Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a die structure for a plate rebound experiment capable of realizing switching of various stamping processes, which can realize the stamping rebound experiment on plates with different thicknesses by three processes of drawing, forming and flanging commonly used in actual engineering through one set of die structure, realize accurate acquisition of the rebound sizes of various types of plates and sufficiently know the rebound basic characteristics of plate stamping forming.
The specific technical scheme of the invention is as follows:
a die structure capable of realizing a plate springback experiment for switching various stamping processes is characterized in that the die structure is composed of an upper die and a lower die which are arranged up and down;
the upper die comprises an upper die base, an upper die pressure plate and a female die insert; the two die inserts are symmetrically fixed on the left side and the right side of the center of the lower end of the upper die base, the upper die pressure plate is arranged in the center of the upper die base, and the upper die pressure plate can extend into the space between the two die inserts when moving downwards;
the lower die comprises a blank holder, a male die bottom plate, a male die insert, a lower die insert and a male die; the two lower die insert blocks are symmetrically fixed at the upper end of the blank holder at the left side and the right side of the male die and are opposite to the female die insert block; the male die is fixed on the male die bottom plate below the blank holder, and the male die penetrates through the central hole of the blank holder and is fixedly connected with the male die insert; the male die insert and the upper die pressure plate are coaxially arranged, and the blank holder can be jacked up by a machine table and moves upwards relative to the male die base plate;
the die structure is used for flanging, drawing or forming and stamping the plate through the relative movement of the upper die pressing plate and the male die insert as well as the die insert and the lower die insert.
Further, the female die insert and the male die insert are respectively formed by overlapping and assembling a base insert and a supplementary insert, the base insert of the female die insert is in an insert shape with a maximum flanging forming angle required by an experiment, and the design angle of the supplementary insert of the female die insert is the difference between the maximum flanging forming angle and a target flanging forming angle; the base insert of the male die insert is in an insert shape with a minimum flanging forming angle required by an experiment, and the design angle of the supplementary insert of the male die insert is a target flanging forming angle; the supplementary inserts are multiple and respectively have different design angles, and the supplementary inserts and the matrix insert respectively form the female die insert and the male die insert with different flanging forming angles.
Furthermore, a plurality of front and back symmetrical grooves are formed in the side surface of the base insert, a gap exceeding the width of the plate is reserved between the front groove and the back groove, a plurality of convex blocks corresponding to the grooves are arranged on the opposite side of the supplementary insert and the base insert, and the female die insert and the male die insert are respectively embedded into the grooves through the convex blocks to form interference tight fit.
Further, the upper die further comprises four air cylinder devices, and the four air cylinder devices are respectively connected to the front side and the rear side of the outer portions of the left die insert and the right die insert and used for applying uniform lateral pressure to the die insert and adjusting a forming gap between the die insert and the male die insert.
Furthermore, the upper die further comprises a material pressing core and a pressure source device, the pressure source device is fixed on the upper die base, the material pressing core is fixed on the upper die pressing plate, and the pressure source device applies force to the upper die pressing plate through the material pressing core.
Further, the two pressure source devices are respectively arranged on the front side and the rear side above the material pressing core.
Furthermore, a guide plate is fixed on the upper die holder and used for guiding the up-and-down movement of the upper die and the lower die.
Furthermore, the left side and the right side of the blank holder are respectively fixed with a positioner for limiting the plate in the front-back direction and the left-right direction.
Furthermore, a plurality of stroke limiting blocks are arranged on the periphery of the blank holder and used for controlling the stamping stroke.
Furthermore, one side of the die insert is arranged on the upper die base through a back support piece.
The invention has the beneficial effects that:
the die structure has universality, is suitable for stamping of various stamping processes such as drawing, forming and flanging of plates with different materials and different thicknesses, breaks through the limitation that one set of die realizes one stamping process, realizes integration of various forming modes, reflects the rebound conditions of the plates under the process modes such as different edge pressing forces, different gaps, different flanging forming angles and the like, is convenient for deep research of the rebound mechanism of the plates, has simple structure and strong operability, improves the experimental efficiency, avoids resource waste caused by the need of manufacturing various stamping process dies, reduces the manufacturing cost, shortens the manufacturing period of the die, has centering property and high precision, and can be used for various experiments to share one set of die structure, improve the accuracy of the rebound experiment and meet the research on the rebound performance of the metal plates in a steel mill.
According to the invention, lateral force is provided by the air cylinder device to adjust the clearance between the convex-concave die, so that the switching of various stamping processes of different material thickness plates is realized, resources are fully utilized, the operability is strong, and the experimental efficiency is high. According to the invention, through the superposition assembly of the supplementary insert and the matrix insert, the resilience experiment requirements of different flanging forming angles are adapted, the manufacturing cost of the die is further saved, the modularization of the female die insert and the male die insert is realized, the supplementary insert can be rapidly replaced through the interference tight fit of the groove and the bump, the flanging forming angle is rapidly switched, the operation is simple and convenient, and the experiment efficiency is greatly improved.
Drawings
FIG. 1 is a schematic axial view of a die structure for a plate springback test capable of realizing switching of various stamping processes according to the present invention;
FIG. 2 is a front cross-sectional view of a die structure for a plate springback experiment, which can realize switching of various stamping processes according to the present invention;
FIG. 3 is a schematic view of the cylinder assembly of the present invention;
FIG. 4 is a front cross-sectional view of an upper mold in accordance with the present invention;
FIG. 5 is a bottom view of the upper mold of the present invention;
FIG. 6 is a lower mold structure diagram in accordance with the present invention;
FIG. 7 is a front sectional view of the lower mold of the present invention;
FIG. 8 is a schematic view of the die insert structure of the present invention;
FIG. 9 is a schematic view of the structure of the male die insert of the present invention;
FIG. 10 is a sectional view of the die structure in the initial state of the 0-degree flange according to the present invention;
FIG. 11 is a sectional view of the mold structure in a closed state of the 0 ° flange of the present invention;
FIG. 12 is a sectional view of the mold structure in the initial state of 3-degree flanging according to the invention;
FIG. 13 is a schematic view of the mold structure in a 3-degree flanged closed state according to the present invention;
FIG. 14 is a sectional view of the die structure in the initial state of 6-degree flanging according to the invention;
FIG. 15 is a schematic view of a mold structure in a 6-degree flanged closed state according to the present invention;
FIG. 16 is a sectional view of the die structure in an initial state of drawing according to the present invention;
FIG. 17 is a schematic view of the die configuration of the present invention in a drawn closed condition;
FIG. 18 is a sectional view of the mold structure in the initial state of forming according to the present invention;
FIG. 19 is a schematic view of the mold configuration in the closed state of the present invention.
Wherein: 1-an upper die holder, 2-a blank holder, 3-a punch bottom plate, 4-a connecting plate, 5-a guide plate, 6-a connecting template, 7-a material pressing core, 8-an upper die material pressing plate, 9-a die insert, 9.1-a left die matrix insert, 9.2-a right die matrix insert, 9.3-a left die complementary insert, 9.3.1-a left die 3-degree complementary insert, 9.3.2-a left die 0-degree complementary insert, 9.4-a right die complementary insert, 9.4.1-a right die 0-degree complementary insert, 9.4.2-a right die 3-degree complementary punch insert, 10-a punch insert, 10.1-a punch matrix insert and 10.2-a left die complementary insert; 10.2.1-3 degrees of supplementary insert of a left convex die, 10.2.2-6 degrees of supplementary insert of the left convex die, 10.3-right convex die supplementary insert, 10.3.1-6 degrees of supplementary insert of the right convex die, 10.3.2-3 degrees of supplementary insert of the right convex die, 11-lower die insert, 12-convex die, 13-cylinder device, 14-pressure source device, 15-pressure source device mounting plate, 16-back supporting piece, 17-positioner, 18-stroke limiting block, 19-groove, 20-lug and 21-plate.
Detailed Description
In order to make the technical solutions of the present application better understood by those skilled in the art, the present invention will be described in further detail below with reference to specific embodiments and accompanying drawings.
The terms of orientation such as up, down, left, right, front, and rear in the present specification are established based on the positional relationship shown in the drawings. The corresponding positional relationship may also vary depending on the drawings, and therefore, should not be construed as limiting the scope of protection.
In the present invention, the terms "mounted," "connected," "fixed," and the like are to be understood in a broad sense, and for example, may be fixedly connected, detachably connected, integrally connected, mechanically connected, electrically connected or capable of communicating with each other, directly connected, indirectly connected through an intermediate medium, or communicated between two components, or interacting between two components. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
The embodiment describes a die structure for a plate springback experiment capable of realizing switching of various stamping processes, the die structure is a set of bilateral symmetry dies capable of realizing switching of drawing, forming and flanging to perform the springback experiment, various stamping springback experiments such as drawing, forming and flanging of standard-size plates with different thicknesses and different materials can be switched, and the requirements of the stamping springback experiment performed on the plate are met.
The plate is subjected to one or more stamping processes such as drawing, forming, flanging and shaping in production, certain resilience is generated, particularly the resilience of the beam-like part is large, and the die structure is determined to be utilized to stamp the plate into a cap shape in order to fully reflect the resilience of the side wall and the flange area of the beam-like part. Through investigation on various vehicle types in the market, the height range of the side wall of a common beam part is known and counted, and a proper side wall height capable of fully reflecting resilience is selected by referring to the relevant size of the international standard conference NUMISHEET, so that the final stamping stroke of the die set is determined, and a proper plate size is selected.
The die structure comprises upper die and lower die, as shown in fig. 1, the upper die comprises an upper die base 1, the lower die comprises a blank holder 2 and a male die bottom plate 3, and when the die structure is idle, the upper die base 1 and the blank holder 2 are integrally placed through a connecting plate 4 through a connecting plate 6, the blank holder 2 and the male die bottom plate 3. When the die structure works, the connecting plate 4 and the connecting die plate 6 are detached, and the upper die base 1 and the blank holder 2 perform relative motion through the guide plate 5 on the upper die base 1 to complete the stamping of the plate.
As shown in fig. 2, the upper die further includes a pressing core 7, an upper die pressing plate 8, and a die insert 9. The two die inserts 9 are symmetrically fixed on the left side and the right side of the center of the lower end of the upper die base 1, the material pressing core 7 and the upper die material pressing plate 8 are sequentially arranged in the center of the upper die base 1 from top to bottom, and the material pressing core 7 and the upper die material pressing plate 8 can extend into a gap between the left die insert 9 and the right die insert 9 when moving downwards. The lower die further comprises a punch insert 10, a lower die insert 11 and a punch 12. The two lower die inserts 11 are symmetrically fixed at the upper end of the blank holder 2 at the left side and the right side of the male die 12 and are arranged opposite to the female die insert 9, the male die 12 is fixed on the male die base plate 3, the male die 12 penetrates through the central hole of the blank holder 2 and is fixedly connected with the male die insert 10, the male die insert 10 and the upper die pressure plate 8 are coaxially arranged, and the blank holder 2 can be jacked up by a mandril of a machine table and moves upwards relative to the male die base plate 3. The die structure realizes the drawing, forming and flanging of the plate through the relative movement of the upper die pressure plate 8 and the male die insert 10 as well as the female die insert 9 and the lower die insert 11.
In the embodiment, in order to meet the requirements of different thicknesses and different forming gaps of the plates, cylinder devices 13 are respectively connected to the front side and the rear side of the outer parts of the left die insert 9 and the right die insert 9, and the cylinder devices 13 are inversely arranged on the bottom of the upper die holder 1, as shown in fig. 3. Through the cylinder power size in the program control cylinder device 13 that sets up in advance, can be when the die structure during operation, exert even lateral pressure to die insert 9 to adjust the forming clearance between die insert 9 and the terrace die insert 10, thereby satisfy the panel of different thickness and carry out the punching press experiment requirement in multiple terrace die clearance, this convenient operation is simple, has reduced the panel punching press experiment degree of difficulty of kick-backing, has improved experimental efficiency.
In addition, as shown in fig. 4 and 5, in the upper mold of the present embodiment, 4 guide plates 5 are symmetrically fixed to the front and the back of the two ends of the upper mold base 1 through bolts, respectively, and the guide plates 5 can guide the up-and-down movement of the upper and the lower molds. The material pressing core 7 is fixedly connected with the upper die pressing plate 8 through a bolt, pressure source devices 14 are further respectively arranged on the front side and the rear side above the material pressing core 7, the pressure source devices 14 are fixed on the upper die base 1 through pressure source device mounting plates 15, and when the flanging process is carried out, the pressure source devices 14 apply force to the upper die pressing plate 8 through the material pressing core 7, so that the effect of pressing materials firstly is achieved. The two pressure source devices 14 of the present embodiment can make the plate uniformly stressed, and ensure the plate to be symmetrical in front and back after being formed. The two die inserts 9 are respectively installed and fixed on the upper die base 1 through bolts at the left side and the right side of the upper die pressure plate 8 to realize the pressure of the flange edge of the hat-shaped piece, one side of the die insert 9 is installed on the upper die base 1 through the back support piece 16, the back support piece 16 is used for limiting and positioning the die insert 9, the smooth installation of the die insert 9 can be ensured, and the tight matching and fixing of the die insert 9 and the upper die base 1 are realized. The die insert 9 realizes the adjustment of the clearance between the convex and concave dies through the cylinder device 13.
As shown in fig. 6 and 7, in the lower die of the present embodiment, the punch insert 10 may be fixed on the punch 12 by a bolt, the punch 12 is in an L-shaped structure, and the structure ensures that the punch insert 10 can be accurately limited, and meanwhile, the punch insert 10 cannot be deviated due to the action of force during operation. The punch bottom plate 3 is fixed below the punch 12 through threaded connection to support the punch 12, the punch bottom plate 3 enables the whole set of die to be placed on a machine table more stably, and the punch 12 is static all the time in work. The lower die insert 11 is fixed on the blank holder 2, and realizes the flange pressing of the plate together with the die insert 9 of the upper die. And the left side and the right side of the blank holder 2 are respectively fixed with a positioner 17 for limiting the plate in the front-back direction and the left-right direction, so that the plate is favorably fixed. A plurality of stroke limiting blocks 18 are arranged on the periphery of the blank holder 2, as shown in fig. 5, eight stroke limiting blocks 18 are provided in this embodiment, and are used for controlling the stamping stroke, and the corresponding stroke limiting blocks 18 need to be replaced for the plates with different thicknesses (namely, the thickness of the plate is reduced or increased, and the absolute value of the difference between the thickness of the original plate and the thickness of the existing plate is reduced or increased by the stroke limiting blocks 18 on the original basis), so that the gap between each insert when the mold is closed can be ensured to meet the thickness of the plate. In the embodiment, the convex die insert 10 is higher than the lower die insert 11, and the height difference is the height of the plate after stamping.
Through the research in earlier stage, understand and confirm the turn-ups shaping angle scope of automobile parts to carry out the turn-ups cutter design of mould structure, the die insert 9 and the terrace die insert 10 of this embodiment all adopt the interference tight-fitting principle to realize the turn-ups of different angles of panel, and greatly reduced need design and the cost of processing many sets of moulds, avoid the wasting of resources, reduced the mould processing and made total cycle.
The die insert 9 and the punch insert 10 of the present embodiment are both composed of a base insert and a complementary insert, the base insert of the die insert 9 is designed into an insert shape with a maximum flanging forming angle (6 ° in the present embodiment) required by an experiment, the base insert of the punch insert 10 is designed into an insert shape with a minimum flanging forming angle (0 ° in the present embodiment) required by an experiment, a plurality of front and rear symmetric grooves 19 are arranged on a side surface of the base insert for ensuring the assembly fastening with the complementary insert, and a gap exceeding the width of a plate is left between the front and rear grooves 19 to ensure the normal punching of the plate. The design angle of the supplementary insert of the female die insert 9 is the difference between the maximum flanging forming angle and the target flanging forming angle, and the design angle of the supplementary insert of the male die insert 10 is the target flanging forming angle. The complementary insert is provided with a plurality of projections 20 corresponding to the recesses 19 on the side opposite to the base insert. The female die insert 9 and the male die insert 10 form interference tight fit by embedding the convex block 20 into the groove 19, a plurality of supplementary inserts with different angles can be prepared by the supplementary inserts, and the flanging of the plate with different target flanging forming angles can be realized by replacing the supplementary inserts. The groove 19 and the bump 20 are respectively machined and manufactured with positive and negative tolerances, the two inserts are prevented from slipping through the friction action, the tight connection of the base insert and the complementary insert is realized, and the overall performance and the experimental precision of the inserts are ensured.
In the present embodiment, the details are described by taking 0 °, 3 °, and 6 ° cuffs as examples.
As shown in fig. 8, the left and right side die inserts 9 include a left die base insert 9.1, a right die base insert 9.2, a left die complementary insert 9.3, and a right die complementary insert 9.4, the left die base insert 9.1 and the right die base insert 9.2 are in the shape of inserts having inner sides of 6 ° respectively, and eight recesses 19 into which the protrusions 20 can be inserted are provided on the inner sides (i.e., the sides having the burring forming angle) respectively. The left female die supplementary insert 9.3 and the right female die supplementary insert 9.4 with angles are respectively connected and combined into the female die insert 9 with the corresponding flanging forming angle through the interference close fit by utilizing the convex block 20 and the left female die matrix insert 9.1 and the right female die matrix insert 9.2. The left die complementary insert 9.3 comprises a left die 3 ° complementary insert 9.3.1 and a left die 0 ° complementary insert 9.3.2, and the right die complementary insert 9.4 comprises a right die 0 ° complementary insert 9.4.1 and a right die 3 ° complementary insert 9.4.2.
When the angle is reduced to realize stamping at different flanging forming angles, the inner sides of the left female die matrix insert 9.1 and the right female die matrix insert 9.2 are respectively inserted into the left female die complementary insert 9.3 and the right female die complementary insert 9.4 through the grooves 19, and the design angle of the female die complementary insert is the difference between the maximum flanging forming angle and the target flanging forming angle. For example, the left die matrix insert 9.1 and the right die matrix insert 9.2 are respectively combined with the left die 3 ° complementary insert 9.3.1 and the right die 3 ° complementary insert 9.4.2 to form a 3 ° left die insert and a 3 ° right die insert, wherein the insert design angle of the left die 3 ° complementary insert 9.3.1 and the right die 3 ° complementary insert 9.4.2 is the difference between the experimental maximum flanging forming angle and 3 °, namely, is used for forming a 3 ° flanging forming angle. The left female die matrix insert 9.1 and the right female die matrix insert 9.2 are respectively combined with the left female die 0-degree supplementary insert 9.3.2 and the right female die 0-degree supplementary insert 9.4.1 to form a left female die insert and a right female die insert of 0 degrees, wherein the insert design angle of the left female die 0-degree supplementary insert 9.3.2 and the right female die 0-degree supplementary insert 9.4.1 is the difference between the experimental maximum flanging forming angle and 0 degrees, namely the insert design angle is used for forming the flanging forming angle of 0 degrees.
As shown in fig. 9, the punch insert 10 includes a punch base insert 10.1, a left punch complementary insert 10.2, and a right punch complementary insert 10.3, two sides of the punch base insert 10.1 are vertical (i.e. 0 °), and eight grooves 19 into which the protrusions 20 can be inserted are provided on two opposite side surfaces of the punch base insert 10.1, the grooves 19 on the front and rear sides are symmetrical with respect to the punch base insert 10.1, and four grooves 19 are provided on the front and rear sides of each side to ensure that the subsequent assembly is tight and the stress is uniform. One side of the left convex die supplementary insert 10.2 and the right convex die supplementary insert 10.3 opposite to the convex die base insert 10.1 is a vertical side, and the other side of the left convex die supplementary insert and the right convex die supplementary insert form a certain angle with the vertical side, wherein the designed angle is a corresponding flanging forming angle. The left punch complementary insert 10.2 comprises a left punch 3-degree complementary insert 10.2.1 and a left punch 6-degree complementary insert 10.2.2, and the right punch complementary insert 10.3 comprises a right punch 6-degree complementary insert 10.3.1 and a right punch 3-degree complementary insert 10.3.2. The machining, manufacturing and assembling principles of the female die insert 9 are consistent, when different flanging forming angles are punched by increasing the angles, the left male die supplementary insert 10.2 and the right male die supplementary insert 10.3 at corresponding angles are directly inserted into the left side and the right side of the male die base insert 10.1 through the grooves 19 by an interference tight fit method, and the male die insert 10 corresponding to the flanging forming angles is combined. If the punch substrate insert 10.1, the left punch 3-degree supplementary insert 10.2.1 and the right punch 3-degree supplementary insert 10.3.2 are combined into a punch insert with a flanging forming angle of 3 degrees, the punch substrate insert 10.1, the left punch 6-degree supplementary insert 10.2.2 and the right punch 6-degree supplementary insert 10.3.1 are combined into a punch insert with a flanging forming angle of 6 degrees.
In the flanging experiment, as shown in fig. 10, in the initial state of the 0 ° flanging, the left die base insert 9.1 and the right die base insert 9.2 in the die insert 9 are respectively embedded into the left die 0 ° complementary insert 9.3.2 and the right die 0 ° complementary insert 9.4.1, and the punch insert 10 is the punch base insert 10.1. The pressure source device 14 provides a pressing force for the upper die pressing plate 8 through the pressing core 7, the upper die base 1 moves downwards, the upper die pressing plate 8 firstly presses the plate 21 on the punch insert 10, then the upper die base 1 moves downwards continuously, and at the moment, the die insert 9 presses the plate 21 on the punch insert 10 and the lower die insert 11 to be flanged until the flanging is closed as shown in fig. 11.
When flanging experiments at different angles are carried out, a left die supplementary insert 9.3, a right die supplementary insert 9.4, a left punch supplementary insert 10.2 and a right punch supplementary insert 10.3 at corresponding target angles are respectively embedded in the left die base insert 9.1, the right die base insert 9.2 and the punch base insert 10.1 to form a die insert and a punch insert at a brand new angle, and then the operation steps of the 0-degree flanging experiment are carried out to realize flanging at different angles, such as the initial state and the closed state of a die with 3-degree flanging and 6-degree flanging in fig. 12, 13, 14 and 15.
When a drawing experiment is carried out, as shown in fig. 16, in an initial state of a die, the blank holder 2 is jacked up by a bench ejector rod, when the die works, the upper die holder 1 drives the upper die pressure plate 8 and the die insert 9 to move downwards, the plate 21 is pressed on the lower die insert 11, the blank holder 2 provides a blank holder force for the lower die insert 11, a pressure from bottom to top is applied to the plate 21, then the upper die holder 1 moves downwards along with the blank holder 2, the plate 21 is drawn through the die insert 10, and as shown in fig. 17, the die structure is in a closed state.
In the forming press test, as shown in fig. 18, the blank holder 2 was not lifted up unlike the drawing press in the initial state of the die. When the die works, the upper die holder 1 drives the upper die pressure plate 8 and the die insert 9 to move downwards, and the plate 21 is directly pressed on the male die insert 10 and the lower die insert 11 of the lower die, so that the forming experiment of the plate 21 is completed, as shown in fig. 19.
As can be seen from fig. 11, 13, 15, 17, and 19, the die structures in the closed state of the plate material 21 were consistent when the flanging, drawing, and forming experiments were performed. The drawing, forming and flanging experiment of the plate 21 is completed by one set of die structure, so that the accuracy of the whole experiment result is ensured, and the experiment error caused by different die machining precision is avoided.
While the principles of the invention have been described in detail in connection with the preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing embodiments are merely illustrative of exemplary implementations of the invention and are not limiting of the scope of the invention. The details of the embodiments are not to be interpreted as limiting the scope of the invention, and any obvious changes, such as equivalent alterations, simple substitutions and the like, based on the technical solution of the invention, can be interpreted without departing from the spirit and scope of the invention.