A top-pressure shaping tooling and method for irregular cross-section thin-walled castings

Abstract

This invention relates to a top-pressure shaping fixture and method for irregular cross-section thin-walled castings, belonging to the technical field of thin-walled casting shaping, and solves the technical problems of insufficient shaping force, shaping range, and versatility of existing top-pressure shaping devices. The fixture includes a top-pressure shaping device, a rear-end drive device, and a high-frequency vibration device. The top-pressure shaping device includes a drive component, a transmission component, a cast iron top-pressure head, a support frame, a heat source, and a mounting frame. The heat source, drive component, transmission component, and cast iron top-pressure head are integrated on the support frame. The rear-end drive device is connected to both the support frame and the mounting frame to adjust the position of the support frame on the mounting frame. During shaping, the casting to be shaped is fixed on the mounting frame. The heat source controls the deformation of the drive component to compress the transmission component, which in turn drives the cast iron top-pressure head to compress and shape the casting surface. This achieves precise control over the magnitude of the applied force and the shaping range, and is convenient to use.

Description

Technical Field

[0001] This invention relates to the field of thin-walled casting straightening technology, and in particular to a top-pressure straightening tooling and method for thin-walled castings with irregular cross-sections. Background Technology

[0002] Currently, there are two methods for straightening irregular cross-section thin-walled castings with cavities. One method is manual straightening using hammering devices, which is time-consuming, labor-intensive, and inefficient. The other method is straightening using a top press. Existing top presses generally use hydraulic devices or gear transmission mechanisms for straightening. This type of top press has a complex structure, and the hydraulic device or gear transmission device, as the driving device, inevitably requires corresponding pipelines or motors, making the top press relatively bulky. For the requirement of straightening from the inside out, the existing technology is difficult to operate, and it is even more difficult to control the deformation during straightening. Summary of the Invention

[0003] Based on the above analysis, the present invention aims to provide a top-pressure straightening fixture and method for irregular cross-section thin-walled castings, in order to solve the problems of existing top-pressure straightening devices having weak straightening force, straightening capacity, and versatility, making it difficult to operate for straightening from the inside out, and even more difficult to control the deformation during straightening.

[0004] On one hand, embodiments of the present invention provide a top-pressure straightening fixture for thin-walled castings with irregular cross-sections, including a top-pressure straightening device, a rear-end drive device, and a high-frequency vibration device for eliminating stress in local straightening areas of the casting;

[0005] The top-pressure calibration device includes a driving component, a transmission component, a cast iron top-pressure head, a support frame, a heat source, and a mounting frame. The heat source, driving component, transmission component, and cast iron top-pressure head are integrated on the support frame.

[0006] The rear drive device is connected to the support frame and the mounting frame respectively, and is used to adjust the position of the support frame on the mounting frame;

[0007] During the calibration process, the casting to be calibrated is fixed on the mounting frame, and the heat source control drive component and the deformation extrusion transmission component drive the cast iron top pressure head to extrude and calibrate the casting surface through the transmission component.

[0008] Based on further improvements to the above-mentioned device, the working end of the high-frequency vibration device contacts the outer surface of the casting correction part, and performs high-frequency vibration treatment on the casting correction part.

[0009] Based on further improvements to the above-mentioned device, the rear drive device includes a direction adjustment support, a double-column hydraulic arm, and a worm gear;

[0010] One end of the direction adjustment support is connected to the mounting frame, and the other end is fixedly connected to the double-column hydraulic arm;

[0011] One end of the dual-column hydraulic arm is fixedly connected to the direction adjustment support seat, and the other end is fixedly connected to the worm gear.

[0012] One end of the worm gear is fixedly connected to the double-column hydraulic arm, and the other end is connected to the support frame.

[0013] Based on further improvements to the above device, the dual-column hydraulic arm is a primary transmission device, and the worm gear is a secondary transmission device.

[0014] The extension and retraction direction of the worm gear is consistent with the extension and retraction direction of the double-column hydraulic arm.

[0015] Based on further improvements to the above-mentioned device, the mounting frame includes a vertical support rod, a height-fixing ring, and a cast support beam;

[0016] The direction adjustment support is mounted on a height-fixing ring, and the height-fixing ring is mounted on a vertical support rod.

[0017] The position of the height-fixing ring on the vertical support rod is adjustable.

[0018] Based on further improvements to the above-mentioned device, the deformation state of the driving component varies at different temperatures.

[0019] Based on a further improvement of the above device, the driving element is a conductor, and the heat source includes a power supply component that transmits current to the inside of the driving element.

[0020] When the drive component is powered on, its shape changes with the internal temperature of the drive component.

[0021] Based on further improvements to the above device, the driving component is made of Ni / Ti bidirectional shape memory alloy and has a spiral shape, which provides push-out force through deformation.

[0022] Based on further improvements to the above device, a rear-end temperature-measuring thermocouple is also provided on the support frame for measuring the temperature of the drive component.

[0023] On one hand, embodiments of the present invention provide a method for top-pressing and straightening of thin-walled castings with irregular cross-sections, including using the aforementioned top-pressing and straightening fixture for thin-walled castings with irregular cross-sections to straighten the castings.

[0024] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0025] 1. This invention adjusts the position of the support frame through the rear drive device, which can conveniently adjust the cast iron top pressure head to the surface of the casting to be shaped. Then, the heat source controls the drive component to change its shape to squeeze the transmission component. The transmission component drives the cast iron top pressure head to move, thereby realizing the shaping of the casting. The structure is simple and does not require a complex mechanical force transmission mechanism, making the top pressure shaping device small and lightweight.

[0026] 2. By controlling the temperature parameters of the driving component and the deformation amount of the driving component, the amount of single-time correction can be controlled to adapt to different deformation parts. In addition, the size of the cast iron top pressure head can be adjusted to match the size of the deformation part, thus achieving precise control over the size of the force application point and the amount of correction, and improving the versatility of the forming device.

[0027] 3. By using multiple vertical support frames and height-fixed rings to synchronously adjust multiple cast iron pressure heads, it is possible to synchronously correct all deformed parts of the casting, thereby improving the correction efficiency. In addition, a cast iron pressure head is set at the same deformation part in the inner and outer cavities of the casting to perform positive and negative force correction, avoiding twisting and deformation near the area to be corrected.

[0028] 4. The deformation correction range is 0.1-8mm, and the single correction accuracy can reach 0.1mm / 40mm. The overall casting deformation correction qualification rate is increased by 5 times, from 26-30 hours / piece to 4-6 hours / piece, which significantly improves the correction accuracy and efficiency.

[0029] 5. Irregular thin-walled castings are placed in high-rigidity cast iron top-pressure straightening fixtures, which ensures good overall stability and overcomes the problem of random deformation of other parts of the castings during manual mechanical straightening.

[0030] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0031] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0032] Figure 1 This is a schematic diagram of the top-pressure straightening device for thin-walled castings according to the present invention;

[0033] Figure 2 This is a schematic diagram of the structure of the thin-walled casting straightening device supported by the mounting frame in this invention for processing the casting;

[0034] Figure 3 for Figure 2 Enlarged schematic diagram of the structure at point A in the diagram;

[0035] Figure 4 This is a linear schematic diagram showing the relationship between the deformation of the driving component and temperature in this invention.

[0036] Figure 5 This is a schematic diagram of the structure of the two thin-walled casting top-pressure straightening devices in this invention when they are at the same deformation location in the inner and outer cavities of the casting;

[0037] Figure 6 This is a schematic diagram of the cooperation structure between the rear drive device and the support frame in this invention;

[0038] Figure 7 This is a schematic diagram of the cross-sectional structure of the casting in this invention;

[0039] Figure 8 This is a schematic diagram of the direction adjustment support structure in this invention.

[0040] Figure label:

[0041] 1-Driver component; 2-Transmission component; 3-Cast iron jacking head; 4-Support frame; 5-Flat load-bearing bearing; 6-Front end limit switch; 7-Positive and negative terminals of power supply assembly; 8-Rear end temperature measuring thermocouple; 9-Casting; 10-Mounting bracket; 1001-Vertical support rod; 1002-Height fixing ring; 1003 Casting support beam; 11-Direction adjustment support seat; 1101-Driving gear; 1102-Transmission gear; 1103-Driven gear; 12-Double column hydraulic arm; 13-Wheel worm gear. Detailed Implementation

[0042] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0043] A certain casting used in aerospace products has a thin-walled cavity. Before assembly and application, the casting needs to be calibrated to meet the usage requirements.

[0044] Because the casting has thin walls, large volume, and irregular surface, it is not easy to clamp and fix the casting. The top press has a complex and heavy structure, which is inconvenient to install. Furthermore, for thin-walled parts, the existing top press may affect the surface near the deformed part during the calibration process, causing the surface accuracy of the casting to fail to meet the requirements.

[0045] It is evident that traditional mechanical calibration methods lack strength, calibration capacity, and versatility. For calibration requirements from the inside out, current technology struggles to operate and control deformation during calibration. Therefore, top-pressing machines are generally not used for calibration; instead, manual hammering is employed.

[0046] However, the manual hammering method cannot accurately control the size of the force point and the amount of correction. Furthermore, for the deep cavities of the casting, such as the top of the casting cavity, manual hammering is laborious, time-consuming, and inefficient.

[0047] To address the aforementioned problems, this invention provides a top-pressure straightening fixture for thin-walled castings with irregular cross-sections, comprising a top-pressure straightening device, a rear-end drive device, and a high-frequency vibration device for eliminating stress in local straightening areas of the casting.

[0048] The top-pressure calibration device includes a driving component 1, a transmission component 2, a cast iron top-pressure head 3, a support frame 4, a heat source, and a mounting bracket 10, such as... Figure 1 As shown, the heat source, drive component 1, transmission component 2, and cast iron pressure head 3 are integrated and mounted on the support frame 4;

[0049] The rear drive unit is connected to the support frame 4 and the mounting frame 10 respectively, and is used to adjust the position of the support frame on the mounting frame 10;

[0050] During the calibration process, the casting to be calibrated is fixed on the mounting frame 10. The heat source controls the drive component 1 to deform and extrude the transmission component 2, which in turn drives the cast iron top pressure head 3 to extrude and calibrate the surface of the casting.

[0051] The shape of the driving component 1 varies at different temperatures. When heated, the driving component 1 is in an expanded state to compress the transmission component 2, which in turn drives the cast iron top pressure head 3 to move, ultimately achieving the shaping of the casting.

[0052] Furthermore, the driving component 1 is a conductor, and the heat source includes a power supply component that transmits current into the driving component 1. In this way, current flows inside the driving component 1, electrical energy is converted into internal energy, and the internal temperature of the driving component 1 is changed, thereby changing the shape of the driving component 1.

[0053] In one possible implementation, the driving component 1 is made of Ni / Ti bidirectional memory alloy. When current is applied, electrical energy is converted into internal energy, the temperature rises, and the Ni / Ti bidirectional memory alloy undergoes a martensitic transformation, causing the driving component 1 to deform. When the temperature drops, the driving component 1 can return to its original shape.

[0054] Compared with the prior art, the present invention adjusts the position of the support frame 4 through the rear drive device, which can conveniently adjust the cast iron top pressure head 3 to the surface of the casting to be shaped. Then, the heat source controls the drive component 1 to change its shape to squeeze the transmission component 2. The transmission component 1 drives the cast iron top pressure head 3 to move, thereby realizing the shaping of the casting. The structure is simple and does not require a complex mechanical force transmission mechanism, making the top pressure shaping device small and lightweight. In use, by controlling the temperature of the drive component 1 and the deformation state of the drive component 1, the amount of shaping in a single operation can be controlled. For deep cavities of the casting, it is easy to accurately control the size of the force point and the amount of shaping, making it convenient to use.

[0055] Specifically, the drive component 1 is spiral in shape. When current is applied, the Ni / Ti bidirectional memory alloy undergoes a martensitic transformation, and the spiral straightens to provide ejection force. After the temperature decreases, it returns to the spiral shape. Thus, in the direction of movement of the cast iron top pressure head 3, the spiral structure of the drive component can provide a large deformation to adapt to different deformations of the casting surface.

[0056] The two ends of the driving component 1 are connected to the positive and negative terminals 7 of the power supply component, respectively. Based on the thermal effect of the current, the temperature of the driving component will increase during the power-on time. At this time, as the temperature increases, the spiral deformation will continue to elongate. The deformation will stop when the temperature is maintained. When the power is turned off, the spiral Ni / Ti bidirectional memory alloy will cool and spring back to shrink.

[0057] Furthermore, a rear-end temperature measuring thermocouple 8 is also provided on the support frame 4 for measuring the temperature of the drive component 1. For example, the rear-end temperature measuring thermocouple 8 is a point contact thermocouple, so as to set the heating temperature of the spiral Ni / Ti bidirectional memory alloy according to the deformation data of the top pressure part of the casting, and control the amount of correction.

[0058] Furthermore, a front limit switch 6 is provided on the cast iron pressing head 3. The front limit switch 6 is a signal triggering device. When the cast iron pressing head 3 contacts the casting mold surface, the front limit switch 6 is triggered to determine the position of the cast iron pressing head 3.

[0059] Specifically, one end of the transmission component 2 is connected to the cast iron top pressure head 3, and the other end is connected to one end of the driving component 1, so as to transmit the ejection force generated by the deformation of the driving component 1 to the cast iron top pressure head 3, so that the cast iron top pressure head 3 moves relative to the support frame 4.

[0060] The other end of the drive component 1 is fixedly mounted on the support frame 4 so that when the drive component 1 deforms, the deformation generates an outward force that is transmitted toward the transmission component 3.

[0061] Specifically, such as Figure 6 As shown, the rear drive unit includes a direction adjustment support 11, a double-column hydraulic arm 12, and a worm gear 13.

[0062] One end of the direction adjustment support 11 is connected to the mounting frame 10, and the other end is fixedly connected to the double-column hydraulic arm 12. The direction adjustment support 11 can be a mechanical arm or a gear transmission structure, which can adjust the tilt direction of the double-column hydraulic arm 12.

[0063] For example, the direction adjustment support 11 may include a drive gear 1101, a transmission gear 1102, and a driven gear 1103; wherein, the drive gear 1101 meshes with the two transmission gears 1102, and the two transmission gears 1102 mesh with the driven gear 1103; the drive gear 1101 drives the driven gear 1103 to rotate through the two transmission gears 1102, so as to adjust the tilt direction of the double-column hydraulic arm 12.

[0064] One end of the double-column hydraulic arm 12 is fixedly connected to the middle of the tooth surface of the driven gear 1103, and the other end is fixedly connected to the worm gear 13. The double-column hydraulic arm 12 is a primary transmission device, which includes two hydraulic arms that can extend and retract synchronously, thereby adjusting the position of the worm gear 13 in the extension and retraction direction of the hydraulic arm.

[0065] One end of the worm gear 13 is fixedly connected to the double-column hydraulic arm 12, and the other end is connected to the support frame 4. The worm gear 13 is a two-stage transmission device. When in operation, the extension and retraction of the worm gear 13 causes the cast iron top pressure head 3 at the front end of the support frame 4 to move slightly toward the surface of the casting until the front limit switch 6 at the cast iron top pressure head 3 is triggered, and the worm gear 13 stops moving.

[0066] The extension and retraction direction of the worm gear 13 is consistent with the extension and retraction direction of the double-column hydraulic arm 12.

[0067] Specifically, the mounting frame 10 includes a vertical support rod 1001, a height-fixing ring 1002, and a cast support beam 1003.

[0068] The direction adjustment support 11 is mounted on the height fixing ring 1002, and the height fixing ring 1002 is mounted on the vertical support rod 1001.

[0069] The height of the height-fixing ring 1002 on the vertical support rod 1001 is adjustable. Alternatively, the height-fixing ring 1002 can be rotated and fixed on the vertical support rod 1001. Thus, by adjusting the position of the height-fixing ring 1002 on the vertical support rod 1001, the position of the direction adjustment support seat 11 can be adjusted, thereby adjusting the position of the cast iron top pressure head 3.

[0070] The height-fixed ring 1002 can slide on the vertical support rod 1001 and is fixedly connected to the vertical support rod 1001 by fastening bolts.

[0071] The vertical support rods 1001 are provided in multiple ways. For example, there are 5 vertical support rods 1001, 4 of which are distributed on the outside of the casting and 1 is distributed in the inner cavity of the casting. Multiple height-fixed rings 1002 can be installed to realize synchronous correction of all deformed parts.

[0072] The casting support beam 1003 is provided in at least two parts, which are distributed vertically. During the calibration, the casting is located between the two casting support beams 1003, and the upper and lower ends of the casting are fixed by the two casting support beams 1003.

[0073] The vertical support rod 1001 is connected to the casting support beam 1003 at both ends, and the vertical support rod 1001 and the casting support beam 1003 can be fastened together by connecting bolts.

[0074] Among them, the high-frequency vibration device can be a vibration stress relief device. For example, Huayun Haoke Energy-Vibration Stress Relief Device can be used, with its working end in contact with the outer surface of the casting correction part to perform high-frequency vibration treatment on the casting correction part.

[0075] In addition, the present invention also provides a method for top-pressing and straightening of thin-walled castings with irregular cross sections, which includes using the above-mentioned top-pressing and straightening fixture for thin-walled castings with irregular cross sections to straighten the castings.

[0076] Specifically, including:

[0077] Step 1: Adjust the quantity and installation position of the vertical support frame 1001 and the height fixing ring 1002;

[0078] Step 2: Use the casting support beam 1003 to fix and clamp the upper and lower ends of the casting;

[0079] Step 3: Based on the deformation data of the casting top pressure correction area, adjust the position of the cast iron top pressure head 3;

[0080] Step 4: Set the heating temperature of drive component 1 based on the deformation data of the top pressing part of the casting;

[0081] Step 5: Power is supplied to the drive component 1 through the power supply assembly. The drive component 1 deforms and drives the cast iron top pressure head 3 to act on the surface of the casting to be shaped. The temperature of the drive component 1 is detected by the rear-end temperature measuring thermocouple 8.

[0082] Step 6: After the temperature of the drive component 1 reaches the set heating temperature, maintain the temperature for a certain period of time, and then disconnect the current;

[0083] Step 7: Use a high-frequency vibration device to relieve stress on the parts of the casting that are being shaped.

[0084] Step 8: Re-inspect the calibrated casting until the deformation of the casting meets the contour requirements.

[0085] In step 1, based on the location distribution of the top-pressure correction parts of the casting and the casting size data, the number and installation position of the vertical support frame 1001 and the height-fixing ring 1002 are adjusted to achieve synchronous correction of all deformed parts.

[0086] In step 3, after the direction adjustment support 11 is installed on the height fixing ring 1002, the position of the cast iron top pressure head 3 is adjusted by the rear drive device based on the deformation data of the casting top pressure correction part, so as to set a cast iron top pressure head 3 at the same deformation part of the inner and outer cavities of the casting to perform positive and negative force correction.

[0087] In step 4, the method for obtaining deformation data of the casting under pressure is as follows: the model of the casting to be tested obtained by three-dimensional scanning is aligned with the theoretical casting model for assembly and measurement to obtain the absolute deformation of different parts of the casting.

[0088] Furthermore, based on the relationship between the deformation and temperature of drive 1, the linear regression equation corresponding to the deformation and temperature of drive 1 is obtained, as shown in equation (1) below.

[0089] y=0.8027*x-37.156 Formula (1)

[0090] Where y is the dependent variable, corresponding to the deformation L of driving component 1, and x is the independent variable, corresponding to the temperature T of driving component 1. The linear relationship between L and T is shown in the appendix. Figure 4 .

[0091] Among them, based on the relationship data of deformation and temperature of driving component 1 in Table 1 below, the above formula (1) is obtained. The relationship data is shown in Table 1 below.

[0092] Table 1 Relationship between Deformation of Driving Components and Temperature

[0093] Temperature (°C) 47.5 48 48.5 49 49.5 50 50.5 51 51.5 Elongation (mm) 1 1.6 2 2.4 2.6 2.9 3.2 3.4 3.9 Temperature (°C) 52 52.5 53 53.5 54 54.5 55 55.5 56 Elongation (mm) 4.5 5 5.3 5.7 6.2 6.4 7.1 7.6 8.1

[0094] In this case, the feed amount M of the cast iron pressing head 3 is the same as the deformation amount L of the driving component 1, and M satisfies:

[0095] M = ε + s (Equation 2)

[0096] Where ε is the absolute deformation at the point where the casting needs to be corrected, that is, the deformation value when the casting surface is concave or convex.

[0097] Where s is the maximum over-variable value of a single deformation, in order to overcome the influence of springback in the surface structure of the casting.

[0098] Among them, based on the absolute deformation ε at the point to be corrected in the casting and the main wall thickness t of the deformation part of the casting, the maximum over-variable value s of a single deformation is determined, as detailed in Table 2 below.

[0099] Table 2 shows the relationship between s, ε, and t.

[0100]

[0101] Therefore, after obtaining the absolute deformation of the part of the casting to be calibrated and the main wall thickness of the deformed part of the casting, the maximum over-variable value of a single deformation is obtained based on Table 2, and the feed amount of the cast iron top pressure head 3 is obtained based on Equation (2), that is, the deformation of the driving component 1 is obtained; finally, the temperature value corresponding to the driving component 1 is obtained based on Equation (1), thereby realizing the precise top pressure calibration of the part of the casting to be calibrated by controlling the temperature of the driving component 1.

[0102] The size and location of the force application point are determined based on the effective area of ​​the casting to be calibrated. Based on this, the size of the cast iron top pressure head 3 is designed.

[0103] In step 5, when the deformed part of the casting protrudes outward, the cast iron top pressure head 3 on the outside of the casting is activated to correct the bulging deformed part of the casting. The cast iron top pressure head 3 located inside the casting assists in pressing at the position to be corrected, so as to avoid twisting and deformation near the area to be corrected of the casting.

[0104] When the deformed part of the casting becomes concave, the cast iron top pressure head 3 inside the casting is activated to correct the concave deformation part of the casting. The cast iron top pressure head 3 located outside the casting assists in pressing at the position to be corrected, avoiding large-area deformation near the area to be corrected.

[0105] The position of the cast iron top pressure head 3 is adjusted by using the double-column hydraulic arm 12 so that the cast iron top pressure head 3, which is used to assist in pressing at the position to be calibrated, is always pressed at the position to be calibrated.

[0106] In step 6, the heat preservation process is as follows: after the temperature of the driving component 1 reaches the set heating temperature, the heat preservation lasts for 5-10 seconds. During this process, the cast iron top pressure head 3, which is used to assist in pressing at the position to be shaped, is in a fixed state relative to the casting.

[0107] Compared with the prior art, the present invention adjusts the position of the support frame 4 through the rear drive device, which can conveniently adjust the cast iron top pressure head 3 to the surface of the casting to be shaped. Then, the heat source controls the drive component 1 to change its shape to squeeze the transmission component 2. The transmission component 2 drives the cast iron top pressure head 3 to move, thereby realizing the shaping of the casting. The structure is simple and does not require a complex mechanical force transmission mechanism, making the top pressure shaping device small and lightweight.

[0108] By controlling the temperature parameters of the driving component and the amount of deformation of the driving component, it is possible to control the amount of single-time correction, adapt to different deformation parts, and adjust the size of the cast iron top pressure head to match the size of the deformation part. This achieves precise control over the size of the force application point and the amount of correction, thus improving the versatility of the forming device.

[0109] The deformation correction range is 0.1-8mm, and the single correction accuracy can reach 0.1mm / 40mm. The overall casting deformation correction qualification rate is increased by 5 times, from 26-30 hours / piece to 4-6 hours / piece, which significantly improves the correction accuracy and efficiency.

[0110] By using multiple vertical support frames 1001 and height-fixed rings 1002, multiple cast iron pressure heads 3 can be adjusted synchronously, enabling synchronous correction of all deformed parts of the casting, thus improving correction efficiency. In addition, a cast iron pressure head 3 is set at the same deformation part in the inner and outer cavities of the casting to perform positive and negative force correction, avoiding twisting and deformation near the area to be corrected of the casting.

[0111] The irregular thin-walled casting is placed in a high-rigidity cast iron top-pressure straightening fixture, which has good overall stability and overcomes the problem of random deformation of other parts of the casting during manual mechanical straightening.

[0112] Example 1

[0113] A top-pressure straightening fixture for thin-walled castings with irregular cross-sections includes a top-pressure straightening device, a rear-end drive device, and a high-frequency vibration device for eliminating stress in local straightening areas of the casting.

[0114] The top-pressure calibration device includes a driving component 1, a transmission component 2, a cast iron top-pressure head 3, a support frame 4, a heat source, and a mounting frame 10.

[0115] Specifically, the driving component 1 is a spiral-shaped Ni / Ti bidirectional shape memory alloy, with one end fixedly connected to the support frame 4 and the other end connected to the transmission component 2.

[0116] When current is applied to the drive component 1, the Ni / Ti bidirectional shape memory alloy undergoes a martensitic transformation, and the spiral shape straightens, squeezing the transmission component 2 to provide an ejector force; after the temperature decreases, it returns to the spiral shape to eliminate the ejector force.

[0117] When energized, the current flowing into the driving component 1 does work based on the current heating effect, converting electrical energy into internal energy. This causes the resistor inside the driving component 1 to heat up. As the resistor inside the driving component 1 heats up, its resistance increases. According to q = u 2 As the resistance heats up, the temperature rises faster and faster, eventually causing the Ni / Ti bidirectional shape memory alloy to undergo a martensitic transformation.

[0118] The magnitude of the ejection force generated by the driving component 1 is determined by the Ni / Ti bidirectional shape memory alloy. For example, the deformation force of this alloy is 200-350 MPa.

[0119] The shaping speed of the cast iron top pressure head 3 is determined by the two-way deformation of the Ni / Ti bidirectional memory alloy. The speed of the Ni / Ti bidirectional memory alloy in the two shape transformations is matched with the shaping speed of the casting, which is much smaller than the shaping deformation speed allowed for the casting.

[0120] The amount of deformation of the driving component 1 is controlled by temperature, and the specific correspondence is shown in Table 1 above.

[0121] After obtaining the deformation amount of the part of the casting to be calibrated and the main wall thickness of the deformed part of the casting, the maximum over-variable value of a single deformation is obtained based on Table 2, and the feed amount of the cast iron top pressure head 3 is obtained based on Equation (2), that is, the deformation of the driving part 1 is obtained; finally, the temperature value corresponding to the driving part 1 is obtained based on Equation (1), so as to realize the precise top pressure calibration of the part of the casting to be calibrated by controlling the temperature of the driving part 1.

[0122] The material at the connection between the support frame 4 and the drive component 1 is a heat-insulating high-strength material. For example, the material is boron nitride high-temperature ceramic. This prevents the current flowing into the drive component 1 from being transmitted to the support frame 4, and also prevents the part from undergoing elastic deformation during the deformation of the drive component 1, which could lead to pressing failure or reduced pressing efficiency, thus improving the calibration accuracy.

[0123] Specifically, one end of the transmission component 2 is connected to the driving component 1, and the other end is connected to the cast iron pressing head 3, so as to transmit the pressing pressure of the driving component 1 to the cast iron pressing head 3, thereby driving the cast iron pressing head 3 to move, so as to correct the shape of the casting.

[0124] The transmission component 2 is made of a heat-insulating high-strength material, for example, boron nitride high-temperature ceramic. This prevents the current flowing into the drive component 1 from being transmitted to the cast iron pressing head 3, and also prevents the part from undergoing elastic deformation during the deformation of the drive component 1, which could lead to pressing failure or reduced pressing efficiency, thus improving the calibration accuracy.

[0125] Among them, a flat load-bearing bearing 5 is provided on the support frame 4, and the transmission component 2 is slidably inserted into the flat load-bearing bearing 5 to ensure the stability of the movement of the transmission component 2, thereby improving the stability of the cast iron top pressure head 3 being ejected.

[0126] Specifically, one end face of the cast iron pressing head 3 is connected to the transmission component 2, and its other end face is the pressing surface, such as... Figure 3 As shown, during the calibration process, the top pressure surface abuts against the surface of the casting 9 to be calibrated.

[0127] The cast iron pressing head 3 is detachably connected to the transmission component 2 so that the size of the cast iron pressing head 3 can be adjusted to fit the part of the casting to be shaped.

[0128] The moving direction of the transmission component 2 is perpendicular to the pressing surface of the cast iron pressing head 3.

[0129] The size and location of the force application point are determined based on the effective area of ​​the casting to be calibrated. Based on this, the size of the clamping surface of the cast iron top pressure head 3 is designed.

[0130] Specifically, a front limit switch 6 is provided on the pressing surface of the cast iron top pressure head 3. During the calibration, the mold surface of the casting presses against the front limit switch 6, causing it to extend and retract inside the cast iron top pressure head 3. At this time, the front limit switch 6 is in the triggered state, indicating that the fixed pressure surface of the cast iron top pressure head 3 is in a close fit with the mold surface of the casting.

[0131] The cast iron pressing head 3 is equipped with a signal generating device. When the front limit switch 6 is fully extended into the cast iron pressing head 3, the signal generating device is triggered to determine that the pressing surface of the cast iron pressing head 3 is in contact with the surface to be corrected of the casting. Then, the power supply component can be turned on to supply current to the drive component 1 to control the deformation of the drive component 1.

[0132] Specifically, the heat source includes a power supply component, the positive and negative terminals 7 of which are connected to the two ends of the drive component 1 respectively, in order to transmit current to the drive component 1.

[0133] When powered on, the current flows from the positive terminal of the power supply component to one end of the drive component 1, and then flows back to the negative terminal of the power supply component through the other end of the drive component 1.

[0134] The positive or negative terminal of the power supply component is connected to the drive component 1 through the support frame 4, and the negative or positive terminal of the power supply component is connected to the other end of the drive component 1 through the support frame 4 and the transmission component 2, and moves synchronously with the transmission component 2.

[0135] Specifically, the power supply component outputs low-voltage DC power, which is safe and reliable. For example, the voltage is 24V and the power is 1000-1500W.

[0136] Among them, a rear-end temperature measuring thermocouple 8 is provided on the support frame 4. One end of the rear-end temperature measuring thermocouple 8 passes through the transmission member 2 and is connected to the end of the driving member 1, while the other end is located outside the support frame 4. When the transmission member 2 moves, it moves synchronously with the transmission member 2.

[0137] When powered on, the temperature of the driving component 1 is measured by the thermocouple 8 at the back end, and the control circuit is fed back to control the current transmission.

[0138] Specifically, the support frame 4 is a cavity structure, the driving component 1 is set inside the cavity, the cast iron top pressure head 3 is located outside the cavity, and the wall of the support frame 4 has a heat insulation layer to reduce the temperature inside the cavity and the heat exchange efficiency outside the cavity, thereby preventing heat loss when the driving component 1 heats up, improving the heating efficiency, and thus controlling the deformation rate of the driving component 1.

[0139] The wall material of the support frame 4 is as follows, from the inside out: 1mm thick 304 stainless steel, 2-3mm thick high-silica limiting cloth (silica content greater than 95%), 2-3mm thick aluminum silicate fiber felt, and 3-4mm thick 304 stainless steel plate.

[0140] In this way, the strength of the support frame is increased by the inner and outer layers of stainless steel plates, and the heat exchange efficiency between the inner and outer walls of the support frame is reduced by the high silica oxygen limiting cloth and aluminum silicate limiting felt between the two layers of stainless steel plates, thus providing thermal insulation function.

[0141] An opening is provided on one end face of the support frame 4, allowing the negative or positive pole of the rear-end temperature measuring thermocouple 8 and the power supply assembly to move within the opening.

[0142] One end of the support frame 4 is the mounting end for the cast iron top pressure head 3, and the other end of the support frame 4 is the fixed end. The fixed end is connected to the rear drive device for adjusting the position of the support frame so as to adjust the position of the top pressure alignment device.

[0143] Specifically, the rear drive unit includes: a direction adjustment support 11, a double-column hydraulic arm 12, and a worm gear 13.

[0144] Among them, such as Figure 6 As shown, one end of the directional adjustment support 11 is connected to the mounting bracket 10, and the other end is fixedly connected to the double-column hydraulic arm 12. The directional adjustment support 11 includes a drive gear 1101, a transmission gear 1102, and a driven gear 1103.

[0145] Among them, such as Figure 8 As shown, the driving gear 1101 meshes with two transmission gears 1102, and the two transmission gears 1102 mesh with the driven gear 1103; the driving gear 1101 drives the driven gear 1103 to rotate through the two transmission gears 1102, so as to adjust the tilt direction of the double-column hydraulic arm 12.

[0146] One end of the double-column hydraulic arm 12 is fixedly connected to the middle of the tooth surface of the driven gear 1103, and the other end is fixedly connected to the worm gear 13. The double-column hydraulic arm 12 is a primary transmission device, which includes two hydraulic arms that can extend and retract synchronously, thereby adjusting the position of the worm gear 13 in the extension and retraction direction of the hydraulic arm.

[0147] A braking structure, such as a handbrake-like structure, can be provided at the drive gear 1101. When it is necessary to fix the driven gear 1103, the drive gear 1101 is fixed by the braking structure to prevent the driven gear 1103 from rotating.

[0148] The device may include a frame for fixing the shafts at the ends of the drive gear 1101, transmission gear 1102, and driven gear 1103. The frame avoids the position where the connection between the double-column hydraulic arm 12 and the driven gear 1103 rotates 180° up and down.

[0149] One end of the worm gear 13 is fixedly connected to the double-column hydraulic arm 12, and the other end is connected to the support frame 4. The worm gear 13 is a two-stage transmission device. When in operation, the extension and retraction of the worm gear 13 causes the cast iron top pressure head 3 at the front end of the support frame 4 to move slightly toward the surface of the casting until the front limit switch 6 at the cast iron top pressure head 3 is triggered, and the worm gear 13 stops moving.

[0150] The extension and retraction direction of the worm gear 13 is consistent with the extension and retraction direction of the double-column hydraulic arm 12.

[0151] Specifically, the mounting frame 10 includes a vertical support rod 1001, a height-fixing ring 1002, and a cast support beam 1003.

[0152] The directional adjustment support 11 is mounted on the height fixing ring 1002, which is mounted on the vertical support rod 1001. The position of the directional adjustment support 11 is adjusted by adjusting the position of the height fixing ring 1002 on the vertical support rod 1001, thereby adjusting the position of the cast iron top pressure head 3.

[0153] Multiple height-fixing rings 1002 are provided, which can slide on the vertical support rod 1001. The height-fixing rings 1002 are fixedly connected to the vertical support rod 1001 by fastening bolts.

[0154] The height-fixing ring 1002 can rotate around the vertical support rod 1001, and the height-fixing ring 1002 is fixedly connected to the vertical support rod 1001 by fastening bolts.

[0155] Among them, there are at least 5 vertical support rods 1001. When the casting is calibrated, 4 vertical support rods 1001 are distributed on the outside of the casting and 1 vertical support rod 1001 is distributed in the inner cavity of the casting. Based on the distribution of the parts of the casting to be calibrated, multi-height fixing rings 1002 are set on the vertical support rods 1001 to realize the simultaneous calibration of multiple parts of the casting to be calibrated. In addition, when calibrating the casting, the casting is clamped, fixed and calibrated by cast iron pressure heads 3 set inside and outside the casting.

[0156] The casting support beam 1003 is provided in at least two parts, which are distributed vertically. During the calibration, the casting is located between the two casting support beams 1003, and the upper and lower ends of the casting are fixed by the two casting support beams 1003.

[0157] The vertical support rod 1001 is connected to the casting support beam 1003 at both ends, and the vertical support rod 1001 and the casting support beam 1003 can be fastened together by connecting bolts.

[0158] Among them, the casting support beam 1003 has a "+" shaped structure, and the vertical support rod 1001 can adjust and fix the position of the casting support beam 1003 located at the upper end.

[0159] Specifically, the high-frequency vibration device is Huayunhaoke Energy-Vibration Stress Relief Equipment, whose working end contacts the outer surface of the casting straightening part, and is used to perform high-frequency vibration treatment on the casting straightening part.

[0160] The high-frequency vibration device is detachably mounted on the mounting bracket 10.

[0161] Example 2

[0162] A method for top-pressure correction of thin-walled castings with irregular cross-sections includes:

[0163] Step 1: Obtain deformation data of the top-pressure area of ​​the casting;

[0164] Specifically, including:

[0165] S101: Obtain the absolute deformation ε of different parts of the casting to be calibrated;

[0166] Specifically, the casting 9 is scanned to obtain a three-dimensional model of the casting; and based on the machining datum of the drawing, the theoretical model of the casting and the three-dimensional model obtained by scanning are aligned and measured to obtain the absolute deformation ε of different parts of the casting to be calibrated.

[0167] In this process, the castings that have been quenched and are not yet ready for aging are placed on a platform, and a 3D scanner is used to scan the inner and outer contours of the castings to obtain a 3D model of the castings.

[0168] The part to be corrected is the deformed part of the casting.

[0169] S102: Obtain the main wall thickness t of different parts of the casting to be calibrated;

[0170] Specifically, a wall thickness gauge is used to measure the thickness of the part of the casting to be calibrated, and the wall thickness value t at that location is obtained.

[0171] Step 2: Based on the deformation data of the casting parts to be calibrated, set the heating temperature of the drive component 1 at different parts to be calibrated;

[0172] Specifically, including:

[0173] S201: Based on the absolute deformation ε of the part of the casting to be calibrated and the main wall thickness t of the part to be calibrated, determine the maximum single deformation value s of the part to be calibrated.

[0174] Among them, based on ε and t, the maximum variable value s of a single deformation is determined, and the correspondence between s, ε and t is detailed in Table 2 above.

[0175] S202: Based on ε and s, obtain the feed amount M of the cast iron top pressure head 3, and then determine the deformation amount L of the driving component 1;

[0176] In this case, the feed amount M of the cast iron pressing head 3 is the same as the deformation amount L of the driving component 1, and M satisfies:

[0177] M = ε + s (Equation 2)

[0178] Where ε is the absolute deformation at the part of the casting to be corrected, that is, the deformation value when the casting surface is concave or convex.

[0179] Where s is the maximum over-variable value of a single deformation, in order to overcome the influence of springback in the surface structure of the casting.

[0180] S203: Based on L, obtain the heating temperature T of the driving component 1.

[0181] Based on the relationship between the deformation and temperature of drive 1, the linear regression equation corresponding to the deformation and temperature of drive 1 is obtained, as shown in equation (1).

[0182] y=0.8027*x-37.156 Formula (1)

[0183] Where y is the dependent variable, corresponding to the deformation L of driving component 1, and x is the independent variable, corresponding to the temperature T of driving component 1. The linear relationship between L and T is shown in the appendix. Figure 4 .

[0184] Among them, based on the relationship data between the deformation amount and temperature of the driving component 1 in Table 1 above, the above formula (1) is obtained. The relationship data is shown in Table 1 above.

[0185] Step 3: Based on the determined location of the part to be calibrated, clamp it using the top-pressure calibrating tooling casting;

[0186] Specifically, including:

[0187] S301: Determine the quantity and installation position of the vertical support frame 1001 and the height fixing ring 1002;

[0188] Specifically, based on the location of the part to be calibrated and the casting size data, the number and installation position of the vertical support frame 1001 and the height-fixing ring 1002 are adjusted to achieve synchronous calibration of all deformed parts.

[0189] S302: The upper and lower ends of the casting are fixed and clamped using the casting support beam 1003;

[0190] One method is to use two casting support beams 1003 to press the casting together and fix it in place.

[0191] S303: Based on the determined location of the part to be calibrated, adjust the position of the cast iron top pressure head 3;

[0192] Specifically, after adjusting the height fixing ring 1102 to the corresponding position, the direction adjustment support 11 is installed on the height fixing ring 1002, and then the position of the cast iron top pressure head 3 is adjusted by the rear drive device so that a cast iron top pressure head 3 is set at the same deformation part of the inner and outer cavities of the casting to perform positive and negative force correction.

[0193] The method for adjusting the position of the cast iron jacking head 3 using the rear-end drive device is as follows:

[0194] S3031: Adjust the tail direction adjustment support 11 so that the pressing surface of the cast iron pressing head 3 is parallel to the surface of the part of the casting to be shaped.

[0195] S3032: Start the double-column hydraulic arm 12 to move the clamping surface of the cast iron top pressure head 3 to the mold surface of the part of the casting to be shaped;

[0196] The telescopic movement direction of the double-column hydraulic arm 12 is perpendicular to the pressing surface of the cast iron top pressure head 3.

[0197] When the front limit switch on the cast iron top pressure head 3 contacts the surface of the casting to be shaped, the double-column hydraulic arm stops extending forward.

[0198] S3033: Start the worm gear 13, and slightly move the top pressure surface of the cast iron top pressure head 3 to the part of the casting to be shaped until the front limit switch 6 on the cast iron top pressure head 3 is triggered, and the worm gear 13 stops moving.

[0199] Step 4: Based on the heating temperature of the drive component 1 at different locations to be calibrated and the processing method of the locations to be calibrated, the locations to be calibrated in the casting are calibrated.

[0200] Specifically, including:

[0201] S401: Power is supplied to the drive unit 1 through the power supply assembly. The drive unit 1 deforms and drives the cast iron top pressure head 3 to act on the surface of the casting to be shaped. The temperature of the drive unit 1 is detected by the rear temperature measuring thermocouple 8.

[0202] Specifically, when the part to be calibrated protrudes outward, the cast iron pressure head 3 on the outside of the casting is activated to correct the protruding part to be calibrated. The cast iron pressure head 3 located inside the casting assists in pressing the part to be calibrated to prevent the area near the part to be calibrated from twisting and deforming.

[0203] When the part to be calibrated is concave, the cast iron top pressure head 3 inside the casting is activated to correct the concave part to be calibrated. The cast iron top pressure head 3 located outside the casting assists in pressing on the part to be calibrated to avoid twisting and deformation in the vicinity of the part to be calibrated.

[0204] The position of the cast iron top pressure head 3 is adjusted by using the double-column hydraulic arm 12 so that the cast iron top pressure head 3, which is used to assist in pressing at the position to be calibrated, is always pressing at the position to be calibrated.

[0205] When the driving component 1 is directly heated by current according to the set deformation requirement, the driving component 1 deforms due to heat, the spiral shape straightens, and the transmission component 3 moves forward, driving the cast iron top pressure head 4 to move, and then the contact part between the casting and the cast iron top pressure head 4 deforms.

[0206] S402: After the temperature of the drive component 1 reaches the set heating temperature, it is kept at that temperature for a certain period of time, and then the current is disconnected.

[0207] Specifically, after the temperature of the driving component 1 reaches the set heating temperature, it is kept warm for 5-10 seconds. During this period, the temperature of the driving component is continuously detected by the back-end temperature measuring thermocouple 8. If the temperature of the driving component 1 reaches the preset value, the circuit is disconnected and the power supply is stopped. If the temperature of the driving component 1 is lower than the preset value, the circuit is connected. In this way, based on the temperature detection results, the repeated on and off of the power supply circuit is controlled to keep the driving component 1 warm.

[0208] During the heat preservation period, the cast iron top pressure head 3, which is used to assist in pressing the part to be shaped, is in a fixed state relative to the casting.

[0209] S403: Stress relief treatment is performed on the shaped parts of the casting.

[0210] Specifically, including:

[0211] S4031: Remove the top pressure calibration fixture and bring the working end of the high-frequency vibration device into contact with the outer surface of the calibrated part of the casting;

[0212] Among them, the high-frequency vibration device is Huayunhaoke Energy-Vibration Stress Relief Equipment.

[0213] S4032: Start the high-frequency vibration device;

[0214] Specifically, the vibration frequency is 400-500Hz and the vibration time is 20-35s, in order to eliminate the stress in the local shaping parts of the casting and prevent the parts from springing back.

[0215] S4033: After the high-frequency vibration device has completed its high-frequency vibration, the high-frequency vibration device shall be removed.

[0216] Specifically, after the high-frequency vibration ends, the working end of the high-frequency vibration device remains in contact with the outer surface of the shaped part of the casting for 40-60 seconds, and then the high-frequency vibration device is removed to further reduce the risk of springback in that part.

[0217] Step 5: Re-inspect the calibrated casting until the deformation of the casting meets the contour requirements.

[0218] Specifically, including:

[0219] S501: Scan the calibrated casting to obtain a preliminary 3D model of the calibrated casting;

[0220] S502: Align and measure the casting theoretical model and the acquired 3D model to obtain the absolute deformation of the deformed parts of the casting.

[0221] S503: If the deformation of the casting meets the profile requirements, the casting calibration shall be terminated.

[0222] S504: If the deformation of the casting does not meet the profile requirements, return to step 1 until the deformation of the casting meets the profile requirements.

[0223] This method eliminates the need to disassemble internal calibration fixtures; instead, castings are scanned directly to develop a secondary calibration plan.

[0224] Among them, the contour requirements are determined based on the processing technology requirements, and the absolute deformation is within the range of 0.5mm to meet the contour requirements.

[0225] Example 3

[0226] The difference from Example 2 is that the selection of the contact point between the top-pressure straightening fixture and the casting is different during the straightening process. This is to effectively prevent the casting 9 from shifting during the top-pressure straightening process and avoid the casting 9 from twisting, deforming or cracking through precise multi-point straightening clamping.

[0227] Specifically, including:

[0228] Step 1: Based on the absolute deformation of different deformation parts of the casting, determine multiple top-pressure correction parts;

[0229] Specifically, including:

[0230] S101: Obtain the absolute deformation of different deformation parts of casting 9;

[0231] Specifically, including:

[0232] S1011: Scan casting 9 to obtain the 3D model of the casting;

[0233] In this process, the castings that have been quenched and are not yet ready for aging are placed on a platform, and a 3D scanner is used to scan the inner and outer contours of the castings to obtain a 3D model of the castings.

[0234] S1012: Based on the drawing processing datum, the theoretical model of the casting and the three-dimensional model obtained by scanning are aligned and measured to obtain the absolute deformation of different deformation parts of the casting.

[0235] S102: Take the deformed part with the maximum deformation as the base point, and take the reinforcing rib that is closest to the base point as the origin;

[0236] S103: Based on the origin position, arrange the top pressure correction parts to obtain multiple top pressure correction parts.

[0237] Specifically, such as Figure 7 As shown, the top pressure correction points are arranged according to the principle that the distance between adjacent top pressure correction parts is no more than 1 / 8 of the cross-sectional perimeter and the distance between adjacent contour surfaces is no more than 200mm.

[0238] Among them, the distance between adjacent top-pressure correction parts should not be too large to avoid causing nearby deformation areas to recover, which would increase the possibility of correction cracks; nor should it be too small, as this would make the correction tooling layout troublesome and increase the difficulty of data control.

[0239] Among these, the distance between adjacent contour surfaces should not be too large, as this can easily cause distortion and deformation; nor should it be too small, as this would increase the workload of scanning and analyzing data after calibration.

[0240] Step 2: Install top-pressure alignment devices at all top-pressure alignment points to implement corresponding internal and external top-pressure fixing;

[0241] The position of the support frame 4 is adjusted by the rear drive device so that the pressing surface of the cast iron top pressure head 3 abuts against the profile surface at the top pressure and shaping part.

[0242] Specifically, including:

[0243] S201: Determine the quantity and installation position of the vertical support frame 1001 and the height fixing ring 1002;

[0244] In this process, based on the distribution of the top pressure correction parts and the casting size data, the number and installation position of the vertical support frame 1001 and the height fixing ring 1002 are adjusted to achieve synchronous correction of all deformed parts.

[0245] S202: The upper and lower ends of the casting are fixed and clamped using the casting support beam 1003;

[0246] One method is to use two casting support beams 1003 to press the casting together and fix it in place.

[0247] S203: Based on the determined position of the top pressure correction part, adjust the position of the cast iron top pressure head 3;

[0248] Specifically, after adjusting the height fixing ring 1102 to the corresponding position, the direction adjustment support 11 is installed on the height fixing ring 1002, and then the position of the cast iron top pressure head 3 is adjusted by the rear drive device so that a cast iron top pressure head 3 is set at the same deformation part of the inner and outer cavities of the casting to perform positive and negative force pressing and fixing.

[0249] The method for adjusting the position of the cast iron jacking head 3 using the rear-end drive device is as follows:

[0250] S2031: Adjust the tail direction adjustment support 11 so that the top pressure surface of the cast iron top pressure head 3 is parallel to the profile surface at the top pressure correction part;

[0251] The drive gear 1101 can be driven manually. When the drive gear 1101 is rotated clockwise, the transmission gear 1102 drives the driven gear 1103 to rotate clockwise. When the drive gear 1101 is rotated counterclockwise, the transmission gear 1102 drives the driven gear 1103 to rotate counterclockwise.

[0252] When the drive gear 1101 does not rotate, the driven gear 1103 remains fixed. This allows for the adjustment of the tilt direction of the double-column hydraulic arm 12, thereby adjusting the position of the top pressure surface of the cast iron top pressure head 3.

[0253] S2032: Start the double-column hydraulic arm 12 to move the pressing surface of the cast iron top pressure head 3 to the profile of the top pressure and shaping part;

[0254] The telescopic movement direction of the double-column hydraulic arm 12 is perpendicular to the pressing surface of the cast iron top pressure head 3.

[0255] When the front limit switch on the cast iron jacking head 3 contacts the profile at the jacking and straightening part, the double-column hydraulic arm stops extending forward.

[0256] S2033: Start the worm gear 13, and make the top pressure surface of the cast iron top pressure head 3 slightly move at the top pressure correction part until the front limit switch 6 on the cast iron top pressure head 3 is triggered, and the worm gear 13 stops moving.

[0257] Step 3: Obtain the absolute deformation of multiple top-pressure straightening parts and determine whether the absolute deformation of the top-pressure straightening parts meets the casting profile requirements;

[0258] Specifically, including:

[0259] S301: Mark the top pressure correction area on the three-dimensional model of the casting and obtain the absolute deformation of the top pressure correction area;

[0260] Specifically, on the three-dimensional view comparing the theoretical model of the casting and the three-dimensional model obtained by scanning, the corresponding top pressure correction points are marked, and the absolute deformation at the corresponding top pressure correction points is measured.

[0261] S302: Determine whether the deformation of the top-pressure correction part meets the requirements of the casting profile;

[0262] Among them, the contour requirements are determined based on the processing technology requirements, and the absolute deformation is greater than 0.5mm, which does not meet the contour requirements.

[0263] The profile requirements are determined based on the processing technology requirements, and the absolute deformation is within the range of 0.5mm to meet the profile requirements.

[0264] For the top-pressed correction parts that meet the contour requirements, the top-pressed correction device is used to implement corresponding top-pressing fixation inside and outside to prevent the parts from twisting and deforming.

[0265] Step 4: Using the top pressure correction points that do not meet the casting contour requirements as top pressure correction points, use the top pressure correction device to perform top pressure correction at the top pressure correction points.

[0266] Specifically, including:

[0267] S401: Based on the deformation data at the top pressure correction point, set the heating temperature of the drive component 1 of the top pressure correction device;

[0268] Specifically, including:

[0269] S4011: Based on the absolute deformation ε at the top pressure correction point and the main body wall thickness t at the top pressure correction point, determine the maximum single deformation value s at the top pressure correction point;

[0270] Among them, the thickness at the top pressure calibration point is detected by a wall thickness gauge to obtain the wall thickness value t at that point.

[0271] Among them, based on ε and t, the maximum overvariable value s of a single deformation is determined, and the correspondence between s, ε and t is shown in Table 2 above.

[0272] S4012: Based on ε and s, obtain the feed amount M of the cast iron top pressure head 3, and then determine the deformation amount L of the driving component 1;

[0273] In this case, the feed amount M of the cast iron pressing head 3 is the same as the deformation amount L of the driving component 1, and M satisfies:

[0274] M = ε + s (Equation 2)

[0275] Where ε is the absolute deformation at the top pressure correction point, that is, the deformation value when the casting surface is concave or convex.

[0276] Where s is the maximum over-variable value of a single deformation, in order to overcome the influence of springback in the surface structure of the casting.

[0277] S4013: Based on L, obtain the heating temperature T of drive component 1.

[0278] Among them, based on the correspondence between the deformation amount and temperature of drive 1, the linear regression equation corresponding to the deformation amount and temperature of drive 1 is obtained, as shown in equation (1) below.

[0279] y=0.8027*x-37.156 Formula (1)

[0280] Where y is the dependent variable, corresponding to the deformation L of driving component 1, and x is the independent variable, corresponding to the temperature T of driving component 1. The linear relationship between L and T is shown in the appendix. Figure 4 .

[0281] Among them, based on the relationship data between the deformation amount and temperature of the driving component 1 in Table 1 above, the above formula (1) is obtained. The relationship data is shown in Table 1 above.

[0282] Therefore, after obtaining the deformation amount and the main wall thickness at the top pressure calibration point, the maximum single deformation value at the top pressure calibration point is obtained based on Table 2. Then, the feed amount of the cast iron top pressure head 3 is obtained based on Equation (2), that is, the deformation of the driving component 1 is obtained. Finally, the temperature value corresponding to the driving component 1 is obtained based on Equation (1), thereby realizing the accurate top pressure calibration at the top pressure calibration point by controlling the temperature of the driving component 1.

[0283] S402: Power is supplied to the drive component 1 through the power supply component of the top pressure straightening device. The drive component 1 deforms and drives the cast iron top pressure head 3 to act on the surface of the casting to be straightened. The temperature of the drive component is detected by the temperature measuring thermocouple 8 at the rear end of the top pressure straightening device.

[0284] The internal drive component 1, located inside the casting, controls the internal heat source to provide the ejector force, or the external drive component 1, located outside the casting, controls the external heat source to provide the ejector force, in order to correct the shape of the casting.

[0285] Specifically, when the surface at the top pressure correction point bulges outward, the cast iron top pressure head 3 on the outside of the casting is activated to correct the bulging top pressure correction point. The cast iron top pressure head 3 located inside the casting assists in squeezing at the top pressure correction point to prevent twisting and deformation in the vicinity of the top pressure correction point area.

[0286] When the surface at the top pressure correction point is concave, the cast iron top pressure head 3 inside the casting is activated to correct the concave top pressure correction point. The cast iron top pressure head 3 located outside the casting assists in pressing at the top pressure correction point to avoid twisting and deformation in the vicinity of the top pressure correction point area.

[0287] The position of the cast iron top pressure head 3 is adjusted by using the double-column hydraulic arm 12 so that the cast iron top pressure head 3, which is used to assist in pressing at the top pressure calibration point, is always pressed at the top pressure calibration point.

[0288] When the driving component 1 is directly heated by current according to the set deformation requirement, the driving component 1 deforms due to heat, the spiral shape straightens, and the transmission component 3 moves forward, driving the cast iron top pressure head 4 to move, and then the contact part between the casting and the cast iron top pressure head 4 deforms.

[0289] S403: After the temperature of the drive component 1 reaches the set heating temperature, it is kept warm, and the current is disconnected after the heat preservation is completed.

[0290] Specifically, after the temperature of the driving component 1 reaches the set heating temperature, it is kept warm for 5-10 seconds. During this period, the temperature of the driving component is continuously detected by the back-end temperature measuring thermocouple 8. If the temperature of the driving component 1 reaches the preset value, the circuit is disconnected and the power supply is stopped. If the temperature of the driving component 1 is lower than the preset value, the circuit is connected. In this way, based on the temperature detection results, the repeated on and off of the power supply circuit is controlled to keep the driving component 1 warm.

[0291] During the heat preservation period, the cast iron top pressure head 3, which is used to assist in the extrusion at the top pressure correction point, is in a fixed state relative to the casting 9.

[0292] S404: High-frequency vibration treatment is applied to the top pressure calibration point to eliminate the stress at the top pressure calibration point;

[0293] Specifically, including:

[0294] S4041: Remove the top pressure calibration fixture and bring the working end of the high-frequency vibration device into contact with the outer surface at the top pressure calibration point;

[0295] Among them, the high-frequency vibration device is Huayunhaoke Energy-Vibration Stress Relief Equipment.

[0296] S4042: Start the high-frequency vibration device;

[0297] Specifically, the vibration frequency is 400-500Hz and the vibration time is 20-35s. In this way, after the top pressure calibration point is calibrated, the stress generated at the top pressure calibration point will be eliminated to prevent the rebound of this part.

[0298] S4043: After the high-frequency vibration device has completed its high-frequency vibration, the high-frequency vibration device shall be removed.

[0299] Specifically, after the high-frequency vibration ends, the front end of the high-frequency vibration device remains in contact with the outer surface of the top pressure calibration point for 40-60 seconds, and then the high-frequency vibration device is removed to further reduce the risk of rebound at this location.

[0300] S405: Re-inspect the calibrated casting 9 until the deformation of the casting meets the contour requirements.

[0301] Specifically, including:

[0302] S4051: Scan the calibrated casting to obtain a 3D model of the calibrated casting;

[0303] S4052: Align and measure the theoretical model of the casting with the acquired 3D model to obtain the absolute deformation of different deformation parts of the casting.

[0304] S4053: If the deformation of the deformed part of the casting meets the profile requirements, the casting correction shall be terminated.

[0305] S4054: If the deformation of the deformed part of the casting does not meet the profile requirements, return to step 1 until the deformation of the casting meets the profile requirements.

[0306] This method eliminates the need to disassemble internal calibration fixtures; instead, castings are scanned directly to develop a secondary calibration plan.

[0307] The thin-walled casting top-pressure straightening device of the present invention is used to straighten the casting. The deformation correction range is 0.1-8mm, and the single correction accuracy can reach 0.1mm / 40mm. The overall casting deformation correction qualification rate is increased by 5 times, from 26-30 hours / piece to 4-6 hours / piece, which significantly improves the straightening accuracy and efficiency.

[0308] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware, and the program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0309] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for top-pressure shaping of thin-walled castings with irregular cross-sections, characterized in that, Includes the following steps: Step 1: Based on the location distribution of the top pressure correction parts of the casting and the casting size data, adjust the number and installation position of the vertical support frame and the height fixing ring to achieve synchronous correction of all deformed parts; Step 2: Use the casting support beam to fix and clamp the upper and lower ends of the casting; Step 3: Install the direction adjustment support on the height fixed ring. Based on the deformation data of the casting top pressure correction part, adjust the position of the cast iron top pressure head through the rear drive device. Set a cast iron top pressure head at the same deformation part in the inner and outer cavities of the casting to perform positive and negative force correction. The size of the top pressure surface of the cast iron top pressure head is designed according to the effective area of ​​the part of the casting to be corrected. Step 4: Obtain deformation data of the top pressure part of the casting and set the heating temperature of the driving component; The method for obtaining deformation data of the top pressure part of the casting is as follows: the model of the casting to be tested obtained by three-dimensional scanning is aligned with the theoretical casting model for assembly and measurement to obtain the absolute deformation ε of different parts of the casting to be corrected and the main wall thickness t of the part. Based on the relationship between the deformation of the driving component and the temperature, the linear regression equation y = 0.8027x - 37.156 corresponding to the deformation of the driving component and the temperature of the driving component is obtained, where y is the deformation L of the driving component and x is the temperature T of the driving component. The feed rate M of the cast iron top pressure head is the same as the deformation of the driving component. M satisfies M=ε+s, where s is the maximum over-variable value of a single deformation, in order to overcome the influence of springback of the casting surface structure. The maximum over-deformation value s for a single deformation is determined based on the absolute deformation ε at the part of the casting to be corrected and the main wall thickness t at that part. The specific correspondence is as follows: Based on the determined deformation of the driving component, the heating temperature corresponding to the driving component is obtained by combining the linear regression equation. Top-pressure straightening device, rear-end drive device, and high-frequency vibration device for eliminating stress in local straightening areas of castings; The top-pressure calibration device includes a driving component, a transmission component, a cast iron top-pressure head, a support frame, a heat source, and a mounting frame. The heat source, driving component, transmission component, and cast iron top-pressure head are integrated on the support frame. The rear drive device is connected to the support frame and the mounting frame respectively, and is used to adjust the position of the support frame on the mounting frame; During the calibration process, the casting to be calibrated is fixed on the mounting frame, and the heat source control drive component and the deformation extrusion transmission component drive the cast iron top pressure head to press and calibrate the casting surface through the transmission component. The driving component is made of Ni / Ti bidirectional memory alloy and has a spiral shape. The heat source includes a power supply assembly that transmits current to the inside of the driving component. The support frame is equipped with a rear-end temperature measuring thermocouple. The cast iron top pressure head is equipped with a front-end limit switch. The material at the connection between the support frame and the driving component is a heat-insulating high-strength material. The transmission component is also made of a heat-insulating high-strength material. Step 5: Power is supplied to the drive unit via the power supply assembly. The drive unit deforms, causing the cast iron jacking head to act on the surface of the casting to be shaped. The temperature of the drive unit is monitored using a thermocouple at the rear end. When the deformed part of the casting protrudes outward, the cast iron jacking head on the outside of the casting is activated to correct the protruding deformation. The cast iron jacking head inside the casting assists in pressing at the shape to be shaped, preventing twisting deformation near the shape to be shaped. When the deformed part of the casting is concave inward, the cast iron jacking head inside the casting is activated to correct the concave deformation. The cast iron jacking head on the outside of the casting assists in pressing at the shape to be shaped, preventing large-area deformation near the shape to be shaped. The position of the cast iron jacking head is adjusted using a double-column hydraulic arm, ensuring that the cast iron jacking head used for assisting in pressing at the shape to be shaped is always pressed at that shape. Step 6: After the temperature of the driving component reaches the set heating temperature, maintain the temperature for 5-10 seconds. During this process, the cast iron top pressure head used to assist in pressing at the position to be shaped remains fixed relative to the casting. Then disconnect the current. Step 7: Use a high-frequency vibration device to relieve stress on the parts of the casting that are being shaped. Step 8: Re-inspect the calibrated casting until the deformation of the casting meets the contour requirements.

2. The top-pressure shaping method for irregular cross-section thin-walled castings according to claim 1, characterized in that: The working end of the high-frequency vibration device contacts the outer surface of the casting correction part, and performs high-frequency vibration treatment on the casting correction part.

3. The top-pressure shaping method for irregular cross-section thin-walled castings according to claim 1, characterized in that: The rear drive unit includes a direction adjustment support, a double-column hydraulic arm, and a worm gear. One end of the direction adjustment support is connected to the mounting frame, and the other end is fixedly connected to the double-column hydraulic arm; One end of the dual-column hydraulic arm is fixedly connected to the direction adjustment support seat, and the other end is fixedly connected to the worm gear. One end of the worm gear is fixedly connected to the double-column hydraulic arm, and the other end is connected to the support frame.

4. The top-pressure shaping method for thin-walled castings with irregular cross-sections according to claim 3, characterized in that: The double-column hydraulic arm is a primary transmission device, and the worm gear is a secondary transmission device. The extension and retraction direction of the worm gear is consistent with the extension and retraction direction of the double-column hydraulic arm.

5. The top-pressure shaping method for irregular cross-section thin-walled castings according to claim 3, characterized in that: The mounting frame includes a vertical support rod, a height-fixing ring, and a cast support beam; The direction adjustment support is mounted on a height-fixing ring, and the height-fixing ring is mounted on a vertical support rod. The position of the height-fixing ring on the vertical support rod is adjustable.

6. The top-pressure shaping method for thin-walled castings with irregular cross-sections according to claim 1, characterized in that: The deformation state of the drive component varies at different temperatures.

7. The top-pressure shaping method for thin-walled castings with irregular cross-sections according to claim 1, characterized in that: The driving component is a conductor; When the drive component is powered on, its shape changes with the internal temperature of the drive component.

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