CN118321426B - Partitioned time-by-time type electric auxiliary forming device and process for hemispherical shell - Google Patents

Abstract

The present invention discloses a partitioned time-by-time electric-assisted forming device and process for hemispherical shell parts, the forming device comprises a base plate assembly, a die assembly, a clamping assembly, a punch assembly, a hanging plate assembly fixedly connected to the top of the punch assembly and connected to the stamping power end; the die assembly comprises a die center column, a die ring assembly, and a die dot matrix electrode, the die ring assembly and the top surface of the die center column constitute a continuous hemispherical concave arc surface; the punch assembly comprises a punch center column, a punch ring assembly, and a punch dot matrix electrode, the punch ring assembly and the bottom surface of the punch center column constitute a continuous hemispherical convex arc surface. The present invention adopts an annular partitioning and time-by-time variable power-on mode, and different currents are passed into different thinning areas of the slab to make the thinning degree of each area tend to be consistent; each functional component adopts a detachable assembly structure, which is convenient for local replacement when a local area is damaged.

Description

Partitioned time-by-time electric auxiliary forming device and process for hemispherical shell parts

Technical Field

The invention relates to the technical field of metal stamping forming, and in particular to a zoned, time-by-time electric-assisted forming device and process for hemispherical shell parts.

Background Art

The large-size annular tank is the core component of the next-generation long-term on-orbit upper stage. Compared with the previous upper stage spherical tank, it has the advantages of high structural efficiency and large spatial volume, and can greatly improve the upper stage carrying capacity. In the future, this type of annular tank will need to be in orbit for a long time for ≥6 months under variable temperatures of -120 to 120°C and high stress. The service conditions are harsh, which puts an urgent demand on high-performance annular tanks.

The above-mentioned annular tank is usually large in size, so it is currently formed by splicing two hemispherical shells. The hemispherical shell is made by hot stamping, but the traditional hot forming process has the following shortcomings: First, the stamped blank needs to be heated for a long time at a temperature of 750°C or above, which is prone to grain coarsening and performance degradation, and cannot be regulated by subsequent heat treatment, resulting in a large surface roughness of the workpiece, and harmful effects such as oxidation and hydrogen absorption; secondly, the manufacturing cost of large vacuum hot pressing equipment and high-temperature resistant molds is extremely high. Once the mold is partially damaged, the mold must be replaced as a whole, which is too costly; thirdly, after the blank is heated at the heating station, it needs to be transferred to the stamping station. The transfer process takes a long time, and the temperature of the blank will drop rapidly, which is prone to surface oxidation and hydrogen absorption reactions.

Summary of the invention

The present invention proposes a partitioned hourly electric-assisted forming device and process for hemispherical shell parts, which adopts the method of power-assisted heating to achieve rapid heating of the plate blank, and at the same time adopts an annular partitioning and hourly variable power-on method to pass different and gradually decreasing currents into different thinning areas of the plate blank to make the thinning degree of each area tend to be consistent; the forming device is assembled from die assembly units, which is convenient for local replacement when a local area is damaged.

In order to solve the above technical problems, a technical solution adopted by the present invention is:

A zoned, time-by-time electric-assisted forming device for hemispherical shell parts, comprising a base plate assembly, a die assembly fixedly arranged on the top surface of the base plate assembly, a plurality of clamping assemblies fixedly arranged on the top surface of the base plate assembly and evenly distributed on the outside of the die assembly, a male die assembly coaxially arranged just above the female die assembly, and a hanging plate assembly fixedly connected to the top of the male die assembly and connected to a stamping power end;

The die assembly comprises a die central column, a plurality of die annular components coaxially and adjacently sleeved on the outer side of the die central column, each die annular component is composed of a plurality of die assembly units adjacently spliced in sequence, a die dot matrix electrode is movably inserted in the die central column and each die assembly unit, the outer surfaces of two adjacent die assembly units located in the outermost ring are connected and positioned by a first connecting plate, the top surfaces of the die assembly units in the same die annular component form a continuous annular curved surface, and the annular curved surfaces of different die annular components and the top surface of the die central column form a continuous hemispherical concave arc surface;

The punch assembly comprises a punch center cylinder, a plurality of punch annular assemblies coaxially and adjacently sleeved on the outer side of the punch center cylinder, each punch annular assembly is composed of a plurality of punch assembly units adjacently spliced in sequence, a punch dot matrix electrode is movably inserted in the punch center cylinder and each punch assembly unit, the outer surfaces of two adjacent punch assembly units located in the outermost ring are connected and positioned by a second connecting plate, the bottom surfaces of the punch assembly units in the same punch annular assembly form a continuous annular curved surface, and the annular curved surfaces of different punch annular assemblies and the bottom surface of the punch center cylinder form a continuous hemispherical convex arc surface;

The sheet blank to be formed is fixed on the top surface of the die assembly by the clamping assembly, the edge of the sheet blank is connected to an output electrode of an external power supply device, and the punch dot matrix electrode is connected to another electrode of the external power supply device. During the downward movement of the punch assembly, stamping pressure is applied to the sheet blank to cause the sheet blank to be drawn and deformed. The punch dot matrix electrode contacts the top surface of the sheet blank ring by ring from the inside to the outside, and within a preset time period after the punch dot matrix electrodes of each ring contact the surface of the sheet blank, the current passing through the punch dot matrix electrode gradually decreases. After the sheet blank is stretched and deformed until its bottom surface is completely in contact with the hemispherical concave arc surface of the die assembly, the output electrode connected to the edge of the sheet blank is switched to be connected to the die dot matrix electrode, and the punch assembly cooperates with the die assembly to keep the semi-formed part for a preset time. Within the preset time period, the punch dot matrix electrode cooperates with the die dot matrix electrode to energize the semi-formed part for stress relaxation.

Furthermore, the die assembly unit includes a die support and a die area forming die, the top surface of the die support is provided with a plug-in groove, the bottom surface of the die area forming die is integrally provided with a plug-in block, the plug-in block is plug-fitted with the plug-in groove and fastened by screws.

Furthermore, a vertically arranged through hole is opened in the forming mold of the die area, the die dot matrix electrode is located in the through hole, a rebound part mounting hole connected to the through hole is opened on the bottom surface of the die support member, a rebound part is movably arranged in the rebound part mounting hole, and the bottom end of the die dot matrix electrode can be detachably plugged into the top end of the rebound part.

Furthermore, a stopper is fixedly connected in the installation hole of the resilient member, the bottom end of the resilient member movably passes through the stopper, and a spring is arranged between the resilient member and the stopper.

Furthermore, a mounting operation hole connected to the resilient component mounting hole and located below the stopper is formed on the side wall of the die support, and the outline dimension of the mounting operation hole is larger than the outline dimension of the stopper.

Furthermore, a threading groove is provided on the bottom surface of the die support.

Furthermore, at least one set of connecting columns is fixedly provided on the outer side surface of the forming die in the die area of the outermost ring, and the two ends of the first connecting plate are movably connected to the connecting columns on the two adjacent die areas of the outermost ring.

Furthermore, the clamping assembly includes two support columns, a guide support plate fixedly arranged on the top ends of the two support columns, a movable support plate slidably embedded in the top surface of the guide support plate, and a cylinder bracket fixedly connected to the top surface of the movable support plate. At least one positioning cylinder is fixedly arranged on the bottom surface of the guide support plate, and the output rod end of the positioning cylinder is connected to the side wall of the movable support plate. At least one clamping cylinder is fixedly arranged on the top surface of the cylinder bracket, and the output rod end of the clamping cylinder is fixedly connected to a clamping electrode plate.

Furthermore, the substrate assembly includes multiple substrate units and multiple substrate connecting parts. The multiple substrate unit units are spliced in sequence to form a square flat plate structure, and the top of the square flat plate structure is spliced to form a circular mounting groove. Two adjacent substrate unit units are connected by a substrate connecting part, and the substrate connecting part and the substrate unit units are connected by screws.

Furthermore, the hanger plate assembly includes multiple hanger plate units, multiple hanger plate connecting parts and a power hanging part. The multiple hanger plate units are spliced in sequence to form a circular flat plate structure. Two adjacent hanger plate units are connected by at least two hanger plate connecting parts. The hanger plate connecting parts and the hanger plate units are connected by screws. The power hanging part is fixedly connected to the center of the top surface of the circular flat plate structure by screws.

A partitioned, time-based, electrically assisted forming process for a hemispherical shell is also provided, and the partitioned, time-based, electrically assisted forming device for the hemispherical shell includes the following steps:

S1, placing the plate blank to be formed on the top surface of the die assembly, and clamping and fixing each edge of the plate blank by each clamping assembly;

S2, connecting the edge of the plate blank to an output electrode of the external power supply device through the clamping assembly, connecting each punch matrix electrode to another electrode of the external power supply device, and starting the external power supply device;

S3, the punch power end drives the punch assembly to move downward until the punch dot matrix electrode in the punch center column contacts the center of the top surface of the plate blank, and a preset current is passed into the plate blank through the electrodes connected to the punch dot matrix electrode and the edge of the plate blank, so that the plate blank is energized and heated to a preset forming temperature;

S4, the punch assembly continues to move downward, applying a deformation force to the center of the sheet blank, the sheet blank begins to be drawn and deformed, and the current passing through the punch lattice electrode in the punch center column gradually decreases until the top surface of the sheet blank contacts the punch lattice electrode in the punch assembly unit of an adjacent outer ring, and a preset current is passed into the sheet blank through the punch lattice electrode of the ring and the electrode connected to the edge of the sheet blank to compensate for the heat loss of the sheet blank, so that the sheet blank is energized again and heated to a preset forming temperature;

S5, repeating the process of step S4 until the top surface of the plate blank contacts the punch matrix electrodes in the outermost ring of punch assembly units and the heat dissipation temperature compensation process of the plate blank is completed;

S6, the male die assembly continues to move downward, so that the plate blank is drawn to the maximum position to form a semi-formed part. At this time, the bottom surface of the semi-formed part fits with the hemispherical concave arc surface of the female die assembly and contacts with the end of each female die dot matrix electrode;

S7, the clamping assembly releases the edge clamping part of the plate blank, disconnects the plate blank from the output electrode of the external power supply device, and switches the output electrode to connect with the die matrix electrode, and energizes the semi-formed part through the cooperation of the male die matrix electrode and the female die matrix electrode to quickly heat up the semi-formed part, thereby completing stress relaxation of the semi-formed part in a pressure-maintained state;

S8. The external power supply equipment stops working, and the punch power end drives the punch assembly to rise and reset. After the semi-formed part cools down, the semi-formed part is taken out from the die assembly, and the remaining material on the top edge of the semi-formed part is cut and polished to form a hemispherical shell.

Compared with the prior art, the beneficial effects of the present invention are as follows:

1. The present invention realizes rapid heating of the plate blank by adopting the method of power-on auxiliary heating, which can avoid the plate blank being in a heated state for a long time, avoid grain coarsening and performance degradation of the material, thereby making the surface forming quality of the semi-formed part better and the modeling accuracy higher;

2. The present invention adopts an annular partitioning and time-variable power-on mode, and performs power-on of different thinning areas of the plate blank in annular partitions in sequence to compensate for the heat loss of the corresponding annular partitioned plate blank, so that the plate blank is kept in the forming temperature range in the annular partition, and at the same time, different currents are passed according to the different drawing and thinning amounts of different annular partitions to make the thinning degree of each area tend to be consistent, and in the power-on drawing process of a single annular partition, the current passed is gradually reduced to reduce the Joule heat caused by the drawing and thinning of the plate blank, so as to improve the uniformity of the overall deformation during the plate blank stamping process, avoid premature rupture of the drawing area due to short-term excessive temperature, thereby improving the overall performance of the formed product;

3. The present invention completes the preheating of the slab before forming and the electric heating during the stamping process at the stamping forming station, without the need to transfer the position of the slab. The forming operation is directly carried out after preheating, and the slab is continuously heated synchronously during the forming process, so that the temperature of the slab is kept in a stable forming temperature range, so that the slab is always in a good forming performance state, and the oxidation and hydrogen absorption reaction on the surface of the slab are avoided due to the rapid drop in the temperature of the slab;

4. The forming device of the present invention is assembled from concave mold component units, which is convenient for local replacement when a local area is damaged. The assembly and disassembly operations of the device are relatively easy, thereby reducing the production, maintenance, transfer and other use costs of the mold.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of a three-dimensional structure of the present invention;

FIG2 is a second schematic diagram of the three-dimensional structure of the present invention;

FIG3 is a schematic diagram of a top view of the structure of the present invention;

FIG4 is a schematic diagram of the three-dimensional structure of the present invention in a clamping plate blank state;

FIG5 is a schematic diagram of a three-dimensional structure of the substrate assembly;

FIG6 is a second schematic diagram of the three-dimensional structure of the substrate assembly;

FIG7 is one of the three-dimensional structural schematic diagrams of the female mold assembly;

FIG8 is a second schematic diagram of the three-dimensional structure of the female mold assembly;

FIG9 is a schematic diagram of the top view of the structure of the female mold assembly;

FIG10 is one of the three-dimensional structural schematic diagrams of the female mold assembly unit;

FIG11 is a second schematic diagram of the three-dimensional structure of the female mold assembly unit;

FIG12 is a schematic cross-sectional view of the die assembly unit;

FIG13 is a schematic diagram of a three-dimensional structure of the die support member;

FIG14 is a second schematic diagram of the three-dimensional structure of the die support;

FIG15 is one of the three-dimensional structural schematic diagrams of the forming die in the concave die area;

FIG16 is a second schematic diagram of the three-dimensional structure of the forming die in the concave die area;

FIG17 is a schematic diagram of a three-dimensional structure of the male mold assembly;

FIG18 is a second schematic diagram of the three-dimensional structure of the male mold assembly;

FIG19 is a perspective view of the structure of the hanging plate assembly;

FIG20 is a schematic diagram of a three-dimensional structure of the clamping assembly;

FIG. 21 is a second schematic diagram of the three-dimensional structure of the clamping assembly.

In the figure: 1, substrate assembly; 11, substrate unit component; 12, substrate connector; 2, clamping assembly; 21, support column; 22, guide support plate; 23, movable support plate; 24, cylinder bracket; 25, positioning cylinder; 26, clamping cylinder; 27, clamping electrode plate; 3, die assembly; 31, die center column; 32, die assembly unit; 321, die support; 3211, threading slot; 3212, installation operation hole; 3213, first screw hole; 3214, second screw hole; 3215, plug-in slot; 3216, connecting hole; 3217 , springback mounting hole; 322, forming die in die area; 3221, plug-in block; 3222, threaded connection hole; 3223, through hole; 3224, connecting column; 3225, forming surface in die area; 323, springback; 324, stopper; 325, spring; 33, die lattice electrode; 4, punch assembly; 41, punch center column; 42, punch assembly unit; 43, punch lattice electrode; 5, first connecting plate; 6, second connecting plate; 7, plate blank; 8, hanger plate assembly; 81, hanger plate unit; 82, hanger plate connecting piece; 83, power hook-up piece.

DETAILED DESCRIPTION

The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

It should be noted that when a component is referred to as being "mounted on" another component, it may be directly on the other component or there may be a central component. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be a central component at the same time. When a component is considered to be "fixed to" another component, it may be directly fixed on the other component or there may be a central component at the same time.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "or/and" used herein includes any and all combinations of one or more related listed items.

Please refer to Figures 1 to 21, a partitioned, time-by-time electric-assisted forming device for hemispherical shell parts includes a base plate assembly 1, a die assembly 3 fixedly arranged on the top surface of the base plate assembly 1, a plurality of clamping assemblies 2 fixedly arranged on the top surface of the base plate assembly 1 and evenly distributed on the outside of the die assembly 3, a punch assembly 4 coaxially arranged directly above the die assembly 3, and a hanging plate assembly 8 fixedly connected to the top of the punch assembly 4 and connected to the stamping power end. During the forming operation, the clamping assembly 2 clamps and fixes the edge of the plate blank 7 so that the plate blank 7 is fixedly set on the top surface of the die assembly 3, and the stamping power end drives the punch assembly 4 to move downward through the hanging plate assembly 8, and then cooperates with the die assembly 3 to complete the deep drawing of the plate blank 7; before starting the deep drawing, the plate blank 7 is electrically heated by the cooperation of the punch assembly 4 and the clamping assembly 2, so that the plate blank 7 is heated to a state with better forming performance; during the deep drawing process, the plate blank 7 is electrically heated from the inside to the outside ring by ring through the punch assembly 4, so that the forming characteristics of the plate blank 7 are reduced due to the lower temperature on the inner side of the energized annular area. , the annular area is in the best forming state and completes local drawing, so that the forming characteristics and thinning degree of each annular area are consistent; the current in a certain annular area is also gradually reduced. When the next annular area of the plate blank 7 is in the energized heating state, the previous annular area stops energizing. In this way, during the continuous drawing and thinning process of the plate blank 7 in the annular area, the current passing through the plate blank 7 in the annular area is also reduced synchronously, so as to reversely inhibit the increase of Joule heat caused by the thinning of the plate blank 7, so that the plate blank 7 is always in a relatively stable forming temperature range, avoiding the slab from cracking due to excessive local temperature.

Since the forming object used by the electric-assisted forming device is relatively large, the volume and weight of the corresponding functional components are relatively large. If each functional component adopts an integral structure, there will be problems of inconvenience in transfer and assembly. In addition, due to the high requirements on the forming quality of the formed part, once the functional component (especially the forming part) is partially damaged, the corresponding functional component needs to be replaced as a whole. There are still problems of time-consuming and labor-intensive disassembly and assembly. At the same time, the integral structure also has problems of difficult processing and high use cost. Based on the above problems, each function of the present invention adopts a detachable assembly structure, which is convenient for the assembly and disassembly of each functional component, especially when a certain assembly unit in the functional component is damaged, it can be directly replaced in situ, and it is convenient for storage and transfer after overall disassembly, which effectively reduces the maintenance and use costs.

The specific structure and use process of each functional component of the present invention are described in detail below.

As shown in Fig. 5 and Fig. 6, the substrate assembly 1 includes a plurality of (four in this embodiment) substrate units 11 and a plurality of (correspondingly four) substrate connectors 12. The plurality of substrate units 11 are sequentially spliced to form a square flat plate structure, and the top of the square flat plate structure is spliced to form a circular ring-shaped embedding groove. Two adjacent substrate units 11 are connected by the substrate connector 12, and the substrate connector 12 is connected to the substrate unit 11 by screws. In this way, the substrate assembly 1 forms a fixed integral structure for the installation and fixation of the die assembly 3, so the inner diameter of the circular ring-shaped embedding groove formed on its top surface matches the outer diameter of the die assembly 3.

As shown in Figures 7 to 9, the die assembly 3 is cylindrical in shape as a whole, and a die forming surface for deep drawing is arranged at the center of the top surface. Specifically, the die assembly 3 includes a die center column 31, a plurality of die ring components coaxially and adjacently arranged on the outside of the die center column 31, and each die ring component is composed of a plurality of die component units 32 adjacently spliced in sequence, that is, the whole die assembly is divided into a plurality of ring columns by a plurality of vertically coaxially arranged and equidistant cylindrical surfaces, and then each ring column is further divided into a plurality of block columns by a plurality of vertical planes uniformly distributed around the axis of the ring column and passing through the axis, and each block body corresponds to a die component unit 32. The die center column 31 and each die component unit 32 are movably inserted with a die dot matrix electrode 33, and the outer surfaces of the two adjacent die component units 32 located in the outermost ring are connected and positioned by the first connecting plate 5.

Further, as shown in FIGS. 10 to 12 , the die assembly unit 32 includes a die support 321 and a die area forming die 322. The die area forming die 322 corresponds to a section having a curved surface at the top of the block column, and the die support 321 corresponds to a vertical section at the bottom of the block column. The inner surface (die area forming curved surface 3225) of the area forming die 32 in the same die annular assembly constitutes a continuous annular curved surface, and each annular curved surface of different die annular assemblies constitutes a continuous hemispherical concave arc surface. A die lattice electrode 33 is arranged in each die area forming die 322, so that the die lattice electrode 33 constitutes a spatial lattice structure in which each layer is annularly distributed, distributed downward layer by layer, and contracted inward layer by layer. If the resistance values of the respective die dot matrix electrodes 33 in the same die annular component are the same, then when the input voltage is the same, the current passing through the drawing area of the sheet blank 7 corresponding to the die annular component is also the same, even if the forming performances of the sheet blank 7 at various locations within the same annular area are in the same state; if the resistance values of the respective die dot matrix electrodes 33 in different die annular components gradually increase from the inside to the outside, then during the process of rapid power-on and temperature increase for stress relaxation after the sheet blank 7 is completed through deep drawing, a temperature distribution gradually decreasing from the inside to the outside can be formed in the semi-finished formed part within the same power-on time, so that the center where the drawing stress is the largest obtains the greatest degree of stress relaxation, and the edge where the drawing stress is the smallest obtains a smaller degree of stress relaxation.

Specifically, as shown in Figures 13 to 16, a plug-in slot 3215 is provided on the top surface of the die support 321, and at least one (two as shown in Figure 13) second screw hole 3214 is provided on the outer wall of the plug-in slot 3215. A plug-in block 3221 matching the outer contour of the plug-in slot 3215 is integrally provided on the bottom surface of the die area forming mold 322, and a threaded connection hole 3222 is provided on the side of the plug-in block 3221. After the plug-in block 3221 is plugged into the plug-in slot 3215, the threaded connection holes 3222 are respectively matched with the second screw holes 3214, and then fastened by screw connection, so that the plug-in block 3221 and the support body 321 are fixedly connected as a whole.

A vertically arranged through hole 3223 is opened in the die area forming die 322, and the die dot matrix electrode 33 is located in the through hole 3223, so that the top end of the die dot matrix electrode 33 protrudes above the die area forming curved surface 3225 when it is not in working state. After the sheet blank 7 is deep drawn and deformed, the bottom surface of the sheet blank 7 contacts the top end of the die dot matrix electrode 33 before contacting the die area forming curved surface 3225. After the bottom surface of the sheet blank 7 is completely fitted with the die area forming curved surface 3225, the die dot matrix electrode 33 descends along the through hole 3223 until its top end is located in the die area forming curved surface 3225.

The bottom surface of the die support 321 is provided with a resilient member installation hole 3217 connected to the through hole 3223, and a resilient member 323 is movably arranged in the resilient member installation hole 3217, and the bottom end of the die dot matrix electrode 33 is detachably plugged into the top end of the resilient member 323. In order to ensure that the top end of the die dot matrix electrode 33 can always maintain good contact with the bottom surface of the sheet blank 7 during the downward movement, and that the pressed die dot matrix electrode 33 can be re-moved upward and reset after the forming is completed, a resilient member 323 is arranged at the bottom end of the die dot matrix electrode 33. Specifically, the bottom surface of the female mold support member 321 is provided with a resilient member installation hole 3217 connected to the through hole 3223. The top of the resilient member installation hole 3217 is connected to the bottom of the through hole 3223 through a connecting hole 3216 located on the bottom surface of the insertion slot 3215. The connecting hole 3216 is coaxially arranged with the through hole 3223, and the aperture of the connecting hole 3216 is not less than the aperture of the through hole 3223, so that the bottom end of the female mold dot matrix electrode 33 can smoothly pass through the connecting hole 3216 and enter the resilient member installation hole 3217. The resilient member 323 is movably arranged in the resilient member installation hole 3217, and the bottom end of the female mold dot matrix electrode 33 is detachably plugged into the top end of the resilient member 323. A stopper 324 is fixedly connected in the resilient member mounting hole 3217, the bottom end of the resilient member 323 movably passes through the stopper 324, and a spring 325 is arranged between the resilient member 323 and the stopper 324. In this way, when the female mold dot matrix electrode 33 is pressed down by the bottom surface of the plate blank 7 and moves downward, the spring 325 is in a compressed state, and its reaction force on the resilient member 323 can make the top end of the female mold dot matrix electrode 33 always reliably contact with the bottom surface of the plate blank 7.

Since the axial depth of the resilient member mounting hole 3217 is larger than the lifting distance of the die dot matrix electrode 33, it is not convenient to fix and install the stopper 324 in the resilient member mounting hole 3217. Therefore, a mounting operation hole 3212 is provided on the side wall of the die support 321, which is connected with the resilient member mounting hole 3217 and located below the stopper 324. The outline size of the mounting operation hole 3212 is larger than the outline size of the stopper 324. The stopper 324 can be quickly sent into the resilient member mounting hole 3217 and positioned at its installation position through the mounting operation hole 3212. A first screw hole 3213 is provided on the side wall of the die support 321, which is located above the mounting operation hole 3212 and is connected with the resilient member mounting hole 3217. A threaded connection hole matched with the first screw hole 3213 is also provided on the side of the stopper 324, so that the stopper 324 can be fixedly connected to the die support 321 by screws.

The bottom end of the rebound member 323 is connected to the power supply end of the external power supply device through a power cord. In order to facilitate the arrangement and routing of the power cord, a threading groove 3211 is provided on the bottom surface of the die support member 321, so that the power cords led out from each die assembly unit 32 of each die annular assembly can pass through the threading groove 3211 in sequence to the outside of the groove.

The structure and working mode of the die center column 31 are the same as those of the die assembly unit 32, and will not be described in detail here.

At least one set of connecting columns 3224 is fixedly provided on the outer side surface of the forming die 322 in the die area of the outermost ring, and the two ends of the first connecting plate 5 are movably connected to the connecting columns 3224 on the two adjacent forming dies 322 in the die area of the outermost ring.

The outer surfaces of the two adjacent die assembly units 32 located in the outermost ring are connected and positioned by the first connecting plate 5, so as to cooperate with the annular embedding groove on the top of the substrate assembly 1 to limit the radial movement of each die assembly unit 32 during the stamping process (when the two adjacent die assembly units 32 are radially misaligned, the straight-line distance between the two corresponding points on their surfaces will increase accordingly, and the distance between the two ends of the first connecting plate 5 is fixed, which hinders the radial relative movement trend of the two adjacent die assembly units 32), so that the forming surface of the die assembly 3 remains intact. Specifically, at least one group (the upper and lower groups as shown in FIG. 13, and each group is one on the left and one on the right) of connecting columns 3224 are fixedly arranged on the outer side surface of the die area forming die 322 located in the outermost ring, and the two ends of the first connecting plate 5 are provided with circular holes, and the inner side surface is a concave arc surface matching the outer surface of the outermost layer of the die area forming die 322, and the two ends of the first connecting plate 5 are respectively movably connected with the connecting columns 3224 on the two adjacent die area forming dies 322 located in the outermost ring. After all the die assembly units 32 of the outermost ring are connected through the first connecting plate 5, the outermost layer of the die annular assembly can form a whole. By fitting the side walls between the inner and outer adjacent layers of the die annular assembly, the die annular assemblies can form a whole. In the process of stamping and drawing the plate blank 7 in cooperation with the punch assembly 4, the die forming surface formed by splicing the forming curved surfaces 3225 of the various die areas can also remain intact.

After the first connecting plate 5 is pulled outward, the outermost die ring assembly can be disassembled, and each die assembly unit 32 can be moved outward or upward and removed individually, and then the die ring assembly on the second outer side can also be disassembled. During use, if the die area forming curved surface 3225 of a die area forming mold 322 in a die ring assembly of the inner layer is damaged, or the power supply circuit of a die dot matrix electrode 33 fails, the die area forming mold 322 or the die assembly unit 32 corresponding to the die dot matrix electrode 33 can be vertically pulled out of the die assembly 3, the die area forming mold 322 is replaced or the power supply circuit of the die dot matrix electrode 33 is repaired, and then the new die assembly unit 32 is vertically inserted into its original position.

As shown in Figures 17 and 18, the punch assembly 4 includes a punch center column 41, a plurality of punch annular components coaxially and adjacently arranged on the outer side of the punch center column 41, each punch annular component is composed of a plurality of punch assembly units 42 adjacently spliced in sequence, a punch dot matrix electrode 43 is movably inserted in the punch center column 41 and each punch assembly unit 42, the outer surfaces of the two adjacent punch assembly units 42 located in the outermost ring are connected and positioned by a second connecting plate 6, the bottom surface of the punch assembly unit 42 in the same punch annular component constitutes a continuous annular curved surface, and each annular curved surface of different punch annular components and the bottom surface of the punch center column 41 constitute a continuous hemispherical convex arc surface. In this embodiment, the structure and assembly method of the punch assembly 4 are similar to those of the die assembly 3, and the structure and assembly method of the punch annular component and the die annular component 32 are also similar, which will not be repeated here.

As shown in FIG. 19 , the hanging plate assembly 8 includes a plurality of hanging plate units 81, a plurality of (correspondingly 4) hanging plate connectors 82 and a power hookup 83. The plurality of hanging plate units 81 are sequentially spliced to form a circular flat plate structure. Two adjacent hanging plate units 81 are connected by at least two hanging plate connectors 82. The hanging plate connectors 82 and the hanging plate units 81 are connected by screws. The power hookup 83 is fixedly connected to the center of the top surface of the circular flat plate structure by screws. In this embodiment, there are 4 hanging plate units 81, and two adjacent hanging plate units 81 are connected by two hanging plate connectors 82, that is, there are 8 hanging plate connectors 82 in total. By fixing the power hookup 83 with the external power output end, the male mold assembly 4 can be suspended directly above the female mold assembly 3, and then the male mold assembly 4 can be driven downward by the power output end to apply forming pressure to the plate blank 7, and the male mold assembly 4 can be driven to rise to achieve reset.

The hanging plate unit 81 is provided with screw connection holes corresponding to the punch assembly units of the punch assembly 3, and is fixedly connected to each punch assembly unit 42 by connecting screws set in the screw connection holes. A hanging ring is fixedly set on the top surface of each hanging plate connecting member 82. When a punch assembly unit 42 in the punch assembly 4 needs to be replaced, the punch assembly unit 42 can be separated from the punch ring assembly of the punch assembly 4 by loosening the corresponding connecting screws, and then pulled out downward, and then the new and identical punch assembly unit 42 is inserted upward into the original position, and then fixed by screw connection. If the punch assembly unit 42 that needs to be replaced is just below the hanger plate connector 82, it is hung with the hanging rings on the remaining 7 hanger plate connectors 82 other than the hanger plate connector 82 through the hanging rope, and the remaining 7 hanger plate connectors 82 are fixed and suspended, and then the hanger plate connector 82 is removed from the hanger plate unit 81, and the punch assembly unit 42 located below it can be disassembled and replaced. Since the two hanger plate unit components 81 connected to the hanger plate connector 82 are still connected and fixed to one hanger plate connector 82, the two hanger plate unit components 81 will not change their relative positions; if the punch assembly unit 42 that needs to be replaced is just below the power hanging component 83, the 8 hanger plate connectors 82 are suspended by the hanging rope so that the hanger plate unit component 81 is in a horizontal state. At this time, the power hanging component 83 can be removed from the hanger plate unit component 81, and then the punch assembly unit located below it can be disassembled and replaced.

The clamping assembly 2 is arranged in four groups and is evenly distributed in the circumferential direction of the die assembly 3. As shown in Fig. 20 and Fig. 21, the clamping assembly 2 comprises two support columns 21, a guide support plate 22 fixedly arranged at the top of the two support columns 21, a mobile support plate 23 slidably embedded in the top surface of the guide support plate 22, and a cylinder bracket 24 fixedly connected to the top surface of the mobile support plate 23. At least one positioning cylinder 25 is fixedly arranged on the bottom surface of the guide support plate 22, and the output rod end of the positioning cylinder 25 is connected to the side wall of the mobile support plate 23. At least one clamping cylinder 26 is fixedly arranged on the top surface of the cylinder bracket 24, and the output rod end of the clamping cylinder 26 is fixedly connected to a clamping electrode plate 27. In this embodiment, the bottom surface of the movable support plate 23 and the top surface of the guide support plate 22 are slidably connected through a dovetail groove structure. There are two positioning cylinders 25, which are symmetrically arranged on both sides of the bottom surface of the guide support plate 22. A first fixing plate is fixedly arranged at the bottom of the side of the movable support plate 23 away from the die assembly 3. The first fixing plate is fixedly connected to the output rod end of the positioning cylinder 25. The movable support plate 23 can be pushed close to or away from the die assembly 3 by the two positioning cylinders 25. Second fixing plates are fixedly arranged on both sides of the top surface of the cylinder bracket 24. There are two clamping cylinders 26, which are fixedly installed on the sides of the two second fixing plates. The clamping electrode plate 27 is located inside the cylinder bracket 24 and on the upper inner side of the movable support plate 23. The top surface of the clamping electrode plate 27 is fixedly connected to the output rod end of the clamping cylinder 26. The clamping cylinder 26 can drive the lifting movement of the clamping electrode plate 27.

In actual use, the clamping electrode plate 27 is connected to an output electrode (such as a negative electrode) of an external power supply device. In the non-working state, the positioning cylinder 25 makes the clamping electrode plate 27 located on the side away from the die assembly 3, so as to facilitate the placement operation of the plate blank 7 on the die assembly 3. When the plate blank 7 to be formed is placed on the top surface of the die assembly 3, the edge of the plate blank 7 is located on the top surface of the guide support plate 22, and then the positioning cylinder 25 drives the moving support plate 23 and the clamping cylinder 26 and the clamping electrode plate 27 thereon to move to the side close to the die assembly 3, so that the clamping electrode plate 27 is located just above the top edge of the plate blank 7, and then the clamping cylinder 26 drives the clamping electrode plate 27 to move downward, cooperating with the top surface of the guide support plate 22, and tightly clamping the edge of the plate blank 7.

Each punch dot matrix electrode 43 in the punch assembly 4 is connected to another output electrode (such as the positive electrode) of the external power supply device. During the downward movement of the punch assembly 4, stamping pressure is applied to the sheet blank 7 to cause the sheet blank 7 to be drawn and deformed. The punch dot matrix electrode 43 contacts the top surface of the sheet blank 7 from the inside to the outside, and within a preset time period after the punch dot matrix electrode 43 of each ring contacts the surface of the sheet blank 7, the current passing through the punch dot matrix electrode 43 gradually decreases. After the sheet blank 7 is stretched and deformed until its bottom surface is completely in contact with the hemispherical concave arc surface of the die assembly 3, the output electrode connected to the edge of the sheet blank 7 is switched to be connected to the die dot matrix electrode 33. The punch assembly 4 cooperates with the die assembly 3 to keep the semi-formed part for a preset time. Within the preset time period, the punch dot matrix electrode 43 cooperates with the die dot matrix electrode 33 to energize the semi-formed part for stress relaxation.

A zoned time-by-time electric-assisted forming process for a hemispherical shell, applied to the zoned time-by-time electric-assisted forming device for the hemispherical shell, is characterized by comprising the following steps:

S1, placing the plate blank 7 to be formed on the top surface of the die assembly 3, and clamping and fixing each edge of the plate blank 7 by each clamping assembly 2;

S2, the edge of the plate blank 7 is connected to an output electrode of the external power supply device through the clamping assembly 2, each male mold dot matrix electrode 43 is connected to another electrode of the external power supply device, and the external power supply device starts working;

S3, the punch power end drives the punch assembly 4 to move downward until the punch dot matrix electrode 43 in the punch center column 41 contacts the center of the top surface of the plate blank 7, and a preset current is passed into the plate blank 7 through the electrodes connected between the punch dot matrix electrode 43 and the edge of the plate blank 7, so that the plate blank 7 is energized and heated to a preset forming temperature;

S4, the punch assembly 4 continues to move downward, exerting a deformation force on the central part of the sheet blank 7, and the sheet blank 7 begins to be drawn and deformed. The current passing through the punch dot matrix electrode 43 in the punch central column 41 gradually decreases until the top surface of the sheet blank 7 contacts the punch dot matrix electrode 43 in the adjacent outer ring of the punch assembly unit 42, and a preset current is passed into the sheet blank 7 through the punch dot matrix electrode 43 of the ring and the electrode connected to the edge of the sheet blank 7 to compensate for the heat loss of the sheet blank 7, so that the sheet blank 7 is energized again and heated to the preset forming temperature;

S5, repeating the process of step S4 until the top surface of the plate blank 7 contacts the convex mold dot matrix electrode 43 in the outermost ring of the convex mold assembly unit 42 and the heat dissipation temperature compensation process of the plate blank 7 is completed;

S6, the male die assembly 4 continues to move downward, so that the plate blank 7 is drawn to the maximum position to form a semi-formed part. At this time, the bottom surface of the semi-formed part fits with the hemispherical concave arc surface of the female die assembly 3 and contacts with the end of each female die dot matrix electrode 33;

S7, the clamping assembly 2 releases the edge clamping part of the plate blank 7, disconnects the plate blank 7 from the output electrode of the external power supply device, and switches the output electrode to connect with the die dot matrix electrode 33, and energizes the semi-formed part through the cooperation of the male die dot matrix electrode 43 and the female die dot matrix electrode 33 to quickly heat up the semi-formed part, thereby completing stress relaxation of the semi-formed part in the pressure-maintaining state;

S8, the external power supply equipment stops working, the punch assembly 4 is driven by the punch power end to rise and reset, and after the semi-formed part is cooled down, the semi-formed part is taken out from the die assembly 3, and the top edge surplus of the semi-formed part is cut and polished to form a hemispherical shell.

The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims (10)

1. A zoned, time-by-time, electrically assisted forming device for hemispherical shell parts, characterized in that it comprises a base plate assembly (1), a die assembly (3) fixedly arranged on the top surface of the base plate assembly (1), a plurality of clamping assemblies (2) fixedly arranged on the top surface of the base plate assembly (1) and evenly distributed on the outside of the die assembly (3), a punch assembly (4) coaxially arranged just above the die assembly (3), and a hanging plate assembly (8) fixedly connected to the top of the punch assembly (4) and connected to a stamping power end; The die assembly (3) comprises a die central column (31), a plurality of die annular components coaxially and adjacently arranged on the outer side of the die central column (31), each die annular component being composed of a plurality of die assembly units (32) adjacently spliced in sequence, a die dot matrix electrode (33) being movably inserted in the die central column (31) and each die assembly unit (32), the outer surfaces of two adjacent die assembly units (32) located in the outermost ring being connected and positioned by a first connecting plate (5), the top surfaces of the die assembly units (32) in the same die annular component forming a continuous annular curved surface, and the annular curved surfaces of different die annular components and the top surface of the die central column (31) forming a continuous hemispherical concave arc surface; The punch assembly (4) comprises a punch center column (41), a plurality of punch annular components coaxially and adjacently arranged on the outer side of the punch center column (41), each punch annular component being composed of a plurality of punch assembly units (42) adjacently spliced in sequence, a punch dot matrix electrode (43) being movably inserted in the punch center column (41) and each punch assembly unit (42), the outer surfaces of two adjacent punch assembly units (42) located in the outermost ring being connected and positioned by a second connecting plate (6), the bottom surfaces of the punch assembly units (42) in the same punch annular component forming a continuous annular curved surface, and the annular curved surfaces of different punch annular components and the bottom surface of the punch center column (41) forming a continuous hemispherical convex arc surface; The plate blank (7) to be formed is fixed on the top surface of the die assembly (3) by the clamping assembly (2), the edge of the plate blank (7) is connected to an output electrode of an external power supply device, and the punch dot matrix electrode (43) is connected to another electrode of the external power supply device. During the downward movement of the punch assembly (4), a stamping pressure is applied to the plate blank (7) to cause the plate blank (7) to be drawn and deformed. The punch dot matrix electrode (43) contacts the top surface of the plate blank (7) from the inside to the outside, and the punch dot matrix electrodes (43) of each ring are in contact with the surface of the plate blank (7). Within a preset time period after the surface contact, the current in the male mold lattice electrode (43) gradually decreases, and after the plate blank (7) is stretched and deformed until its bottom surface is completely in contact with the hemispherical concave arc surface of the female mold component (3), the output electrode connected to the edge of the plate blank (7) is switched to be connected to the female mold lattice electrode (33), and the male mold component (4) and the female mold component (3) cooperate to keep the semi-formed part for a preset time. Within the preset time period, the male mold lattice electrode (43) and the female mold lattice electrode (33) cooperate to energize the semi-formed part for stress relaxation. 2. A zoned, time-by-time electrically assisted forming device for hemispherical shell parts according to claim 1, characterized in that: the die assembly unit (32) comprises a die support member (321) and a die area forming die (322), the top surface of the die support member (321) is provided with a plug-in groove (3215), the bottom surface of the die area forming die (322) is integrally provided with a plug-in block (3221), the plug-in block (3221) is plug-fitted with the plug-in groove (3215) and fastened by screw connection. 3. A zoned, time-by-time electrically assisted forming device for hemispherical shell parts according to claim 2, characterized in that: a vertically arranged through hole (3223) is provided in the forming die (322) of the die area, the die dot matrix electrode (33) is located in the through hole (3223), a resilient member mounting hole (3217) connected to the through hole (3223) is provided on the bottom surface of the die support member (321), a resilient member (323) is movably arranged in the resilient member mounting hole (3217), and the bottom end of the die dot matrix electrode (33) is detachably plugged into the top end of the resilient member (323). 4. A zoned, time-by-time electric-assisted forming device for hemispherical shell parts according to claim 3, characterized in that a stopper (324) is fixedly connected to the inside of the resilient member mounting hole (3217), the bottom end of the resilient member (323) movably passes through the stopper (324), and a spring (325) is provided between the resilient member (323) and the stopper (324). 5. A zoned, time-by-time electric-assisted forming device for hemispherical shell parts according to claim 4, characterized in that: a mounting operation hole (3212) connected to the spring-back mounting hole (3217) and located below the stopper (324) is provided on the side wall of the die support (321), and the mounting operation hole (3212) is larger than the stopper (324). 6. A zoned, time-by-time electrically assisted forming device for hemispherical shell parts according to any one of claims 2 to 5, characterized in that at least one set of connecting columns (3224) is fixedly arranged on the outer side surface of the forming die (322) in the die area of the outermost ring, and the two ends of the first connecting plate (5) are respectively movably connected to the connecting columns (3224) on the two adjacent die area forming dies (322) in the outermost ring. 7. A partitioned, time-by-time electric-assisted forming device for hemispherical shell parts according to any one of claims 1 to 5, characterized in that: the clamping assembly (2) includes two support columns (21), a guide support plate (22) fixedly arranged on the top of the two support columns (21), a movable support plate (23) slidably embedded in the top surface of the guide support plate (22), and a cylinder bracket (24) fixedly connected to the top surface of the movable support plate (23), at least one positioning cylinder (25) is fixedly arranged on the bottom surface of the guide support plate (22), the output rod end of the positioning cylinder (25) is connected to the side wall of the movable support plate (23), and at least one clamping cylinder (26) is fixedly arranged on the top surface of the cylinder bracket (24), and the output rod end of the clamping cylinder (26) is fixedly connected to a clamping electrode plate (27). 8. A partitioned, time-by-time electrically assisted forming device for hemispherical shell parts according to any one of claims 1 to 5, characterized in that: the substrate assembly (1) comprises a plurality of substrate units (11) and a plurality of substrate connectors (12), the plurality of substrate units (11) are sequentially spliced to form a square flat plate structure, and the top of the square flat plate structure is spliced to form a circular mounting groove, two adjacent substrate units (11) are connected by a substrate connector (12), and the substrate connector (12) and the substrate unit (11) are connected by screws. 9. A partitioned, time-by-time electrically assisted forming device for hemispherical shell parts according to any one of claims 1 to 5, characterized in that: the hanger plate assembly (8) comprises a plurality of hanger plate units (81), a plurality of hanger plate connectors (82) and a power hook-up member (83), the plurality of hanger plate units (81) are sequentially spliced to form a circular flat plate structure, two adjacent hanger plate units (81) are connected by at least two hanger plate connectors (82), the hanger plate connectors (82) and the hanger plate units (81) are connected by screws, and the power hook-up member (83) is fixedly connected to the center of the top surface of the circular flat plate structure by screws. 10. A zoned time-by-time electric-assisted forming process for a hemispherical shell, applied to the zoned time-by-time electric-assisted forming device for a hemispherical shell according to any one of claims 2 to 9, characterized in that it comprises the following steps: S1, placing a plate blank (7) to be formed on the top surface of the die assembly (3), and clamping and fixing the edges of the plate blank (7) by means of various clamping assemblies (2); S2, connecting the edge of the plate blank (7) to an output electrode of an external power supply device through the clamping assembly (2), connecting each male mold dot matrix electrode (43) to another electrode of the external power supply device, and starting the external power supply device; S3, the punch power end drives the punch assembly (4) to move downward until the punch dot matrix electrode (43) in the punch center column (41) contacts the center portion of the top surface of the plate blank (7), and a preset current is passed into the plate blank (7) through the electrodes connected to the punch dot matrix electrode (43) and the edge of the plate blank (7), so that the plate blank (7) is energized and heated to a preset forming temperature; S4, the punch assembly (4) continues to move downward, exerting a deformation force on the central part of the plate blank (7), causing the plate blank (7) to begin to be deformed by drawing, and the current passing through the punch lattice electrode (43) in the punch central column (41) gradually decreases until the top surface of the plate blank (7) contacts the punch lattice electrode (43) in the adjacent outer ring of the punch assembly unit (42), and a preset current is passed into the plate blank (7) through the punch lattice electrode (43) of the ring and the electrode connected to the edge of the plate blank (7), thereby compensating for the heat loss of the plate blank (7), so that the plate blank (7) is energized again and heated to a preset forming temperature; S5, repeating the process of step S4 until the top surface of the plate blank (7) contacts the punch matrix electrode (43) in the outermost ring of the punch assembly unit (42) and the heat dissipation temperature compensation process of the plate blank (7) is completed; S6, the male die assembly (4) continues to move downward, so that the plate blank (7) is drawn to the maximum position to form a semi-formed part, at which time the bottom surface of the semi-formed part fits with the hemispherical concave arc surface of the female die assembly (3) and contacts with the end of each female die dot matrix electrode (33); S7, the clamping assembly (2) releases the edge clamping portion of the plate blank (7), disconnects the plate blank (7) from the output electrode of the external power supply device, and switches the output electrode to be connected to the die dot matrix electrode (33), and energizes the semi-formed part through the cooperation of the male die dot matrix electrode (43) and the female die dot matrix electrode (33) to quickly heat the semi-formed part, thereby completing stress relaxation of the semi-formed part in a pressure-maintained state; S8, the external power supply device stops working, the punch power end drives the punch assembly (4) to rise and reset, and after the semi-formed part cools down, the semi-formed part is taken out from the die assembly (3), and the top edge of the semi-formed part is cut and polished to form a hemispherical shell.