A kind of high intensity or the hot formed method of inductile material hollow unit low pressure
The present invention relates to machinery production field, more particularly to a kind of high intensity or inductile material hollow unit low pressure heat at
The method of shape.
Due to hollow section component high composite bending modulus and modulus of rigidity, it is considered to be realize structure lightened best knot
Configuration formula.It is widely used in the industries such as Aeronautics and Astronautics, automobile and bicycle.Fluid internal pressure forming is to process the elder generation of such component
Into forming technique.The technical principle of fluid internal pressure forming is to apply high pressure medium to initial blank inside to keep blank section all
Length increases and shapes the hollow member of different cross section form.Its essence deformed is parison swell deformation.But this kind of distorted pattern
Formula has limitation, it is impossible to be used in intensity is higher or the forming of the relatively low material of plasticity, reason show as following several respects：
One, for needing the material of phase transformation strengthening that can not realize heat treatment in forming process.
Secondly, since internal pressure is unique deformation driving force, be likely to drive tubing complete when only pressure reaches very high
Forming, it is therefore necessary to be equipped with dedicated high-power booster, while by superhigh pressure sealing technology restriction, form high strength or low modeling
It is difficult when property material hollow unit.In addition, to provide enough mold clamping forces, it is necessary to use large-tonnage equipment.The above problem
The engineer application of the technology is hindered significantly.
Third, since fluid internal pressure forming mainly produces required odd-shaped cross section by dilatancy, and expand and become
Shape pattern belongs to double tensile stress states and the lower material of plasticity is easily ruptured, and is accordingly used in skill when Al alloys andMg alloys
There is very big defect in art.
Fourth, its elasticity modulus is generally relatively low for Materials with High Strength, elasticity restores violent when forming, room temperature fluid internal pressure at
The form accuracy of shape it is difficult to ensure that.
There is scholar to propose hot interior pressing formation, although this method solves the problems, such as forming limit, but exacerbate wall thickness not
Equal problem, and the limitation of heated medium booster and the restriction of high pressure gas safety problem, are unsuitable for engineer application.
For these reasons, switch to, to be bent into primary deformable pattern, change fluid internal pressure forming to be expanded to unique change
The drawbacks of shape pattern, and internal pressure caused by member section variation in high temperature volumetric expansion and forming process is made full use of to increase certainly
Characteristic provides driving force for deformation, avoids under traditional handicraft to the depending on unduly of booster, drip molding springback capacity is big, form accuracy
Low and poor evenness of wall thickness problem reduces technology difficulty, widens the technique scope of application, improves the original that forming quality is the present invention
The purpose of the present invention provides a kind of high intensity or inductile material aiming at drawbacks described above of the existing technology
The hot formed method of hollow unit low pressure mainly solves existing apparatus and process forming high intensity or inductile hollow unit
When, resistance of deformation is big, and drip molding evenness of wall thickness difference and d type precision be not high, easily ruptures, and efficiency is low and can not same stepping
The problem of row heat treatment.
A kind of high intensity or the hot formed method of inductile material hollow unit low pressure that the present invention mentions, including following step
Step 1：Mold prepares, and designs corresponding left electrode according to Components Shape first（2）, left sealing punch（3）, on
Mold（15）, right electrode（16）, right sealing punch（17）With lower mold（21）, the upper mold（15）With upper table（11）
Connection, lower mold（21）With lower table（1）Connection；Left sealing punch（3）Pass through media filler channel（5）It is opened with cooling medium
It closes（4）With the cooling medium source in outside（6）Connection, while passing through check valve（7）, pressure reducing valve（8）And air inlet switch（10）With outside
Gas medium source（9）Connection；Right sealing punch（17）It is provided with pressure release passage（19）And and relief valve（18）Connection；Left electrode（2）
With right electrode（16）Pass through conducting wire（12）And power switch（13）With power supply（14）Connection；
Step 2：Initial pipe prepares, and selects the suitably initial pipe of size, wherein the section girth of initial pipe
Equal to 0.5-1.5 times of whole drip molding perimeter of section, and initial pipe length is more than part length；
Step 3：Left sealing punch（3）With right sealing punch（17）Blank end is sealed, then moves on to specific bit together
Step 4：Left electrode（2）With right electrode（16）It moves to and is contacted with initial pipe, wherein left electrode setting is left close
The right side of punch is sealed, and right electrode is arranged in the left side of right sealing punch；
Step 5：Adjust pressure reducing valve（8）, pressure is reduced into concrete technology desired value, then opens air inlet switch（10）To
Pipe internal ventilation body medium；
Step 6：Power switch（13）It is closed, the pipe that sealing is powered integrally is moved into lower mold（21）Cavity in, and
Traveling time is no more than 60 seconds；
Step 7：Upper mold（15）Downlink, compression pipe bring it about flexural deformation, and pipe sectional area reduces therewith, interior
Portion's pressure further increases, and pipe is promoted further to shape, and passes through relief valve in whole process（18）Air pressure inside is controlled, until
Mold is closed；
Step 8：Pressurize continues to pipe to shape；
Step 9：Power switch（13）It disconnects, opens cooling medium switch（4）, to pipe inside lead to cooling medium, pressure
Relief valve unlatching is increased to, while gas flow and ventilation duration meet the requirement of drip molding cooling technique；
Step 10：Close cooling medium switch（4）, left sealing punch（3）, right sealing punch（17）, left electrode（2）The right side and
Electrode（16）It retreats to drip molding taking-up is not influenced, opens mold, take out drip molding（22）.
Preferably, in above-mentioned step five, 0 ~ 50MPa is reduced to for Materials with High Strength pressure, inductile material pressure reduces to 0
Preferably, above-mentioned power supply is pulse current power supply
Preferably, the designated position in step 3 is lower mold（21）Or it is convenient for connection electrode region.
Preferably, above-mentioned initial pipe（20）Using high-strength material or inductile material.
Preferably, above-mentioned cooling medium source（6）For cryogenic gas or liquid；Gas medium is room temperature air or low temperature gas
The beneficial effects of the invention are as follows：
First, the temperature being had by oneself in technical process is made full use of to increase with internal pressure increase caused by volume change as deformation
Driving force is not necessarily to optional equipment booster, simple process and low cost；
Second, directly being quenched to component in mold cavity using the cooling medium with certain pressure, be conducive to
Ensure the geometric accuracy of drip molding, and improves process efficiency；
Third, since the deformation pattern of the technique is based on flexural deformation, avoiding hardenability value under high temperature reduces not
Profit influences, and drip molding evenness of wall thickness is good, technique strong applicability；
Fourth, quenched out of hollow section member cavity by cooling medium, since medium and component are in direct contact,
Cooling velocity is fast and uniform, and performance is unanimously good；
Fifth, flexible deformation is extremely low under hot forming, drip molding is easily guaranteed that almost without rebound, drip molding form accuracy；
Sixth, by large power supply directly to heating of pipe blank, rate is fast, and thermal losses is low, overcomes traditional thermal state fluid
Internal pressure forming efficiency is low, the shortcomings that cannot meeting engineer application；
Reasonable design of the present invention, reliable operation, significant effect have stronger promotional value.
Description of the drawings
Fig. 1 is the structural schematic diagram of the mold of the present invention；
Fig. 2 is the A-A structure charts of the mold of the present invention；
Fig. 3 is mold clamping and quenching principle schematic diagram；
Fig. 4 is the B-B structure charts of Fig. 3；
In upper figure：Lower table 1, left electrode 2, left sealing punch 3, cooling medium switch 4, media filler channel 5, cooling
Medium source 6, check valve 7, pressure reducing valve 8, gas medium source 9, air inlet switch 10, upper table 11, conducting wire 12, power switch 13,
Power supply 14, upper mold 15, right electrode 16, right sealing punch 17, relief valve 18, pressure release passage 19, initial pipe 20, lower mold
21, drip molding 22.
Specific implementation mode
With reference to attached drawing 1-2, the invention will be further described：
A kind of high intensity or inductile material hollow unit low pressure thermal forming device that the present invention mentions, including left electrode 2,
Left sealing punch 3, upper mold 15, right electrode 16, right sealing punch 17 and lower mold 21, it is characterized in that：The upper mold 15
It is connect with upper table 11, lower mold 21 is connect with lower table 1；Left sealing punch 3 passes through media filler channel 5 and cooling Jie
Matter switch 4 is connect with outside cooling medium source 6, while passing through check valve 7, pressure reducing valve 8 and air inlet switch 10 and extraneous gas Jie
Matter source 9 connects；Right sealing punch 17 is provided with pressure release passage 19 and is connect with relief valve 18；Left electrode 2 and right electrode 16 are by leading
Line 12 and power switch 13 are connect with power supply 14；
By left sealing punch 3 and right sealing punch 17 to 20 end part seal of initial pipe, and move on to designated position；Left electricity
Pole 2 and right electrode 16 are moved to be contacted with initial pipe 20, and left electrode 2 is arranged on the right side of left sealing punch 3, and right electrode 16
It is arranged in the left side of right sealing punch 17.
The section girth of above-mentioned initial pipe 20 is equal to 0.5-1.5 times of whole drip molding perimeter of section.
Above-mentioned power switch 13 is closed, and quickly integrally moves to the pipe that sealing is powered in the cavity of lower mold 21,
Wherein, traveling time is no more than 60 seconds.
Above-mentioned upper mold 15 brings it about flexural deformation by setting curve downlink, compression pipe, and pipe sectional area is therewith
Reduce, internal pressure increases, and pipe is promoted to shape, and air pressure inside is controlled by relief valve 18 in whole process.
With reference to attached drawing 3-4, a kind of high intensity or the hot formed side of inductile material hollow unit low pressure that the present invention mentions
Method includes the following steps：
Step 1：Mold prepares, and designs corresponding left electrode 2, left sealing punch 3, upper mold according to Components Shape first
15, right electrode 16, right sealing punch 17 and lower mold 21, above-mentioned same as the prior art, this is not repeated.Upper mold 15 and upper work
Make the connection of platform 11, lower mold 21 is connect with lower table 1.Left sealing punch 3 is switched by media filler channel 5 and cooling medium
4 connect with outside cooling medium source 6, while passing through check valve 7, pressure reducing valve 8 and air inlet switch 10 and the company of extraneous gas medium source 9
It connects.Right sealing punch 17 is provided with pressure release passage 19 and is connect with relief valve 18.Left electrode 2 and right electrode 16 pass through conducting wire 12 and electricity
Source switch 13 is connect with power supply 14.
Step 2：Initial pipe prepares, and it is the cross section week of initial pipe to select the suitably initial pipe of size, main points
Long close with the whole section girth of drip molding, the section girth of general initial pipe should be equal to whole drip molding perimeter of section
0.5-1.5 times.Initial pipe length should be greater than part length, and guarantee has enough sealing areas and electrode contact region.
Step 3：Left sealing punch 3 and right sealing punch 17 seal blank end, then move on to designated position together.
Sealing means are same as the prior art, this is not repeated.
Step 4：Left electrode 2 and right electrode 16 are moved to and are contacted with pipe, and main points are that left electrode should be in left sealing punch
Right side, and right electrode should ensure in the left side of right sealing punchl a It is less thanl b 。
Step 5：Pressure reducing valve 8 is adjusted, pressure is reduced into concrete technology desired value, then opens air inlet switch 10 to pipe
Internal ventilation body medium.Its main points is generally to reduce to 0 ~ 50MPa for Materials with High Strength pressure, and inductile material pressure generally reduces to
Step 6：Power switch 13 is closed, and quickly integrally moves to the pipe that sealing is powered in the cavity of lower mold 21,
Its main points is that traveling time is no more than 60 seconds.With the progress of energization, blank temperature constantly increases, under the flow stress of material
Drop, elongation percentage improves, while pipe internal gas expanded by heating, air pressure constantly increase.
Step 7：Upper mold 15 presses technique initialization curve downlink, and compression pipe brings it about flexural deformation, pipe sectional area
Reduce therewith, internal pressure further increases, and pipe is promoted further to shape, and inside is controlled by relief valve 18 in whole process
Air pressure maximum value is in concrete technology claimed range, until mold is closed.
Step 8：Pressurize certain time, main points are that pressurize continues to pipe to shape.
Step 9：Power switch 13 disconnects, and opens cooling medium switch 4, to pipe inside lead to cooling medium, and continue one
It fixes time, main points are that pressure increases to relief valve unlatching simultaneously, while gas flow and ventilation duration meet drip molding cooling technique
It is required that.
Step 10：It closes and cools down medium switch 4, after left sealing punch 3, right sealing punch 17, left electrode 2 and right electrode 16
Retreating to does not influence drip molding taking-up, opens mold, takes out drip molding 22.
Wherein, the power supply that the present invention mentions be pulse current power supply, pulse frequency 0-10000Hz, amplitude 0-100000A,
The power supply of voltage range 0-100000V.
Designated position in step 3 be lower mold 21 or just with connection electrode region；Under designated position in step 3 is
The interior cavity of mold 21；Designated position in step 3 is for ease of connection electrode region；
The high-strength material or inductile material that initial pipe uses, high-strength material are high-strength steel or titanium alloy, high-strength
Steel is 22MnB5, titanium alloy TC4；Inductile material is aluminium alloy or magnesium alloy, and aluminium alloy is 2000 systems, 5000 be 6000 systems
Or 7000 line aluminium alloy；
Cooling medium is cryogenic gas or liquid, and gas medium is room temperature air or cryogenic gas, and gas medium is low temperature