CN103394575A - Waveform furnace pipe spinning forming process - Google Patents

Abstract

The invention relates to a waveform furnace pipe spinning forming process. The waveform furnace pipe spinning forming process comprises the steps of (1) adjusting the rotating speed of a cylinder body to be 3.5-5pm and enabling a furnace pipe to be partially and evenly heated by the temperature of 750-850 DEG C at the heating wave band position, (2) moving a jacking pressing wheel to the heating wave band position to enable the jacking pressing wheel to be in contact with the surface of a cylinder joint to enable the jacking pressing wheel to be slowly fed, enabling the feeding quantity to be 1-2mm each time, continuously conducting feeding after the cylinder body rotates for one revolution, spinning while conducting heating until the waveform achieves the preset depth shape, meanwhile, tightening an adjusting screw nut on a furnace pipe tailstock clamp pressing disc shaft while spinning, enabling a furnace pipe heater to be a medium-frequency induction heater, enabling the using power of a medium-frequency power source to be 1000Hz-2500Hz, and enabling the heating time based on the wall thickness to be 1.5*min/mm. According to the waveform furnace pipe spinning forming process, when spinning is carried out, spinning crowded injury marks on the surface cannot be easily caused by the high temperature, and influences on the reduction quantity, the waveform height and the waveform pitch of the wall thickness are fewer.

Description

A kind of corrugated flue spinning forming process

Technical field

The present invention relates to a kind of forming and machining method of flue, particularly relate to a kind of forming and machining method of corrugated flue.

Background technology

In the oil burning boiler product, corrugated flue is the main pressure containing part of oil burning boiler, but manufacture corrugated flue, is the biggest problem of producing oil burning boiler.Control the Forming Quality of corrugated flue well, meet JB/T1619-2002 " shell boiler body manufacturing technology condition " and be and guarantee that the oil burning boiler quality uses the important step of safety.

Present domestic boiler maker adopts respectively according to the equipment and process technical merit of each factory the manufacturing process of corrugated flue:

1, cold-press moulding technique on forcing press, the deficiency of this forming technology:

1. the press equipment that needs is huge, the mold tooling complexity;

2. labor strength is high, and production efficiency is low;

3. owing to being that segmentation is colded pressing, must will partly cause flow harden in the cylindrical shell moulding through repeatedly repeatedly pressing arc, retain very large cold-working stress, so after flue cold moudling, must carry out the integrally annealed processing to eliminate stress.

2, rolled forming technique on the three-roller type special purpose machine tool, this moulding process deficiency:

1. equipment investment is large, and the waveform difference will have corresponding Samsung roller, and cost is larger;

2. the spreading volume is round repeatedly for cylindrical shell, and barrel soldering place difficult quality is ensured, moulding rear cylinder body stress is large, the palpus integrally annealed;

3. this Samsung roller rolls, and can't roll at present the cylindrical shell of thickness δ=20mm.

3, utilize heated by gas mould pressing on special purpose machine tool, the deficiency of this technique:

1. coal gas need to have special-purpose gas generator, and the fireman of specialty be arranged, and larger coal piling place (coal quarrel place) be arranged;

2. by coal, convert gas-fired to, higher to the quality requirement of coal, by coal, convert the coal gas loss to large.The hot spinning flue dust pollutes large to surrounding environment, workman's operating environment is poor;

3. heated by gas is ejected into the drum surface burning, and drum surface is easily caused to oxidation, shelling layer, when serious, cylindrical shell is had to the carburizing phenomenon.

Summary of the invention

The invention provides and a kind ofly can significantly reduce wall thickness reduction amount, waveform height error and, without the carburizing phenomenon, improve the forming and machining method of the corrugated flue of corrugated flue crudy.

Technical scheme of the present invention is:

A kind of corrugated flue spinning forming process comprises step:

1. adjust the speed of gyration 3.5 ~ 5pm of cylindrical shell, make flue 750～850 ℃ of heating wave band position local uniform heating;

2. the movable top pinch roller arrives heating wave band position, makes pinch roller contact shell ring surface, top slow feeding top pinch roller, and each amount of feeding, at 1 ~ 2mm, continues feeding again after cylindrical shell rotates a circle, and the heating of spinning limit, limit, until waveform reaches predetermined degree of depth shape; The adjusting nut on flue tailstock fixture platen axle is tightened on spinning limit, limit simultaneously;

3. after wave-shaped ring shapes, the heating wave band is continued to insulation, the time is for pressing wall thickness * min/mm; Exit again the top pinch roller, waveform pitch of transverse shifting top pinch roller and heater, by 1., 2. the step same method process next the joint waveform;

It is characterized in that: described flue heater is medium frequency induction heater, and described intermediate frequency power supply uses power to be 1000Hz ~ 2500Hz, and heat time heating time is for pressing wall thickness 1.5 * min/mm.

Beneficial effect of the present invention is:

1. Frequency Induction Heating has improved the quality of corrugated flue;

The comparison sheet unit of table 1 the present invention and contrast: mm

The applicant's discovery, heated by gas is high to the drum surface heating-up temperature, and the deep layer temperature is low, and the temperature of namely processing cylindrical shell is that ecto-entad presents a kind of step-like temperature difference.When press on pinch roller top in top, to be that ecto-entad presents a kind of step-like temperature difference inconsistent due to the temperature of cylindrical shell, caused so the inside and outside distortion of cylindrical shell also can be inconsistent, particularly thicker (as the thick-wall cylinder of δ=18 ~ 20mm) for cylindrical shell, during spinning, easily cause surface to occur that because surface temperature is high spinning squeezes the scar mark, affects attenuate amount, waveform height and waveform pitch that barrel is thick.

The permeability that beneficial effect 1. Frequency Induction Heating are stronger because electric current of intermediate frequency has, to the cylindrical shell homogeneous heating, like this when on top pinch roller top, pressing, to be that ecto-entad presents the temperature difference consistent due to the temperature of cylindrical shell particularly, it is consistent to have caused so the inside and outside distortion of cylindrical shell, be not easy to cause during spinning like this surface to occur that because temperature is high spinning squeezes the scar mark, and then affect attenuate amount, waveform height and the waveform pitch less (in Table 1) of wall thickness.

2. Frequency Induction Heating does not have the carburizing phenomenon to cylindrical shell with respect to documents, and the carburizing phenomenon is mainly that burning is unclean owing to there being coal during due to coal combustion, between bonnet and cylindrical shell, will there will be the carburizing phenomenon has been appearred in drum surface for a long time.

The accompanying drawing explanation

Fig. 1 represents the schematic diagram of corrugated flue Frequency Induction Heating;

Fig. 2 represents corrugated flue rotary pressing processing process schematic representation;

Sign 1 medium frequency capacitor 2 upper end Medium frequency induction solenoid 3 cylindrical shell 4 intermediate-frequency transformers in figure

5 lower end Medium frequency induction solenoid 6 top pinch roller 7 chuck 8 adjusting nut 9 centering chucks

10 tailstocks.

The specific embodiment

Below in conjunction with accompanying drawing, Frequency Induction Heating spinning corrugated flue technical process is further illustrated:

1, intermediate frequency power supply eddy-current heating schematic diagram (accompanying drawing 1)

2, the intermediate frequency power supply induction heating technology is applied to the heating of corrugated flue, key is designing and producing of medium frequency induction heater, for guaranteeing the heating effect of shell ring, minute upper end heater and lower end heater, heater coil is embedded in the magnetic conductor groove, and better heating effect can be arranged;

3, mould pressing principle

On the special spinning machine bed, adopt heating edge feeding top, intermediate frequency power supply limit pinch roller; The curve form of top pinch roller forces cylindrical shell heating part to be spun into corresponding curved surface;

4, flue cylindrical shell heating

4.1 the flue shell ring adds the permeability of heat utilization electric current of intermediate frequency, according to the diameter of shell ring, carry out corresponding induction coil (guard shield), during the flue heating, should pre-establish the process program of heating-up temperature, temperature retention time, final pressure temperature and carry out original record, having seen the following form

4.2 the flue after heating is without severe oxidation, burning, carburizing, crackle, the unequal phenomenon of heating; After air cooling, do not need annealing.

5, flue waveform spinning step

5.1 rotary press modelling signal (accompanying drawing 2)

5.2 start the lathe oil pump, start intermediate frequency power supply flue is carried out to local heat; The speed of gyration of adjusting cylindrical shell (approximately 3.5 ~ 5pm) makes the first segment wave band position local uniform of flue appointment be heated to 750 ℃ ~ 850 ℃;

5.3 movable top pinch roller 6 is to specifying first segment wave band position, make top pinch roller 6 contact cylindrical shell 3 surfaces slow feeding top pinch roller 6, general each amount of feeding continues feeding again after cylindrical shell 3 rotates a circle at 1 ~ 2mm, so spinning limit, limit heating, until waveform reaches predetermined degree of depth shape; While due to the ripple courage, being shaped, shell ring can shorten relatively, so the operator wants spinning limit, limit to tighten the adjusting nut 8 on flue tailstock 10 fixture platen axles;

5.4, after the first wave-shaped ring shapes, press the drawing inspection, after waveform meets drawing requirement, exit the top pinch roller, waveform pitch of transverse shifting top pinch roller and heater, by above-mentioned same method processing second section waveform.

Note: 1, the heating of spinning belongs to local whole circle homogeneous heating, limit heating edge spinning

2, after autoclave test, if the indices such as mechanical performance meet related standard requirements, the final pressure temperature can be relaxed to being not less than 700 ℃

3, air cooling should be waterproof, rainproof indoor carrying out.

?Power control pod with middle frequency power is that the 250KW intermediate frequency power supply uses power to be 1000Hz ~ 2500Hz

Embodiment 1: corrugated flue shell ring diameter is φ 726*8*2200mm

1. given power 120KW IF-FRE f=2500Hz heat time heating time: 8*1.5min/mm=12min heating-up temperature: 750 ℃, start spinning;

2. pinch roller jacking in top is revolved and is turned around by workpiece, and jacking 2mm, until the depth of convolution reaches drawing requirement, exits the top pinch roller;

3. after shell ring spinning part (i.e. the first node place) continues insulation 8min, move laterally to the second node place, by 1., 2. the step same method is processed next and saved waveform.

Embodiment 2: corrugated flue shell ring diameter is φ 1428*14*2200mm

1. given power 160KW IF-FRE f=2000Hz heat time heating time: 14*1.5min/mm=21min heating-up temperature: 800 ℃, start spinning;

2. pinch roller jacking in top is revolved and is turned around by workpiece, and jacking 1.5mm, until the depth of convolution reaches drawing requirement, exits the top pinch roller;

3. after shell ring spinning part (i.e. the first node place) continues insulation 14min, move laterally to the second node place, by 1., 2. the step same method is processed next and saved waveform.

Embodiment 3: corrugated flue shell ring diameter is φ 1836*18*2200mm

1. given power 220KW IF-FRE f=1000Hz heat time heating time: 18*1.5min/mm=27min heating-up temperature: 850 ℃, start spinning;

2. pinch roller jacking in top is revolved and is turned around by workpiece, and jacking 1mm, until the depth of convolution reaches drawing requirement, exits the top pinch roller;

3. after shell ring spinning part (i.e. the first node place) continues insulation 18min, move laterally to the second node place, by 1., 2. the step same method is processed next and saved waveform.

Claims (1)

1. corrugated flue spinning forming process comprises step:

1. adjust the speed of gyration 3.5 ~ 5pm of cylindrical shell, make flue 750～850 ℃ of heating wave band position local uniform heating;

2. the movable top pinch roller arrives heating wave band position, makes pinch roller contact shell ring surface, top slow feeding top pinch roller, and each amount of feeding, at 1 ~ 2mm, continues feeding again after cylindrical shell rotates a circle, and the heating of spinning limit, limit, until waveform reaches predetermined degree of depth shape; The adjusting nut on flue tailstock fixture platen axle is tightened on spinning limit, limit simultaneously;

3. after wave-shaped ring shapes, the heating wave band is continued to insulation, the time is for pressing wall thickness * min/mm; Exit the top pinch roller, waveform pitch of transverse shifting top pinch roller and heater, by 1., 2. the step same method process next the joint waveform;

It is characterized in that: described flue heater is medium frequency induction heater, and described intermediate frequency power supply uses power to be 1000Hz ~ 2500Hz, and heat time heating time is for pressing wall thickness 1.5 * min/mm.

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