CN114904969A - Automobile body covering part drawing die and design method of residual meat male die thereof - Google Patents

Abstract

The invention discloses a design method of a drawing die of a vehicle body covering part and a residual meat convex die of the drawing die, belonging to the technical field of dies and comprising an upper base plate, a lower base plate, a drawing concave die, a drawing convex die, a lower pressing ring, a residual meat convex die and a guide plate; the residual meat male die is positioned inside the drawing male die, and the drawing male die and the residual meat male die are connected in a vertically sliding fit manner through a guide plate; the lower material pressing ring is connected with the lower bottom plate through a guide plate in a vertically sliding fit manner. When the material is pressed by the pressing ring, the residual meat convex die with controllable stroke is ejected out, the sheet material firstly contacts the residual meat convex die and then contacts the ridge line of the rear wheel cover, and the sliding of the ridge line is reduced; before the drawing female die is contacted with the residual meat male die, the residual meat male die starts to move downwards, the residual meat male die is not contacted with the drawing female die, and does not participate in forming in the forming process; after the forming process is finished, the residual meat male die is completely hidden in the drawing male die, and the application of the drawing die is favorable for perfectly showing the artistic modeling effect of the automobile body and improving the drawing forming quality of the automobile body covering part.

Description

Design method of vehicle body covering part drawing die and residual meat male die thereof

Technical Field

The invention belongs to the technical field of dies, and particularly relates to a drawing die for a car body covering part and a design method of a residual meat convex die of the drawing die.

Background

In the automobile outer covering part, the integral side wall is one of key parts in the automobile body outer covering part, the structural size of the integral side wall is the largest one in the covering parts, the part has complicated geometric shape and extremely high requirements on surface quality and dimensional precision, and as a welding reference of the whole automobile, the integral side wall has very complicated matching relation and has strict matching relation with main parts such as a fender, a top cover, a trunk, a wheel cover, a floor side beam, front and rear doors and the like. In summary, in order to realize the design intention of the product shape, research must be carried out on the forming process to realize the modeling characteristics of the part and ensure the forming quality of the product in the forming process of each working procedure of the stamping die; therefore, it is necessary to study the forming properties of the appearance ridge and surface quality of the part, and to control the forming properties layer by layer so as to realize sharp product shape characteristics.

Disclosure of Invention

In order to overcome the defect of surface quality of an automobile body covering part in the conventional drawing forming process method, the invention aims to provide a drawing die for the automobile body covering part and a design method for a residual meat convex die of the drawing die, wherein when a material pressing ring presses the material, the stroke of the drawing die is controllable, the residual meat convex die is ejected out, a plate material firstly contacts the residual meat convex die and then contacts a ridge line of a rear wheel cover, so that the slippage of the ridge line is reduced; before the drawing female die is contacted with the residual meat male die, the residual meat male die starts to move downwards, the residual meat male die is not contacted with the drawing female die, and does not participate in forming in the forming process; after the forming process is finished, the residual meat male die is completely hidden in the drawing male die, and the application of the drawing die is favorable for perfectly showing the artistic modeling effect of the automobile body and improving the drawing forming quality of the automobile body covering part.

The invention is realized by the following technical scheme:

a drawing die for a vehicle body covering part comprises an upper base plate 1, a lower base plate 2, a drawing female die 3, a drawing male die 4, a lower pressing ring 6, a residual meat male die 5 and a guide plate 8; the drawing female die 3 is arranged on the upper base plate 1, the drawing male die 4 is arranged on the lower base plate 2, the residual meat male die 5 is positioned inside the drawing male die 4, and the drawing male die 4 and the residual meat male die 5 are connected in a vertically sliding fit manner through a guide plate 8; the lower material pressing ring 6 is connected with the lower bottom plate 2 in a vertically sliding fit manner through a guide plate 8; an elastic element 9 is arranged above the air cushion support rod under the press machine, and the elastic element 9 is fastened on the residual meat convex die 5.

Further, the upper base plate 1 is connected with an upper sliding block of the press machine through a press machine quick clamping mechanism, and the lower base plate 2 is fixed with a press machine workbench through a press plate fastening bolt.

Furthermore, the drawing convex die 4 is provided with a limiting block 7 for limiting the residual meat convex die 5 when the residual meat convex die 5 moves upwards.

Further, guide plates 8 are arranged on the lower material pressing ring 6, the drawing convex die 4 and the residual meat convex die 5, and the guide plates 8 have a guiding function.

Further, the elastic element is a nitrogen spring.

On the other hand, the invention also provides a design method of the residual meat convex die of the vehicle body covering part drawing die, which comprises the following steps:

step one, preparation of CAE analysis: loading the part curved surface data into plate forming simulation analysis software to complete the preparation of plate parameters;

step two, confirming the stamping direction: determining the drawing and stamping direction of the part according to the main ridge;

step three, supplementing the internal process of the part: filling the inner cavity of the part curved surface by adopting curved surface modeling software;

step four, supplement of the pressed noodles: adopting an offset curve method for the concave curve boundary of the part adapting to the shape of the wheel to supplement the pressing surface, and then performing process supplement on the part between the two curves;

step five, carrying out simulation analysis on the generated die surface of the female die;

sixthly, determining the position and the style of the residual meat;

and step seven, designing a die for the generated die surface of the part drawing process.

Further, the sixth step is as follows:

s61: determining the position and the style of the residual meat according to the slip lines of the CAE analysis result, and performing CAE analysis again after adding corresponding residual meat at the required position;

s62: after adding the residual meat, if the slip lines at the edge lines of the wheel cover are eliminated, the CAE analysis result is ended; if the cracking phenomenon is not eliminated, the process goes to S63;

s63: continuously adjusting the position and height of the residual meat, and setting the action stroke of the residual meat if the cracking phenomenon cannot be eliminated;

s64: and adjusting the stroke of the residual meat according to the CAE analysis result, thereby eliminating slippage and cracking.

Further, the seventh step is as follows:

s71: the die structure is designed according to the drawing form of the common side wall outer plate, and the residual meat needs to be designed into a residual meat convex die with controllable stroke;

s72: determining the force and the stroke of a nitrogen spring of the residual meat male die according to the stroke and the forming force of the residual meat obtained from the CAE analysis result;

s73: the supporting rod is used for jacking and compressing the nitrogen spring, the stroke of the nitrogen spring is released along with the reduction of the supporting rod, and after the stroke of the nitrogen spring is completely released, the residual meat convex die continuously descends along with the supporting rod, so that the stroke controllability is realized.

Further, the evaluation rule of the CAE analysis result is as follows:

(1) the thinning rate index range is 3% -20%;

(2) failure index < 0.75;

(3) the wrinkling index is less than 0.03;

(4) the sliding of the ridge does not exceed the R area of the product;

(5) the main strain index is more than 0.02, and the secondary strain index is more than or equal to 0;

(6) and the distance between the impact line of the concave die fillet of the outer surface part and the visible surface of the product is more than 5 mm.

Compared with the prior art, the invention has the following advantages:

according to the design method of the drawing die for the automobile body covering part and the residual meat convex die, the residual meat of the convex die with the controllable stroke is added in the drawing convex die, the height of the residual meat is ensured at the initial stage when the residual meat is needed, the product is prevented from generating wrinkles, but the residual meat can be eliminated at the later stage of forming, and the product is prevented from cracking.

Drawings

In order to more clearly illustrate the detailed description of the invention or the technical solutions in the prior art, the drawings that are needed in the detailed description of the invention or the prior art will be briefly described below. Throughout the drawings, like elements or portions are generally identified by like reference numerals. In the drawings, elements or portions are not necessarily drawn to scale.

FIG. 1 is a drawing nip start state sectional view;

FIG. 2 is a section of the punch for meat at the highest state;

FIG. 3 is a drawing completion state sectional view;

FIG. 4 is a drawing die in general schematic view;

FIG. 5 is a schematic cross-sectional view of the initial position of the residual meat punch;

FIG. 6 is a schematic cross-sectional view of the bottom position of the meat punch;

FIG. 7 is a schematic flow diagram of a method of designing a residual meat punch;

in the figure: the device comprises an upper base plate 1, a lower base plate 2, a drawing female die 3, a drawing male die 4, a residual meat male die 5, a lower pressing ring 6, a limiting block 7, a guide plate 8 and a nitrogen spring 9.

Detailed Description

For clearly and completely describing the technical scheme and the specific working process thereof, the specific implementation mode of the invention is as follows by combining the attached drawings of the specification:

in the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Example 1

The embodiment provides a drawing die for a vehicle body covering part, which is characterized in that in the CAE (sheet metal forming) process of sheet material forming, a residual meat convex die is additionally arranged, the residual meat convex die is fixed and does not move in the front half section (the length of the residual meat convex die can be set) of the drawing full stroke, the residual meat convex die and the sheet material react, and the residual meat convex die and the sheet material react while the rear half section of the drawing full stroke and an upper die synchronously descend, so that the high-quality vehicle body covering part is obtained.

As shown in fig. 5 and 6, the drawing die for the vehicle body covering part of the present embodiment includes a drawing female die, a drawing male die, a lower blanking ring, and a residual meat male die, wherein the drawing male die is mounted on a lower base plate, and the lower blanking ring, the lower base plate, and the drawing male die are guided inside and outside by guide plates. The residual meat male die moves in the male die by a guide plate, the power source of the residual meat male die is a nitrogen spring, and a limiting block limits the stroke of the residual meat male die after the residual meat male die is in place. The drawing concave die is arranged on the upper base plate.

When the lower pressing ring presses materials, the residual meat convex die with the controllable stroke is ejected out, the plate firstly contacts with the residual meat convex die with the controllable stroke and then contacts with the ridge line of the rear wheel cover, and the sliding of the ridge line is reduced; before the drawing female die is contacted with the residual meat male die with the controllable stroke, the residual meat male die starts to move downwards, the residual meat male die is not contacted with the drawing female die, and the residual meat male die does not participate in forming in the forming process; and (5) finishing the forming process, and completely hiding the residual meat male die with the controllable stroke in the drawing male die.

Example 2

As shown in fig. 5, the embodiment provides a drawing die for a vehicle body covering part, which comprises an upper base plate 1, a lower base plate 2, a drawing female die 3, a drawing male die 4, a lower blanking ring 6, a residual meat male die 5 and a guide plate 8; the drawing female die 3 is arranged on the upper base plate 1, the drawing male die 4 is arranged on the lower base plate 2, the residual meat male die 5 is positioned inside the drawing male die 4, and the drawing male die 4 and the residual meat male die 5 are connected in a vertically sliding fit manner through a guide plate 8; the lower material pressing ring 6 is connected with the lower bottom plate 2 in a vertically sliding fit manner through a guide plate 8; an elastic element 9 is arranged above the air cushion support rod under the press machine, and the elastic element 9 is fastened on the residual meat convex die 5.

The upper base plate 1 is connected with an upper sliding block of the press machine through a press machine quick clamping mechanism, and the lower base plate 2 is fixed with a press machine workbench through a press plate fastening bolt.

And the drawing convex die 4 is provided with a limiting block 7 for limiting the residual meat convex die 5 when the residual meat convex die 5 moves upwards.

And guide plates 8 are arranged on the lower material pressing ring 6, the drawing male die 4 and the residual meat male die 5, and the guide plates 8 have a guiding function.

The elastic element is a nitrogen spring.

The working process of the drawing die for the automobile body covering part comprises the following steps:

when the die is opened, the lower air cushion support rod is ejected out, the structure surface of the residual meat male die in the lifted state is tightly attached to the upper limiting surface of the lower male die, and the elastic element is compressed between the lower air cushion support rod and the structure surface of the residual meat male die; the upper drawing female die descends in the die closing process, the plate is pressed by the upper drawing female die and the drawing material pressing ring and pushes the drawing material pressing ring to move downwards together with the upper drawing female die, the plate is gradually formed under the action of the drawing male die and the upper drawing female die, and the residual meat male die (in an ejection state under the action of the elastic pressure of the built-in nitrogen spring) plays a role in supporting the plate in the process, so that the plate is prevented from sliding on the ridge line of the drawing male die to form visible appearance defects; the stroke of downward movement of the drawing material pressing ring pushed by the downward movement of the upper drawing female die exceeds the compression amount of the built-in nitrogen spring, the residual meat male die without elastic pressure support starts to descend synchronously with the upper drawing female die under the action of gravity and plate pressure, and the effect is to reduce the cross section length of the male die and avoid the plate (exceeding the elongation rate limit) from cracking.

According to the drawing die for the automobile body covering part, when a material is pressed by the material pressing ring, the stroke-controllable residual meat male die is ejected out, a plate material firstly contacts the stroke-controllable residual meat male die and then contacts a ridge line of a rear wheel cover, and the sliding of the ridge line is reduced; before the female die is contacted with the stroke-controllable residual meat male die, the stroke-controllable residual meat male die starts to move downwards, the stroke-controllable residual meat male die is not contacted with the female die, and the residual meat male die does not participate in forming in the forming process; and after the forming process is finished, the stroke-controllable residual meat male die is completely hidden in the male die.

As shown in fig. 1, which is a drawing attached to a drawing start state section, a lower material pressing ring of a drawing female die just presses materials, and a residual meat male die ejects out of a drawing male die;

as shown in fig. 2, the section of the residual meat convex die in the highest state is shown in the attached drawing, and the residual meat convex die plays a role of residual meat and solves the problem of slippage of the edge line of the side wall rear wheel cover;

as shown in fig. 3, the drawing is completed and the molding process is completed, the residual meat convex mold is completely hidden in the convex mold and does not participate in molding, so that the difficulty of material transportation caused by residual meat molding is avoided, and the edge line of the rear wheel cover slides to the residual meat side to increase the sliding line;

as shown in fig. 4, which is a schematic structural diagram of a drawing die, a drawing female die is connected with an upper sliding block of a press machine through a press machine quick clamping mechanism; the drawing male die is fixed with a press workbench through a pressure plate fastening bolt;

as shown in fig. 5, which is a schematic view of a section of an initial position of a residual meat punch, when a material pressing ring is jacked up, a supporting rod is jacked out, the residual meat punch is limited by a punch body, the stroke of a nitrogen spring is compressed, and the jacked-up height of the residual meat is a theoretical height obtained from a CAE analysis result;

as shown in fig. 6, which is a schematic cross-sectional view of the punch from the rest meat to the bottom, the press support rod is compressed as the female die drives the material pressing ring to move downward, the stroke of the nitrogen spring of the punch is gradually released, and when the stroke of the nitrogen spring is completely released, the punch continues to move downward along with the support rod until the punch is completely hidden in the punch.

Example 3

As shown in fig. 7, a flow chart of a method for designing a residual meat convex die is provided, and the embodiment further provides a method for designing a residual meat convex die of a drawing die for a vehicle body covering part, which specifically includes the following steps:

step one, preparation of CAE analysis: loading the part curved surface data into plate forming simulation analysis software to complete the preparation of plate parameters;

step two, confirming the stamping direction: determining the drawing and stamping direction of the part according to the main ridge;

step three, supplementing the internal process of the part: filling the inner cavity of the part curved surface by adopting curved surface modeling software;

step four, supplement of the pressed noodles: adopting an offset curve method for the concave curve boundary of the part adapting to the shape of the wheel to supplement the pressing surface, and then performing process supplement on the part between the two curves;

step five, carrying out simulation analysis on the generated die surface of the female die;

sixthly, determining the position and the style of the residual meat;

and step seven, designing a die for the generated die surface of the part drawing process.

The sixth step is as follows:

s61: determining the position and the style of the residual meat according to the slip lines of the CAE analysis result, and performing CAE analysis again after adding corresponding residual meat at the required position;

s62: after adding the residual meat, if the slip lines at the edge lines of the wheel cover are eliminated, the CAE analysis result is ended; if the cracking phenomenon is not eliminated, the process goes to S63;

s63: continuously adjusting the position and height of the residual meat, and setting the action stroke of the residual meat if the cracking phenomenon cannot be eliminated;

s64: and adjusting the stroke of the residual meat according to the CAE analysis result, thereby eliminating slippage and cracking.

The seventh step is as follows:

s71: the die structure is designed according to the drawing form of the common side wall outer plate, and the residual meat needs to be designed into a residual meat convex die with controllable stroke;

s72: determining the force and the stroke of a nitrogen spring of the residual meat male die according to the stroke and the forming force of the residual meat obtained from the CAE analysis result;

s73: the supporting rod is used for jacking and compressing the nitrogen spring, the stroke of the nitrogen spring is released along with the reduction of the supporting rod, and after the stroke of the nitrogen spring is completely released, the residual meat convex die continuously descends along with the supporting rod, so that the stroke controllability is realized.

The evaluation rules for the results of the CAE analysis are as follows:

(1) the thinning rate index range is 3% -20%;

(2) failure index < 0.75;

(3) the wrinkling index is less than 0.03;

(4) the sliding of the ridge does not exceed the R area of the product;

(5) the main strain index is more than 0.02, and the secondary strain index is more than or equal to 0;

(6) and the distance between the impact line of the fillet of the female die of the outer surface part and the visible surface of the product is more than 5mm according to the impact line index.

The preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications can be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.

Claims (9)

1. A drawing die for a vehicle body covering part is characterized by comprising an upper base plate (1), a lower base plate (2), a drawing female die (3), a drawing male die (4), a lower material pressing ring (6), a residual meat male die (5) and a guide plate (8); the drawing female die (3) is arranged on the upper base plate (1), the drawing male die (4) is arranged on the lower base plate (2), the residual meat male die (5) is positioned inside the drawing male die (4), and the drawing male die (4) and the residual meat male die (5) are connected in a vertically sliding fit mode through a guide plate (8); the lower material pressing ring (6) is connected with the lower bottom plate (2) in a vertically sliding fit manner through a guide plate (8); an elastic element (9) is arranged above the air cushion support rod under the press machine, and the elastic element (9) is fastened on the residual meat convex die (5).

2. The vehicle body covering part drawing die as claimed in claim 1, wherein the upper base plate (1) is connected to a press upper slide through a press quick clamping mechanism, and the lower base plate (2) is fixed to a press table through a press fastening bolt.

3. The vehicle body covering part drawing die as claimed in claim 1, wherein a limiting block (7) for limiting the residual meat punch (5) when the residual meat punch (5) moves upwards is arranged on the drawing punch (4).

4. The vehicle body covering part drawing die as claimed in claim 1, wherein guide plates (8) are mounted on the lower blanking ring (6), the drawing male die (4) and the residual meat male die (5), and the guide plates (8) have a guiding function.

5. The vehicle body covering drawing die as claimed in claim 1, wherein the elastic member is a nitrogen spring.

6. The design method of the residual meat convex die of the vehicle body covering part drawing die as claimed in claim 1, characterized by comprising the following steps:

step one, preparation of CAE analysis: loading the part curved surface data into plate forming simulation analysis software to complete the preparation of plate parameters;

step two, confirming the stamping direction: determining the drawing and stamping direction of the part according to the main ridge;

step three, supplementing the internal process of the part: filling the inner cavity of the part curved surface by adopting curved surface modeling software;

step four, supplement of the pressed noodles: adopting an offset curve method for the concave curve boundary of the part adapting to the shape of the wheel to supplement the pressing surface, and then performing process supplement on the part between the two curves;

step five, carrying out simulation analysis on the generated die surface of the female die;

sixthly, determining the position and the style of the residual meat;

and step seven, designing a die for the generated die surface of the part drawing process.

7. The method for designing the residual meat punch of the vehicle body covering part drawing die as claimed in claim 6, wherein the sixth step is as follows:

s61: determining the position and the style of the residual meat according to the slip lines of the CAE analysis result, and performing CAE analysis again after adding corresponding residual meat at the required position;

s62: after adding the residual meat, if the slip lines at the edge lines of the wheel cover are eliminated, the CAE analysis result is ended; if the cracking phenomenon is not eliminated, the process goes to S63;

s63: continuously adjusting the position and height of the residual meat, and setting the action stroke of the residual meat if the cracking phenomenon cannot be eliminated;

s64: and adjusting the stroke of the residual meat according to the CAE analysis result, thereby eliminating slippage and cracking.

8. The method for designing the residual meat punch of the vehicle body covering part drawing die as claimed in claim 6, wherein the seventh step is as follows:

s71: the die structure is designed according to the drawing form of the common side wall outer plate, and the residual meat needs to be designed into a residual meat convex die with controllable stroke;

s72: determining the force and the stroke of a nitrogen spring of the residual meat male die according to the stroke and the forming force of the residual meat obtained from the CAE analysis result;

s73: the supporting rod is used for jacking and compressing the nitrogen spring, the stroke of the nitrogen spring is released along with the reduction of the supporting rod, and after the stroke of the nitrogen spring is completely released, the residual meat convex die continuously descends along with the supporting rod, so that the stroke controllability is realized.

9. The method of designing a meat residual punch for a vehicle body covering member drawing die as recited in claim 6,

the evaluation rules for the results of the CAE analysis are as follows:

(1) the thinning rate index range is 3% -20%;

(2) failure index < 0.75;

(3) the wrinkling index is less than 0.03;

(4) the ridge line does not slide beyond the R area of the product;

(5) the main strain index is more than 0.02, and the secondary strain index is more than or equal to 0;

(6) and the distance between the impact line of the concave die fillet of the outer surface part and the visible surface of the product is more than 5 mm.

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