CN102120235B - Liquid-filled pad for multipoint stretch forming - Google Patents

Abstract

The invention relates to a liquid-filled pad for multipoint stretch forming, belonging to the field of metal plastic processing. The liquid-filled pad is characterized in that: by adopting the liquid-filled pad in the multipoint stretch forming of a three-dimensional sheet piece, the surface defects of a formed piece can be suppressed, the forming quality can be improved, and the forming property of materials can be enhanced. In the multipoint stretch forming, as discrete multipoint moulds easily cause excessive local deformation and form indentation on the surface of the formed piece, the discrete mould profiles need to be serialized firstly so as to eliminate the forming defect. According to the invention, flexible materials with enough strength are made into a bag type device, and liquid is filled into the cavity of the bag type device; in the multipoint stretch forming, the liquid-filled pad is placed between the multipoint moulds and the sheet; and after the liquid flows, the liquid can be completely filled into the clearance between the punches of the basic bodies of the multipoint modules so as to form a continuous and smooth mould profile, thereby obtaining a formed piece with high quality and high precision. On the other hand, due to the existence of the liquid-filled pad, the sheet is in a hydraulic forming state during the deformation, thus the forming property of the sheet can be improved, and the forming limit can be increased.

Description

A kind of pull-shaped topping up pad of multiple spot that is used for

Technical field

The present invention relates to the pull-shaped topping up pad of using of a kind of multiple spot, be used for the stretch forming of three-dimension curved surface spare multiple spot, belong to the Metal Forming field.

Background technology

Multiple spot is pull-shaped to be a kind of flexibility, digitized three-dimension curved surface part forming technology.Adopt the pull-shaped technology of multiple spot can save a large amount of mould manufacturing expenses, realize quick shaping.Have broad application prospects in aircraft skin manufacturing field.

Though can substituting traditional unitary mould, the multiple spot mould carries out the difformity part forming; But; Because the profile of multiple spot mould is the Discrete Surfaces that is made up of the element body drift, if the multiple spot mould directly contacts with plate, element body drift contact point very easily produces excessive local deformation on drip molding; Form scraggly impression defective, have a strong impact on forming quality.In multiple spot is pull-shaped, need to use the polyurethane sheet cushion between multiple spot mould and the plate, to eliminate the influence of discrete mould point contact to drip molding.In pull-shaped process, polyurethane sheet produces the concentrated force that strain has been disperseed discrete mould point contact, obtains to suppress the effect of impression defective; But, because the solid polyurethane material flowability is limited, can only fill few part gap between the element body, the influence of discrete mould still can be delivered on the drip molding, and multiple spot is pull-shaped to be difficult to obtain more high-precision forming effect.

Summary of the invention

The present invention provides a kind of multiple spot the pull-shaped topping up pad of using; Adopt material flexible and that have a sufficient intensity to do encystation formula device; Charge into liquid in its chamber, the topping up pad is placed between multiple spot mould and the plate when multiple spot is pull-shaped, the gap between can complete filling multiple spot mould element body drift behind the liquid flow; Form smooth die face continuously, thereby obtain high-quality, high-precision forming effect.On the other hand, because the existence of topping up pad, make plate in deformation process, be in the state of hydraulic expanding-forming, help improving the formability of plate, improve forming limit.

Above-mentioned purpose of the present invention realizes that through following technical scheme accompanying drawings is following:

The pull-shaped topping up pad of using of a kind of multiple spot; Comprise topping up pad utricule 4, liquid 5, fluid flow control module 6 and fluid pressure line 7; Described topping up pad utricule 4 constitutes the airtight chamber 8 in a plurality of topping up pads by topping up pad upper surface 10 and topping up pad lower surface 11; Fill liquid 5 in the airtight chamber 8 in the topping up pad, the charging quantity of liquid 5 is by 6 controls of fluid flow control module, and topping up pad lower surface 11 is greater than topping up pad upper surface 10.

Described topping up pad lower surface 11 with the computing formula of topping up pad upper surface 10 length of side differences is:

$m(r{\sin }^{-1}\frac{a}{2r}-a),$

Wherein m is the quantity of the element body drift of length of side direction, and r is the bulb radius, and a is the length of side of element body drift side body.

Liquid carries out independent control in the airtight chamber 8 in 6 pairs of each topping up pads of described each fluid flow control module, by the flow of required discharge liquid, the volume of liquid with precise control.The topping up pad is full of liquid before use; In use need discharge certain amount of fluid; Liquid to guarantee the topping up pad is filled the gap between the multiple spot mould punch body 9 smoothly; And guarantee that topping up pad upper surface is consistent with multiple spot mould enveloping surface, the volume of required discharge liquid should confirm that the computing formula that each chamber need be discharged liquid volume is according to the shape and the multiple spot die parameters of drip molding:

$\mathrm{mn\&pi;}(r^2-\frac{{\mathrm{<figure-callout\; id="2"\; label="a"\; filenames="HDA0000038092660000011.png"\; state="\{\{state\}\}">a</figure-callout>}}^2}{4})(r-\frac{1}{3}\sqrt{r^2-\frac{a^2}{4}})$

Wherein m is the element body number that topping up pad width comprises, the element body number that n comprises for the chamber width direction, and r is an element body bulb radius, a is the length of side of element body drift side body.

The liquid 5 that charges in the airtight chamber 8 in the described topping up pad is water or oil or other liquid.

Technique effect: the present invention is used for that three-dimensional sheet member multiple spot is pull-shaped can to suppress the drip molding blemish, improves forming quality, and can improve the formability of material.In multiple spot was pull-shaped, discrete multiple spot mould very easily caused excessive local deformation, formed impression on the drip molding surface, must at first make discrete die face serialization for eliminating forming defects.The material that the present invention adopts flexibility and has a sufficient intensity is done encystation formula device; Charge into liquid in its chamber; The topping up pad is placed between multiple spot mould and the plate when multiple spot is pull-shaped; Can complete filling arrive the gap between the multiple spot mould element body drift behind the liquid flow, form smooth die face continuously, thereby obtain high-quality, high-precision drip molding.On the other hand, because the existence of topping up pad, make plate in deformation process, be in the state of hydroforming, can improve the formability of plate, improve forming limit.

Description of drawings

Fig. 1 is to use the pull-shaped sketch map of the multiple spot of topping up pad;

Fig. 2 a is the section of structure of topping up pad;

Fig. 2 b is the structural representation of topping up pad;

Fig. 3 is the calculation specifications sketch map that each chamber need be discharged liquid volume.

Among the figure: 1. topping up pad, the 2. pull-shaped mould of multiple spot, 3. plate, 4. topping up pad utricule, 5. liquid, 6. fluid flow control module, 7. fluid pressure line, the 8. airtight chamber in the topping up pad, 9. element body drift, 10. topping up pad upper surface, 11. topping up pad lower surfaces

The specific embodiment

Further specify the particular content of the present invention and the course of work thereof below in conjunction with the accompanying drawing illustrated embodiment.

A kind of multiple spot of the present invention is pull-shaped with topping up pad 1; When multiple spot is pull-shaped, be placed between multiple spot mould 2 and the plate 3; Comprise topping up pad utricule 4, liquid 5, fluid flow control module 6, fluid pressure line 7, the volume of liquid can accurately be controlled through flow controlling unit 7 in the described topping up pad 1, through the discharge of fluid is set; The liquid that can guarantee topping up pad in multi-point forming is fully filled the gap between the multiple spot mould punch body 2; Form smooth multiple spot die face continuously, and make plate in deformation process, be in the state of hydroforming, obtain high-quality, high-precision forming effect.

Described multiple spot is pull-shaped thinner with topping up pad utricule 4 wall thickness, has flexibility and sufficient intensity is arranged, and can be processed by nylon or other composite; The liquid that charges in the described topping up pad chamber can be water, oil or other liquid, has good flowability, can fill the gap between the multiple spot mold and punching head 9, suppresses blemish; The inner chamber of whole topping up pad is separated into some independent sealed chambers 8 and flows to the edge in case the solution stopping body is concentrated, and guarantees that the liquid in each chamber can fully be filled the gap between the element body drift 9 that is covered; The size of topping up pad lower surface 11 is slightly larger than upper surface 10, is coated on multiple spot mould punch body 9 surfaces fully to guarantee it, and its difference in areas is confirmed by the size and the quantity of element body 9.Pull-shaped process finishes back topping up pad and returns to the initial natural state, can use repeatedly.

Described multiple spot is pull-shaped need to be full of liquid before use with the topping up pad; In pull-shaped process, discharge certain amount of fluid gradually; Make the liquid of topping up pad fill the gap between the multiple spot mould punch body 9 smoothly, thereby the upper surface 10 that guarantees the topping up pad form and the consistent profile of multiple spot mould enveloping surface.The volume of required discharge liquid should be confirmed according to the shape of drip molding and the size and the quantity of multiple spot mould.

Described flow controlling unit 6 can carry out independent control to liquid in each chamber 8 of topping up pad, and by the volume that the liquid amount of charging into and the discharge of setting are accurately controlled liquid in the chamber 8, liquid flows into, flows out through fluid pressure line 7.

Fig. 1 is to use the pull-shaped sketch map of the multiple spot of topping up pad.Be full of liquid in the topping up pad 1 during beginning, be placed between multiple spot mould 2 and the plate 3.Liquid in the forming process in the topping up pad 1 is filled the gap between the element body drift 9, and the lower surface 11 of topping up pad coats on the element body drift 9, and upper surface 10 forms the continuous smooth profile consistent with multiple spot mould enveloping surface and is used for sheet forming.

Fig. 2 is the structural representation of topping up pad.Topping up pad 1 is made up of utricule 4, liquid 5, fluid flow control module 6, fluid pressure line 7 etc.; Its whole inner chamber is separated into some independent sealed chambers 8 and flows to the edge in case the solution stopping body is concentrated.The interior liquid of topping up pad flows into, flows out through fluid pressure line 7, and the volume of inflow in each chamber 8, trickle is respectively by flow controlling unit 6 controls.Lower surface 11 sizes of topping up pad fully are coated on the element body drift 9 in the pull-shaped process of multiple spot to guarantee it greater than upper surface 10, and the computing formula of its lower surface and upper surface length of side difference is:

$m(r{\sin }^{-1}\frac{a}{2r}-a)$

Wherein m is the quantity of the element body drift of length of side direction, and r is the bulb radius, and a is the length of side of element body drift side body.

The topping up pad is full of liquid before use, in use need discharge certain amount of fluid, fills the gap between the multiple spot mould punch body 9 smoothly with the liquid that guarantees the topping up pad, and guarantees that topping up pad upper surface is consistent with multiple spot mould enveloping surface.The volume of required discharge liquid should confirm that with reference to Fig. 3, the computing formula that each chamber need be discharged liquid volume is according to the shape and the multiple spot die parameters of drip molding:

$\mathrm{mn\&pi;}(r^2-\frac{{\mathrm{<figure-callout\; id="2"\; label="a"\; filenames="HDA0000038092660000011.png"\; state="\{\{state\}\}">a</figure-callout>}}^2}{4})(r-\frac{1}{3}\sqrt{r^2-\frac{a^2}{4}})$

Wherein m is the element body number that topping up pad width comprises, the element body number that n comprises for the chamber width direction, and r is an element body bulb radius, a is the length of side of element body drift side body.

Claims (3)

1. pull-shaped topping up pad of using of multiple spot; Comprise topping up pad utricule (4), liquid (5), fluid flow control module (6) and fluid pressure line (7); Described topping up pad utricule (4) constitutes the airtight chamber (8) in a plurality of topping up pads by topping up pad upper surface (10) and topping up pad lower surface (11); The interior fill liquid of airtight chamber (8) (5) in the topping up pad; The charging quantity of liquid (5) is controlled by fluid flow control module (6); Topping up pad lower surface (11) is characterized in that greater than topping up pad upper surface (10) described topping up pad lower surface (11) with the computing formula of topping up pad upper surface (10) length of side difference is:

wherein m is the quantity of the element body drift (9) of length of side direction; R is an element body bulb radius, and a is the length of side of element body drift (9).

2. the pull-shaped topping up pad of using of a kind of multiple spot according to claim 1; It is characterized in that; Described each fluid flow control module (6) carries out independent control to the interior liquid of airtight chamber (8) in each topping up pad, by the flow of required discharge liquid, and the volume of control liquid; The topping up pad is full of liquid before use; In use need discharge certain amount of fluid, fill the gap between the multiple spot mould element body drift (9) smoothly, and guarantee that topping up pad upper surface is consistent with multiple spot mould enveloping surface with the liquid that guarantees the topping up pad; The volume of required discharge liquid should confirm that the computing formula that each chamber need be discharged liquid volume is according to the shape and the multiple spot die parameters of drip molding:

wherein m is element body drift (9) number that topping up pad width comprises; Element body drift (9) number that n comprises for the chamber width direction; R is an element body bulb radius, and a is the length of side of element body drift (9).

3. the pull-shaped topping up pad of using of a kind of multiple spot according to claim 1 is characterized in that, the liquid (5) that charges in the airtight chamber (8) in the described topping up pad is water or oil or other liquid.

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