CN103707054A - Coordinated assembly method of a separation device with three butt joints - Google Patents

Abstract

The invention belongs to an assembly method, and particularly relates to a coordinated assembly method for a three-butt-joint-face separation device. It includes: the method comprises the following steps: measuring the height of the cutting cable protective cover, and positioning a cutting cable protective cover assembly on the frame; step two: a through hole is arranged on the frame according to the bottom hole on the protective cover component, and the hole is expanded; step three: removing the protective cover assembly; step four: tapping on the frame, and installing a steel wire thread sleeve; step five: positioning the butt joint pipe assembly on the frame, assembling an expansion pipe according to the position of the butt joint pipe assembly, and adjusting the insertion depth of the expansion pipe to meet the design requirement; step six: assembling an expansion pipe protective cover, and measuring while assembling; step seven: positioning and fastening the expansion pipe protective cover; step eight: detaching the protective cover and the flat tube, and repeating the second step to the fourth step until the trial assembly and the tapping work of the whole device are completed; step nine: formally installing a cutting rope protection cover, a flat tube and an expansion tube protection cover; step ten: retesting the assembly size of the protective cover, and comparing with the test assembly data; step eleven: and installing a positioning pin and a guide pin, and performing trial butt joint with the separated sections. The invention has the following effects: the requirements of assembly strength and coordination are met, and the emission requirement is met.

Description

A kind of separator Coordinative assembling method of three interfaces

Technical field

The invention belongs to assembly method, be specifically related to a kind of separator Coordinative assembling method of three interfaces.

Background technology

At present, only have two interfaces on the separator of domestic general Aerospace Products, can only control two portion's section products and carry out separation, separation point position is all in centre.The assembling of common separation device all adopts traditional drilling and bolt connection, easily causes the problems such as docking is inharmonious, parting surface inaccuracy.And the assembling of common separation device can only guarantee first separation, be difficult to solve a repeatedly difficult problem for head-shield separation.

Multipair junction separator generally has three and above interface, adopts and weakens groove control separation point position, as shown in Figure 1.Owing to can not taking into account the assembly precision of other parting surface, therefore existing assembly technology cannot be used on this multipair junction separator.After the upper and lower protective cover Product Assembly of this separator completes, before priming system is installed, also need to pull down, therefore must guarantee no-float, harmony is had relatively high expectations.The assembly method of multipair junction separator, accurately locates protective cover on the one hand, guarantee that flexible linear shaped charge or expansion tube and protective cover coordination do not interfere, and protective cover gap is even, effectively brings into play protective effect; Can control on the other hand and weaken groove and flexible linear shaped charge and align precision and be not less than 0.5mm, guarantee accurate separation.

Summary of the invention

A kind of separator Coordinative assembling method that the object of this invention is to provide three interfaces.

The present invention is achieved in that a kind of separator Coordinative assembling method of three interfaces, comprises the steps:

Step 1: measure the height of flexible linear shaped charge protective cover, positional dissection rope protective cover assembly, chooses 48 point measurements and pack the height after assembly on frame, is adjusted to height fluctuation value and is less than 0.2mm, and Assurance component packs rear gapless into;

Step 2: press bottom outlet on protective cover assembly to open-work on frame, and reaming;

Step 3: protective cover assembly is pulled down, by the bottom outlet reaming on assembly to designing requirement diameter;

Step 4: tapping on frame, steel-wire screw-socket is installed;

Step 5: locate butt tube assembly on frame, and press the position assembling expansion tube of butt tube assembly, adjust expansion tube insertion depth and reach designing requirement;

Step 6: assembling expansion tube protective cover, assembling limit, limit is measured, and is adjusted between each protective cover gap evenly and is less than 2mm;

Step 7: expansion tube protective cover location is clamped, by the bottom outlet on protective cover to open-work on frame, and reaming;

Step 8: pull down protective cover and flat tube, repeating step two～step 4 step is until complete that the trial assembly of whole device is joined and tapping work;

Step 9: with reference to examination installation step, formally pack flexible linear shaped charge protective cover, flat tube and expansion tube protective cover into, mounting portion screw;

Step 10: the fitted position of repetition measurement protective cover, and join Data Comparison with trial assembly, deviation is not more than 0.2mm; Occur deviation again trial assembly join, adjusting hole position;

Step 11: alignment pin, guide finger are installed, and are related to separated portion's section and try to dock.

The separator Coordinative assembling method of a kind of three interfaces as above, wherein, described step 1 comprises that flexible linear shaped charge protective cover assembly is comprised of protective cover and priming adapter two parts, before assembling, first two parts are connected with bolt with pin, form full circle, make it to become flexible linear shaped charge protective cover assembly, measuring and protecting cover height h, the depth H of groove on frame, record size, assembly is pressed to quadrant location, trial assembly enters in the groove of frame, measuring and protecting cover upper end is apart from the distance L of frame end face, by contrast h, H, the laminating gap that tri-numerical value of L can draw protective cover bottom surface and frame groove face, to guarantee that protective cover is seated, be that flexible linear shaped charge groove center aligns with weakening groove, by experimental study, three numerical value fluctuating ranges are not more than 0.2 and can guarantee rigging position,

After preliminary assembling, by the bottom outlet on protective cover, to open-work on frame, pull down protective cover; tapping on frame, dress steel-wire screw-socket, ressemble flexible linear shaped charge protective cover assembly, by quadrant, aligns; on circumference, choose 6 mounting screws, complete the assembling of flexible linear shaped charge protective cover.

The separator Coordinative assembling method of a kind of three interfaces as above, wherein, described step 5 comprises: before the assembling of expansion tube protective cover, need to install flat tube, adjustment installs rear assembling protective cover, protective cover needs the debugging of assembling limit, limit, should guarantee that each intersegmental gap is even, adjust again gap between each section and be less than 2mm, after trial assembly completes, on each segment protect cover, carry out one by one mark, later each dismounting must reset by this mark, pull down protective cover and flat tube, drilling tapping on frame, steel-wire screw-socket is installed, and reaming on protective cover, after drilling work and airtight having checked, by flat tube, the assemblies such as protective cover reset, and mounting screw, harmony with checking protective cover end-state.

The separator Coordinative assembling method of a kind of three interfaces as above, wherein, described step 8 comprises: 8.1 flat tube sectional dimensions are controlled

Adopt the pipe of (Φ 13 * 0.85) mm to press flat tube, ratio of semi-minor axis length is 16.4:7=2.34, be that major axis is 2.34 times of minor axis length, the distortion of flat tube pressing process middle section is very inhomogeneous: the distortion of surperficial circular arc place is maximum, also the most complicated, it not only bears the deformation force of self, also to be subject to neutral line tension attenuation in addition, neutral line with interior pressurized thickening, so as reach the sectional dimension of Feng's karman curve requirement, no matter be technique, or Fixture Design, is selecting resilience parameter all to need emphasis to consider

By theory, calculate known pipe cylindrical development size 41mm, the length of run that designs given flat tube major and minor axis is that 2 * 3.5 * π+2 * (16.4-7) are also 41mm, under such condition, on the flattening formation theory of flat tube, is feasible,

By testing the shaping dies of finally having determined groove type, controlled the distortion at Feng's karman curve R place, solved overproof problem, end face two terminal circle arc blow rule,

8.2 flat tube twists are controlled

Feng's karman curve flat tube the longest 1 is for 4600mm(is containing process allowance), because length is long, the effective active length 2000mm of mould, inevitably there is the compressing overlength flat tube of multistage, the transition section twist that how to guarantee multistage compacting is no more than 1.5mm/m becomes a compressing primary difficult problem

During for fear of sectional forming, the upper and lower flat segments in changeover portion joint has obvious impression, processes the hypotenuse transition region of certain length when making mould at patrix, efficiently solves the difficult problem that the transition position that joins leaves impression,

In order better to control twist, after the last period Pipe forming, manufactured and designed diaphragm frock, the distortion that in the time of can effectively preventing section pipe compacting below, leading portion pipe causes because of internal pressurization,

8.3 flat tube shaped depressions are controlled

The girth that should guarantee moulding front and back pipe during compacting is constant, guarantee that after being shaped, the moulding depression of upper lower plane can not be greater than 0.1mm simultaneously, to compressing, proposed very high requirement, must carry out a large amount of tests and technique is groped, following control program has finally been determined in test:

8.3.1 tube interior pressurization: in order to prevent that light-wall pipe from producing depression under die pressure effect, by special-purpose testing stand, at tube interior, passed into the water of certain pressure, supporting role by liquid prevents the depression in pipe flattening process, by repetition test, finally determines that overpressure value is 8MPa～10MPa;

8.3.2 flatten moulding for many times: by repetition test, finally determined and adopted 180 °, the pipe of repeatedly overturning, flattened the process of moulding, steel pipe is out of shape gradually for 5～6 times, reduced once compressing, metal has little time distortion, and R place is subject to restrain the shaped depression of the pipe upper surface of causing

8.4 flat tube bending forming technology

Bending forming Feng karman curve after steel pipe flattens, Feng's karman curve flat tube ratio of semi-minor axis length is 16.4:7=2.34, due to crooked along long axis direction, therefore section deformation is very inhomogeneous, with respect to the easier wrinkling and distortion along short-axis direction bending, realizing in which way the problems such as Feng's karman curve shape of tube bending and wall light wall pipe BENDING PROCESS springback calculation becomes key and the difficult point of bending forming

By Feng's karman curve equation, calculate each bending point and angle, use special technological equipment to carry out bending, by inspection template, verify, solve and guaranteed shape, dimensional requirement, flatness, twist, deflection have effectively been controlled, the defects such as crackle, wrinkling, ovality is overproof have been avoided, simultaneously, in technique, adopt predetermined length bending, directional curvature and the crooked rear brake forming that methods such as (being mainly the correction of pattern line tempte) has realized Feng's karman curve flat tube of revising, mainly taked following technological measure:

Wrinkling during a. for fear of flat tube bending, the twist of assurance bending flat pipe, has manufactured and designed the bending mould with groove, and the width of groove is identical with flat tube minor axis dimension;

B. accurate technology rebound value, considers the factors such as arc length of modulus of elasticity, pipe wall thickness and the sweep of tubing, by test and theoretical calculating, finally determines that mold profile is that radius is 1/4 circular arc of 1m;

C. the length variations due to pipe in BENDING PROCESS comprises stretching and bending elongation, its numerical value changes with the material of pipe, size, bending diameter, angle of bend etc., Feng's karman curve flat tube has adopted segmentation bending to replace the method for first order buckling, integral plaster is revised shaping by model, realized the brake forming of Feng's karman curve flat tube

Before flat tube assembling, gusset plate has been riveted complete, and do airtight inspection, for guaranteeing not damage body, assembling repaiies the manufactured head file on gusset plate to lower than surperficial 0.1mm, install before flat tube, first at location, quadrant place butt tube assembly, take butt tube assembly as benchmark trial assembly flat tube, during assembling, first fill flat tube right side, guarantee to insert distance and be not less than 12, left side flat tube and butt tube assembly are compared, guarantee butt tube component assembling correct position, flat tube left side insertion amount adjusts to 10 to 12, file and repair at unnecessary place, this kind of assembly method effectively guaranteed the docking length of flat tube and the rigging position of butt tube assembly.

The significant beneficial effect of the present invention is: formed complete multipair junction separator Coordinative assembling theoretical method, comprised the detailed process parameter that the each several part assemblings such as expansion tube, protective cover, flexible linear shaped charge protective cover are controlled.This kind of assembly method can meet assembling intensity, harmony requirement, and by emission test, separation accuracy can meet transmitting needs completely.In addition, this kind of assembly method can also reach certain airtight requirement, at external pressure 0.35MPa, keeps in 60min situation, and internal pressure rises and is no more than 0.02MPa, and local leak rate is lower than 1 * 10 ^-7pa.m ³/ s.

Accompanying drawing explanation

Fig. 1 is three interface separator product profiles.

In figure: 1. frame, 2. cutting lock protective cover assembly, 3. flat tube, 4. expansion tube protective cover, 5. screw.

The specific embodiment

A separator Coordinative assembling method for three interfaces, comprises the steps:

Step 1: measure the height of flexible linear shaped charge protective cover, positional dissection rope protective cover assembly, chooses 48 point measurements and pack the height after assembly on frame, is adjusted to height fluctuation value and is less than 0.2mm, and Assurance component packs rear gapless into;

Flexible linear shaped charge protective cover assembly is comprised of protective cover and priming adapter two parts, before assembling, first two parts is connected with bolt with pin, forms full circle, makes it to become flexible linear shaped charge protective cover assembly.On measuring and protecting cover height h, frame, the depth H of groove, records size.Assembly is pressed to quadrant location, and trial assembly enters in the groove of frame, and measuring and protecting cover upper end is apart from the distance L of frame end face.The laminating gap that can draw protective cover bottom surface and frame groove face by contrast h, H, tri-numerical value of L, to guarantee that protective cover is seated, flexible linear shaped charge groove center aligns with weakening groove.By experimental study, three numerical value fluctuating ranges are not more than 0.2 and can guarantee rigging position.

After preliminary assembling, by the bottom outlet on protective cover, to open-work on frame, pull down protective cover, tapping on frame, fill steel-wire screw-socket.Ressemble flexible linear shaped charge protective cover assembly, by quadrant, align, on circumference, choose 6 mounting screws, complete the assembling of flexible linear shaped charge protective cover.

Step 2: press bottom outlet on protective cover assembly to open-work on frame, and reaming;

Step 3: protective cover assembly is pulled down, by the bottom outlet reaming on assembly to designing requirement diameter;

Step 4: tapping on frame, steel-wire screw-socket is installed;

Step 5: locate butt tube assembly on frame, and press the position assembling expansion tube of butt tube assembly, adjust expansion tube insertion depth and reach designing requirement;

Before the assembling of expansion tube protective cover, need to install flat tube, adjust and install rear assembling protective cover.Protective cover needs the debugging of assembling limit, limit, should guarantee that each intersegmental gap is even, adjusts again gap between each section and is less than 2mm.After trial assembly completes, carry out one by one mark on each segment protect cover, later each dismounting must reset by this mark.Pull down protective cover and flat tube, drilling tapping on frame, installs steel-wire screw-socket, and reaming on protective cover.After drilling work and airtight having checked, the assemblies such as flat tube, protective cover are resetted, and mounting screw, to verify the harmony of protective cover end-state.

Step 6: assembling expansion tube protective cover, assembling limit, limit is measured, and is adjusted between each protective cover gap evenly and is less than 2mm;

Step 7: expansion tube protective cover location is clamped, by the bottom outlet on protective cover to open-work on frame, and reaming;

Step 8: pull down protective cover and flat tube, repeating step two～step 4 step is until complete that the trial assembly of whole device is joined and tapping work;

8.1 flat tube sectional dimensions are controlled

Adopt the pipe of (Φ 13 * 0.85) mm to press flat tube, ratio of semi-minor axis length is 16.4:7=2.34, be that major axis is 2.34 times of minor axis length, the distortion of flat tube pressing process middle section is very inhomogeneous: the distortion of surperficial circular arc place is maximum, also the most complicated.It not only bears the deformation force of self, also will be subject to neutral line tension attenuation in addition, neutral line with interior pressurized thickening, thus as reached the sectional dimension of Feng's karman curve requirement, no matter be technique, or Fixture Design, selecting resilience parameter all to need emphasis to consider.

By theory, calculate known pipe cylindrical development size 41mm, the length of run that designs given flat tube major and minor axis is that 2 * 3.5 * π+2 * (16.4-7) are also 41mm, under such condition, on the flattening formation theory of flat tube, is feasible.

By testing the shaping dies of finally having determined groove type, controlled the distortion at Feng's karman curve R place, solved overproof problem, end face two terminal circle arc blow rule.

8.2 flat tube twists are controlled

Feng's karman curve flat tube the longest 1 is for 4600mm(is containing process allowance), because length is long,, inevitably there is the compressing overlength flat tube of multistage in the effective active length 2000mm of mould.The transition section twist that how to guarantee multistage compacting is no more than 1.5mm/m becomes a compressing primary difficult problem.

During for fear of sectional forming, the upper and lower flat segments in changeover portion joint has obvious impression, processes the hypotenuse transition region of certain length when making mould at patrix, efficiently solves the difficult problem that the transition position that joins leaves impression.

In order better to control twist, after the last period Pipe forming, manufactured and designed diaphragm frock, the distortion that in the time of can effectively preventing section pipe compacting below, leading portion pipe causes because of internal pressurization.

8.3 flat tube shaped depressions are controlled

During compacting, should guarantee that the girth of pipe is constant before and after moulding, guarantee that the moulding depression of upper lower plane after being shaped can not be greater than 0.1mm simultaneously, to compressing, propose very high requirement, must carry out a large amount of tests and technique is groped.Following control program has finally been determined in test:

8.3.1 tube interior pressurization: in order to prevent that light-wall pipe from producing depression under die pressure effect, passed into the water of certain pressure by special-purpose testing stand at tube interior, the supporting role by liquid prevents the depression in pipe flattening process.By repetition test, finally determine that overpressure value is 8MPa～10MPa;

8.3.2 flatten moulding for many times: by repetition test, finally determined and adopted 180 °, the pipe of repeatedly overturning, flatten the process of moulding 5～6 times, steel pipe is out of shape gradually, reduced once compressing, metal has little time distortion, and R place is subject to restrain the shaped depression of the pipe upper surface of causing.

8.4 flat tube bending forming technology

Bending forming Feng karman curve after steel pipe flattens, Feng's karman curve flat tube ratio of semi-minor axis length is 16.4:7=2.34, due to crooked along long axis direction, so section deformation is very inhomogeneous, with respect to the easier wrinkling and distortion along short-axis direction bending.Realizing in which way the problems such as Feng's karman curve shape of tube bending and wall light wall pipe BENDING PROCESS springback calculation becomes key and the difficult point of bending forming.

By Feng's karman curve equation, calculate each bending point and angle, use special technological equipment to carry out bending, by inspection template, verify, solve and guaranteed shape, dimensional requirement, effectively control flatness, twist, deflection, avoided the defects such as crackle, wrinkling, ovality is overproof.Meanwhile, in technique, adopt predetermined length bending, directional curvature and the crooked rear brake forming that methods such as (being mainly the correction of pattern line tempte) has realized Feng's karman curve flat tube of revising.Mainly taked following technological measure:

Wrinkling during a. for fear of flat tube bending, the twist of assurance bending flat pipe, has manufactured and designed the bending mould with groove, and the width of groove is identical with flat tube minor axis dimension;

B. accurate technology rebound value.Consider the factors such as arc length of modulus of elasticity, pipe wall thickness and the sweep of tubing, by test and theoretical calculating, finally determine that mold profile is that radius is 1/4 circular arc of 1m;

C. the length variations due to pipe in BENDING PROCESS comprises stretching and bending elongation, its numerical value changes with the material of pipe, size, bending diameter, angle of bend etc., Feng's karman curve flat tube has adopted segmentation bending to replace the method for first order buckling, integral plaster is revised shaping by model, has realized the brake forming of Feng's karman curve flat tube.

Flat tube has been riveted gusset plate complete before assembling, and does airtight inspection.For guaranteeing not damage body, assembling repaiies the manufactured head file on gusset plate to lower than surperficial 0.1mm.Install before flat tube, first, at location, quadrant place butt tube assembly, take butt tube assembly as benchmark trial assembly flat tube.During assembling, first fill flat tube right side, guarantee to insert distance and be not less than 12, left side flat tube and butt tube assembly are compared, and guarantee butt tube component assembling correct position, and flat tube left side insertion amount adjusts to 10 to 12, and file and repaiies at unnecessary place.This kind of assembly method effectively guaranteed the docking length of flat tube and the rigging position of butt tube assembly.

Step 9: with reference to examination installation step, formally pack flexible linear shaped charge protective cover, flat tube and expansion tube protective cover into, mounting portion screw;

Step 10: the fitted position of repetition measurement protective cover, and join Data Comparison with trial assembly, deviation is not more than 0.2mm; Occur deviation again trial assembly join, adjusting hole position;

Step 11: alignment pin, guide finger are installed, and are related to separated portion's section and try to dock.

In each step, unspecified step all adopts existing techniques in realizing above.

Claims (4)

1. a method for coordinating the assembly of a separating device of three butt joint surfaces, is characterized in that: comprises the following steps: Step 1: Measure the height of the cutting cable protective cover, position the cutting cable protective cover assembly on the frame, select 48 points to measure the height after the assembly is installed, and adjust to a height fluctuation value less than 0.2mm to ensure that there is no gap after the assembly is installed; Step 2: Press the bottom hole on the protective cover assembly to penetrate the frame and ream the hole; Step 3: Remove the protective cover assembly, and ream the bottom hole on the assembly to the diameter required by the design; Step 4: Tap on the frame and install the wire screw sleeve; Step 5: Position the butt joint assembly on the frame, assemble the expansion tube according to the position of the butt joint assembly, and adjust the insertion depth of the expansion tube to meet the design requirements; Step 6: Assemble the protective cover of the expansion tube, measure while assembling, and adjust until the gap between the protective covers is even and less than 2mm; Step 7: Position and tighten the protective cover of the expansion tube, press the bottom hole on the protective cover to penetrate the hole on the frame, and ream the hole; Step 8: Remove the protective cover and flat tube, repeat steps 2 to 4 until the trial assembly and tapping of the entire device are completed; Step 9: Referring to the trial assembly steps, formally install the cutting cable protection cover, flat tube and expansion tube protection cover, and install some screws; Step 10: Retest the assembly size of the protective cover and compare it with the trial assembly data. The deviation is not greater than 0.2mm; if there is a deviation, re-test the assembly and adjust the hole position; Step 11: Install positioning pins and guide pins, and conduct trial docking with the sections involved in separation. 2. A method for coordinating assembly of a separation device with three butt joints as claimed in claim 1, characterized in that: said step 1 includes the cutting cable protective cover assembly consisting of a protective cover and a detonating joint, and prior to assembly, the The two parts are connected by pins and bolts to form a complete circle, making it a cutting cable protective cover assembly, measure the height h of the protective cover, and the depth H of the groove on the frame, record the dimensions, position the assembly according to the quadrant, and try to fit it into the groove of the frame , measure the distance L between the upper end of the protective cover and the end face of the frame, and compare the three values of h, H, and L to obtain the bonding gap between the bottom surface of the protective cover and the groove surface of the frame, so as to ensure that the protective cover is assembled in place, that is, cut the cable groove The center is aligned with the weakening groove. Through experimental research, the fluctuation range of the three values is not greater than 0.2 to ensure the assembly position. After the preliminary assembly is completed, press the bottom hole on the protective cover to penetrate the upper frame, remove the protective cover, tap the thread on the frame, install the wire screw sleeve, reassemble the cutting cable protective cover assembly, align according to the quadrant, on the circumference Select 6 mounting screws to complete the assembly of the cutting cable protection cover. 3. A coordinated assembly method for a separation device with three butt joints as claimed in claim 2, characterized in that: said step 5 includes: installing a flat tube before assembling the protective cover of the expansion tube, and assembling the protective cover after adjustment and installation , the protective cover needs to be assembled and debugged at the same time. It is necessary to ensure that the gap between each section is uniform, and to adjust the gap between each section to be less than 2mm. After the trial assembly is completed, mark each section of the protective cover one by one. Reset this mark, remove the protective cover and flat tube, tap the hole on the frame, install the wire screw sleeve, and ream the hole on the protective cover. Components are reset and screws are installed to verify the coordination of the final state of the guard. 4. The coordinated assembly method of a separation device with three butt joint surfaces as claimed in claim 3, characterized in that: the eighth step includes: 8.1 Flat tube cross-sectional size control (Φ13×0.85) mm round tube is used to press and form a flat tube. The ratio of the long axis to the short axis is 16.4:7=2.34, that is, the long axis is 2.34 times the length of the short axis. The cross-sectional deformation of the flat tube is very uneven during the pressing process. : The deformation of the surface arc is the largest and the most complicated. It not only bears its own deformation force, but also suffers from tension and thinning outside the neutral layer, and compression and thickening inside the neutral layer. Therefore, if it meets the requirements of the von Karman curve The cross-sectional size, whether it is process or tooling design, needs to be considered in the selection of springback parameters. Through theoretical calculation, it can be known that the expanded size of the outer circle of the round tube is 41mm, and the expanded length of the long and short axis of the given flat tube is 2×3.5×π+2×(16.4-7), which is also 41mm. Under such conditions, the flattened tube The theory of flattening above is feasible, Through the test, the groove-type forming die was finally determined, the deformation at the R of the von Karman curve was controlled, and the problem of out-of-tolerance was solved. The arc deformation at both ends of the end face was regular, 8.2 Flat tube torsion control The longest Von Karman curve flat tube is 4600mm (including the process allowance). Due to the length being too long, the effective working length of the mold is 2000mm. It is inevitable that there will be multi-stage pressing to form an ultra-long flat tube. How to ensure the cross-section of the transition section of multi-stage pressing The torsion does not exceed 1.5mm/m has become the primary problem of compression molding, In order to avoid the obvious indentation of the upper and lower straight sections at the junction of the transition section during segmental molding, a certain length of beveled edge transition area is processed on the upper mold when making the mold, which effectively solves the problem of leaving indentations at the junction transition. problem, In order to better control the torsion, after the former section of the tube is formed, a protective film tooling is designed and manufactured, which can effectively prevent the deformation of the front section of the tube due to internal pressure when the latter section of the tube is pressed. 8.3 Flat tube forming sag control When pressing, it is necessary to ensure that the circumference of the pipe before and after forming is unchanged, and at the same time ensure that the forming depression of the upper and lower planes after forming is not greater than 0.1mm, which puts forward high requirements for pressing forming, and a large number of tests and process explorations must be carried out. The test is finally determined. The following control scheme is adopted: 8.3.1 Internal pressure of the pipe: In order to prevent the thin-walled pipe from being sunken under the pressure of the mold, a certain pressure of water is introduced into the inside of the pipe through a special test bench, and the support of the liquid is used to prevent the pipe from being flattened during the flattening process. Depression, the pressure in the pipe is finally determined to be 8MPa ~ 10MPa through repeated tests; 8.3.2 Multiple flattening: Through repeated tests, the process of turning the pipe 180° multiple times and flattening 5 to 6 times is finally determined, so that the steel pipe is gradually deformed, and one pressing is reduced. The metal has no time to deform, and R The formed depression on the upper end surface of the tube caused by restraint at the place, 8.4 Flat tube bending forming technology After the steel pipe is flattened, it is bent to form a Von Karman curve. The ratio of the long and short axes of the Von Karman curve flat tube is 16.4:7=2.34. Due to bending along the long axis, the section deformation is very uneven, which is easier to bend than along the short axis. Wrinkle and deformation, how to realize the Von Karman curve shape of the tube bending and the springback calculation of the thin-walled tube bending process have become the key and difficult points of bending forming. Calculate each bending point and angle through the Von Karman curve equation, use special process equipment for bending, and verify through the inspection model, solve and guarantee the shape and size requirements, effectively control the flatness, torsion, and deformation, and avoid Defects such as cracks, wrinkles, and ellipticity are out of tolerance. At the same time, methods such as predetermined length bending, directional bending, and post-bending correction (mainly model line model correction) are used to realize the bending of Von Karman curve flat tubes. The main The following technological measures have been taken: a. In order to avoid wrinkling when the flat tube is bent and ensure the torsion of the bent flat tube, a bending mold with a groove is designed and manufactured, and the width of the groove is the same as the short axis of the flat tube; b. Accurate technical springback value, comprehensively considering factors such as the elastic modulus of the pipe material, pipe wall thickness and arc length of the bending part, through experiments and theoretical calculations, it is finally determined that the mold contour is a 1/4 arc with a radius of 1m; c. Since the length change of the pipe during the bending process includes stretching and bending elongation, its value varies with the material, size, bending diameter, bending angle, etc. of the pipe, and the Von Karman curve flat pipe is replaced by segmental bending The method of one-time bending, the whole body is attached to the template for correcting and forming, and the bending and forming of the von Karman curve flat tube is realized. Before the assembly of the flat tube, the corner piece has been riveted and airtight inspection has been carried out. In order to ensure that the tube body is not damaged, the rivet head on the corner piece is repaired to 0.1mm below the surface during assembly. Before installing the flat tube, first position it in the quadrant For the butt joint assembly, try to install the flat tube based on the butt joint assembly. When assembling, first install the right side of the flat tube to ensure that the insertion distance is not less than 12. Compare the left flat tube with the butt joint assembly to ensure that the assembly position of the butt joint assembly is correct. , Adjust the insertion amount on the left side of the flat tube to 10 to 12, and file the excess. This assembly method effectively ensures the butt joint length of the flat tube and the assembly position of the butt joint assembly.

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