Flexible positioning and clamping device for making notches on large and medium-sized several-character arc-shaped thin-walled parts and method for making notches

Abstract

The present invention discloses a flexible positioning and clamping device for making notches on large and medium-sized U-shaped thin-walled parts and a method for making notches. The clamping device comprises a base, an arc-shaped positioning plate and an inclined support. The radian of the upper arc surface of the arc-shaped positioning plate is consistent with the radian of the arc-shaped thin-walled part. The arc-shaped positioning plate is vertically fixed on the base through the inclined support. A transverse fixing device and a radial fixing device are further arranged on the arc-shaped positioning plate. The transverse fixing device is used for positioning and clamping the workpiece in the thickness direction, and the radial fixing device is used for fixing the workpiece in the radial direction. The clamping device has reasonable structure, reliable positioning and clamping, effective flame and slag discharging and thermal deformation control, is convenient to use, has strong universality, small part deformation, good consistency, stable and controllable quality. Compared with the original scheme, no notch out-of-tolerance phenomenon occurs in batch production. The processing efficiency of the part notch is increased by about 80%, and the production cost is significantly reduced.

Description

Technical Field

[0001] The invention belongs to the field of post - forming processing of various thin - walled parts in aerospace, and particularly relates to a flexible positioning and clamping device for making notches on large - and - medium - sized U - shaped thin - walled parts and a method for making notches. Background Technique

[0002] In the field of aerospace equipment, the U - shaped thin - walled part is one of the important radial load - bearing parts of the rocket body. Its structural characteristics are thin walls, arc - shaped, with a U - shaped cross - section, different width dimensions, and notches and depressions of different sizes and types distributed along the radial direction to pass through profile - type parts. For a long time, the processing of notches on U - shaped thin - walled parts has adopted processing methods such as cutting and drilling, positioning holes with template drills, and punching with punching dies. This method has large part deformation, poor notch position accuracy, easy generation of cracks during punching, poor product consistency and quality stability, low manufacturing efficiency, high requirements for the skill level of operators, and each type of notch is equipped with a corresponding notch punching die, and each different part is equipped with a corresponding cutting and drilling template. The quantity is large, used frequently but with low utilization rate, which brings difficulties to the management of dies and templates. Moreover, since these have been in use for a long time, the defect rate and scrap rate of such parts have increased, and they no longer meet the production requirements. It is necessary to re - produce notch punching dies and cutting and drilling templates, but the quantity is large and the cost is high.

[0003] Three - dimensional five - axis laser cutting machine tools are a kind of high - end equipment developed in recent years for the sheet metal stamping industry, mainly used for laser cutting of three - dimensional sheet metal components, with the characteristics of high efficiency and high precision. They can be applied to the processing of the outer shape and holes of the final product and can meet the requirements of high - quality and high - efficiency processing. The difficulty of laser cutting the notches of U - shaped arc - shaped thin - walled parts lies in the fact that the width dimensions of the parts are not the same, which brings difficulties to part positioning, controlling cutting deformation, and alignment.

[0004] After retrieval, there are no domestic institutions or scholars publicly disclosing patents related to three - dimensional five - axis laser cutting processing of notches on U - shaped thin - walled parts. The similar existing technologies are all notch punching die processing methods, mainly research carried out around the improvement of die structure, modular structure design of cutting and drilling templates, and process optimization. Relevant articles include: Guo Jianjun et al. published an article named "Improvement of Forming Process of Parts and Design of Notch Punching Dies" in the journal "Forging & Stamping Technology", and Shan Chao et al. published an article named "Modular Structure Design and Application of Cutting and Drilling Templates for Notches of Typical Parts" in "Aerospace Manufacturing Technology".

[0005] To sum up, when processing large - and - medium - sized U - shaped arc - shaped thin - walled parts, the following technical problems need to be solved urgently:

[0006] The laser cutting processing of all notches of thin-walled parts with a "J"-shaped cross-section and an arc less than 95 degrees can be completed by clamping them once; the problems of out-of-tolerance notches, punching breakage, low manufacturing efficiency and low pass rate in the original plan are solved; the problem of large investment in new punching dies and cutting and drilling templates according to the original plan is solved; the processing of notches of "J"-shaped arc thin-walled parts with different widths is solved to achieve flexible production characteristics; the limit deviation of the notch position of "J"-shaped arc thin-walled parts from the theoretical line is guaranteed to be ±1mm, meeting the requirements of stable and controllable quality; reliable radial clamping is achieved, the problem of large notch deviation caused by the difference in arc accuracy of "J"-shaped arc thin-walled parts is solved, and the difficulty of correction is reduced. Summary of the invention

[0007] In order to solve the problems of poor control reliability of processing quality stability of notches of "J"-shaped arc-shaped thin-walled parts, low qualified rate, time-consuming and labor-intensive, complicated process of drilling positioning holes, and large investment in new punching dies and cutting and drilling templates, the present invention fully utilizes the flexibility of the three-dimensional five-axis laser cutting machine and provides a "J"-shaped arc-shaped thin-walled parts flexible positioning and clamping device, which realizes the processing of all notches and holes of "J"-shaped arc-shaped thin-walled parts with different widths by one positioning and clamping, and provides With depression The product positioning device, radial fixing device, positioning devices of different widths and clamping devices of the present invention can significantly improve processing efficiency, reduce investment, reduce labor intensity, effectively control product consistency and quality stability, and significantly improve product quality and qualified rate.

[0008] The specific scheme of the present invention is:

[0009] A flexible positioning clamping device for making notches in large and medium-sized ""-shaped"" arc-shaped thin-walled parts, the clamping device comprising a base, an arc-shaped positioning plate, and an oblique support, the curvature of the upper arc surface of the arc-shaped positioning plate is consistent with the curvature of the arc-shaped thin-walled part, and the arc-shaped positioning plate is vertically fixed to the base through the oblique support; the arc-shaped positioning plate is also provided with a transverse fixing device and a radial fixing device, the transverse fixing device is used for positioning and clamping the part in the thickness direction, and the radial fixing device is used for fixing the part in the radial direction; arc-shaped grooves are provided on both sides of the arc-shaped positioning plate, and a plurality of pairs of positioning pads are provided at intervals in the arc-shaped grooves, and an asbestos board is provided between the positioning pad and the arc-shaped groove.

[0010] The flexible positioning clamping device described in the present invention is used for the production of notches in large and medium-sized "H"-shaped thin-walled parts. In each group of the positioning pads, one side of the positioning pad is provided with a step hole, the other side opposite is provided with a threaded hole, and a through hole is provided at the corresponding position of the arc-shaped positioning plate, and the positioning pads on both sides are fixed to the arc-shaped groove by bolts, and the positioning pads are provided with different thickness specifications, which can be matched according to the different internal dimensions of the workpiece.

[0011] The flexible positioning and clamping device for making notches in large and medium-sized "X"-shaped arc-shaped thin-walled parts described in the present invention is also equipped with a bow-shaped clamp at each set of positioning pads, which can press and fix the "X"-shaped part on the arc-shaped positioning plate; the clamping foot at one end of the bow-shaped clamp is provided with a widened plane, which can be tightly attached to the outer surface of one side of the "X"-shaped part; the clamping foot at the other end of the bow-shaped clamp is provided with a transverse bolt hole, and is equipped with a wide foot bolt, and the "X"-shaped part is pressed from the other side by adjusting the wide foot bolt.

[0012] The flexible positioning clamping device described in the present invention is used for making notches in large and medium-sized "X"-shaped arc-shaped thin-walled parts. The radial fixing device includes a support rod, a tension plate and a steel rod. During installation, the steel rod is passed horizontally under the arc-shaped groove of the arc-shaped positioning plate, and a clamping pad is placed on the "X"-shaped part. The support rod is placed on the clamping pad. The tension plate covers the steel rod and the support rod from both sides at the same time and compresses the part radially.

[0013] The flexible positioning clamping device described in the present invention is used for making notches in large and medium-sized "X"-shaped thin-walled parts. The upper end of the tension plate is provided with a hanging hole, and the lower end is provided with a hook. The two ends of the support rod are respectively inserted into the hanging holes of the two tension plates, and the hooks at the lower ends of the two tension plates hook the two ends of the steel rod to radially fix the workpiece.

[0014] The flexible positioning clamping device described in the present invention is used for the production of notches in large and medium-sized "X"-shaped thin-walled parts. The radial fixing device also includes a clamping pad and a pressing bolt. The clamping pad is placed between the support rod and the workpiece. A transverse screw hole is provided in the middle of the support rod. The pressing bolt is screwed downward from the screw hole of the support rod to press the clamping pad to achieve radial compression of the workpiece.

[0015] The flexible positioning clamping device for making notches in large and medium-sized ""-shaped"" thin-walled parts described in the present invention comprises the following: the oblique support is in the shape of a right-angled triangle, and its two right-angled sides are provided with connecting and fixing skirts, and are fixedly connected to the base and the arc-shaped positioning plate by bolts at the connecting and fixing skirts; the base is provided with a positioning pin hole, and can be fixed to the machine tool workbench by the positioning pin.

[0016] A method for making a notch in a large or medium-sized arc-shaped thin-walled part using a flexible positioning clamping device comprises the following steps:

[0017] Step 1: Use the workpiece notch detection template to mark the notch shape line of the first product; select a positioning pad of corresponding thickness according to the internal dimensions of the workpiece; place the workpiece on the arc-shaped positioning plate, determine the installation position and quantity of the positioning pad and radial fixture, and the installation position of the positioning pad and radial fixture should be between two adjacent notches to be processed;

[0018] Step 2: Remove the workpiece, install the asbestos board in the arc-shaped grooves on both sides of the arc-shaped positioning plate; then install the positioning pad in the arc-shaped groove of the arc-shaped positioning plate;

[0019] Step 3: Insert the steel rod of the radial fixing device into the round hole below the arc-shaped groove of the arc-shaped positioning plate; place the workpiece on the arc-shaped positioning plate again, take the radial fixing device to press the workpiece tightly on the arc-shaped positioning plate; use a bow-shaped clamp to clamp the workpiece in the thickness direction at the position of the positioning backing plate.

[0020] Step 4: Conduct three-dimensional modeling of the workpiece; generate a laser cutting program, perform coordinate transformation, check whether there is interference between the laser cutting head and the device of the present invention and modify the laser cutting program.

[0021] Step 5: Position the program according to the notch contour line drawn in Step 1, record the coordinate points, manually run the cutting program, check whether there is interference between the laser cutting head and the device of the present invention and modify the laser cutting program.

[0022] Step 6: Return to the starting point of the laser cutting program, start the laser cutting program to complete the processing of the first workpiece, and return the laser cutting head to the absolute coordinate origin of the laser machine; remove the workpiece and check the correctness of the notch, and adjust the cutting program as required.

[0023] Step 7: Take the second workpiece and automatically complete the cutting and processing of subsequent products.

[0024] A method for manufacturing a notch of a large and medium-sized U-shaped arc-shaped thin-walled part using a flexible positioning and clamping device according to the present invention. When processing a workpiece with a depression, in Step 1, it further includes the steps of selecting corresponding depression positioning blocks and quantities according to the depression size of the workpiece, and installing the depression positioning blocks at corresponding positions before and after the arc-shaped positioning plate; and placing the workpiece on the arc-shaped positioning plate, aligning the product depression with the depression positioning blocks.

[0025] A method for manufacturing a notch of a large and medium-sized U-shaped arc-shaped thin-walled part using a flexible positioning and clamping device according to the present invention. For workpieces with an arc length of about 90 degrees, the number of backing plates is 4 - 5 pairs, and the number of radial fixing devices should be 3 - 4 places.

[0026] Device composition and principle:

[0027] The device is composed of a base, an arc-shaped positioning plate, an inclined support, a positioning backing plate, a radial fixing device, a special depression positioning block, an asbestos board, a bow-shaped clamp, etc.

[0028] The function of the base is to support the device and parts of the present invention, and it is connected to the machine tool below. The base adopts a flat plate component, provided with a groove, threaded holes, and cylindrical pin holes. The arc-shaped positioning plate is provided with through holes and threaded holes, and the inclined support is provided with through holes. The three are connected into a whole with bolts. The cylindrical pin holes are used for positioning the device of the present invention on the machine tool workbench, ensuring the consistency of the position of the device of the present invention every time it is used.

[0029] The arc surface of the arc-shaped positioning plate serves as the positioning surface for the radial positioning of parts. An arc-shaped groove is provided below the positioning surface, and a through-hole is made in the groove. The positioning pad and asbestos board in the thickness direction are installed in the arc-shaped groove. The positioning pad is used for the positioning and clamping of parts in the thickness direction, and the asbestos board plays a heat insulation role to prevent the laser from damaging the arc-shaped positioning plate and the device from deforming due to heat. The special sunken positioning block is installed below the groove and is used for the arcwise positioning of the "J"-shaped arc-shaped thin-walled parts with sunken parts at the notch. The position is determined according to the product drawing.

[0030] The radial fixing device adopts a pressing structure and is composed of a pressing bolt, a support rod, a pressing pad, a tension plate, and a steel bar. The part is pressed onto the positioning surface of the arc-shaped positioning plate through the pressing bolt and the pressing pad. Through pressing, the error between the part and the positioning surface of the arc-shaped positioning plate can be reduced, avoiding radial deformation of the part during the cutting process, and effectively controlling the product quality.

[0031] The bow-shaped clamp is an externally purchased part. When in use, it cooperates with the front and rear positioning pads to clamp the part from the outside in the thickness direction of the part, playing a role in preventing the part from deforming in the thickness direction during the cutting process.

[0032] Through the above flexible positioning and clamping device and related processing methods, the following beneficial effects can be achieved:

[0033] The device of the present invention has a reasonable structure, reliable positioning and clamping, effective exhaust of flames and slag and control of thermal deformation, is easy to use, and has strong versatility;

[0034] The present invention significantly improves the product quality: Through production verification, the parts have small deformation, good consistency, stable and controllable quality. Compared with the original plan, no notch out-of-tolerance phenomenon occurs in batch production;

[0035] The present invention significantly improves the production efficiency: Compared with the original plan, the drilling process is cancelled, the secondary punching process is cancelled, the time for frequently installing and disassembling the punching die and borrowing the cutting and drilling template is cancelled, and the processing efficiency of the part notch is increased by about 80%;

[0036] The present invention significantly reduces the production cost: Compared with the original plan, the cutting and drilling template is cancelled, the notch punching die is cancelled, saving the cost of newly manufacturing the cutting and drilling template and the notch punching die. After statistics, six sets of commonly used notch punching dies need to be newly manufactured, greatly reducing the manufacturing cost.

[0037] The processing process of the present invention is started with one key, controlled by a program, with low labor intensity, safe and reliable, and has low requirements for the skill level of operators. Description of the Drawings

[0038] Figure 1 Shows the use state of the positioning and clamping device of the present invention Figure 1 ;

[0039] Figure 1-2It is the second use state diagram of the positioning and clamping device of the present invention;

[0040] Figure 1-3 It is the third use state diagram of the positioning and clamping device of the present invention;

[0041] Figure 2-1 It is the partial enlarged view of the lateral fixing device of the positioning and clamping device of the present invention Figure 1 ;

[0042] Figure 2-2 It is the second partial enlarged view of the lateral fixing device of the positioning and clamping device of the present invention;

[0043] Figure 3-1 It is the partial enlarged view of the radial fixing device of the positioning and clamping device of the present invention Figure 1 ;

[0044] Figure 3-2 It is the second partial enlarged view of the radial fixing device of the positioning and clamping device of the present invention;

[0045] Figure 4 It is the partial schematic diagram of the depression positioning device and installation of the positioning and clamping device of the present invention;

[0046] Figure 5 It is the schematic diagram of the non-depression typical workpiece product of the present invention;

[0047] Figure 6 It is the schematic diagram of the typical workpiece product with depression of the present invention.

[0048] Reference numerals: 1 inclined support, 2 base, 3 bow-shaped clamp, 4 arc-shaped positioning plate, 5 positioning backing plate, 6 asbestos board, 7 connecting screw between the arc-shaped positioning plate and the base, 8 steel bar, 9 arc-shaped pressing plate, 10 support rod, 11 top pressure bolt, 12 tension plate, 13 depression positioning block, 14 connecting screw between the depression positioning block and the arc-shaped positioning plate, 15 product outer contour, 16 connecting screw between the inclined support and the arc-shaped positioning plate and the base, 17 positioning pin hole, 18 lifting bolt, 19 product contour to be cut, 41 arc-shaped groove, 42 through hole for installing the positioning backing plate, 43 through hole for the steel bar 8 to pass through, 31 wide-foot bolt matching with the bow-shaped clamp 3. Detailed implementation manners

[0049] In order to make the purpose, technical solutions and advantages of the present invention clearer, the following further details the technology of the present invention in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0050] Based on full consideration of the cutting range of the laser cutting machine tool, the manufacturing cost, production cycle, quality control, and operation convenience of the inventive device, a vertical structure design is adopted. The main structure of the device consists of a base 2, an arc-shaped positioning plate 4, and an inclined support 1. The three are combined into a whole by means of a connection with socket head cap screws, and also equipped with lifting bolts 18 and positioning pin holes 17 for installation, movement, and positioning on the machine tool workbench; on the arc-shaped positioning plate 4, there are installed a thickness-direction positioning backing plate 5, an asbestos board 6, a radial fixing device, a special sunken positioning block 13, and a bow clamp 3, all of which are key accessories of the inventive device and play roles in positioning, clamping, protecting, and slag removal of parts. The main structure is shown in Figure 1 as follows.

[0051] Taking the base 2 as the foundation, the clamping device is adjusted in place on the laser cutting machine workbench so that the positioning pin holes 17 correspond to the pin holes on the workbench, and then positioning pins are inserted for fixation to avoid displacement and improve machining accuracy. Four corresponding lifting bolts 18 are installed on the side of the base. On the upper surface of the base 2, there is a groove (not shown in the figure) arranged according to the contour of the arc-shaped positioning plate 4, and the arc-shaped positioning plate 4 is installed in the groove, which is beneficial to stabilizing the arc-shaped positioning plate 4. The inclined support 1 is installed on the side of the arc-shaped positioning plate 4. The arc-shaped positioning plate 4, the inclined support 1, and the base 2 are connected by bolts. After combination, the base 2 and the arc-shaped positioning plate 4 should be perpendicular to each other;

[0052] The arc-shaped positioning plate 4 is mainly used for installing positioning devices, radial fixing devices, and the asbestos board 6 for protection, realizing the positioning of parts in the radial and thickness directions, realizing the functions of supporting and pressing parts, realizing the consistency of the spatial positions of parts on the laser cutting machine workbench, ensuring that the product positioning accuracy is controllable, and effectively controlling cutting deformation.

[0053] The arc-shaped positioning plate 4 is a flat plate structure. The thickness is determined according to the distance between the minimum inner dimension of the workpiece and the thickness direction of the product and the arc-shaped positioning plate 4. The upper surface is an arc surface, serving as the positioning surface of the workpiece for radial positioning, support, and clamping of the workpiece. The four edges of the arc surface are chamfered to prevent scratching the workpiece. Arc-shaped grooves 41 are made on both sides of the arc-shaped positioning plate 4. The lower arc of the arc-shaped groove 41 is chamfered to facilitate the falling of molten slag. Through holes 42 are arranged at intervals in the arc-shaped groove 41 for installing the positioning backing plate 5 and the asbestos board 6. Threaded holes (not shown in the figure) are arranged outside the arc-shaped groove 41 for installing the sunken positioning block 13, which is only used when machining workpieces with sunken parts. The positions of the threaded holes are designed according to the sunken positions of the product drawings. Through holes 43 are arranged below the arc-shaped groove 41, and steel rods 8 are passed through the through holes 43 for installing the radial fixing device.

[0054] The positioning backing plate 5 is a flat component, symmetrically arranged in the arc-shaped grooves 41 on both sides of the arc-shaped positioning plate 4. One is made with a stepped hole 51, and the other is made with a threaded hole 52. It is installed in the arc-shaped grooves 41 on both sides of the arc-shaped positioning plate 4 with socket head cap screws. Its function is to cooperate with the bow-shaped clamp 3 to achieve positioning and clamping in the thickness direction of the part. The structure is as Figure 2-1 shown. The positioning backing plate 5 needs to be configured with positioning backing plates 5 of different thicknesses according to the internal shape dimensions of different parts, reflecting the flexible manufacturing characteristics of the inventive device.

[0055] At each group of positioning backing plates 5, a bow-shaped clamp 3 is also provided in a supporting manner, which can tightly press and fix the channel-shaped workpiece on the arc-shaped positioning plate 4; one end of the clamping foot of the bow-shaped clamp 3 is provided with a widened plane, which can closely adhere to the outer surface of one side of the channel-shaped workpiece; the other end of the clamping foot of the bow-shaped clamp 3 is provided with a transverse bolt hole (not shown in the figure), and a wide-foot bolt 31 is provided in a supporting manner, and the channel-shaped workpiece is pressed from the other side by adjusting the wide-foot bolt 31.

[0056] The depression positioning block 13 is specially configured for the notch containing a depression, which is an extension of the function of the inventive device. Its function is to be used for the circumferential positioning of the "channel" arc-shaped thin-walled workpiece containing a depression. It is installed on the threaded holes in the arc-shaped grooves 41 on both sides of the arc-shaped positioning plate 4 with socket head cap screws, and its position is determined according to the product drawing.

[0057] The radial fixing device is composed of a pressing bolt 11, a support rod 10, a tension plate 12, an arc-shaped pressing plate 9 and a steel bar 8. It is installed on the outside of the workpiece together with the bow-shaped clamp 3. The installation position should be between two adjacent notches. The function of this device is to achieve radial pressing of the workpiece, prevent radial deformation during the cutting process and eliminate the manufacturing error of the arc of the workpiece, ensure reliable positioning and clamping of the workpiece, and the device should be avoided during programming to prevent interference and contact with the laser cutting head.

[0058] The asbestos board 6 is a segmented arc-shaped component, and the radial width dimension is slightly smaller than the groove width of the arc-shaped groove 41 of the arc-shaped positioning plate 4. It is installed in the arc-shaped grooves of adjacent positioning backing plates 5 with screws and nuts, and is used for heat insulation and blocking laser from damaging the inventive device, preventing the device from being deformed by heat and affecting the positioning accuracy and cutting quality of the workpiece. The asbestos board 6 needs to be installed under each notch and hole to be cut.

[0059] For workpieces without depressions, the method for making notches of large and medium-sized channel arc-shaped thin-walled workpieces using the flexible positioning and clamping device is as follows:

[0060] 1. Use the workpiece notch detection template to mark the notch shape line of the first-piece product;

[0061] 2. Select the positioning backing plate 5 with the corresponding thickness according to the internal shape dimensions of the workpiece;

[0062] 3. Place the workpiece on the arc-shaped positioning plate 4, determine the installation positions and quantities of the positioning backing plate 5 and the radial fixing device. The installation positions of the positioning backing plate 5 and the radial fixing device should be between two adjacent notches. For a workpiece with an arc length of about 90 degrees, the number of pairs of backing plates is 4 - 5 pairs, and the number of radial fixing devices should be 3 - 4 places.

[0063] 4. Remove the workpiece, install the positioning backing plate 5 in the arc-shaped groove 41 of the arc-shaped positioning plate 4, and insert the steel rod 8 of the radial fixing device into the through hole 43 below the arc-shaped groove of the arc-shaped positioning plate 4.

[0064] 5. Install the asbestos board 6 in the arc-shaped grooves 41 on both sides of the arc-shaped positioning plate 4.

[0065] 6. Place the workpiece on the arc-shaped positioning plate 4, and use the radial fixing device to press the workpiece tightly on the arc-shaped positioning plate 4.

[0066] 7. Use the bow-shaped clamp 3 to clamp the workpiece in the thickness direction at the position of the positioning backing plate 5.

[0067] 8. Perform three-dimensional modeling of the workpiece; generate a laser cutting program, perform coordinate transformation, check whether there is interference between the laser cutting head and this device and modify the laser cutting program; position the program with the notch contour line drawn in step 1, record the coordinate points, manually run the cutting program, check whether there is interference between the laser cutting head and the inventive device and modify the laser cutting program.

[0068] 9. Return to the starting point of the laser cutting program, start the laser cutting program to complete the processing of the first piece, and return the laser cutting head to the absolute coordinate origin of the laser machine.

[0069] 10. Take the workpiece and check the correctness of the notch, and adjust the cutting program as needed.

[0070] 11. Take the second workpiece and automatically complete the cutting and subsequent product processing.

[0071] For the processing method of workpieces with sinks, the difference lies in:

[0072] In step 3, it also includes: Select the corresponding sink positioning blocks 13 and the quantity according to the sink size of the workpiece, and install the corresponding sink positioning blocks 13 on both sides of the arc-shaped positioning plate 4; place the workpiece on the arc-shaped positioning plate 4, and align the sink of the product with the sink positioning blocks.

[0073] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. It should be noted that any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A flexible positioning and clamping device for making notches on large and medium-sized U-shaped thin-walled parts, characterized in that: The clamping device comprises a base, an arc-shaped positioning plate, an oblique support, a transverse fixing device and a radial fixing device; the curvature of the upper arc surface of the arc-shaped positioning plate is consistent with the curvature of the arc-shaped thin-walled part, and the arc-shaped positioning plate is vertically fixed to the base through the oblique support; the transverse fixing device is used for positioning and clamping the workpiece in the thickness direction, and the radial fixing device is used for fixing the workpiece in the radial direction; arc-shaped grooves are provided on both sides of the arc-shaped positioning plate, and a plurality of pairs of positioning pads are provided at intervals in the arc-shaped grooves, and an asbestos board is provided between the positioning pad and the arc-shaped groove; The radial fixing device includes a support rod, a tension plate and a steel rod. When installing, the steel rod is passed horizontally from below the arc-shaped groove of the arc-shaped positioning plate, the pressing pad is placed on the "X"-shaped component, the support rod is placed on the pressing pad, the tension plate covers the steel rod and the support rod from both sides at the same time, and radially presses the component; In each group of the positioning plates, one side of the positioning plates is provided with a step hole, the other side opposite is provided with a threaded hole, and a through hole is provided at the corresponding position of the arc-shaped positioning plate, and the positioning plates on both sides are fixed to the arc-shaped groove by bolts, and the positioning plates are provided with different thickness specifications, which can be matched according to the different internal dimensions of the workpiece.

2. The flexible positioning and clamping device for making notches of large and medium-sized U-shaped thin-walled parts according to claim 1, characterized in that: A bow-shaped clamp is also provided at each set of positioning pads, which can press and fix the "X"-shaped component on the arc-shaped positioning plate; a clamping foot at one end of the bow-shaped clamp is provided with a widened plane, which can be close to the outer surface of one side of the "X"-shaped component; a clamping foot at the other end of the bow-shaped clamp is provided with a transverse bolt hole, and a wide foot bolt is provided, and the "X"-shaped component can be pressed from the other side by adjusting the wide foot bolt.

3. The flexible positioning and clamping device for making notches of large and medium-sized arc-shaped thin-walled parts in the shape of Chinese character "ji", according to claim 1, is characterized in that: The upper end of the tension plate is provided with a hanging hole, and the lower end is provided with a hook. The two ends of the support rod are respectively inserted into the hanging holes of the two tension plates, and the hooks at the lower ends of the two tension plates hook the two ends of the steel rod to radially fix the workpiece.

4. The flexible positioning and clamping device for making notches of large and medium-sized U-shaped thin-walled parts according to claim 3, wherein: The radial fixing device also includes a pressing bolt, and the clamping pad is placed between the support rod and the workpiece. A transverse screw hole is provided in the middle of the support rod. The pressing bolt is screwed downward from the screw hole of the support rod to press the clamping pad to achieve radial compression of the workpiece.

5. The flexible positioning and clamping device for making notches of large and medium-sized arc-shaped thin-walled parts in the shape of a Chinese character 'ji', characterized in that: The inclined support is in the shape of a right-angled triangle, and its two right-angled sides are provided with connecting and fixing skirts, and are fixedly connected to the base and the arc-shaped positioning plate by bolts at the connecting and fixing skirts; a positioning pin hole is provided on the base, and it can be fixed on the machine tool workbench by the positioning pin.

6. A method for making a notch in a large or medium-sized arc-shaped thin-walled part using a flexible positioning clamping device comprises the following steps: Step 1: Use the workpiece notch detection template to mark the notch shape line of the first product; select a positioning pad of corresponding thickness according to the internal dimensions of the workpiece; place the workpiece on the arc-shaped positioning plate, determine the installation position and quantity of the positioning pad and radial fixture, and the installation position of the positioning pad and radial fixture should be between two adjacent notches to be processed; Step 2: Remove the workpiece, install the asbestos board in the arc-shaped grooves on both sides of the arc-shaped positioning plate; then install the positioning pad in the arc-shaped groove of the arc-shaped positioning plate; Step 3: Insert the steel bar of the radial fixing device into the through hole below the arc-shaped groove of the arc-shaped positioning plate; place the workpiece on the arc-shaped positioning plate again, take the radial fixing device to press the workpiece tightly on the arc-shaped positioning plate; use a bow clamp to clamp the workpiece in the thickness direction at the position of the positioning backing plate. Step 4: Three-dimensional modeling of the workpiece; generate a laser cutting program, perform coordinate transformation, check whether there is interference between the laser cutting head and the flexible positioning and clamping device, and modify the laser cutting program. Step 5: Position the program with the notch contour line drawn in Step 1, record the coordinate points, manually run the cutting program, check whether there is interference between the laser cutting head and the flexible positioning and clamping device, and modify the laser cutting program. Step 6: Return to the starting point of the laser cutting program, start the laser cutting program to complete the processing of the first piece, and return the laser cutting head to the absolute coordinate origin of the laser machine; remove the workpiece and check the correctness of the notch, and adjust the cutting program as required. Step 7: Take the second workpiece and automatically complete the cutting and subsequent product processing.

7. The manufacturing method of the notch of a large and medium-sized U-shaped thin-walled part using a flexible positioning and clamping device according to claim 6, characterized in that: When processing workpieces with depressions, In Step 1, it also includes the step of selecting corresponding depression positioning blocks and quantities according to the depression dimensions of the workpiece, and installing the depression positioning blocks at the corresponding positions before and after the arc-shaped positioning plate; place the workpiece on the arc-shaped positioning plate, and align the product depression with the depression positioning blocks.

8. The manufacturing method of the notch of a large and medium-sized U-shaped thin-walled part using a flexible positioning and clamping device according to claim 7, characterized in that: For workpieces with an arc length of about 90 degrees, the number of backing plates is 4 - 5 pairs, and the number of radial fixing devices should be 3 - 4 places.

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