Symmetrical self-adaptive roll strengthening device

Abstract

The application discloses a symmetrical self-adaptive rolling strengthening device, which comprises a linear pushing mechanism, a rolling cutter mechanism, a main frame and a guide sliding support rod; the main frame is used for combining the whole device together and connecting with a machine tool cutter handle; the linear pushing mechanism is arranged along a vertical direction and is fixedly connected with the main frame; the guide sliding support rod is slidably connected with the linear pushing mechanism along a horizontal direction; two rolling cutter mechanisms are symmetrically arranged on both sides of the guide sliding support rod along the horizontal direction, the middle parts are rotationally connected with the main frame, the upper parts are symmetrically provided with inclined guide grooves, the distance between the upper ends of the two guide grooves is smaller than the distance between the lower ends, and the two sides of the guide sliding support rod are respectively connected with the guide grooves through sub pin shafts to form moving pairs. The rolling cutter mechanism is driven to rotate by the up-down movement of the guide sliding support rod to realize the clamping of a workpiece and the implementation of rolling pressure or the loosening of the workpiece, and the horizontal movement of the guide sliding support rod realizes the self-adaptive centering of the rolling cutter mechanism on both sides of the workpiece, so that the stability of a rolling processing process and the surface strengthening quality are improved.

Description

Technical Field

[0001] This invention relates to the field of rolling processing of aero-engine blades, and more specifically, to a symmetrical adaptive rolling strengthening device. Background Technology

[0002] With the continuous development of aviation technology, new high-hardness lightweight materials are gradually being used in blade manufacturing. Due to the greater difficulty in machining high-hardness lightweight alloys, their increased sensitivity to stress concentration, and their brittle fracture mechanism and anisotropic properties, the fatigue failure problem faced by blades is becoming more prominent. Fatigue failure, as the main failure mode of aero-engine blades, greatly threatens the service life and operational reliability of the engine. Therefore, surface treatment and strengthening treatment of blades after milling are of great significance for improving blade performance.

[0003] Roller burnishing is a smooth, chip-free finishing process. Under the action of rolling pressure, the roller burnishing tool contacts the workpiece surface, causing elastoplastic deformation of the surface metal, generating residual compressive stress on the workpiece surface, and creating a residual stress layer in the subsurface layer, while simultaneously reducing surface roughness. Compared to traditional processes like shot peening and laser impact testing, roller burnishing can better reduce surface roughness and obtain a smoother finished surface while still meeting surface strengthening requirements.

[0004] Invention patent CN114292994A discloses a method for strengthening thin-walled blades by rolling based on low-plasticity polishing. It uses a cemented carbide ball in a hydrostatic bearing as a cutting head, maintaining solid contact with the surface to be polished and allowing it to roll freely in any direction on the workpiece surface, effectively reducing surface deformation and damage caused by tool slippage during rolling. However, this technology uses unilateral rolling, which can easily cause blade profile deformation. Invention patent CN111876570B discloses a robotic machining system for ultrasonic rolling strengthening of blades, combining ultrasonic shot peening with low-plasticity polishing as a novel surface modification technology, which can further reduce blade scratches in traditional rolling. However, this technology relies on high-frequency hammering of a small ball, resulting in lateral slippage friction during the pressing process, still leading to surface scratches. Furthermore, the axial dimension of this ultrasonic rolling device is too large, making symmetrical rolling impossible in the narrow gaps between blades.

[0005] Invention patent CN114107634A discloses a double-sided symmetrical rolling strengthening device based on a diamond hob. The double-sided cutter head can extend to both sides of the blade of the impeller for symmetrical rolling processing, and can achieve adaptive strengthening for blades with varying thickness. However, on the one hand, the transmission mechanism and cutter of this device can only make adaptive adjustments of the same amplitude on both sides according to the blade thickness. However, the blade surface is a complex free-form surface. When the center of its cross-section shifts, the symmetry of the rolling on both sides needs to be controlled by moving the drive mechanism back and forth. This can easily lead to unequal forces on both sides and insufficient stability due to the difficulty in controlling the precision. On the other hand, this device only uses diamond as the cutter head and does not have a lubrication oil circuit. During rolling, sliding friction occurs between the cutter head and the workpiece, which can easily cause scratches.

[0006] Based on domestic and international patents, papers, books and other literature, there is still a lack of a double-sided rolling strengthening device that can be used for blades of narrow-gap bladed disks to achieve adaptive bending of the complex curved surface of the blades. Summary of the Invention

[0007] To address the shortcomings or improvement needs of existing rolling strengthening devices, such as the difficulty in ensuring the symmetry of rolling on both sides and the difficulty in achieving self-adaptation to the complex curved surface of blades, this invention provides a symmetrical adaptive rolling strengthening device. Its purpose is to achieve self-adaptation of rolling on both sides to the changes in the cross-sectional center of the complex curved surface of the blade, reduce the operation difficulty of the control system, and improve the stability of the rolling process and the surface strengthening quality.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A symmetrical adaptive rolling strengthening device is provided, comprising: a linear push mechanism, a rolling cutter mechanism, a main frame, and a guide rod; the main frame is used to assemble the entire device together and connect it to a machine tool holder; the linear push mechanism is arranged vertically and fixedly connected to the main frame, and the guide rod is slidably connected to the linear push mechanism in the horizontal direction; two rolling cutter mechanisms are symmetrically arranged on both sides of the guide rod in the horizontal direction; the middle part of the rolling cutter mechanism is rotatably connected to the main frame, and the upper part of the two rolling cutter mechanisms is symmetrically provided with inclined guide grooves, and the distance between the upper ends of the two guide grooves is less than the distance between the lower ends of the two guide grooves; a secondary pin is fixedly connected to both sides of the guide rod, and the secondary pin passes through the guide groove to form a sliding pair; the guide rod is used to drive the rolling cutter mechanism to rotate around the middle part by moving up and down, thereby clamping the workpiece to apply rolling pressure or releasing it, and is also used to achieve self-adaptation of the two rolling cutter mechanisms on both sides of the workpiece by moving horizontally.

[0010] Preferably, the guide groove includes a first guide groove and a second guide groove that are connected to each other, the second guide groove being located above the first guide groove; the inclination angle between the first guide groove and the vertical direction is α, and the inclination angle between the second guide groove and the vertical direction is β, wherein α is greater than β.

[0011] Preferably, the tilt angle β is less than the friction angle θ, wherein the coefficient of dynamic friction between the auxiliary pin and the guide groove is μ, and the friction angle θ is defined as arctanμ.

[0012] Preferably, the rolling cutter mechanism includes a groove head, a rolling cutter shank, a rolling cutter head, and a rolling cutter cover; the groove head is used to connect the main frame and the guide rod, and the lower part of the groove head is fixedly connected to the rolling cutter shank; the lower part of the rolling cutter shank is provided with a cavity penetrating the rolling cutter shank, the rolling cutter head is placed in the cavity, and the rolling cutter cover is sealed and connected to the rear side of the cavity; an oil passage is provided inside the rolling cutter shank, the oil passage is connected to the upper part of the rolling cutter shank to form an oil inlet, and the oil passage is connected to the cavity at the bottom.

[0013] Preferably, the inner side of the rolling cutter cover is provided with a boss, the boss is provided with a groove, and the groove is connected to the oil passage.

[0014] Preferably, the rolling cutter head includes a rolling tip, a cutter head housing, a pressure-reducing slider, and a cutter head rear cover. The cutter head housing, the pressure-reducing slider, and the cutter head rear cover all have through holes inside. The rolling tip is a cemented carbide ball. The cutter head housing is sealed to the inner wall of the cavity. The inner diameter of the front end of the cutter head housing is smaller than the diameter of the rolling tip. The rolling tip is placed at the front end of the through hole inside the cutter head housing. The cutter head rear cover is inserted into the rear end of the cutter head housing and is detachably connected to it. The pressure-reducing slider is slidably disposed inside the cutter head housing. The pressure-reducing slider is installed behind the rolling tip. The front end of the pressure-reducing slider has a tapered groove. There is a gap between the rear end of the pressure-reducing slider and the front end of the cutter head rear cover. The outer diameter of the rear end of the pressure-reducing slider is larger than the inner diameter of the cutter head rear cover.

[0015] Preferably, the oil inlet is connected to the oil supply device to provide static oil pressure or pulse oil pressure, which is achieved by connecting a high-speed servo valve when providing pulse oil pressure.

[0016] Preferably, the front end of the cutter head housing is provided with an overflow port.

[0017] Preferably, the through hole inside the cutter head housing is divided into a first hole segment and a second hole segment from front to back. The diameter of the first hole segment is smaller than the diameter of the second hole segment. Correspondingly, the pressure relief slider is divided into a first shaft segment and a second shaft segment from front to back. The outer diameter of the first shaft segment is smaller than the outer diameter of the second shaft segment, which is used to limit the forward movement of the pressure relief slider.

[0018] Preferably, the cutter head housing is slidably connected to the inner wall of the cavity, and matching limiting members are provided on the front end of the cavity and the rear end outer wall of the cutter head housing, with a spring provided between the limiting members on the front end of the cavity and the rear end outer wall of the cutter head housing.

[0019] In summary, compared with the prior art, the above-described technical solutions conceived by this invention have the following technical effects:

[0020] 1. The symmetrical adaptive rolling strengthening device proposed in this invention, by setting a guide rod that can be slidably connected to a linear pushing mechanism in the horizontal direction, and two rolling cutter mechanisms symmetrically arranged on both sides of the guide rod in the horizontal direction, enables the two rolling cutter mechanisms to be subjected to horizontal forces of different magnitudes on both sides of the blade when the center of the blade cross section shifts. These forces are transmitted to the guide rod, and the horizontal movement of the guide rod drives the rolling cutter mechanism to rotate around the center, so that the forces on the two rolling cutter mechanisms are rebalanced, realizing adaptive centering of double-sided rolling, improving the stability of the rolling process and the surface strengthening quality;

[0021] 2. The symmetrical adaptive rolling strengthening device proposed in this invention uses a linear push mechanism arranged vertically to drive the guide rod to move up and down. The guide rod is fixedly connected to the secondary pin shaft to control the up and down movement of the secondary pin shaft. It is rotatably connected to the main frame through the middle of two rolling cutter mechanisms. The upper part of the two rolling cutter mechanisms is provided with symmetrical and inclined guide grooves and forms a sliding pair connection with the secondary pin shaft. This can convert the up and down movement of the secondary pin shaft into the rotation of the rolling cutter mechanism. It can control the up and down movement of the guide rod to drive the rolling cutter mechanism to rotate around the middle part, thereby clamping the workpiece to apply rolling pressure or releasing it, realizing the control of rolling of surfaces with different thicknesses.

[0022] 3. The preferred guide groove structure in this invention, by setting the inclination angle β of the second guide groove to be smaller than the inclination angle α of the first guide groove, ensures that when the auxiliary pin slides from the first guide groove into the second guide groove, on the one hand, the rotation amplitude of the rolling tool holder corresponding to the up-and-down movement of the guide slide support is smaller, thus making it suitable for fine-tuning during the formal clamping stage; on the other hand, by setting the inclination angle β of the second guide groove to be smaller than the friction angle θ, the auxiliary pin reaches a friction self-locking state, so no matter how much force the blades exert on the rolling tool mechanism, the rolling tool holder cannot be opened, realizing that the opening and closing of the device can be achieved solely by the drive of the linear push mechanism during the processing, without the need for additional clamping force, thus simplifying the operation process;

[0023] 4. The preferred rolling cutter mechanism of the present invention provides oil pressure by arranging an oil supply device connected to the oil inlet, and provides pulse oil pressure by connecting a high-speed servo valve. At the same time, the pressure reducing slider is set inside the cutter head housing to respond quickly to changes in oil pressure. Thus, by inputting different pulse signal waveforms, the corresponding pulse oil pressure and rolling pressure response waveforms can be obtained, and the magnitude of the rolling pressure can be precisely controlled to obtain the corresponding rolling effect. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a symmetrical adaptive rolling strengthening device provided in an embodiment of the present invention;

[0025] Figure 2 This is a front view of a symmetrical adaptive rolling strengthening device provided in an embodiment of the present invention;

[0026] Figure 3 This is a left view of a symmetrical adaptive rolling strengthening device provided in an embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of the groove head structure in a symmetrical adaptive rolling strengthening device provided in an embodiment of the present invention;

[0028] Figure 5 This is a cross-sectional schematic diagram (FF) of the structure of the rolling tool holder, rolling tool head, and rolling tool cover in a symmetrical adaptive rolling strengthening device provided in an embodiment of the present invention.

[0029] Figure 6 This is a partially enlarged cross-sectional schematic diagram (FF) of the rolling cutter head in a symmetrical adaptive rolling strengthening device provided in an embodiment of the present invention;

[0030] Figure 7 This is a schematic diagram of a symmetrical adaptive rolling strengthening device with a hidden symmetrical structure on one side, provided in an embodiment of the present invention.

[0031] Figure 8 This is a schematic diagram of the structure of the rolling blade cover in a symmetrical adaptive rolling strengthening device provided in an embodiment of the present invention;

[0032] Figure 9 This is a schematic diagram of the force on the auxiliary pin shaft in the guide groove in a symmetrical adaptive rolling strengthening device provided by an embodiment of the present invention;

[0033] Figure 10 This is a front view of a symmetrical adaptive rolling strengthening device clamping a blade according to an embodiment of the present invention;

[0034] Figure 11This is a partially enlarged schematic diagram of the rolling cutter head when clamping a blade in a symmetrical adaptive rolling strengthening device provided in an embodiment of the present invention;

[0035] Figure 12 This is an example of the type of pulse signal input during the pulse rolling process in this invention;

[0036] Figure 13 This is a diagram showing the input square wave signal and the step response of the valve core displacement during the pulse rolling process in this invention.

[0037] Figure 14 This is a diagram showing the input square wave signal, hydraulic oil pressure response, and tool tip rolling force response during the pulse rolling process in this invention.

[0038] Figure 15 This is a schematic diagram showing the relative positions of the components of the rolling cutter head during the hydrostatic rolling process in this invention;

[0039] Figure 16 This is a schematic diagram showing the relative positions of the components of the rolling cutter head during the pulse rolling process in this invention;

[0040] Figure 17 This is a schematic diagram showing the relative positions of the components of the rolling cutter head under high pressure during the pulse rolling process in this invention;

[0041] Figure 18 This is a schematic diagram showing the relative positions of the components of the rolling cutter head under low pressure during the pulse rolling process in this invention.

[0042] Figure 19 This is a simplified geometric diagram of a symmetrical adaptive rolling strengthening device structure provided in an embodiment of the present invention;

[0043] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0044] 1-Spindle tool holder, 2-Upper top plate, 3-Guide slide support rod, 4-Slide groove head, 5-Rolling tool holder, 6-Rolling tool cover, 7-Rolling tool head, 8-Thin cylinder, 9-Support frame, 10-Guide slide head, 11-Support bar, 12-Lower base plate, 13-Main pin, 14-Secondary pin, 15-Sealing ring, 16-Spring, 101-Rolling bearing, 102-C-key, 201-Keyway, 301-Guide slide groove, 302-Guide slide pin hole, 40 1-First guide groove, 402-Connecting hole, 403-Main pin hole, 404-Second guide groove, 501-Counterhead threaded hole, 502-Main oil passage, 503-Oil inlet, 504-Secondary oil passage, 601-Boss, 602-Sealing groove, 701-Rolling tip, 702-Cutting head housing, 703-Pressure relief slider, 704-Cutting head rear cover, 801-First air filling and venting hole, 802-Second air filling and venting hole, Push rod-803; Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0046] In embodiments of the present invention, such as Figure 1 As shown, the symmetrical adaptive rolling strengthening device includes a linear push mechanism, such as a thin cylinder 8, a rolling cutter mechanism, a main frame, and a guide rod 3. The main frame is used to assemble the entire device and connect it to the machine tool holder. For ease of observation of the device structure in this embodiment, Figure 2 The front view of the device in this embodiment is shown. Figure 3 A left view of the device in this embodiment is shown. Figure 7 This diagram illustrates the hidden symmetrical structure of this embodiment. A thin cylinder 8 is arranged vertically and fixedly connected to the main frame; a guide rod 3 is slidably connected to the thin cylinder 8 horizontally; two rolling cutter mechanisms are symmetrically arranged on both sides of the guide rod 3 horizontally; the middle of the rolling cutter mechanism is rotatably connected to the main frame, and the upper parts of the two rolling cutter mechanisms are symmetrically provided with inclined guide grooves, with the distance between the upper ends of the two guide grooves being less than the distance between the lower ends of the two guide grooves. A secondary pin 14 is fixedly connected to both sides of the guide rod 3, and the secondary pin 14 passes through the guide groove to form a sliding pair, thereby converting the up-and-down movement of the secondary pin 14 into the rotational movement of the rolling cutter mechanism.

[0047] The thin cylinder 8 is provided with a first inflation / exhaust port 801 and a second inflation / exhaust port 802. The first inflation / exhaust port 801 is connected to the upper sealing cavity of the piston of the thin cylinder 8, and the second inflation / exhaust port 802 is connected to the lower sealing cavity of the piston of the thin cylinder 8. When the first inflation / exhaust port 801 is inflated, the piston of the thin cylinder 8 is in a contracted state, the auxiliary pin 14 moves downward relative to the guide groove, driving the upper ends of the two rolling cutter mechanisms to rotate towards each other and the lower ends to rotate in opposite directions, thus releasing the device. When the second inflation / exhaust port 802 is inflated, the piston of the thin cylinder 8 is in an extended state, the auxiliary pin 14 moves upward relative to the guide groove, driving the upper ends of the two rolling cutter mechanisms to rotate in opposite directions and the lower ends to rotate in opposite directions, thus clamping the device.

[0048] During the roll forming process, on the one hand, the pressure of the thin cylinder 8 controls the guide rod 3 to move up and down, driving the roll forming mechanism to rotate around the center, thereby clamping the workpiece to apply roll forming pressure or releasing it; on the other hand, when the center of the blade section shifts, the two roll forming mechanisms are subjected to horizontal forces of different magnitudes on both sides of the blade, which are transmitted to the guide rod 3. Then, the horizontal movement of the guide rod 3 drives the roll forming mechanism to rotate around the center, so that the forces on the two roll forming mechanisms are rebalanced, achieving adaptive centering of double-sided roll forming.

[0049] In some embodiments, the main frame includes an upper top plate 2, a support frame 9, a support bar 11, and a lower bottom plate 12, which are fixedly connected by bolts to form a frame structure of the main frame. A spindle tool holder 1 is provided at the upper end of the main frame, and the upper end of the spindle tool holder 1 is connected to a machine tool tool holder. The lower end of the spindle tool holder 1 is fastened to the upper end of the upper top plate 2 by screws. C-keys 102 are provided on both sides of the spindle tool holder 1, and keyways 201 are provided on both sides of the upper top plate 2. The C-keys 102 and keyways 201 cooperate to form a circumferential movement limiting structure to prevent relative rotation between the upper top plate 2 and the spindle tool holder 1. The upper top plate 2 is fixedly connected to the support frame 9 by four bolts, realizing stable control of the device of the present invention by the machine tool.

[0050] Specifically, the lower base plate 12 has a groove in its center, and the bottom of the thin cylinder 8 is placed in the groove in the center of the lower base plate 12. The middle of both sides of the thin cylinder 8 are fastened to the support bar 11 by bolts. The support bar 11 is connected to the support frame 9, thereby fixing it to the main frame. The head of the push rod 803 of the thin cylinder 8 is fastened to the guide slide head 10 by four threads. The up and down movement of the guide slide head 10 can be controlled by the pressure change of the thin cylinder 8. The guide slide support rod 3 is arranged on the side horizontal with the guide slide head 10. The middle of the inner side of the guide slide support rod 3 has a guide slide groove 301 in the horizontal direction. The guide slide support rod 3 is slidably connected to the guide slide head 10 by two rolling bearings 101. That is, one end of the rolling bearing 101 is placed in the guide slide head 10, and the other end is placed in the guide slide groove 301, so as to ensure that the guide slide support rod 3 can slide freely in the direction horizontal with the guide slide head 10.

[0051] Furthermore, two guide rods 3 can be symmetrically arranged on the front and rear sides of the guide head 10. The two guide rods 3 are slidably connected to the guide head 10 through two rolling bearings 101, which can make the device more balanced in terms of force.

[0052] In some embodiments, the rolling cutter mechanism includes a groove head 4, a rolling cutter handle 5, a rolling cutter head 7, and a rolling cutter cover 6. The upper part of the groove head 4 is provided with a guide groove, and guide pin holes 302 are respectively opened at both ends of the guide support rod 3. The auxiliary pin shaft 14 is interference-fitted with the guide pin holes 302 to ensure that the guide support rod 3 will not disengage. The auxiliary pin shaft 14 passes through the guide groove to form a sliding pair. The middle part of the groove head 4 is provided with a main pin hole 403, which is hinged to the support frame 9 via the main pin shaft 13 to achieve a rotatable connection. The lower part of the groove head 4 is provided with a connecting hole 402, which is fastened to the rolling cutter handle 5 with screws. Figure 4 As shown. The guide groove includes a first guide groove 401 and a second guide groove 404 that are connected to each other. The second guide groove 404 is located above the first guide groove 401. The angle of inclination of the first guide groove 401 with the vertical direction is α, and the angle of inclination of the second guide groove 404 with the vertical direction is β, where α is greater than β.

[0053] This structure enables two stages of controlling the rotation of the rolling tool holder 5 through air pressure changes: when the secondary pin 14 passes through the first guide groove 401, the rotation amplitude of the rolling tool holder 5 corresponding to the up-and-down movement of the guide rod 3 is relatively large due to the relatively large tilt angle α, which is suitable for rapid closure in the initial clamping stage; when the secondary pin 14 passes through the second guide groove 404, the rotation amplitude of the rolling tool holder 5 corresponding to the up-and-down movement of the guide rod 3 is relatively small due to the relatively small tilt angle β, which is suitable for fine-tuning in the formal clamping stage.

[0054] Optionally, the tilt angle β is less than the friction angle θ, where the coefficient of dynamic friction between the secondary pin 14 and the guide groove is μ, and the friction angle θ is defined as arctanμ. This structure enables the secondary pin 14 to reach a friction self-locking state when it passes through the second guide groove 404. That is, no matter how much force the blades exert on the rolling cutter mechanism, the rolling cutter shank 5 cannot be opened. This allows the device to open and close solely through the linear drive mechanism during processing, without the need for additional clamping force, thus simplifying the operation.

[0055] Specifically, the lower part of the rolling tool holder 5 has a cavity penetrating the rolling tool holder 5, and the rolling tool head 7 is placed in the cavity, such as... Figure 5 As shown. The upper part of the roller burnishing tool holder 5 is provided with a countersunk threaded hole 501. The lower part of the countersunk threaded hole 501 is connected to the main oil passage 502. The countersunk threaded hole 501 and the corresponding size screw are sealed and fixed by thread sealant to prevent hydraulic oil from leaking out. The rear of the upper end of the roller burnishing tool holder 5 is provided with a protrusion. The protrusion has an oil inlet 503, which is connected to the hydraulic oil line to provide hydraulic oil. The lower end of the main oil passage 502 has a secondary oil passage 504. The secondary oil passage 504 connects the main oil passage 502 and the lower cavity of the roller burnishing tool holder 5, which can guide hydraulic oil into the roller burnishing head 7.

[0056] Specifically, the roller burnisher cover 6 has a sealing groove 602 on the side facing the cavity, and a sealing ring 15 is provided in the sealing groove 602. The roller burnisher cover 6 is fixed to the rear end of the roller burnisher handle 5 by four screws, achieving a fixed and sealed connection with the roller burnisher handle 5 to prevent hydraulic oil from leaking out from the rear end of the roller burnisher handle 5. The roller burnisher cover 6 also has a boss 601 on the side facing the cavity, which is used to limit the stroke of the roller burnisher head 7; the boss 601 has a slot, which is connected to the oil passage to ensure that the hydraulic oil flowing in from the auxiliary oil passage 504 can flow smoothly into the roller burnisher head 7, such as Figure 8 As shown.

[0057] Specifically, the rolling cutter head 7 includes a rolling cutter tip 701, a cutter head housing 702, a pressure reducing slider 703, and a cutter head rear cover 704. The cutter head housing 702 is sealed to the inner wall of the cavity. Figure 6 As shown. The cutter head housing 702, the pressure-reducing slider 703, and the cutter head rear cover 704 all have through holes to ensure smooth flow of hydraulic oil into the burnishing cutter head 7. The burnishing tip 701 is a carbide ball placed at the front end of the through hole inside the cutter head housing 702. The inner diameter of the front end of the cutter head housing 702 is smaller than the diameter of the burnishing tip 701, allowing the burnishing tip 701 to roll freely at the front end without falling out. The pressure-reducing slider 703 is installed behind the burnishing tip 701 and can slide back and forth inside the cutter head housing 702. The front end of the pressure-reducing slider 703 has a tapered groove, which ensures stable contact with the burnishing tip 701. The central through hole of the pressure-reducing slider 703 is a throttling orifice. The front end of the throttling orifice has a front cavity that communicates with the tapered groove, and the rear end of the throttling orifice has a rear tapered cavity for guiding hydraulic oil. The pressure-reducing slider 703 transmits hydraulic oil pressure to the rolling cutter tip 701 and the cutter head housing 702. Simultaneously, it reduces pressure through a throttling orifice, preventing excessive hydraulic oil overflow and waste. The pressure-reducing slider 703 is made of brass, or other wear-resistant, low-hardness materials; this is not limited. The cutter head rear cover 704 is installed behind the pressure-reducing slider 703. Its outer surface is threaded, engaging with the threaded hole at the rear end of the cutter head housing 702. The outer diameter of the rear end of the pressure-reducing slider 703 is larger than the inner diameter of the cutter head rear cover 704 to prevent it from falling out from behind the cutter head housing 702. Furthermore, a gap exists between the rear end of the pressure-reducing slider 703 and the front end of the cutter head rear cover 704 to allow the pressure-reducing slider 703 and the rolling cutter tip 701 to move back and forth within the cavity gap.

[0058] Optionally, the front end of the cutter head housing 702 is provided with an overflow port, which can drain excess hydraulic oil and prevent the front end of the cutter head housing 702 from being crushed.

[0059] Optionally, the through hole inside the cutter head housing 702 is divided into a first hole section and a second hole section from front to back. The diameter of the first hole section is smaller than the diameter of the second hole section. Correspondingly, the pressure reducing slider 703 is divided into a first shaft section and a second shaft section from front to back. The outer diameter of the first shaft section is smaller than the outer diameter of the second shaft section. Its function is to limit the forward movement of the pressure reducing slider 703 when the rear oil pressure is too high and the rolling cutter tip 701 is unloaded, so as to prevent the pressure reducing slider 703 from directly applying pressure to the rolling cutter tip 701, thereby causing the front end of the cutter head housing 702 to be crushed.

[0060] Optionally, the cutter head housing 702 is slidably connected to the inner wall of the cavity, and matching limiting members are provided on the front end of the cavity and the rear end outer wall of the cutter head housing 702. A spring 16 is provided between the limiting members on the front end of the cavity and the rear end outer wall of the cutter head housing 702 to ensure that the rolling cutter head 7 can extend and retract normally in the cavity.

[0061] Optionally, the oil inlet 503 is connected to the oil supply device to provide static oil pressure or pulse oil pressure. When providing pulse oil pressure, it is achieved through a pulse valve, oil cylinder, self-excited vibration or other means. The method of providing pulse oil pressure is not limited here.

[0062] The following describes the working principle of the functions achieved by this embodiment:

[0063] (1) Surface Adaptive Principle:

[0064] During the rolling process, when the blade cross-section thickens, the rolling tip 701 experiences a greater thrust from the workpiece than the rolling force. This initially causes the rolling tip 701 to push the pressure-reducing slider 703 backward. When the pressure-reducing slider 703 contacts the cutter head cover 704 and is blocked, it continues to push the cutter head housing 702 and the cutter head housing 702 backward, increasing the gap between the two symmetrical rolling cutter heads 7 to accommodate the increased blade thickness. When the blade cross-section thins, the rolling tip 701 experiences a lesser thrust from the workpiece than the rolling force. The hydraulic pressure pushes the pressure-reducing slider 703 forward until it is blocked at the stepped hole of the cutter head housing 702. This continues to push the cutter head housing 702 and the cutter head housing 702 forward, decreasing the gap between the two symmetrical rolling cutter heads 7 to accommodate the decreased blade thickness.

[0065] However, because the blade surface is a complex freeform surface, as the rolling process proceeds, the center of the blade section will shift relative to the center of the two symmetrically arranged rolling cutter tips 701. For example, when the blade... Figure 10 , Figure 11When the blade bulges to the right, if the machine tool holder drives the entire rolling device upward, the elastic force of the blade on the right rolling head 7 will be greater than the rolling force, causing the head housing 702 to move backward. When it reaches the boss 601 of the rolling cover 6, it can no longer move. Because the blade bulges outward to the right, the elastic force on the left rolling tip 701 will be less than the rolling force. At this time, the horizontal forces applied to the guide rod 3 by the two auxiliary pins 14 will be different. In this embodiment, the horizontal force on the right side will be greater than that on the left side, causing the guide rod 3 to move slightly to the left horizontally relative to the guide head 10 through the rolling bearing 101, driving the rolling handles 5 on both sides to rotate counterclockwise until the horizontal force on the guide rod 3 is balanced again. Therefore, even if the center of the blade cross-section is deflected, or the alignment control of the device during the processing is not accurate enough, the device can stably complete the rolling process and has strong adaptability.

[0066] (2) Clamping and self-locking principle

[0067] When the second inflation / exhaust port 802 of the thin cylinder 8 is inflated, the piston of the thin cylinder 8 is extended, providing thrust. The guide head 10, fixed to the push rod 803 of the thin cylinder 8, pushes the guide support rod 3 upward. Since the guide groove 301 of the guide support rod 3 cooperates with the two rolling bearings 101 of the guide head 10, the guide support rod 3 remains horizontal during the upward movement. At the same time, the guide support rod 3 drives the auxiliary pins 14 on both sides to move upward. Under the force of the auxiliary pins 14, the upper surface of the first guide groove 401 of the sliding head 4 on both sides is driven by the normal contact force to rotate the sliding head 4 outward around the main pin 13, thereby driving the rolling tool holders 5 on both sides to rotate towards each other around the main pin 13, completing the clamping action.

[0068] In the first stage of clamping, the secondary pin 14 slides in the first guide groove 401. In this embodiment, the first guide groove 401 has an inclination angle α of 30° with the vertical direction, and the coefficient of dynamic friction between the secondary pin 14 and the sliding head 4 is 0.2. At this time, when the secondary pin 14 moves upward a certain distance, the rolling tool holder 5 will rotate at a large amplitude, so it can be used for rapid closure in the initial clamping stage. If the rolling tool tip 701 is pushed open by an external force F, the external force F is transmitted to the first guide groove 401, which will form a normal force FN on the secondary pin 14, such as... Figure 9As shown, the normal force FN can be decomposed into force Fl and force Ft along the horizontal direction and tangentially along the first guide groove 401. At this time, the auxiliary pin 14 is also subjected to the frictional force f generated by the first guide groove 401, which is opposite in direction to Ft. The forces Fl on both sides can be canceled by the guide rod 3 connected to the auxiliary pin 14, while the force Ft needs to be counteracted by the frictional force f and the upward thrust of the thin cylinder 8. Since the friction angle θ is arctan0.2=11.3° and the inclination angle α=30°, θ<α, the maximum static friction between the auxiliary pin 14 and the first guide groove 401 is insufficient to resist the tangential component force Ft. When the external force F is large enough, the slide head 4 will force the auxiliary pin 14 to move downward along the first guide groove 401, so that the push rod 803 of the thin cylinder 8 is pressed back. In the first stage of clamping, as the thin cylinder 8 pushes upward, the angle α will continuously decrease, but will always be greater than the angle θ. Therefore, during the entire first stage of clamping, the rolling tool holder 5 can be opened by external force.

[0069] In the second stage of clamping, the auxiliary pin 14 slides in the second guide groove 404. In this embodiment, the inclination angle β between the second guide groove 404 and the horizontal plane is 5°. When the auxiliary pin 14 moves upward a short distance, the rolling tool holder 5 will rotate very slightly, which can be used for the slow closing in the final clamping stage. At this time, if the tool tip is subjected to an external force F that pushes it open, since θ>β, the maximum static friction between the auxiliary pin 14 and the second guide groove 404 is sufficient to resist the tangential component force Ft, achieving a frictional self-locking state. Therefore, in the second stage of clamping, the rolling tool holder 5 can only be opened by inflating through the first inflation and deflation hole 801. No matter how large the external force F acting on the tool tip is, it cannot open the rolling tool holder 5, thus achieving the self-locking function of the device.

[0070] (3) Static pressure and pulse rolling principle:

[0071] During the rolling process, high-pressure hydraulic oil pumped by the oil supply device flows into the rolling head 7 through the oil inlet 503 of the rolling tool holder 5, along the main oil passage 502 and the auxiliary oil passage 504. At this time, the pressure of the high-pressure hydraulic oil acts on the pressure reducing slider 703 and the head housing 702, pushing the head housing 702 forward, causing the rolling head 7 to extend outward, and pushing the pressure reducing slider 703 forward, causing the rolling tip 701 to move to the front end. When the pressure reducing slider 703 reaches the stepped hole of the head housing 702, it stops pushing the rolling tip 701. At this time, static oil pressure is transmitted, pushing the head housing 702. When the rolling tip 701 first contacts the workpiece surface, the pressure reducing slider 703 behind it can no longer move forward. At this time, the head housing 702 and the rear cover 704 move forward relative to the pressure reducing slider 703 until the rear cover 704 contacts the rear end face of the pressure reducing slider 703 and then stops moving. Figure 15As shown, at this time, the rolling cutter tip 701 is subjected to the static pressure of high pressure hydraulic oil on the pressure reducing slider 703 and the cutter head housing 702. The high pressure hydraulic oil lubricates the cutter tip after passing through the throttling hole of the pressure reducing slider 703 and is discharged from the overflow port and the front gap of the cutter head housing 702. This process is the static pressure rolling process.

[0072] During the pulse rolling process, the pulse hydraulic pressure can be provided by a pulse valve, hydraulic cylinder, self-excited vibration, or other methods, and is not limited here. In this embodiment, the pulse hydraulic pressure is achieved through a high-speed servo valve. The existing valve is the Yuken LSVG-03, and the expected frequency can reach 300Hz. The pulse signal can be a square wave, sawtooth wave, sine wave, etc. Figure 12 As shown. In this embodiment, when the pulse oil pressure in the oil supply device is activated, the high-speed servo valve converts the input high-frequency voltage signal into the displacement of the high-speed servo valve core, and the pulse change is as follows. Figure 13 As shown; the valve core displacement generates pulsed oil pressure, which in turn generates pulsed rolling force, as shown. Figure 14 As shown. Because the average pressure of the pulsed oil pressure is less than the working pressure under static pressure, the cutter head housing 702 will retract a certain distance under the action of the spring 1616, as... Figure 16 As shown; within a short period of time, the hydraulic oil pressure reaches its peak, and the rolling force of the rolling tool tip 701 increases significantly, causing slight deformation of the workpiece surface, such as... Figure 17 As shown. Due to its large mass and the presence of the internal spring 16, the cutter head housing 702 cannot respond quickly to rapid changes in hydraulic oil pressure. In contrast, the pressure-reducing slider 703 has a smaller mass and can slide freely within the cavity gap, allowing it to respond quickly to oil pressure changes, undergoing a small displacement, and transmitting the peak pressure to the rolling cutter tip 701. When the hydraulic oil pressure reaches its lowest point, the rolling force of the rolling cutter tip 701 drops significantly. At this time, the elasticity of the workpiece surface is greater than the rolling force, such as... Figure 18 As shown, the workpiece rapidly undergoes elastic recovery, forcing the rolling tool tip 701 and the pressure-reducing slider 703 to shift slightly backward, returning to their initial positions. At this time, the rolling force of the rolling tool tip 701 is close to zero, and the abrasive residue remaining between the rolling tool tip 701, the tool head housing 702, and the workpiece surface can be promptly discharged. This process constitutes one pulse rolling cycle in the pulse rolling process.

[0073] Since the roller burnishing tip 701 can only move back and forth within the roller burnishing head 7, its corresponding roller burnishing force is only in the back-and-forth direction. Under conditions of sufficient lubrication and no grinding, there is almost no tangential roller burnishing force, thus eliminating surface scratches or other defects caused by tangential forces. By using different input signal waveforms, different pulse oil pressure and roller burnishing force response waveforms can be obtained, allowing for precise control of the roller burnishing force under different roller burnishing conditions and improving the roller burnishing quality under various conditions.

[0074] The calculation method for the applicable blade size range of this device is as follows:

[0075] like Figure 19 As shown, l0 represents the distance between the two main pins 13, l1 represents the distance between the two auxiliary pins 14, l2 represents the length of the first guide groove 401, l3 represents the distance from the bottom of the second guide groove 404 to the main pin 13, l4 represents the length of the rolling tool holder 5, l5 represents the vertical distance from the rolling tool tip 701 to the rolling tool holder 5, h represents the vertical distance from the guide rod 3 to the line connecting the two main pins 13; θ represents the angle between the second guide groove 404 and the line connecting the two main pins 13, θ1 represents the angle between the first guide groove 401 and the second guide groove 404, θ2 represents the angle between the first guide groove 401 and the line connecting the main pins 13, θ3 represents the angle between the rolling tool holder 5 and the line connecting the second guide groove 404 and the main pin 13, α1 and α2 represent the angles between the left and right rolling tool holders 5 and the lines connecting the main pins 13, respectively, δ x This indicates the center offset distance between the two rolling tool tips 701.

[0076] To ensure the rolling device can treat all blades, the maximum length of the blade must be less than the length l4 of the rolling cutter shank 5. This restriction does not apply if only the edge area of ​​the blade needs to be strengthened. When strengthening the blades of the impeller disk, the minimum distance between the blades must be less than the thickness of the rolling cutter head 7.

[0077] To ensure the mechanism can self-lock and open and close normally throughout the rolling hardening process, the maximum angle θ should not exceed 90°. Using this as a constraint, the maximum allowable center deflection distance δ of the device can be calculated. x .

[0078] Among them, the parameters α1 and α2 can be obtained from equation (1), where h0 and x0 are intermediate variables for calculation.

[0079]

[0080] Substituting the obtained α1 and α2 into Equation 2, we can obtain the variable δ. x :

[0081]

[0082] Therefore, the applicable blade profile must satisfy the requirement that the maximum offset distance of the blade section center is less than δ. x .

[0083] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A symmetrical adaptive rolling strengthening device, characterized in that, include: The device comprises a linear push mechanism, a rolling cutter mechanism, a main frame, and a guide rod (3). The main frame is used to assemble the entire device together and connect it to the machine tool spindle shank (1). The linear push mechanism is arranged vertically and fixedly connected to the main frame. The guide rod (3) is slidably connected to the linear push mechanism in the horizontal direction. The two rolling cutter mechanisms are symmetrically arranged on both sides of the guide rod (3) in the horizontal direction. The middle part of the rolling cutter mechanism is rotatably connected to the main frame. The upper part of the two rolling cutter mechanisms is symmetrically provided with inclined guide grooves, and the distance between the upper ends of the two guide grooves is less than the distance between the lower ends of the two guide grooves. The two sides of the guide rod (3) are respectively fixedly connected with auxiliary pins (14). The auxiliary pins (14) pass through the guide grooves to form a sliding pair. The guide rod (3) is used to drive the rolling cutter mechanism to rotate around the middle part by moving up and down, thereby clamping the workpiece and applying rolling pressure or releasing it. It is also used to achieve self-adaptation of the two rolling cutter mechanisms on both sides of the workpiece by moving horizontally.

2. The symmetrical adaptive rolling strengthening device as described in claim 1, characterized in that, The guide groove includes a first guide groove (401) and a second guide groove (404) that are connected to each other. The second guide groove (404) is located above the first guide groove (401). The first guide groove (401) has an inclination angle of α with the vertical direction, and the second guide groove (404) has an inclination angle of β with the vertical direction, where α is greater than β.

3. The symmetrical adaptive rolling strengthening device as described in claim 2, characterized in that, The tilt angle β is less than the friction angle θ, where the coefficient of dynamic friction between the secondary pin (14) and the guide groove is μ, and the friction angle θ is defined as arctanμ.

4. The symmetrical adaptive rolling strengthening device according to any one of claims 1 to 3, characterized in that, The rolling cutter mechanism includes a grooving head (4), a rolling cutter shank (5), a rolling cutter head (7), and a rolling cutter cover (6); the grooving head (4) is used to connect the main frame and the guide rod (3), and the lower part of the grooving head (4) is fixedly connected to the rolling cutter shank (5); the lower part of the rolling cutter shank (5) is provided with a cavity penetrating the rolling cutter shank (5), the rolling cutter head (7) is placed in the cavity, and the rolling cutter cover (6) is sealed and connected to the rear side of the cavity; the rolling cutter shank (5) is provided with an oil passage, the oil passage is connected to the upper part of the rolling cutter shank (5) to form an oil inlet (503), and the oil passage is connected to the cavity.

5. The symmetrical adaptive rolling strengthening device as described in claim 4, characterized in that, The inner side of the rolling cutter cover (6) is provided with a boss (601), the boss (601) is provided with a slot, and the slot is connected to the oil passage.

6. The symmetrical adaptive rolling strengthening device as described in claim 4, characterized in that, The rolling cutter head (7) includes a rolling cutter tip (701), a cutter head housing (702), a pressure reducing slider (703), and a cutter head rear cover (704). The cutter head housing (702), the pressure reducing slider (703), and the cutter head rear cover (704) all have through holes. The rolling cutter tip (701) is a cemented carbide ball. The cutter head housing (702) is sealed to the inner wall of the cavity. The inner diameter of the front end of the cutter head housing (702) is smaller than the diameter of the rolling cutter tip (701). The rolling cutter tip (701) is placed at the front end of the through hole inside the cutter head housing (702). The cutter head rear cover (704) is inserted into the rear end of the cutter head housing (702) and is detachably connected to the cutter head housing (702); the pressure reducing slider (703) is slidably disposed inside the cutter head housing (702), the pressure reducing slider (703) is installed on the rear side of the rolling cutter tip (701), the front end of the pressure reducing slider (703) is provided with a tapered groove, the rear end of the pressure reducing slider (703) has a gap with the front end of the cutter head rear cover (704), and the outer diameter of the rear end of the pressure reducing slider (703) is larger than the inner diameter of the cutter head rear cover (704) for responding to static pressure or pulse oil pressure.

7. The symmetrical adaptive rolling strengthening device as described in claim 4, characterized in that, The oil inlet (503) is connected to the oil supply device and is used to provide static oil pressure or pulse oil pressure. When providing pulse oil pressure, it is achieved through a pulse valve, oil cylinder or self-excited vibration.

8. The symmetrical adaptive rolling strengthening device as described in claim 6, characterized in that, The front end of the cutter head housing (702) is provided with an overflow port.

9. The symmetrical adaptive rolling strengthening device as described in claim 6, characterized in that, The through hole inside the cutter head housing (702) is divided into a first hole section and a second hole section from front to back. The diameter of the first hole section is smaller than the diameter of the second hole section. Correspondingly, the pressure relief slider (703) is divided into a first shaft section and a second shaft section from front to back. The outer diameter of the first shaft section is smaller than the outer diameter of the second shaft section, which is used to limit the forward movement of the pressure relief slider (703).

10. The symmetrical adaptive rolling strengthening device as described in claim 6, characterized in that, The cutter head housing (702) is slidably connected to the inner wall of the cavity. Matching limiting members are provided on the front end of the cavity and the rear end outer wall of the cutter head housing (702). A spring (16) is provided between the limiting members on the front end of the cavity and the rear end outer wall of the cutter head housing (702).

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