operation, the overload clutch device 34 can automatically cut off the torque between the motor 1 and the drill bit 23, forming a protection mechanism. After the drill bit 23 is removed, the electric hammer can automatically return to its initial state.

[0101] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. An overload clutch device for an electric hammer, characterized in that, It includes: A front clutch plate having multiple toothed grooves, the multiple toothed grooves being arranged in a ring around one end face of the front clutch plate; The rear clutch plate has multiple teeth, which are arranged in a ring on one end face of the rear clutch plate. The teeth are arranged in a one-to-one correspondence with the tooth grooves. The teeth mesh with the tooth grooves and can slide into or out of the tooth grooves along the circumferential direction of the front clutch plate. The tooth tip width along the circumferential direction is not greater than 1 / 2 of the length of the tooth groove along the circumferential direction. An elastic element, the elastic element being used to apply a force that presses the front clutch plate against 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 greater than the force exerted by the elastic element on the front clutch plate, the rear clutch plate can drive the front clutch plate to rotate synchronously. When the reaction force generated by the relative rotation of the front clutch plate and the rear clutch plate is greater than the force exerted by the elastic element on the front clutch plate, the gear tooth slides out from the previous tooth groove and into the next tooth groove, so that the front clutch plate slides away from the rear clutch plate.

2. The overload clutch device for the electric hammer as described in claim 1, characterized in that, The tooth groove has a transmission inclined surface, which is located at the front end of the tooth groove. The transmission inclined surface abuts against the tooth surface of the gear tooth. The inclination angle of the transmission inclined surface relative to the bottom surface of the tooth groove is determined according to the output load of the overload clutch device and the force exerted on the front clutch plate by the elastic element.

3. The overload clutch device for the electric hammer as described in claim 2, characterized in that, The tooth groove also has a transition slope located at the rear end of the tooth groove. The transition slope is used to guide the gear teeth to slide from the outside of the tooth groove into the tooth groove. The inclination angle of the transition slope relative to the bottom surface of the tooth groove is smaller than the inclination angle of the transmission slope relative to the bottom surface of the tooth groove.

4. The overload clutch device for the electric hammer as described in claim 1, characterized in that, The front clutch plate has a transition plane, which is located between adjacent tooth slots. The tooth slides out of the previous tooth slot, through the transition plane, and into the next tooth slot. The length of the transition plane is not less than the tooth tip width.

5. The overload clutch device for the electric hammer as described in claim 4, characterized in that, The rear clutch plate has a through hole through which the cylinder of the electric hammer passes. The rear clutch plate can rotate relative to the cylinder. The outer side of the through hole has an annular flange. The gear teeth are located on the outer side of the annular flange, and the height of the gear teeth is lower than the height of the annular flange. The outer side of the annular flange abuts against the inner side of the transition plane of the front clutch plate.

6. The overload clutch device for the electric hammer as described in any one of claims 1-5, characterized in that, The front clutch plate has a receiving hole in the middle, and the inner wall of the receiving hole has a protruding driving part. The outer peripheral surface of the cylinder of the electric hammer is provided with a sliding groove, which extends along the axial direction of the cylinder. The cylinder passes through the receiving hole, and the driving part is embedded in the sliding groove and can slide along the sliding groove. The front clutch plate drives the cylinder to rotate through the driving part embedded in the sliding groove.

7. An electric hammer, characterized in that, The electric hammer includes a motor, an impact transmission mechanism, a rotation transmission mechanism, a cylinder assembly, and an overload clutch device for the electric hammer as described in any one of claims 1-6. The motor drives the cylinder assembly to rotate through the rotation transmission mechanism and the overload clutch device. The motor also reciprocates to impact the drill bit of the cylinder assembly through the impact transmission mechanism.

8. The electric hammer as described in claim 7, characterized in that, The cylinder assembly includes a cylinder, and the rotational 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 fitted onto the cylinder and can rotate relative to the cylinder. The large gear is installed at one end of the bevel gear shaft, and the large gear meshes with the rotor teeth of the motor. The other end of the bevel gear shaft meshes with the large bevel gear. The two ends of the connecting sleeve are respectively connected to the large bevel gear and the rear clutch plate.

9. The electric hammer as described in claim 8, characterized in that, The rotational transmission mechanism further includes an elastic component that applies a force to press the connecting sleeve against the large bevel gear.

10. The electric hammer as described in claim 8, characterized in that, The impact transmission mechanism includes a pinion, an eccentric shaft, an eccentric wheel, a connecting rod, and a piston. A pinion is installed at one end of the eccentric shaft, and the pinion meshes with the rotor teeth of the motor. An eccentric wheel is installed at the other end of the eccentric shaft. The two ends of the connecting rod are respectively connected to the eccentric wheel and the piston. The piston is located inside the cylinder and can slide back and forth along the cylinder. The eccentric shaft is arranged parallel to the bevel gear shaft and located on both sides of the rotor teeth of the motor.

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