Fine boring vibration reduction cutter bar

Abstract

The utility model discloses a fine boring vibration reduction cutter bar which comprises a cutter handle, a boring bar, a connecting body and a boring cutter, and the two ends of the connecting body are fixedly connected with the cutter handle and the boring cutter respectively. A first vibration reduction cavity is formed between the boring rod and the cutter handle, a vibration reduction ball is arranged in the first vibration reduction cavity, a second vibration reduction cavity is formed in the connecting body, a vibration reduction block, a first elastic positioning piece and a second elastic positioning piece are arranged in the second vibration reduction cavity, and a rigidity adjusting piece is arranged between the second elastic positioning piece and the boring cutter. A sealing piece is arranged between the rigidity adjusting sheet and the connecting body; the first vibration reduction cavity and the second vibration reduction cavity are used for containing damping oil, a plurality of annular grooves are formed in the outer side surface of the vibration reduction block, friction plates are arranged in the annular grooves, and a plurality of oil passing grooves are formed in the outer side wall of each friction plate. The fine boring vibration reduction cutter bar has the advantages that the vibration reduction balls are arranged in the first vibration reduction cavity, and the friction plates are arranged on the surfaces of the outer sides of the vibration reduction blocks, so that the fine boring vibration reduction cutter bar has better vibration reduction performance during machining.

Description

A precision boring vibration damping tool bar Technical Field

[0001] This utility model relates to the field of precision boring vibration damping tool bar technology, and in particular to a precision boring vibration damping tool bar. Background Technology

[0002] In the deep hole boring process of castings, one of the most critical factors affecting the machining accuracy of mechanical parts is chatter. Chatter suppression technology is a prerequisite for ensuring workpiece machining quality and improving machining efficiency, and is therefore particularly important. Chatter from the boring bar leads to surface texture, insufficient machining accuracy, and severe tool wear. The noise it generates also harms the physical and mental health of the operator.

[0003] Referring to patent CN204747539U, in existing precision boring damping tool holders, a damping block is provided within the hollow rod body. This damping block is radially positioned on the inner wall of the hollow rod body via a first elastic positioning member and a second elastic positioning member, and damping fluid is provided between the damping block and the hollow rod body. However, the existing precision boring damping tool holders lack damping performance in the hollow rod body, and their overall damping effect is poor, requiring improvement. Summary of the Invention

[0004] The purpose of this invention is to propose a precision boring damping tool bar with good vibration reduction performance.

[0005] This utility model proposes a precision boring damping tool holder, including a tool holder, a boring bar, a connecting body, and a boring tool. The boring bar is sleeved and installed around the tool holder. The two ends of the connecting body are respectively connected and fixed to the tool holder and the boring tool. A first damping cavity is formed between the boring bar and the tool holder, and damping balls are disposed in the first damping cavity. A second damping cavity is formed in the connecting body, and a damping block, a first elastic positioning element, and a second elastic positioning element are disposed in the second damping cavity. The first and second elastic positioning elements are disposed at both ends of the damping block. A stiffness adjustment piece is disposed between the second elastic positioning piece and the boring tool. A sealing element is disposed between the stiffness adjustment piece and the connecting body. The first and second damping cavities are used to hold damping oil. Several annular grooves are formed on the outer surface of the damping block, and friction plates are disposed in the annular grooves. Several oil passage grooves for the flow of damping oil are formed on the outer wall of the friction plates.

[0006] Preferably, the damping oil is methyl silicone oil.

[0007] Preferably, both the first and second elastic positioning elements are made of conical rubber, and both ends of the damping block abut against the conical rubber.

[0008] Preferably, a plurality of sealing grooves are formed on the surface of the stiffness adjusting piece, the sealing member is an O-ring, and the O-ring is clamped in the sealing groove to block the gap between the stiffness adjusting piece and the connecting body.

[0009] Preferably, the O-ring is made of rubber material.

[0010] Preferably, the boring tool includes a tool head and a cutting blade. The cutting blade is located at one corner of the tool head. The included angle between the cutting blade and the length direction of the connecting body is set as "a", and 2° < a < 3° is satisfied. The included angle between the cutting blade and the diameter direction of the connecting body is set as "b", and b = ±0.5° is satisfied.

[0011] Preferably, a chip fluting is formed on one side of the tool head near the cutting blade.

[0012] Preferably, a first cooling water hole is formed through the tool shank along its length direction, a second cooling water hole is formed through the connecting body along its length direction, a third cooling water hole is formed in the boring tool, and both ends of the second cooling water hole are respectively connected to the first cooling water hole and the third cooling water hole.

[0013] Preferably, a first filling port and a second filling port are formed on the outer side wall of the connecting body. The first filling port is connected to the first damping cavity, and the second filling port is connected to the second damping cavity.

[0014] As can be seen from the above description of the present invention, the present invention has the following beneficial effects:

[0015] 1. Shock-absorbing balls are installed in the first damping cavity between the tool shank and the boring bar, and a damping block with friction plates is provided in the second damping cavity of the connecting body. Damping oil is filled in both the first damping cavity and the second damping cavity, so that the precision boring damping bar has a good damping effect during processing; and in the first damping cavity, the second-order damping of the precision boring damping bar is satisfied by the collision between the shock-absorbing balls, so that it has a wider damping range.

[0016] 2. The tool head is designed with weight reduction using lightweight alloy. A chip fluting is formed on one side of the tool head near the cutting blade, and the installation angle of the tool head and the cutting blade is optimized according to the cutting blade and cutting parameters, so that when the cutting blade cuts, the cutting force is minimized and the vibration force is reduced. Description of the Drawings

[0017] Figure 1 is a cross-sectional view of a precision boring damping bar in Embodiment 1;

[0018] Figure 2 is a cross-sectional view of the connecting body in the embodiment;

[0019] Figure 3 is a cross-sectional view of the installation of the damping block, the first elastic positioning member and the second elastic positioning member in the embodiment;

[0020] Figure 4 is a cross-sectional view of the vibration damping block in the embodiment;

[0021] Figure 5 is a front view of the friction plate in the embodiment;

[0022] Figure 6 is a magnified view of part B in Figure 2 of the embodiment;

[0023] Figure 7 is a cross-sectional view of the stiffness adjustment piece in the embodiment;

[0024] Figure 8 is a cross-sectional view of the tool holder and boring bar of the embodiment;

[0025] Figure 9 is a magnified view of a portion of point C in Figure 8 of the embodiment;

[0026] Figure 10 is a magnified view of a portion A in Figure 1 of the embodiment;

[0027] Figure 11 is a schematic diagram of the structure of the first cooling water hole in the tool holder of the embodiment;

[0028] Figure 12 is a cross-sectional view of the boring tool in the embodiment;

[0029] Figure 13 is a schematic diagram of the boring tool in the embodiment.

[0030] Reference numerals: 1. Tool holder; 11. First cooling water hole; 2. Boring bar; 21. First damping cavity; 22. Damping ball; 3. Connecting body; 31. Second damping cavity; 32. Damping block; 321. Annular groove; 33. First elastic positioning element; 34. Second elastic positioning element; 35. Stiffness adjustment plate; 351. Sealing groove; 36. Friction plate; 361. Oil groove; 37. Second filling port; 38. First filling port; 39. Second cooling water hole; 4. Boring tool; 41. Tool head; 42. Insert; 43. Chip groove; 44. Third cooling water hole; 5. Seal. Detailed Implementation

[0031] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer and more understandable, the present utility model will be further described in detail below with reference to Figures 1-13 and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0032] Referring to Figure 1, a precision boring vibration damping tool holder includes a tool holder 1, a boring bar 2, a connecting body 3, and a boring tool 4. The boring bar 2 is a hollow tube, and the tool holder 1 is inserted inside it. Both ends of the connecting body 3 are connected and fixed to the tool holder 1 and the boring tool 4, respectively. The connections between the tool holder 1 and the boring bar 2, between the tool holder 1 and the connecting body 3, and between the connecting body 3 and the boring tool 4 are all tight-fitting brazed connections, and the outer diameter is finally ground to form the final shape. A BT tool holder 1 is selected for the tool holder 1, thus providing better installation versatility. Furthermore, the vibration damping tool holder is made of composite material, resulting in high rigidity and strong toughness.

[0033] Referring to Figures 2 and 3, a second vibration damping cavity 31 is formed along the length of the connecting body 3. The second vibration damping cavity 31 is annular, and a vibration damping block 32, a first elastic positioning member 33, and a second elastic positioning member 34 are disposed within the second vibration damping cavity 31. The first elastic positioning member 33 and the second elastic positioning member 34 are respectively installed at both ends of the vibration damping block 32, thereby positioning the vibration damping block 32 within the second vibration damping cavity 31. After positioning and installation, the first elastic positioning member 33 abuts against the end wall within the second vibration damping cavity 31. A stiffness adjustment piece 35 is provided between the second elastic positioning member and the boring bar 4. The stiffness adjustment piece 35 is provided to prevent direct contact between the boring bar 4 and the second elastic positioning member, thereby ensuring that the boring bar 4 remains stably positioned after being installed with the connecting body 3. Both the first elastic positioning element 33 and the second elastic positioning element 34 are set as conical rubber. The conical rubber is made of high-hardness NBR with a Shore hardness of 95 degrees. It has the characteristics of high rigidity and high elasticity, and can effectively deform itself in the vibration reduction system to buffer vibration and transmit force.

[0034] Referring to Figures 4 and 5, to achieve good vibration reduction in the precision boring damping tool holder, several annular grooves 321 are formed along the length of the outer side wall of the damping block 32, and friction plates 36 are disposed within the annular grooves 321. The damping block 32 is made of tungsten steel, thus giving it the characteristics of large mass and good vibration reduction effect. After the damping friction plates 36 are installed on the damping block 32, the high-frequency vibration friction between the friction plates 36 and the side wall of the damping block 32 converts the potential energy of the vibration into heat energy.

[0035] Referring to Figures 2 and 3, to improve the vibration damping effect of the connecting body 3 of the precision boring damping tool holder, a second filling port 37 is formed on the connecting body 3. This second filling port 37 is connected to the second damping cavity 31, and damping oil is poured into the second damping cavity 31 through the second filling port 37. Several oil grooves 361 are formed on the outer wall of the friction plate 36, allowing the damping oil to flow within these grooves after being loaded into the second damping cavity 31. The damping oil, located between the damping block 32, the friction plate 36, and the inner wall of the second damping cavity 31, can convert the vibration generated by the system into heat energy, which is then carried away by the coolant, thus achieving the vibration damping effect. Methyl silicone oil was selected as the damping oil. Methyl silicone oil has excellent damping performance, with a viscosity of 100-1,000,000 centistokes at 25°C. Calculations show its damping range is 1.2-13,000 N·slm, making it suitable for use in the first damping cavity 21. The connector 3 adopts a composite damping design, filling the first damping cavity 21 with methyl silicone oil damping oil and configuring damping blocks 32 with friction plates 36 to improve the damping effect.

[0036] Referring to Figures 2, 6, and 7, a sealing element 5 is provided between the stiffness adjustment plate 35 and the connecting body 3 to achieve a good sealing effect on the damping oil in the second damping cavity 31. For this purpose, several sealing grooves 351 are formed on the surface of the stiffness adjustment plate 35, and the sealing element 5 is set as an O-ring, which is fitted into the sealing groove 351 to seal the gap between the stiffness adjustment plate 35 and the connecting body 3. The O-ring is made of rubber material to provide a better sealing effect on the gap between the stiffness adjustment plate 35 and the connecting body 3.

[0037] Referring to Figures 8, 9, and 10, to further improve the vibration damping performance of the precision boring damping tool holder, a first damping cavity 21 is formed between the boring bar 2 and the tool holder 1, and a first filling port 38 is formed on the outer surface of the connecting body 3, so that the first filling port 38 is connected to the first damping cavity 21. Damping balls 22 and damping oil (not shown in the figures) are poured into the first damping cavity 21 through the first filling port 38. The damping oil poured into the first damping cavity 21 is the same as the damping oil in the second damping cavity 31, both being methyl silicone oil; and the poured damping balls 22 are made of tungsten steel. Through the first damping cavity 21, the damping balls 22 collide with the damping oil to achieve second-order vibration damping of the precision boring damping tool holder, giving the precision boring damping tool holder a wider vibration damping range. The vibration damping structure of this precision boring tool holder consists of a damping block and friction plate 36 within the second damping chamber 31, and the collision of damping balls 22 within the first damping chamber 21, resulting in a length-to-diameter ratio of 20 for the tool holder. This composite vibration damping structure allows for deep hole machining with diameters of 10-20 times the diameter, offering a wider range of applications. The composite vibration damping structure provides excellent vibration reduction during machining, enabling high-speed rough boring and high-precision precision boring of internal holes, and also extends service life.

[0038] Referring to Figures 2, 11, and 12, to maintain a suitable temperature during operation, the precision boring damping tool holder features a first cooling water hole 11 extending along its length in the tool holder 1, a second cooling water hole 39 extending along its length in the connecting body 3, and a third cooling water hole 44 within the boring tool 4. The two ends of the second cooling water hole 39 are connected to the first cooling water hole 11 and the third cooling water hole 44, respectively. Coolant flows from one end of the first cooling water hole 11 into the second cooling water hole 39, and finally into the third cooling water hole 44 and is discharged. This coolant effectively removes the heat generated by system vibration, thus achieving vibration damping.

[0039] Referring to FIGS. 12 and 13, the boring tool 4 includes a tool head 41 and a cutting blade 42. After the tool head 41 is tightly fitted with the connecting body 3, it is fixed by brazing. The cutting blade 42 is disposed at a corner of the end of the tool head 41 away from the connecting body 3. The included angle between the cutting blade 42 and the length direction of the connecting body 3 is set as "a", and it is made to satisfy 2° < a < 3°. And the included angle between the cutting blade 42 and the diameter direction of the connecting body 3 is set as "b", and it is made to satisfy b = ±0.5°. Thus, through the optimized design of the installation angle of the cutting blade 42, when the cutting blade 42 is cutting, the cutting force is minimized and the vibration force can be reduced. The tool head 41 is designed with weight reduction using a lightweight alloy, and a chip pocket 43 is formed by opening on one side of the tool head 41 near the cutting blade 42, so that during the machining process of this fine boring vibration damping tool bar, the waste chips generated can be discharged from the chip pocket 43, thereby not only ensuring smooth chip removal but also being more conducive to vibration damping.

[0040] The specific implementation principle of the embodiment of the present application is as follows: When assembling this fine boring vibration damping tool bar, the vibration damping block 32 equipped with the friction plate 36 is assembled in the second vibration damping cavity 31 of the connecting body 3 through the first elastic positioning member 33 and the second elastic positioning member 34. An O-ring is embedded in the sealing groove 351 of the stiffness adjustment piece 35, and the stiffness adjustment piece 35 is installed at the opening of the second vibration damping cavity 31 and abuts against the second elastic positioning member 34. After the tool head 41 of the boring tool 4 is installed with the connecting body 3, it abuts against the stiffness adjustment piece 35. And damping oil is poured into the second vibration damping cavity 31 from the second pouring port 37, and vibration damping balls 22 and damping oil are poured into the first vibration damping cavity 21 from the first pouring port 38.

[0041] When this fine boring vibration damping tool bar performs high-speed rough boring and high-precision fine boring on the inner hole, the high-frequency vibration friction between the friction plate 36 in the second vibration damping cavity 31 and the side wall of the vibration damping block converts the potential energy of the vibration into heat energy. The damping oil is between the vibration damping block, the friction plate 36 and the second vibration damping cavity, and it can convert the vibration generated by the system into heat energy. And the collision of the vibration damping balls 22 in the first vibration damping cavity 21 performs second-order vibration damping on the fine boring vibration damping tool bar. Coolant is introduced from the first coolant hole 11, and the coolant flows from the first coolant hole 11 to the second coolant hole 39, and finally flows into the third coolant hole 44 and is discharged. Thus, the heat energy generated by the system vibration is taken away by the coolant, so as to achieve the purpose of vibration damping. The length-diameter ratio of this fine boring vibration damping tool bar reaches 20 times, and it has a good vibration damping effect, which can meet the requirements of high-speed rough boring and high-precision fine boring of the inner hole; and it has a longer service life.

[0042] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution to other situations without modification, shall be protected by the present invention.

Claims

1. A precision boring vibration damping tool holder, characterized in that: It includes a tool shank, a boring bar, a connecting body and a boring cutter. The boring bar is sleeved and installed on the periphery of the tool shank. The two ends of the connecting body are respectively connected and fixed to the tool shank and the boring cutter. A first damping cavity is formed between the boring bar and the tool shank, and damping balls are arranged in the first damping cavity. A second damping cavity is formed in the connecting body, and a damping block, a first elastic positioning member and a second elastic positioning member are arranged in the second damping cavity. The first elastic positioning member and the second elastic positioning member are arranged at both ends of the damping block. A stiffness adjustment piece is arranged between the second elastic positioning member and the boring cutter, and a seal is arranged between the stiffness adjustment piece and the connecting body. The first damping cavity and the second damping cavity are used to contain damping oil. A plurality of annular grooves are formed on the outer surface of the damping block, and friction plates are arranged in the annular grooves. A plurality of oil grooves for the damping oil to flow are formed on the outer side wall of the friction plates.

2. The precision boring vibration damping tool holder according to claim 1, characterized in that: The damping oil is selected as methyl silicone oil.

3. The precision boring vibration damping tool holder according to claim 1, characterized in that: Both the first elastic positioning member and the second elastic positioning member are arranged as tapered rubbers, and both ends of the damping block are abutted against the tapered rubbers.

4. A precision boring vibration damping tool holder according to claim 1, characterized in that: A plurality of sealing grooves are formed on the surface of the stiffness adjustment piece. The seal is arranged as an O-ring, and the O-ring is clamped in the sealing grooves to seal the gap between the stiffness adjustment piece and the connecting body.

5. A precision boring vibration damping tool holder according to claim 4, characterized in that: The O-ring is made of rubber material.

6. A precision boring vibration damping tool holder according to claim 1, characterized in that: The boring cutter includes a tool tip and a cutting blade. The cutting blade is located at one corner end of the tool tip. The included angle between the cutting blade and the length direction of the connecting body is set as "a", and 2° < a < 3° is satisfied. The included angle between the cutting blade and the diameter direction of the connecting body is set as "b", and b = ±0.5° is satisfied.

7. A precision boring vibration damping tool holder according to claim 6, characterized in that: A chip fluting is formed on one side of the tool tip near the cutting blade.

8. A precision boring vibration damping tool holder according to claim 1, characterized in that: A first cooling water hole is formed through the tool shank along its length direction. A second cooling water hole is formed through the connecting body along its length direction. A third cooling water hole is formed in the boring cutter. The two ends of the second cooling water hole are respectively connected and communicated with the first cooling water hole and the third cooling water hole.

9. A precision boring vibration damping tool holder according to claim 1, characterized in that: A first filling port and a second filling port are formed on the outer side wall of the connecting body. The first filling port is connected and communicated with the first damping cavity, and the second filling port is connected and communicated with the second damping cavity.

Images