CN86107752A - Aperture mask lateral margin draw forming method and products thereof - Google Patents

Abstract

Utilize drawing work to draw the lateral margin of shadow mask, this shadow mask plate 1 that is used for color picture tube is made of invar sections nickel alloy.In described pulling process, make and form lateral margin 22 on the shadow mask plate 1.In pulling process, the limit 16 of lateral margin 22 is clamped in anti-skidding mode, so that lateral margin 22 can be by plastic deformation in its formation, the result has improved the reproducibility of shadow mask plate 1 shape.

Description

The present invention relates to utilize drawing work to draw the method for shadow mask lateral margin, the shadow mask plate that is used for color picture tube generally is made of invar sections nickel alloy, processes lateral margin with this method on the shadow mask plate.

In addition, the present invention is relevant with the shadow mask made from this method.

The present invention is also relevant with the color picture tube that includes this shadow mask.

A kind of method so formerly proposed in the Netherlands patent applications 8402958, had described the technical process of drawing the shadow mask plate lateral margin that is made of iron-nickel alloy in this application.In the former actual drawing process, the shadow mask plate will be through Overheating Treatment, so that the material of shadow mask plate produces crystallization more completely under the situation that grain growth does not take place, and reduce tensile stress on 0.2% proof stress, this tensile stress is concerning at room temperature being drawn into the shadow mask plate the required form, and is just too big.But, when drawing the technology reproduced of lateral margin, must further reduce tensile stress for obtaining the shadow mask plate.In order to reach this purpose, the shadow mask plate draw the course of processing, be not to be in room temperature, get off to carry out but be in high temperature.In this process of drawing shadow mask plate lateral margin, generally at first make it reach required shape, this is actually an arc, reprocesses lateral margin subsequently.This lateral margin is that the whole edge by crooked shadow mask forms, and this lateral margin can be used to shadow mask is connected in the color picture tube.After forming lateral margin, drawing work promptly comes to an end, and shadow mask is cooled to ambient temperature, and material turns back to the tensile stress reset condition of a little higher than 0.2% proof stress substantially.

Have now found that because the tensile stress of this a little higher than 0.2% proof stress makes lateral margin produce outside a little resilience, this can have a negative impact to the shape of shadow mask plate.And the shadow mask of moulding is normally linked on the stand frame by a large amount of spot welding between stand frame and the lateral margin, yet outwards the lateral margin of resilience can not make itself and stand frame engage fully, therefore shadow mask is being soldered to some problems of existence in the support process.

The purpose of this invention is to provide a kind of method of drawing the shadow mask lateral margin that is made of invar sections nickel alloy, this method can make the shape of shadow mask plate obtain reproducibility preferably.

In the method for purpose described in the opening paragraph, be characterised in that with the formation of lateral margin complementaryly mutually according to the present invention, described lateral margin is plastic deformation for good and all.Have now found that the result of this permanent plastic deformation is controlled the shape of lateral margin and position fully.And the result that the outside resilience scope of lateral margin reduces has obtained shadow mask plate shape reproducibility preferably.Bonus of the present invention is that lateral margin can engage fully with stand frame, thereby can make that lateral margin is easier to be soldered on the described stand frame.

According to an embodiment of the inventive method, be characterised in that the permanent plastic deformation of lateral margin occurs between 150 ℃ and 250 ℃ of the temperature, when plastic deformation is when at room temperature carrying out, the tensile stress of a little higher than 0.2% proof stress causes the difficulty of material mechanical processing.When plastic deformation is that the shadow mask material can reduce at the tensile stress of 0.2% proof stress when carrying out between 150 ℃ and 250 ℃ of the temperature.The result increases the machinability of material, thereby can satisfy the reproducibility requirement of drawing work.

According to another embodiment of the inventive method, the plastic deformation that is characterised in that lateral margin is being that formation with lateral margin is simultaneous at least haply; And on described lateral margin, form a flange.Lateral margin forms on the shadow mask plate by drawing operation.The plastic deformation of described lateral margin has comprised the auxiliary operation of carrying out repeatedly.In drawing process, clamp the edge of shadow mask in anti-skidding mode, so the shaping of lateral margin and plastic deformation can be carried out simultaneously.According to the present invention, owing to no longer need to be used as the additional operations of deformation, thereby saved the time.In addition, because the drawing work of shadow mask plate can be carried out between 150 ℃ and 250 ℃ of temperature, the additional heating that therefore is used for the plastic deformation of shadow mask plate lateral margin also no longer needs.

Another embodiment according to the inventive method is characterised in that, before the flange recess on the shadow mask plate forms, forms described recess at least on the major part of the part that constitutes flange thereafter of shadow mask plate.If the shadow mask plate is connected on the stand frame, for example by spot welding, then welding equipment must contact with lateral margin.Therefore outside flange can counteract.By must provide recess in order to the part of spot welding on flange, then welding equipment can the contact side edge on these ground.Drawing first being processed, can on the shadow mask plate, form described recess, (for example, adopt with on the shadow mask plate, form cover the identical corrosion-tank finishing process in hole) by corrosion-tank finishing process.But it also is possible processing recess again after flange forms, and for example, cut away the part flange material, but this will expend time in.

Now with reference to accompanying drawing one embodiment of the present of invention are described in more detail, these accompanying drawings are:

Fig. 1 shows in drawing process, through the tensile stress of heat treated invar sections nickel alloy curve as a function of temperature,

Fig. 2 to 8 shows each step of this method,

Fig. 9 shows a shadow mask of being made by described method.

Figure 10 is the shadow mask sectional view that is connected to stand frame.

By nickel content is the shadow mask plate that the invar sections nickel alloy of weight 35-37% constitutes, carrying out the actual first being processed of drawing, will be through Overheating Treatment, for example, handle a period of time between 700 ℃ and 820 ℃ of temperature, this time will be enough to make the shadow mask material to produce crystallization more completely under the situation that grain growth does not take place.The result is reduced the tensile stress of material on 0.2% proof stress, still, reaches 0.2% proof stress, and is still too high for the reproducibility that will obtain the shadow mask lateral margin is drawn processing.For this reason, be necessary further to reduce the tensile stress of 0.2% proof stress.In order to realize this target, the shadow mask plate is not at room temperature but draw lateral margin between 150 ℃ and 250 ℃ of temperature.Fig. 1 shows tensile stress under 0.2% proof stress as the change curve of temperature funtion.In 150 ℃ to 250 ℃ temperature ranges, the tensile stress on 0.2% proof stress relevant with temperature raises and significantly decline with temperature.Temperature still can obtain slightly little decline more than 250 ℃ the time.But, under such high temperature, on 0.2% proof stress problem of the actual generation of the reduction of tensile stress and drawing work by comparison, with regard to few of advantage.

Fig. 2. be the equipment schematic cross-section that is used for drawing shadow mask plate 1 lateral margin.This equipment comprises that a drawing-die 2(is called " core bar " sometimes), a pressure ring 3(is called " ruffle carriage " sometimes) and a bail 4.Shadow mask plate 1 is placed on the drawing die 2.Bail 4 descends towards pressure ring 3 then, so that the edge of shadow mask plate 1 is clamped at (see figure 3) between the bail 4 of opposite side and the pressure ring 3 in anti-skidding mode.As shown in Figure 4, the actual lateral margin of shadow mask plate 1 draws when bail 4 and pressure ring 3 descend simultaneously and takes place.Shadow mask plate 1 draws on drawing-die 2 then.In this process, the temperature of shadow mask plate 1 is adjusted between 150 ℃ and 250 ℃.For this purpose, drawing-die 2 comprises the copper billet 5 that is embedded with electrical heating elements 6, and similarly, pressure ring 3 comprises the copper billet 7 and the bail 4 that have heating element 8 and comprises the copper billet 9 that has heating element 10.The drawing work that shadow mask plate 1 can heated is heated between 150 ℃ and 250 ℃.But, also passable with another kind of method shadow mask plate 1, be heating in advance in the heating furnace of 150 ℃ and 250 ℃ in temperature.In order to make the uniformity of temperature profile of whole shadow mask plate in drawing process, drawing-die 2 includes a large amount of heat pipes 11, and these heat pipes are guaranteed the surface temperature unanimity of drawing-die 2.After shadow mask plate 1 has drawn lateral margin, make its edge form a flange by crooked its peripheral part.For this reason, pressure ring 3 is by downwards up to freely being pressed in (see figure 5) on the spring 12.Thereafter, the edge of shadow mask plate 1 no longer is clamped between pressure ring 3 and the bail 4, and is clamped between ejector 13 and the drawing-die 2.Ejector 13 includes the copper billet 14 of being with heating element 15 equally, so that the ejector 13 that contacts with shadow mask plate 1 also is heated between 150 ℃ and 250 ℃.Then, bail 4 is further descended, so that the limit 16 of lateral margin 22 is clamped between bail 4 and the pressure ring 3 (Fig. 6).Then, pressure ring 3 and bail 4 pressuring springs 12 are through one section distance that is easy to determine, and the limit 16 of lateral margin 22 is still clamped.Thereby lateral margin is stretched and produce plastic deformation.Spring 12 is located immediately between bail 4 and the pressure ring 3, the below on the surface of clamping shadow mask plate.The number of spring 12 is through selecting, so that the pressure of bail 4 evenly distributes between described spring 12.When lateral margin 22 was shaped, the backside pressure that is provided by spring 12 equaled the downward pressure of pressure ring 3 and bail 4.Limit 16 must be enough wide, clamps securely guaranteeing.Spring 12 is owing to (Fig. 7) loosened in the rising of ejector 13.After lateral margin 22 was shaped, bail 4 lifted, and shadow mask 1 rises thereupon.At last, shadow mask 1 is by ejector 13(Fig. 8) be pushed out and unload from bail 4.If shadow mask 1 is promptly removed from drawing-die 2, will produce distortion, this is because shadow mask is heated.In order to prevent distortion, when still being clamped between pressure ring 3 and the bail 4, shadow mask is lifted at leisure on the position of certain distance above the drawing-die 2 by lever system 17.So just, can reduce the possibility of shadow mask 1 distortion.Lever system 17 can be operated by for example compressed air.After shadow mask 1 has been risen to drawing-die 2 positions recited above lentamente, further fast rise just.

It should be noted, be used for bail 4, the operating mechanism of pressure ring 3 and ejector 13 does not all draw in the accompanying drawings, because these parts and the present invention do not have direct relation.

Make the possibility of its plastic deformation except existing when lateral margin 22 forms basically, even after drawing work is finished, because the plastic deformation when forming flange 18, lateral margin 22 yet might plastic deformation.This can carry out under its room temperature, but in this case because the tensile stress of a little higher than 0.2% proof stress is an impediment to machining.When described plastic deformation is that the tensile stress under 0.2% proof stress can further reduce, thereby has improved machining property when carrying out between 150 ℃ and 250 ℃ of the temperature.

As mentioned above, the shape that is added on the lateral margin 22 by plastic deformation need not be confined to export-oriented flange 18.After drawing work finished, the plastic deformation of lateral margin 22 can in all sorts of ways and realize.But, if require the plastic deformation of lateral margin 22 and the shaping of lateral margin 22 to realize simultaneously that basically according to embodiments of the invention, the generation of described plastic deformation is only limited to outside flange 18.

Shadow mask 1 according to the inventive method manufacturing is shown in Fig. 9.As the result who in forming lateral margin 22 processes of shadow mask 1, produces permanent plastic deformation, the shape of shadow mask 1 is become repeat processing easily.When the optimised form that adopts according to the inventive method, on lateral margin 22, form an outside flange 18 simultaneously.The width of flange 18 is corresponding to the width on limit 16, and this limit finishes to be clamped between bail 4 and the pressure ring 3 up to drawing work always.Just as has been said, limit 16 must be enough wide, guaranteeing to have clamping preferably, thereby must make the shape of shadow mask 1 repeat processing easily.On the other hand, also should not do flange 18 too widely, because just need excessive material like this.The width of flange 18 is preferably between 1 and 5 millimeter.

If wish as shown in figure 10 shadow mask 1 to be fixed on the stand frame 19, for example use spot welding, outside flange 18 has just become a kind of obstacle.Than advantageous method is to form several recesses 20 on the limit of shadow mask plate 1, for example, and the recess of etching simultaneously during etching cover hole 21.Then because these appear at recess 20 on the flange 18 drawing work after, make when welding, welding equipment reaches on the lateral margin 22 of shadow mask 1 in recess 20 zones with just having no obstacle.The width of recess 20 will be suitable for the width of spot-welding equipment.Wide recess during lateral margin 22 forms, can cause that tensile stress variations appears in the lateral margin 22 of the shadow mask 1 on the recess extended line and lateral margin 22 parts between each recess 20.This will have a negative impact to the shape of shadow mask 1.The width of recess 20 is preferably between 16 and 16 millimeters.When selecting the degree of depth of recess 20, same, play two reasons of effect in the time of should considering above-mentioned selection recess 20 width.The degree of depth of recess 20 preferably equals the width of flange at least substantially.

Claims (7)

1, utilize drawing work to draw the method for shadow mask lateral margin, this method forms lateral margin on the shadow mask plate that is used for color picture tube that is made of invar sections nickel alloy, it is characterized in that, complementary mutually with the formation of lateral margin, and described lateral margin is by plastic deformation for good and all.

2, according to the desired method of claim 1, the permanent plastic deformation that is characterised in that lateral margin realizes between 150 ℃ and 250 ℃ of temperature.

3, according to claim 1 or 2 desired methods, the plastic deformation that is characterised in that lateral margin is simultaneous with the formation of lateral margin at least substantially; And on described lateral margin, be formed with flange.

4, according to the desired method of claim 3, be characterised in that, before forming the flange recess on the shadow mask plate, on the major part of that part of shadow mask plate that constitutes flange thereafter, form described recess at least.

5, according to the desired method of arbitrary claim as described above, be characterised in that selecting nickel content for use is the invar class iron-nickel alloy of the 35-37% of weight.

6, a kind of shadow mask is characterized in that being making with the desired method of above-mentioned arbitrary claim.

7, a kind of color picture tube is characterised in that to include the desired shadow mask of claim 5.

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