A drill pipe vibration reduction device based on a nonlinear energy sink

Abstract

This invention relates to the field of deep hole machining technology, specifically to a drill pipe vibration damping device based on a nonlinear energy trap. To solve the problem of drill pipe vibration, a drill pipe vibration damping device based on a nonlinear energy trap is provided, comprising a connecting base with connecting ends at both ends. An annular groove, coaxially arranged with the connecting base, is formed in the axial center of the connecting base. Multiple nonlinear energy trap mechanisms are circumferentially distributed within the annular groove. A base plate and a V-shaped connecting plate are arranged vertically. Two elastic side plates, the base plate, and the V-shaped elastic connecting plate form a near-rectangular frame structure. Each of the two opposite side walls of the two elastic side plates has a locking groove. The two ends of a piezoelectric ceramic stack are respectively locked into the locking groove. An energy dissipation circuit is placed within the circuit space. A metal block is fixed to the V-shaped connecting plate. Springs connect the two spring side plates to the annular groove. This invention, based on a nonlinear energy trap, can effectively dissipate energy generated by drill pipe vibration, resulting in a significant vibration damping effect.

Description

Technical Field

[0001] This invention relates to the field of deep hole machining technology, and particularly to the field of drill pipe vibration reduction technology, specifically a drill pipe vibration reduction device based on a nonlinear energy trap. Background Technology

[0002] During deep hole machining, drill rods are prone to chatter. The main causes of drill rod vibration include: when drilling deep holes with a large length-to-diameter ratio, the drill rod is relatively slender, equivalent to a cantilever beam, with weak bending stiffness; imbalance between the weight of the tool holder and the cutting forces between the cutting edges; poor stiffness of the power transmission system; and uneven workpiece material. Drill rod vibration can easily lead to a significant decrease in the machining quality of the workpiece, and in severe cases, it can even cause the workpiece to be scrapped. Therefore, research on drill rod mechanical vibration control methods is particularly important. Summary of the Invention

[0003] In order to solve the problem of drill pipe vibration, this invention provides a drill pipe vibration reduction device based on a nonlinear energy trap.

[0004] This invention is achieved using the following technical solution: A drill pipe vibration damping device based on a nonlinear energy trap includes a solid cylindrical connecting base. Both ends of the connecting base are connecting ends (as is known to those skilled in the art, connecting ends are used to connect the drill bit and the drill pipe, or to connect the front drill pipe and the rear drill pipe). An annular groove, coaxially arranged with the connecting base, is formed in the axial center of the connecting base. Multiple nonlinear energy trap mechanisms are circumferentially distributed within the annular groove. Each nonlinear energy trap mechanism includes a base plate, two elastic side plates arranged side-by-side, a V-shaped elastic connecting plate with its opening facing upwards, a metal block, a piezoelectric ceramic stack, and an energy-dissipating circuit. The base plate and the V-shaped connecting plate are arranged vertically. The side plates, bottom plate, and V-shaped elastic connecting plate form a near-rectangular frame structure. The two elastic side plates have locking grooves on their opposite side walls. The piezoelectric ceramic stack is located within the near-rectangular frame structure, with its two ends respectively locked into the locking grooves. The bottom of the bottom plate has a circuit space and wire holes. The energy-consuming circuit is placed in the circuit space. The piezoelectric ceramic stack extends its wires and connects to the energy-consuming circuit through the wire holes. The metal block is fixed in the middle of the V-shaped connecting plate. The length of the bottom plate is aligned with the width of the annular groove, and the bottom plate is fixed to the bottom wall of the annular groove. Springs connect the outer walls of the two spring side plates to the two side walls of the annular groove.

[0005] Working Principle: The nonlinear energy trap is a passive control technology with significant effects in vibration suppression. It mainly consists of three parts: a relatively light added mass, strong nonlinear stiffness, and damping elements. The nonlinear stiffness provides nonlinear restoring force, giving the nonlinear energy trap a non-constant natural frequency. Therefore, the nonlinear energy trap can achieve instantaneous resonance with the main structure, thereby expanding its vibration reduction bandwidth. The damping elements dissipate the vibration energy absorbed by the nonlinear energy trap from the main structure, ultimately achieving energy dissipation and vibration reduction. The energy transfer mechanism between the nonlinear energy trap and the main structure is targeted energy transfer. This transfer is characterized by high speed and unidirectional (irreversible) characteristics. Therefore, the nonlinear energy trap can efficiently capture the vibration energy of the main structure and transfer it to itself, ultimately dissipating it through the damping elements.

[0006] In this invention, the nonlinear energy trap uses a metal block as added mass, two elastic side plates as strong nonlinear stiffness, and a piezoelectric ceramic stack and its connected energy-dissipating circuit as damping elements. When the drill rod vibrates, the two elastic side plates provide strong nonlinear stiffness in the radial direction, creating multiple nonlinear resonance conditions. When resonance trapping occurs, vibration energy is rapidly transferred from the drill rod to the nonlinear energy trap mechanism. At this time, the elastic side plates deform and act on the piezoelectric ceramic stack. Utilizing the polarization phenomenon of the piezoelectric ceramic stack under tension and compression, equal positive and negative charges are generated, converting vibration energy into electrical energy which is then consumed by the energy-dissipating circuit. When the vibration energy gradually decreases to a certain critical value, the drill rod can no longer be trapped by the next new resonance state. At this point, the drill rod no longer meets the conditions for resonance trapping, so most of the vibration energy is consumed within the nonlinear energy trap mechanism and does not return to the drill rod structure. This reduces the vibration generated by the drill rod during machining, improves the machining quality of the workpiece, and features a simple and compact structure, reasonable design, wide vibration suppression bandwidth, and significant vibration suppression effect.

[0007] Furthermore, the density of the metal block is greater than that of the V-shaped elastic connecting plate, which effectively improves the vibration suppression effect of the nonlinear energy trap mechanism.

[0008] The beneficial effects of this invention are as follows: Based on a nonlinear energy trap, this invention can effectively dissipate the energy generated by drill rod vibration, resulting in significant vibration suppression. The nonlinear stiffness in the nonlinear energy trap ensures internal resonance with the drill rod, achieving excellent vibration suppression capabilities over a wide frequency band. Simultaneously, the nonlinear energy trap can completely transfer the vibration energy generated by the drill rod movement to its own device through target energy transfer, and then the piezoelectric stack converts the vibration energy into electrical energy, which is then consumed through a connected energy-dissipating circuit. This invention is rationally designed, simple in structure, and occupies little space, providing ideas and methods for reducing drill rod vibration and improving workpiece machining quality. Attached Figure Description

[0009] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0010] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram illustrating the vibration reduction principle of the present invention; Figure 2 This is a schematic diagram of the overall structure of the present invention; Figure 3 for Figure 2 A sectional view; Figure 4 A schematic diagram of the overall structure of the nonlinear energy trap mechanism; Figure 5 This is a schematic diagram of the assembly structure of the barrel, spring, and cylinder. Figure 6 This is a schematic diagram of the structure connecting the substrate.

[0012] In the diagram: 1-Connecting base, 2-Nonlinear energy trap mechanism, 21-Base plate, 22-Elastic side plate, 23-V-shaped elastic connecting plate, 24-Metal block, 25-Piezoelectric ceramic stack, 26-Energy dissipation circuit, 27-Card slot, 28-Circuit space, 29-Wire hole, 3-Annular groove, 4-Spring, 5-Barrel body, 6-Cylinder, 7-Boss, 8-Card slot, 9-Threaded hole, 10-Fixing hole, 11-Blind hole, 12-Bolt. Detailed Implementation

[0013] To better understand the above-mentioned objectives, features, and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0014] In this description, it should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. It should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joint" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0015] Many specific details are set forth in the following description in order to provide a full understanding of the invention, but the invention may also be practiced in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the invention, and not all embodiments.

[0016] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0017] like Figure 1 , 2 As shown in Figures 3, 4, and 6, a drill rod vibration damping device based on a nonlinear energy trap includes a solid cylindrical connecting base 1. Both ends of the connecting base 1 are connecting ends (as is known to those skilled in the art, connecting ends are used to connect the drill bit and the drill rod or to connect the front drill rod and the rear drill rod). An annular groove 3, coaxially arranged with the connecting base 1, is opened in the axial center of the connecting base 1. Multiple nonlinear energy trap mechanisms 2 are distributed circumferentially within the annular groove 3. Each nonlinear energy trap mechanism 2 includes a base plate 21, two elastic side plates 22 arranged side by side, a V-shaped elastic connecting plate 23 with its opening facing upward, a metal block 24, a piezoelectric ceramic stack 25, and an energy dissipation circuit 26. The base plate 21 and the V-shaped connecting plate are arranged vertically, and the two elastic side plates 22 are arranged vertically. 2. The base plate 21 and the V-shaped elastic connecting plate 23 form a near-rectangular frame structure. The two elastic side plates 22 are provided with locking grooves 27 on their opposite side walls. The piezoelectric ceramic stack 25 is located in the near-rectangular frame structure and its two ends are respectively locked in the locking grooves 27. The bottom of the base plate 21 is provided with a circuit space 28 and a wire hole 29. The energy-consuming circuit 26 is placed in the circuit space 28. The piezoelectric ceramic stack 25 extends a wire and is connected to the energy-consuming circuit 26 through the wire hole 29. The metal block 24 is fixed in the middle of the V-shaped connecting plate. The length arrangement direction of the base plate 21 is consistent with the width arrangement direction of the annular groove 3 and the base plate 21 is fixed to the bottom wall of the annular groove 3. The outer side walls of the two spring 4 side plates are connected to the two side walls of the annular groove 3.

[0018] Working Principle: The nonlinear energy trap is a passive control technology with significant effects in vibration suppression. It mainly consists of three parts: a relatively light added mass, strong nonlinear stiffness, and damping elements. The nonlinear stiffness provides nonlinear restoring force, giving the nonlinear energy trap a non-constant natural frequency. Therefore, the nonlinear energy trap can achieve instantaneous resonance with the main structure, thereby expanding its vibration reduction bandwidth. The damping elements dissipate the vibration energy absorbed by the nonlinear energy trap from the main structure, ultimately achieving energy dissipation and vibration reduction. The energy transfer mechanism between the nonlinear energy trap and the main structure is targeted energy transfer. This transfer is characterized by high speed and unidirectional (irreversible) characteristics. Therefore, the nonlinear energy trap can efficiently capture the vibration energy of the main structure and transfer it to itself, ultimately dissipating it through the damping elements.

[0019] In the nonlinear energy trap of this invention, the metal block 24 is an added mass, the two elastic side plates 22 provide strong nonlinear stiffness, and the damping element is a piezoelectric ceramic stack 25 and an energy-dissipating circuit 26 connected to it. When the drill rod vibrates, due to the strong nonlinear stiffness provided by the two elastic side plates 22 in the radial direction, multiple nonlinear energy trap mechanisms 2 form multiple nonlinear resonance conditions. When resonance trapping occurs, the vibration energy is rapidly transferred from the drill rod to the nonlinear energy trap mechanism 2. At this time, the elastic side plates 22 deform and act on the piezoelectric ceramic stack 25. Utilizing the polarization phenomenon of the piezoelectric ceramic stack 25 during tension and compression, equal positive and negative charges are generated, causing the vibration energy to be converted into electrical energy and consumed by the energy-dissipating circuit 26. When the vibration energy gradually decreases to a certain critical value, the drill rod can no longer be captured by the next new resonance state. At this time, the drill rod no longer meets the conditions for resonance capture. Therefore, most of the vibration energy will be consumed in the nonlinear energy trap mechanism 2 and will not return to the drill rod structure. This reduces the vibration generated by the drill rod in machining, improves the machining quality of the workpiece, and has a simple and compact structure, reasonable design, wide vibration suppression bandwidth, and significant vibration suppression effect.

[0020] In practice, the density of the metal block 24 is greater than that of the V-shaped elastic connecting plate 23, which effectively improves the vibration suppression effect of the nonlinear energy trap mechanism 2.

[0021] In specific implementation, such as Figure 5 As shown, the device also includes two barrels 5 and two cylinders 6. Two springs 4 are located inside the two barrels 5 respectively. One end of each spring 4 is fixed to the inner bottom surface of the bottom of the two barrels 5. The outer bottom surface of the bottom of the two barrels 5 is fixed to the outer side wall of the side plate of each spring 4. The ends of the two springs 4 that are not connected to the barrels 5 are coaxially fixed to one end of each cylinder 6. The diameter of the two cylinders 6 is smaller than the inner diameter of the sleeve. Blind holes 11 that are adapted to the two sleeves (clearance fit) are provided on both sides of the annular groove 3. The structure is more stable and the vibration reduction effect is better.

[0022] In specific implementation, multiple slots 8 are evenly distributed around the bottom of the annular groove 3. The bottom of multiple near rectangular frame structure base plates 21 is provided with protrusions 7 that are adapted to the slots 8. The circuit space 28 is located at the bottom of the protrusions 7. The protrusions 7 are fixed in the corresponding slots 8. This structure is more compact and can better transmit the vibration energy of the drill rod to the piezoelectric ceramic stack 25 and then consume it through the energy dissipation circuit 26.

[0023] In practice, the bottom of the slot 8 is provided with a threaded hole 9, and the boss 7 is provided with a fixing hole 10 that matches the threaded hole 9. The bolt 12 passes through the fixing hole 10 and is screwed into the threaded hole 9 to fix the bottom plate 21 of the near rectangular frame structure to the bottom wall of the annular groove 3. The structure is specific and standardized, which makes it easier to absorb and consume the vibration energy generated by the drill rod.

[0024] In this specific embodiment, one of the connecting ends of the connecting base 1 is provided with an internal thread, and the other connecting end is provided with an external thread, thus specifying and standardizing the structure.

[0025] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the present invention. Although detailed descriptions have been provided with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments, and they should all be covered within the protection scope of the claims.

Claims

1. A drill pipe vibration reduction device based on a nonlinear energy trap, characterized in that, The system includes a solid columnar connecting base (1), with both ends of the connecting base (1) serving as connecting ends. An annular groove (3) coaxially arranged with the connecting base (1) is opened in the axial center of the connecting base (1). Multiple nonlinear energy trap mechanisms (2) are distributed circumferentially within the annular groove (3). Each nonlinear energy trap mechanism (2) includes a base plate (21), two elastic side plates (22) arranged side-by-side, a V-shaped elastic connecting plate (23) with its opening facing upwards, a metal block (24), a piezoelectric ceramic stack (25), and an energy-consuming circuit (26). The base plate (21) and the V-shaped connecting plate are arranged vertically. The two elastic side plates (22), the base plate (21), and the V-shaped elastic connecting plate (23) form a nearly rectangular frame structure. The two elastic side plates (22)... 2) Each of the two opposing side walls is provided with a locking groove (27). The piezoelectric ceramic stack (25) is located in the near rectangular frame structure and its two ends are respectively locked in the locking groove (27). The bottom of the base plate (21) is provided with a circuit space (28) and a wire hole (29). The energy-consuming circuit (26) is placed in the circuit space (28). The piezoelectric ceramic stack (25) extends a wire and is connected to the energy-consuming circuit (26) through the wire hole (29). The metal block (24) is fixed in the middle of the V-shaped connecting plate. The length arrangement direction of the base plate (21) is consistent with the width arrangement direction of the annular groove (3) and the base plate (21) is fixed to the bottom wall of the annular groove (3). The outer side walls of the two elastic side plates (22) are connected to the two side walls of the annular groove (3) by springs (4).

2. The drill pipe vibration reduction device based on a nonlinear energy trap according to claim 1, characterized in that, The density of the metal block (24) is greater than that of the V-shaped elastic connecting plate (23).

3. The drill pipe vibration reduction device based on a nonlinear energy trap according to claim 2, characterized in that, The device also includes two barrels (5) and two cylinders (6). Two springs (4) are located inside the two barrels (5). One end of the two springs (4) is fixed to the inner bottom surface of the bottom of the two barrels (5). The outer bottom surface of the bottom of the two barrels (5) is fixed to the outer side wall of the two elastic side plates (22). The end of the two springs (4) that is not connected to the barrel (5) is coaxially fixed to one end of the two cylinders (6). The diameter of the two cylinders (6) is smaller than the inner diameter of the barrels (5). Blind holes (11) that are compatible with the two barrels (5) are provided on both sides of the annular groove (3).

4. The drill pipe vibration reduction device based on a nonlinear energy trap according to claim 3, characterized in that, The bottom of the annular groove (3) is evenly distributed with multiple slots (8). The bottom of multiple near rectangular frame structure base plates (21) is provided with bosses (7) that are compatible with the slots (8). The circuit space (28) is located at the bottom of the bosses (7), and the bosses (7) are fixed in the corresponding slots (8).

5. A drill pipe vibration reduction device based on a nonlinear energy trap according to claim 4, characterized in that, The bottom of the slot (8) is provided with a threaded hole (9), and the boss (7) has a fixing hole (10) that matches the threaded hole (9). The bolt (12) passes through the fixing hole (10) and is screwed into the threaded hole (9) to fix the bottom plate (21) of the near rectangular frame structure to the bottom wall of the annular groove (3).

6. A drill pipe vibration reduction device based on a nonlinear energy trap according to claim 5, characterized in that, One of the connecting ends of the connecting base (1) is provided with an internal thread, and the other connecting end is provided with an external thread.

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