JP7368689B2 - Manufacturing method for automobile exterior panels - Google Patents

Description

The present disclosure relates to a mold set and a method for manufacturing an automobile exterior panel.

In recent years, automobile exterior panels such as door panels have become thinner due to demands for lighter weight. When the exterior panel is made thinner, a decrease in tension rigidity becomes a problem. For example, when an exterior panel is pressed by hand, it easily deforms.

Patent Document 1 describes an automobile door structure that achieves improved tension rigidity while suppressing increases in weight and cost. In Patent Document 1, a tension rigidity reinforcing material is provided in a space formed between a door outer panel and a door inner panel to be joined.

Japanese Patent Application Publication No. 2003-205741

However, as described in Patent Document 1, when providing a tension stiffness reinforcing material to suppress a decrease in tension stiffness, it is necessary to manufacture the tension stiffness reinforcing material separately from the door panel. In this case, manufacturing costs and labor are required.

SUMMARY OF THE INVENTION Therefore, an object of the present disclosure is to provide a mold set for molding an automobile exterior panel and a method for manufacturing an automobile exterior panel that suppresses a decrease in tensile rigidity while reducing manufacturing costs and labor.

In order to achieve the above object, the present disclosure provides a mold set for molding an automobile exterior panel, comprising a punch mold and a holder mold having a flow stopper extending in at least one direction, The shape of the top surface of the punch mold is a curved surface, and the flow stopper has a convex shape or a concave shape, and the convex top part or the concave bottom part forms the top surface of the punch mold along at least one direction. It matches the shape of a part of the surface.

The present disclosure also provides a mold set for molding an automobile exterior panel, which includes a punch mold and a holder mold having a flow stopper extending in at least one direction, the top surface of the punch mold being has a curved shape, the flow stopper has a convex shape or a concave shape, and the holder mold has a curved surface adjacent to the flow stopper along the extending direction of the flow stopper, The curved surface portion matches the shape of a portion of the top surface of the punch die along at least one direction.

The present disclosure also provides a method for manufacturing an automobile exterior panel using a mold set, wherein the mold set includes a punch mold, a holder mold having a stopper extending in at least one direction, and a die. a mold, the top surface of the punch mold has a curved shape, the flow stopper has a convex shape or a concave shape, and the convex top part or the concave bottom part extends along at least one direction. (a) a metal plate is sandwiched between the holder die and the die die; (b) the sandwiched metal plate is Pressing with the punch mold to form a press-formed product, (c) cutting out the first part press-molded with the punch mold from the press-forming product, and (d) cutting the flow stopper from the press-forming product. (e) joining the second part to the part of the first part press-formed by a part of the top surface of the punch die;

Further, the present disclosure provides a method for manufacturing an automobile exterior panel using a mold set, wherein the mold set is a mold set for forming an automobile exterior panel, and the mold set includes a punch mold and a punch mold in at least one direction. a holder mold having a flow stopper that extends, the top surface of the punch mold has a curved shape, the flow stopper has a convex shape or a concave shape, and the holder mold has a flow stopper that extends. a curved surface portion adjacent to the flow stop portion along the extending direction of the stop portion, the curved surface portion matching the shape of a portion of the top surface of the punch die along at least one direction; (a) sandwiching a metal plate between the holder mold and the die die; (b) pressing the sandwiched metal plate with the punch die to form a press-formed product; (c) ) Cutting out a first part press-formed with the punch die from the press-formed product, (d) cutting out a second part press-formed with the stopper part and the curved surface part from the press-formed product, (e ) In the first part, the second part is joined to a press-molded part of the top surface of the punch die.

According to the present disclosure, cost reduction during manufacturing can be achieved by utilizing the conventionally discarded portion of the metal plate as a reinforcing member. Further, when the metal plate is held between the holder mold and the die mold, a reinforcing member can be formed by the stopper part, so that it is possible to save the effort of separately manufacturing the reinforcing member. As a result, it is possible to manufacture an automobile exterior panel that is thin and suppresses a decrease in tension rigidity while reducing manufacturing costs and labor.

FIG. 1 is a diagram of an exterior panel of an automobile door according to an embodiment viewed from the back side. FIG. 2 is a diagram of the longitudinal reinforcing member viewed from the stretching direction. FIG. 3 is a cross-sectional view taken along line III-III in FIG. FIG. 4 is a perspective view showing a notch provided in the vertical reinforcing member. FIG. 5 is a perspective view showing the horizontal reinforcing member fitted into the notch of the vertical reinforcing member. FIG. 6 is a plan view of a press-formed product obtained by press-working a single steel plate. FIG. 7 is a diagram showing a mold set for molding a press-molded product. FIG. 8 is a diagram showing a state in which a steel plate is pressed using a mold set. FIG. 9 is a flowchart illustrating an example of a procedure of a method for manufacturing an exterior panel. FIG. 10 is a diagram showing the results of evaluating the tension rigidity of the exterior panel of the embodiment. FIG. 11 is a diagram illustrating a mold set for molding a flange having a shape that follows the joint portion of the exterior material. FIG. 12 is a diagram of a reinforcing member having a different shape, viewed from the stretching direction. FIG. 13 is a diagram in which a vertical reinforcing member consisting only of convex portions is provided with a notch for crossing the horizontal reinforcing member. FIG. 14 is a perspective view showing the horizontal reinforcing member fitted into the notch of the vertical reinforcing member.

In the following, the automobile exterior panel of the present disclosure will be described as an exterior panel of an automobile door. Note that the automobile exterior panel may be a panel of other parts of the automobile, such as a hood or a roof.

<Exterior panels of automobile doors>
FIG. 1 is a diagram of an exterior panel 100 of an automobile door according to the present embodiment viewed from the back side. The member indicated by the broken line in FIG. 1 is a doorknob provided on the front side of the exterior panel 100. In the following description, the vertical direction is the direction that corresponds to the height of the vehicle when the exterior panel 100 is attached to the vehicle, and the lateral direction is the direction that corresponds to the vehicle length of the vehicle.

The exterior panel 100 includes an exterior material 110, vertical reinforcing members 121 and 122, and horizontal reinforcing members 123 and 124.

The exterior material 110 is formed by pressing a steel plate with a thickness of 0.55 mm using a mold set described below. The exterior material 110 has a curved shape that becomes convex toward the front side toward the center in the vertical direction. Note that there are no particular restrictions on the shape of the exterior material 110.

The vertical reinforcing members 121, 122 and the horizontal reinforcing members 123, 124 are members extending in one direction. The vertical reinforcing members 121, 122 and the horizontal reinforcing members 123, 124 are joined to portions of the exterior material 110 where the tensile rigidity is low. The vertical reinforcing members 121 and 122 are joined to the back surface of the exterior material 110 along the vertical direction. The lateral reinforcing members 123 and 124 are joined to the back surface of the exterior material 110 along the lateral direction. The vertical reinforcing members 121, 122 and the horizontal reinforcing members 123, 124 are bonded to the back surface of the exterior material 110 using, for example, mastic adhesive. The reinforcing members 121 to 124 are formed from the same steel plate as the exterior material 110.

FIG. 2 is a diagram of the longitudinal reinforcing member 121 viewed from the stretching direction. Hereinafter, the direction perpendicular to the stretching direction of the longitudinal reinforcing member 121 will be referred to as the width direction. Although FIG. 2 shows the longitudinal reinforcing member 121, the shapes of the other reinforcing members 122 to 124 when viewed from the stretching direction are the same as the longitudinal reinforcing member 121.

The vertical reinforcing member 121 has a hat-shaped shape, when viewed from the stretching direction, including a trapezoidal convex portion 120A and flanges 120B and 120C adjacent to the convex portion 120A in the width direction. The vertical reinforcing member 121 is fixed to the exterior material 110 by bringing the top surface 120D of the convex portion 120A into close contact with the back surface of the exterior material 110. Similarly, the other reinforcing members 122 to 124 are also fixed to the exterior material 110 with the top surface 120D of each convex portion 120A in close contact with the back surface of the exterior material 110. Note that each of the reinforcing members 121 to 124 is fixed to the exterior material 110 by being joined at a plurality of locations along the stretching direction.

FIG. 3 is a cross-sectional view taken along line III-III in FIG. Note that FIG. 3 shows only the joint portion between the exterior material 110 and the vertical reinforcing member 121. The vertical reinforcing member 121 joined to the exterior material 110 has a shape that follows the joint portion of the exterior material 110. Specifically, as described above, the exterior material 110 has a curved shape. Further, the top surface 120D of the convex portion 120A of the vertical reinforcing member 121 is joined to the back surface of the exterior material 110. Therefore, the top surface 120D of the convex portion 120A of the vertical reinforcing member 121 has a shape that follows the curve of the exterior material 110.

Note that the vertical reinforcing member 121 only needs to be joined in close contact with a portion of the exterior material 110 with low tensile rigidity, and as shown in FIG. 3, there may be a portion that is not in close contact with the exterior material 110. Therefore, it is sufficient that the top surface 120D of the convex portion 120A of the vertical reinforcing member 121 matches at least the shape of the exterior material 110 in the portion where the tensile rigidity is low. Similarly, the other reinforcing members 122 to 124 have shapes corresponding to the joint portions of the exterior material 110.

The vertical reinforcing members 121 and 122 and the horizontal reinforcing members 123 and 124 cross each other and are joined to the exterior material 110. In this embodiment, the vertical reinforcing members 121 and 122 are provided with notches, and the horizontal reinforcing members 123 and 124 are fitted into the notches to avoid interference between the members.

FIG. 4 is a perspective view showing a notch 130 provided in the vertical reinforcing member 121. FIG. 5 is a perspective view showing a state in which the horizontal reinforcing member 123 is fitted into the notch 130 of the vertical reinforcing member 121.

A notch 130 is formed by, for example, laser cutting a part of the convex portion 120A of the vertical reinforcing member 121 along the stretching direction. The length of the notch 130 in the extending direction is longer than the length of the horizontal reinforcing member 123 in the width direction. Thereby, the horizontal reinforcing member 123 can be fitted into the notch 130. With the horizontal reinforcing member 123 fitted into the notch 130 of the vertical reinforcing member 121, a region 130A where the flanges 120B and 120C of the vertical reinforcing member 121 overlap with the flanges 120B and 120C of the horizontal reinforcing member 123 is, for example, a spot. The vertical reinforcing member 121 and the horizontal reinforcing member 123 are joined by welding. Note that the vertical reinforcing member 121 and the horizontal reinforcing member 123 may be joined by arc welding or mastic adhesive.

Note that two notches are formed in the vertical reinforcing member 121. Then, the lateral reinforcing members 123 and 124 are fitted into each notch. Further, like the vertical reinforcing member 121, the vertical reinforcing member 122 is also provided with notches, and the horizontal reinforcing members 123 and 124 are fitted into the notches.

In this way, the reinforcing members 121 to 124 reinforce the exterior material 110 by being joined to the back surface of the exterior material 110. This increases the tensile rigidity of the exterior panel 100. That is, in this embodiment, the tensile rigidity of the exterior panel 100 is not ensured by increasing the thickness of the exterior material 110, but is ensured by the vertical reinforcement members 121, 122 and the horizontal reinforcement members 123, 124. .

<About press-formed products>
The exterior material 110 and reinforcing members 121 to 124 constituting the exterior panel 100 are formed from a single pressed steel plate.

FIG. 6 is a plan view of a press-formed product 20 obtained by press-working a single steel plate. The press-formed product 20 is formed by pressing a steel plate using a mold set that will be described later. A first part 21 shown by a broken line and a second part 22 shown by a chain line are molded into the press-formed product 20. By cutting out the first part 21 from the press-formed product 20, the exterior material 110 is formed. Further, by cutting out the second part 22 from the press-formed product 20, vertical reinforcing members 121, 122 and horizontal reinforcing members 123, 124 are formed. Specifically, the second component 22 becomes the convex portion 120A of the reinforcing members 121 to 124.

Note that the second part 22 is molded to surround the first part 21. A portion of the second part 22 along the vertical direction of the first part 21 is cut out from the second part 22 to form the vertical reinforcing members 121 and 122. Further, portions of the second part 22 along the lateral direction of the first part 21 are cut out from the second part 22 to form the lateral reinforcing members 123 and 124.

Conventionally, only the first part 21 was cut out from the press-formed product 20, and the other parts were discarded. In this embodiment, by molding the second parts 22, which will become the reinforcing members 121 to 124, in parts that were conventionally discarded, it is possible to reduce the manufacturing cost of the exterior panel 100.

<About the mold set>
Next, a mold set for molding the press-molded product 20 shown in FIG. 6 will be described.

FIG. 7 is a diagram showing a mold set 10 for molding the press-molded product 20. As shown in FIG. FIG. 8 is a diagram showing a state in which the steel plate 5 is pressed by the mold set 10. The mold set 10 includes a punch mold 1, a holder mold 2, and a die mold 3.

The holder mold 2 has a through hole 2A through which the punch mold 1 passes, and a flow stop portion 2B formed along the through hole 2A. The die mold 3 is arranged to face the holder mold 2. The flow stop portion 2B is a convex portion that protrudes toward the die mold 3 side.

The die mold 3 and the holder mold 2 sandwich the peripheral edge portion of the steel plate 5 arranged so as to cover the through hole 2A of the holder mold 2. The die mold 3 has a recess 3A recessed on the opposite side of the holder mold 2 at a position facing the flow stopper 2B. The punch die 1 presses the steel plate 5 sandwiched between the holder die 2 and the die die 3 toward the die die 3 side through the through hole 2A of the holder die 2, so that the steel plate 5 is The first part 21 is molded. Further, the steel plate 5 sandwiched between the holder mold 2 and the die mold 3 is pressed by the flow stopper part 2B. The second part 22 is formed on the steel plate 5 by being pressed by the flow stopper 2B. Thereby, a press-molded product 20 in which the first part 21 and the second part 22 are molded is obtained.

<About the flow stopper>
As described above, the second part 22 pressed and molded by the stopper portion 2B becomes the convex portion 120A of the reinforcing members 121 to 124. The top surface 120D of this convex portion 120A needs to have a shape that follows the curve of the exterior material 110. Therefore, by making the top of the convex stopper portion 2B follow the shape of the top surface 1A of the punch die 1 for molding the first part 21 that will become the exterior material 110, the top surface 120D of the convex portion 120A is , the shape follows the curvature of the exterior material 110.

Specifically, the shape of the top of the stopper portion 2B along the vertical direction matches the shape of a portion of the top surface 1A of the punch die 1 (the broken line area 11 in FIG. 7) along the vertical direction. This broken line region 11 includes a portion where the tensile rigidity of the exterior material 110 to be molded is low.

Further, the top of the stopper portion 2B along the lateral direction matches the shape of a portion of the top surface 1A of the punch die 1 (dotted chain line region 12 in FIG. 7) along the lateral direction. This dot-dash line region 12 includes a portion where the tensile rigidity of the exterior material 110 to be molded is low.

By configuring the stopper portion 2B as described above, the discarded second part 22 of the steel plate 5 can be molded, and the first part 21 and the second part 22 can be molded in the same pressing process. The reinforcing members 121 to 124 formed by pressing the flow prevention portion 2B can be joined to the exterior material 110 in close contact.

<Method for manufacturing exterior panels>
FIG. 9 is a flowchart illustrating an example of a procedure for manufacturing the exterior panel 100.

First, the peripheral portion of the steel plate 5 is sandwiched between the holder die 2 and the die die 3, and a press work is performed in which the steel plate 5 is pressed with the punch die 1 (S1). As a result, a press-molded product 20 in which the first part 21 and the second part 22 are molded is molded. Next, a first part 21 and a second part 22 are cut out from this press-formed product 20 (S2). As a result, the exterior material 110 and reinforcing members 121 to 124 are formed.

Next, notches 130 are formed in the vertical reinforcing members 121 and 122 (S3). For example, the notch 130 is formed by laser cutting a portion of the convex portion 120A. The horizontal reinforcing members 123 and 124 are fitted into the notches 130 of the vertical reinforcing members 121 and 122 that have been formed, and spot welding is performed with the vertical reinforcing members 121 and 122 and the horizontal reinforcing members 123 and 124 crossing each other (S4). Thereafter, the reinforcing members 121 to 124 are bonded to the back surface of the exterior material 110 using mastic adhesive (S5). As a result, the exterior panel 100 is formed.

In this way, the exterior material 110 and the reinforcing members 121 to 124 can be formed at the same time by the press processing in S1, and the parts that were previously discarded can be effectively used, which reduces the manufacturing cost and reduces the tension stiffness. It is possible to manufacture an exterior panel 100 that suppresses.

<Example>
Next, by using the exterior panel 100 of this embodiment, a test was conducted to confirm that the tension rigidity did not decrease even when the panel was made thinner.

FIG. 10 is a diagram showing the results of evaluating the tension rigidity of the exterior panel 100 of this embodiment. The exterior panel 100 of the example of the present disclosure shown in FIG. 10 has a thickness of 0.5 mm and a weight of 3.57 kg. This weight includes the weight of the exterior material 110 and the weight of the reinforcing members 121 to 124. Further, the exterior panel cited as a comparative example has a thickness of 0.65 mm and a weight of 3.94 kg.

A load of 90 N was applied to these two exterior panels, and the amount of deflection of the panels was evaluated. In the example of the present disclosure, the amount of deflection is approximately 5.5 mm. On the other hand, in the comparative example, it is about 7.9 mm. In this way, it can be seen that in the example of the present disclosure, the amount of deflection is small and the tensile rigidity is not reduced, although the example is lighter than the comparative example.

<Modified example>
Modifications of this embodiment will be described below.

In the above embodiment, the reinforcing members 121 to 124 have the top surface 120D of each convex portion 120A joined to the back surface of the exterior material 110, but the flanges 120B and 120C are joined to the back surface of the exterior material 110. You can. In this case, the flanges 120B and 120C have a shape that follows the joint portion of the exterior material 110.

FIG. 11 is a diagram illustrating a mold set for molding flanges 120B and 120C having a shape that follows the joint portion of exterior material 110. FIG. 11 is a diagram corresponding to a part of FIG. 8. The holder mold 2 has a curved surface portion 2C adjacent to the flow stop portion 2B. The curved surface portion 2C extends in the vertical direction and the horizontal direction similarly to the flow stop portion 2B. The curved surface portion 2C along the vertical direction matches the shape of a part of the top surface 1A of the punch mold 1 (the broken line area 11 in FIG. 7) along the vertical direction. Further, the top of the curved surface portion 2C along the lateral direction matches the shape of a portion of the top surface 1A of the punch die 1 (dotted chain line region 12 in FIG. 7) along the lateral direction. The flanges 120B and 120C formed by this curved surface portion 2C have a shape that follows the curve of the exterior material 110.

Further, the shape of the reinforcing members 121 to 124 when viewed from the stretching direction is not limited to the shape shown in FIG. FIG. 12 is a diagram of a reinforcing member having a different shape, viewed from the stretching direction. As shown in FIG. 12(A), the reinforcing member viewed from the stretching direction may have an R-curved shape, or may have a triangular shape as shown in FIG. 12(B).

The reinforcing members 121 to 124 do not need to have flanges 120B and 120C. In other words, the reinforcing members 121 to 124 may consist only of the convex portion 120A. FIG. 13 is a diagram in which a vertical reinforcing member 121 consisting of only a convex portion 120A is provided with a notch 131 for crossing the horizontal reinforcing member. A part of the side surface of the convex portion 120A is cut out in the width direction to form flanges 131A and 131B. A cutout 131 is formed in the portion where the flanges 131A and 131B are formed.

FIG. 14 is a perspective view showing a state in which the horizontal reinforcing member 123 is fitted into the notch 131 of the vertical reinforcing member 121. When consisting only of the convex portion 120A, the lateral reinforcing member 123 has flanges 120E and 120F extending in the width direction at a portion in the extending direction. The portions of the horizontal reinforcing member 123 provided with the flanges 120E and 120F are fitted into the notches 131 of the vertical reinforcing member 121. With the horizontal reinforcing member 123 fitted into the notch 131 of the vertical reinforcing member 121, a region 131A where the flanges 131A and 131B of the vertical reinforcing member 121 overlap with the flanges 120E and 120F of the horizontal reinforcing member 123 is spot welded. Then, the vertical reinforcing member 121 and the horizontal reinforcing member 123 are joined.

Furthermore, although the exterior panel 100 has a structure in which four reinforcing members 121 to 124 are joined to the exterior material 110, if the reinforcing member is joined to a portion of the exterior material 110 with low tension rigidity, the reinforcing member The number can be changed as appropriate. For example, only the vertical reinforcing member 121 may be joined to the exterior material 110, or the vertical reinforcing member 121 and the horizontal reinforcing member 123 may be joined to the exterior material 110.

Furthermore, although the flow stopper 2B has a convex shape that protrudes toward the die mold 3 side, it may have a concave shape that is recessed toward the side opposite to the die mold 3. In this case, the concave portion 3A (FIG. 8) provided in the die mold 3 becomes a convex portion protruding toward the holder mold 2 side.

1 Punch mold 2 Holder mold 2B Stopper part 2C Curved part 3 Dice mold 5 Steel plate 10 Mold set 20 Press-formed product 21 First part 22 Second part 100 Exterior panel 110 Exterior material 121, 122 Vertical reinforcing member 123 , 124 Lateral reinforcing member

Claims (2)

A method for manufacturing an automobile exterior panel made of steel plate using a mold set, the method comprising:
The mold set is
punch mold and
a holder mold having a flow stopper extending in at least one direction;
die mold and
Equipped with
The flow stopper is continuous in the stretching direction and has an annular shape,
The shape of the top surface of the punch mold is a curved surface,
The flow stopper has a convex shape or a concave shape, and a convex top part or a concave bottom part matches the shape of a part of the top surface of the punch mold along at least one direction,
(a) sandwiching a metal plate between the holder mold and the die mold;
(b) pressing the sandwiched metal plate with the punch mold to form a press-formed product;
(c) cutting out a first part press-molded with the punch mold from the press-formed product;
(d) cutting out a second part press-formed at the stopper part from the press-formed product;
(e) joining the second part to a press-molded part of the top surface of the punch mold in the first part;
A method for manufacturing automobile exterior panels. A method for manufacturing an automobile exterior panel made of steel plate using a mold set, the method comprising:
The mold set is
A mold set for forming automobile exterior panels,
punch mold and
a holder mold having a flow stopper extending in at least one direction;
Equipped with
The flow stopper is continuous in the stretching direction and has an annular shape,
The shape of the top surface of the punch mold is a curved surface,
The flow stopper has a convex shape or a concave shape,
The holder mold has a curved surface portion adjacent to the flow stopper along the extending direction of the flow stopper,
The curved surface portion matches the shape of a portion of the top surface of the punch mold along at least one direction,
(a) sandwiching a metal plate between the holder mold and the die mold;
(b) pressing the sandwiched metal plate with the punch mold to form a press-formed product;
(c) cutting out a first part press-molded with the punch mold from the press-formed product;
(d) cutting out a second part press-formed with the stopper part and the curved surface part from the press-formed product;
(e) joining the second part to a press-molded part of the top surface of the punch mold in the first part;
A method for manufacturing automobile exterior panels.

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