A bidirectional piezoelectric ceramic variable stiffness, memory metal spring variable mass vibration damping boring bar

Abstract

The present invention discloses a bidirectional piezoelectric ceramic variable stiffness, memory metal spring variable mass vibration damping boring bar, which belongs to the field of metal cutting processing technology and includes a variable stiffness module and a variable mass module. The variable stiffness module includes a variable stiffness cantilever beam, and the interior of the variable stiffness cantilever beam is composed of a bidirectional piezoelectric ceramic, a first support block and a second support block. The variable mass module includes an open hollow cylinder, and a closed cavity is provided in the open hollow cylinder. The closed cavity is provided with a memory metal spring, a heating rod and a displacement sensor. The closed cavity is composed of the inner wall on the left side of the open hollow cylinder and the slider on the right side and EPDM rubber. The slider is symmetrically provided with a one-way valve with different flow directions. The present invention adopts the above-mentioned bidirectional piezoelectric ceramic variable stiffness, memory metal spring variable mass vibration damping boring bar to solve the problem of part processing size deterioration due to vibration during the boring process, improve the quality of part processing, and reduce errors.

Description

Technical Field

[0001] The invention relates to the technical field of metal cutting, in particular to a bidirectional piezoelectric ceramic variable stiffness and memory metal spring variable mass vibration damping boring bar. Background Art

[0002] In metal cutting, internal hole machining accounts for approximately 33% of all machining operations. Boring bars are widely used in deep hole machining. However, due to the low rigidity of the boring bar's cantilever beam structure, vibration often occurs when the length-to-diameter ratio of the boring bar is large. Furthermore, during the boring process, since the boring bar needs to extend into the workpiece for machining, the closed working conditions prevent direct observation of the boring bar's real-time machining status. The contact between the boring bar and the workpiece is complex due to vibration, cutting heat, and cutting forces. Poor machining conditions of the boring bar can damage the workpiece's surface quality, affecting the workpiece's dimensional accuracy and the boring machine's machining efficiency. Summary of the Invention

[0003] The purpose of the present invention is to provide a bidirectional piezoelectric ceramic variable stiffness, memory metal spring variable mass vibration damping boring bar, which solves the problem of part processing size deterioration due to vibration during the boring process, improves the quality of part processing and reduces errors.

[0004] To achieve the above-mentioned objectives, the present invention provides a bidirectional piezoelectric ceramic variable stiffness, memory metal spring variable mass vibration damping boring bar, comprising a variable stiffness module and a variable mass module, the variable stiffness module comprising a variable stiffness cantilever beam, the interior of the variable stiffness cantilever beam being composed of a bidirectional piezoelectric ceramic, a first support block and a second support block, one side of the variable stiffness module being connected to the variable mass module, the variable mass module comprising an open hollow cylinder, a closed cavity being provided in the open hollow cylinder, a memory metal spring, a heating rod and a micro displacement sensor being provided in the closed cavity, the closed cavity being composed of the inner wall on the left side of the open hollow cylinder and a slider on the right side and EPDM rubber, the slider being symmetrically provided with one-way valves with different flow directions up and down, and the boring bar cavity being filled with damping fluid.

[0005] Preferably, the outer left side of the variable stiffness cantilever beam is gap-matched with the boring bar cavity, and the right side of the variable stiffness cantilever beam is fixedly connected to the open hollow cylinder.

[0006] Preferably, the first support block is used to support the bidirectional piezoelectric ceramic and provide the rigidity of the boring bar in the left-right direction, and the second support block is used to provide the rigidity of the boring bar in the up-down direction.

[0007] Preferably, the left and right sides of the EPDM rubber are respectively fixedly connected to the inner wall of the open hollow cylinder and the left side of the slider.

[0008] Preferably, the number of the memory metal springs is four, the heating rods are placed inside the memory metal springs, and the number of the heating rods is eight, four on the left and four on the right.

[0009] Preferably, the left and right sides of the memory metal spring are respectively fixedly connected to the inner wall of the open hollow cylinder and the left side of the slider, and the heating rods on the left and right sides are respectively fixedly connected to the inner wall of the open hollow cylinder and the left side of the slider.

[0010] Preferably, the left end of the micro displacement sensor is fixedly connected to the open hollow cylinder, and the right end of the micro displacement sensor is fixed to the slider via two top nuts.

[0011] Preferably, the slider is threadedly connected to the brake assembly on its right side, and the brake assembly is controlled to stop by observing the displayed value of the micro displacement sensor when the slider moves.

[0012] Therefore, the present invention adopts the above-mentioned bidirectional piezoelectric ceramic variable stiffness and memory metal spring variable mass vibration damping boring bar, and changes the overall stiffness of the variable stiffness cantilever beam through bidirectional piezoelectric ceramics; by heating the heating rod, the length of the spring is changed, the slider is moved, and then the content of the damping fluid in the closed cavity is changed, thereby realizing the mass change of the variable mass module.

[0013] By changing the stiffness and mass, the purpose of reducing the vibration of the boring bar is achieved, which solves the problem of deterioration of the part processing size due to vibration during the boring process, improves the quality of part processing and reduces errors.

[0014] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of an embodiment of a bidirectional piezoelectric ceramic variable stiffness and memory metal spring variable mass vibration damping boring bar of the present invention;

[0016] Figure 2 yes Figure 1 Enlarged view of the variable stiffness cantilever beam in;

[0017] Figure 3 This is a schematic structural diagram of a single variable stiffness module of an embodiment of a bidirectional piezoelectric ceramic variable stiffness, memory metal spring variable mass vibration damping boring bar of the present invention; Figure 3 (a) is the front view of a single variable stiffness module; Figure 3 (b) is a three-dimensional diagram of a single variable stiffness module;

[0018] Figure 4 (b) is the side view of the variable stiffness cantilever beam; Figure 4 (a) in the Figure 4(b) Cross-sectional view at AA;

[0019] Figure 5 yes Figure 1 Enlarged view of point A in the middle;

[0020] Figure 6 This is a schematic diagram of the state of the variable mass module when the heating rod is heated in an embodiment of a bidirectional piezoelectric ceramic variable stiffness and memory metal spring variable mass vibration damping boring bar of the present invention;

[0021] Figure 7 This is a schematic diagram of the state of the variable mass module of an embodiment of a bidirectional piezoelectric ceramic variable stiffness and memory metal spring variable mass vibration damping boring bar of the present invention when the heating rod is not heated;

[0022] Figure 8 This is an overall structural diagram of a variable stiffness module and a variable mass module of an embodiment of a bidirectional piezoelectric ceramic variable stiffness and memory metal spring variable mass vibration damping boring bar of the present invention;

[0023] Figure 9 The present invention is a front view of a slider of an embodiment of a bidirectional piezoelectric ceramic variable stiffness and memory metal spring variable mass vibration damping boring bar.

[0024] Reference numerals

[0025] 1. Cutter head; 2. Cutter head connector; 3. Boring bar; 4. Variable stiffness cantilever beam; 5. Open hollow cylinder; 6. EPDM rubber; 7. Memory metal spring; 8. Heating rod; 9. Slider; 10. Micro displacement sensor; 11. Brake assembly; 12. One-way valve; 13. Top nut; 14. Closed cavity; 15. Wire; 16. First support block; 17. Second support block; 18. Bidirectional piezoelectric ceramic; 19. Screw; 20. Brake pad; 21. Electromagnet; 22. Mounting hole; 23. Boring bar cavity. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0027] Unless otherwise defined, the technical or scientific terms used in the present invention shall have the usual meanings understood by persons of ordinary skill in the field to which the present invention belongs. The words "first", "second" and similar terms used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects preceding the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0028] Example 1

[0029] like Figure 1 、 Figure 8 As shown, the present invention provides a bidirectional piezoelectric ceramic variable stiffness, memory metal spring variable mass vibration damping boring bar, comprising a variable stiffness module and a variable mass module. A tool head 1 is connected to a boring bar 3 via a tool head connector 2. The variable stiffness module includes a variable stiffness cantilever beam 4, the left exterior of which is gap-fitted with the cavity of the boring bar 3.

[0030] The variable stiffness cantilever beam 4 is internally composed of a bidirectional piezoelectric ceramic 18, a first support block 16 and a second support block 17. The first support block 16 is used to support the bidirectional piezoelectric ceramic 18 and provide stiffness in the left and right directions of the boring bar 3, and the second support block 17 is used to provide stiffness in the up and down directions of the boring bar 3. Figure 1 The enlarged picture of the variable stiffness cantilever beam 4 is as follows Figure 2 The side view and cross-sectional view of the variable stiffness cantilever beam 4 are shown in FIG. Figure 4 Wherein B is the wall thickness of the variable stiffness cantilever beam 4.

[0031] A single variable stiffness module is formed by the two first support blocks 16 and a bidirectional piezoelectric ceramic 18. Figure 3 As shown, the stiffness of the variable-stiffness cantilever beam 4 is varied by means of the bidirectional piezoelectric ceramic 18. By applying power to the bidirectional piezoelectric ceramic 18 via the conductor 15, the bidirectional piezoelectric ceramic 18 stretches or compresses, thereby varying the stiffness of the variable-stiffness cantilever beam 4. When the voltage applied to the bidirectional piezoelectric ceramic 18 is in the direction of extension, the overall stiffness of the variable-stiffness cantilever beam 4 increases; when the voltage applied is in the direction of compression, the overall stiffness of the variable-stiffness cantilever beam 4 decreases. Thus, by varying the stiffness of the boring bar 3, vibration reduction can be achieved.

[0032] The variable mass module includes an open hollow cylinder 5, in which a closed cavity 14 is provided. The closed cavity 14 is composed of the inner wall on the left side of the open hollow cylinder 5, the slider 9 on the right side, and the EPDM rubber 6. The left and right sides of the EPDM rubber 6 are respectively fixed to the inner wall of the open hollow cylinder 5 and the left side of the slider 9.

[0033] EPDM rubber 6 has good aging resistance and weather resistance and is mostly used to manufacture closed parts. By using adhesive to connect EPDM rubber 6 to the inner wall of the open hollow cylinder 5 and the slider 9 on the right side, a closed cavity 14 is formed.

[0034] The slider 9 includes two one-way valves 12 symmetrically arranged in the upper and lower parts and with different flow directions. The front view of the slider 9 is shown as follows: Figure 9 As shown, the slider 9 is provided with a mounting hole 22 for mounting the one-way valve 12 .

[0035] The boring bar cavity 23 is filled with a damping fluid of a certain density. The damping fluid enters and exits the closed cavity 14 through the one-way valve 12 . The change in mass is mainly achieved by increasing and decreasing the mass of the damping fluid in the closed cavity 14 . Figure 5 A one-way valve 12 on the upper side of the slider 9 is shown in the figure. The upper one-way valve 12 allows the damping fluid to flow from right to left, and the lower one-way valve 12 allows the damping fluid to flow from left to right.

[0036] Slider 9 is threadedly connected to brake assembly 11 on its right side. Slider 9, except for its lower end, has three threaded holes, which are used to connect it to brake assembly 11 via screws 19. Brake assembly 11 includes brake pads 20 and electromagnets 21. The two electromagnets 21 at the lower end pull the brake pads 20 closer to the outer shell of the open hollow cylinder 5, and the friction between the brake pads 20 and the outer shell of the open hollow cylinder 5 causes the vehicle to stop.

[0037] Enclosed cavity 14 contains a micro-displacement sensor 10, four memory metal springs 7, and eight heating rods 8 associated with the memory metal springs 7. Heating the heating rods 8 changes the length of the memory metal springs 7. The heating rods 8 are placed inside the memory metal springs 7. The left and right sides of the memory metal springs 7 are fixedly connected to the inner wall of the open hollow cylinder 5 and the left side of the slider 9, respectively. The left and right heating rods 8 are also fixedly connected to the inner wall of the open hollow cylinder 5 and the left side of the slider 9, respectively. One side of the heating rods 8 is connected to a wire 15, which controls whether the heating rods 8 are heated or not.

[0038] The left end of the micro-displacement sensor 10 is fixedly connected to the enclosed cavity 14, while the right end of the micro-displacement sensor 10 is secured to the slider 9 via two counter-nuts 13. The micro-displacement sensor 10 accurately senses the displacement of the slider 9. When the displacement signal transmitted by the micro-displacement sensor 10 reaches the desired displacement, the electromagnet 21 is energized to brake the slider 9, thereby precisely controlling the movement distance of the slider 9.

[0039] When the heating rod 8 is heated, the memory metal spring 7 is extended due to the heat, driving the right slider 9 to slide to the right. At this time, the damping fluid will give the one-way valve 12 a leftward thrust. Due to the different structures of the one-way valves 12, the upper one-way valve 12 will form an open state, while the lower one-way valve 12 is still in a closed state, so that the damping fluid in the boring bar cavity 23 flows into the closed cavity 14 through the upper one-way valve 12, and the mass in the closed cavity 14 increases. Figure 6 shown.

[0040] When the heating rod 8 is not heated and allowed to cool, the memory metal spring 7 will gradually shrink to its original shape, driving the slider 9 to move to the left, so that the closed cavity 14 will give the one-way valve 12 a rightward thrust. Due to the structural design of the one-way valve 12, the upper one-way valve 12 is in a closed state, and the lower one-way valve 12 is in an open state, so that the damping fluid in the closed cavity 14 flows out of the closed cavity 14 through the lower one-way valve 12, and the mass in the closed cavity 14 is reduced. Figure 7 shown.

[0041] During the process of mass increase or decrease in the closed cavity 14, the displacement of the slider 9 can be monitored at any time by the micro displacement sensor 10. The mass increase or decrease can be calculated based on the distance. When the optimal displacement is reached, the electromagnet 21 of the brake assembly 11 can be energized to achieve a timely braking. In this way, the vibration of the boring bar 3 is reduced by the change in mass.

[0042] Therefore, the present invention adopts the above-mentioned bidirectional piezoelectric ceramic variable stiffness and memory metal spring variable mass vibration damping boring bar to solve the problem of part processing size deterioration due to vibration during the boring process, improve the quality of part processing and reduce errors.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A bidirectional piezoelectric ceramic variable stiffness, memory metal spring variable mass vibration damping boring bar, characterized by: It includes a variable stiffness module and a variable mass module. The variable stiffness module includes a variable stiffness cantilever beam. The variable stiffness cantilever beam is composed of a bidirectional piezoelectric ceramic, a first support block and a second support block. The first support block is used to support the bidirectional piezoelectric ceramic and provide the left-right stiffness of the boring bar. The second support block is used to provide the up-down stiffness of the boring bar. One side of the variable stiffness module is connected to the variable mass module, which includes an open hollow cylinder with a closed cavity inside. A memory metal spring, a heating rod and a micro displacement sensor are provided in the closed cavity. The closed cavity is composed of the inner wall on the left side of the open hollow cylinder, the slider on the right side and EPDM rubber. One-way valves with different flow directions are symmetrically arranged in the upper and lower parts of the slider, and the boring bar cavity is filled with damping fluid.

2. The bidirectional piezoelectric ceramic variable stiffness, memory metal spring variable mass vibration damping boring bar according to claim 1, characterized in that: The left side of the variable stiffness cantilever beam is clearance-matched with the boring bar cavity, and the right side of the variable stiffness cantilever beam is fixedly connected with the open hollow cylinder.

3. The bidirectional piezoelectric ceramic variable stiffness, memory metal spring variable mass vibration damping boring bar according to claim 1, characterized in that: The left and right sides of the EPDM rubber are respectively fixedly connected to the inner wall of the open hollow cylinder and the left side of the slider.

4. The bidirectional piezoelectric ceramic variable stiffness, memory metal spring variable mass vibration damping boring bar according to claim 1, characterized in that: There are four memory metal springs, and the heating rods are placed inside the memory metal springs. There are eight heating rods, four on the left and four on the right.

5. The bidirectional piezoelectric ceramic variable stiffness, memory metal spring variable mass vibration damping boring bar according to claim 4, characterized in that: The left and right sides of the memory metal spring are respectively fixedly connected to the inner wall of the open hollow cylinder and the left side of the slider, and the heating rods on the left and right sides are respectively fixedly connected to the inner wall of the open hollow cylinder and the left side of the slider.

6. The bidirectional piezoelectric ceramic variable stiffness, memory metal spring variable mass vibration damping boring bar according to claim 5, characterized in that: The left end of the micro displacement sensor is fixedly connected to the open hollow cylinder, and the right end of the micro displacement sensor is fixed to the slider via two top nuts.

7. The bidirectional piezoelectric ceramic variable stiffness, memory metal spring variable mass vibration damping boring bar according to claim 6, characterized in that: The slider is threadedly connected to the brake assembly on the right side thereof, and the brake assembly is controlled to stop by observing the displayed value of the micro displacement sensor when the slider moves.

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