JPH0238045B2 - - Google Patents

Description

Detailed Description of the Invention [Technical Field] The present invention relates to a method and apparatus for forming a bottomed cylindrical body by drawing a workpiece, particularly a low-rigidity workpiece containing a metal foil layer. The term "drawing" used in this specification includes not only drawing in a narrow sense, but also complex processing in which ironing, stretching, etc. are performed along with drawing.)

[Prior art] Japanese Patent Publication No. 57-4408 discloses a drawing method and apparatus for forming a bottomed cylindrical body by drawing a low-rigidity workpiece through cooperation between a male die and a female die. is disclosed. The low-rigidity workpiece may be a single layer of metal foil such as aluminum foil or chromic acid treated steel foil, or a suitable synthetic resin such as polypropylene, polyethylene or polycarbonate laminated on one or both sides of such metal foil. Laminates are advantageously used. The molded bottomed cylindrical molded body is used as a container for foods and the like.

As disclosed in the above-mentioned Japanese Patent Publication No. 57-4408, when the workpiece is a low-rigidity material, drawing is carried out in the usual manner as in the case of drawing a metal plate with relatively high rigidity. , unacceptable wrinkles are produced on the side walls of the compact. In order to prevent or suppress the occurrence of such wrinkles, the drawing method and apparatus disclosed in the above-mentioned Japanese Patent Publication No. 57-4408 uses a rigid core and an elastic surrounding member surrounding the rigid core. Therefore, during the drawing process, the workpiece is forcibly pressed against the inner surface of the female mold, thereby making the clearance between the inner surface of the female mold and the workpiece substantially zero.

[Problems with conventional technology]

According to the above-mentioned unique drawing process disclosed in Japanese Patent Publication No. 57-4408, it is possible to prevent or suppress the occurrence of wrinkles on the side wall of the molded product and form a good molded product. It turns out that there are many problems that need to be solved.

In other words, if the workpiece is forcibly pressed against the inner surface of the female mold during drawing and the clearance between the inner surface of the female mold and the workpiece is made to be substantially zero, the female mold will be The clearance between the inner surface of the mold and the outer surface of the side wall of the molded body is also substantially zero, and the outer surface of the side wall of the molded body tends to be relatively firmly attached to the inner surface of the female mold. Therefore, the resistance to separation of the molded body from the female mold is large, and (a) the molded body cannot be quickly separated from the female mold, resulting in an unacceptable separation timing delay in realizing continuous high-speed molding. (b) For example, when a knockout member is applied to the outer surface of the bottom wall of the molded body in order to separate the molded body from the female mold, excessive force is applied from the knockout member to the bottom wall of the molded body, causing the bottom wall to tends to produce undesirable deformations.

[Problem to be solved] The present invention has been made in view of the above facts, and its main technical problem is to forcibly press the workpiece against the inner surface of the female die during drawing processing, so that the inner surface of the female die is removed. Even in cases where the clearance between the mold and the workpiece is reduced to virtually zero, and the outer surface of the side wall of the molded body is relatively firmly attached to the inner surface of the female mold, the female mold and the male mold may be unnecessarily complicated. In addition, the molded body can be separated from the female die sufficiently quickly and without causing undesirable deformation of the molded body without making it expensive or unnecessarily complicating mold movement control during drawing. An object of the present invention is to provide an improved drawing method and apparatus that can perform the drawing process.

[Solution]

The gist of the solution of the present invention to achieve the above problem is (1) an opening-side member having an inner surface that regulates the opening-side portion on the outer surface of the side wall of the molded body; and an inner surface that regulates the bottom-side portion of the outer surface of the side wall of the molded body; (2) the opening side member and the opening side member are arranged in a female shape, and the opening side member is attached to the bottom side member so as to be movable in the axial direction between a combined position and a separated position; (3) A holding member in the female mold is pressed against the tip surface of the opening side member to hold the workpiece between them. When the peripheral edge portion is clamped, the opening side member is accordingly forced to the above-mentioned combined position against the elastic biasing action of the elastic means.

That is, according to the present invention, as a drawing forming method that achieves the above problems, a drawing forming method is used in which a workpiece is drawn and formed into a bottomed cylindrical formed body, and the outer surface of the bottom wall of the formed body is regulated. a knock-out stud having an upper surface that controls the opening side, an opening side member having an inner surface that regulates the opening side portion on the outer surface of the side wall of the molded body, a bottom side member having an inner surface that restricts the bottom side portion of the side wall outer surface of the molded body, and the opening side It includes a clamping member for clamping the peripheral edge of the workpiece between the front end surface of the member, and the opening side member is attached to the bottom side member so as to be movable in the axial direction between a combined position and a separated position. An elastic means for elastically biasing the opening side member to the separated position is interposed between the opening side member and the bottom side member, and the knockout stud and the holding member are connected to each other. A female mold that is movable in the axial direction relative to the bottom member and a male mold that is movable in the axial direction relative to the female mold are used, and the opening side of the female mold is used. A workpiece is placed on the front end surface of the member, and then the holding member is moved relatively toward the bottom member and pressed against the opening member, resisting the elastic biasing action of the elastic biasing means. the opening member to the combined position, and the peripheral edge of the workpiece is held between the opening member and the clamping member, and then the male die is relatively turned toward the female die. The female mold and the male mold work together to draw the workpiece into a cylindrical molded body with a bottom, and then the male mold is relatively moved in a direction away from the female mold. at least separating the male mold from the molded body, and after or simultaneously with separating the male mold from the molded body, relatively moving the clamping member in a direction away from the bottom member, and thus causing the elastic means to move away from the bottom member. The opening side member is brought together with the molded body to the separated position by the elastic biasing action of the molded body, and the bottom side member is separated from the molded body, and then the knockout stud is attached to the bottom side member and the bottom side member. moving it relative to the opening side member;
There is provided a drawing method characterized in that the knock-out stud moves the molded article relative to the opening-side member to separate the opening-side member from the molded article.

Further, according to the present invention, as a drawing forming apparatus that achieves the above-mentioned problems, the drawing forming apparatus is used to draw a workpiece to form a bottomed cylindrical formed body, and the outer surface of the side wall of the formed body is regulated. A knock-out stud having an upper surface, an opening-side member having an inner surface regulating an opening-side portion on the outer surface of the side wall of the molded article, a bottom-side member having an inner surface regulating the bottom-side portion on the outer surface of the side wall of the molded article, and the opening-side member. The opening side member is attached to the bottom side member so as to be movable in the axial direction between a combined position and a separated position. , elastic means for elastically biasing the opening side member to the separated position is interposed between the opening side member and the bottom side member, and the knockout stud and the holding member are connected to the bottom side member. a female mold that is movable in the axial direction relative to the side member; a male mold that is automatically movable in the axial direction relative to the female mold; and a clamping mold that is movable in the axial direction relative to the bottom member. The member is moved, the clamping member is pressed against the distal end surface of the opening member to bring the opening member into the combined position, and the clamping member is released from pressing the opening member to reduce the elasticity of the elastic means. female die setting means for forcing the opening side member to the separated position by a biasing action; knockout moving means for moving the knockout stud relative to the bottom side member; and the female die. A drawing forming apparatus is provided, comprising: mold moving means for moving the male mold relatively to the mold.

[Effect]

In the drawing method and apparatus of the present invention, when the female die is separated from the outer surface of the side wall of the drawn formed body with a bottom, the bottom member is separated from the bottom portion of the outer side wall of the formed body as a first step. Then, in a second step, the opening-side member is separated from the opening-side portion of the outer surface of the side wall of the molded body. Since the female mold is thus separated from the outer surface of the side wall of the molded body in two stages, it is possible to separate the female mold from the molded body sufficiently quickly and without causing undesirable deformation of the molded body. There is no need to make the construction of the female mold unnecessarily complicated and expensive. In addition, the relative movement of the holding member with respect to the bottom member inevitably positions the opening side member in the combined position and the separated position as required, which complicates mold movement control during drawing. It never happens.

[Preferred specific example]

Hereinafter, preferred embodiments of the present invention will be described in further detail with reference to the accompanying drawings.

Drawing Apparatus Referring now to FIG. 1, which illustrates the principal components of a preferred embodiment of a drawing apparatus constructed in accordance with the present invention, the illustrated drawing apparatus is designated generally by the numeral 2. It comprises a male mold and a female mold designated as a whole by number 4, and the female mold 4 includes a clamping member 6.

The male mold 2 has a rigid core member 8, which may be made of any suitable material, and a resilient surrounding member 10, which is conveniently made of synthetic or natural rubber. The core member 8 has a large diameter cylindrical upper part 1.
2. It has a small-diameter cylindrical intermediate portion 14 and a disc-shaped lower portion 16. The outer diameter of the disc-shaped lower part 16 is considerably larger than the outer diameter of the middle part 14, but somewhat smaller than the outer diameter of the upper part 12. The substantially cylindrical surrounding member 10 is disposed outside the intermediate portion 14 between the upper portion 12 and the lower portion 14 of the core member 8, and surrounds the side surface of the intermediate portion 14. The outer diameter of the surrounding member 10 is cylindrical at the middle part in the vertical direction, a truncated conical cylinder tapered upward at the upper part, and a truncated conical cylinder tapered downward at the lower part. It is the shape. The inner diameter at the upper part of the surrounding member 10 is substantially the same as the outer diameter of the intermediate portion 14 of the core member 8, but the inner diameter of the surrounding member 1
The inner diameter at the middle and lower part of 0 is the core member 8
Advantageously, the outer diameter of the intermediate portion 14 is somewhat larger than the outer diameter of the intermediate portion 14, with an annular space 17 existing between the two. If desired, the inner diameter of the middle and lower portions of the surrounding member 10 can be made to be substantially the same as the outer diameter of the middle portion 14 of the core member 8. The upper end surface and upper inner circumferential surface of the surrounding member 10 may be connected to the lower surface of the upper portion 12 and the intermediate portion 14 of the core member 8, as necessary.
Although the lower end surface of the surrounding member 10 is brought into contact with the upper surface of the lower part 16 of the core member 8, the lower end surface of the surrounding member 10 is not bonded thereto but is radially attached thereto. It is convenient to be able to move freely. The male mold 2 having the core member 8 and the surrounding member 10 as described above is mounted so as to be movable in the vertical direction,
It is raised and lowered by suitable mold moving means (not shown) which itself may be of known form.

The illustrated female mold 4 includes a knockout stud 18, a bottom member 2, which can be formed from any suitable material.
0 and an opening side member 22. The knockout stud 18 has a disc-shaped upper part 24 and a support shaft 26 extending downward from the lower surface of the upper part. The support shaft 26 is mounted to be movable in the vertical direction, and the knockout stud 18 is moved up and down by suitable knockout moving means (not shown), which itself may be of a known form. As will become clear from the following description, the upper surface of the upper portion 24 of the knockout stud 18 regulates the outer surface of the bottom wall of the formed body to be drawn. The bottom member 20, which has a generally cylindrical shape, is connected to a stationary support structure (not shown).
is fixed. An opening penetrating vertically is formed in the center of the bottom member 20. The lower half 28 of the opening has a cylindrical shape, and its inner diameter corresponds to the outer diameter of the upper part 24 of the knock-out stud 18 (more specifically, the upper half 28 has a cylindrical shape).
(The outer diameter is substantially the same as, or slightly larger than, the outer diameter of The upper half 30 of the opening has a truncated conical shape that tapers downward, and the inner diameter of the lower end of the upper half 30 matches the inner diameter of the lower half 28 . The opening side member 22 has an annular upper part 32 and an annular leg part 34 extending downward from the lower surface of the upper part 32. The opening side member 22 is attached to the bottom side member 20 so as to be movable in the vertical direction (that is, in the axial direction of the formed body to be drawn). In detail, the bottom member 20
The upper end of the opening side member 22 has a dish-shaped recess 36 corresponding to the shape of the upper part 32 of the opening side member 22.
An annular groove 38 extending further downward from the recess 36 is formed in correspondence with the leg portion 34 . The opening side member 22 is attached to the bottom side member 20 so as to be movable in the vertical direction by slidably inserting its legs 34 into the grooves 38.
The bottom surface of the groove 38 and the leg portion 3 inserted therein
An elastic means 40, which may be a compression coil spring, is interposed between the lower end of the spring 4 and the lower end of the spring 4. Such resilient means 40 resiliently bias the open side member 22 to the raised spaced position shown in FIG. 1 (i.e., spaced upwardly from the bottom side member 20). Opening side member 22
A truncated conical opening 42 that tapers downward is formed in the center of the upper portion 32 . As will become clear from the explanation later, the elastic means 4
When the opening side member 22 is lowered against the elastic biasing action of 0 and is combined with the bottom side member 20, the inner circumferential surface of the opening 42 matches the inner circumference of the upper half 30 of the opening of the bottom side member 20. It cooperates with the surface to regulate the outer surface of the side wall of the truncated conical tube shape of the formed object to be drawn.
(See also Figures 2 and 3).

The holding member 6 has an annular shape with a circular opening 44 formed in the center. The inner diameter of the circular opening 44 gradually increases upward, and the minimum inner diameter at the lower end is the same as that of the opening 42 in the opening side member 22.
Advantageously, the outer diameter is slightly larger than the maximum outer diameter at the upper end. The clamping member 6 is mounted so as to be movable in the vertical direction, and can be raised and lowered by suitable female setting means (not shown), which itself may be of a well-known form. As will become clear from the following description, this female mold setting means cooperates with the elastic means 40 to move the opening side member 22 of the female mold means 4 to the raised and separated position shown in FIG. 1 and to the raised and separated position shown in FIGS. 3 and the lowered combined position shown in FIG.

Drawing Method Next, a drawing method using the drawing device as described above will be described.

First, as shown in FIG.
Place 6. The workpiece 46 may be a single layer of metal foil such as aluminum foil or chromic acid-treated steel foil (the thickness of this metal foil may be about 7 to 200 μm), or one or both sides of such metal foil may be coated with polypropylene, Low-rigidity workpiece materials, such as laminates made of suitable synthetic resins such as polyethylene or polycarbonate, are advantageously used.

Next, the holding member 6 is lowered and pressed against the tip end surface of the opening side member 22 in the female mold 4 with a relatively large force. Thus, as shown in Figure 2,
The opening side member 2 resists the elastic biasing force of the elastic means 40.
2 is lowered and brought into close contact with the bottom member 20, and the female mold 4
is forced into a combined state. At the same time, the workpiece 4
The clamping member 6 is pressed against the distal end surface of the opening-side member 22 with the peripheral edge of the workpiece 46 sandwiched therebetween, and thus the peripheral edge of the workpiece 46 is sufficiently securely clamped between the opening-side member 22 and the clamping member 6. Ru.

Thereafter, the male mold 2 is lowered to the lowest position (drawing end position) shown in FIG. In this way, as can be understood by referring to FIG. 3, a drawing process is applied to the center part of the workpiece 46 by the cooperation of the male die 2 and the female die 4, resulting in a disc-shaped shape. A bottomed inverted truncated conical cylinder-shaped molded body having a bottom wall 48, a side wall 50 in the shape of a truncated conical cylinder extending upward from the periphery of the bottom wall 48, and an annular flange 52 extending radially outward from the side wall 50. 54 is molded. The inner surface of the bottom wall 49 of the molded body 54 is regulated by the lower surface of the male die 2, and the inner surface of the side wall 50 of the molded body 54 is regulated by the lower outer peripheral surface of the male die 2. On the other hand, the outer surface of the bottom wall 48 of the molded body 54 is regulated by the upper surface of the knockout stud 18, and the outer surface of the side wall 50 is regulated by the inner circumferential surfaces of the bottom member 20 and the opening member 22. More specifically, the opening side portion 50a of the outer surface of the side wall 50 of the molded body 54 is regulated by the inner peripheral surface defining the opening 42 in the opening side member 22,
The remainder of the outer surface of the side wall 50 of the molded body 54, ie, the bottom portion 50b, is regulated by the inner circumferential surface defining the upper half 30 of the opening in the bottom member 20. As can be understood by comparing and referring to FIGS. 2 and 3, during the drawing process, the elastic surrounding member 10 in the male die 2, especially its lower part, gradually expands in radius as the drawing process is performed. Due to this elastic deformation, the drawn portion of the workpiece 46 is elastically pressed against the inner peripheral surfaces of the bottom side member 20 and the opening side member 22 in the female mold 4. . This prevents or suppresses the formation of undesirable wrinkles on the side wall 50 of the molded body 54 even though the workpiece 46 has low rigidity (this point is explained in the above feature). Kosho 57-
Please refer to Publication No. 4408).

When the drawing process is completed as described above, the fourth
As shown in the figure, the male die 2 is raised, thereby separating the male die 2 from the molded body 54.

Thereafter, as shown in FIG. 5, the holding member 6 is raised. If desired, the clamping member 6 can be raised substantially simultaneously with the raising of the male mold 2. When the holding member 6 is raised, the female mold 4
The pressing force applied to the opening side member 22 at is released, and therefore, by the elastic biasing action of the elastic means 40, the opening side member 22 is raised to the raised separation position shown in FIG. 4 are placed in the separated state shown in FIG. The drawn body 54 attaches to the open side member 22 and is raised therewith, thus separating the formed body 54 from the bottom side member 20.

Next, as shown in FIG. 6, the knockout stud 18 in the female die 4 is raised. In this way, as can be understood by comparing and referring to FIGS. 5 and 6, the upper surface of the knockout stud 18 comes into contact with the bottom wall 48 of the molded body 54, causing the molded body 54 to rise. The molded body 54 is thus separated from the opening side member 22.

Thereafter, the molded body 54 is removed from the knockout stud 18, and drawing forming for the next workpiece is then started in the same manner as described above.

〔effect〕

Regarding the drawing method and apparatus as described above, the following facts should be noted.

The present inventors initially performed drawing forming of the molded body 54 using a drawing device in which the bottom side member 20 and the opening side member 22 of the female die 4 were integrally configured. In such a forming method, as is easily understood, the knock-out stud 18 is formed after drawing without going through the state shown in FIG.
is raised, thereby raising the molded body 54, and the molded body 54 is separated from the bottom side member 20 and simultaneously separated from the opening side member 22. Therefore,
The side wall 50 of the molded body 54 is entirely connected to the female mold 4 at the same time.
separated from However, in such a molding method, separation of the molded body 54 from the female mold 4, more specifically, separation of the side wall 50 of the molded body 54 from the inner circumferential surfaces of the bottom side member 20 and the opening side member 22, which are integrally constituted. (a) The rise of the knockout stud 18 and the accompanying rise of the molded body 54 are delayed somewhat from the expected timing; and (b) the separation of the molded body 54 from the knockout stud 18 is large.
Excessive force is applied to the bottom wall 48 of the molded body 54, which tends to deform the bottom wall 48 of the molded body 54 upwardly into a dome shape from the substantially flat state at the end of the drawing process. It turns out that it exists. It will be understood by referring to FIG. 3 that the entire outer surface of the side wall 50 of the molded body 54 has a large resistance to separation from the inner peripheral surfaces of the bottom member 20 and the opening member 22, which are integrally constructed. During the drawing process, the elastic surrounding member 10 of the male die 2 elastically presses the workpiece 46 against the inner circumferential surfaces of the bottom side member 20 and the opening side member 22, so that the bottom clearance between them becomes substantially zero. This is thought to be due to the fact that the outer surface of the side wall 50 of the molded body 54 is relatively firmly attached to the inner circumferential surfaces of the bottom member 20 and the opening member 22.

However, according to the above-described drawing method and apparatus according to the present invention, the female mold 4 is removed after the drawing process is completed.
When separating the molded body 54 from the bottom member 20, the entire outer surface of the side wall 50 of the molded body 54 is simultaneously separated from the bottom member 20.
And, rather than being separated from the inner circumferential surface of the opening side member 22, it is separated in two stages. That is, the side wall 5 of the molded body 54 is changed from the state shown in FIG. 4 to the state shown in FIG.
A portion 50b of the outer surface of the bottom member 22 is separated from the inner peripheral surface of the bottom member 22 (first step). After that,
By changing from the state shown in FIG. 5 to the state shown in FIG. 6, the remaining portion 50a of the outer surface of the side wall 50 of the molded body 54 is
separated from the inner circumferential surface of the When the outer surface of the side wall 50 of the molded body 54 is separated from the female mold 4 in two stages as described above, according to experiments conducted by the present inventors, the separation resistance at each stage is sufficiently reduced, and thus It has been confirmed that the molded body 54 can be successfully separated from the female mold 4 at the desired timing and without causing undesirable deformation of the bottom wall 48 or the like of the molded body 54.

In the drawing method and apparatus according to the present invention, the structure of the apparatus (particularly the female die 4) is somewhat more complicated than that of the conventional method, but there is no need to make it unnecessarily complicated and expensive. Further, since the selective positioning of the opening side member 20 in the female mold 4 is performed in conjunction with the vertical movement of the clamping member 6, mold movement control etc. are not unnecessarily complicated.

[Modification or modification example]

Although preferred specific examples of the drawing method and apparatus according to the present invention have been described above in detail with reference to the accompanying drawings, the present invention is not limited to such specific examples, and without departing from the scope of the present invention. Of course, various modifications and modifications are possible.

For example, although the drawing method and apparatus of the present invention have been described with respect to drawing of a bottomed cylindrical molded body 50 having a side wall 50 in the shape of a truncated conical cylinder tapering toward the bottom wall 48, the drawing forming method and apparatus of the present invention have been described. The method and apparatus can be applied not only to a polygonal truncated pyramidal cylinder shape but also to a bottomed cylindrical molded body having a side wall having a cylindrical shape or a prismatic cylinder shape.

[Brief explanation of drawings]

1 to 6 are simplified diagrams showing the main components of a preferred embodiment of the drawing device according to the invention, together with the workpiece and the molded body, at each stage of the preferred embodiment of the drawing method according to the invention, respectively. Cross-sectional view. 2... Male type, 4... Female type, 6... Holding member, 8
... Rigid core member, 10 ... Elastic surrounding member, 18
... Knockout stud, 20 ... Bottom side member,
22... Opening side member, 40... Elastic means, 46...
...Work material, 54... Molded object.

Claims (1)

[Scope of Claims] 1. A drawing method for forming a cylindrical molded body with a bottom by drawing a workpiece, comprising: a knock-out stud having an upper surface regulating the outer surface of the bottom wall of the molded body; and a side wall of the molded body. An opening-side member having an inner surface regulating the opening-side portion on the outer surface, a bottom-side member having an inner surface regulating the bottom-side portion on the outer surface of the side wall of the molded body, and a workpiece between the tip surface of the opening-side member and the opening-side member. The opening side member is attached to the bottom side member so as to be movable in the axial direction between a combined position and a separated position, and the opening side member and the bottom side member are connected to each other. An elastic means for elastically biasing the open side member to the separated position is interposed between the two, and the knockout stud and the clamping member are axially moved relative to the bottom side member. A female mold that is freely movable and a male mold that is movable in the axial direction relative to the female mold are used, and a workpiece is placed on the tip surface of the opening side member of the female mold. Then, the holding member is moved relatively toward the bottom member and pressed against the opening member, and the opening member is brought into the combined position against the elastic biasing action of the elastic biasing means. , sandwiching the peripheral edge of the workpiece between the opening member and the clamping member, and then moving the male mold relatively toward the female mold to separate the female mold and the male mold. Drawing the workpiece into a cylindrical molded body with a bottom through collaboration, then separating the male mold from the molded body by relatively moving the male mold in a direction away from the female mold, After or at the same time as separating the male die from the molded body, the holding member is relatively moved in a direction away from the bottom side member, and the opening side member is thus moved by the elastic biasing action of the elastic means. and separating the bottom member from the molded body, and then moving the knockout stud relative to the bottom member and the opening member. ,
A drawing-forming method comprising: moving the molded body relative to the opening-side member using the knock-out stud to separate the opening-side member from the molded body. 2. The drawing method according to claim 1, wherein the male die includes a rigid core member and an elastic surrounding member surrounding the side surface of the rigid core member. 3. The workpiece is a low-rigidity material containing a metal foil layer.
A drawing method according to claim 1 or 2. 4. A drawing device for forming a cylindrical molded body with a bottom by drawing a workpiece, and a knock-out stud having an upper surface that regulates the outer surface of the bottom wall of the molded body, and an opening side portion of the outer surface of the side wall of the molded body. For holding the peripheral edge of the workpiece between the opening-side member having an inner surface for regulating, the bottom-side member having an inner surface for regulating the bottom portion of the outer surface of the side wall of the molded body, and the tip surface of the opening-side member. The opening side member is attached to the bottom side member so as to be movable in the axial direction between the combined position and the separated position, and the opening side member is provided between the opening side member and the bottom side member. Resilient means are interposed to elastically bias the side members to the separated position, and the knock-out stud and the clamping member are female-shaped and movable in the axial direction relative to the bottom member. a male mold that is automatically movable in the axial direction relative to the female mold; and a male mold that moves the clamping member relative to the bottom member, and moves the clamping member to the distal end surface of the opening member. The opening side member is pressed to the combined position, and the pressing of the opening side member by the holding member is released so that the opening side member is forced to the separated position by the elastic biasing action of the elastic means. a female mold setting means for forming a male mold; a knockout moving means for moving the knockout stud relative to the bottom member; a mold moving means for moving the male mold relative to the female mold; A drawing forming device characterized by comprising: 5. The drawing apparatus according to claim 4, wherein the male mold includes a rigid core member and an elastic surrounding member surrounding a side surface of the rigid core member. 6 The workpiece is a low-rigidity material containing a metal foil layer,
A drawing device according to claim 4 or 5.