A reinforcement device, structure, lathe apparatus and reinforcement method

Abstract

A reinforcing device, structure, lathe apparatus and reinforcing method, wherein the reinforcing device comprises: an ultrasonic main body; a variable amplitude rod arranged on the ultrasonic main body and configured to control the amplitude of ultrasonic waves; and a reinforcing head arranged on the variable amplitude rod and having a reinforcing part opposite to a rotary chamfered surface; the ultrasonic main body is configured to drive the reinforcing part to perform ultrasonic vibration directed to the rotary chamfered surface to perform reinforcing treatment on the rotary chamfered surface.

Description

TECHNICAL FIELD

[0001] The present application relates to a rotary chamfering strengthening technology, in particular to a strengthening device, a structure, a lathe equipment and a strengthening method. BACKGROUND

[0002] In the aircraft structure, the load-bearing hole is one of the structures that are prone to fatigue fracture problems. Because of its discontinuity, the defects generated at this point are easily amplified due to stress concentration under alternating loads, thereby causing fatigue fracture. Statistics show that 50%-90% of aircraft failures are caused by fatigue failure of the hole structure, and since fatigue fracture is not easy to detect before it occurs, it is difficult to detect, and therefore it is often easy to cause catastrophic accidents. To solve this problem, the fatigue performance of the load-bearing hole needs to be improved, and the most common one is the surface strengthening technology which can effectively improve the fatigue life of the load-bearing hole wall.

[0003] At present, the hole wall strengthening technology mainly includes extrusion, rolling, shot peening strengthening, etc. However, in the process of hole surface strengthening, the current research often only strengthens the inner wall of the hole, and ignores the chamfer part of the hole edge. Existing research shows that the load-bearing hole structure after hole wall strengthening.

[0004] Because the chamfer part is not strengthened, the surface integrity is poor, and there is stress concentration at the transition position of the chamfer and the hole wall due to material flow, so the fatigue crack source of the load-bearing hole after the inner wall strengthening is often the chamfer position at the entrance of the hole. Because the chamfer of the hole edge is too small in size and has an inclination problem, it cannot be strengthened by traditional surface strengthening methods, which seriously affects the service life of the load-bearing hole. SUMMARY

[0005] The present application provides a strengthening device, a structure, a lathe equipment and a strengthening method, which can realize the surface strengthening treatment of the rotary chamfer.

[0006] The present application provides a strengthening device, which comprises:

[0007] An ultrasonic main body;

[0008] An amplitude transformer arranged in the ultrasonic main body and configured to control the amplitude of the ultrasonic waves output by the ultrasonic main body;

[0009] A strengthening head arranged in the amplitude transformer and having a strengthening part, the strengthening part being arranged to be opposite to the surface of the rotary chamfer;

[0010] The ultrasonic main body is configured to drive the strengthening part to perform ultrasonic vibration towards the surface of the rotary chamfer to strengthen the rotary chamfer.

[0011] In an exemplary embodiment, the ultrasonic body is configured to drive the strengthening part to longitudinally vibrate relative to the rotary chamfer, wherein the longitudinal vibration refers to ultrasonic vibration of the strengthening part perpendicular to the surface of the rotary chamfer.

[0012] In an exemplary embodiment, the strengthening head is in the shape of a tapered elongated body, the strengthening part is arranged on the conical surface of the strengthening head, and the direction of the longitudinal vibration coincides with the axis of the strengthening head.

[0013] In an exemplary embodiment, the ultrasonic body is configured to drive the strengthening part to ultrasonically vibrate along a sinusoidal curve trajectory relative to the rotary chamfer surface.

[0014] In an exemplary embodiment, the relationship between the pre-pressing depth of the strengthening part and the amplitude of the ultrasonic body satisfies one of the following:

[0015] The first relationship: when the hardness of the rotary chamfer is in the range of 50-70HRC, the pre-pressing depth is in the range of -A < h < 0;

[0016] The second relationship: when the hardness of the rotary chamfer is in the range of 30-60HRC, the pre-pressing depth is in the range of 0 < h < A;

[0017] The third relationship: when the hardness of the rotary chamfer is in the range of 20-40HRC, the pre-pressing depth is h > A;

[0018] Wherein, h represents the pre-pressing depth, and A represents the amplitude; the pre-pressing depth is the distance between the strengthening part and the surface of the rotary chamfer.

[0019] In an exemplary embodiment, the elongated direction of the strengthening head is configured to form an acute angle with the feeding direction of the lathe tool holder, and the angle of the acute angle is the same as the angle of the rotary chamfer;

[0020] The strengthening device further comprises a mounting portion arranged on the ultrasonic body and capable of being connected to the lathe tool holder, and the elongated direction of the mounting portion forms an obtuse angle with the elongated direction of the strengthening head so that the elongated direction of the strengthening head can form the acute angle with the feeding direction of the lathe tool holder.

[0021] In an exemplary embodiment, the strengthening device further comprises a clamp capable of being connected to the lathe tool holder and the mounting portion, the clamp comprises a clamping portion matched with the mounting portion for clamping, and the mounting portion can be adjusted in position in the clamping portion so that the strengthening head can strengthen rotary chamfers of different angles.

[0022] This application provides a reinforcement structure, including the reinforcement device described in any of the above embodiments and a rotary chamfer; the reinforcement portion of the reinforcement device is opposite to the surface of the rotary chamfer, the rotary chamfer is configured to be rotatable, and the reinforcement device is configured such that ultrasonic vibrations output from its reinforcement portion can be directed to impact the surface of the rotary chamfer to strengthen the rotary chamfer.

[0023] This application provides a lathe device, including a lathe body with a tool post, a strengthening device as described in any of the above embodiments disposed on the tool post, and a driving device. The driving device is configured to clamp a workpiece with a chamfer and drive the workpiece to rotate. The strengthening device is configured to strengthen the surface of the chamfer during the rotation of the workpiece.

[0024] This application provides a strengthening method for the strengthening device as described in any of the above embodiments, including:

[0025] When the chamfer angle between the strengthening device and the workpiece meets the predetermined requirements, the workpiece is driven to rotate.

[0026] The strengthening device is activated to provide ultrasonic vibrations directed at the chamfered surface to strengthen the chamfered surface.

[0027] In one exemplary embodiment, the predetermined requirement includes: the pre-compression depth of the reinforcing device and the ultrasonic impact amplitude satisfy one of the following relationships:

[0028] First relationship: When the hardness of the chamfer is in the range of 50-70 HRC, the pre-compression depth range is: -A <h≤0;

[0029] The second relationship: When the hardness of the chamfer is in the range of 30-60 HRC, the pre-compression depth range is: 0. <h≤A;

[0030] The third relationship: When the hardness of the chamfer is in the range of 20-40 HRC, the pre-compression depth is h>A.

[0031] In an exemplary embodiment, the predetermined requirement includes: when the first relationship or the second relationship is satisfied, the motion trajectory of the reinforcing device relative to the surface of the chamfer is a sine curve, and its motion trajectory satisfies the following formula:

[0032]

[0033] Where n represents the workpiece rotation speed, R0 represents the workpiece inner hole radius, A represents the ultrasonic impact amplitude, f represents the ultrasonic impact vibration frequency; θ represents the rotation angle of the chamfer; r represents the radial displacement of the reinforced part; and z represents the axial displacement of the reinforced part.

[0034] In one exemplary embodiment, the predetermined requirement includes:

[0035] The duty cycle D of the strengthening device per cycle c Satisfying the formula:

[0036] The distance δ between the two impacts of the strengthening device satisfies the formula:

[0037] In one exemplary embodiment, the predetermined requirement includes: the rotational speed range of the workpiece is greater than 100 rpm.

[0038] Compared with related technologies, the strengthening device of this application embodiment can perform ultrasonic impact strengthening on the rotary chamfer, effectively improving the surface integrity of the rotary chamfer, thereby further improving the fatigue life of the hole structure.

[0039] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the application. Other advantages of this application can be realized and obtained by means of the solutions described in the description and the accompanying drawings. Attached Figure Description

[0040] The accompanying drawings are used to provide an understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0041] Figure 1 This is a schematic diagram of the strengthening device according to an embodiment of this application;

[0042] Figure 1 a for Figure 1 A magnified view of a reinforced area;

[0043] Figure 2 This is a perspective view of a workpiece with a chamfered corner according to an embodiment of this application;

[0044] Figure 3 This is a side sectional view of a workpiece with a chamfered corner according to an embodiment of this application;

[0045] Figure 4 This is a motion coordinate diagram of the reinforcing part of the reinforcing device in this application embodiment relative to a point on the chamfered surface;

[0046] Figure 5 for Figure 4 Three-dimensional trajectory coordinate diagram of vibration at point B;

[0047] Figure 6aThis is a schematic diagram of the contact-separation motion trajectory relative to the workpiece when the pre-compression depth of the strengthening part of the strengthening device in this application and the amplitude of the ultrasonic body satisfy the first relationship;

[0048] Figure 6b This is a schematic diagram of the contact-separation motion trajectory relative to the workpiece when the pre-compression depth of the strengthening part of the strengthening device in this application and the amplitude of the ultrasonic body satisfy the second relationship;

[0049] Figure 6c This is a schematic diagram of the contact-separation motion trajectory relative to the workpiece when the pre-compression depth of the strengthening part of the strengthening device in this application and the amplitude of the ultrasonic body satisfy the second relationship;

[0050] Figure 7 This is a schematic diagram of workpiece deformation caused by the movement of the reinforcing head on the chamfered surface according to an embodiment of this application;

[0051] Figure 8 This is a simplified model of the ultrasonic impact process in the embodiments of this application;

[0052] Figure 9 This is a schematic diagram showing the distance between two impacts on the surface of the rotating chamfered corner of the reinforcing device according to an embodiment of this application.

[0053] Figure 10 The surface roughness of the rotary chamfer under different process parameters in the embodiments of this application;

[0054] Figure 11 This is a microstructure diagram of the chamfer after ultrasonic shock strengthening according to an embodiment of this application;

[0055] Figure 12 The thickness of the hardened layer on the workpiece under different process parameters in the embodiments of this application;

[0056] Figure 13 The residual stress on the workpiece surface under different process parameters in the embodiments of this application.

[0057] Figure 14 This is a flowchart of the enhanced method according to an embodiment of this application. Detailed Implementation

[0058] This application describes several embodiments, but these descriptions are exemplary and not restrictive, and it will be apparent to those skilled in the art that many more embodiments and implementations are possible within the scope of the embodiments described herein. Although many possible combinations of features are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with, or may replace, any feature or element of any other embodiment.

[0059] This application includes and contemplates combinations of features and elements known to those skilled in the art. The embodiments, features, and elements disclosed in this application may also be combined with any conventional features or elements to form a unique inventive scheme as defined by the claims. Any feature or element of any embodiment may also be combined with features or elements from other inventive schemes to form another unique inventive scheme as defined by the claims. Therefore, it should be understood that any feature shown and / or discussed in this application may be implemented individually or in any suitable combination. Therefore, the embodiments are not limited except by the limitations imposed by the appended claims and their equivalents. Furthermore, various modifications and changes may be made within the scope of the appended claims.

[0060] Furthermore, in describing representative embodiments, the specification may have presented methods and / or processes as a specific sequence of steps. However, the method or process should not be limited to the specific order of steps described herein, to the extent that it does not depend on such a specific order. As will be understood by those skilled in the art, other sequences of steps are also possible. Therefore, the specific order of steps set forth in the specification should not be construed as a limitation of the claims. Moreover, the claims concerning the method and / or process should not be limited to the steps performed in the written order, and those skilled in the art will readily understand that these orders can be varied and still remain within the spirit and scope of the embodiments of this application.

[0061] like Figure 1 , Figure 1 a As shown, this application provides a strengthening device 1, including: an ultrasonic body 10; an amplitude transformer 11 disposed on the ultrasonic body 10 and configured to control the amplitude of the ultrasonic waves output by the ultrasonic body 10; and a strengthening head 12 disposed on the amplitude transformer 11 and having a strengthening portion 120 opposite to the surface of the chamfer 20. The ultrasonic body 10 is configured to drive the strengthening portion 120 to perform ultrasonic vibration directed towards the surface of the chamfer 20 to strengthen the chamfer 20.

[0062] Among them, the rotary chamfer is the chamfering of the hole edge or shaft end of a rotatable product, which is generally a workpiece. The ultrasonic body 10 can generate ultrasonic waves, for example, the user converts the input electrical signal into an ultrasonic vibration signal through piezoelectric ceramics using an ultrasonic transducer.

[0063] The strengthening device 1 of this application embodiment can perform ultrasonic impact strengthening on the chamfer 20, effectively improving the surface quality of the chamfer 20, thereby further improving the fatigue life of the hole structure. The surface quality includes surface roughness, surface residual stress, subsurface microstructure, and other qualities.

[0064] In addition, the strengthening device 1 of this application embodiment can strengthen the slewing chamfer 20 with characteristics such as excessively small chamfer size and tilt angle, thus solving the problem of slewing chamfers that cannot be strengthened using traditional strengthening methods.

[0065] In this embodiment, the ultrasonic body 10 is cylindrical. A portion of the amplitude transformer 11 is installed within the ultrasonic body 10, while another portion extends beyond the exterior of the ultrasonic body 10. The reinforcing head 12 is fixedly connected to the end of the portion extending from the ultrasonic body 10. The ultrasonic body 10 also has a power interface 102 that can be connected to an ultrasonic power supply. The reinforcing device 1 drives the transducer to vibrate by connecting to the ultrasonic body 10. The transducer amplitude is amplified by the amplitude transformer 11, ultimately driving the reinforcing head 12 to achieve longitudinally stable ultrasonic frequency vibration.

[0066] The strengthening device 1 in this embodiment can be connected to the ultrasonic control system, enabling controllable adjustment of the ultrasonic vibration of the strengthening device 1 and the strengthening and vibration parameters. This allows for high-precision strengthening of the rotary chamfer 20 by ultrasonic impact, resulting in a highly regular and smooth chamfer surface profile. The strengthening parameters include the pre-compression depth of the strengthening portion 120, the rotational speed of the workpiece 2 with the rotary chamfer 20, and the strengthening time. The vibration parameters include the amplitude and frequency of the strengthening portion 120 of the strengthening device 1. The pre-compression depth can be adjusted manually or automatically by the machine tool 100. First, it is confirmed that the strengthening head 12 is in contact with the surface of the rotary chamfer 20, and then the feed rate of the lathe is adjusted.

[0067] like Figure 1 As shown, in order to ensure that the strengthening head 12 can process the chamfer 20 of the workpiece 2, in this embodiment of the application, the extension direction H of the strengthening head 12 is set to form an acute angle α with the feed direction G of the tool post 101 of the lathe 100, and the angle of the acute angle α is set to be the same as the angle of the chamfer 20, so that the strengthening part 120 faces the surface of the chamfer 20.

[0068] The strengthening device 1 in this embodiment also includes a mounting portion 13 disposed on the ultrasonic body 10 and capable of connecting to the tool holder 101 of the lathe 100. The extension direction of the mounting portion 13 forms an obtuse angle with the extension direction I of the strengthening head 12 so that the extension direction H of the strengthening head 12 is set to form an acute angle α with the feed direction G of the tool holder 101 of the lathe 100.

[0069] like Figure 1 As shown, the strengthening device 1 in this embodiment also includes a clamp 14 that connects the tool holder 101 of the lathe 200 and the mounting part 13. The tool holder 101 has a tool head 103, and the clamp 14 is mounted on the tool head 103. The clamp 14 includes a clamping part 140 that cooperates with the mounting part 13 to clamp. The mounting part 13 can be adjusted in position in the clamping part 140 so that the strengthening head 12 can strengthen the chamfer 20 of different angles. This adjustment can be done manually or automatically by the machine tool 100. In this embodiment, the mounting part 13 is plate-shaped, and the clamping part 140 is a clamping jaw. The plate-shaped mounting part 13 is inserted into the clamping jaw and can be adjusted in position within the clamping jaw. After adjustment, it is locked with bolts.

[0070] like Figure 2 , Figure 3 As shown, in this embodiment of the application, the ultrasonic body 1 is configured to drive the reinforced part 120 to vibrate longitudinally relative to the chamfer 20. The longitudinal vibration refers to the ultrasonic vibration of the reinforced part 120 perpendicular to the surface of the chamfer 20, so that the impact force can be applied to the surface of the chamfer 20 to the maximum extent, thereby achieving a significant reinforcement effect.

[0071] For example, such as Figure 1 As shown, in this embodiment, the reinforcing head 12 is elongated in a reduced diameter shape, and the reinforcing part 120 is provided on the conical surface of the reinforcing head 12. The longitudinal vibration direction F coincides with the axis of the reinforcing head 12 so that the ultrasonic body 1 can be vertically impacted along the surface of the chamfer 20.

[0072] like Figure 2 , Figure 3 As shown, the ultrasonic body 1 is configured to drive the reinforced part 120 to perform ultrasonic vibration relative to the rotating chamfer 20 surface in accordance with a sinusoidal motion trajectory, thereby improving the reinforcement uniformity and high coverage of the reinforced surface.

[0073] During the ultrasonic impact strengthening process of the ultrasonic body 1 (i.e., the ultrasonic body 1 undergoes high-frequency ultrasonic impact), the strengthening head 12 generates longitudinal vibration while the workpiece 2 with the chamfer 20 rotates at high speed. Therefore, the motion trajectory of the strengthening part 120 of the strengthening head 12 on the surface of the chamfer 20 is a sine curve (see...). Figure 3 (Simulated sine curve with a mid-amplitude range of 2A).

[0074] To achieve enhanced uniformity and high coverage of the rotary chamfer 20, the movement trajectory of the strengthening part 120 of the strengthening head 12 on the surface of the rotary chamfer 20 satisfies the following formula:

[0075]

[0076] In the above formula, n represents the rotational speed of the workpiece, R0 represents the inner hole radius of the workpiece, A represents the ultrasonic impact amplitude, f represents the ultrasonic impact vibration frequency, θ represents the rotational angle of the workpiece, r represents the radial displacement of the strengthening part, and z represents the axial displacement of the strengthening part.

[0077] As Figure 4 、 Figure 5 shown, it presents the movement trajectory curve of the strengthening part 120 on the surface of the rotary chamfer 20. Among them Figure 4 shows the two-dimensional coordinate trajectory of the movement of the strengthening part 120 relative to a point on the surface of the rotary chamfer 20, and the movement mode of the workpiece 2 refers to Figure 2 shown; Figure 5 shows Figure 4 the three-dimensional trajectory coordinate diagram of the movement of part B in: In this figure, the rotary chamfer 20 is 45 degrees. When the workpiece 2 rotates one week and there is no ultrasonic vibration, the vibration curve is a straight line (as shown by the dotted line in the figure); when the workpiece 2 rotates one week and there is ultrasonic vibration, the vibration curve is a sine curve (as shown by the toothed line in the figure). It can be concluded from the figure that the strengthening device 1 of the embodiment of the present application has high strengthening uniformity and high coverage for the rotary chamfer 20.

[0078] As Figures 6a-6c shown, in this embodiment, the relationship between the preloading depth of the strengthening part 120 and the amplitude of the ultrasonic main body 1 satisfies the following relationship:

[0079] As Figure 6a shown, the first relationship: When the hardness of the rotary chamfer 20 is in the range of 50 - 70 HRC, the preloading depth range is: -A < h ≤ 0. In this range, there is a contact-separation cycle between the strengthening head 12 and the rotary chamfer 20, and its strengthening time is shorter than the separation time (as Figure 6a shown). The closer h is to -A, the shorter the strengthening time and the longer the separation time. This preloading depth range is suitable for materials with higher hardness and can prevent the strengthening head 12 from being damaged. As Figure 6a shown, there is a gap between the strengthening part 120 and the surface of the rotary chamfer 20, and the gap distance is h. Among them, h represents the preloading depth, A represents the amplitude, and Vc in the figure represents the velocity direction of the strengthening head.

[0080] As Figure 6bAs shown, the second relationship: when the hardness of the rotary chamfer 20 is within the range of 30 - 60 HRC, the preloading depth range is: 0 < h ≤ A. (2) When 0 < h ≤ A. In this range, there is also a contact - separation cycle between the strengthening head 12 and the workpiece 2, and the strengthening time is longer than the separation time (as Figure 6b shown). The closer h is to 0, the closer its strengthening time is to the separation time. This preloading depth range is suitable for materials with moderate hardness to ensure the strengthening treatment effect. As Figure 6b shown, there is no gap between the strengthening part 120 and the surface of the rotary chamfer 20 and it is pressed into the workpiece 2 by a distance of h.

[0081] As Figure 6c shown, the third relationship: when the hardness of the said rotary chamfer is within the range of 20 - 40 HRC, the preloading depth is h > A. When h > A. In this range, there is no separation between the strengthening head 12 and the workpiece 2, that is, the strengthening head 12 and the workpiece 2 are in continuous contact, as Figure 6c shown. This preloading depth range is suitable for materials with relatively soft hardness to enhance the strengthening treatment effect. As Figure 6c shown, there is no gap between the strengthening part 120 and the surface of the rotary chamfer 20 and it is pressed into the workpiece 2 by a distance of h.

[0082] The preloading depth is the distance between the strengthening part 120 and the surface of the rotary chamfer 20. When the strengthening part 120 of the strengthening device 1 just contacts the rotary chamfer 20 surface of the workpiece 2, the cylindrical surface (strengthening part 120) at the tip of the strengthening head 12 is tangent to the surface of the rotary chamfer 20 of the workpiece 2, and at this time the preloading depth is 0.

[0083] The strengthening device 1 of the embodiment of the present application can ensure a high strengthening coverage rate by setting the relationship between the preloading depth and the ultrasonic amplitude. And the strengthening device 1 of the embodiment of the present application can achieve a high strengthening treatment effect for the rotary chamfers 20 of different materials by setting the relationship between the preloading depth and the ultrasonic amplitude.

[0084] For the cases of the first relationship and the second relationship, there is a contact - separation cycle between the strengthening head 12 and the surface of the rotary chamfer 20, and the duty cycle D of each cycle can be obtained c satisfies the following formula:

[0085]

[0086] The strengthening device 1 of the embodiment of the present application can obtain a regular chamfer surface profile. The regular chamfer surface profile means that after the surface of the rotary chamfer 20 of the workpiece 2 is subjected to the high - frequency impact of the strengthening device 1, the surface is deformed, and the deformed part is the envelope line generated by the strengthening head moving along a sine curve (as Figure 7 shown). As Figure 8 shown, when the impact pressure F, the radius of the strengthening head Rc, the maximum preloading depth hmax At that time, the elastically deformed part rebounds after unloading (e.g. Figure 8 (As shown in the cross-section), the width of plastic deformation d p .like Figure 9 As shown, the plastically deformed portion forms a regular surface profile after unloading. The spacing δ of the marks left between the two impacts satisfies the following formula:

[0087]

[0088] The strengthening device 1 of this application embodiment can efficiently strengthen the chamfer 20, significantly improving its surface integrity indicators such as surface roughness, residual stress, and subsurface microstructure, thereby improving the fatigue life of the hole structure.

[0089] In summary, the strengthening device 1 of this application embodiment has the ability to perform efficient surface treatment with high coverage and high controllability.

[0090] In an exemplary embodiment, during the strengthening process, the workpiece 2 is made of 45 steel, its inner diameter is 20mm, the chamfer 20 has a size of 1mm, and the angle of the chamfer 20 is 45°. Correspondingly, the acute angle α is also 45°, thereby achieving... Figure 1 The strengthening head 12 is positioned opposite the rotary chamfer 20. During the strengthening process, the workpiece 2 is clamped in the lathe 100, and the strengthening device 1 is mounted on the tool head 103 of the lathe 100 via a fixture 13. During strengthening, firstly, the spindle speed, vibration frequency, vibration amplitude, and other vibration parameters of the lathe 100's drive device are set; then, the position of the ultrasonic body 1 is adjusted so that the strengthening head 12 is opposite the surface of the rotary chamfer 20, and a corresponding pre-compression depth is set. Finally, under normal temperature coolant conditions, the strengthening device 1 and the lathe 100 are turned on, the workpiece 2 rotates, and after the preset strengthening time is reached, the lathe 100 and the strengthening device 1 are turned off, thus completing the high-speed ultrasonic impact strengthening of the rotary chamfer 20 surface.

[0091] Research has shown that when the strengthening time is 30s, the rotation speed of workpiece 2 is 500rpm, and the pre-compression depth is 0, the surface roughness is reduced by about 91.2% compared to the original surface, the tool marks on the original surface disappear, a clear hardened layer appears in the microstructure, and residual compressive stress is introduced at the edge of the hole, which greatly improves the surface quality of the chamfer.

[0092] The strengthening device, structure, lathe equipment, and strengthening method of this application overcome the problem that the chamfer 20 cannot be strengthened by traditional surface strengthening methods due to its small size and tilt angle. Furthermore, the high-precision and highly controllable strengthening of the chamfer is achieved through ultrasonic system control.

[0093] The strengthening device, structure, lathe equipment, and strengthening method of this application can effectively reduce the surface roughness of the chamfer. See also Figure 10 When compared under different strengthening parameters (spindle speed, strengthening time, preload depth), its roughness can be reduced by up to about 91.2%.

[0094] The strengthening device, structure, lathe equipment, and strengthening method of this application embodiment can form a strengthening structure on the surface of the chamfer 20, thereby improving surface integrity, such as... Figure 11 As shown, the microstructure of the 20° chamfered corner exhibits grain refinement, and the grains are elongated along the chamfer direction, resulting in a distinct deformation layer with a thickness of 52.15 μm.

[0095] The strengthening device, structure, lathe equipment, and strengthening method of this application embodiment can cause significant tangential flow of the surface material at the chamfer, while the subsurface grains are elongated, and a strengthening layer of a certain thickness is formed on the chamfer surface. See [link to relevant documentation]. Figure 11 Its hardened layer thickness can reach up to 52.63 μm, refer to Figure 12 (As shown).

[0096] The strengthening device, structure, lathe equipment, and strengthening method of this application embodiment are compared under different strengthening parameters (spindle speed, strengthening time, preload depth). They can introduce residual compressive stress of over 200 MPa into the original 156 MPa residual tensile stress on the chamfered 20 surface. See [link to relevant documentation]. Figure 13 .

[0097] This application provides a strengthening structure, including a strengthening device 1 as described in any of the above embodiments, and a chamfer 2. The strengthening portion 120 of the strengthening device 1 is opposite to the surface of the chamfer 20. The chamfer 20 is configured to be rotatable. The strengthening device 1 is configured such that ultrasonic vibrations output from its strengthening portion 120 can be directed to impact the surface of the chamfer 20 to strengthen it.

[0098] This application provides a lathe device, including a lathe body with a tool post, a strengthening device 1 as described in any of the above embodiments, and a driving device (not shown) disposed on the tool post. The driving device is configured to clamp a workpiece with a chamfer 20 and drive the workpiece 2 to rotate. The strengthening device 1 is configured to strengthen the chamfer surface r during the rotation of the workpiece 2.

[0099] like Figure 14 As shown, this application embodiment provides a method for strengthening the chamfer 20 of the strengthening device 1 as described in any of the above embodiments, including the following operations:

[0100] S1. When the chamfer 20 between the strengthening device 1 and the workpiece 2 meets the predetermined requirements, drive the chamfer 20 to rotate.

[0101] S2. Start the strengthening device 1 and provide ultrasonic vibration directed at the surface of the chamfer 20 to strengthen the surface of the chamfer 20.

[0102] The predetermined requirements described in operation S1 include one of the following relationships between the pre-compression depth of the reinforcing device 1 and the ultrasonic impact amplitude:

[0103] First relationship: When the hardness of the chamfer is in the range of 50-70 HRC, the pre-compression depth range is: -A <h≤0;

[0104] The second relationship: When the hardness of the chamfer is in the range of 30-60 HRC, the pre-compression depth range is: 0. <h≤A;

[0105] The third relationship: When the hardness of the chamfer is in the range of 20-40 HRC, the pre-compression depth is h>A;

[0106] Where h represents the pre-compression depth and A represents the ultrasonic impact amplitude; the pre-compression depth is the distance between the reinforced part of the reinforcing device and the chamfered surface.

[0107] The predetermined requirements of operation S1 include: when the first relationship or the second relationship is satisfied, the motion trajectory of the strengthening device 1 relative to the surface of the chamfer 20 is a sine curve, and its motion trajectory satisfies the following formula:

[0108]

[0109] Where n represents the workpiece rotation speed, R0 represents the workpiece inner hole radius, A represents the ultrasonic impact amplitude, and f represents the ultrasonic impact vibration frequency.

[0110] The predetermined requirements for operation S1 include: the duty cycle D of the strengthening device 1 per cycle. c The formula is:

[0111]

[0112] The predetermined requirements of operation S1 include: the distance δ of the mark left between two impacts of the strengthening device 1 satisfies the formula:

[0113]

[0114] The predetermined requirements for operation S1 include: the rotational speed range of the workpiece 2 is greater than 100 rpm. While the strengthening device 1 generates longitudinal vibration, the workpiece 2 rotates at high speed relative to the strengthening head 12, thereby enabling the strengthening device 1 to perform high-coverage controllable ultrasonic impact on the chamfer 2, significantly improving the surface integrity of the chamfer 2, such as surface roughness, surface residual stress, and subsurface microstructure, thereby further improving the fatigue life of the hole structure.

[0115] For example, this application provides a high-speed ultrasonic shock strengthening method for rotary chamfering, the implementation steps of which are as follows:

[0116] Step 1: Install the strengthening device 1 on the corresponding machine tool 100 and fixture 13 so that the tool head 12 can generate longitudinal vibration;

[0117] Step 2: Install workpiece 2 on machine tool 100, and move strengthening device 1 so that the strengthening part 120 of the strengthening head is opposite to the chamfer 20 of workpiece 2.

[0118] Step 3: Set the strengthening parameters and vibration parameters so that the surface can be subjected to high-frequency impact, thereby forming a regular surface profile on the surface of the rotary chamfer 20 and achieving efficient strengthening of the rotary chamfer 20.

[0119] Step 4: Turn on the strengthening device 1 and machine tool 100 to complete the strengthening process of rotary chamfering.

[0120] In the description of this application, it should be noted that the terms "upper", "lower", "one side", "the other side", "one end", "the other end", "side", "opposite", "four corners", "periphery", "square structure", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the structure referred to has a specific orientation, or is constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0121] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the terms "connection," "direct connection," "indirect connection," "fixed connection," "installation," and "assembly" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. The terms "installation," "connection," and "fixed connection" can refer to a direct connection or an indirect connection through an intermediate medium, or they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0122] Although the embodiments disclosed in this application are as described above, the content described is merely for the purpose of understanding this application and is not intended to limit this application. Any person skilled in the art to which this application pertains may make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in this application, but the scope of patent protection of this application shall still be defined by the appended claims.

Claims

1. A strengthening device, characterized in that, include: Ultrasound body; An amplitude transformer is provided on the ultrasonic body and is configured to control the amplitude of the ultrasonic waves output by the ultrasonic body; A reinforcing head is provided on the amplitude rod and has a reinforcing part, the reinforcing part being fitted to face the surface of the slewing chamfer; The ultrasonic body is configured to drive the reinforced part to perform ultrasonic vibration directed towards the surface of the rotary chamfer to reinforce the rotary chamfer. The pre-compression depth of the reinforced portion and the amplitude of the ultrasonic body are related by one of the following: The first relationship: When the hardness of the chamfer is in the range of 50-70 HRC, the pre-compression depth range is: ; The second relationship: When the hardness of the chamfer is in the range of 30-60 HRC, the pre-compression depth range is: ; The third relationship: When the hardness of the chamfer is in the range of 20-40 HRC, the pre-compression depth is... ; in, Indicates the preload depth. The amplitude of the ultrasonic impact is indicated; the pre-compression depth is the distance between the reinforced portion and the chamfered surface. When either the first or second relationship is satisfied, the motion trajectory of the strengthening device relative to the surface of the chamfer is a sine curve, and its motion trajectory satisfies the following formula: in, Indicates the rotational speed of the workpiece. Indicates the inner diameter of the workpiece. Indicates the amplitude of ultrasonic impact. Indicates the frequency of ultrasonic impact vibration; Indicates the rotation angle of the chamfer; Indicates the radial displacement of the reinforced area; t represents the axial displacement of the reinforced part, and t represents the time it takes for the workpiece to rotate.

2. The strengthening device according to claim 1, characterized in that, The ultrasonic body is configured to drive the reinforced part to vibrate longitudinally relative to the chamfer, wherein the longitudinal vibration refers to the ultrasonic vibration of the reinforced part perpendicular to the surface of the chamfer.

3. The strengthening device according to claim 2, characterized in that, The reinforcing head is elongated in a tapered shape, the reinforcing portion is located on the conical surface of the reinforcing head, and the longitudinal vibration direction coincides with the axis of the reinforcing head.

4. The strengthening device according to claim 2, characterized in that, The ultrasonic body is configured to drive the reinforced part to perform ultrasonic vibration relative to the rotating chamfered surface in accordance with a sinusoidal motion trajectory.

5. The strengthening device according to any one of claims 1-4, characterized in that, The extension direction of the reinforcing head is fitted to form an acute angle with the feed direction of the lathe tool post, and the angle of the acute angle is the same as the angle of the chamfer. The strengthening device further includes a mounting part disposed on the ultrasonic body and capable of connecting to the lathe tool post. The extension direction of the mounting part forms an obtuse angle with the extension direction of the strengthening head so that the extension direction of the strengthening head can form an acute angle with the feed direction of the lathe tool post.

6. The strengthening device according to claim 5, characterized in that, It also includes a fixture capable of connecting the lathe tool post and the mounting part, the fixture including a clamping part that cooperates with the mounting part to clamp, the mounting part being adjustable in position to enable the strengthening head to strengthen the chamfer at different angles.

7. A reinforcing structure, characterized in that, Includes a strengthening device as described in any one of claims 1-6, and a rotary chamfer; the strengthening portion of the strengthening device is opposite to the surface of the rotary chamfer, the rotary chamfer is configured to be rotatable, and the strengthening device is configured such that ultrasonic vibrations output from its strengthening portion can be directed to impact the surface of the rotary chamfer to strengthen the rotary chamfer.

8. A lathe device, characterized in that, The lathe body includes a tool post, a strengthening device as described in any one of claims 1-6 disposed on the tool post, and a driving device, the driving device being configured to clamp a workpiece having a chamfer and drive the workpiece to rotate, and the strengthening device being configured to strengthen the surface of the chamfer during the rotation of the workpiece.

9. A strengthening method for the strengthening device as described in any one of claims 1-6, characterized in that, The enhancement method includes: When the chamfer angle between the strengthening device and the workpiece meets the predetermined requirements, the workpiece is driven to rotate. The strengthening device is activated to provide ultrasonic vibrations directed at the chamfered surface to strengthen the chamfered surface.

10. The strengthening method of the strengthening device according to claim 9, characterized in that, The predetermined requirements include: The duty cycle of the strengthening device Satisfying the formula: ; The distance between the marks left by the two impacts of the strengthening device Satisfying the formula: .

11. The strengthening method of the strengthening device according to claim 9, characterized in that, The predetermined requirement includes: the rotational speed range of the workpiece is greater than 100 rpm.

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