Single-point incremental composite hydraulic forming device

Abstract

The invention discloses a single-point increment composite hydraulic forming device which is used for simultaneously forming thin-wall parts with complex shapes with concave-convex characteristics in one-time clamping and comprises single-point increment forming equipment and hydraulic bulging equipment, the single-point increment forming equipment comprises an oil cavity cylinder with an opening in the top, and an upper end cover is arranged on the end face of the top end of the oil cavity cylinder; the middle of the upper end cover is hollow, the edge of a to-be-formed plate is located between the top end of the oil cavity barrel and the upper end cover, a forming tool is arranged above the to-be-formed plate, and the oil cavity barrel is connected with hydraulic bulging equipment. By means of the method, the parts with the concave-convex characteristics and the complex shapes can be formed at the same time in one-time clamping, a mold does not need to be used in the forming process, the number of forming tools does not need to be increased, the sizes and shapes of the forming tools do not need to be replaced, and plates do not need to be turned over.

Description

Technical Field

[0001] The invention belongs to the technical field of metal sheet plastic forming equipment and relates to a single-point incremental composite hydraulic forming device. Background Art

[0002] As a fast and flexible sheet metal forming process, single-point incremental forming technology can form sheet metal into designed thin-walled parts by accumulating deformation point by point using only one forming tool. Compared with traditional stamping and stretching processes, it does not require dedicated molds and fixtures, and has the advantages of high flexibility, high efficiency and low cost. It has broad prospects in the small-batch and multi-variety production of thin-walled parts such as covers, lids, shells and plates in the fields of aerospace, new automobiles, and medical implants. However, without flipping the sheet, using molds, or adding forming tools, single-point incremental forming can only be used for the forming of concave feature parts such as frustums, prisms, and convex curved cones. Summary of the invention

[0003] The object of the present invention is to provide a single-point incremental composite hydraulic forming device, which can simultaneously realize the forming of thin-walled parts with complex shapes and concave-convex features in one clamping.

[0004] The technical solution adopted by the present invention is a single-point incremental composite hydraulic forming device for processing a plate to be formed, including a single-point incremental forming device and a hydraulic bulging device. The single-point incremental forming device includes an oil chamber cylinder with an opening at the top, an upper end cover is provided on the top end face of the oil chamber cylinder, the middle part of the upper end cover is hollow, the edge of the plate to be formed is located between the top end of the oil chamber cylinder and the upper end cover, a forming tool is provided above the plate to be formed, and the oil chamber cylinder is connected to the hydraulic bulging device.

[0005] The present invention is also characterized in that: A buffer pad is arranged between the plate to be formed and the upper end cover.

[0006] A sealing groove is arranged on the top end surface of the oil cavity cylinder, and a sealing ring is arranged in the sealing groove.

[0007] The forming tool is a cylindrical bar stock, a movable ball is arranged at the processing end of the forming tool, an oil funnel is arranged on the side wall of the forming tool, and an oil path is arranged in the forming tool, and the oil path leads from the oil funnel outlet to the movable ball.

[0008] Half of the movable ball body is a hemisphere and the other half is a semi-ellipsoid. The diameter of the hemisphere is equal to the diameter of the long axis of the hemisphere. A round rod shaft is arranged in the movable ball along the straight line where the long axis diameter of the hemi-ellipsoid is located. Both ends of the round rod shaft are fixed to the processing end of the forming tool. The movable ball can rotate with the round rod shaft as the axis. The shape of the processing end of the forming tool matches the hemisphere of the movable ball. When the hemisphere of the movable ball is fully exposed, the hemisphere of the movable ball is completely embedded in the cylindrical rod stock, and the surface of the hemisphere fits the cylindrical rod stock.

[0009] A round zeolite is arranged in the oil funnel.

[0010] The oil chamber cylinder is provided with an oil inlet and an oil outlet. The oil inlet is arranged at a higher height than the oil outlet. The oil inlet and the oil outlet are respectively connected to the hydraulic bulging equipment through high-pressure hoses.

[0011] The hydraulic bulging equipment includes an oil tank, an upper cover plate is arranged on the top of the oil tank, the oil tank is provided with a liquid level gauge, an air filter, and an oil suction filter, the oil suction filter is connected to a plunger pump, the plunger pump is connected to a three-phase asynchronous motor, the plunger pump is connected to one end of a one-way valve, the one-way valve is respectively connected to an overflow valve, a pressure gauge, an accumulator, and a reversing valve through a high-pressure hose, one end of the reversing valve is connected to the overflow valve, the pressure gauge, and the accumulator, the other end of the reversing valve is connected to one end of a stop valve through a high-pressure hose, the other end of the stop valve is connected to the oil inlet of the single-point incremental forming equipment through the high-pressure hose, and the oil outlet of the single-point incremental forming equipment is connected to the inside of the oil tank through the high-pressure hose.

[0012] The beneficial effects of the present invention are: The single-point incremental composite hydraulic forming device of the present invention combines single-point incremental forming and hydraulic bulging. In the single-point incremental forming process, by increasing the hydraulic bulging with a certain pressure, the forming of concave features and convex features can be realized simultaneously in a one-time forming process; the present invention adds a buffer pad between the upper end cover and the plate to be formed, which can prevent the hydraulic oil between the upper end cover and the oil cavity cylinder and the plate from micro-leakage during excessive hydraulic bulging, thereby avoiding obvious wrinkles on the edge of the plate; the end of the forming tool participating in the single-point incremental forming is equipped with a movable ball, and the movable ball composed of a semi-ellipsoid and a semi-sphere can perform alternating rolling on the plate, convert part of the friction resistance into forming power, and improve the lubrication effect; the side wall of the forming tool is provided with an oil funnel, and the lubricating oil in the duckbill oil funnel containing round zeolite can be more accurately, evenly and stably applied to the surface of the plate to be formed through the movable ball, which is conducive to improving the surface quality of the formed part; The accumulator in the hydraulic bulging equipment can store the pressure required for bulging in advance, which is conducive to the quantitative, instantaneous and stable supply of bulging pressure. This design not only realizes thin-walled parts with concave and convex features in one clamping and one forming, but also has good part forming quality, high cost-effectiveness and is easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of the single-point incremental composite hydraulic forming device of the present invention; Figure 2 is a cross-sectional view of a forming tool in a single-point incremental composite hydraulic forming device of the present invention; Figure 3It is a schematic diagram of the deformation process of the single-point incremental composite hydraulic forming device of the present invention; Figure 4 This is a real picture of the single-point incremental composite hydraulic forming device of the present invention when a buffer pad is not added and an oil funnel is added; Figure 5 This is a real picture of the single-point incremental composite hydraulic forming device of the present invention when a buffer pad is added but no oil funnel is added; Figure 6 This is a real picture of the single-point incremental composite hydraulic forming device of the present invention when a buffer pad, an oil funnel and an accumulator are added.

[0014] In the figure, 1. oil chamber cylinder, 2. upper end cover, 3. buffer pad, 4. forming tool, 5. sheet to be formed, 6. sealing ring, 7. oil inlet, 8. oil outlet, 9. movable ball, 10. oil funnel, 11. oil tank, 12. liquid level gauge, 13. air filter, 14. oil suction filter, 15. plunger pump, 16. three-phase asynchronous motor, 17. one-way valve, 18. overflow valve, 19. pressure gauge, 20. accumulator, 21. reversing valve, 22. stop valve, 23. upper cover plate, 24. high-pressure hose, 25. sheet in forming. DETAILED DESCRIPTION

[0015] The present invention is described in detail below in conjunction with the accompanying drawings and specific implementation methods. The described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] Example 1 This embodiment provides a single-point incremental composite hydraulic forming device for processing a circular sheet 5 to be formed with a thickness of less than 5 mm. Figure 1 As shown, it includes a single-point incremental forming device and a hydraulic bulging device. The single-point incremental forming device includes a cylindrical oil cavity tube 1 with an opening at the top. The oil cavity tube 1 is filled with hydraulic oil. An upper end cover 2 is arranged on the top end face of the oil cavity tube 1. The middle part of the upper end cover 2 is hollow. A side wall extends along the outer edge of the upper end cover 2. The inner side of the side wall of the upper end cover 2 is connected to the outer side of the side wall of the oil cavity tube 1 by a thread. The edge of the sheet 5 to be formed is located between the top end of the oil cavity tube 1 and the upper end cover 2. An annular buffer pad 3 is arranged between the sheet 5 to be formed and the upper end cover 2. A sealing groove is arranged on the top end face of the oil cavity tube 1. A sealing ring 6 is arranged in the sealing groove. A forming tool 4 is arranged above the sheet 5 to be formed. The oil cavity tube 1 is connected to the hydraulic bulging device.

[0017] The single-point incremental composite hydraulic forming equipment can not only realize the single-point incremental forming of complex thin-walled plates with concave and convex features, but also prevent micro-leakage of hydraulic oil between the upper end cover 2 and the oil cavity cylinder 1 and the plate to be formed 5 during excessive hydraulic bulging, thereby avoiding wrinkles on the edge of the plate.

[0018] This embodiment only represents a preferred implementation of the single-point incremental composite hydraulic forming device of the present invention. Any forming device designed with similar technical features to the present invention will fall within the protection scope of the single-point incremental composite hydraulic forming device of the present invention.

[0019] Example 2 This embodiment provides a single-point incremental composite hydraulic forming device. Based on the embodiment 1, Figure 2 As shown, the forming tool 4 is a cylindrical rod, and the processing end of the forming tool 4 is equipped with a movable ball 9 through a round rod shaft. A duckbill oil funnel 10 is provided on the side wall of the forming tool 4, and a round zeolite is provided in the oil funnel 10. An oil circuit is provided in the forming tool 4, and the oil circuit leads to the movable ball 9 from the outlet of the oil funnel 10. After the lubricating oil in the duckbill oil funnel 10 is filtered and buffered by the internal round zeolite, it can be applied to the surface of the sheet to be formed more accurately, evenly and stably, which is beneficial to improving the surface quality of the formed parts.

[0020] Half of the ball body of the movable ball 9 is a hemisphere, and the other half is a hemi-ellipsoid. The diameter of the hemisphere is equal to the long diameter of the hemi-ellipsoid. A round rod shaft is arranged along the straight line where the long axis diameter of the hemi-ellipsoid is located in the movable ball 9. Both ends of the round rod shaft are fixed to the processing end of the forming tool 4. The movable ball 9 can rotate with the round rod shaft as the axis. The shape of the processing end of the cylindrical bar material matches the hemisphere of the movable ball 9. When the hemi-ellipsoid of the movable ball 9 is fully exposed, the hemisphere of the movable ball 9 is completely embedded in the cylindrical bar material, and the surface of the hemisphere fits the cylindrical bar material. The movable ball 9 can perform alternating rolling on the plate, thereby reducing the friction between the ball 9 and the plate 5, and increasing the forming power by changing the direction of the friction; at the same time, when the semicircular contour of the movable ball 9 completes contact with the plate 5, it will enter the contact process between the semi-elliptical contour and the plate 5. In this process, there will be a moment of separation between the movable ball 9 and the plate 5, and the lubricating oil will enter the separation gap, thereby improving the lubrication effect.

[0021] This embodiment only represents a preferred implementation of the single-point incremental composite hydraulic forming device of the present invention. Any forming device designed with similar technical features to the present invention will fall within the protection scope of the single-point incremental composite hydraulic forming device of the present invention.

[0022] Example 3 This embodiment provides a single-point incremental composite hydraulic forming device, based on the embodiment 1-2, such as Figure 1As shown, the oil chamber cylinder 1 is provided with an oil inlet 7 and an oil outlet 8. The oil inlet 7 is arranged at a higher height than the oil outlet 8. The oil inlet 7 and the oil outlet 8 are respectively connected to the hydraulic bulging equipment through a high-pressure hose 24.

[0023] The hydraulic bulging equipment includes an oil tank 11, the oil tank 11 is filled with hydraulic oil, the top of the oil tank 11 is provided with an upper cover plate 23 by screws, the oil tank 11 is provided with a liquid level gauge 12, an air filter 13, and an oil suction filter 14, the liquid level gauge 12, the air filter 13, and the oil suction filter 14 are placed inside the oil tank through the reserved holes of the oil tank upper cover plate 23, and the tops of the liquid level gauge 12, the air filter 13, and the oil suction filter 14 are respectively fixed to the upper cover plate 23 by screws, the oil suction filter 14 is connected to a plunger pump 15 arranged inside the oil tank 11, and the plunger pump 15 is connected to a plunger pump 15 located in the oil tank 11. The three-phase asynchronous motor 16 outside the box and the plunger pump 15 are connected to one end of the one-way valve 17, and the one-way valve 17 is respectively connected to the overflow valve 18, the pressure gauge 19, the accumulator 20, and the reversing valve 21 through the high-pressure hose 24. One end of the reversing valve 21 is connected to the overflow valve 18, the pressure gauge 19, and the accumulator 20, and the other end of the reversing valve 21 is connected to one end of the stop valve 22 through the high-pressure hose 24. The other end of the stop valve 22 is connected to the oil inlet 7 of the single-point incremental forming device through the high-pressure hose 24, and the oil outlet 8 of the single-point incremental forming device is connected to the inside of the oil tank 11 through the high-pressure hose 24.

[0024] This embodiment only represents a preferred implementation of the single-point incremental composite hydraulic forming device of the present invention. Any forming device designed with similar technical features to the present invention will fall within the protection scope of the single-point incremental composite hydraulic forming device of the present invention.

[0025] like Figure 3 As shown, the hydraulic bulging equipment can provide a reverse bulging force to the sheet 25 being formed; while providing a smaller bulging pressure to the sheet 25 being formed, the sheet is subjected to single-point incremental forming, and the sheet area not involved in the single-point incremental forming will gradually form convex features under the influence of the bulging pressure and the rebound of the sheet; storing the pressure in the accumulator 20 in advance is conducive to the instantaneous, quantitative and stable supply of the required pressure, avoiding the pressure fluctuations caused by manual pressure adjustment and the extension of the bulging time (inconsistent bulging time will seriously affect the bulging height).

[0026] Compare Figure 4-5 and Figure 6It can be found that when the single-point incremental composite hydraulic forming device of the present invention is formed without a cushion and an oil funnel, wrinkles will appear on the edge of the plate. Because of the oil funnel, the surface quality is acceptable; when the single-point incremental composite hydraulic forming device of the present invention is formed with a cushion but without an oil funnel, the surface quality of the concave features of the plate is low; when the single-point incremental composite hydraulic forming device of the present invention is formed with a cushion, an oil funnel, and an accumulator, the forming quality of the workpiece is the highest. It can be seen that the forming device of the present invention can obtain thin-walled parts with concave features and convex features in one clamping and one forming without using molds, increasing the number of forming tools, flipping the plate, or changing the forming tools, and the workpiece has good forming quality, high cost-effectiveness, and is easy to implement. This combination of equipment realizes the composite forming of single-point incremental forming and hydraulic bulging.

Claims

1. A single-point incremental composite hydraulic forming device for processing a sheet to be formed (5), characterized in that: The invention comprises a single-point incremental forming device and a hydraulic bulging device, wherein the single-point incremental forming device comprises an oil cavity cylinder (1) with an opening at the top, an upper end cover (2) being arranged at the top end face of the oil cavity cylinder (1), the middle part of the upper end cover (2) being hollow, the edge of the sheet material (5) to be formed being located between the top end of the oil cavity cylinder (1) and the upper end cover (2), a forming tool (4) being arranged above the sheet material (5) to be formed, and the oil cavity cylinder (1) being connected to the hydraulic bulging device.

2. The single-point incremental composite hydroforming device according to claim 1, characterized in that: A buffer pad (3) is provided between the plate to be formed (5) and the upper end cover (2).

3. The single-point incremental composite hydroforming device according to claim 1, characterized in that: The top end surface of the oil chamber cylinder (1) is provided with a sealing groove, and a sealing ring (6) is provided in the sealing groove.

4. The single-point incremental composite hydroforming device according to claim 1, characterized in that: The forming tool (4) is a cylindrical bar stock, a movable ball (9) is provided at the processing end of the forming tool (4), an oil funnel (10) is provided on the side wall of the forming tool (4), and an oil path is provided in the forming tool (4), the oil path leading from the outlet of the oil funnel (10) to the movable ball (9).

5. The single-point incremental composite hydroforming device according to claim 4, characterized in that: Half of the movable ball (9) is a hemisphere and the other half is a hemi-ellipsoid. The diameter of the hemisphere is equal to the long diameter of the hemi-ellipsoid. A round rod shaft is arranged in the movable ball (9) along the straight line where the long axis diameter of the hemi-ellipsoid is located. Both ends of the round rod shaft are fixed to the processing end of the forming tool (4). The movable ball (9) can rotate around the round rod shaft. The shape of the processing end of the forming tool (4) matches the hemisphere of the movable ball (9). When the hemi-ellipsoid of the movable ball (9) is completely exposed, the hemisphere of the movable ball (9) is completely embedded in the cylindrical rod material, and the surface of the hemisphere fits the cylindrical rod material.

6. The single-point incremental composite hydroforming device according to claim 4, characterized in that: The oil funnel (10) is provided with round zeolite.

7. The single-point incremental composite hydroforming device according to claim 2, characterized in that: The oil chamber cylinder (1) is provided with an oil inlet (7) and an oil outlet (8), the oil inlet (7) being arranged at a higher height than the oil outlet (8), and the oil inlet (7) and the oil outlet (8) are respectively connected to the hydraulic bulging equipment via a high-pressure hose (24).

8. The single-point incremental composite hydroforming device according to claim 7, characterized in that: The hydraulic bulging equipment comprises an oil tank (11), the top of which is provided with an upper cover plate (23), the oil tank (11) is provided with a liquid level gauge (12), an air filter (13), and an oil suction filter (14), the oil suction filter (14) is connected to a plunger pump (15), the plunger pump (15) is connected to a three-phase asynchronous motor (16), the plunger pump (15) is connected to one end of a one-way valve (17), and the one-way valve (17) is respectively connected to an overflow valve (18) and an air filter (13) through a high-pressure hose (24). A pressure gauge (19), an accumulator (20), and a reversing valve (21); one end of the reversing valve (21) is connected to the overflow valve (18), the pressure gauge (19), and the accumulator (20); the other end of the reversing valve (21) is connected to one end of a stop valve (22) via a high-pressure hose (24); the other end of the stop valve (22) is connected to an oil inlet (7) of a single-point incremental forming device via a high-pressure hose (24); and the oil outlet (8) of the single-point incremental forming device is connected to the interior of an oil tank (11) via a high-pressure hose (24).

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