A stable crown jewel

Abstract

The utility model provides a kind of stable installation crown drill belongs to drill bit technical field.The utility model is arranged by the hole wall of the side of the slot bottom of the installation slot on drill rod is inclined conical surface by the limiting perforation on drill bit, the aperture of limiting perforation one end is enlarged, and the middle part of screw is arranged conically and the small head end is connected with threaded end, when screw is worn into limiting perforation, with the threaded end of smaller cross section is worn into from the larger one end of limiting perforation orifice, it is convenient for screw to pass through limiting perforation, avoid the end of screw to be limited by the orifice of perforation and the problem of being stopped, the dismounting of screw is facilitated, to facilitate the replacement of drill bit, and it can be pushed and squeezed the conical surface of limiting perforation by the outside wall of the middle part of screw conical after screw is twisted, drill bit is pushed and squeezed towards the slot bottom side of installation slot, so that drill bit can be more fitted installation slot, the stability after installation of drill bit is improved.

Description

Technical Field

[0001] This utility model relates to the field of drill bit technology, specifically to a crown drill that is stable to install. Background Technology

[0002] With the development of machining technology, various types of drilling drills have been introduced for hole machining, such as the crown drill which is widely used in the market. Its modular structure and higher machining accuracy have won the favor of consumers.

[0003] Currently, the existing crown drills on the market include drill rods and drill bits. The drill bits are disassembled and installed on the drill rods, so that the drill bits can be directly replaced if they are damaged. This modular design reduces the cost of use. For example, patent CN222660238U discloses a side-fixed crown drill, which includes a shank and a handle. A drill tip is provided on the shank, and a mounting groove is provided on the shank for mounting the drill tip. The drill tip is detachably fixed to the mounting groove by screws. Screw holes for screw installation are provided on both the front and rear sides of the mounting groove, and screw through holes for screw installation are provided on the drill tip. The center of the screw hole on the shank and the center of the screw through hole on the drill tip are eccentrically arranged, so that when the drill tip is installed on the shank, the drill tip is first inserted into the mounting groove, and then a screw passes through the screw through hole on the drill tip and connects to the screw holes on both sides of the mounting groove, thereby confining the drill tip in the mounting groove. Furthermore, since the center of the screw hole on the shank and the center of the screw through hole on the drill tip are eccentrically arranged, the drill tip can be pressed tightly into the mounting groove. Although the above structure can meet the installation requirements of the drill tip in the mounting slot on the tool holder, the center of the screw hole on the tool holder and the center of the screw through hole on the drill tip are eccentric. This causes the screw to be easily blocked by the wall of the eccentric screw through hole on the drill tip when it is inserted from the screw hole on one side of the mounting slot into the screw through hole on the drill tip. This makes installation inconvenient and affects the replacement of the drill bit. Summary of the Invention

[0004] To address the aforementioned problems in the existing technology, the aim is to provide a crown drill with stable installation. The screw has a conical center, and the limiting hole on the drill bit has a conical surface on the side near the mounting groove. The screw is inserted into the limiting hole from the end with the larger cross-section and connects to the threaded hole in the mounting groove. By continuing to tighten the screw, the center of the screw gradually presses against the limiting hole on the side near the mounting groove, thus pressing the drill bit firmly into the limiting groove. Furthermore, due to the larger cross-section, the screw end is not blocked when it enters the limiting hole, facilitating screw installation and drill bit replacement.

[0005] The specific technical solution is as follows: A crown drill with stable installation includes a drill rod, a drill bit, and a screw. One end of the drill rod has a recessed mounting groove along its axial direction. The drill bit has a transversely penetrating limiting hole. The drill rod has coaxially arranged screw holes and threaded holes on both sides of the mounting groove. During installation, the screw passes through the screw hole and through the limiting hole on the drill bit, and finally connects and locks with the threaded hole. It has the following features: the side of the limiting hole of the drill bit near the bottom of the groove is an inclined conical surface arranged along the axial direction of the limiting hole. At the same time, the screw has a variable cross-section structure, with one end being the threaded end and the middle part of the screw being conical. The small end of the middle part of the screw is connected to the threaded end and has the same cross-section.

[0006] The aforementioned crown drill with stable installation has a first positioning surface and a second positioning surface on both sides of the drill bit, and a first mating surface and a second mating surface on both sides of the mounting groove, respectively. The top of the drill bit is provided with a cutting edge, and the bottom of the drill bit is provided with a third positioning surface. The bottom wall of the mounting groove is a third mating surface, and the third positioning surface and the third mating surface are fitted together.

[0007] In the aforementioned type of crown drill with stable installation, the bottom of the drill bit is provided with an extended insert rod, and the bottom wall of the mounting groove is provided with an insertion hole corresponding to the insert rod.

[0008] In the aforementioned type of stable crown drill, the screw hole is a countersunk hole, and the countersunk end of the screw hole is located on the outer wall of the drill rod.

[0009] In the aforementioned crown drill with stable installation, deformation grooves are symmetrically formed on the drill rod on both sides of the insertion hole. The deformation grooves penetrate the side wall of the insertion hole, and the line connecting the deformation grooves on both sides of the insertion hole is perpendicular to the axial direction of the screw hole.

[0010] In the aforementioned crown drill with stable installation, an adjustment hole is provided radially on the outer side wall of the drill rod. One end of the adjustment hole is connected to the insertion hole. At the same time, a push screw is provided in the adjustment hole, and one end of the push screw extends into the insertion hole.

[0011] In the aforementioned type of crown drill with stable installation, the end face of the end of the insert rod inserted into the insertion hole is provided with an adjusting slope, and the adjusting slope abuts against the end of the push screw that extends into the insertion hole.

[0012] In the aforementioned crown drill with stable installation, an adjusting block is slidably disposed in the insertion hole. The adjusting block slides along the axial direction of the insertion hole. The end face of the adjusting block near the mounting groove is a concave cavity arranged in a trumpet shape. One end of the insertion rod abuts against the side wall of the concave cavity of the adjusting block. A pushing inclined surface is provided at the bottom of the adjusting block, and the pushing inclined surface abuts against the end of the pushing screw that extends into the insertion hole.

[0013] In the aforementioned type of stable crown drill, the end face of the push screw extending into the socket is arranged with an inclined chamfer.

[0014] The positive effects of the above technical solution are: The aforementioned stable crown drill achieves this by arranging the wall of the limiting perforation on the drill bit, near the bottom of the mounting groove on the drill rod, into an inclined conical surface. Simultaneously, one end of the screw is designed as a threaded end, and the middle of the screw is conical, with the small end connecting to the threaded end and ensuring a consistent cross-sectional area. This design allows for a larger diameter at one end of the limiting perforation after the drill bit is installed in the mounting groove. Furthermore, when the screw is inserted into the limiting perforation, the smaller threaded end enters first, facilitating its passage and preventing the screw end from being blocked by the opening edge. This makes screw installation and removal easier, thus simplifying drill bit replacement. Additionally, when tightening the screw, the outer wall of the conical middle portion of the screw pushes against the conical surface of the limiting perforation, pushing the drill bit towards the bottom of the mounting groove, further enhancing the drill bit's stability after installation. Attached Figure Description

[0015] Figure 1 This is a structural diagram of an embodiment of the present invention for a stable installation of a crown drill. Figure 2 This is a structural diagram of a crown drill rod for stable installation according to the present invention; Figure 3 This is a structural diagram of a screw for installing a crown drill that provides stable mounting according to this utility model; Figure 4 This is a cross-sectional view of a structure of a crown drill that can be installed stably according to this utility model; Figure 5 This is a cross-sectional view of another structure of a crown drill that can be installed stably according to this utility model; Figure 6 This is a cross-sectional view of another structure of a crown drill that can be installed stably according to this utility model.

[0016] In the attached diagram: 1. Drill rod; 11. Mounting groove; 12. Screw hole; 13. Threaded hole; 14. Insertion hole; 15. Deformation groove; 16. Adjustment hole; 111. First mating surface; 112. Second mating surface; 113. Third mating surface; 2. Drill bit; 21. Limiting hole; 22. First positioning surface; 23. Second positioning surface; 24. Third positioning surface; 25. Insertion rod; 211. Conical surface; 251. Adjusting inclined surface; 3. Screw; 31. Threaded end; 4. Push screw; 5. Adjusting block; 51. Cavity; 52. Push inclined surface. Detailed Implementation

[0017] To make the technical means, creative features, objectives, and effects of this utility model easier to understand, the following embodiments are provided in conjunction with the appendix. Figure 1 To be continued Figure 6 The technical solution provided by this utility model is described in detail, but the following content is not intended to limit this utility model.

[0018] Figure 1 This is a structural diagram of an embodiment of the present invention for a stable installation of a crown drill. Figure 2 This is a structural diagram of a crown drill rod for stable installation according to the present invention; Figure 3 This is a structural diagram of a screw for installing a crown drill that provides stable mounting according to this utility model; Figure 4 This is a cross-sectional view of a structure of a crown drill that can be installed stably according to this utility model. Figures 1 to 4 As shown, the crown drill provided in this embodiment, which offers stable installation, includes: a drill rod 1, a drill bit 2, and a screw 3. A recessed mounting groove 11 is formed along the axial direction at one end of the drill rod 1. This groove creates a recessed mounting space at the end of the drill rod 1, providing conditions for the subsequent embedded installation of the drill bit 2. Furthermore, the mounting groove 11 has at least two side walls and a bottom wall, providing conditions for using the side walls and bottom wall as limiting surfaces for the drill bit 2 to improve the accuracy and stability of the drill bit installation. Additionally, a transverse through-hole 21 is formed on the drill bit 2, providing conditions for subsequently confining the drill bit 2 within the mounting groove 11 through the through-hole 21. In addition, screw holes 12 and threaded holes 13 are coaxially arranged on the drill rod 1 and on the two side walls of the mounting groove 11. During installation, the screw 3 passes through the screw hole 12 and through the limiting hole 21 on the drill bit 2, and finally connects and locks with the threaded hole 13. That is, by installing the screw 3 in the mounting groove 11, the purpose of restricting the drill bit 2 in the mounting groove 11 is achieved.

[0019] Specifically, the side of the hole wall of the limiting hole 21 of the drill bit 2, which is close to the bottom of the mounting groove 11, is set as an inclined conical surface 211 arranged along the axial direction of the limiting hole 21. At the same time, the screw 3 is set as a variable cross-section structure. One end of the screw 3 is a threaded end 31, and the middle part of the screw 3 is arranged in a conical shape. The small end of the middle part of the screw 3 is connected to the threaded end 31 and has the same cross-section, so that the cross-section of the threaded end 31 of the screw 3 is minimized, which makes it easier for the screw 3 to be inserted into the limiting hole 21. During installation, the threaded end 31 of screw 3 is connected to the threaded hole 13. The outer wall of the conical middle part of screw 3 abuts against the conical surface 211 of the limiting through hole 21. By continuing to tighten screw 3, the conical outer wall of the middle part of screw 3 gradually pushes the conical surface 211 of the limiting through hole 21, thereby pushing drill bit 2 toward the bottom wall of mounting groove 11, so that drill bit 2 is only pressed into mounting groove 11, improving the stability of drill bit 2 installation. At the same time, since the side of limiting through hole 21 near the bottom of mounting groove 11 is a conical surface 211, limiting through hole 21 is also a variable cross-section hole, thereby increasing the opening at one end of limiting through hole 21, making it easier for the end of screw 3 to pass into limiting through hole 21, avoiding the problem of the end of screw 3 being blocked by the opening edge of limiting through hole 21, making disassembly and assembly more convenient and facilitating the replacement of drill bit 2.

[0020] More specifically, the two sides of the drill bit 2 are designated as the first positioning surface 22 and the second positioning surface 23, respectively. At the same time, the two side walls of the mounting groove 11 are designated as the first mating surface 111 and the second mating surface 112, respectively. This ensures that after the drill bit 2 is installed in the mounting groove 11, the first positioning surface 22 fits into the first mating surface 111, and the second positioning surface 23 fits into the second mating surface 112. This achieves the limitation of the drill bit 2 on both sides after installation in the mounting groove 11, improving the installation accuracy and stability after installation. In addition, the drill bit 2 has a cutting edge at its top and a third positioning surface 24 at its bottom. The bottom wall of the mounting groove 11 is a third mating surface 113. This allows the drill bit 2 to be positioned within the mounting groove 11 by the contact between the third positioning surface 24 and the third mating surface 113. Furthermore, when the screw 3 is tightened, the middle of the screw 3 pushes the third positioning surface 24 of the drill bit 2 against the third mating surface 113 of the mounting groove 11, achieving three-sided positioning of the drill bit 2 within the mounting groove 11 and improving the stability of the drill bit 2 after installation. Preferably, the first positioning surface 22, the second positioning surface 23, and the third positioning surface 24 are all planar, facilitating machining and increasing the contact area.

[0021] More specifically, an extended insert rod 25 is provided at the bottom of the drill bit 2. At the same time, an insertion hole 14 corresponding to the insert rod 25 is provided on the bottom wall of the mounting groove 11. This allows the drill bit 2 to move in the radial direction of the drill rod 1 when the drill bit 2 is installed in the mounting groove 11, by inserting the insert rod 25 into the insertion hole 14, thereby further improving the stability of the drill bit 2 after installation.

[0022] More specifically, the screw hole 12 on the drill rod 1 is a countersunk hole, and the countersunk end of the screw hole 12 is located on the outer wall of the drill rod 1. This allows the head of the screw 3 to be hidden inside the countersunk hole when the screw 3 is passed through the screw hole 12 and connected to the threaded hole 13, thus ensuring the flatness of the outer wall of the drill rod 1 and smoothly realizing the drilling operation.

[0023] More specifically, deformation grooves 15 are symmetrically formed on the drill rod 1 on both sides of the insertion hole 14. The deformation grooves 15 penetrate the side wall of the insertion hole 14, allowing deformation space on the side wall of the insertion hole 14, thus providing conditions for subsequently reducing the diameter of the insertion hole 14. Preferably, the line connecting the deformation grooves 15 on both sides of the insertion hole 14 is perpendicular to the axial direction of the screw hole 12, so that the arrangement direction of the deformation grooves 15 is consistent with the arrangement direction of the mounting groove 11. This allows the deformation grooves 15 to narrow or widen as the two side walls of the deformation grooves 15 move closer or further apart when the screw 3 is tightened or loosened, thereby reducing or expanding the inner diameter of the insertion hole 14. That is, when the drill bit 2 is installed in the mounting groove 11, the insertion hole 14 can be reduced simultaneously when the drill bit 2 is pressed by tightening the screw 3. The insertion rod 25 of the drill bit 2 is clamped by the hole wall of the insertion hole 14, further improving the stability of the drill bit 2 after installation.

[0024] In addition to the structure described above that uses the deformation groove 15 to stably install the plug rod 25 into the socket 14, this embodiment also provides another structure for stably installing the plug rod 25 into the socket 14. Figure 5 This is a cross-sectional view of another structure of a crown drill with stable installation according to this utility model. (See attached image.) Figure 1 , Figure 2 as well as Figure 5 As shown, an adjustment hole 16 is provided radially on the outer side wall of the drill rod 1. One end of the adjustment hole 16 is connected to the insertion hole 14. At the same time, a push screw 4 is provided in the adjustment hole 16, and one end of the push screw 4 extends into the insertion hole 14, so that the adjustment block 5 in the insertion hole 14 can be moved by pushing the push screw 4.

[0025] At this time, an adjusting slope 251 is provided on the end face of the end of the insertion rod 25 that is inserted into the insertion hole 14. After the drill bit 2 is installed in the mounting groove 11, the adjusting slope 251 abuts against the end of the push screw 4 that extends into the insertion hole 14. This allows the end of the push screw 4 to apply force to the adjusting slope 251 when the push screw 4 is turned, pushing the insertion rod 25 toward one side of the insertion hole 14. This allows both sides of the insertion rod 25 to be pressed against the hole wall of the insertion hole 14 and the push screw 4 respectively, eliminating the problem of the drill bit 2 shifting laterally during subsequent use due to the assembly gap between the insertion hole 14 and the insertion rod 25, and further improving the stability of the drill bit 2 after installation.

[0026] In addition to the structure described above, which uses a deformation groove 15 and a strip adjustment slope 251 directly set on the insertion rod 25, this embodiment can also achieve stable installation of the insertion rod 25 in the insertion hole 14 through an auxiliary structure. Figure 6 This is a cross-sectional view of another structure of the crown drill that provides stable installation according to this utility model. (See image below.) Figure 1 , Figure 2 as well as Figure 6 As shown, an adjusting block 5 is slidably disposed within the insertion hole 14, acting as an auxiliary structure on the insertion rod 25. Sliding the adjusting block 5 along the axial direction of the insertion hole 14 provides the conditions for subsequently pushing the insertion rod 25 against the adjusting block 5. Furthermore, the end face of the adjusting block 5 near the mounting groove 11 has a flared cavity 51, and one end of the insertion rod 25 abuts against the side wall of the cavity 51 of the adjusting block 5, so that the end of the insertion rod 25 abuts against the inclined surface of the cavity 51, providing the conditions for subsequently limiting the radial movement of the insertion rod 25 by the adjusting block 5. In addition, the bottom of the adjusting block 5 is provided with a pushing slope 52, which abuts against one end of the pushing screw 4 that extends into the insertion hole 14. This allows the adjusting block 5 to slide within the insertion hole 14 when the pushing screw 4 is turned. The inclined surface of the cavity 51 on the adjusting block 5 pushes the insertion rod 25, which also limits the radial movement of the insertion rod 25, reduces the impact of the assembly gap between the insertion hole 14 and the insertion rod 25, and improves the stability of the drill bit 2 after installation.

[0027] More specifically, the end face of the push screw 4 extending into the insertion hole 14 is arranged with an inclined chamfer. The chamfer forms a bevel at the end of the push screw 4, which can better cooperate with the adjustment slope 251 of the insertion rod 25 or the pushing slope 52 of the adjustment block 5, ensuring that the end of the push screw 4 can normally push the insertion rod 25 or the adjustment block 5 to move. The structural design is more reasonable.

[0028] The crown drill provided in this embodiment, which offers stable installation, includes a drill rod 1, a drill bit 2, and a screw 3. By arranging the wall of the limiting through hole 21 on the drill bit 2, which is close to the bottom of the mounting groove 11 on the drill rod 1, as an inclined conical surface 211, the diameter of one end of the limiting through hole 21 is enlarged. Furthermore, the middle part of the screw 3 is arranged in a conical shape, with its small end connected to the threaded end 31. This allows the screw 3 to be inserted into the limiting through hole 21 with the threaded end 31, which has a smaller cross-section, exiting from the opening of the limiting through hole 21. The larger end is inserted, which makes it easier for the screw 3 to pass through the limiting hole 21, avoiding the problem that the end of the screw 3 is blocked by the edge of the limiting hole 21. This makes it easier to install and remove the screw 3, thus facilitating the replacement of the drill bit 2. Furthermore, by turning the screw 3, the outer wall of the conical middle part of the screw 3 can push the conical surface 211 of the limiting hole 21, pushing the drill bit 2 towards the bottom of the mounting groove 11, so that the drill bit 2 can fit the mounting groove 11 better and improve the stability of the drill bit 2 after installation.

[0029] The above are merely preferred embodiments of the present utility model and are not intended to limit the implementation methods and protection scope of the present utility model. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A crown drill with stable installation, comprising a drill rod, a drill bit, and screws, wherein one end of the drill rod has a recessed mounting groove along its axial direction, the drill bit has a transversely penetrating limiting hole, and the drill rod has coaxially arranged screw holes and threaded holes on its two side walls located in the mounting groove, respectively; during installation, the screw passes through the screw hole and through the limiting hole on the drill bit, and finally connects and locks with the threaded hole, characterized in that... The side of the hole wall of the limiting perforation of the drill bit, near the bottom of the mounting groove, is an inclined conical surface arranged along the axial direction of the limiting perforation. Meanwhile, the screw has a variable cross-section structure, one end of the screw is a threaded end, the middle part of the screw is conical, and the small end of the middle part of the screw is connected to the threaded end and has the same cross-section.

2. The crown drill with stable installation according to claim 1, characterized in that, The two sides of the drill bit are respectively a first positioning surface and a second positioning surface. Meanwhile, the two side walls of the mounting groove are respectively a first mating surface and a second mating surface, which are respectively attached to the first positioning surface and the second positioning surface. The top of the drill bit is provided with a cutting edge, and the bottom of the drill bit is provided with a third positioning surface. The bottom wall of the mounting groove is a third mating surface, and the third positioning surface and the third mating surface are attached to each other.

3. The crown drill with stable installation according to claim 1, characterized in that, The bottom of the drill bit is also provided with an extended insertion rod, and the bottom wall of the mounting groove is provided with an insertion hole corresponding to the insertion rod.

4. The crown drill with stable installation according to claim 1, characterized in that, The screw hole is a countersunk hole, and the countersunk end of the screw hole is located on the outer wall of the drill rod.

5. The crown drill with stable installation according to claim 1, characterized in that, The drill rod is provided with symmetrical deformation grooves on both sides of the insertion hole. The deformation grooves penetrate the side wall of the insertion hole, and the line connecting the deformation grooves on both sides of the insertion hole is perpendicular to the axial direction of the screw hole.

6. The crown drill with stable installation according to claim 1, characterized in that, An adjustment hole is provided on the outer side wall of the drill rod along its radial direction. One end of the adjustment hole is connected to the insertion hole. At the same time, a push screw is provided in the adjustment hole, and one end of the push screw extends into the insertion hole.

7. The crown drill with stable installation according to claim 6, characterized in that, The end face of the insertion rod that is inserted into the socket is provided with an adjustment slope, and the adjustment slope abuts against the end of the push screw that extends into the socket.

8. The crown drill with stable installation according to claim 6, characterized in that, An adjusting block is slidably disposed in the socket. The adjusting block slides along the axial direction of the socket. The end face of the adjusting block near the mounting groove is a concave cavity arranged in a trumpet shape. One end of the plug rod abuts against the side wall of the concave cavity of the adjusting block. A pushing inclined surface is provided at the bottom of the adjusting block. The pushing inclined surface abuts against the end of the pushing screw that extends into the socket.

9. The crown drill with stable installation according to claim 7 or 8, characterized in that, The end face of the push screw extending into the socket is arranged with an inclined chamfer.

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