An electric hammer drill

Abstract

The application discloses an electric hammer drill and belongs to the technical field of drilling equipment. The electric hammer drill comprises a first cutting body, a second cutter head connected to one end of the first cutting body, and a second cutting body detachably connected to the other end of the first cutting body. The second cutting body is connected with a first cutter handle, and the first cutter handle is used for assembling with a drill clamping part. The electric hammer drill has the advantages of long service life, low cost, flexible adjustment and assembly of the electric hammer drill for coping with different drilling conditions, high drilling accuracy and small damage to the periphery of a drilled hole.

Description

Technical Field

[0001] This invention relates to the field of drilling equipment technology, specifically to an electric hammer drill. Background Technology

[0002] Electric hammer drills mainly consist of a motor, gearbox, piston, and drill bit. The motor, after being reduced in speed by the gearbox, drives the piston to reciprocate within the cylinder, generating impact force. Simultaneously, the drill bit, while rotating, is also subjected to periodic impact force, thus achieving efficient drilling and breaking operations. Electric hammer drills are commonly used for drilling into hard materials such as concrete and brick. However, commonly used drill bits are insufficient for drilling into these hard materials. Therefore, the market has seen the emergence of combination drills, such as those with alloy drill bits welded to the drill body. Figure 1 As shown, a first cutting head made of alloy material is provided on the drill body for drilling hard materials such as concrete and masonry. A corresponding existing patent, such as US20240399469A1, discloses a drill bit and a drill cutting tool. The drill bit defines a rotation axis and includes two cutting tool portions located on opposite sides of the rotation axis in the transverse direction. Each cutting tool portion has a rake face, a flank face, and an edge formed between the rake face and the flank face. The rake face of each cutting tool portion is ground to form a grinding profile. The grinding profiles of the two rake faces are different, thereby creating at least a local height difference between the two cutting tools. This can improve drilling accuracy and extend tool life. Multi-flute drills, such as four-flute drills, have also appeared on the market. For example, prior art WO2023064344A1 discloses a drill bit including a body having a first end, a second end, a rotation axis defined by the first and second ends, and a body groove extending along the rotation axis at a helix angle. The drilling tool also includes a cutting head attached to the second end of the body. The cutting head includes a first cutting edge, a second cutting edge, and a cutting head groove. The cutting head groove is defined between the first and second cutting edges. The cutting head groove extends along the axis of rotation at a helix angle. However, the aforementioned prior art has relatively high costs in use, and there is room for improvement in the ease of adjustment of the drill bit to cope with different drilling conditions. Summary of the Invention

[0003] The purpose of this invention is to provide an electric hammer drill that has a long service life and low cost, can be flexibly adjusted and assembled to cope with different drilling conditions, has high drilling accuracy, and causes little damage to the surrounding area of ​​the drilled hole.

[0004] To solve the above-mentioned technical problems, the present invention specifically provides the following technical solution: an electric hammer drill, including a first cutting body, a second cutting head connected to one end of the first cutting body, a second cutting body detachably connected to the other end of the first cutting body, and a first tool holder connected to the second cutting body. The first tool holder is used for assembly with the electric drill clamping component.

[0005] Compared with the prior art, the present application adopts a split assembly scheme, and the worn parts of the second cutter or the first cutting body and the second cutting body can be replaced separately, without scrapping the entire equipment, thereby reducing the use cost, and when facing different drilling targets, the assembly method, drill bit, etc.

[0006] According to an embodiment of the present application, one end of the first cutting body has a concave first groove body, the first groove body penetrates through the two side surfaces of the first cutting body, the bottom of the second cutter has a first mounting block matched with the first groove body, and the first mounting block and the first groove body are respectively provided with corresponding first connecting holes and are matched with first connecting pieces. The first groove body of the first cutting body can be inserted and matched with the first mounting block, which can realize quick disassembly and assembly when replacing the drill bit, especially greatly shortens the drill bit replacement time in special application scenarios, and the insertion and matching method avoids the wear and rust risk of the existing threaded connection, and the first connecting piece ensures the tight connection effect of the insertion and matching, the first connecting piece is a bolt or screw structure, and in addition, after the first groove body and the first mounting block are inserted and matched, the impact stress can be uniformly dispersed on the insertion and matching part when the drill bit is rotated and subjected to periodic impact force in cooperation with the motor during the working process of the electric hammer drill, thereby reducing the fatigue fracture caused by stress concentration, and the overall coaxiality of the first groove body and the first mounting block after insertion and matching can be guaranteed, thereby avoiding drilling deviation.

[0007] The insertion and matching parts are subjected to carburizing and quenching treatment to improve the strength and ensure that the structure after insertion and matching can withstand torque and impact.

[0008] After the first groove body and the first mounting block are inserted and matched, the first connecting piece is screwed into the first connecting hole, which is a threaded hole, thereby realizing the tight connection of the first groove body and the first mounting block, and the connection gap between the second cutter or the first cutting body and the second cutting body is not easy to be blocked, for example, in a mud or dust environment, the threaded connection method is more likely to be blocked and stuck.

[0009] According to an embodiment of the present application, the slot side of the first slot body has a second slot body, the slot bottom of the first slot body has a mounting slot, the first mounting block has a protruding part filling the second slot body, the bottom of the first mounting block has a first elastic member filling the mounting slot, the second slot body cooperates with the protruding part to form a centering effect during the insertion process, to ensure that the coaxiality alignment is achieved simultaneously during the insertion, so that the possibility of hole deflection is reduced during product use, and the second slot body has a guiding installation effect through cooperation with the protruding part during assembly, which shortens the complexity of the insertion installation and shortens the insertion time, wherein the first elastic member is a structure with elastic function, such as a metal spring, an elastic column, etc., which is used for centering and installation guiding during insertion installation, and is also used for absorbing and consuming impact stress transmission during product use, such as the stress transmitted from the second tool head to the first cutting body, which can be partially transmitted to the first elastic member for consumption, to avoid loosening or gap between the two.

[0010] According to an embodiment of the present application, the first cutting body is a rotary body structure and a spiral groove is arranged around the surface, a first plane parallel to the axis of the first cutting body is arranged on the end face adjacent to the second tool head, and the first plane and the spiral groove are smoothly transitioned. The arrangement of the spiral groove on the first cutting body ensures that the drillings can be discharged through the spiral groove during drilling, avoids the accumulation of drillings to block the hole or damage the surrounding structure of the hole, etc., and when a cooling liquid is needed during drilling of individual materials, the cooling liquid can be guided through the spiral groove to enter and contact the second tool head for cooling. The existence of the first plane helps to discharge the drillings generated during drilling of the drill bit to the spiral groove part, and more importantly, the first plane cooperates with the spiral groove to reduce the contact area between the drillings and the hole wall to reduce the drilling friction resistance and improve the drilling efficiency, and during the discharge of the drillings from the drill bit to the spiral groove, the discharge path changes after passing through the first plane, which helps to break the drillings and avoid the occurrence of overlong drilling winding.

[0011] According to an embodiment of the present application, the end of the first cutting body adjacent to the second cutting body has an assembly block, the second cutting body has a third slot body matched with the assembly block, and the assembly block and the third slot body are both provided with a first connecting hole and a first connecting member.

[0012] The assembly block of the first cutting body can be inserted and matched with the third slot body to complete the disassembly and assembly of the drill body, different lengths or numbers of the first cutting body can be selected for installation according to the use requirements, the use flexibility is improved, the first connecting member is used to ensure the close connection effect of the insertion, the first connecting member is a bolt or screw structure, and in the inserted and matched state of the assembly block and the third slot body, the impact stress can be uniformly dispersed on the insertion part when the drill bit is rotated and subjected to periodic impact force in cooperation with the motor during the working process of the electric hammer drill, the fatigue fracture caused by stress concentration is reduced, and the overall coaxiality of the assembly block and the third slot body in the inserted and matched state can be guaranteed, to avoid hole deflection.

[0013] According to an embodiment of the present application, the bottom of the assembly block is provided with a first elastic member with elasticity, and the groove bottom surface of the third groove body has a groove cavity accommodating the first elastic member of the bottom of the assembly block. The assembly block is connected to the third groove body in a plug-in manner, and the two groove surfaces of the third groove body are provided with inner recessed groove bodies, and the assembly block is provided with a protruding portion in plug-in cooperation with the inner recessed groove bodies.

[0014] The inner recessed groove bodies of the third groove body and the protruding portion of the assembly block can form a centering effect during plugging to ensure that coaxiality alignment is achieved simultaneously during plugging, so that the possibility of hole deflection during product use is reduced. During assembly, the inner recessed groove bodies of the third groove body have a guiding installation effect by cooperating with the protruding portion of the assembly block, which shortens the complexity of plugging installation and the time for plugging. The first elastic member provided therein is a structure with elastic function, such as a metal spring, an elastic column, etc. On one hand, it is used for centering and installation guiding during plugging installation, and on the other hand, it is used for absorbing impact stress transmission and consumption during product use.

[0015] According to an embodiment of the present application, the second cutting body is provided with a third cutting body at the connecting end of the first shank, the first shank is provided with a first mounting hole accommodating the third cutting body, and the second cutting body is provided with a threaded connecting section connected to the first shank. The first connecting hole is arranged on the second cutting body and the first shank respectively, and the first connecting member is arranged, so that the connection tightness of the second cutting body and the first shank is further reinforced through the first connecting member after the threaded connection of the second cutting body and the first shank, the axial and circumferential positions of the two are limited, the separation or loosening of the two during drilling is avoided, and the drilling precision is ensured. The first mounting hole is provided with a thread matched with the threaded connecting section, the existence of the third cutting body improves the application flexibility of the electric hammer drill, the diameter of the third cutting body is different from that of the second cutting body, which is smaller in size, and the number of carried drill bits is reduced. The coaxiality of the second cutting body and the first shank is realized by the threaded connection between the first shank and the second cutting body.

[0016] According to an embodiment of the present application, the second shank is detachably connected to the third groove body, the second shank is provided with an assembly block at the bottom, the assembly block on the second shank is provided with a threaded auxiliary connecting hole body corresponding to the first connecting hole on the third groove body, and a first connecting piece is arranged, the bottom of the assembly block on the second shank is provided with a first elastic piece with elasticity, the assembly block on the second shank is in plug-in connection with the third groove body, the two groove surfaces of the third groove body are provided with inner groove bodies, the assembly block on the second shank is provided with a protruding part in plug-in cooperation with the inner groove bodies, and when the third cutting body is used, the second shank and the third groove body are assembled to form an electric hammer drill with a smaller drilling size. The electric hammer drill can be flexibly adjusted and assembled. During drilling, a pre-drilling method is usually used, that is, a drill with a relatively small diameter is used for pre-drilling, and then a drill with a target size is used for drilling. In this way, the drilling accuracy can be ensured, the damage to the hole wall and the surrounding is reduced, and the debris discharge effect is better. The third cutting body of the present application can be used for pre-drilling operation without the need for additional configuration of other diameter drills.

[0017] According to an embodiment of the present application, the first mounting hole is built-in with a first spring, and the hole wall of the first mounting hole is provided with a protruding ring. The first spring is arranged at the bottom of the first mounting hole, and the protruding ring is arranged adjacent to the first spring. The first spring can be in contact with the end of the third cutting body, so as to center the third cutting body and protect the end of the third cutting body from shaking and contacting the hole wall of the first mounting hole. The presence of the protruding ring can guide the first spring and the third cutting body to be located at the central position of the first shank, and reduce the possibility of shaking of the first spring and the third cutting body. When the electric hammer drill is working, the stress transmitted to the third cutting body can be partially consumed by the first spring, which helps to ensure the stable connection and coaxiality of the first shank and the second cutting body.

[0018] According to an embodiment of the present application, the first shank is externally provided with a detachable first ring body, the first cutting body is externally provided with a second spring, and the second spring is connected with the first ring body through a second elastic element. One end of the second spring is connected with the second elastic element, and the other end is connected with a retaining ring. The retaining ring is in the form of a ring body and has a middle part capable of allowing displacement of the first cutting body. A connecting circular hole is formed in the retaining ring. The first ring body has a threaded connecting hole formed therein. A second connecting element is arranged in the threaded connecting hole. The second connecting element is screwed to abut against the outer wall of the first shank, so that the first ring body is connected with the first shank. The first ring body is arranged at the connecting position of the first shank and the second cutting body. The first ring body provides external connection and auxiliary limiting. The connection between the first shank and the second cutting body is further improved. The second spring is supported by the second elastic element. When the electric hammer drill is working, the second spring absorbs part of the vibration, reduces the impact on the arm, reduces the fatigue of the operator, and makes the contact between the drill bit and the workpiece more stable. The second spring ensures that the drill bit is always in contact with the drilling target, so that the instantaneous rigid impact between the drill bit and the drilling target is reduced. The drill bit and the drilling target are connected in a welded manner. The connecting circular hole in the retaining ring provides the connecting position of the second spring and the drill bit.

[0019] According to an embodiment of the present application, the second elastic element is arranged outside the first cutting body and has an opening allowing displacement of the first cutting body.

[0020] According to an embodiment of the present application, the end of the first cutting body is detachably connected with a third tool bit or a fourth tool bit. The second tool bit is a three-blade tool bit, the third tool bit is a four-blade tool bit, and the fourth tool bit is a two-blade tool bit. The cutting edge surface of the fourth tool bit has a fourth groove. The fourth groove and the cutting surface of the fourth tool bit have an inclination angle. In this way, the cutting and discharge of debris are smooth. The fourth groove is connected with the side surface of the fourth tool bit. The fourth groove can be applied to the second tool bit and the third tool bit.

[0021] According to an embodiment of the present application, the first shank is externally provided with a double-key groove or a single-key groove, so that the electric hammer drill of the present application can be adapted to various devices.

[0022] Compared with the prior art, the beneficial effects of the present application are that, compared with the prior art, the present application adopts a split assembly scheme, and the worn parts of the second cutter or the first cutting body and the second cutting body can be replaced separately, without scrapping the entire set of equipment, thereby reducing the use cost, and when facing different drilling targets, the assembly method, drill bit, etc. can be selected for replacement, so that flexible adjustment is realized, such as increasing the number of first cutting bodies to increase the overall electric hammer drill, without the need to provide various specifications and sizes of the overall electric hammer drill.

[0023] The electric hammer drill of the present application has a long service life and low cost, can flexibly adjust the assembly of the electric hammer drill to cope with different drilling conditions, has high drilling accuracy, and has the advantages of small damage to the surrounding of the drilled hole. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only exemplary, and other embodiments can be obtained by extending the provided drawings without creative labor for those skilled in the art.

[0025] Figure 1 A schematic diagram of the welding of the existing drill body and the first cutter;

[0026] Figure 2 A schematic diagram of an electric hammer drill scheme of the present application;

[0027] Figure 3 A schematic diagram of a first cutting body scheme of the present application;

[0028] Figure 4 A schematic diagram of a second cutting body and second cutter shank connection scheme of the present application;

[0029] Figure 5 A schematic diagram of the internal structure of the first cutter shank of the present application;

[0030] Figure 6 A second external structure form of the first cutter shank of the present application;

[0031] Figure 7 A third external structure form of the first cutter shank of the present application;

[0032] Figure 8 A schematic diagram of a first cutting body and third cutter connection scheme of the present application;

[0033] Figure 9 A schematic diagram of a first cutting body and fourth cutter connection scheme of the present application;

[0034] Figure 10This is a partially enlarged schematic diagram of the fourth cutting head of the present invention;

[0035] Figure 11 This is a schematic diagram of the connection scheme between the first cutting body and the second spring of the present invention.

[0036] Explanation of reference numerals in the attached drawings: 10. Drill body; 11. First cutting head; 20. Second cutting head; 21. Third cutting head; 22. Fourth cutting head; 23. Fourth groove; 30. First connecting member; 40. First cutting body; 41. First plane; 42. First groove; 43. Second groove; 44. First elastic element; 45. Assembly block; 46. First connecting hole; 50. Second cutting body; 51. First tool holder; 52. Third groove; 53. Threaded connection section; 54. Third cutting body; 55. Convex ring; 56. First spring; 57. First mounting hole; 60. Second tool holder; 70. First ring body; 71. Second connecting member; 72. Second elastic element; 73. Second spring; 74. Retaining ring. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] The concepts involved in this application will first be described with reference to the accompanying drawings. It should be noted that the following descriptions of various concepts are only for the purpose of making the content of this application easier to understand and do not constitute a limitation on the scope of protection of this application; furthermore, the embodiments and features in the embodiments of this application can be combined with each other unless otherwise specified. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0039] Example 1:

[0040] like Figures 1-5 As shown, the present invention provides an electric hammer drill, including a first cutting body 40, a second cutting head 20 connected to one end of the first cutting body 40, a second cutting body 50 detachably connected to the other end of the first cutting body 40, and a first tool holder 51 connected to the second cutting body 50. The first tool holder 51 is used for assembly with the electric drill clamping component.

[0041] Compared with the prior art of welding the first cutter head 11 on the drill body 10, the application adopts a split assembly scheme, and the worn parts of the second cutter head 20 or the first cutting body 40 and the second cutting body 50 can be replaced separately, without scrapping the entire set of equipment, thereby reducing the use cost. When facing different drilling targets, the assembly method and the drill bit can be replaced to achieve flexible adjustment, such as increasing the number of first cutting bodies 40 to increase the overall electric hammer drill, without the need to equip various specifications and sizes of the overall electric hammer drill, thereby reducing the cost. More importantly, the split assembly scheme can guarantee the coaxiality of the entire electric hammer drill, and compared with the prior art of welding the first cutter head 11 on the drill body 10, the application can solve the problems of inclined hole drilling and obvious damage to the surrounding of the hole caused by the decrease of the coaxiality.

[0042] The first cutting body 40 has a concave first groove body 42 at one end, the first groove body 42 penetrates through the two side surfaces of the first cutting body 40, the second cutter head 20 has a first mounting block matched with the first groove body 42, and the first mounting block and the first groove body 42 are respectively provided with corresponding first connecting holes 46 and are matched with first connecting pieces 30. The first groove body 42 of the first cutting body 40 can be inserted and matched with the first mounting block, which can realize quick disassembly and assembly when replacing the drill bit, especially in special application scenarios, which greatly shortens the drill bit replacement time. In addition, the insertion and matching mode avoids the wear and rust risk of the existing threaded connection, and the first connecting piece 30 ensures the tight connection effect of the insertion. The first connecting piece 30 is a bolt or screw structure. In addition, after the first groove body 42 and the first mounting block are inserted and matched, the impact stress can be uniformly dispersed on the insertion part under the condition that the drill bit is rotated and subjected to periodic impact force in cooperation with the motor during the working process of the electric hammer drill, thereby reducing the fatigue fracture caused by stress concentration. In addition, the overall coaxiality can be guaranteed after the first groove body 42 and the first mounting block are inserted and matched, thereby avoiding hole deflection.

[0043] The insertion and connection parts of the application are subjected to carburizing and quenching treatment to improve the strength and ensure that the structure can withstand torque and impact after insertion.

[0044] After the first groove body 42 and the first mounting block are inserted and matched, the first connecting piece 30 is screwed into the first connecting hole 46, which is a threaded hole, thereby realizing the tight connection of the first groove body 42 and the first mounting block. In this state, the connection gap between the second cutter head 20 or the first cutting body 40 and the second cutting body 50 is not easy to be blocked, such as in a mud or dust environment, the threaded connection mode is more likely to be blocked and stuck.

[0045] The slot side of the first slot body 42 has a second slot body 43, the slot bottom of the first slot body 42 has a mounting slot, the first mounting block has a protruding part filling the second slot body 43, the bottom of the first mounting block has a first elastic member 44 filling the mounting slot, the cooperating protruding part of the second slot body 43 can form a centering effect during splicing to ensure that coaxiality alignment is achieved simultaneously during splicing, so that the possibility of hole deflection during product use is reduced, and the second slot body 43 has a guiding installation effect through cooperation with the protruding part during assembly, which shortens the complexity of splicing installation and shortens the splicing time. The first elastic member 44 provided therein is a structure with elastic function, such as metal spring, elastic column, etc., which is used for centering and installation guiding during splicing installation, and on the other hand, it is used for absorbing impact stress transmission and consumption during product use. For example, the stress transmitted from the second tool head 20 to the first cutting body 40 can be partially transmitted to the first elastic member 44 for consumption, so as to avoid loosening or gap between the two.

[0046] The first cutting body 40 is a rotary body structure and the surface is provided with a spiral groove, the first cutting body 40 is provided with a first plane 41 parallel to its axis on the end face adjacent to the second tool head 20, and the first plane 41 is smoothly transitioned with the spiral groove. The way of setting the spiral groove on the first cutting body 40 ensures that the drillings can be discharged through the spiral groove during drilling, avoiding the accumulation of drillings to block the drilling hole or damage the structure around the drilling hole, etc. When cooling liquid is needed during drilling of individual materials, the cooling liquid can be guided through the spiral groove to enter and contact the second tool head 20 for cooling. The existence of the first plane 41 helps to discharge the drillings generated during drilling of the drill bit to the spiral groove part. More importantly, the first plane 41 provided in cooperation with the spiral groove reduces the contact area between the drilling hole wall to reduce the drilling friction resistance and improve the drilling efficiency. During the discharge of the drillings from the drill bit to the spiral groove, the discharge path changes after passing through the first plane 41, which helps to break the chips and avoid the occurrence of overlong chip winding.

[0047] The end of the first cutting body 40 adjacent to the second cutting body 50 has an assembly block 45, the second cutting body 50 has a third slot body 52 matched with the assembly block 45, and the assembly block 45 and the third slot body 52 are both provided with a first connecting hole 46 and matched with a first connecting member 30.

[0048] The assembly block 45 of the first cutting body 40 of the present application can be inserted into the third groove body 52, and the drill body can be disassembled. Different lengths or numbers of first cutting bodies 40 can be selected according to the use requirements, and the use flexibility is improved. The first connecting piece 30 is used to ensure the close connection of the insertion. The first connecting piece 30 is a bolt or screw structure. When the assembly block 45 is inserted into the third groove body 52, the drill bit formed by the electric hammer drill and the motor can be rotated and subjected to periodic impact force during the working process. The impact stress can be uniformly dispersed at the insertion position, and the fatigue fracture caused by stress concentration can be reduced. The overall coaxiality of the assembly block 45 and the third groove body 52 in the inserted state can be ensured, and the hole deviation can be avoided.

[0049] The bottom of the assembly block 45 is provided with a first elastic member 44 having elasticity, and the groove bottom surface of the third groove body 52 has a groove cavity accommodating the first elastic member 44 at the bottom of the assembly block 45. The assembly block 45 is inserted into the third groove body 52, and the two groove surfaces of the third groove body 52 have inner recessed groove bodies. The assembly block 45 has a protruding portion inserted into the inner recessed groove body.

[0050] The inner recessed groove body of the third groove body 52 and the protruding portion of the assembly block 45 can form a centering effect during insertion to ensure that the coaxiality is aligned during insertion. Thus, the possibility of hole deviation during product use is reduced. The inner recessed groove body of the third groove body 52 has a guiding installation effect by cooperating with the protruding portion of the assembly block 45 during the assembly process, which shortens the complexity of insertion and installation and shortens the insertion time. The first elastic member 44 provided therein has a structure with elastic function, such as a metal spring, an elastic column, etc. On the one hand, it is used for centering and installation guiding during insertion. On the other hand, it is used for absorbing impact stress transmission and consumption during product use.

[0051] The second cutting body 50 has a third cutting body 54 connected to the connecting end of the first shank 51. The first shank 51 has a first mounting hole 57 accommodating the third cutting body 54. The second cutting body 50 is provided with a threaded connection section 53 connected to the first shank 51. The first connecting hole 46 is provided on the second cutting body 50 and the first shank 51, and the first connecting piece 30 is arranged. After the second cutting body 50 and the first shank 51 are connected by threads, the first connecting piece 30 is used to further reinforce the connection tightness of the two, and the axial and circumferential positions of the two are limited to avoid separation or loosening of the two during drilling to ensure drilling accuracy. The first mounting hole 57 is provided with threads matched with the threaded connection section. The presence of the third cutting body 54 improves the application flexibility of the electric hammer drill. The diameter of the third cutting body 54 is smaller than that of the second cutting body 50, which reduces the number of drill bits carried. The first shank 51 and the second cutting body 50 are connected by threads to realize the coaxiality of the second cutting body 50 and the first shank 51.

[0052] The second shank 60 is detachably connected to the third slot body 52, the bottom of the second shank 60 is provided with an assembly block 45, the assembly block 45 on the second shank 60 is provided with a threaded auxiliary connecting hole body corresponding to the first connecting hole 46 on the third slot body 52, and the first connecting piece 30 is arranged, the bottom of the assembly block 45 on the second shank 60 is provided with a first elastic piece 44 with elasticity, the assembly block 45 on the second shank 60 is in plug-in connection with the third slot body 52, the two slot surfaces of the third slot body 52 are provided with inner groove bodies, the assembly block 45 on the second shank 60 is provided with a protruding part in plug-in cooperation with the inner groove bodies, when the third cutting body 54 is used, the second shank 60 and the third slot body 52 are assembled to form an electric hammer drill with a smaller drilling size, the electric hammer drill is flexibly adjusted and assembled, and during drilling, a pre-drilling method is usually used, that is, a drill bit with a relatively small diameter is used for pre-drilling, and then a drill bit with a target size is used for drilling, so that the drilling accuracy can be ensured, the damage to the hole wall and the periphery is reduced, and the debris discharge effect is better, and the third cutting body 54 of the electric hammer drill can be used for pre-drilling operation without the need for additional configuration of other diameter drill bits.

[0053] The first spring 56 is arranged in the first mounting hole 57, and the convex ring 55 is arranged on the hole wall of the first mounting hole 57. The first spring 56 is arranged at the bottom of the first mounting hole 57, and the convex ring 55 is arranged adjacent to the first spring 56. The first spring 56 can be in contact with the end of the third cutting body 54, so as to center the third cutting body 54 and protect the end of the third cutting body 54, avoiding the end of the third cutting body 54 from shaking and contacting the hole wall of the first mounting hole 57. The existence of the convex ring 55 can guide the first spring 56 and the third cutting body 54 to be located at the central position of the first shank 51, and reduce the possibility of shaking of the first spring 56 and the third cutting body 54. When the electric hammer drill is working, the stress transmitted to the third cutting body 54 can be partially consumed by the first spring 56, which helps to ensure the stability of the connection between the first shank 51 and the second cutting body 50 and the coaxiality.

[0054] Embodiment 2:

[0055] Referring to the drawings Figure 6 - the drawings Figure 7 As shown in the drawings, the embodiment is further provided on the basis of the embodiment 1, that is, the first shank 51 is provided with a double-headed key groove or a single-headed key groove, so that the electric hammer drill of the embodiment can be adapted to various devices.

[0056] Embodiment 3:

[0057] Referring to the drawings Figure 8 - the drawings Figure 10As shown, the embodiment is further based on the embodiment 1, and the first cutting body 40 can be detachably connected with the third cutter head 21 or the fourth cutter head 22, the second cutter head 20 is a three-blade cutter head, the third cutter head 21 is a four-blade cutter head, the fourth cutter head 22 is a two-blade cutter head, the fourth cutter head 22 has a fourth groove body 23, the fourth groove body 23 has an inclined angle with the cutting surface of the fourth cutter head 22, so that the cutting and discharge of the debris are smooth, and the fourth groove body 23 can communicate with the side surface of the fourth cutter head 22. The fourth groove body 23 can be applied to the second cutter head 20 and the third cutter head 21.

[0058] Embodiment 4:

[0059] Referring to the drawings Figure 11 As shown, the embodiment is further based on the embodiment 1, and the first cutter handle 51 is externally provided with a detachable first ring body 70, the first cutting body 40 is externally provided with a second spring 73, and the second spring 73 is connected with the first ring body 70 through a second elastic member 72. One end of the second spring 73 is connected with the second elastic member 72, and the other end is connected with a stop ring 74. The stop ring 74 is a ring body structure and can allow displacement of the first cutting body 40 in the middle part. A connecting circular hole is formed in the stop ring 74. The first ring body 70 has a threaded connecting hole, and a second connecting member 71 is arranged in the threaded connecting hole. By screwing the second connecting member 71, the second connecting member 71 abuts against the outer wall of the first cutter handle 51, so that the first ring body 70 and the first cutter handle 51 form a connecting relationship. The first ring body 70 can be arranged at the connecting position of the first cutter handle 51 and the second cutting body 50 to provide external connecting auxiliary limiting, so that the connection between the first cutter handle 51 and the second cutting body 50 is further improved. The existence of the first ring body 70 can cooperate with the second elastic member 72 to provide support for the second spring 73. During the operation of the electric hammer drill, the second spring 73 can absorb part of the vibration to reduce the impact on the arm and reduce the fatigue of the operator. The buffering effect of the second spring 73 cooperating with the second elastic member 72 can also make the contact between the drill bit and the workpiece more stable, so as to avoid slipping or deviation caused by violent vibration. More importantly, during the continuous impact process, the second spring 73 can ensure that the drill bit always adheres to the drilling target, so as to relieve the instantaneous rigid impact between the drill bit and the drilling target. This also relatively reduces the drilling noise. The existence of the stop ring 74 helps to ensure the stable abutment of the second spring 73 and the drilling target. The stop ring 74 and the second spring 73 are connected in a welding manner. The connecting circular hole in the stop ring 74 provides the connecting position of the two.

[0060] The second elastic member 72 is sleeved on the first cutting body 40 and has an opening allowing displacement of the first cutting body 40.

[0061] It should be noted that the terms used in the present application are only intended to describe specific embodiments and are not intended to limit the scope of the present application. As shown in the specification of the present application, unless the context clearly indicates otherwise, "one", "a", "an", and / or "the" do not refer to the singular, but also include the plural. The terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method or device. Without more limitations, the element defined by the statement "including a" does not exclude the presence of additional identical elements in the process, method or device including the element.

[0062] It should also be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only intended to facilitate the description of the present application and simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. Unless otherwise specifically defined and limited, the terms "mount", "connect", "connect" and the like should be broadly understood, for example, it can be a fixed connection, or it can be a detachable connection, or it can be integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the communication between two elements inside. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0063] The above embodiments and / or implementations are only used to illustrate the preferred embodiments and / or implementations of the present application, and do not limit the implementation of the present application in any form. Any person skilled in the art can make some changes or modifications to other equivalent embodiments without departing from the scope of the technical means disclosed in the present application, but should be considered as substantially the same technology or embodiment as the present application.

[0064] The principles and implementations of the present application are described herein using specific examples. The above description of the embodiments is only used to help understand the method and core idea of the present application. The above description is only the preferred embodiment of the present application. It should be noted that due to the limited nature of the language, there are objectively infinite specific structures. For those skilled in the art, without departing from the principles of the present application, some improvements, refinements or changes can be made, or the above technical features can be combined in an appropriate manner; these improvements, refinements, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should be considered as the protection scope of the present application.

Claims

1. An electric hammer drill comprising a first cutting body (40) connected at one end with a second tool bit (20), characterized in that, The first cutting body (40) is detachably connected with a second cutting body (50) at the other end, and the second cutting body (50) is connected with a first shank (51). The first cutting body (40) has a concave first groove body (42) at one end, the first groove body (42) penetrates through both side faces of the first cutting body (40), the second tool bit (20) has a first mounting block at the bottom, which cooperates with the first groove body (42), and the first mounting block and the first groove body (42) are respectively provided with corresponding first connecting holes (46) and are provided with a first connecting piece (30). The groove side face of the first groove body (42) has a second groove body (43), the groove bottom face of the first groove body (42) has a mounting groove, the first mounting block has a protruding part filling the second groove body (43), and the bottom of the first mounting block has a first elastic piece (44) filling the mounting groove. The first cutting body (40) is a rotary body structure and has a spiral groove around the surface, and the first cutting body (40) is provided with a first plane (41) parallel to the axis on the end face of the adjacent second tool bit (20), The first shank (51) is externally provided with a detachable first ring body (70), the first cutting body (40) is externally sleeved with a second spring (73), and the second spring (73) is connected with the first ring body (70) through a second elastic piece (72); one end of the second spring (73) is connected with the second elastic piece (72), and the other end is connected with a stop ring (74), the stop ring (74) is a ring body structure and can allow displacement of the first cutting body (40) at the middle part, and the stop ring (74) is provided with a connecting circular hole; The first ring body (70) has a threaded connecting hole, the threaded connecting hole is provided with a second connecting piece (71), and the second connecting piece (71) is abutted against the outer wall of the first shank (51) by screwing; The end of the first cutting body (40) adjacent to the second cutting body (50) has an assembly block (45), and the bottom of the assembly block (45) is provided with a first elastic piece (44) with elasticity.

2. The hammer drill according to claim 1, wherein The second cutting body (50) has a third groove body (52) matched with the assembly block (45), and the assembly block (45) and the third groove body (52) are both provided with first connecting holes (46) and are provided with a first connecting piece (30).

3. The hammer drill of claim 2, wherein, The groove bottom face of the third groove body (52) has a groove cavity accommodating the first elastic piece (44) at the bottom of the assembly block (45).

4. The hammer drill of claim 1, wherein, The connecting end of the second cutting body (50) and the first shank (51) has a third cutting body (54), the first shank (51) has a first mounting hole (57) accommodating the third cutting body (54), and the second cutting body (50) is provided with a threaded connecting section (53) connected with the first shank (51).

5. The hammer drill of claim 4 wherein, The first mounting hole (57) is internally provided with a first spring (56), and the hole wall of the first mounting hole (57) is provided with a convex ring (55).

6. The hammer drill of claim 1, wherein, The second elastic piece (72) is sleeved outside the first cutting body (40) and has an opening allowing movement of the first cutting body (40).

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