JP6844523B2 - Drawing method - Google Patents

Description

The present invention relates to a draw forming method for drawing a work panel.

In the manufacturing process of an automobile body or the like, it is widely practiced that a work panel such as a steel plate is formed into a molded body having a predetermined shape by press molding using a molding die. For example, examples of such a molded product include those having the shapes shown in FIGS. 10 (a) and 10 (b). As shown in the figure, the central portion of the molded body 10 is bulged in a mountain shape, and a standing wall including a steeply inclined upper wall portion 101 and a continuously inclined gently inclined lower wall portion 102 on one surface thereof. It has a shape portion 103.

Conventionally, in order to obtain such a molded body 10, for example, a draw molding apparatus 9 having an upper mold 91 and a lower mold 92 shown in FIG. 11 has been used. The upper die 91 is supported so as to be able to move up and down, and the work panel 100 is drawn and molded by pushing down the lower die cushion ring 93 arranged on the outer peripheral portion of the lower die 92.

As shown in FIG. 12, in the conventional draw forming method, the upper die 91 acts on the work panel 100 in the pressing direction indicated by the arrow. When the molded body 10 is to be molded by one press operation, the work panel 100 changes from the initial state W0 to the first deformed state W1 and further deformed to the second deformed state W2 as the upper die 91 descends. I will go. In this case, the amount of deformation increases in the standing wall shape portion 103 of the upper wall portion 101 and the lower wall portion 102 shown in FIG. 10 (b). Therefore, a large tension acts on the work panel 100, and the cross-sectional length L01 of the work panel 100 is finally extended to the length L11. As a result, there is a problem that the standing wall shape portion 103 is thinned and squeezed wrinkles and scratches are likely to occur. Further, if the wrinkle pressing force of the standing wall shape portion 103 is increased in order to suppress the occurrence of squeezing wrinkles, there is also a problem that squeezing due to material breakage occurs.

In order to deal with this kind of problem, for example, as described in Patent Document 1, the final processing member is brought into contact with the work panel from the side with a small amount of deformation toward the side with a large amount of deformation. A molding method for finishing the shape of the molded body has also been proposed.

Japanese Patent Application Laid-Open No. 08-257647

In the conventional drawing forming method, when the forming process of the standing wall-shaped portion having a large amount of deformation is started, the forming process of the portion other than the standing wall-shaped portion also proceeds in conjunction with a part. Therefore, a large tension is likely to act on the standing wall shape, and there is still room for improvement. Development of a molding method that can prevent the standing wall shape from becoming thinner and suppress the occurrence of squeezing wrinkles and scratches. Was desired.

An object of the present invention is to provide a draw forming method capable of preventing thinning of the standing wall shape portion and forming the shape without causing drawing cracks in the draw forming process of the shape including the standing wall shape portion. ..

The solution of the present invention for achieving the above object is premised on a draw forming method in which a work panel is subjected to a forming process including a gently inclined surface and a steeply inclined surface continuous thereto by using a drawing forming apparatus. .. The draw molding apparatus includes an upper mold having a cylinder, a lower mold having a concave molding surface corresponding to the gently inclined surface and a steeply inclined surface, and an inclined guide surface provided up and down via the cylinder. An upper cushion ring that can be displaced in the direction, a lower cushion ring that abuts on the upper mold or the upper cushion ring and can be displaced in the vertical direction within a restricted area, and an arrangement inside the upper cushion ring. Then, a convex molding surface corresponding to the concave molding surface and a close-up cam provided with a cam surface that is in sliding contact with the guide surface are provided. Then, as the drawing forming method, the upper mold is lowered while urging the upper mold cushion ring via the cylinder, the lower mold cushion ring is pushed down, and the upper mold cushion ring is used as the lower mold cushion ring. In the first molding process of pressure contacting with, the upper mold is further lowered, the cylinder is contracted, the gather cam is slid along the guide surface, and the convex molding surface of the gather cam is the lower mold. The configuration includes a second molding process of pressure contacting the concave molding surface of the above.

Due to this specific matter, the portion of the work panel including the gently sloping surface and the steeply sloping surface that is continuous with the gently sloping surface, which tends to be deformed more, is kept in the lower mold in the first molding process, and the second molding Since the drawing cam is slid in the processing to perform drawing forming, it is possible to form without causing drawing cracks while preventing thinning.

In the present invention, in the drawing forming process of the shape including the standing wall shape portion, the upper die is lowered to push down the lower die cushion ring, and the upper die cushion ring is pressed against the lower die cushion ring. , The upper mold is further lowered, the pulling cam is slid while contracting the cylinder, and the pulling cam is pressed against the lower mold in a second molding process. It is possible to prevent thinning and to mold without causing squeezing cracks.

It is sectional drawing which shows typically the structure of the draw molding method which concerns on Embodiment 1 of this invention, and the draw molding apparatus used in this method. It is sectional drawing which shows the post-process of FIG. It is sectional drawing which shows the post-process of FIG. It is explanatory drawing which showed the drawing | drawing process by the drawing forming method which concerns on Embodiment 1 step by step. It is sectional drawing which shows typically the structure of the drawing forming method which concerns on Embodiment 2 of this invention, and the drawing forming apparatus used in this method. It is sectional drawing which shows typically the structure of the draw molding method which concerns on Embodiment 3 of this invention, and the draw molding apparatus used in this method. It is a partial cross-sectional view which shows one step of the drawing molding method which concerns on Embodiment 3. It is a partial cross-sectional view which shows the post process of FIG. It is a partial cross-sectional view which shows typically the structure of the draw molding method which concerns on Embodiment 4 of this invention, and the draw molding apparatus used in this method. 10 (a) and 10 (b) are examples of molded products obtained by a draw molding method, FIG. 10 (a) is a perspective view showing a molded product, and FIG. 10 (b) is FIG. 10 (a). It is sectional drawing of the molded article including AA part. It is sectional drawing which shows typically the structure of the draw forming apparatus used in the conventional draw forming method. It is explanatory drawing which showed the drawing | drawing process by the conventional drawing forming method step by step.

Hereinafter, the draw forming method according to the embodiment of the present invention will be described with reference to the drawings.

1 to 9 are diagrams schematically showing a drawing molding method according to an embodiment of the present invention and a structure of a drawing molding apparatus used in this method. In the draw forming method according to each embodiment described below, the work panel 100 is formed by using the draw forming apparatus 1 to obtain a molded body 10 having a predetermined shape.

As shown in FIGS. 10 (a) and 10 (b), for example, the completed molded body 10 has a mountain-shaped central portion, and on one surface thereof, a steeply inclined upper wall portion 101 and a steeply inclined upper wall portion 101. It has a standing wall-shaped portion 103 including a continuously inclined lower wall portion 102. The upper wall portion 101 and the lower wall portion 102 are connected to each other via a rounded bent portion. The gently inclined lower wall portion 102 is formed so that the inclination angle θ ₂ with respect to the vertical axis B in the molded body 10 is larger than _{the inclination angle θ 1 of} the steeply inclined upper wall portion 101.

The work panel 100 is formed into a predetermined shape including the standing wall shape portion 103 by the drawing forming device 1, and is formed as a member forming a part of a vehicle body such as an automobile. The shape of the molded body 10 is shown in FIG. 10 if it has a standing wall shape portion 103 including a steeply inclined upper wall portion 101 and a continuously inclined gently inclined lower wall portion 102. It is not limited to the shape of the body 10.

(Embodiment 1)
1 to 3 are cross-sectional views schematically showing the structure of the draw forming method according to the first embodiment and the draw forming apparatus used in this method.

First, the structure of the draw forming apparatus 1 used in the draw forming method according to the first embodiment will be described. FIG. 1 shows an initial state of the draw forming process in the draw forming apparatus 1. The draw forming apparatus 1 includes a lower mold unit 11 on the fixed side and an upper mold unit 12 arranged above the lower mold unit 11 so as to face each other.

The lower mold 2 is provided in a bolster of a press mechanism (not shown) in the lower mold unit 11. The lower mold 2 is arranged at the center of the lower mold unit 11, and an annular groove space 21 is provided on the outside thereof. A lower cushion ring 3 is flexibly arranged in the groove space 21. The lower cushion ring 3 has a recess on the upper surface for holding the work panel 100.

The lower mold 2 has a convex panel molding surface 22 on the upper surface thereof, which corresponds to the shape of the lower surface of the work panel 100 constituting the molded body 10. Further, the lower mold 2 has a concave molded surface 23 corresponding to the standing wall shape portion 103 of the molded body 10. The concave forming surface 23 has a steeply inclined upper forming surface 231 and a gently inclined lower forming surface 232.

The upper die unit 12 is provided with the upper die 4 on a ram of a press mechanism (not shown). The upper die 4 is arranged at the center of the upper die unit 12 and has a concave panel forming surface 42 corresponding to the panel forming surface 22 of the lower die 2. An annular groove space 41 is provided on the outside of the panel forming surface 42 of the upper die 4, and the upper die cushion ring 5 is arranged flexibly.

The upper cushion ring 5 is attached to the upper die 4 via a cylinder 43 extending downward in the groove space 41 of the upper die 4. An air cylinder or the like that can expand and contract in the vertical direction can be applied to the cylinder 43. As a result, the upper die cushion ring 5 can be moved up and down in conjunction with the upper die 4, and can be moved up and down independently of the upper die 4 via the cylinder 43.

The upper cushion ring 5 has a convex portion on the lower surface for holding the work panel 100. The convex portion on the lower surface of the upper cushion ring 5 and the concave portion on the upper surface of the lower cushion ring 3 form a sandwiching portion 61 for sandwiching the work panel 100. Further, inside the upper die cushion ring 5, a panel forming surface 51 corresponding to the panel forming surface 22 of the lower die 2 and a guide surface 52 inclined inward in which the lower die 2 is arranged are provided. ..

Inside the upper cushion ring 5, a gathering cam 7 interposed between the upper mold 4 and the upper cushion ring 5 is provided. The gathering cam 7 includes a first cam surface 71 that is in sliding contact with the guide surface 52 of the upper die cushion ring 5, and a second cam surface 72 that is in sliding contact with the guide surface 44 of the upper die 4. A slide plate 62 having high lubricity and sliding characteristics is interposed between the first cam surface 71 and the upper cushion ring 5 and between the second cam surface 72 and the upper mold 4. There is.

Further, the gathering cam 7 is provided with a convex forming surface 73 on the surface facing the lower mold 2. The convex forming surface 73 of the gathering cam 7 is provided corresponding to the concave forming surface 23 of the lower mold 2, and is oblique to the gently inclined lower forming surface 232 and the steeply inclined upper forming surface 231. It is located above.

As a result, the close-up cam 7 moves diagonally downward via the slide plate 62 on the first cam surface 71 and the second cam surface 72 in conjunction with the lowering of the upper die 4 and the lowering of the upper die cushion ring 5. Sliding. When the gathering cam 7 slides, the convex forming surface 73 approaches the concave forming surface 23 of the lower mold 2 and is pressed against each other.

The lower cushion ring 3 is supported by a cushion pin 24 provided so as to penetrate the bottom surface 211 of the groove space 21. The lower end of the cushion pin 24 is connected to a cushion mechanism (not shown) provided below the bolster. The lower cushion ring 3 can be displaced in the vertical direction in the groove space 21 within the restricted area until the lower end of the lower cushion ring 3 comes into contact with the bottom surface 211.

(Drawing method)
Next, the draw forming method according to the first embodiment using the draw forming apparatus 1 will be described with reference to FIGS. 1 to 3.

In the draw forming process, the work panel 100 is placed on the upper surface of the lower cushion ring 3 in a state where the upper die unit 12 is raised and the die is opened in advance. Next, among the upper mold units 12, the upper mold 4 is lowered integrally with the ram, so that the end portion of the work panel 100 is fixed to the holding portion 61. As a result, the work panel 100 is set in the draw forming apparatus 1.

FIG. 1 shows an initial state of the draw forming process, in which the edge portion of the work panel 100 is sandwiched between the upper cushion ring 5 and the lower cushion ring 3. The cylinder 43 interposed between the upper die 4 and the upper die cushion ring 5 is extended to urge the upper die cushion ring 5 downward. By lowering the upper mold 4, the upper cushion ring 5 is pressed against the lower cushion ring 3. The gathering cam 7 is in a state of being retracted above the guide surface 52 of the upper cushion ring 5. Further, the lower mold cushion ring 3 is supported by the cushion pin 24 and is located above the groove space 21 of the lower mold 2.

Further, the upper mold 4 is lowered toward the molding position. As a result, the upper cushion ring 5 is lowered while being urged downward by the cylinder 43. The lower cushion ring 3 is pushed down by the upper cushion ring 5 and gradually descends in the groove space 21 together with the cushion pin 24 while maintaining a predetermined cushioning force by a cushion mechanism (not shown).

FIG. 2 shows a draw forming apparatus 1 in the process of forming following FIG. As the lower mold cushion ring 3 is pushed down, the work panel 100 approaches the panel forming surface 22 of the lower mold 2 and begins to partially abut. The work panel 100 is struck by the panel forming surface 22 of the lower mold 2, and is gradually drawn into a predetermined shape.

As the upper cushion ring 5 is further lowered, the panel forming surface 51 of the upper cushion ring 5 presses the work panel 100 with the panel forming surface 22 of the lower die 2. The work panel 100 comes into contact with the lower mold 2 in a range excluding the concave molding surface 23 of the lower mold 2, and has a shape substantially along the panel molding surface 22 (first molding process).

Here, the work panel 100 is held in the pressed state at the sandwiching portion 61 between the upper cushion ring 5 and the lower cushion ring 3. Further, the work panel 100 is held in a pressed state from above even between the panel forming surface 51 of the upper die cushion ring 5 and the lower die 2. This pressing force functions as a wrinkle pressing force for the work panel 100 to prevent the occurrence of squeezing wrinkles.

Further, at this time, as shown in FIG. 2, the gathering cam 7 is in a retracted state upward, and the work panel 100 is in a raised state on the concave forming surface 23 of the lower mold 2. The lower end of the lower cushion ring 3 is in contact with the bottom surface 211 of the groove space 21.

In this way, when the lower cushion ring 3 comes into contact with the bottom surface 211 of the groove space 21, the downward displacement of the lower cushion ring 3 is stopped. Since the lower mold 4 is in a continuous descending state, the cylinder 43 immediately shifts to the contraction operation when the downward displacement of the lower mold cushion ring 3 is stopped.

When the cylinder 43 starts to contract, the upper die 4 is lowered while accommodating the upper die cushion ring 5 in the groove space 41, and the drawing process of the work panel 100 proceeds. The gathering cam 7 slides along the guide surface 44 of the upper die 4 and the guide surface 52 of the upper die cushion ring 5, and moves forward diagonally downward. The convex forming surface 73 of the gathering cam 7 begins to come into contact with the work panel 100.

FIG. 4 is an explanatory view showing stepwise the drawing forming process of the standing wall shape portion 103 by the gathering cam 7. The gathering cam 7 acts on the work panel 100 in the pressing direction indicated by the arrow in the drawing, and applies a pressing force from diagonally above. The work panel 100 is gradually deformed from the initial state W0 that abuts on the convex forming surface 73 as the moving cam 7 advances, and becomes the first deforming state W1 that is attached to the convex forming surface 73, and the deformation further progresses. It changes to the second deformed state W2.

As shown in FIG. 3, finally, the work panel 100 is sandwiched between the convex forming surface 73 of the gathering cam 7 and the concave forming surface 23 of the lower mold 2 and pressure-welded (second molding process). .. The work panel 100 has a shape along the steeply inclined upper forming surface 231 and the gently inclined lower forming surface 232. As a result, the standing wall-shaped portion 103 is formed on the work panel 100, and the completed molded body 10 is obtained.

In the exemplary embodiment, the portion excluding the standing wall shape portion 103 is molded by the first molding process, and then molded into the final molded body 10 shape by the second molding process. In the first molding process, the portion of the work panel 100 other than the standing wall shape portion 103 has already been molded, and is pressed between the upper cushion ring 5 and the lower cushion ring 3 and the lower mold 2. Wrinkles are suppressed. Further, the portion of the work panel 100 that is formed into the standing wall-shaped portion 103 approaches the concave forming surface 23 of the lower die 2 and is struck by the lower die 2.

From this state, the second molding process is started, the gathering cam 7 is slid, and the standing wall shape portion 103 is formed on the work panel 100. Therefore, it is possible to suppress the amount of deformation of the work panel 100, prevent the standing wall shape portion 103 from becoming thin, and suppress the occurrence of squeezing wrinkles and the like.

In the conventional draw forming method shown in FIGS. 11 and 12, the amount of deformation increases in the standing wall shape portion 103, and the cross-sectional length L01 of the work panel 100 is finally extended to the length L11. .. Assuming that the elongation rate of the work panel 100 is (L11-L01) / L01, the elongation rate in this case is, for example, 121%.

On the other hand, according to the drawing forming method according to the first embodiment, as shown in FIG. 4, the steeply inclined upper wall portion 101 in the standing wall shape portion 103 of the work panel 100 is stretched to the cross-sectional length L1. Has been done. However, the portion of the work panel 100 (W0) before the draw forming process corresponding to the upper wall portion 101 had a cross-sectional length L0.

In this case, assuming that the elongation rate of the work panel 100 is (L1-L0) / L0, the elongation rate of the work panel 100 at the time when the draw forming process is completed is, for example, 8%, which is compared with the conventional forming method. The value is much smaller. That is, it is possible to perform drawing molding with high accuracy while suppressing the amount of deformation in the standing wall shape portion 103 to be small.

As described above, the standing wall shape portion 103 of the work panel 100, which tends to have a large amount of deformation by the drawing forming method according to this form, is left in the lower mold 2 in the first forming process. Since the drawing cam 7 is slid in the second molding process to perform drawing forming, it is possible to obtain a good molded body 10 by suppressing the occurrence of drawing wrinkles while preventing thinning. Become.

(Embodiment 2)
FIG. 5 is a cross-sectional view schematically showing the structure of the draw forming method according to the second embodiment and the draw forming apparatus used in this method. Since the drawing molding method according to the second to fourth embodiments described below has the same basic configuration as that of the first embodiment, the common configuration is the same as that of the first embodiment. A detailed description will be omitted using the reference numerals of.

In the embodiment shown in FIG. 5, the configuration of the lower mold unit 11 in the draw forming apparatus 1 is the same as that of the first embodiment, and the upper mold 4 and the upper mold unit 12 arranged above the lower mold unit 11 It is characterized by the configuration of the mold cushion ring 5.

An upper cushion ring 5 is provided at the center of the upper unit 12. The upper die cushion ring 5 is attached to the upper die 4 via a plurality of cylinders 43 provided in the groove space 41 of the upper die 4.

The upper cushion ring 5 is provided with a panel forming surface 53 corresponding to the panel forming surface 22 of the lower die 2 continuous with the surface forming the holding portion 61. The upper mold 4 is not provided with the panel forming surface 42, and is provided with a guide surface 44 to which the gathering cam 7 is in sliding contact. The upper type cushion ring 5 can be moved up and down in conjunction with the upper type 4, and can be moved up and down independently of the upper type 4 via the cylinder 43.

The draw forming method proceeds in the same manner as in the first embodiment, and by lowering the upper die 4, the upper die cushion ring 5 is lowered via the cylinder 43. The upper cushion ring 5 pushes down the lower cushion ring 3. The upper cushion ring 5 is pressed against the lower cushion ring 3. The work panel 100 is pressed against the panel forming surface 22 of the lower mold 2 and is gradually drawn and formed (first forming process).

The lower cushion ring 3 can be displaced in the vertical direction within the restricted area of the groove space 21, and when it comes into contact with the bottom surface 211 of the groove space 21, its downward displacement is stopped. As soon as the downward displacement of the lower cushion ring 3 is stopped, the cylinder 43 shifts to the contraction operation and starts the second molding process.

Further, the upper die 4 is lowered, and the upper die cylinder 43 is pressed against the panel forming surface 22 of the lower die 2 while contracting the cylinder 43. The gathering cam 7 slides along the guide surface 52, and the convex forming surface 73 is pressed against the concave forming surface 23 of the lower mold 2. The work panel 100 is sandwiched between the convex forming surface 73 of the gathering cam 7 and the concave forming surface 23 of the lower mold 2 and pressure-welded (second molding process). As a result, the standing wall-shaped portion 103 is formed on the work panel 100, and the completed molded body 10 is obtained.

In the draw forming method according to this form, in the upper die unit 12, the upper die cushion ring 5 and the gathering cam 7 act on the lower die 2 to perform the draw forming process. As a result, it is possible to control the pressing force on the work panel 100 by setting the load of the cylinder 43 provided in the upper die 4.

(Embodiment 3)
6 to 8 are cross-sectional views schematically showing the structure of the draw forming method according to the third embodiment and the draw forming apparatus used in this method.

In this form, the upper die unit 12 is characterized by the configuration of the upper die 4 and the upper die cushion ring 5, and the lower die unit 11 is characterized by the configuration of the lower die cushion ring 3. Other configurations in the draw forming apparatus 1 are the same as those in the first embodiment.

As shown in FIG. 6, the upper die 4 is common to the first embodiment in that it includes a concave panel forming surface 42 corresponding to the panel forming surface 22 of the lower die 2 and a guide surface 44 to which the gathering cam 7 slides. doing. The upper mold 4 is further configured to include a pressing surface 45 corresponding to the upper surface of the lower cushion ring 3 on the outside of the upper cushion ring 5. The upper cushion ring 5 includes a guide surface 52 to which the gathering cam 7 is slidably contacted, and a panel forming surface 54 corresponding to the lower side of the concave forming surface 23 of the lower die 2.

On the other hand, the lower cushion ring 3 is supported by the cushion pin 24, is divided into a first lower cushion ring 31 and a second lower cushion ring 32 having different strokes, and is flexibly arranged in the groove space 21. .. The second lower type cushion ring 32 is provided inside the first lower type cushion ring 31. For example, the first lower type cushion ring 31 is arranged so as to correspond to one side of the work panel 100, and the second lower type cushion ring 32 is arranged so as to correspond to the other three sides of the work panel 100.

As shown on the left side of FIG. 6, a step is provided on the bottom surface 211 of the groove space 21 so as to correspond to different strokes of the first lower cushion ring 31 and the second lower cushion ring 32. The lower end of the second lower type cushion ring 32 abuts on the upper part of the bottom surface 211 of the groove space 21, and the lower end of the first lower type cushion ring 31 abuts on the lower part of the bottom surface 211.

That is, the second lower cushion ring 32 can be displaced in the vertical direction within a restricted area shorter than that of the first lower cushion ring 31. Within the restricted area until the lower end of the first lower cushion ring 31 abuts on the lower stage of the bottom surface 211, the second lower cushion ring 32 stops its downward displacement before the first lower cushion ring 31. It is configured.

The upper surface of the first lower die cushion ring 31 is arranged so as to correspond to the pressing surface 45 on the outer peripheral portion of the upper die 4. One side of the work panel 100 is held by the sandwiching portion 61 between the pressing surface 45 of the upper die 4 and the first lower die cushion ring 31 (right side in FIG. 6), and the remaining three sides of the work panel 100 are the upper die cushion. It is held by the sandwiching portion 61 between the ring 5 and the second lower cushion ring 32 (left side in FIG. 6).

FIG. 7 is a cross-sectional view showing the right half of the draw forming apparatus 1 in FIG. In the initial state of the draw forming process, the edge portion of the work panel 100 is sandwiched between the pressing surface 45 of the upper die 4 and the upper surface of the first lower die cushion ring 31. When the upper die 4 is lowered, the first lower die cushion ring 31 is pushed down into the groove space 21. The cylinder 43 between the upper die 4 and the upper die cushion ring 5 is extended to urge the upper die cushion ring 5 downward, and the upper die cushion ring 5 descends integrally with the upper die 4.

As shown in FIG. 8, as the first lower mold cushion ring 31 is pushed down, the work panel 100 approaches the panel forming surface 22 of the lower mold 2 and begins to partially abut. The work panel 100 is pressed against the panel forming surface 22 of the lower mold 2 and is gradually drawn and formed. As the upper mold 4 further lowers, the lower end of the second lower mold cushion ring 32 comes into contact with the upper stage of the bottom surface 211 of the groove space 21 (see FIG. 6). The work panel 100 comes into contact with the lower mold 2 in a range excluding the concave molding surface 23 of the lower mold 2, and has a shape substantially along the panel molding surface 22 (first molding process).

When the lower end of the second lower cushion ring 32 comes into contact with the upper stage of the bottom surface 211 of the groove space 21, the downward displacement of the second lower cushion ring 32 is stopped. Since the lower die 4 is in a continuous descending state, the cylinder 43 immediately shifts to the contraction operation when the downward displacement of the second lower die cushion ring 32 is stopped.

As shown in FIG. 8, the first lower type cushion ring 31 continues the downward displacement within the restricted area until it comes into contact with the bottom surface 211 on the lower stage side of the groove space 21. Meanwhile, the upper die 4 descends while accommodating the upper die cushion ring 5 in the groove space 41, and subsequently pushes down the first lower die cushion ring 31. As a result, the drawing process of the work panel 100 proceeds.

Further, the gathering cam 7 moves forward diagonally downward along the guide surface 44 of the upper die 4 and the guide surface 52 of the upper die cushion ring 5, and forms the standing wall shape portion 103. Finally, as shown in FIG. 6, the work panel 100 is sandwiched between the convex forming surface 73 of the gathering cam 7 and the concave forming surface 23 of the lower mold 2 and press-welded (second molding process). .. As a result, the work panel 100 is molded into the molded body 10 including the standing wall shape portion 103.

In the draw forming method according to this embodiment, the upper die 4 provided on the ram of a press mechanism (not shown) pushes down the first lower die cushion ring 31. Therefore, unlike the first embodiment, the pressing force for pushing down the lower cushion ring 3 does not have to be controlled by the cylinder 43 provided in the upper die 4, and the drawing process can be performed more smoothly and efficiently. It becomes.

In the drawing forming apparatus 1, the arrangement form of the first lower die cushion ring 31 and the second lower die cushion ring 32 is not limited to that shown in the third embodiment, and for example, the entire groove space 21 of the lower die 2 is provided. Both the first lower type cushion ring 31 and the second lower type cushion ring 32 may be arranged flexibly over the circumference.

(Embodiment 4)
FIG. 9 is a cross-sectional view schematically showing the structure of the draw forming method according to the fourth embodiment and the draw forming apparatus used in this method.

In the embodiment shown in FIG. 9, the upper die unit 12 in the draw forming apparatus 1 is common to that of the third embodiment, and is characterized by the configuration of the lower die 2 of the lower die unit 11. As shown in the figure, the lower mold 2 is configured to include a guide cam 8 arranged corresponding to the gathering cam 7.

The guide cam 8 has a concave molding surface 81 corresponding to the standing wall shape portion 103 of the molded body 10, and includes a steeply inclined upper molding surface 811 and a gently inclined lower molding surface 812. In the lower mold 2, the guide cam 8 is slidably provided in the press direction indicated by the arrow in the drawing. The guide cam 8 can be moved up and down independently of the lower mold 2.

In this case, as the draw forming method, the first forming process and the second forming process can be efficiently and smoothly carried out in the same manner as in the third embodiment. In addition, when the molded body 10 has a shape including a negative angle portion in the standing wall shape portion 103, the lower mold 2 is provided with the guide cam 8 so as to be slidable, so that the standing wall in the second molding process is provided. The shape portion 103 can be formed without difficulty, and the formed work panel 100 can be easily separated from the lower mold 2.

The means for slidably supporting the guide cam 8 with respect to the lower mold 2 is not particularly limited, and various supporting means such as an air cylinder and a spring mechanism can be applied.

According to the drawing molding method according to each of the above-described embodiments, it is possible to prevent the standing wall shape portion 103 from being thinned in the molded body 10 and to accurately mold the standing wall shape portion 103 without causing squeezing wrinkles and squeezing cracks. ..

It should be noted that the draw forming method according to the above embodiment is an example in all respects and does not serve as a basis for a limited interpretation. The technical scope of the present invention is not to be construed solely by the above-described embodiment, but is based on the scope of claims. In addition, the technical scope of the present invention includes all modifications within the meaning and scope equivalent to the claims.

In each of the above embodiments, a draw forming apparatus 1 having an upper die 4, an upper die cushion ring 5 and a gathering cam 7 as an upper die unit 12 and a lower die 2 and a lower die cushion ring 3 as a lower die unit 11 is used. However, the configuration of each part of the draw forming apparatus 1 is not limited to this, and the configuration, arrangement, shape, and the like of each part may include other forms. .. For example, the cylinder 43 provided in the upper unit 12 is not limited to an air cylinder. Further, in each of the above-described embodiments, the case where the molded product 10 having the final shape shown in FIG. 10 is drawn and molded has been described, but it can also be applied to molded products having other shapes and is limited to this. It's not a thing.

The present invention can be suitably used for draw forming of work panels.

1 Draw forming device 11 Lower mold unit 12 Upper mold unit 2 Lower mold 21 Groove space 211 Bottom surface 22 Panel molding surface 23, 81 Concave molding surface 24 Cushion pin 3 Lower mold cushion ring 31 First lower mold cushion ring 32 Second lower mold Cushion ring 4 Upper mold 41 Groove space 42 Panel molding surface 43 Cylinder 44 Guide surface 5 Upper mold cushion ring 51, 53 Panel molding surface 52 Guide surface 62 Slide plate 7 Closed cam 71 First cam surface 72 Second cam surface 73 Convex molded surface 8 Guide cam 10 Molded body 100 Work panel 101 Upper wall part 102 Lower wall part 103 Standing wall shape part

Claims (1)

A draw forming method in which a work panel is subjected to a forming process including a gently inclined surface and a steeply inclined surface continuous thereto by using a draw forming apparatus.
The draw forming apparatus is
The upper mold equipped with a cylinder and
A lower mold provided with a concave molded surface corresponding to the gently inclined surface and the steeply inclined surface, and
An upper cushion ring that is provided with an inclined guide surface and can be displaced in the vertical direction via the cylinder.
A lower cushion ring that abuts on the upper mold or the upper cushion ring and can be displaced in the vertical direction within the restricted area.
It has a convex molding surface that is disposed inside the upper cushion ring and corresponds to the concave molding surface, and a gathering cam provided with a cam surface that is in sliding contact with the guide surface.
The first molding process in which the upper mold is lowered while urging the upper mold cushion ring via the cylinder, the lower mold cushion ring is pushed down, and the upper mold cushion ring is pressed against the lower mold cushion ring. When,
A second, in which the upper mold is further lowered, the cylinder is contracted, the gathering cam is slid along the guide surface, and the convex molding surface of the gathering cam is pressed against the concave molding surface of the lower mold. A drawing molding method including molding processing.

Images