A multi-blade drill bit

Abstract

This application discloses a multi-blade drill bit, including a drill rod, at least one drill blade at the end of the drill rod, the middle of the drill blade being aligned with the axis of the drill rod and having a breaking section, and multiple drill edges symmetrically arranged circumferentially along the axis of the drill rod on the drill blade; each drill edge has a cutting section at its outer end, and the cutting section has a first cutting edge and a second cutting edge, the second cutting edge being lower than the first cutting edge along the axial direction of the drill rod; the end of the drill rod has a guide structure for guiding the discharge of chips, and the outer wall of the drill rod has a conveying groove for conveying chips, the guide structure being connected to the conveying groove; so that when the drill bit is working, the breaking section first performs preliminary crushing on the central area of ​​the workpiece, then the first cutting edge performs the main cutting, and the second cutting edge continues to perform auxiliary cutting on the material after preliminary cutting, thus taking into account the basic cutting ability without increasing the number of drill edges; at the same time, after the chips are formed, they are transitioned into the conveying groove by the guide structure, reducing the retention of chips at the end of the drill bit.

Description

Technical Field

[0001] This application relates to the technical field of drill bits, and in particular to a multi-bladed drill bit. Background Technology

[0002] When drilling into the main body of a reinforced concrete building, a drill bit is typically used to process the building structure. This type of drill bit generally includes a main body, a clamping groove at one end of the main body, and a cutting head at the other end. The main body usually has a spiral chip removal groove, and the cutting head cuts the building structure during high-speed rotation. To ensure cutting capability, existing cutting heads are mostly made of alloy material and have three circumferentially arranged inserts. These three inserts intersect to form six cutting edges, thus enabling the drilling of the building structure.

[0003] However, drill bits typically rely on alloy materials to achieve cutting functionality. The cost of alloy materials has been rising continuously in recent years, leading to a corresponding increase in the manufacturing cost of drill bits. At the same time, the downstream market's requirements for the cost-effectiveness of drill bit products are gradually increasing. This makes the existing drill bit structures with higher alloy content insufficient in terms of cost control. Under the premise of ensuring that the drill bit has basic cutting and drilling capabilities for the building structure, it is necessary to reduce the manufacturing cost of the drill bit and improve the cost-effectiveness of the product. Summary of the Invention

[0004] To reduce manufacturing costs and improve cost-effectiveness of drill bits while ensuring they have basic cutting capabilities for the building structure, a multi-bladed drill bit is provided.

[0005] The above-mentioned objective of this application is achieved through the following technical solution: A multi-blade drill bit includes a drill rod, at least one drill blade at the end of the drill rod, the middle of the drill blade being aligned with the axis of the drill rod and having a breaking section, and a plurality of drill edges symmetrically arranged circumferentially along the axis of the drill rod on the drill blade; each drill edge has a cutting section at its outer end, and the cutting section has a first cutting edge and a second cutting edge, the height of the second cutting edge along the axial direction of the drill rod being lower than that of the first cutting edge. The drill rod end is provided with a flow guide structure for guiding the discharge of debris, and the outer wall of the drill rod is provided with a conveying groove for conveying debris. The flow guide structure is connected to the conveying groove.

[0006] By adopting the above technical solution, the drill bit first performs preliminary crushing of the workpiece's central area by the crushing section during operation, then the first cutting edge performs the main cutting, and the second cutting edge continues to perform auxiliary cutting on the material after preliminary cutting. This achieves basic cutting capability without increasing the number of drill edges. At the same time, after the chips are formed, they are transitioned into the conveying groove by the guiding structure, reducing chip retention at the drill bit tip. This improves chip removal while maintaining basic cutting capability. While ensuring the drill bit has basic drilling capability, it reduces dependence on high-cost alloy materials and reduces chip accumulation in the cutting head area, thereby improving the drill bit's operational stability.

[0007] Preferably, the flow guiding structure includes a breaking flow guiding part and a cutting flow guiding part disposed between adjacent drill bits, wherein the breaking flow guiding part is located at the end of the drill bit near the breaking part, and the cutting flow guiding part is located at the end of the drill bit near the second cutting edge.

[0008] By adopting the above technical solution, the guide section is arranged separately according to the chip generation area, which shortens the transition distance between the chip generation location and the subsequent chip removal path, and reduces the cross accumulation of chips at the drill bit end.

[0009] Preferably, the crushing guide section and the cutting guide section are arranged at intervals along the circumference of the drill rod and are distributed correspondingly to the drill bit, and a plurality of the crushing guide sections and the cutting guide sections converge into a small number of the conveying grooves.

[0010] By adopting the above technical solution, the debris guided by multiple guide sections is collected into a smaller number of conveying troughs, so that the debris is transformed from being generated in a dispersed manner to being guided and collected nearby, reducing the local accumulation between the drill bit and the drill rod end, and maintaining the continuity of the chip removal path.

[0011] Preferably, both the breaking guide and the cutting guide are connected to the side of the drill bit near the second cutting edge, and are used to limit the radial and circumferential position of the drill bit.

[0012] By adopting the above technical solution, while undertaking the function of guiding the flow, it also plays an auxiliary role in positioning and limiting the drill bit. If the drill bit is positioned by relying on a single contact surface during the assembly and welding process, radial displacement or circumferential angular deviation is likely to occur. However, when the breaking and cutting flow guiding parts and the cutting edge form a restriction on the position of the drill bit with one side of the drill bit, the relative position of the drill bit before and after welding can be more stable.

[0013] Preferably, both the crushing guide and the cutting guide include a guide groove and guide blades located on both sides of the guide groove.

[0014] By adopting the above technical solution, the guide groove can provide a transition space for the debris, while the guide blades on both sides restrict the movement direction of the debris, so that the debris moves along the extension direction of the guide groove. The debris generated in the crushing zone and the cutting zone is guided to the subsequent conveying trough for better effect.

[0015] Preferably, the conveying trough is spiral-shaped, and the outer wall of the drill rod at the end away from the drill bit has a spiral-shaped discharge trough. The conveying trough is connected to the discharge trough, and multiple conveying troughs converge into a smaller number of discharge troughs.

[0016] By adopting the above technical solution, the drill bit itself is in a rotating state when working, and the spiral channel is conducive to gradually carrying the debris away from the end area of ​​the drill rod along the axial direction; at the same time, multiple conveying channels converge into a smaller number of discharge channels, so that the relatively dispersed debris flow at the front end forms a more concentrated discharge path at the rear end, and a continuous conveying link from the front end to the rear end is constructed on the outer wall of the drill rod, reducing the accumulation of debris during the conveying process.

[0017] Preferably, the cutting section has a first guide groove along the axial direction of the drill rod, the first guide groove is located between the first cutting edge and the second cutting edge, and the bottom of the first guide groove is flush with the outer wall of the drill rod.

[0018] By adopting the above technical solution, a local guide space can be formed between the two cutting edges, so that the chips generated during the cutting process can be transferred out between the two edges in a timely manner. The bottom of the groove is flush with the outer wall of the drill pipe, which reduces chip stagnation caused by local bosses or steps and alleviates chip accumulation near the cutting part.

[0019] Preferably, the cutting part is provided with a guide surface between the first cutting edge and the second cutting edge, the guide surface is inclined along the radial direction of the drill rod, and the guide surface is connected to the first guide groove.

[0020] By adopting the above technical solution, the guide surface can form an oblique transition channel for this part of the debris and further connect with the first guide groove, reducing the local retention of debris between the two cutting edges.

[0021] Preferably, the cutting part is further provided with a third guide groove along the axial direction of the drill rod, and the third guide groove is aligned with the end of the second cutting edge along the axial direction of the drill rod.

[0022] By adopting the above technical solution, the second cutting edge, as an auxiliary cutting part, will form chips near its end when participating in cutting, so that the second cutting edge can also have a discharge outlet while assisting in cutting, thereby reducing the chip accumulation at the second cutting edge.

[0023] In summary, this application has at least the following beneficial effects: 1. By setting a crushing section in the middle of the drill bit and setting a first cutting edge and a second cutting edge with a height difference at the outer end of the drill bit, the workpiece is first crushed in the central area during the drilling process, and then the first cutting edge performs the main cutting, while the second cutting edge performs the supplementary cutting. This transforms the cutting process from a single cutting edge acting in a concentrated manner to a staged process, dispersing the cutting load without increasing the number of drill bits, and reducing the dependence on high-strength alloy materials while maintaining basic drilling capability. 2. By using crushing guide sections and cutting guide sections to be set up according to the chip generation area and connected to the conveying trough, multiple guide sections converge into a smaller number of conveying troughs, and multiple conveying troughs converge into a smaller number of discharge troughs, so that the chips can enter the guide path nearby after generation and be transported in a concentrated manner, so that the chips change from a dispersed state to a continuous flow along the main channel, reducing the local accumulation of chips at the drill bit end. 3. By setting a first guide groove, a guide surface and a third guide groove in the cutting part and connecting them with the conveying groove, the chips generated in different directions in the cutting area can enter the conveying groove through axial transition, radial transition and end outlet paths, respectively, further reducing the chip accumulation in the cutting area. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the drill bit structure; Figure 2 This is a schematic diagram of the structure between the drill pipe and the drill bit; Figure 3 This is a schematic diagram of the drill bit structure.

[0025] Reference numerals: 1. Drill rod; 11. Conveying trough; 12. Discharge trough; 2. Drill blade; 21. Drill bit; 22. Cutting part; 221. First cutting edge; 222. Second cutting edge; 223. First guide groove; 224. Guide surface; 225. Third guide groove; 3. Crushing part; 4. Guide structure; 41. Crushing guide part; 42. Cutting guide part; 43. Guide groove; 44. Guide edge. Detailed Implementation

[0026] The following section provides a more detailed description, in conjunction with the accompanying diagrams: As attached Figure 1 and attached Figure 2As shown, a multi-blade drill bit includes a drill rod 1 and a drill blade 2. The drill rod 1 is a cylindrical rod body, and the axis of the drill rod 1 serves as the rotation center axis of the entire drill bit. One end of the drill rod 1 is a connecting end, used to connect with the clamping structure of a power tool or drilling machine, and the other end of the drill rod 1 is a working end, used to install the drill blade 2. The drill blade 2 is preferably fixed to the end face of the drill rod 1 by welding. During assembly, the center of the drill blade 2 is aligned with the axis of the drill rod 1, so that the drill blade 2 rotates coaxially around the axis of the drill rod 1 during rotation, avoiding unstable cutting caused by eccentricity.

[0027] The drill bit 2 has a block-like structure. Preferably, there are two drill bits 2, which are staggered and have a crushing section 3 formed at the intersection. The crushing section 3 is preferably a cone-shaped structure that protrudes forward. Its shape can be a pyramid with multiple edges, so that it forms a local stress concentration area when it contacts the workpiece. When the drill bit rotates and advances towards the workpiece, the crushing section 3 first contacts the central area of ​​the workpiece, crushing or impacting the material in that area to form cracks or fragments, creating conditions for subsequent cutting.

[0028] As attached Figure 2 and attached Figure 3 As shown, a single drill bit 2 is symmetrically provided with two drill edges 21 about the axis of the drill rod 1. The number of drill edges 21 is preferably four and they are symmetrically arranged around the circumference of the drill rod 1. The four drill edges 21 are distributed in a cross shape around the crushing part 3, so that each drill edge 21 participates in cutting in turn during rotation. The drill edges 21 are flat in shape, and the top of the drill edge 21 is inclined along the radial direction of the drill rod 1. The higher end of the drill edge 21 along the radial direction of the drill rod 1 is connected to the axis of the drill rod 1, and the lower end of the drill edge 21 along the radial direction of the drill rod 1 extends outward along the radial direction of the drill rod 1. Each drill edge 21 has two adjacent cutting surfaces, and the two cutting surfaces of each drill edge 21 are inclined relative to each other and have different cutting surface areas.

[0029] Each drill bit 21 extends from the inside out. The inner end of the drill bit 21 is adjacent to the crushing part 3, and the outer end of the drill bit 21 forms a cutting part 22. The cutting part 22 has a first cutting edge 221 and a second cutting edge 222. The first cutting edge 221 is located in front of the second cutting edge 222 along the rotation direction of the drill rod 1. When the drill rod 1 rotates and advances, the first cutting edge 221 first contacts the crushed hole wall and performs the main cutting on the crushed hole wall. Then the second cutting edge 222 enters the cutting area and continues to cut the weakened material. By staggering the first cutting edge 221 and the second cutting edge 222, the cutting process is spatially dispersed, avoiding a single cutting edge bearing the load for a long time.

[0030] A conveying groove 11 is opened on the outer wall of the drill rod 1. The conveying groove 11 extends along the axial direction of the drill rod 1 and is spirally arranged around the outer circumference of the drill rod 1. The end of the conveying groove 11 near the drill bit 2 is open and connected to the gap area between two adjacent drill bits 21. There are four conveying grooves 11. The spiral conveying groove 11 cooperates with the rotational motion to gradually convey the debris in the gap area between two adjacent drill bits 21 to the end away from the drill bit 2 along the groove.

[0031] A flow guiding structure 4 is provided in the gap area between two adjacent drill bits 21 at the end of the drill rod 1. The flow guiding structure 4 is arranged along the axial direction of the drill rod 1. The flow guiding structure 4 includes a breaking flow guiding part 41 near the center area and a cutting flow guiding part 42 near the outer side. The breaking flow guiding part 41 is located between adjacent drill bits 21 and near the breaking part 3. One end of the breaking flow guiding part 41 is connected to the connection point of the two drill bits 2, and the other end of the breaking flow guiding part 41 extends into the conveying groove 11. The cutting flow guiding part 42 is located between adjacent drill bits 21 and near the second cutting edge 222. One end of the cutting flow guiding part 42 is connected to the drill bit 21 near the second cutting edge 222, and the other end of the cutting flow guiding part 42 extends into the conveying groove 11, so that the debris in the breaking flow guiding part 41 and the cutting flow guiding part 42 can be guided into the conveying groove 11.

[0032] Each crushing guide section 41 and cutting guide section 42 is arranged at intervals along the circumference of the drill rod 1 and corresponds to the position of each drill bit 21. A set of guide structures 4 is provided on one side of each drill bit 21. The crushing guide section 41 and cutting guide section 42 of each set of guide structures 4 are connected to a single conveying trough 11. The four sets of guide structures 4 are connected to four conveying troughs 11 respectively. The debris from the crushing guide section 41 and cutting guide section 42 is collected into a smaller number of conveying troughs 11, so that the debris is transformed from being generated in a dispersed manner to being guided and collected nearby, reducing the local accumulation between the drill bit 2 and the end of the drill rod 1.

[0033] The breaking guide section 41 and the cutting guide section 42 are preferably in contact with or welded to the side of the drill bit 21 near the second cutting edge 222. The guide structure 4 not only serves as a guide for the debris, but also forms an auxiliary limit for the drill bit 2. When the drill bit 2 is welded to the end of the drill rod 1, the contact relationship between the guide structure 4 and the drill bit 21 can limit the radial displacement of the drill bit 2. At the same time, through the circumferential distribution of multiple guide structures 4, the circumferential position of the drill bit 2 is constrained, so that the drill bit 2 maintains a predetermined angular position during assembly.

[0034] Each crushing guide section 41 and cutting guide section 42 has a guide groove 43 extending from the crushing section 3 toward the conveying groove 11 on its surface. Guide blades 44 are formed on both sides of the guide groove 43. The opening of the guide groove 43 faces the direction of the debris source, so that the debris moves along its extension direction after entering the guide groove 43. The guide blades 44 restrict the lateral movement of the debris, so that the debris is not easy to deviate from the predetermined path.

[0035] A first guide groove 223 is provided between the first cutting edge 221 and the second cutting edge 222. The first guide groove 223 extends along the axial direction of the drill rod 1, forming a local cavity area between the first cutting edge 221 and the second cutting edge 222. The debris can enter this area without accumulating at the cutting edge. The bottom of the first guide groove 223 is flush with the outer wall of the drill rod 1, so that the debris is not blocked by a significant step when passing through the first guide groove 223. After passing through the first guide groove 223, the debris will be collected again in the conveying groove 11.

[0036] A guide surface 224 is provided between the first cutting edge 221 and the second cutting edge 222. The guide surface 224 is arranged radially inclined. One end of the guide surface 224 is close to the cutting area, and the other end of the guide surface 224 is connected to the first guide groove 223, so that some of the radially thrown debris can enter the first guide groove 223 through the inclined guide surface, thereby forming a transition path from radial to axial.

[0037] A third guide groove 225 is provided near the end of the second cutting edge 222 in the cutting part 22. The third guide groove 225 is aligned with the end of the second cutting edge 222 in the axial direction, so that the chips formed at the position of the second cutting edge 222 can directly enter the third guide groove 225 for chip removal. After passing through the third guide groove 225, the chips will be collected in the conveying groove 11 through the outer wall of the drill rod 1, further improving the chip removal path inside the cutting part 22.

[0038] As attached Figure 1 and attached Figure 2 As shown, a spiral discharge trough 12 is opened on the outer wall of the end of the drill rod 1 away from the drill bit 2. The discharge trough 12 is connected to the conveying trough 11. There are two discharge troughs 12. During the conveying process, the debris in the multiple conveying troughs 11 is further collected into a smaller number of discharge troughs 12. Preferably, two adjacent conveying troughs 11 are collected into one of the discharge troughs 12, and two sets are provided so that the debris forms a concentrated discharge path in the rear section of the drill rod 1, so that the debris forms a continuous channel from the generation position to the discharge position, reducing the accumulation in the middle.

[0039] The inner walls of the conveying trough 11 and the discharge trough 12 facing the end of the drill rod 1 with the drill blade 2 are convex arcs, and the inner walls of the conveying trough 11 and the discharge trough 12 facing away from the end of the drill rod 1 with the drill blade 2 are concave arcs. This can increase the conveying or discharging area between the conveying trough 11 and the discharge trough 12 and reduce the phenomenon of debris getting stuck in the conveying trough 11 or the discharge trough 12.

[0040] The implementation principle of this embodiment: The drill rod 1 drives the drill bit 2 to rotate around the axis. The crushing part 3 in the middle of the drill bit 2 first contacts the central area of ​​the workpiece, locally crushing the workpiece, causing cracks in the material in the central area and reducing the overall structural strength. Subsequently, multiple drill edges 21 distributed in the circumferential direction participate in the cutting in sequence. The first cutting edge 221 in front performs the main cutting on the crushed area, and the second cutting edge 222 in the rear performs supplementary cutting on the material after the initial cutting. This changes the cutting process from a single cutting to a staged completion, thereby dispersing the cutting load without increasing the number of drill edges 21.

[0041] The chips generated during the cutting and crushing process are guided by the crushing guide section 41 near the center and the cutting guide section 42 near the outer side, respectively, so that the chips enter the corresponding conveying trough 11. The conveying trough 11 conveys the chips axially under the action of the rotation of the drill rod 1, and further collects them to the discharge trough 12 for discharge, thereby forming a continuous chip discharge path from the end of the drill bit to the rear section of the outer wall of the drill rod 1, so that the chips are transformed from dispersed generation to concentrated conveying, reducing the retention and accumulation of chips at the end of the drill bit and in the cutting area.

[0042] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of protection claimed in this application.

Claims

1. A multi-bladed drill bit, comprising a drill rod (1), characterized in that, The drill rod (1) has at least one drill blade (2) at its end. The middle part of the drill blade (2) is aligned with the axis of the drill rod (1) and has a breaking part (3). The drill blade (2) has multiple drill edges (21) symmetrically arranged around the axis of the drill rod (1). Each drill edge (21) has a cutting part (22) at its outer end. The cutting part (22) has a first cutting edge (221) and a second cutting edge (222). The height of the second cutting edge (222) along the axial direction of the drill rod (1) is lower than that of the first cutting edge (221). The drill rod (1) has a flow guide structure (4) at its end for guiding the discharge of debris, and the outer wall of the drill rod (1) has a conveying groove (11) for conveying debris. The flow guide structure (4) is connected to the conveying groove (11).

2. A multi-blade drill bit according to claim 1, characterized in that, The flow guiding structure (4) includes a breaking flow guiding part (41) and a cutting flow guiding part (42) disposed between adjacent drill bits (21). The breaking flow guiding part (41) is located at the end of the drill bit (21) near the breaking part (3), and the cutting flow guiding part (42) is located at the end of the drill bit (21) near the second cutting edge (222).

3. A multi-blade drill bit according to claim 2, characterized in that, The crushing guide section (41) and the cutting guide section (42) are arranged circumferentially along the drill rod (1) and are distributed correspondingly to the drill bit (21). A plurality of the crushing guide sections (41) and the cutting guide sections (42) converge into a small number of the conveying grooves (11).

4. A multi-blade drill bit according to claim 2, characterized in that, Both the breaking guide (41) and the cutting guide (42) are connected to the side of the drill bit (21) near the second cutting edge (222) and are used to limit the radial and circumferential position of the drill bit (2).

5. A multi-blade drill bit according to claim 2, characterized in that, Both the crushing guide section (41) and the cutting guide section (42) include a guide groove (43) and guide blades (44) located on both sides of the guide groove (43).

6. A multi-blade drill bit according to claim 1, characterized in that, The conveying trough (11) is spiral-shaped, and the drill rod (1) has a spiral discharge trough (12) on the outer wall at the end away from the drill bit (2). The conveying trough (11) is connected to the discharge trough (12), and multiple conveying troughs (11) converge into a smaller number of discharge troughs (12).

7. A multi-blade drill bit according to claim 1, characterized in that, The cutting part (22) has a first guide groove (223) along the axial direction of the drill rod (1). The first guide groove (223) is located between the first cutting edge (221) and the second cutting edge (222). The bottom of the first guide groove (223) is flush with the outer wall of the drill rod (1).

8. A multi-blade drill bit according to claim 7, characterized in that, The cutting part (22) is provided with a guide surface (224) between the first cutting edge (221) and the second cutting edge (222). The guide surface (224) is inclined along the radial direction of the drill rod (1) and is connected to the first guide groove (223).

9. A multi-blade drill bit according to claim 1, characterized in that, The cutting part (22) is also provided with a third guide groove (225) along the axial direction of the drill rod (1), and the third guide groove (225) is aligned with the end of the second cutting edge (222) along the axial direction of the drill rod (1).

Images