Electric hammer structure

Abstract

The utility model discloses an electric hammer structure which comprises a machine shell, an air cylinder assembly, a driving assembly and a switching knob, the air cylinder assembly comprises an air cylinder and a cylinder sleeve arranged at one end of the air cylinder in a sleeved mode, an annular connecting part is formed on the cylinder sleeve, and a switching ring is arranged in the connecting part; the driving assembly comprises a driving gear and a striking mechanism, the driving gear can be meshed with insections on the cylinder sleeve to drive the cylinder sleeve and the air cylinder to rotate, the striking mechanism comprises a striking block and a transmission shaft assembly arranged at the rear end of the air cylinder, and the transmission shaft assembly is connected with the striking block and drives the striking block to reciprocate in the air cylinder; the switching knob is arranged on the machine shell and connected to the switching ring, and the switching knob can rotate to drive the switching ring and the cylinder sleeve to move in the axial direction, so that the insection is meshed with or away from the driving gear. According to the electric hammer structure, the cylinder sleeve and the driving gear are directly disconnected, so that the function switching of the electric hammer is realized, the structure is simple, and the stability is high.

Description

Technical Field

[0001] The utility model belongs to the technical field of electric tools, and particularly relates to a structure of a hammer drill. Background Art

[0002] A hammer drill is a tool that can drill and chisel simultaneously. While drilling, it chisels, so as to drill holes in relatively hard objects such as concrete. In the prior art, a hammer drill can switch between the two functions of hammer drilling and chiseling. Currently, in the prior art, most hammer drills use the meshing and disengagement between different transmission shafts to switch different functions, with a relatively complex structure and a large amount of heat generated during operation.

[0003] The information disclosed in this background art section is only intended to enhance the overall understanding of the present utility model and should not be regarded as an admission or any form of implication that this information constitutes the prior art already known to those of ordinary skill in the art. Summary of the Utility Model

[0004] The purpose of the present utility model is to provide a hammer drill structure with higher stability.

[0005] To achieve the above purpose, a specific embodiment of the present utility model provides a hammer drill structure, including a housing, a cylinder assembly, a driving assembly, and a switching knob. The cylinder assembly is arranged inside the housing and includes a cylinder and a cylinder sleeve. The cylinder sleeve is sleeved at one end of the cylinder, and the cylinder sleeve can axially move relative to the cylinder and can rotate together with the cylinder. An annular connecting portion is formed on the cylinder sleeve. The hammer drill structure further includes a switching ring sleeved on the connecting portion. Tooth patterns are arranged on an outer wall of one side of the cylinder sleeve. The driving assembly is arranged inside the housing and includes a driving gear and a striking mechanism. The driving gear can mesh with the tooth patterns to drive the cylinder sleeve and the cylinder to rotate. The striking mechanism includes a striking block arranged inside the cylinder and a transmission shaft assembly arranged at the rear end of the cylinder. The transmission shaft assembly is connected to and drives the striking block to reciprocate inside the cylinder. The switching knob is arranged on the housing and is connected to the cylinder sleeve. Wherein the switching knob is operated to rotate clockwise or counterclockwise to drive the switching ring to axially move, so that the tooth patterns mesh with or move away from the driving gear.

[0006] In one or more embodiments of the present utility model, the cylinder sleeve is further provided with an annular card slot. The cylinder assembly further includes a snap ring clamped on the annular card slot. The end face of the tooth patterns close to the switching ring and the snap ring limit the axial movement of the switching ring. A gasket is arranged at each of the two axial ends of the switching ring.

[0007] In one or more embodiments of the present utility model, a torsion spring is wound around the switching ring, and the switching knob includes a positioning post that extends and is inserted between two arms of the torsion spring.

[0008] In one or more embodiments of the present utility model, a plurality of arc-shaped bumps are provided on the switching ring, the bumps are evenly distributed on the inner wall of the switching ring, and the apex of the bump contacts the bottom wall of the connecting portion.

[0009] In one or more embodiments of the present utility model, a plurality of first key grooves are formed on the outer wall of the cylinder, a plurality of first keys protruding from the inner wall of the cylinder sleeve are embedded in the first key grooves, and the rotation of the switching knob causes the first keys to axially slide in the first key grooves.

[0010] In one or more embodiments of the present utility model, a plurality of second keys are provided on the outer wall of the cylinder sleeve, a plurality of second key grooves for accommodating the second keys are provided on the inner wall of the machine housing, the number of the second key grooves is the same as that of the second keys, and the switching knob can drive the cylinder sleeve to move so that the second keys enter or disengage from the second key grooves.

[0011] In one or more embodiments of the present utility model, the first key grooves are evenly distributed on the outer wall of the cylinder, and / or the second keys are evenly distributed on the outer wall of the cylinder sleeve.

[0012] In one or more embodiments of the present utility model, the cylinder is provided with a retaining wall, and a spring is compressed between the retaining wall and the cylinder sleeve.

[0013] In one or more embodiments of the present utility model, the second key is formed at the edge of the cylinder sleeve, and the spring is compressed between the retaining wall and the second key.

[0014] In one or more embodiments of the present utility model, a plurality of limiting plates surrounding the cylinder are arranged in the machine housing, the second key grooves are formed between adjacent limiting plates, and the spring is limited by the limiting plates.

[0015] Compared with the prior art, the present utility model realizes the switching of the electric hammer function by directly disconnecting the connection between the cylinder sleeve and the driving gear, with a simple structure and high stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 Schematic diagram of the structure of a hammer drill in an embodiment of the present utility model;

[0018] Figure 2 Partial disassembly diagram of the structure of a hammer drill in an embodiment of the present utility model;

[0019] Figure 3 Schematic diagram of a cylinder in an embodiment of the present utility model;

[0020] Figure 4 Combined schematic diagram of a cylinder, a circlip and a gasket in an embodiment of the present utility model;

[0021] Figure 5 Schematic diagram of a cylinder liner in an embodiment of the present utility model;

[0022] Figure 6 Schematic diagram of a switching ring in an embodiment of the present utility model;

[0023] Figure 7 Schematic diagram of a striking mechanism in an embodiment of the present utility model;

[0024] Figure 8 Cross-sectional view of the structure of a hammer drill in an embodiment of the present utility model.

[0025] Description of main reference numerals:

[0026] 10 - housing, 11 - second keyway, 12 - limit plate, 20 - cylinder, 21 - first keyway, 22 - retaining wall, 30 - cylinder liner, 31 - connecting portion, 32 - first key, 33 - second key, 34 - gasket, 35 - annular card slot, 36 - circlip, 37 - tooth pattern, 40 - switching ring, 41 - convex block, 42 - torsion spring, 50 - drive gear, 60 - striking mechanism, 61 - eccentric wheel, 62 - transmission shaft, 63 - first striking block, 64 - second striking block, 70 - switching knob, 71 - positioning post, 80 - spring. Detailed implementation manners

[0027] In order to enable those skilled in the art to better understand the technical solutions in the present utility model, the following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts shall fall within the protection scope of the present utility model.

[0028] As Figure 1-8 shown, the structure of a hammer drill in an embodiment of the present utility model includes a housing 10( Figure 1Only a part of the housing at the front end of the electric hammer, the cylinder assembly, the drive assembly, and the switching knob 70 are shown. The cylinder assembly is disposed within the housing 10 and includes a cylinder 20 and a cylinder liner 30. One end of the cylinder 20 is used to connect tools such as drill bits and flat drills. The power output of the electric hammer is transmitted to the other end of the cylinder 20 to drive the cylinder 20 to rotate and perform a striking operation through the drive assembly. The cylinder liner 30 is sleeved on one end of the cylinder 20 and can axially move relative to the cylinder 20 and rotate together with the cylinder 20. An annular connecting portion 31 is formed on the cylinder liner 30, and a switching ring 40 is disposed within the connecting portion 31. The switching ring 40 can rotate within the connecting portion 31, and a tooth pattern 37 is formed on one side of the cylinder liner 30. The drive assembly includes a drive gear 50 and a striking mechanism 60. The drive gear 50 meshes with the tooth pattern 37 on the cylinder liner 30 and is connected to the power source of the electric hammer (not shown in the figure) to drive the cylinder liner 30 and the cylinder 20 to rotate. The striking mechanism 60 includes a striking block disposed within the cylinder 20 and a transmission shaft assembly connected to the striking block. The transmission shaft assembly can drive the striking block to reciprocate within the cylinder 20 to form a striking operation. The switching knob 70 is disposed on the housing 10. When it rotates clockwise or counterclockwise, it can drive the switching ring 40 and the cylinder liner 30 to axially move, so that the cylinder liner 30 approaches the drive gear 50 and meshes with it, or drives the cylinder liner 30 away from the drive gear 50 and disengages from it. When the cylinder liner 30 and the drive gear 50 are meshed, the striking mechanism 60 strikes while the cylinder 20 rotates, and the electric hammer enters the hammer-drill function; when the two are disengaged, the cylinder 20 does not rotate when the striking mechanism 60 performs a striking operation, and the electric hammer enters the chiseling function.

[0029] Compared with the common method of realizing function switching by designing the transmission shaft (the cylinder liner 20 and the drive gear 50 are always meshed, and the power transmission between the power source and the drive gear 50 is cut off), when the electric hammer in this embodiment switches to the chiseling function, the connection between the cylinder liner 30 and the drive gear 50 is directly disconnected. Therefore, the transmission design connected to the drive gear 50, the transmission shaft assembly, and the power source is simplified, the structure is relatively simple, and the stability is higher.

[0030] In one embodiment, an annular card slot 35 is further provided on the cylinder liner 30, and a snap ring 36 is clamped within the annular card slot 35. The switching ring 40 is limited between the snap ring 36 and the end face of the tooth pattern 37 close to the switching ring 40, so that the switching ring 40 can rotate relative to the cylinder liner 30 but cannot axially move relative to each other. And smooth gaskets 34 are respectively disposed at both axial ends of the switching ring 40 and are respectively pressed between the switching ring 40 and the end faces of the snap ring 36 and the tooth pattern 37 to reduce friction.

[0031] Specifically, a plurality of first keyways 21 are provided on the outer wall of the cylinder 20. Correspondingly, a plurality of first keys 32 protruding from the inner wall of the cylinder liner 30 and inserted into the first keyways 21 are provided. The numbers of both can be the same and correspond one by one. Since the extending direction of the first keyway 21 is the axial direction of the cylinder 20, the cylinder 20 and the cylinder liner 30 can only generate relative displacement in the axial direction. When the cylinder liner 30 rotates, since the first key 32 is stuck in the first keyway 21, the cylinder 20 can be driven to rotate together.

[0032] It should be understood that since the cylinder liner 30 moves in the axial direction of the cylinder 20 when switching functions, in order to ensure continuous engagement, the first key 32 is always located in the first keyway 21 within the moving range of the cylinder liner 30.

[0033] Preferably, the first keyways 21 are evenly distributed on the outer wall of the cylinder 20. Correspondingly, the first keys 32 are evenly distributed on the inner wall of the cylinder liner 30 to receive uniform force.

[0034] Since the cylinder liner 30 needs to move forward to disengage from the drive gear 50 when in the chiseling function, in order to ensure that the cylinder 20 does not rotate during chiseling, it is necessary to fix the cylinder liner 30. In one embodiment, a plurality of second keys 33 are provided on the outer wall of the cylinder liner 30. Correspondingly, a plurality of second keyways 11 are provided on the inner wall of the housing 10, and the numbers of them are the same. When the switching knob 70 rotates and drives the cylinder liner 30 to move forward, the second keys 33 enter the second keyways 11, thereby fixing the cylinder liner 30 and the cylinder 20 to the housing 10, enabling the electric hammer to perform chiseling operations.

[0035] Preferably, the second keys 33 are also evenly distributed on the outer wall of the cylinder liner 30. Similarly, the second keyways 11 are evenly distributed inside the housing 10 to receive uniform force.

[0036] As Figure 6 shown, a torsion spring 42 is wound around the switching ring 40. The switching knob 70 includes a positioning post 71 extending and abutting against the torsion spring 42, and the positioning post 71 can be inserted into the space surrounded by the torsion spring 42. Preferably, it protrudes from the edge position of the switching knob 70. Therefore, when the switching knob 70 rotates, the rotation amplitude of the positioning post 71 is relatively large, and the switching ring 40 and the cylinder liner 30 are driven to move by squeezing the torsion spring 42 on both sides.

[0037] Since the switching ring 40 is always stationary relative to the housing 10, and the cylinder liner 30 rotates together with the cylinder 20 for a long time, the switching ring 40 and the cylinder liner 30 are usually in a rotating state during operation. To reduce friction, a plurality of arc-shaped protrusions 41 protrude from the inner wall of the switching ring 40, and the protrusions 41 directly contact the bottom of the connecting portion 31, so the friction is small.

[0038] As Figure 3As shown, a stop wall 22 is provided at a position near the front end of the cylinder 20, and a spring 80 is compressed between the stop wall 22 and the cylinder liner 30. Since the working environment of the electric hammer is relatively poor and large vibrations will be generated during operation, a spring 80 is provided between the cylinder 20 and the cylinder liner 30 to provide buffering and reduce the impact caused by vibrations.

[0039] Preferably, to prevent the spring 80 from deforming radially along itself and slipping onto the cylinder liner 30, the second key 33 is arranged at the edge position on the side near the front end. Therefore, the height at which the spring 80 is blocked by the cylinder liner 30 is the thickness of the main body part of the cylinder liner 30 and the height of the second key 33, which can prevent the spring 80 from detaching from the end of the cylinder liner 30 and has higher stability.

[0040] To further improve the stability of the spring 80, a plurality of limiting plates 12 protrude from the inner wall of the housing 10. They surround the outside of the cylinder 20 to form a cylindrical area. The second keyway 11 is formed between two adjacent limiting plates 12. At the same time, the spring 80 is located within the cylindrical area and is limited between all the limiting plates 12, avoiding the situation of deforming radially and improving the stability.

[0041] As Figure 7 shown, the transmission shaft assembly includes an eccentric wheel 61 at the top and a transmission shaft 62 connected to the eccentric wheel. The striking mechanism 60 further includes a first striking block 63 and a second striking block 64, which are arranged one in front of the other inside the cylinder 20. The former is used to abut against tools such as drill bits and flat drills. The transmission shaft 62 makes a reciprocating motion inside the cylinder 20 under the drive of the eccentric wheel 61, and it periodically acts on the second striking block 64, causing the second striking block 64 to periodically strike the first striking block 63, thereby forming a striking effect.

[0042] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be encompassed by the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0043] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An electric hammer structure, characterized in that: include: Housing (10); A cylinder assembly is arranged in the housing (10), comprising a cylinder (20) and a cylinder sleeve (30), wherein the cylinder sleeve (30) is sleeved on one end of the cylinder (20), the cylinder sleeve (30) can move axially relative to the cylinder (20) and can rotate together with the cylinder (20), an annular connecting portion (31) is formed on the cylinder sleeve (30), and the electric hammer structure further comprises a switching ring (40) sleeved on the connecting portion (31), and a tooth pattern (37) is provided on one side outer wall of the cylinder sleeve (30); a driving assembly, arranged in the housing (10), comprising a driving gear (50) and a striking mechanism (60), wherein the driving gear (50) is capable of meshing with the tooth pattern to drive the cylinder sleeve (30) and the cylinder (20) to rotate, and the striking mechanism (60) comprises a striking block arranged in the cylinder (20), and a transmission shaft assembly arranged at the rear end of the cylinder (20), wherein the transmission shaft assembly is connected to and drives the striking block to reciprocate in the cylinder (20); as well as A switching knob (70) is arranged on the housing (10) and connected to the switching ring (40); the switching knob (70) is operated to rotate clockwise or counterclockwise to drive the switching ring (40) to move axially, so that the tooth pattern engages with or moves away from the driving gear (50).

2. The electric hammer structure according to claim 1, characterized in that: The cylinder sleeve (30) is also provided with an annular groove (35), and the cylinder assembly also includes a retaining spring (36) that is clamped on the annular groove (35). The tooth pattern (37) is close to the end surface of the switching ring (40) and the retaining spring to limit the axial movement of the switching ring (40), and a gasket (34) is respectively provided at two axial ends of the switching ring (40).

3. The electric hammer structure according to claim 1, characterized in that: A torsion spring (42) is wound around the switching ring (40), and the switching knob (70) comprises a positioning column (71) extending and inserted between two arms of the torsion spring (42).

4. The electric hammer structure according to claim 1, characterized in that: The switching ring (40) is provided with a plurality of arc-shaped protrusions (41), the protrusions (41) are evenly distributed on the inner wall of the switching ring (40), and the vertices of the protrusions (41) are in contact with the bottom wall of the connecting portion (31).

5. The electric hammer structure according to claim 1, characterized in that: A plurality of first key grooves (21) are formed on the outer wall of the cylinder (20), a plurality of first keys (32) are protruding from the inner wall of the cylinder sleeve (30) and are embedded in the first key grooves (21), and the rotation of the switching knob (70) causes the first keys (32) to slide axially in the first key grooves (21).

6. The electric hammer structure according to claim 5, characterized in that: A plurality of second keys (33) are arranged on the outer wall of the cylinder sleeve (30), and a plurality of second key slots (11) for accommodating the second keys (33) are arranged on the inner wall of the housing (10), the number of the second key slots (11) and the number of the second keys (33) being the same, and the switching knob (70) can drive the cylinder sleeve (30) to move so that the second keys (33) enter or leave the second key slots (11).

7. The electric hammer structure according to claim 6, characterized in that: The first key grooves (21) are evenly distributed on the outer wall of the cylinder (20), and / or The second keys (33) are evenly distributed on the outer wall of the cylinder sleeve (30).

8. The electric hammer structure according to claim 6, characterized in that: The cylinder (20) is provided with a baffle wall (22), and a spring (80) is compressed between the baffle wall (22) and the cylinder sleeve (30).

9. The electric hammer structure according to claim 8, characterized in that: The second key (33) is formed on the edge of the cylinder sleeve (30), and the spring (80) is pressed between the retaining wall (22) and the second key (33).

10. The electric hammer structure according to claim 9, characterized in that: A plurality of limit plates (12) are arranged in the housing (10) and surround the outside of the cylinder (20); the second key groove (11) is formed between adjacent limit plates (12); and the spring (80) is limited by the limit plates (12).

Images