A bta drill bit having a shock absorbing structure and method of use

Abstract

The application discloses a BTA drill bit with a damping structure and a use method, and belongs to the technical field of mechanical machining. The structure comprises a drill bit component. The drill bit component comprises a guide block, a blade, a blade seat, an O-shaped ring, a drill bit and an outer pipe. The device is fixed with the O-shaped ring through the boss structure on the drill bit rod to perform damping. Then, cooling liquid is passed between the outer pipe and the drill bit. Part of the cooling liquid flows into a chip removal channel through the inclined hole on the drill bit rod to promote chip removal. The other part of the cooling liquid flows into a working area through the circular hole on the drill bit step to cool the blade, and simultaneously drives the cut-off chips to flow into the chip removal channel. Finally, the damping, cooling and chip removal effects are realized. The application can realize the damping and cooling functions, better guarantees the coaxiality of machining, reduces the damage of the drill bit, and therefore has the characteristics of simple structure and long service life.

Description

Technical Field

[0001] This invention pertains to deep hole machining technology in the field of mechanical processing, specifically relating to a BTA drill bit with a vibration damping structure and its usage method. Background Technology

[0002] During deep hole machining, the large contact area between the tool and the workpiece can easily cause vibration, leading to decreased machining accuracy and deterioration of surface quality. The large contact area also generates more cutting heat, which can easily cause tool overheating and accelerated wear, affecting machining accuracy and efficiency. Cutting fluid and chips will accumulate in the machining area, and if they are not removed in time, they will also affect machining accuracy and efficiency.

[0003] Patent EP3231544B1 discloses a jetting deep hole drill, which consists of a replaceable drill bit, drill rod, chuck, connector and flange. However, the outer tube of this patent cannot be disassembled, and there are no jet holes or cooling holes, nor is there a good method to promote chip removal for the inner hole chip removal channel.

[0004] Patent application CN201910324413.8 discloses an intelligent high-strength BTA drill bit for deep hole machining, comprising a BTA drill bit and a drill rod. A continuous coolant channel is coaxially formed within the drill rod. The BTA drill bit is connected to the head end of the drill rod, and the tail section of the drill rod has external square threads. Symmetrical jet holes communicating with the coolant channel are formed on the head section of the drill rod. The jet holes follow a cosine pattern with a larger outer diameter and a smaller inner diameter, and the axes of the two jet holes are in the same plane as the coolant channel axis. However, machining these cosine pattern jet holes is difficult and impractical. Furthermore, the patent involves a small number of jet holes located at the drill rod throat, limiting flushing capacity. Since most BTA drill bits employ external cooling and internal chip removal, coolant contamination and waste occur, and external cooling cannot effectively cool the drill bit from within. Additionally, the split structure has poor overall structural rigidity, and the drill bit and drill rod are prone to loosening during machining.

[0005] Patent application CN201821065805.4 discloses a BTA deep hole drilling bit with jet holes, including a BTA drill bit and a connecting rod connected to the front end of the BTA drill bit; the connecting rod is a through tube with multiple jet holes evenly arranged along the circumference; the intersection of the jet hole axis and the connecting rod axis is located after the jet hole, but the jet holes in this patent are only arranged in a circular distribution at the throat, with many openings reducing the structural rigidity of the drill bit, and the slow flow rate is not conducive to chip removal. Since most BTA drill bits adopt the method of external cooling and internal chip removal, it will cause coolant pollution and waste, and external cooling cannot effectively cool down from the inside of the drill bit; in addition, the split structure has poor overall structural rigidity, and the drill bit and drill rod are prone to loosening during machining. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a BTA drill bit with a shock-absorbing structure. Therefore, the drill bit is required to have good shock absorption, cooling and drainage functions to ensure machining accuracy, reduce tool wear and improve machining efficiency.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] In a first aspect, the present invention also provides a BTA drill bit with a shock-absorbing structure, comprising a drill head and a drill rod, the drill head and the drill rod being integrally formed, and a cutting tool being provided on the drill head; the rear half of the drill head is also provided with a thread, which is used to realize the connection between the drill head and the outer tube; and a plurality of bosses are provided on the drill rod, and an O-ring is fitted on each boss; and a chip removal channel is provided in the center of the drill bit along the axial direction of the drill bit; a plurality of jet holes are also provided on the drill rod, the axis of the jet holes being inclined; and a cooling hole is also provided on the drill head; when the drill bit and the outer tube are threaded together, a gap is formed between the outer tube and the drill rod, and the coolant enters from the gap between the two, part of which enters the cooling hole and part of which enters the jet hole.

[0009] As a further technical solution, the front end of the drill bit head is conical, the rear end of the drill bit head is a stepped cylindrical shape, and the thread is formed at the rear end of the drill bit head.

[0010] As a further technical solution, the stepped cylindrical shape includes a first cylindrical section with a large diameter and a second cylindrical section with a small diameter, and the thread is formed on the second cylindrical section.

[0011] As a further technical solution, guide strips are installed on the first cylindrical section.

[0012] As a further technical solution, the axis of the cooling hole is parallel to the axis of the drill bit.

[0013] As a further technical solution, two cooling holes are provided, symmetrically arranged with respect to the axis of the drill bit.

[0014] As a further technical solution, the angle between the jet hole and the drill bit axis is 30-60°.

[0015] As a further technical solution, the jet holes are arranged in multiple rings, with multiple holes arranged in each ring.

[0016] As a further technical solution, the boss is provided in multiple rings, with multiple bosses in each ring.

[0017] Secondly, the present invention also provides a method for using a BTA drill bit with a shock-absorbing structure, as follows:

[0018] The drill bit and outer tube are threaded together, and a gap is formed between the outer tube and the drill rod. After the coolant enters through the gap, part of the coolant flows through the cooling hole to cool the cutting edge on the drill bit. Then, this part of the coolant flows back to the chip removal channel in the middle of the drill bit with the chips, forming an internal cooling and internal chip removal circulation structure. Another part of the coolant is ejected from the jet hole, which then pushes the chips inside the chip removal channel to move towards the tail of the drill rod. During the drilling process, the coolant that enters the chip removal channel through the jet hole flows backward as a whole, reducing the air pressure inside the drill rod. This makes the pressure at the drill bit head greater than the pressure inside the chip removal channel, thereby accelerating the liquid flow. At the same time, the coolant ejected from the jet hole can also effectively clean the hole wall and accelerate the discharge of chips.

[0019] The beneficial effects of this invention are as follows:

[0020] 1. Unlike other technologies, this invention integrates the drill bit head and drill rod into a single structure, enhancing the rigidity of the drill rod during drilling and increasing processing stability. The internal cooling system effectively removes heat during processing, reducing thermal stress and preventing fatigue failure. Since internal cooling has a larger contact area than external cooling, it can remove more heat, thus improving the drill bit's processing efficiency. Furthermore, the separate structure has poor overall structural rigidity, and the drill bit and drill rod are prone to loosening during processing; the integrated design effectively avoids this drawback. The lack of a damping structure in the integrated design can lead to excessive local stress and breakage; the added damping structure requires protection and replacement. The outer tube prevents the O-ring from directly contacting the hole wall, reducing wear and facilitating replacement.

[0021] 2. The jet holes of this invention are conical with a large outer opening and a small inner opening. This facilitates processing and increases jet pressure. Each ring of jet holes is evenly distributed along the circumference of the drill rod and arranged along the axial direction of the drill rod from the throat to the tail. This can effectively increase the flow rate of the coolant and reduce the eddy phenomenon caused by turbulence. This invention achieves both cooling and chip removal through the cooperation of jet holes, cooling holes, and chip removal channels.

[0022] 3. The present invention uses an O-ring as a damping structure, which can effectively absorb the vibration of the tool during drilling and improve machining accuracy. Attached Figure Description

[0023] Figure 1 : An assembly drawing of a BTA drill bit with a shock-absorbing structure according to the present invention;

[0024] Figure 2 : A cross-sectional view of a BTA drill bit with a shock-absorbing structure according to the present invention;

[0025] Figure 3View of a BTA drill bit with a shock-absorbing structure mounted on a clamp according to the present invention;

[0026] In the diagram: 1. Boss, 2. Guide block, 3. Blade, 4. Blade, 5. Blade holder, 6. Blade, 7. O-ring, 8. Drill head, 9. Outer tube, 10. Jet hole, 11. Cooling hole, 12. Chip removal channel, 13. Drill rod. Detailed Implementation

[0027] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0028] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0029] For ease of description, the words "up," "down," "left," and "right" appearing in this invention only indicate that they are consistent with the up, down, left, and right directions of the accompanying drawings themselves, and do not limit the structure. They are merely for the purpose of facilitating the description of this invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0031] like Figures 1 to 3As shown, the drill bit in this embodiment includes a drill head 8 and a drill rod 13, which are integrally formed. The drill head 8 is provided with blades 3, 4, and 6; blade 6 is mounted on a blade holder 5. The rear half of the drill head 8 is also provided with threads, which are used to connect the drill bit to the outer tube 9. Several bosses 1 are provided on the drill rod 13, and an O-ring 7 is fitted on each boss 1. Along the axis of the drill bit, there is a chip removal channel 12 at the center inside the drill bit. Several jet holes 10 are also provided on the drill rod 13. The axes of the jet holes 10 are inclined, allowing the liquid flowing from the jet holes 10 to jet towards the inside of the drill rod and simultaneously towards the rear of the drill rod, thereby pushing the debris located inside the chip removal channel 12 along the chip removal channel 12 towards the tail of the drill rod. Cooling holes 11 are also provided. After the drill bit and the outer tube 9 are threaded together, a gap is formed between the outer tube 9 and the drill rod 13. After the coolant enters through the gap between the two, part of the coolant flows through the cooling holes 11 to cool the cutting edge on the drill bit. Then, this part of the coolant flows back to the chip removal channel in the middle of the drill bit with the chips, forming an internal cooling and internal chip removal circulation structure. Another part of the coolant is ejected from the jet hole 10 and then pushes the chips inside the chip removal channel 12 to move towards the tail of the drill rod along the chip removal channel 12. During the drilling process, since the coolant entering the chip removal channel 12 through the jet hole flows backward as a whole, it can reduce the air pressure at the front, thereby making the pressure at the drill bit head greater than the pressure inside the chip removal channel 12, which can accelerate the liquid flow. At the same time, the coolant ejected from the jet hole can also effectively clean the hole wall and accelerate the discharge of chips.

[0032] Furthermore, in this embodiment, preferably, the jet hole 10 and the drill rod axis form an angle of 20-40°, because the flow velocity is normally distributed at around 30°, and the highest flow velocity is about 30°. Preferably, a 30° angle is used. This needs to be considered when designing the angle between the jet hole 10 and the drill rod axis.

[0033] Furthermore, in this embodiment, multiple rings of jet holes 10 are arranged along the axial direction of the drill bit body, with multiple jet holes 10 in each ring; each jet hole 10 is located between two adjacent protrusions 1. The specific number of jet holes 10 is determined according to the length, and this arrangement ensures that it promotes the discharge of the entire drill bit, while the certain distance also ensures the pressure of the outflowing liquid. The jet holes in each ring are evenly distributed along the circumference of the drill bit and arranged along the axial direction of the drill bit from the throat to the tail, which can effectively increase the flow rate of the coolant and reduce the eddy phenomenon formed by turbulence; the present invention achieves both cooling and chip removal through the cooperation of jet holes, cooling holes, and chip removal channels.

[0034] Furthermore, the jet orifice 10 is a cone shape with a large outer opening and a small inner opening, which facilitates processing and increases jet pressure. The cone orifice is distributed from the throat to the tail of the drill bit, which can provide greater flushing force.

[0035] Furthermore, in this embodiment, the end of the drill bit is provided with a cooling hole 11. Two cooling holes 11 are arranged at the junction of the drill bit and the working area to facilitate cooling and lubrication of the working area.

[0036] Furthermore, in this embodiment, the aforementioned protrusions are arranged in multiple rings along the axial direction of the drill bit body, with multiple protrusions in each ring; each protrusion is provided with an O-ring 7, which mainly serves to dampen vibrations in the drill bit. Preferably, the boss 1 on the drill bit and the O-ring 7 adopt a transition fit.

[0037] Furthermore, in this embodiment, four holes are symmetrically opened on the outer wall of the drill bit head, and the four holes are on the same horizontal plane, mainly for installing four guide blocks 2.

[0038] Furthermore, in this embodiment, the front end of the drill bit head is conical, and the rear end of the drill bit head is a stepped cylindrical shape. The thread is formed at the rear end of the drill bit head. The stepped cylindrical shape includes a first cylindrical section with a large diameter and a second cylindrical section with a small diameter. The thread is formed on the second cylindrical section, and a guide bar is provided on the first cylindrical section.

[0039] Furthermore, in this embodiment, the axis of the cooling hole is parallel to the axis of the drill bit. Two cooling holes are provided, symmetrically arranged with respect to the axis of the drill bit.

[0040] When using the drill bit, install it on the tool holder, tighten the tool holder with a wrench, and adjust the position of the drill bit to avoid misalignment and tilting, thus ensuring good coaxiality.

[0041] Furthermore, in the BTA drill bit with shock absorption device of this patent, the inner wall of the drill bit has three small holes of the same diameter evenly arranged along the inner wall, and the three small holes are respectively used for the blade holder 5, the blade 3, and the blade 4; the blade holder 5 is provided with the blade 6.

[0042] Furthermore, the drill bit insert is capable of cutting the entire diameter of the hole and has a insert holder on each individual insert section. This is to prevent chipping and improve chip adhesion. By adjusting the geometry of the insert and the shape of the guide block, the geometric angle of the cutting edge can be changed, thereby improving the curling state of the chips, reducing chip adhesion, and improving the quality of the machined surface. At the same time, the unevenly distributed inserts can also increase the pressure and flow rate of the cutting fluid, further improving cutting conditions. In addition, the uneven distribution of the inserts can also adjust the coaxiality of the machine tool spindle and the drill bushing, select a suitable drill bushing diameter, and replace excessively worn drill bushings in a timely manner, thereby improving machining accuracy and efficiency.

[0043] In this embodiment, after the coolant flows through the gap between the drill bit and the outer tube, it cools the cutting edge through the cooling hole 11, and then flows back to the chip removal channel in the middle of the drill bit, forming a circulation structure of internal cooling and internal chip removal. The tail of the drill bit adopts symmetrically distributed jet holes 10; during the drilling process, the backward flow of liquid reduces the air pressure at the front, thereby causing the pressure in the working area to be greater than the pressure inside the hole, thus accelerating the liquid flow, effectively cleaning the hole wall and accelerating the discharge of debris.

[0044] The boss 1 at the tail of the drill bit is used to install the O-ring 7, which can effectively fix the O-ring 7. The O-ring 7 is made of nylon, which reduces the eccentricity caused by vibration and the compression of the hole wall, thus ensuring good processing quality and coaxiality of the hole.

[0045] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A BTA drill bit with a vibration damping structure, characterized in that, The system includes a drill head and a drill rod, which are integrally formed. A cutting tool is mounted on the drill head. The rear half of the drill head is threaded for connection between the drill head and the outer tube. Several bosses are mounted on the drill rod, each fitted with an O-ring. A chip removal channel is located at the center of the drill head's interior along its axial direction. Several jet holes are also provided on the drill rod, with their axes angled. Cooling holes are also present on the drill head. When the drill head and outer tube are threaded together, a gap is formed between them. Coolant enters through this gap, with some flowing into the cooling holes and some into the jet holes.

2. The BTA drill bit with a vibration damping structure as described in claim 1, characterized in that, The front end of the drill bit head is conical, and the rear end of the drill bit head is a stepped cylindrical shape. The thread is formed at the rear end of the drill bit head.

3. The BTA drill bit with a shock-absorbing structure as described in claim 2, characterized in that, The stepped cylindrical shape includes a first cylindrical section with a large diameter and a second cylindrical section with a small diameter, and the thread is formed on the second cylindrical section.

4. The BTA drill bit with a shock-absorbing structure as described in claim 3, characterized in that, A guide bar is installed on the first cylindrical section.

5. The BTA drill bit with a vibration damping structure as described in claim 1, characterized in that, The axis of the cooling hole is parallel to the axis of the drill bit.

6. The BTA drill bit with a vibration damping structure as described in claim 1, characterized in that, Two cooling holes are provided, symmetrically arranged with respect to the axis of the drill bit.

7. The BTA drill bit with a vibration damping structure as described in claim 1, characterized in that, The angle between the jet hole and the drill bit axis is 30-60°.

8. The BTA drill bit with a vibration damping structure as described in claim 1, characterized in that, The jet orifice is arranged in multiple rings, with multiple orifices in each ring.

9. The BTA drill bit with a vibration damping structure as described in claim 1, characterized in that, The aforementioned boss is arranged in multiple rings, with multiple bosses in each ring.

10. The method of using the BTA drill bit with a vibration damping structure as described in any one of claims 1-9, characterized in that: The drill bit and outer tube are threaded together, and a gap is formed between the outer tube and the drill rod. After the coolant enters through the gap, part of the coolant flows through the cooling hole to cool the cutting edge on the drill bit. Then, this part of the coolant flows back to the chip removal channel in the middle of the drill bit with the chips, forming an internal cooling and internal chip removal circulation structure. Another part of the coolant is ejected from the jet hole, which then pushes the chips inside the chip removal channel to move towards the tail of the drill rod. During the drilling process, the coolant that enters the chip removal channel through the jet hole flows backward as a whole, reducing the air pressure inside the drill rod. This makes the pressure at the drill bit head greater than the pressure inside the chip removal channel, thereby accelerating the liquid flow. At the same time, the coolant ejected from the jet hole can also effectively clean the hole wall and accelerate the discharge of chips.

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