CN113102598A - Liquid-filling pressing forming device and method for special-shaped section pipe fitting - Google Patents
Liquid-filling pressing forming device and method for special-shaped section pipe fitting Download PDFInfo
- Publication number
- CN113102598A CN113102598A CN202110380539.4A CN202110380539A CN113102598A CN 113102598 A CN113102598 A CN 113102598A CN 202110380539 A CN202110380539 A CN 202110380539A CN 113102598 A CN113102598 A CN 113102598A
- Authority
- CN
- China
- Prior art keywords
- pipe
- upper die
- lower die
- die frame
- section
- 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.)
- Pending
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
- B21D26/00—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces
- B21D26/02—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces by applying fluid pressure
- B21D26/033—Deforming tubular bodies
-
- 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
- B21D26/00—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces
- B21D26/02—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces by applying fluid pressure
- B21D26/033—Deforming tubular bodies
- B21D26/041—Means for controlling fluid parameters, e.g. pressure or temperature
-
- 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
- B21D26/00—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces
- B21D26/02—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces by applying fluid pressure
- B21D26/033—Deforming tubular bodies
- B21D26/045—Closing or sealing means
-
- 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
- B21D26/00—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces
- B21D26/02—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces by applying fluid pressure
- B21D26/033—Deforming tubular bodies
- B21D26/047—Mould construction
-
- 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
- B21D26/00—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces
- B21D26/02—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces by applying fluid pressure
- B21D26/033—Deforming tubular bodies
- B21D26/049—Deforming bodies having a closed end
Landscapes
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Shaping Metal By Deep-Drawing, Or The Like (AREA)
Abstract
The invention discloses a liquid filling and pressing forming device and a method for a special-shaped section pipe fitting, wherein the device comprises: the device comprises an upper template, an upper die frame, an upper die core, a lower template, a lower die frame, a lower die core, a supporting spring, a left sealing punch and a right sealing punch. The method comprises the following steps: determining the diameter and the wall thickness of an initial pipe; determining the supporting internal pressure required during liquid-filling press forming; placing an initial pipe on a lower die frame, and sealing two ends of the pipe by using a left sealing punch and a right sealing punch; filling fluid into the pipe until the pressure reaches the set internal support pressure; the mould descends, the upper mould frame and the lower mould frame are firstly closed, and the pipe is oppositely pressed and formed by the upper mould core and the lower mould core in a closed space formed by the upper mould frame and the lower mould frame; unloading the internal pressure, and opening the die to take out the part. The device and the method can effectively solve the problems that the undercut defect of the symmetrical parting surface occurs, the lower parting die with a sharp die is easy to damage and the like, can obviously improve the dimensional precision of the section fillet of the pipe fitting, and are suitable for the large-batch rapid production of high-precision liquid-filled compression molded pipe fittings.
Description
Technical Field
The invention relates to the technical field of pipe forming, in particular to a liquid filling and pressing forming device and method for a special-shaped section pipe fitting.
Background
The special-shaped section pipe fitting has the advantages of light weight, high strength, high rigidity and the like, and is widely applied to the fields of automobiles and aerospace in recent years. The internal high-pressure forming technology is an advanced manufacturing technology for a hollow part with an abnormal section, the integral forming axis of which is a two-dimensional or three-dimensional curve. However, when the pipe with the special-shaped cross section is formed by internal high pressure, high internal pressure (generally more than 100 MPa) is needed in the shaping stage to ensure that the fillet area is completely attached to the die, and the pipe with the dimensional accuracy meeting the requirement is obtained. For the high-strength steel pipe which is vigorously developed at present, when internal high-pressure forming is utilized, not only is the crack defect easily generated due to serious wall thickness reduction in a transition region, but also higher shaping pressure and forming equipment with larger tonnage are required.
For this purpose, a liquid-filled press forming technique is proposed, which is the biggest difference from the internal high-pressure forming technique in that: the inner pressure is generally lower than the yield inner pressure of the pipe during the liquid filling press forming, so that the pipe cannot be expanded and only plays a supporting role, and then the annular direction of the pipe is pressed by using a mould. In the process, the annular direction of the pipe is mainly subjected to bending deformation under the action of mould pressing, the internal pressure mainly inhibits the annular buckling or wrinkling of the pipe, the circumference of the section is basically not changed, and the section is changed from a circular shape to a special-shaped section. Liquid-filled press-forming molds are generally classified into open type and closed type. When the open die is used for carrying out liquid filling pressing forming on the pipe, pressing blocks in different directions are used for pressing respectively, and due to the fact that friction between the pipe and the die influences asymmetry in the pressing process, the sizes of round corners at different positions are different greatly after pressing is finished, and the design requirements cannot be met. In order to meet the precision requirements of different fillets, multiple times of pressing are generally needed, and the process is complex. Therefore, the pipe fitting obtained by the open die liquid-filling press forming has low round angle precision and is mainly used as a preform for internal high-pressure forming. Although the internal pressure required when the preform is formed by liquid-filled pressing is low, the rounding precision of the final pipe is ensured by the high pressure of the subsequent internal high-pressure forming shaping stage.
At present, a closed die is often adopted to carry out liquid filling press forming on the pipe fitting with the special-shaped section. For closed liquid-filled press forming dies, there are two main forms at present: the two-stage die is designed into a form similar to an internal high-pressure forming die in an up-and-down symmetrical split mode, and a form of a lower split mode. With the first form of the die, since the circumference of the cross section of the pipe is hardly changed or even a certain compression occurs during the pressing, the undercut phenomenon is particularly likely to occur at the parting line surface during the pressing. In general, in order to avoid undercut defects, a set of preforming mold needs to be added for preforming first, and then the preforming mold can be placed into a liquid-filled pressing mold for forming, but the process is increased, the production efficiency is reduced, and the mold cost is high. In the second type of die, in order to ensure the fillet precision, two sharp fillets (patent number: 201510999744.3) need to be machined on the lower die, however, the sharp fillets are difficult to machine, and are particularly easy to generate stress concentration during the pressing process, so that the sharp corners are damaged or the pipe fittings are accidentally damaged, and the second type of die is not suitable for mass production. In addition, another disadvantage of this form of mold is that the tube snaps back into the upper mold after forming, making removal particularly difficult.
Disclosure of Invention
The invention aims to provide a special-shaped section pipe filling press forming device and method, which are used for solving the problems that the existing closed type filling press forming die parting surface has undercut defects, a die with a sharp fillet is difficult to process and easy to damage, and cannot be applied to mass production, so that the pipe filling press forming process is simple, and the special-shaped section pipe meeting the requirement on fillet precision can be quickly obtained.
In order to achieve the purpose, the invention provides the following scheme:
the invention provides a liquid-filling pressing forming device for a special-shaped section pipe fitting, which comprises a pressing die and a sealing punch;
the pressing die comprises an upper die plate, an upper die frame, an upper die core, a lower die plate, a lower die frame, a lower die core and a supporting spring, wherein the upper die core is arranged at the bottom of the upper die plate, the upper die frame is arranged around the upper die core, the upper die frame is in sliding connection with the upper die core, the upper die frame is connected with the upper die plate through a limiting screw, the supporting spring is arranged between the upper die frame and the upper die plate, and the supporting spring enables a vertical distance to be reserved between the upper die frame and the upper die plate under the action of a spring force; the lower die core is arranged at the top of the lower template, the lower die frame is arranged around the lower die core, the lower die frame is connected with the lower die core in a sliding manner, the lower die frame is connected with the lower template through a limiting screw, a supporting spring is also arranged between the lower die frame and the lower template, and the supporting spring enables a vertical distance to be reserved between the lower die frame and the lower template under the action of a spring force; the upper die frame, the upper die core, the lower die frame and the lower die core form a die cavity together;
the sealing punch comprises a left sealing punch and a right sealing punch, the left sealing punch and the right sealing punch are respectively arranged on the left side and the right side of the pressing die, and a fluid inlet is formed in the left sealing punch or the right sealing punch.
Preferably, the support springs between the upper die frame and the upper die plate and between the lower die frame and the lower die plate are metal spiral die springs or nitrogen springs or polyurethane springs, the number of the support springs is 4-20, and the support springs are uniformly arranged on the upper die frame and the lower die frame.
Based on the special-shaped section pipe fitting liquid filling press forming device, the invention also provides a special-shaped section pipe fitting liquid filling press forming method, which comprises the following steps:
step S1: determining the diameter and the wall thickness of an initial pipe;
step S2: determining the required support internal pressure during the hydraulic pressing forming according to the diameter and the wall thickness of the initial pipe;
step S3: placing an initial pipe on a lower die frame, and simultaneously moving a left sealing punch and a right sealing punch in opposite directions until two ends of the pipe are completely sealed;
step S4: filling fluid into the pipe through a fluid inlet on the left sealing punch or the right sealing punch until the fluid pressure reaches the set support internal pressure;
step S5: the upper die frame and the upper die core move downwards simultaneously, the upper die frame and the lower die frame are closed at first, the pipe is formed by opposite pressing of the upper die core and the lower die core in a closed space formed by the upper die frame and the lower die frame, springs between the upper die frame and the upper die plate and between the lower die frame and the lower die plate are compressed during the period until the die is completely closed, and the forming is finished;
step S6: and unloading the internal pressure, opening the die, recovering the upper die frame and the upper die core as well as the lower die frame and the lower die core under the action of the supporting spring, retreating the left and right sealing punches, and taking out the formed pipe fitting.
Preferably, the target pipe section perimeter is equal to or less than the initial pipe section perimeter, that is, the initial pipe section perimeter is unchanged or is compressed to a certain extent during the liquid-filled press forming process, and the initial pipe diameter is determined as
Wherein d is0The diameter of the initial pipe is set, S is the section perimeter of the target pipe, delta is the change rate of the section perimeter, and delta is-3% -0%.
Preferably, the internal support pressure is less than or equal to the initial yield pressure of the pipe, the initial yield pressure being given by the formula
Determination of where psIs the initial yield internal pressure, t is the pipe wall thickness, sigmasThe initial yield strength of the pipe.
Preferably, the left sealing punch and the right sealing punch synchronously move downwards along with the pipe, the upper die frame and the lower die frame in the liquid filling and pressing process, and the left sealing punch and the right sealing punch move upwards along with the pipe, the upper die frame and the lower die frame to return to initial positions in the die opening process after forming.
Preferably, the pressing sequence among the upper mold core, the lower mold core and the pipe is adjusted by changing the elasticity and the length of the supporting springs between the upper mold base and the upper template and between the lower mold base and the lower template.
Preferably, when the circumference of the cross section of the pipe fitting changes by less than 3% along the axis, the initial pipe is a pipe with the same diameter, and the circumference of the section of the initial pipe is equal to the circumference of the maximum section of the pipe fitting; when the change of the circumference of the cross section of the pipe fitting along the axis is more than 3%, the initial pipe is a variable-diameter pipe, the circumference of the cross section of the initial pipe along the axis is equal to the circumference of the cross section of the pipe fitting at the corresponding position, and the initial yield pressure is calculated by the maximum diameter of the initial pipe.
Preferably, the tube is square or rectangular or trapezoidal or profiled in cross-section.
Preferably, the fluid is a liquid or a gas, the liquid is an emulsion or water, and the gas is air.
Compared with the prior art, the invention has the following beneficial technical effects:
the invention provides a liquid filling pressing forming device and a liquid filling pressing forming method for a special-shaped section pipe fitting, wherein an upper die and a lower die are respectively designed and processed into a die frame-die core structure, the upper die frame and the lower die frame are firstly closed in the die closing process, and the pipe fitting is pressed oppositely by the upper die core and the lower die core in a completely closed space, so that the problem of undercut defect at the die parting surface of the traditional pressing forming die can be effectively solved, and the problems that a sharp fillet in the lower die parting structure die is difficult to process, the stress is easy to concentrate and damage is difficult to take out are avoided. The size precision of the pipe fitting section fillet can be accurately controlled by respectively controlling the pressing amount of the upper mold core and the lower mold core. In addition, the invention has low pressure requirement and small equipment tonnage, can quickly realize the opening and closing action of the die and is very suitable for the mass production of the special-shaped section pipe fitting formed by hydraulic pressing.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.
FIG. 1 is a schematic structural view of a hydraulic press forming apparatus for a profiled cross-section pipe of the present invention;
FIG. 2 is a sectional view taken along line A-A of FIG. 1;
FIG. 3 is a flow chart of a method for forming a profiled cross-section pipe by liquid-filled press forming according to an embodiment of the present invention;
FIG. 4 is a schematic structural view of a profiled cross-section pipe at a point in the hydroforming process according to an embodiment of the present invention;
FIG. 5 is a schematic structural view of the special-shaped section pipe at the end of the liquid-filled press forming according to the embodiment of the invention;
in the figure: 1-upper template; 2-mounting a mould frame; 3, mounting a mold core; 4-a lower template; 5-lower die carrier; 6, lower mold core; 7-a support spring; 8-left sealing punch; 9-right sealing punch; 10-a fluid inlet; 11-pipe.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention aims to provide a liquid-filled press forming device and a liquid-filled press forming method for a special-shaped section pipe fitting, which aim to solve the problems in the prior art.
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.
The hydraulic-charging press forming device for the special-shaped section pipe fitting in the embodiment, as shown in fig. 1 and 2, comprises a pressing die and a sealing punch;
the pressing die comprises an upper die plate 1, an upper die frame 2, an upper die core 3, a lower die plate 4, a lower die frame 5, a lower die core 6 and a support spring 7, wherein the upper die core 3 is fixedly installed at the bottom of the upper die plate 1 through screws, the upper die frame 2 is arranged around the upper die core 3, the upper die frame 2 and the upper die core 3 are in clearance fit to realize sliding connection, the upper die frame 2 is connected with the upper die plate 1 through a limit screw, the threaded end of the limit screw is connected with the upper die plate 1, the other end of the limit screw is clamped with the upper die frame 2, the upper die frame 2 can slide up and down along a polished rod of the limit screw, the support spring 7 is installed between the upper die frame 2 and the upper die plate 1, and the support spring 7 enables a vertical distance to be reserved between the upper die frame 2 and the upper die; the lower die core 6 is arranged at the top of the lower die plate 4, the lower die carrier 5 is arranged around the lower die core 6, the lower die carrier 5 and the lower die core 6 are in clearance fit to realize sliding connection, the lower die carrier 5 is connected with the lower die plate 4 through a limit screw, a threaded end of the limit screw is connected with the lower die plate 4, the other end of the limit screw is clamped with the lower die carrier 5, the lower die carrier 5 can slide up and down along a polished rod of the limit screw, a support spring 7 is also arranged between the lower die carrier 5 and the lower die plate 4, and the support spring 7 enables a vertical distance to be reserved between the lower die carrier 5 and the lower die plate 4 under the action of a spring force; when the pressing mold is completely closed, the upper mold frame 2, the upper mold core 3, the lower mold frame 5 and the lower mold core 6 form a mold cavity together. The sealing punch comprises a left sealing punch 8 and a right sealing punch 9, the left sealing punch 8 and the right sealing punch 9 are respectively arranged on the left side and the right side of the pressing die, a fluid inlet 10 is formed in the left sealing punch 8 or the right sealing punch 9, and in the embodiment, the fluid inlet 10 is preferably formed in the right sealing punch 9.
In the embodiment, the supporting springs 7 between the upper die frame 2 and the upper die plate 1 and between the lower die frame 5 and the lower die plate 4 are metal spiral die springs or nitrogen springs or polyurethane springs, the number of the supporting springs 7 is 4-20, and the supporting springs 7 are uniformly arranged on the upper die frame 2 and the lower die frame 5.
As shown in fig. 3, on the basis of the special-shaped section pipe fluid-filled press forming device in the foregoing embodiment, the present embodiment further provides a special-shaped section pipe fluid-filled press forming method, including the following steps:
step S1: determining the diameter and the wall thickness of the initial pipe 11;
step S2: determining the required support internal pressure during the hydraulic pressing forming according to the diameter and the wall thickness of the initial pipe 11;
step S3: placing an initial pipe 11 on a lower die frame 5, and simultaneously moving a left sealing punch 8 and a right sealing punch 9 in opposite directions until two ends of the pipe 11 are completely sealed;
step S4: filling fluid into the pipe 11 through a fluid inlet 10 on the left sealing punch 8 or the right sealing punch 9 until the fluid pressure reaches the set supporting internal pressure;
step S5: the upper die frame 2 and the upper die core 3 move downwards simultaneously, the upper die frame 2 and the lower die frame 5 are closed firstly, the pipe 11 is oppositely pressed and formed by the upper die core 3 and the lower die core 6 in a closed space formed by the upper die frame 2 and the lower die frame 5, springs between the upper die frame 2 and the upper template 1 and between the lower die frame 5 and the lower template 4 are compressed until the die is completely closed, and the forming is finished;
step S6: and (3) unloading the internal pressure, opening the die, recovering the upper die frame 2 and the upper die core 3 as well as the lower die frame 5 and the lower die core 6 to the original positions under the action of the supporting spring 7, retreating the left and right sealing punches 9, and taking out the formed pipe fitting.
The following is a detailed discussion of the steps:
in step S1: determining the wall thickness of the initial pipe 11 according to the wall thickness size requirement of a target pipe; determining the diameter of the initial pipe 11 according to the section perimeter of a target pipe, wherein the section perimeter of the target pipe is equal to or less than the section perimeter of the initial pipe 11, that is, the section perimeter of the initial pipe 11 is not changed or is compressed to a certain extent in the hydraulic press forming process, and the diameter of the initial pipe 11 is determined as follows:
wherein d is0The diameter of an initial pipe 11 is adopted, S is the section perimeter of a target pipe fitting, delta is the change rate of the section perimeter, and delta is-3% -0%.
Further, when the circumference of the cross section of the pipe fitting varies by less than 3% along the axis, the initial pipe 11 is the pipe 11 with the same diameter, and the circumference of the cross section of the initial pipe 11 is equal to the circumference of the maximum cross section of the pipe fitting; when the circumference of the cross section of the pipe fitting changes by more than 3% along the axis, the initial pipe 11 is a variable-diameter pipe 11, and the circumference of the cross section of the initial pipe 11 along the axis is equal to the circumference of the cross section of the pipe fitting at the corresponding position.
Step S2: determining the required supporting internal pressure during the hydraulic press forming according to the diameter and the wall thickness of the initial pipe, wherein the supporting internal pressure is not higher than the initial yield pressure of the pipe, and the following conditions are divided:
when the initial pipe is equal-diameter pipe, the initial yield pressure is expressed by the formula
Is determined in which d0Is the initial pipe diameter, psIs the initial yield internal pressure, t is the pipe wall thickness, sigmasThe initial yield strength of the pipe.
When the initial pipe is a variable-diameter pipe, the initial yield pressure is expressed by the formula
Is determined in which d0maxIs the diameter of the initial tube at its largest cross-section.
Step S3: and placing the initial pipe on the lower die frame 5, and enabling the left sealing punch 8 and the right sealing punch 9 to simultaneously move towards the die direction in opposite directions until the two ends of the pipe are completely sealed.
When the initial pipe is placed on the lower die frame 5, the following conditions are divided:
when the diameter of the initial pipe is larger than the width of the mold cavity, the initial pipe needs to be flattened and preformed, and then the initial pipe is placed into the lower mold frame 5;
when the axial direction of the target pipe fitting is a two-dimensional or three-dimensional bending axis, the initial pipe fitting needs to be bent into a bent part consistent with a liquid-filled pressing forming die cavity by using a bending process so as to be smoothly placed into the lower die frame 5;
further, the left sealing punch 8, the right sealing punch 9 and the two ends of the pipe are sealed by Y-shaped or O-shaped sealing rings.
Step S4: filling fluid into the initial pipe through the fluid inlet 10 on the right sealing punch 9 until the fluid pressure reaches the set support internal pressure;
further, the fluid is a liquid, typically an emulsion or water, or a gas, typically air.
Step S5: the upper die plate 1 drives the upper die carrier 2 and the upper die core 3 to move downwards simultaneously, and the upper die carrier 2 and the lower die carrier 5 are firstly closed as shown in fig. 3; as the pressing continues, the support springs 7 between the upper die carrier 2 and the upper die plate 1, and between the lower die carrier 5 and the lower die plate 4 are compressed, and the pipe 11 is pressed and formed by the upper die core 3 and the lower die core 6 in the closed space formed by the upper die carrier 2 and the lower die carrier 5 in the opposite direction until the die is completely closed, and the forming is finished, as shown in fig. 4;
further, in the process of liquid filling and pressing, the left sealing punch 8 and the right sealing punch 9 move downwards synchronously with the pipe 11 and the lower die carrier 5; and in the process of opening the die after forming, the left sealing punch 8 and the right sealing punch 9 move upwards along with the pipe 11 and the lower die carrier 5 to return to the initial positions under the action of the reaction force of the supporting spring 7.
Furthermore, the pressing sequence among the upper mold core 3, the lower mold core 6 and the pipe 11 can be adjusted by changing the elasticity and the length of the supporting springs 7 between the upper mold base 2 and the upper mold plate 1 and between the lower mold base 5 and the lower mold plate 4.
Step S6: and (3) unloading the internal pressure, opening the die, recovering the upper die frame 2 and the upper die core 3 as well as the lower die frame 5 and the lower die core 6 to the original positions under the action of the supporting spring 7, and withdrawing the left sealing punch 9 and the right sealing punch 9 to take out the formed pipe fitting.
Further, the cross section of the pipe fitting is one or more of square, rectangle, trapezoid or special-shaped.
In the embodiment, the upper die frame 2 and the lower die frame 5 are firstly closed in the die closing and pressing process by respectively designing and processing the upper die frame and the lower die to form the die frame-die core structure, which is equivalent to that a pipe is formed by oppositely pressing the upper die core 3 and the lower die core 6 in the closed space formed by the upper die frame 2 and the lower die frame 5, so that the problem of undercut defect at the die parting surface of the upper die and the lower die of the traditional pressing and forming device is effectively solved, the problems that sharp fillets in the lower die parting structure die are difficult to process, the sharp fillets are easy to damage due to stress concentration and the difficulty in taking parts are effectively avoided, and the size precision of the pipe section fillets can be accurately controlled by controlling the pressing amount of the upper die core 3 and the lower. The invention has low pressure requirement and small equipment tonnage, can quickly realize the opening and closing action of the die and is very suitable for the mass production of the special-shaped section pipe fitting formed by hydraulic pressing.
The invention is further illustrated by the following specific examples:
taking the DD14 low carbon steel tube as an example, the cross section of the target pipe fitting is rectangular, and its dimensions are: the section width is 70mm, the height is 45mm, transition fillet radius, r is 6mm, and the wall thickness is t is 1.85 mm.
The method comprises the following steps: determining the wall thickness of the initial pipe according to the wall thickness size requirement of a target pipe, wherein the wall thickness requirement of the target pipe is 1.85mm, and selecting the pipe with the wall thickness of 1.85mm as a blank because the wall thickness of the pipe in the liquid filling and pressing process is not changed basically; and determining the diameter of the initial pipe according to the section perimeter of the target pipe, wherein the section perimeter of the target rectangular section pipe is 219.7 mm. The change rate of the section perimeter is delta-3% -0%, and then the initial pipe diameter d0The range of (A) is 69.93-72.10 mm, and the diameter of the initial pipe is finally determined to be 70 mm.
Step two: determining the required support internal pressure during the hydraulic pressing forming according to the diameter and the wall thickness of an initial pipe, wherein the diameter of the initial pipe is 70mm, and the wall thickness is t01.85mm, the initial yield strength of DD14 pipe is sigmas335 MPa. The initial yield pressure of the DD14 pipe is calculated to be ps17.7 MPa. Therefore, the internal pressure of the support at the time of the liquid-filled press forming is not higher than 17.7 MPa.
Step three: the DD14 tubular product is placed on the lower die frame, and the left sealing punch and the right sealing punch move towards the die simultaneously in opposite directions until the two ends of the DD14 tubular product are completely sealed.
Step four: and (3) filling the emulsion into the DD14 pipe through a fluid inlet on the right sealing punch until the liquid pressure reaches 15 MPa.
Step five: the upper die plate drives the upper die frame and the upper die core to move downwards simultaneously, and the upper die frame and the lower die frame are closed firstly; along with the continuous pressing, supporting springs between the upper die frame and the upper die plate and between the lower die frame and the lower die plate are compressed, and the pipe is pressed and formed by the upper die core and the lower die core in the opposite direction in a closed space formed by the upper die frame and the lower die frame until the die is completely closed, and the forming is finished; the liquid pressure inside the DD14 tube was kept constant throughout the press forming process.
Step six: and unloading the internal pressure, opening the die, recovering the upper die frame and the upper die core as well as the lower die frame and the lower die core under the action of the supporting spring, retreating the left and right sealing punches, and taking out the formed pipe fitting.
And repeating the second step and the fifth step, so that the DD14 pipe is subjected to liquid filling press forming under the action of unsupported internal pressure, 10MPa and 12MPa supported internal pressure respectively, and the pipe fitting with the rectangular section is obtained. According to the material object, when the internal pressure of the support is 10MPa, 12MPa and 15MPa, undercut defects are not generated at the parting surfaces of the upper die and the lower die, buckling or wrinkling defects are not generated in the annular direction, the radius of a fillet of the section is 5.8-6.0 mm, and the dimensional accuracy of the fillet meets the design requirement.
The fillet size uniformity of the DD14 rectangular section pipe fitting formed by the embodiment is improved by more than 40% compared with that of the conventional liquid-filled press forming device and method.
The principle and the implementation mode of the invention are explained by applying specific examples, and the description of the above examples is only used for helping understanding the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In summary, this summary should not be construed to limit the present invention.
Claims (10)
1. The utility model provides a dysmorphism cross section pipe fitting hydraulic fluid suppression forming device which characterized in that: comprises a pressing die and a sealing punch;
the pressing die comprises an upper die plate, an upper die frame, an upper die core, a lower die plate, a lower die frame, a lower die core and a supporting spring, wherein the upper die core is arranged at the bottom of the upper die plate, the upper die frame is arranged around the upper die core, the upper die frame is in sliding connection with the upper die core, the upper die frame is connected with the upper die plate through a limiting screw, the supporting spring is arranged between the upper die frame and the upper die plate, and the supporting spring enables a vertical distance to be reserved between the upper die frame and the upper die plate under the action of a spring force; the lower die core is arranged at the top of the lower template, the lower die frame is arranged around the lower die core, the lower die frame is connected with the lower die core in a sliding manner, the lower die frame is connected with the lower template through a limiting screw, a supporting spring is also arranged between the lower die frame and the lower template, and the supporting spring enables a vertical distance to be reserved between the lower die frame and the lower template under the action of a spring force; the upper die frame, the upper die core, the lower die frame and the lower die core form a die cavity together;
the sealing punch comprises a left sealing punch and a right sealing punch, the left sealing punch and the right sealing punch are respectively arranged on the left side and the right side of the pressing die, and a fluid inlet is formed in the left sealing punch or the right sealing punch.
2. The liquid-filled press forming device for profiled cross-section pipes according to claim 1, wherein: the support springs between the upper die frame and the upper die plate and between the lower die frame and the lower die plate are metal spiral die springs or nitrogen springs or polyurethane springs, the number of the support springs is 4-20, and the support springs are uniformly arranged on the upper die frame and the lower die frame.
3. A special-shaped section pipe hydraulic-charging press-forming method by using the special-shaped section pipe hydraulic-charging press-forming device of claim 1, characterized by comprising the following steps:
step S1: determining the diameter and the wall thickness of an initial pipe;
step S2: determining the required support internal pressure during the hydraulic pressing forming according to the diameter and the wall thickness of the initial pipe;
step S3: placing an initial pipe on a lower die frame, and simultaneously moving a left sealing punch and a right sealing punch in opposite directions until two ends of the pipe are completely sealed;
step S4: filling fluid into the pipe through a fluid inlet on the left sealing punch or the right sealing punch until the fluid pressure reaches the set support internal pressure;
step S5: the upper die frame and the upper die core move downwards simultaneously, the upper die frame and the lower die frame are closed at first, the pipe is formed by opposite pressing of the upper die core and the lower die core in a closed space formed by the upper die frame and the lower die frame, springs between the upper die frame and the upper die plate and between the lower die frame and the lower die plate are compressed during the period until the die is completely closed, and the forming is finished;
step S6: and unloading the internal pressure, opening the die, recovering the upper die frame and the upper die core as well as the lower die frame and the lower die core under the action of the supporting spring, retreating the left and right sealing punches, and taking out the formed pipe fitting.
4. The liquid-filled press forming method for profiled cross-section pipes according to claim 3, wherein: the section perimeter of the target pipe fitting is equal to or less than the section perimeter of the initial pipe, namely the section perimeter of the initial pipe is not changed or is compressed to a certain extent in the process of liquid-filled press forming, and the diameter of the initial pipe is determined as
Wherein d is0The diameter of the initial pipe is set, S is the section perimeter of the target pipe, delta is the change rate of the section perimeter, and delta is-3% -0%.
5. The liquid-filled press forming method for profiled cross-section pipes according to claim 3, wherein: the internal supporting pressure is less than or equal to the initial yield pressure of the pipe, and the initial yield pressure is expressed by the formula
Determination of where psIs the initial yield internal pressure, t is the pipe wall thickness, sigmasThe initial yield strength of the pipe.
6. The liquid-filled press forming method for profiled cross-section pipes according to claim 3, wherein: and the left sealing punch and the right sealing punch synchronously move downwards along with the pipe, the upper die frame and the lower die frame in the liquid filling and pressing process, and the left sealing punch and the right sealing punch move upwards along with the pipe, the upper die frame and the lower die frame to return to initial positions in the die opening process after the forming is finished.
7. The liquid-filled press forming method for profiled cross-section pipes according to claim 3, wherein: and the pressing sequence among the upper mold core, the lower mold core and the pipe is adjusted by changing the elasticity and the length of the supporting springs between the upper mold base and the upper template and between the lower mold base and the lower template.
8. The liquid-filled press forming method for profiled cross-section pipes according to claim 3, wherein: when the change of the circumference of the cross section of the pipe fitting along the axis is less than 3%, the initial pipe is a pipe with the same diameter, and the circumference of the cross section of the initial pipe is equal to the circumference of the maximum cross section of the pipe fitting; when the change of the circumference of the cross section of the pipe fitting along the axis is more than 3%, the initial pipe is a variable-diameter pipe, the circumference of the cross section of the initial pipe along the axis is equal to the circumference of the cross section of the pipe fitting at the corresponding position, and the initial yield pressure is calculated by the maximum diameter of the initial pipe.
9. The liquid-filled press forming method for profiled cross-section pipes according to claim 3, wherein: the cross section of the pipe fitting is square or rectangular or trapezoidal or special-shaped.
10. The liquid-filled press forming method for profiled cross-section pipes according to claim 3, wherein: the fluid is liquid or gas, the liquid is emulsion or water, and the gas is air.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110380539.4A CN113102598A (en) | 2021-04-09 | 2021-04-09 | Liquid-filling pressing forming device and method for special-shaped section pipe fitting |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110380539.4A CN113102598A (en) | 2021-04-09 | 2021-04-09 | Liquid-filling pressing forming device and method for special-shaped section pipe fitting |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113102598A true CN113102598A (en) | 2021-07-13 |
Family
ID=76714916
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110380539.4A Pending CN113102598A (en) | 2021-04-09 | 2021-04-09 | Liquid-filling pressing forming device and method for special-shaped section pipe fitting |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113102598A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113878016A (en) * | 2021-09-28 | 2022-01-04 | 上海孚庭科技有限公司 | Forming method of pipe fitting with complex section |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11333526A (en) * | 1998-05-25 | 1999-12-07 | Nissan Motor Co Ltd | Manufacture of cylindrical member for vehicle body structure |
| JP2005152920A (en) * | 2003-11-21 | 2005-06-16 | Kobe Steel Ltd | Flanged tubular member and method for manufacturing the same |
| CN102527812A (en) * | 2011-12-26 | 2012-07-04 | 北京航空航天大学 | Combined mould for pipe free bulging |
| CN105562516A (en) * | 2016-03-15 | 2016-05-11 | 哈尔滨工业大学 | Charging pressing forming method for variable-cross-section special-shaped pipe |
| CN106216481A (en) * | 2016-09-14 | 2016-12-14 | 哈尔滨工业大学 | A kind of big section difference odd-shaped cross section pipe fitting swelling pressure combined shaping method |
| CN109174970A (en) * | 2018-08-22 | 2019-01-11 | 哈尔滨工业大学 | A kind of roll-forming method and device of the metal abnormity variable cross-section tubing based on hydroforming |
| CN110883179A (en) * | 2019-11-28 | 2020-03-17 | 哈尔滨工大海卓智能成形科技有限公司 | Hydraulic forming part rebound control method and system based on liquid volume loading |
| CN110935779A (en) * | 2019-12-13 | 2020-03-31 | 哈尔滨工大海卓智能成形科技有限公司 | Pipe liquid-filling multidirectional extrusion forming device and method |
| US20200346271A1 (en) * | 2018-11-19 | 2020-11-05 | Dalian University Of Technology | Method for pressure forming of aluminum alloy special-shaped tubular component by using ultra-low temperature medium |
| CN112024692A (en) * | 2020-08-19 | 2020-12-04 | 哈尔滨工业大学 | Ultra-low pressure liquid-filling forming system and method for special-shaped component |
-
2021
- 2021-04-09 CN CN202110380539.4A patent/CN113102598A/en active Pending
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11333526A (en) * | 1998-05-25 | 1999-12-07 | Nissan Motor Co Ltd | Manufacture of cylindrical member for vehicle body structure |
| JP2005152920A (en) * | 2003-11-21 | 2005-06-16 | Kobe Steel Ltd | Flanged tubular member and method for manufacturing the same |
| CN102527812A (en) * | 2011-12-26 | 2012-07-04 | 北京航空航天大学 | Combined mould for pipe free bulging |
| CN105562516A (en) * | 2016-03-15 | 2016-05-11 | 哈尔滨工业大学 | Charging pressing forming method for variable-cross-section special-shaped pipe |
| CN106216481A (en) * | 2016-09-14 | 2016-12-14 | 哈尔滨工业大学 | A kind of big section difference odd-shaped cross section pipe fitting swelling pressure combined shaping method |
| CN109174970A (en) * | 2018-08-22 | 2019-01-11 | 哈尔滨工业大学 | A kind of roll-forming method and device of the metal abnormity variable cross-section tubing based on hydroforming |
| US20200346271A1 (en) * | 2018-11-19 | 2020-11-05 | Dalian University Of Technology | Method for pressure forming of aluminum alloy special-shaped tubular component by using ultra-low temperature medium |
| CN110883179A (en) * | 2019-11-28 | 2020-03-17 | 哈尔滨工大海卓智能成形科技有限公司 | Hydraulic forming part rebound control method and system based on liquid volume loading |
| CN110935779A (en) * | 2019-12-13 | 2020-03-31 | 哈尔滨工大海卓智能成形科技有限公司 | Pipe liquid-filling multidirectional extrusion forming device and method |
| CN112024692A (en) * | 2020-08-19 | 2020-12-04 | 哈尔滨工业大学 | Ultra-low pressure liquid-filling forming system and method for special-shaped component |
Non-Patent Citations (3)
| Title |
|---|
| 王碧: "某车架纵梁内高压成形工艺数值仿真分析研究", 《中国优秀博硕士学位论文全文数据库(硕士)工程科技Ⅱ辑》 * |
| 王碧: "某车架纵梁内高压成形工艺数值仿真分析研究", 《中国优秀博硕士学位论文全文数据库(硕士)工程科技Ⅱ辑》, no. 8, 15 August 2015 (2015-08-15), pages 13 - 35 * |
| 黄晓峰: "管状变截面汽车扭力梁内高压成形工艺", 《精密成形工程》, vol. 10, no. 2, 31 March 2018 (2018-03-31), pages 111 - 116 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113878016A (en) * | 2021-09-28 | 2022-01-04 | 上海孚庭科技有限公司 | Forming method of pipe fitting with complex section |
| CN113878016B (en) * | 2021-09-28 | 2024-03-08 | 上海孚庭科技有限公司 | Forming method of pipe fitting with complex section |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105562516A (en) | Charging pressing forming method for variable-cross-section special-shaped pipe | |
| CN101497096B (en) | Device for processing reducer pipe fitting with big section difference and method for shaping the same | |
| CN105598265A (en) | Overall forming method of small-relative-bending-radius and large-diameter-thickness-ratio thin-walled bent pipe fitting | |
| CN110434216B (en) | Integral liquid filling forming method for large annular lip piece | |
| LANG et al. | Pre-bulging effect during sheet hydroforming process of aluminum alloy box with unequal height and flat bottom | |
| CN105537360A (en) | Forward-backward drawing and forming method for metal plate soft mould | |
| CN113182388B (en) | Thin-wall multi-cavity member shape correction die and method based on compression deformation | |
| CN103212635B (en) | Car transmission synchronizer gear ring fine blanking and deep drawing combined forming process and mold | |
| CN113102598A (en) | Liquid-filling pressing forming device and method for special-shaped section pipe fitting | |
| CN113020391A (en) | Ultrahigh-pressure forming method and device for high-temperature alloy fluid medium | |
| CN110834047B (en) | Internal pressure forming method for large-size thin-wall pipe fitting gas-liquid mixed fluid | |
| CN104259308B (en) | A kind of pipe end is without the tool heads of the progressive rolled forming of modulus control and method | |
| CN102921791A (en) | Section-variable hollow component forming device and method | |
| CN202667454U (en) | Mechanical integrated forming mould for automobile axle housing | |
| CN107649586B (en) | It is a kind of for circular cone involucrum shaping dies and its manufacturing process of circular cone involucrum | |
| CN109127851A (en) | A kind of manufacturing process based on hydraulic aluminium alloy sheet part | |
| CN104043697B (en) | U-bolt curving apparatus | |
| CN103286151A (en) | Preparation device and method for manufacturing inside and/or outside thickened aluminum alloy pipes with variable cross sections | |
| CN103691794A (en) | Self-pressurization forming method for hollow parts | |
| CN2863296Y (en) | Hydraulic forming cavity die with sliding support | |
| CN108723194B (en) | A kind of forming device and method of complexity inside and outside wall cylindrical member | |
| CN110576088A (en) | bending forming method and bending device for large-diameter thin pipe | |
| CN101172295A (en) | Special die having movable force plug for the hydraulic forming of outer housing | |
| CN102107229B (en) | Method and device for molding small-angle bent pipe fitting by taking different curved surfaces as extrusion surfaces | |
| CN203076423U (en) | Forming support spring structure for air-suspension U-shaped bolt |
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 |