CN114101444A - Automobile rear longitudinal beam variable-strength hot stamping device and production process - Google Patents
Automobile rear longitudinal beam variable-strength hot stamping device and production process Download PDFInfo
- Publication number
- CN114101444A CN114101444A CN202111418132.2A CN202111418132A CN114101444A CN 114101444 A CN114101444 A CN 114101444A CN 202111418132 A CN202111418132 A CN 202111418132A CN 114101444 A CN114101444 A CN 114101444A
- Authority
- CN
- China
- Prior art keywords
- insert
- plate
- hot
- heat insulation
- area
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
- B21D22/02—Stamping using rigid devices or tools
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
- B21D22/02—Stamping using rigid devices or tools
- B21D22/022—Stamping using rigid devices or tools by heating the blank or stamping associated with heat treatment
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D37/00—Tools as parts of machines covered by this subclass
- B21D37/16—Heating or cooling
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D53/00—Making other particular articles
- B21D53/88—Making other particular articles other parts for vehicles, e.g. cowlings, mudguards
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Shaping Metal By Deep-Drawing, Or The Like (AREA)
Abstract
The invention provides a variable-strength hot stamping device for an automobile rear longitudinal beam and a production process for the automobile rear longitudinal beam, wherein the device comprises a plate heating system, a material transferring mechanism and a stamping system, the stamping system comprises a base and a stamping machine arranged near the base, and a punch of the stamping machine is positioned right above a die; the process comprises the following steps in sequence: preheating a plate, transferring the plate, hot stamping and forming, opening a die, taking a piece, and performing laser trimming. The method can accurately control the width of the variable-strength transition area of the rear longitudinal beam of the automobile, gradually change the tensile strength of the rear longitudinal beam of the automobile from 1420-1500 Mpa (hard area) to 910-950 Mpa (transition area) and then to 690-750 Mpa (soft area), thereby being beneficial to greatly improving the safety performance of the automobile, and the tensile strength of the transition area of the rear longitudinal beam of the automobile can be sharply reduced.
Description
Technical Field
The invention belongs to the technical field of automobile rear longitudinal beam production, and particularly relates to an automobile rear longitudinal beam strength-variable hot stamping device and an automobile rear longitudinal beam production process.
Background
With the development of automobile technology, requirements on vehicle safety, oil consumption and the like are higher and higher, the aim of reducing the weight of a vehicle body is met, and under the background, high-strength and ultrahigh-strength stamping parts are applied more and more. However, the press formability is gradually deteriorated with the increase in strength, and in order to solve this problem, a new hot forming press process is gradually developed. Before the hot forming stamping process is formed, the sheet materials are austenitized by heating, so that the formability of the sheet materials is improved; after punch forming, the strength of the formed part is improved through extremely rapid cooling and quenching.
In the practical use process, the higher the integral strength of the automobile parts is, the more favorable the safety of automobile collision is, but the key safety structural parts (such as the automobile rear longitudinal beam) need to have different strengths at different positions, and researches show that the automobile rear longitudinal beam combining the hard area, the transition area and the soft area can achieve the better collision energy absorption purpose and optimize the safety performance of the whole automobile. At present, in order to make the key safety structural member have multi-strength distribution performance, the process method for manufacturing the variable-strength member mainly comprises the following steps: a plate non-uniform heating method, a part welding method, a part local annealing method and a differential cooling method.
The existing document CN2011203934293 discloses a forming die for a variable-strength hot stamping part, which has the core points that a first female die block is provided with a cooling pipeline, a first male die block corresponding to the first female die block is also provided with a cooling pipeline, a second female die block is provided with a cooling pipeline, and a second male die block corresponding to the second female die block is not provided with a cooling pipeline; and cooling pipelines are not arranged on the third female die block and the fourth female die block, and cooling pipelines are not arranged on the corresponding third male die block and the fourth male die block. Although this type of die can achieve the strengthening of the workpiece by zone cooling, the greatest disadvantage is that: the transition zone of the produced workpiece is wider and has a width of 80-100mm, and the tensile strength of the same transition zone is sharply changed, and the tensile strength difference is up to 20-40%, taking the produced automobile B-pillar as an example, the tensile strength of the same transition zone (the area between 2 and 3 in figure 1) is between 800-. More importantly, the width of the transition zone in an ideal state should be controlled to be about 30mm, and the existing non-uniform heating method, part welding method, part local annealing method and differential cooling method for the plate material are difficult to control the width of the transition zone to be 40 +/-5 mm, and difficult to control the width of the transition zone to be 30 +/-5 mm.
Disclosure of Invention
The invention aims to provide a variable-strength hot stamping device for an automobile rear longitudinal beam and a production process for the automobile rear longitudinal beam, which are used for at least solving the technical problem that the width of a variable-strength transition area and the abrupt change of tensile strength of the automobile rear longitudinal beam are difficult to accurately control in the conventional method.
In order to achieve the above object, the present invention adopts the following technical solutions.
The utility model provides a longeron hot stamping device that becomes strong behind car, includes sheet material heating system, changes material mechanism and stamping system, and stamping system includes the base and sets up the punching machine near the base, and the drift of punching machine is located directly over the mould, and the mould includes mould and lower mould, its characterized in that: the lower die comprises a hot area insert and a cold area insert, a heat insulation plate is fixedly arranged between the hot area insert and the cold area insert, the upper edge of the heat insulation plate is flush with the upper edge of the lower die, the side edge of the heat insulation plate is flush with the side edge of the lower die, a gap is arranged between the heat insulation plate and the cold area insert, and the end face of the cold area insert close to the heat insulation plate is a solid vertical plane; the hot zone insert is internally provided with a pore canal transversely penetrating through the hot zone insert, the heat insulation plate is provided with a through hole, the inlet of the pore canal is externally connected with a pressurized hot flow gas supply system, the temperature of the pressurized hot flow gas is always controlled to be 390 plus 450 ℃, and the outlet of the pore canal is opposite to the through hole. The pressure of the hot flow gas with pressure is not less than 0.4MPa and not higher than 1 MPa.
In order to more accurately control the width of the variable-strength transition area of the automobile rear longitudinal beam, each point of the lower die molded surface is just positioned in the same circumferential zone by taking the through hole as the circle center on the same section, namely the molded surface farthest from the circle center is just positioned on the excircle of the circumferential zone, and the molded surface closest to the circle center is just positioned on the inner circle of the circumferential zone.
Preferably, the width of the gap is 12-18mm, and the thickness of the heat insulation plate is 8-12 mm.
In order to further accurately control the width of the variable-strength transition area of the automobile rear longitudinal beam, a heat insulation pipe is fixedly arranged on the inner wall of the pore channel.
In order to improve the stability of the variable-strength hot stamping device for the rear longitudinal beam of the automobile, facilitate installation and prolong the service life of the hot stamping device, the lower half part of the heat insulation plate is clamped in the gap, a high-temperature-resistant heat insulation sealing gasket is arranged between the lower half part of the heat insulation plate and the end face of the cold area insert close to the heat insulation plate, and the thickness of the upper half part of the heat insulation plate is 8-12 mm. High temperature resistance refers to the ability to withstand the upper limit temperature of the stamping process.
In order to further accurately control the width of the variable-strength transition region of the rear longitudinal beam of the automobile, a plurality of cooling water flow channels are arranged in the cold region insert close to the molded surface of the cold region insert, and the cooling water flow channels are externally connected with a circulating water system; a plurality of electric heating rods are arranged in the hot area insert close to the molded surface of the hot area insert, the electric heating rods are externally connected with a heating controller, an air channel is arranged in the hot area insert, and the air channel is externally connected with a compressed air system.
In order to improve the production efficiency of the automobile rear longitudinal beam, the material transferring mechanism comprises a mechanical clamping arm and a plurality of rows of rollers which are arranged in parallel and are divided into a material transferring area and a material stopping area, wherein the first row of rollers is positioned at a discharge hole of a plate heating system, a baffle is arranged beside the last row of rollers, wheel shafts of all the rollers in the material transferring area are connected with a driving system, and wheel shafts of all the rollers in the material stopping area are fixed shafts; a lifting mechanism is arranged below the material stopping area, a plurality of lifting plates of the lifting mechanism are respectively vertically arranged between two adjacent rows of rollers, and the top edges of the lifting plates are zigzag; the material transferring mechanism is connected with a central control system, when the heated plate runs from a discharge port of the plate heating system to a roller of a material stopping area, the central control system controls a wheel shaft to rotate so as to move the plate to the material stopping area, then the central control system controls the lifting plate to ascend so as to lift the plate and separate from the roller, the central control system controls the mechanical clamping arm to clamp the plate and transfer the plate to the lower die to be in place, and finally the lifting plate is controlled to reset.
In order to conveniently take the parts, the bottom of the movable insert at the tail end of the cold area is connected with the cylinder, and when the telescopic rod of the cylinder stretches, the movable insert moves synchronously along with the telescopic rod.
The production process of the automobile rear longitudinal beam is characterized in that the hot stamping device is adopted, and the production process sequentially comprises the following steps:
2, transferring materials, namely quickly transferring the heated plate materials to the lower die to be in place by using the material transferring mechanism, wherein the material transferring time is controlled within 5-8 seconds;
step, hot stamping and forming, wherein in the process, the temperature of the molded surface of the cold area insert of the lower die is always controlled to be 41-44 ℃, the temperature of the molded surface of the hot area insert of the lower die is always controlled to be 526-440 ℃, the hot flow gas with pressure flows through the pore channel and the through hole, and the temperature of the hot flow gas with pressure is always controlled to be 400-440 ℃;
and 4, opening the die, taking the workpiece and performing laser trimming.
As a preferred scheme, in the hot stamping forming process, the temperature of the molded surface of the hot area insert is controlled in an intermittent heating and cooling mode, when a temperature sensor in the hot area insert senses that the temperature reaches an upper limit temperature value, the power supply of the electric heating rod is controlled to be turned off, and a compressed air system is controlled to introduce compressed air into the air channel; when the temperature sensor in the hot zone insert senses that the temperature reaches the lower limit temperature value, the power supply of the electric heating rod is controlled to be started, and the compressed air system is controlled to be closed.
Has the advantages that: by sampling the scheme of the invention, on one hand, the width of the variable-strength transition region of the automobile rear longitudinal beam can be accurately controlled, and the width of the transition region can reach 30(0, +5) mm under the condition that the length of the soft region of the prepared automobile rear longitudinal beam (made of 22MnB5, with the length of 1713mm, the plate thickness of 1.6mm and the height of 318mm) is 235 mm; on the other hand, the tensile strength of the rear longitudinal beam of the automobile can be gradually changed from 1420-1500 Mpa (hard area) to 910-950 Mpa (transition area) and then to 690-750 Mpa (soft area), which is beneficial to greatly improving the safety performance of the automobile, so that the soft area is uniformly collapsed at the initial critical position of the collision, a good energy absorption effect is achieved, the soft area is prevented from being continuously collapsed after being collapsed to a certain position, and finally, the high strength performance is provided through the hard area, and the safety of passengers in a passenger area is ensured; moreover, the tensile strength of the obtained automobile rear side rail transition area can be sharply reduced.
Drawings
FIG. 1 is a partial schematic view of a variable-strength hot stamping device for a rear side member of an automobile in example 1;
FIG. 2 is a schematic lower die view of the automobile rear side member variable-strength hot stamping device in example 1;
FIG. 3 is a schematic view of the application (impingement) of hot pressurized fluid on the insert end face of example 1;
FIG. 4 is a partial schematic view of a material transferring mechanism of the variable-strength hot stamping device for the rear longitudinal beam of the automobile in the embodiment;
FIG. 5 is a schematic view of a lower die hot zone insert of the variable-strength hot stamping device for the rear longitudinal beam of the automobile in embodiment 1;
FIG. 6 is a schematic view of the application (impingement) of hot pressurized fluid to the insert end face of example 2;
FIG. 7 is a schematic view of an automobile rear side member produced in the embodiment;
FIG. 8 shows the structure conversion rate of the rear side member of the automobile after forming in the example.
Detailed Description
The following embodiments are merely provided to help understanding the principle of the present invention and the core idea thereof, and do not limit the scope of the present invention. It should be noted that modifications to the invention as described herein, which do not depart from the principles of the invention, are intended to be within the scope of the claims which follow.
Example 1
The variable-strength hot stamping device for the rear longitudinal beam of the automobile is explained first. Referring to fig. 1 to 4, the automobile rear longitudinal beam strength-variable hot stamping device comprises a plate heating system, a material transferring mechanism and a stamping system, wherein the stamping system comprises a base 1 and a stamping machine arranged near the base 1, a punch of the stamping machine is positioned right above a die, and the die comprises an upper die and a lower die 2. The lower die 2 comprises a hot area insert 21 and a cold area insert 22, the cold area insert 22 is formed by splicing six inserts, a heat insulation plate 23 is fixedly arranged between the hot area insert 21 and the cold area insert 22, the heat insulation plate 23 is fixed on the end surface of the hot area insert 21 through a fastener, the upper edge of the heat insulation plate 23 is flush with the upper edge of the lower die 2, the side edge of the heat insulation plate 23 is flush with the side edge of the lower die 2, namely the molded surface of the heat insulation plate 23 is consistent with the molded surface of the insert, a gap 24 is arranged between the heat insulation plate 23 and the cold area insert 22, and the end surface 39 of the cold area insert 22 close to the heat insulation plate 23 is a solid vertical plane; the hot zone insert 21 is provided with a duct 25 transversely penetrating the hot zone insert 21, the heat insulation plate 23 is provided with a through hole 26, the apertures of the duct 25 and the through hole 26 are 10mm, the inlet of the duct 25 is externally connected with a hot flow gas supply system under pressure through a gas pipe 35, the gas pipe 35 is provided with an electromagnetic valve 34 so as to control the on-off of the hot flow gas under pressure, the temperature of the hot flow gas under pressure is always controlled in a selectable temperature range of 390 and 450 ℃, and the outlet of the duct 25 is opposite to the through hole 26. The bottom of the movable insert 20 at the tail end of the cold area is connected with a cylinder, and when a telescopic rod of the cylinder stretches, the movable insert 20 moves synchronously along with the telescopic rod.
In the present embodiment, in the same cross section, taking the through hole 26 as the center of circle, each point of the molded surface 37 of the lower die 2 is exactly located on the same circumferential belt 38, and in fig. 3, the area between two circular broken lines represents the same circumferential belt 38; the width of the gap 24 is 15mm, and the thickness of the heat insulation plate 23 is 10 mm. In the invention, the molded surface refers to the contact area between the surface of the lower die 2 and the plate.
In this embodiment, referring to fig. 3, a heat insulation pipe 27 is fixedly disposed on the inner wall of the duct 25; a plurality of cooling water flow channels 28 are arranged in the cold area insert 22 close to the molded surface of the cold area insert 22, and the cooling water flow channels 28 are externally connected with a circulating water system; referring to fig. 1 and 2, a plurality of electric heating rods 29 are disposed in the hot zone insert 21 near the profile of the hot zone insert 21, the electric heating rods 29 are externally connected with a heating controller 30, an air passage 31 is disposed in the hot zone insert 21, and the air passage 31 is externally connected with a compressed air system. Each cold area insert is internally provided with a cooling water flow passage 28, the cooling water flow passages 28 between the adjacent cold area inserts are connected in series through a pipe section 33, and the inlet and the outlet of the cooling water flow passage 28 are connected with a circulating water system through a pipeline 32.
In this embodiment, referring to fig. 6, the material transferring mechanism includes a mechanical clamping arm, a plurality of rows of rollers 11 arranged in parallel, and is divided into a material transferring area 15 and a material stopping area 16, wherein the first row of rollers is located at a discharge port of a sheet heating system, a baffle 18 is arranged beside the last row of rollers, wheel shafts 17 of all the rollers 11 in the material transferring area 15 are used as movable shafts and connected with a driving system, and wheel shafts 17 of all the rollers 11 in the material stopping area 16 are used as fixed shafts; a lifting mechanism 13 is arranged below the material stopping area 16, a plurality of lifting plates 12 of the lifting mechanism 13 are respectively vertically arranged between two adjacent rows of rollers, and the top edges of the lifting plates 12 are zigzag; the material transferring mechanism is connected with a central control system, when the heated plate 14 runs from a discharge port of the plate heating system to a roller of the material stopping area 16, the central control system controls the wheel shaft 17 to rotate so as to move the plate 14 to the material stopping area 16, then the central control system controls the lifting plate 12 to ascend so as to lift the plate 14 and separate the plate from the roller 11, the central control system controls the mechanical clamping arm to clamp the plate 14 and transfer the plate onto the lower die 2 to be in place, and finally the lifting plate 12 is controlled to reset.
Next, a process for producing an automobile rear side member, which uses the variable-strength hot stamping apparatus for an automobile rear side member in this embodiment, will be described with reference to a produced automobile rear side member (material 22MnB5, total length 1713mm, sheet thickness 1.6mm, height 318mm, soft zone width 235mm, and structure thereof, see fig. 7). The process comprises the following steps in sequence:
step 3, performing hot stamping forming, wherein in the process, the temperature of circulating water is accurately controlled to ensure that the temperature of the molded surface of the cold area insert 22 of the lower die 2 is always controlled to be 41-44 ℃, the temperature of the molded surface of the hot area insert 21 of the lower die 2 is always controlled to be 526-;
in the step, the time for moving the upper die downwards is negligible (less than one second), the pressure maintaining time is controlled to be 15 seconds, namely, the upper die is kept still for 15 seconds after being pressed downwards during stamping, in the process, the cooling time of the cold area insert 22 to the workpiece is 15 seconds, the heat treatment time of the hot area insert 21 to the workpiece is 15 seconds, and the impact action time of hot-flow gas under pressure to the workpiece is also 15 seconds;
in the step, the temperature of cooling water in the cold area insert 22 is 20 ℃, and the flow of the cooling water is not less than 20L/min; the hot flow gas under pressure adopts high-temperature nitrogen with the pressure of 0.6Mpa, and in other embodiments, the hot flow gas under pressure can also adopt high-temperature steam;
in this step, the hot and pressurized gas flowing through the duct 25 and the through hole 26 impacts the end surface 39 of the cold block 22, the impacted part faces the through hole 26, then the hot and pressurized gas radiates in a circular manner and acts on the wall surface of the rear longitudinal beam of the automobile at the edge of the gap 24, and the radiation direction of the hot and pressurized gas is shown in the direction indicated by the arrow 36 in fig. 3; in this step, the temperature of the molded surface of the hot zone insert 21 is controlled in an intermittent heating and cooling manner, when the temperature sensor in the hot zone insert 21 senses that the temperature reaches an upper limit temperature value of 530 ℃, the power supply of the electric heating rod 29 is controlled to be turned off, and the compressed air system is controlled to introduce compressed air into the air channel 31; when the temperature sensor in the hot zone insert 21 senses that the temperature reaches the lower limit temperature value 526 ℃, controlling the power supply of the electric heating rod 29 to be started and the compressed air system to be closed, thereby controlling the temperature of the molded surface of the hot zone insert 21 to 526-530 ℃;
and 4, opening the die, taking the workpiece and performing laser trimming.
Example 2
A hot stamping device for strengthening a rear longitudinal beam of an automobile is disclosed by referring to embodiment 1 and combining with figures 5 and 6, and the main difference from embodiment 1 is that: the side wall of the heat insulation plate 23 is provided with a step 40, the lower half part (below the step 40) of the heat insulation plate 23 is clamped in the gap 24, a heat insulation sealing gasket is arranged between the lower half part of the heat insulation plate 23 and the end surface of the cold area insert 22 close to the heat insulation plate 23, the sum of the thicknesses of the pressed heat insulation sealing gasket and the lower half part of the heat insulation plate 23 is equal to the width of the gap 24, and the thickness of the upper half part (above the step 40) of the heat insulation plate 23 is 12 mm.
In this embodiment, the hot and pressurized gas flowing through the duct 25 and the through hole 26 impinges on the end surface 39 of the cold block 22, and the impinged portion faces the through hole 26, and then the hot and pressurized gas radiates in a fan-shaped manner and acts on the wall surface of the rear side member of the automobile at the edge of the slit 24, and the radiation direction of the hot and pressurized gas is shown by the arrow 36 in fig. 5.
Comparative example 1: a hot stamping device and a production process for the variable strength of a rear longitudinal beam of an automobile refer to an embodiment 1, and the difference between the embodiment 1 and the embodiment 1 is as follows: the lower die 2 is not provided with a gap 24, a heat insulation plate 23, a duct 25, a through hole 26, a pressurized hot flow gas supply system, an air channel 31 and a compressed air system externally connected with the air channel 31, and other process parameters related to the production process are the same as those in the embodiment 1. The die of this structure is substantially equivalent to the die for forming the hot stamped part with variable strength in CN 2011203934293.
Comparative example 2: a hot stamping device and a production process for the variable strength of a rear longitudinal beam of an automobile refer to an embodiment 1, and the difference between the embodiment 1 and the embodiment 1 is as follows: the lower die 2 is not provided with a heat insulation plate 23, a pore passage 25, a through hole 26, a pressurized hot flow gas supply system, an air channel 31 and a compressed air system externally connected with the air channel 31, and other process parameters related to the production process are the same as those in the embodiment 1.
Performance detection
Sampling the automobile rear longitudinal beams prepared in the embodiments to detect the tensile strength (the tensile strength detection method is a known technology in the field and is not described herein), wherein the detection parts comprise the inner side wall, the top wall and the outer side wall of each area of the automobile rear longitudinal beams, and the results are shown in table 1;
TABLE 1 tensile Strength of rear longeron of an automobile
Note: the inner side refers to the wall surface of the inner bending side of the automobile rear longitudinal beam, and the outer side refers to the wall surface of the outer convex side of the automobile rear longitudinal beam.
The method comprises the steps of sampling the rear longitudinal beam of the automobile prepared in each embodiment to detect the width of a transition zone, taking a gap facing part in the preparation process as a center, extending 90mm towards two sides respectively to prepare a metallographic sample, wherein the length of the sampling (single section) is 200 +/-5 mm, distinguishing martensite, bainite, ferrite and pearlite structures by adopting a common shallow (light) etching method for structural steel metallographic examination, slowly moving the metallographic sample by means of microscopic observation, marking the metallographic sample as a starting point when uneven black needle pieces appear at first and marking as an end point when uneven black needle pieces appear at last on the same experiment, and taking the width between the starting point and the end point as the width of the transition zone, wherein the result is shown in a table 2.
TABLE 1 automobile rear longitudinal transition zone Width
Note: after etching, microscopically uneven black needles are mainly coexistence of bainite and martensite, microscopically black short needles are mainly lower bainite.
The metallographic structure conversion rate of the automobile rear longitudinal beam formed in example 1 was measured, and the results are shown in fig. 8, in which: all the values in the upper graph represent the martensite conversion after molding, the middle three sets of values in the lower graph represent the bainite conversion after molding, and the left three sets of values in the lower graph represent the pearlite and ferrite conversion after molding.
Therefore, the width of the variable-strength transition region of the automobile rear longitudinal beam can be accurately controlled by the schemes of the embodiment 1 and the embodiment 2, and the width of the transition region can reach 31.4-32.6mm under the condition that the length of the prepared soft region of the automobile rear longitudinal beam is 235 mm; on the other hand, the tensile strength of the automobile rear longitudinal beam can be gradually changed from 1500Mpa (hard area) to 917-934 Mpa (transition area) and then to 715-720 Mpa (soft area), which is beneficial to greatly improving the safety performance of the automobile, so that the soft area is uniformly collapsed at the initial closed position of collision, a good energy absorption effect is achieved, the automobile rear longitudinal beam is prevented from being continuously collapsed after being collapsed to a certain position, and finally, the high-strength performance is provided through the hard area, and the safety of passengers in a passenger area is ensured; and the tensile strength of the transition region of the obtained automobile rear longitudinal beam can be controlled within 917-934 Mpa, and the tensile strength is reduced steeply.
Claims (10)
1. Longeron variable strength hot stamping device behind car, including sheet material heating system, commentaries on classics material mechanism and stamping system, stamping system includes base (1) and sets up the punching machine near base (1), and the drift of punching machine is located directly over the mould, and the mould includes mould and lower mould (2), its characterized in that: the lower die (2) comprises a hot area insert (21) and a cold area insert (22), a heat insulation plate (23) is fixedly arranged between the hot area insert (21) and the cold area insert (22), the upper edge of the heat insulation plate (23) is flush with the upper edge of the lower die (2), the side edge of the heat insulation plate (23) is flush with the side edge of the lower die (2), a gap (24) is arranged between the heat insulation plate (23) and the cold area insert (22), and the end surface of the cold area insert (22) close to the heat insulation plate (23) is a solid vertical plane; a pore passage (25) transversely penetrating through the hot zone insert (21) is arranged in the hot zone insert (21), a through hole (26) is arranged on the heat insulation plate (23), an inlet of the pore passage (25) is externally connected with a pressurized hot flow gas supply system, the temperature of the pressurized hot flow gas is always controlled to be 390 and 450 ℃, and an outlet of the pore passage (25) is opposite to the through hole (26).
2. The automobile rear longitudinal beam variable-strength hot stamping device according to claim 1, characterized in that: and in the same section, each point of the molded surface of the lower die (2) is just positioned in the same circumferential zone by taking the through hole (26) as the center of a circle.
3. The automobile rear longitudinal beam variable-strength hot stamping device according to claim 2, characterized in that: the width of the gap (24) is 12-18mm, and the thickness of the heat insulation plate (23) is 8-12 mm.
4. The automobile rear longitudinal beam variable-strength hot stamping device according to claim 3, wherein: and a heat insulation pipe (27) is fixedly arranged on the inner wall of the pore channel (25).
5. The automobile rear longitudinal beam variable-strength hot stamping device according to claim 3, wherein: the lower half part of the heat insulation plate (23) is clamped in the gap (24), a heat insulation sealing gasket is arranged between the lower half part of the heat insulation plate (23) and the end face of the cold area insert (22) close to the heat insulation plate (23), and the thickness of the upper half part of the heat insulation plate (23) is 8-12 mm.
6. The automobile rear side member variable-strength hot stamping device according to any one of claims 1 to 5, wherein: a plurality of cooling water flow channels (28) are arranged in the cold area insert (22) close to the molded surface of the cold area insert (22), and the cooling water flow channels (28) are externally connected with a circulating water system; a plurality of electric heating rods (29) are arranged in the hot zone insert (21) close to the molded surface of the hot zone insert (21), the electric heating rods (29) are externally connected with a heating controller (30), an air channel (31) is arranged in the hot zone insert (21), and the air channel (31) is externally connected with a compressed air system.
7. The automobile rear longitudinal beam variable-strength hot stamping device according to claim 6, wherein: the material transferring mechanism comprises a mechanical clamping arm and a plurality of rows of rollers which are arranged in parallel and is divided into a material transferring area and a material stopping area, wherein the first row of rollers is positioned at a discharge port of the plate heating system, a baffle is arranged beside the last row of rollers, and wheel shafts of all the rollers are connected with a driving system; a lifting mechanism is arranged below the material stopping area, a plurality of lifting plates of the lifting mechanism are respectively vertically arranged between two adjacent rows of rollers, and the top edges of the lifting plates are zigzag; the material transferring mechanism is connected with a central control system, when the heated plate runs from a discharge port of the plate heating system to a roller of a material stopping area, the central control system controls a wheel shaft to rotate so as to move the plate to the material stopping area, then the central control system controls the lifting plate to ascend so as to lift the plate and separate from the roller, the central control system controls the mechanical clamping arm to clamp the plate and transfer the plate to the lower die (2) to be in place, and finally the lifting plate is controlled to reset.
8. The automobile rear longitudinal beam variable-strength hot stamping device according to claim 7, wherein: the bottom of a movable insert (20) positioned at the tail end of the cold area is connected with a cylinder, and when a telescopic rod of the cylinder stretches, the movable insert (20) moves synchronously along with the telescopic rod.
9. A process for producing a rear longitudinal member for a motor vehicle, characterized in that use is made of a device according to any one of claims 1 to 8, comprising, in sequence:
step 1, preheating a marked 22MnB5 plate, transferring the preheated plate to a roller bottom heating furnace for step heating, wherein the mold feeding temperature is controlled to be 800 ℃ at 700-;
2, transferring materials, namely rapidly transferring the heated plate materials to the lower die (2) to be in place by using the material transferring mechanism, wherein the material transferring time is controlled within 5-8 seconds;
step 3, performing hot stamping forming, wherein in the process, the temperature of the molded surface of the cold area insert (22) of the lower die (2) is always controlled to be 41-44 ℃, the temperature of the molded surface of the hot area insert (21) of the lower die (2) is always controlled to be 526-440 ℃, the hot flow gas with pressure flows through the pore channel (25) and the through hole (26), and the temperature of the hot flow gas with pressure is always controlled to be 400-440 ℃;
and 4, opening the die, taking the workpiece and performing laser trimming.
10. The production process according to claim 9, characterized in that: in the hot stamping forming process, the temperature of the molded surface of the hot area insert (21) is controlled in an intermittent heating and cooling mode, when a temperature sensor in the hot area insert (21) senses that the temperature reaches an upper limit temperature value, the power supply of the electric heating rod (29) is controlled to be closed, and a compressed air system is controlled to introduce compressed air into the air channel (31); when a temperature sensor in the hot zone insert (21) senses that the temperature reaches a lower limit temperature value, the power supply of the electric heating rod (29) is controlled to be started, and the compressed air system is controlled to be closed.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202111418132.2A CN114101444B (en) | 2021-11-25 | 2021-11-25 | Automobile rear longitudinal beam variable-strength hot stamping device and production process |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202111418132.2A CN114101444B (en) | 2021-11-25 | 2021-11-25 | Automobile rear longitudinal beam variable-strength hot stamping device and production process |
Publications (2)
Publication Number | Publication Date |
---|---|
CN114101444A true CN114101444A (en) | 2022-03-01 |
CN114101444B CN114101444B (en) | 2022-07-19 |
Family
ID=80369607
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202111418132.2A Active CN114101444B (en) | 2021-11-25 | 2021-11-25 | Automobile rear longitudinal beam variable-strength hot stamping device and production process |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN114101444B (en) |
Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2927828A1 (en) * | 2008-02-26 | 2009-08-28 | Thyssenkrupp Sofedit Soc Par A | METHOD OF FORMING FROM FLAN IN SOFT MATERIAL WITH DIFFERENTIAL COOLING |
KR20110075732A (en) * | 2009-12-28 | 2011-07-06 | 현대하이스코 주식회사 | Hot press device for different strength in a product and manufacturing method using the same |
CN102304612A (en) * | 2011-09-20 | 2012-01-04 | 唐炳涛 | High-temperature splicing and quenching forming process and device of ultrahigh-strength steel |
CN102873213A (en) * | 2012-10-21 | 2013-01-16 | 吉林大学 | Ultrahigh-strength steel plate local quenching and hardening forming die |
CN103233109A (en) * | 2013-05-13 | 2013-08-07 | 武汉钢铁(集团)公司 | Control method and device for hot-forming plasticity distribution of high-strength steel |
KR20140113060A (en) * | 2013-03-15 | 2014-09-24 | 현대자동차주식회사 | Hot stamping mold |
CN204182791U (en) * | 2014-09-23 | 2015-03-04 | 宝山钢铁股份有限公司 | Hot stamping die |
CN205074407U (en) * | 2015-06-24 | 2016-03-09 | 武汉理工大学 | Forming die of local grow degree drop stamping piece |
CN106238584A (en) * | 2016-10-08 | 2016-12-21 | 齐齐哈尔大学 | Intensity adjustable diel |
KR20180019997A (en) * | 2016-08-17 | 2018-02-27 | 기아자동차주식회사 | Hot stamping device that pre cooles blank befor forming |
KR20180125222A (en) * | 2017-05-15 | 2018-11-23 | 주식회사 성우하이텍 | Hot stamping apparatus and method |
CN109590393A (en) * | 2017-10-03 | 2019-04-09 | 福特汽车公司 | For producing the cooling duct of the 3-D printing of the PHS part with tailored properties |
CN110893432A (en) * | 2018-09-12 | 2020-03-20 | 无锡朗贤轻量化科技股份有限公司 | Temperature control device for segmented reinforced die insert |
CN113134532A (en) * | 2020-01-17 | 2021-07-20 | 宝山钢铁股份有限公司 | Experimental device for be used for preparing gradient quenching tissue sheet material |
-
2021
- 2021-11-25 CN CN202111418132.2A patent/CN114101444B/en active Active
Patent Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2927828A1 (en) * | 2008-02-26 | 2009-08-28 | Thyssenkrupp Sofedit Soc Par A | METHOD OF FORMING FROM FLAN IN SOFT MATERIAL WITH DIFFERENTIAL COOLING |
KR20110075732A (en) * | 2009-12-28 | 2011-07-06 | 현대하이스코 주식회사 | Hot press device for different strength in a product and manufacturing method using the same |
CN102304612A (en) * | 2011-09-20 | 2012-01-04 | 唐炳涛 | High-temperature splicing and quenching forming process and device of ultrahigh-strength steel |
CN102873213A (en) * | 2012-10-21 | 2013-01-16 | 吉林大学 | Ultrahigh-strength steel plate local quenching and hardening forming die |
KR20140113060A (en) * | 2013-03-15 | 2014-09-24 | 현대자동차주식회사 | Hot stamping mold |
CN103233109A (en) * | 2013-05-13 | 2013-08-07 | 武汉钢铁(集团)公司 | Control method and device for hot-forming plasticity distribution of high-strength steel |
CN204182791U (en) * | 2014-09-23 | 2015-03-04 | 宝山钢铁股份有限公司 | Hot stamping die |
CN205074407U (en) * | 2015-06-24 | 2016-03-09 | 武汉理工大学 | Forming die of local grow degree drop stamping piece |
KR20180019997A (en) * | 2016-08-17 | 2018-02-27 | 기아자동차주식회사 | Hot stamping device that pre cooles blank befor forming |
CN106238584A (en) * | 2016-10-08 | 2016-12-21 | 齐齐哈尔大学 | Intensity adjustable diel |
KR20180125222A (en) * | 2017-05-15 | 2018-11-23 | 주식회사 성우하이텍 | Hot stamping apparatus and method |
CN109590393A (en) * | 2017-10-03 | 2019-04-09 | 福特汽车公司 | For producing the cooling duct of the 3-D printing of the PHS part with tailored properties |
CN110893432A (en) * | 2018-09-12 | 2020-03-20 | 无锡朗贤轻量化科技股份有限公司 | Temperature control device for segmented reinforced die insert |
CN113134532A (en) * | 2020-01-17 | 2021-07-20 | 宝山钢铁股份有限公司 | Experimental device for be used for preparing gradient quenching tissue sheet material |
Also Published As
Publication number | Publication date |
---|---|
CN114101444B (en) | 2022-07-19 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN102688944B (en) | Adjustable heating and cooling integrated hot forming die | |
KR101530367B1 (en) | Forming tool and method for hot forming and partially press hardening a workpiece made of sheet steel | |
US20160059295A1 (en) | Method and press for producing sheet metal parts that are hardened at least in regions | |
US10618094B2 (en) | Press systems and methods | |
CN101439382A (en) | Thermal punch forming technique and forming mold for super-strength steel | |
CN103233109B (en) | Control method and device for hot-forming plasticity distribution of high-strength steel | |
US10000823B2 (en) | Method and device for partially hardening sheet metal components | |
CN103402665A (en) | Method for bending sheet metal and product of sheet metal | |
KR20120093189A (en) | Method and device for producing a metal component | |
CN102039349A (en) | Method and thermal recasting assembly for producing a hardened, thermally recast workpiece | |
CN104087725B (en) | High-strength steel thermoforming area heating installation | |
KR20180014070A (en) | Noncontact cooling method of steel sheet and apparatus therefor | |
CN101664873A (en) | Laser-assisted roll bending forming device and method thereof | |
CN114101444B (en) | Automobile rear longitudinal beam variable-strength hot stamping device and production process | |
CN103386444B (en) | The direct-cooled technique of cooling fluid based on the hot-forming die of boron steel steel plate and device | |
CN207308748U (en) | The insert and hot forming tool of a kind of hot forming tool | |
CN103882323B (en) | MnCr alloying hot forming steel and production method thereof | |
CN211757698U (en) | Shape gradient control device of ultrahigh-strength steel | |
CN107413960A (en) | The insert and eccentric swage and hot forming tool of a kind of hot forming tool | |
CN203999688U (en) | High-strength steel thermoforming area heating installation | |
CN111266469B (en) | Device and method for riveting martensite steel plate without rivet | |
EP3778054B1 (en) | Intermediate heating station | |
KR20100026974A (en) | Press hardening method constituted continuous process, and apparatus | |
US20220258223A1 (en) | Press systems and methods | |
CN103350148B (en) | The direct-cooled technique of cooling fluid based on the hot-forming die of boron steel steel pipe and device |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PB01 | Publication | ||
PB01 | Publication | ||
SE01 | Entry into force of request for substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
GR01 | Patent grant | ||
GR01 | Patent grant |