CN103394575B - 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 oil burning boiler product, corrugated flue is the main pressure containing part of oil burning boiler, but manufacturing corrugated flue is the biggest problem of producing oil burning boiler.Control the Forming Quality of corrugated flue well, meeting JB/T1619-2002 " shell boiler body manufacturing technology condition " is the important step ensureing oil burning boiler quality use safety.

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

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

1. the press equipment needed is huge, and mold tooling is complicated;

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

3. owing to being that segmentation is colded pressing, through repeatedly repeatedly pressing arc, must will cause flow harden in the shaping part of cylindrical shell, having retained very large cold-working stress, so integrally annealed process must be carried out after flue cold moudling to eliminate stress.

2, rolled forming technique on three-roller type special purpose machine tool, this moulding process is not enough:

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

2. cylindrical shell spreading volume circle repeatedly, ensure barrel soldering place difficult quality, shaping rear cylinder body stress is large, palpus integrally annealed;

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

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

1. coal gas needs special gas generator, have the fireman of specialty, have larger coal piling place (coal quarrel place);

2. gas-fired is converted to by coal, higher to the quality requirement of coal, convert coal gas loss to by coal large.Hot spinning flue dust is large to ambient contamination, and operative's environment is poor;

3. heated by gas is ejected into drum surface burning, easily causes oxidation, shelling layer, have carburization phenomena time serious to cylindrical shell to drum surface.

Summary of the invention

The invention provides one and significantly can reduce wall thickness reduction amount, waveform height error and without carburization phenomena, 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 heating band po sition local uniform heating 750 ~ 850 DEG C;

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

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

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

Beneficial effect of the present invention is:

1. Frequency Induction Heating improves the quality of corrugated flue;

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

The applicant finds, heated by gas is high to drum surface heating-up temperature, and 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 pushing up pinch roller top pressure, it is inconsistent that temperature due to cylindrical shell is that ecto-entad presents a kind of step-like temperature difference, the distortion that this results in inside and outside cylindrical shell also can be inconsistent, particularly for the thick-wall cylinder of cylindrical shell thicker (as δ=18 ~ 20mm), easily cause surface to occur that spinning squeezes scar mark because surface temperature is high during spinning, affect the thick Reducing thickness of barrel, waveform height and waveform pitch.

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

2. Frequency Induction Heating does not have carburization phenomena to cylindrical shell relative to documents, and carburization phenomena mainly owing to not burning totally owing to there is coal during coal combustion, will there will be for a long time and occur carburization phenomena to drum surface between bonnet and cylindrical shell.

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;

1 medium frequency capacitor 2 upper end Medium frequency induction solenoid 3 cylindrical shell 4 intermediate-frequency transformer is identified in figure

5 lower end Medium frequency induction solenoids 6 push up pinch roller 7 chuck 8 adjusting nut 9 centering chuck

10 tailstocks.

Detailed description of the invention

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, 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 ensureing the heating effect of shell ring, and point upper end heater and lower end heater, heater coil is embedded in magnetic conductor groove, can have better heating effect;

3, mould pressing principle

Special spinning machine bed adopts heating edge feeding top, intermediate frequency power supply limit pinch roller; The curve form of top pinch roller forces cylindrical shell to heat part and is spun into corresponding curved surface;

4, flue cylindrical shell heating

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

Flue after 4.2 heating is without severe oxidation, burning, carburizing, crackle, the unequal phenomenon of heating; Annealing is not needed after air cooling.

5, flue waveform flow-forming step

5.1 rotary press modellings signal (accompanying drawing 2)

5.2 start lathe oil pump, start intermediate frequency power supply and carry out local heat to flue; The first segment band po sition local uniform that the speed of gyration (about 3.5 ~ 5pm) adjusting cylindrical shell makes flue specify is heated to 750 DEG C ~ 850 DEG C;

5.3 movable top pinch rollers 6 are to specifying first segment band po sition, top pinch roller 6 is made to contact cylindrical shell 3 surface and slow feeding top pinch roller 6, general each amount of feeding continues feeding at 1 ~ 2mm again after cylindrical shell 3 rotates a circle, and spinning limit, limit like this is heated, until waveform reaches predetermined depth shape; Due to ripple courage be shaped time, shell ring can relatively shorten, so operator wants spinning limit, limit to tighten adjusting nut 8 on flue tailstock 10 fixture platen axle;

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

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

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

3, air cooling should carry out in waterproof, rainproof indoor.

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

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

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

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

3. shell ring spinning part (i.e. the first node place) continue insulation 8min after, move laterally to the second node place, by 1., 2. step same method process next save waveform.

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

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

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

3. shell ring spinning part (i.e. the first node place) continue insulation 14min after, move laterally to the second node place, by 1., 2. step same method process next save waveform.

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

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

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

3. shell ring spinning part (i.e. the first node place) continue insulation 18min after, move laterally to the second node place, by 1., 2. step same method process next save waveform.

Claims (1)

1. a corrugated flue spinning forming process, comprises step:

1. adjust the speed of gyration 3.5 ~ 5rpm of cylindrical shell, make flue heating band po sition local uniform heating 750 ~ 850 DEG C;

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

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

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