Amplitude-adjustable mechanical low-frequency vibration generation device

Abstract

The invention belongs to the field of processing equipment, and provides a mechanical low-frequency vibration generation device with adjustable amplitude. The device is mainly composed of an outer-layer stator and an inner-layer rotor, the stator structure comprises two wave rings, sine wave surfaces are arranged on the wave rings, a retainer in the rotor structure drives cylindrical rollers to roll on the two sine wave surfaces respectively, and by controlling sliding of an adjusting pin in a sliding way of a shell, when it is guaranteed that the rollers are in the same phase, the cylindrical rollers are driven to roll on the two sine wave surfaces respectively. The amplitude of axial vibration can be changed by adjusting the phase difference of sine wave surfaces of the two wave rings, the device can be integrated on a main shaft of portable automatic drilling equipment, axial low-frequency vibration is overlaid while the main shaft conducts feeding motion, discontinuous cutting is achieved, and metal cuttings can be effectively broken. And meanwhile, the vibration amplitude can be changed in the drilling process so as to meet various machining requirements.

Description

Technical Field

[0001] The invention belongs to the field of processing equipment and relates to a mechanical low-frequency vibration generating device with adjustable amplitude. Background Art

[0002] High-end aerospace equipment makes extensive use of lightweight, high-strength carbon fiber reinforced composite materials. To ensure stable load-bearing at key connection points, metal materials such as high-strength titanium alloys and high-strength steel that are resistant to alternating loads are also used. This results in a large number of composite and metal laminated structures, requiring high-quality, high-precision hole making to meet the requirements of high-reliability assembly and safe service. High-strength metals such as titanium alloys and stainless steel are typically difficult to machine and are often processed using low-frequency vibration-assisted drilling. Different metal materials and processing parameters require different vibration amplitudes. When using low-frequency vibration-assisted drilling for carbon fiber composites, the additional vibration can easily cause delamination damage at the exit and entrance. Taking the drilling of composite and titanium alloy laminated structures as an example, auxiliary vibration is required when machining metal and the amplitude of the auxiliary vibration is reduced when machining composite materials. This ensures that both materials achieve the best quality. Therefore, the amplitude of the auxiliary vibration needs to be controlled during the machining process.

[0003] The French company MITIS invented a "Bearing with an axially movable ring and machining apparatus equipped with such a bearing," patented ZL200780029856.X. This structure employs a wave-shaped bearing raceway for the machine tool shank to generate axial periodic reciprocating motion during spindle rotation, causing the tool to generate axial low-frequency vibrations with adjustable amplitude. However, the amplitude cannot be adjusted during machining and its bulkiness precludes its application in assembly sites. Jiao Feng et al. from Henan Polytechnic University invented a "Mechanical Axial Low-Frequency Drilling Device," patented ZL201811303077.0. This device superimposes low-frequency vibrations axially through sinusoidal grooves in a sleeve. The amplitude can be varied by changing the grooves, allowing switching between zero-amplitude and non-zero-amplitude grooves. However, this method imposes low-frequency vibrations on the workpiece, making it difficult to use with large workpieces and presents certain limitations. Zhao Dezhong, Liu Hui and others from Xi'an Petroleum University invented an adjustable-amplitude low-frequency axial vibration drilling device with patent number: CN201911031817.4. Two raceways with sinusoidal fluctuations and balls are integrated into the tool holder and connected through splines. It can be used for machine tool processing of metal parts, but its overall size is large and cannot be integrated into workers' handheld equipment, making it difficult to apply to the processing at the aviation equipment assembly site.

[0004] In summary, in order to meet the requirements of adjustable amplitude of vibration-assisted process for integrated high-quality hole making of laminated structures composed of composite materials and high-strength metal materials, it is necessary to invent a low-frequency vibration generating device with miniaturization, high degree of integration, good reliability and adjustable amplitude to solve the problems of poor processing quality, low precision and severe tool wear in the hole making of laminated structures composed of high-strength metal materials and carbon fiber reinforced composite materials. Summary of the Invention

[0005] To overcome the shortcomings of the existing technology, the present invention invents a mechanical low-frequency vibration generator with adjustable amplitude. The device is equipped with two vibration-generating raceways with sinusoidal surfaces. A cage linkage ring ensures that the rollers on the two raceways are in phase with each other. Adjusting pins are used to adjust the phase of the two raceways, achieving precise adjustment of the total output amplitude. This device can change the low-frequency vibration amplitude during the integrated hole-making and drilling process of a laminated structure composed of composite materials and high-strength metal materials, effectively improving the processing quality. Furthermore, the device can also be used in other scenarios requiring vibration generation and amplitude conditions.

[0006] The technical solution of the present invention:

[0007] A mechanical low-frequency vibration generating device with adjustable amplitude includes a bolt 1, a disc spring 2, a lower connecting block 3, a sealing ring A4, a flat raceway A5, a small retaining ball A6, a retaining frame A7, a roller A8, an adjusting pin 9, an amplitude adjusting ring 10, a wave ring A11, a retaining frame linkage ring 12, a housing 13, a wave ring B14, a roller B15, a retaining frame B16, a small retaining ball B17, a flat raceway B18, a key 19, a sealing ring B20, and an upper connecting block 21.

[0008] The bolt 1 passes through the disc spring sheet 2, the lower connecting block 3 and the upper connecting block 21 in sequence; the cross-section of the lower connecting block 3 is a T-shaped structure, and the lower connecting block 3 includes a base and a cylindrical boss; a semicircular keyway 3a is provided on the cylindrical boss of the lower connecting block 3, and the cylindrical boss of the lower connecting block 3 passes through the plane raceway A5, the retainer A7, the wave ring A11, the retainer linkage ring 12, the wave ring B14, the retainer B16, the plane raceway B18 and is connected to the upper connecting block 21 through the key 19 in sequence; a circular groove 3d is provided on the upper part of the lower connecting block 3 for installing the sealing ring A4; two grooves 3b are provided on the cylindrical boss of the lower connecting block 3, and the plane raceway A5 and the plane raceway B18 correspond to the small ball A6 and the small ball B17 respectively through the positioning The two grooves 3b of the lower connecting block 3 are inserted into the two grooves, and further connected with the grooves on the plane raceway A5 and the plane raceway B18, so as to ensure that the lower connecting block 3 rotates synchronously with the plane raceway A5 and the plane raceway B18; the surface where the base of the upper connecting block 3 meets the cylindrical boss is a stepped surface 3c, and the plane raceway A5 is in close contact with the stepped surface 3c of the upper connecting block 3; the roller A8 is fixed on the retainer A7 to form a thrust bearing, and the retainer A7 is provided with an arc groove for connecting the retainer linkage ring 12, and the roller A8 is in close contact with the plane raceway A5; the adjusting pin 9 is installed on the amplitude adjusting ring 10 and the wave ring A11, and has an interference fit with the amplitude adjusting ring 10 and the wave ring A11 to limit the relative rotation of the amplitude adjusting ring 10 and the wave ring A11; the amplitude adjusting ring A hole is provided on 10 for installing the adjusting pin 9; the left side of the wave ring A11 is a sinusoidal wave surface, and the right side is a plane. The sinusoidal wave surface side of the wave ring A11 is tightly attached to the roller A8, and the plane side of the wave ring A11 is tightly attached to the plane side of the wave ring B14. A hole is provided on the outer circumference of the wave ring A11, which is interference fit with the adjusting pin 9; the two ends of the retainer linkage ring 12 are respectively inserted into the arc grooves of the retainer A7 and the retainer B16 to ensure that the roller A8 and the roller B15 rotate synchronously, thereby ensuring that the roller A8 and the roller B15 are in the same phase; the shell 13 is clearance-matched with the amplitude adjustment ring 10, and the shell 13 is provided with a slideway 13b, which is clearance-matched with the adjusting pin 9, and the adjusting pin 9 can slide on the slideway 13b, and the shell 13 A protrusion 13a is provided on the outer surface to limit the rotation of the housing 13 during operation; the left side of the wave ring B14 is a plane, and the right side is a sinusoidal wave surface. The plane side of the wave ring B14 is in close contact with the plane side of the wave ring A11, and the sinusoidal wave surface side of the wave ring B14 is in close contact with the roller B15; the roller B15 is fixed on the retaining frame B16 to form a thrust bearing, and the roller B15 is in close contact with the wave ring B14 and the plane raceway B18. The retaining frame B16 is provided with an arc groove for connecting the retaining frame linkage ring 12; the cross-section of the upper connecting block 21 is stepped, and a sealing ring B20 is installed on the end face of one end for sealing; the key 19 is installed in the cylindrical keyway of the upper connecting block 21 to limit the relative rotation of the lower connecting block 3 and the upper connecting block 21.

[0009] An axial low-frequency vibration is achieved by superposition of the axial vibrations generated by the rolling of the rollers A8 and B15 on the wave rings A11 and B14 respectively. The wave rings A11 and B14 contain the same number of sinusoidal curve periods and the same amplitude.

[0010] The cage A7 and the cage B16 are provided with a plurality of arc grooves for connecting the cage linkage ring 12 to ensure synchronous rotation of the roller A8 and the roller B15 and ensure that the roller A8 and the roller B15 are in the same phase.

[0011] 2. The amplitude-adjustable mechanical low-frequency vibration generating device according to claim 1 is characterized in that by controlling the sliding of the adjusting pin 9 in the slideway 13b of the housing 13, the phase difference between the sinusoidal surfaces of the wave ring A11 and the wave ring B14 can be adjusted to thereby change the amplitude of the axial vibration.

[0012] The beneficial effect of the present invention is that it provides a mechanical low-frequency vibration generating device with adjustable amplitude. By superimposing the axial vibrations generated by the rolling of rollers A8 and rollers B15 on wave rings A11 and wave rings B14 respectively, an axial low-frequency vibration is superimposed while the tool is performing a feed motion. When drilling a laminated structure composed of composite materials and high-strength metal materials, by controlling the sliding of the adjusting pin 9 in the slideway 13b of the outer shell 13, the phase difference of the sinusoidal surfaces of the two wave rings is adjusted to thereby change the amplitude of the axial vibration. This can more effectively reduce the damage to the composite hole wall caused by metal chip breaking, thereby improving the processing quality and reducing tool wear. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is an exploded schematic diagram of the low-frequency vibrator with adjustable amplitude according to the present invention;

[0014] Figure 2 A cross-sectional view of an assembly of a low-frequency vibrator with adjustable amplitude according to the present invention;

[0015] Figure 3 Schematic diagram of the structure of the lower connecting block in the present invention;

[0016] Figure 4 It is a structural schematic diagram of the shell in the present invention.

[0017] In the figure: 1 bolt, 2 disc spring leaf, 3 lower connecting block, 4 sealing ring A, 5 flat raceway A, 6 small ball bearing A, 7 cage A, 8 roller A, 9 adjusting pin, 10 amplitude adjusting ring, 11 wave ring A, 12 cage linkage ring, 13 housing, 14 wave ring B, 15 roller B, 16 cage B, 17 small ball bearing B, 18 flat raceway B, 19 key, 20 sealing ring B, 21 upper connecting block; 3a semicircular keyway; 3b groove; 3c stepped surface; 3d circular groove; 13a protrusion; 13b slideway. DETAILED DESCRIPTION

[0018] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and technical solutions.

[0019] Example 1

[0020] refer to Figures 1-4 , a mechanical low-frequency vibration generating device with adjustable amplitude, comprising:

[0021] like Figure 1 The figure shows a mechanical low-frequency vibration generating device with adjustable amplitude, which includes a bolt 1, a disc spring sheet 2, a lower connecting block 3, a sealing ring A4, a flat raceway A5, a small ball bearing A6, a retaining frame A7, a roller A8, an adjusting pin 9, an amplitude adjusting ring 10, a wave ring A11, a retaining frame linkage ring 12, a housing 13, a wave ring B14, a roller B15, a retaining frame B16, a small ball bearing B17, a flat raceway B18, a key 19, a sealing ring B20, and an upper connecting block 21.

[0022] In this embodiment, the bolt 1 passes through the disc spring sheet 2, the inner hole of the lower connecting block 3 and is connected to the internal thread of the upper connecting block 21; a semicircular keyway 3a is provided on the lower connecting block 3, and the cylindrical boss of the lower connecting block 3 passes through the plane raceway A5, the retainer A7, the wave ring A11, the retainer linkage ring 12, the wave ring B14, the retainer B16, and the plane raceway B18 in sequence and is connected to the upper connecting block 21 through the key 19, and a circular groove 3d is provided on the lower connecting block 3 for installing the sealing ring A4, and the outer surface of the cylindrical boss of the lower connecting block 3 is provided with two grooves 3b, which are respectively used to install the small ball A6 and the small ball B17; the plane raceway A5 and the upper connecting block are connected. The stepped surface 3c of the block 3 is in close contact; the small ball A6 and the small ball B17 are installed on the two grooves 3b of the lower connecting block 3, which are respectively used to connect the plane raceway A5 and the plane raceway B18 to ensure that the lower connecting block 3 rotates synchronously with the plane raceway A5 and the plane raceway B18; the roller A8 is fixed on the retainer A7 to form a thrust bearing, and the retainer A7 is provided with an arc groove for connecting the retainer linkage ring 12, and the roller A8 is in close contact with the plane raceway A5; the adjusting pin 9 is installed on the amplitude adjusting ring 10 and the wave ring A11, and has an interference fit with the amplitude adjusting ring 10 and the wave ring A11 to limit the relative rotation of the amplitude adjusting ring 10 and the wave ring A11; the wave ring A The left side of 11 is a sinusoidal wave surface, and the right side is a flat surface. The sinusoidal wave surface side of the wave ring A11 is in close contact with the roller A8, and the flat side of the wave ring A11 is in close contact with the flat side of the wave ring B14. A hole is provided on the outer circumference of the wave ring A11, which is interference fit with the adjusting pin 9; the two ends of the cage linkage ring 12 are respectively inserted into the arc grooves of the cage A7 and the cage B16 to ensure that the roller A8 and the roller B15 rotate synchronously; the housing 13 is in clearance fit with the amplitude adjustment ring 10, and the housing 13 is provided with a slideway 13b, which is in clearance fit with the adjusting pin 9. The adjusting pin 9 can slide on the slideway 13b, and the outer surface of the housing 13 is provided with a protrusion 13a for working time limit The outer shell 13 is restricted from rotating. The left side of the wave ring B14 is flat, and the right side is a sinusoidal wave surface. The flat side of the wave ring B14 is in close contact with the flat side of the wave ring A11, and the sinusoidal wave side of the wave ring B14 is in close contact with the roller B15. The roller B15 is fixed to the retainer B16 to form a thrust bearing. The roller B15 is in close contact with the wave ring B14 and the flat raceway B18. The retainer B16 has an arc groove for connecting to the retainer linkage ring 12. The key 19 is installed in the cylindrical keyway of the upper connecting block 21 to limit the relative rotation of the lower connecting block 3 and the upper connecting block 21. The sealing ring B20 is installed on the stepped surface at the left end of the upper connecting block 21 for sealing. When in use, the outer shell 13 is restricted from rotating, and the lower connecting block 3 and the upper connecting block 21 are connected to external equipment.When the adjustment pin 9 is controlled to cause the sinusoidal surfaces of the two wave rings to be in opposite phase, the amplitude of the axial low-frequency vibration is the sum of the amplitudes of the two wave rings' sinusoidal surfaces. When the adjustment pin 9 is controlled to cause the sinusoidal surfaces of the two wave rings to be in the same phase, there is no axial vibration, only axial feed motion of the tool. Furthermore, during low-frequency vibration, the frequency of the axial low-frequency vibration depends on the spindle speed and the number N / 2 of the annular sinusoidal curves on the wave rings (for every spindle rotation, there are N / 2 axial vibrations).

[0023] During operation, the housing 13 is restricted from rotating, and the lower connecting block 3 and the upper connecting block 21 are connected to external equipment. The specific working process is as follows: During rotation, the upper connecting block 21 drives the lower connecting block 4 to rotate synchronously, and rollers A8 and B15 roll on the sinusoidal wave surface of wave rings A11 and A14, respectively. Since the sinusoidal wave surface of wave rings A11 and A14 is a circular sine curve with N / 2 cycles, and during rotation, the disc spring 2 always applies an axial thrust to rollers A8 and B15 through the lower connecting block 3, thereby achieving an axial low-frequency vibration superimposed on the main shaft during rotation. The axial vibration of the vibrator is the superposition of two sinusoidal vibrations, and its equation is: When the adjustment pin 9 is controlled to cause the sinusoidal surfaces of the two wave rings to be in opposite phases, the amplitude of the axial low-frequency vibration is the sum of the amplitudes of the two wave rings' sinusoidal surfaces. When the adjustment pin 9 is controlled to cause the sinusoidal surfaces of the two wave rings to be in phase, there is no axial vibration, and only axial feed motion of the tool occurs. During low-frequency vibration, the frequency of the axial low-frequency vibration depends on the spindle speed and the number N / 2 of the annular sinusoidal curves on the wave rings (each spindle rotation produces N / 2 axial vibrations).

[0024] In this embodiment, the sinusoidal wave surfaces of both wave rings A11 and B14 are annular sinusoidal curves with five cycles. During low-frequency vibration, the main shaft vibrates 2.5 times in the axial direction for each rotation. The amplitude of the axial vibration can be varied by adjusting the phase difference between the sinusoidal surfaces of the two wave rings by controlling the sliding of the adjustment pin 9 within the slideway 13b of the housing 13. The frequency of the axial vibration can also be changed by replacing the wave rings.

Claims

1. A mechanical low-frequency vibration generating device with adjustable amplitude, characterized in that: The mechanical low-frequency vibration generating device with adjustable amplitude comprises a bolt (1), a disc spring sheet (2), a lower connecting block (3), a sealing ring A (4), a plane raceway A (5), a small ball bearing A (6), a retaining frame A (7), a roller A (8), an adjusting pin (9), an amplitude adjusting ring (10), a wave ring A (11), a retaining frame linkage ring (12), a housing (13), a wave ring B (14), a roller B (15), a retaining frame B (16), a small ball bearing B (17), a plane raceway B (18), a key (19), a sealing ring B (20) and an upper connecting block (21); The bolt (1) passes through the disc spring sheet (2), the lower connecting block (3) and the upper connecting block (21) in sequence; the cross section of the lower connecting block (3) is a T-shaped structure, and the lower connecting block (3) includes a base and a cylindrical boss; a semicircular keyway 3a is provided on the cylindrical boss of the lower connecting block (3), and the cylindrical boss of the lower connecting block (3) passes through the plane raceway A (5), the retainer A (7), the wave ring A (11), the retainer linkage ring (12), the wave ring B (14), the retainer B (16), and the plane raceway B (18) in sequence and is connected to the upper connecting block (21) through the key (19); a circular groove 3d is provided on the upper part of the lower connecting block (3) for installing the sealing ring A (4); two The groove 3b, the plane raceway A (5), and the plane raceway B (18) are respectively inserted into the two grooves 3b of the lower connecting block (3) through the small ball A (6) and the small ball B (17), and are further connected with the grooves on the plane raceway A (5) and the plane raceway B (18), so as to ensure that the lower connecting block (3) and the plane raceway A (5) and the plane raceway B (18) rotate synchronously; the surface where the base of the upper connecting block 3 and the cylindrical boss meet is a stepped surface 3c, and the plane raceway A (5) is in close contact with the stepped surface 3c of the upper connecting block 3; the roller A (8) is fixed on the retainer A (7) to form a thrust bearing, and the retainer A (7) is provided with an arc groove for connecting the retainer linkage ring (12), and the roller A (8) is in close contact with the plane raceway A (5); the adjusting pin (9) is installed on the amplitude adjusting ring (10) and the wave ring A (11), and is interference fit with the amplitude adjusting ring (10) and the wave ring A (11), limiting the relative rotation of the amplitude adjusting ring (10) and the wave ring A (11); a hole is opened on the amplitude adjusting ring (10) for installing the adjusting pin (9); the left side of the wave ring A (11) is a sine wave surface, and the right side is a plane. The sine wave surface side of the wave ring A (11) is in close contact with the roller A (8), and the plane side of the wave ring A (11) is in close contact with the plane side of the wave ring B (14). A hole is opened on the outer circumference of the wave ring A (11), which is interference fit with the adjusting pin (9); the two ends of the cage linkage ring (12) are respectively inserted into the cage A (7 ) and the arc groove of the retainer B (16), ensuring that roller A (8) and roller B (15) rotate synchronously, thereby ensuring that roller A (8) and roller B (15) are in the same phase; the housing (13) is clearance-matched with the amplitude adjustment ring (10), and the housing (13) is provided with a slideway 13b, which is clearance-matched with the adjustment pin (9), and the adjustment pin (9) can slide on the slideway 13b. The outer surface of the housing (13) is provided with a protrusion 13a, which is used to limit the rotation of the housing (13) during operation; the left side of the wave ring B (14) is a plane, and the right side is a sine wave surface. The plane side of the wave ring B (14) is in close contact with the plane side of the wave ring A (11), and the sine wave surface side of the wave ring B (14) is in close contact with the roller B (15);Roller B (15) is fixed on cage B (16) to form a thrust bearing. Roller B (15) is in close contact with wave ring B (14) and plane raceway B (18). Cage B (16) is provided with an arc groove for connecting cage linkage ring (12). The cross section of the upper connecting block (21) is stepped. The end face of one end thereof is provided with a sealing ring B (20) for sealing. The key (19) is installed in the cylindrical keyway of the upper connecting block (21) to limit the relative rotation of the lower connecting block (3) and the upper connecting block (21).

2. The mechanical low-frequency vibration generating device with adjustable amplitude according to claim 1, characterized in that: An axial low-frequency vibration is achieved by superposition of the axial vibrations generated by the rolling of the rollers A (8) and B (15) on the wave rings A (11) and B (14), respectively. The wave rings A (11) and B (14) contain the same number of sinusoidal curve periods and the same amplitude.

3. The mechanical low-frequency vibration generating device with adjustable amplitude according to claim 1, characterized in that: The retainer A (7) and the retainer B (16) are provided with a plurality of arc grooves for connecting the retainer linkage ring (12) to ensure synchronous rotation of the roller A (8) and the roller B (15), and to ensure that the roller A (8) and the roller B (15) are in the same phase.

4. The mechanical low-frequency vibration generating device with adjustable amplitude according to claim 1, characterized in that: By controlling the sliding of the adjusting pin (9) in the slideway 13b of the housing (13), the phase difference between the sinusoidal surfaces of the wave ring A (11) and the wave ring B (14) can be adjusted to change the amplitude of the axial vibration.

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