JP6029902B2 - Molding method and molding apparatus - Google Patents

Description

The present invention, in conventional molding methods it is difficult to mold a small area of the opening, and has a sufficient depth, shaping how the member for obtaining the surface quality good moldings Contact and The present invention relates to a molding apparatus.

  With the thinning of electrical appliances and the like, the demand for thin metal containers with a small opening area and deep shape is increasing, and several methods for forming metal containers, particularly deep metal containers, have been devised. Yes.

  For example, Patent Document 1 relates to multi-stage deep drawing, and after deep drawing with a punch having a diameter larger than that of a metal container, deep drawing is further performed with a punch having a smaller diameter in the next process, and finally metal This is a method of forming into a container shape. Patent Document 2 relates to a squeezing and squeezing process, and after forming into a shallow cup shape in the first process, the side wall of the cup is squeezed and stretched over several steps to form a final metal container shape. To be molded.

  On the other hand, blow molding is a method in which a metal plate material is sandwiched with a high-temperature mold, and the material is heated and then pressed with a high-pressure gas to be molded into a mold shape. A metal plate, particularly a plate made of an Al—Mg-based alloy with fine crystal grains causing superplastic deformation, has a large ductility at high temperatures, and is therefore used for forming a deep shape or a complicated shape. However, since blow molding is a stretch molding using the high ductility of the material, as shown in FIG. 1, a mold in which a female mold 1 having a small opening area and a blow mold 2 are paired is used. Then, if the molded member 5 is molded by blowing the gas 4 through the gas flow path 3, the material of the stretched portion of the molded member 5 is insufficient. Molding was difficult. Therefore, in order to extend a larger portion of the member 5 to be molded, which is a metal plate material, a female mold 1 and a blow mold 2 are paired as shown in FIG. In addition to the above-mentioned mold, blow molding may be performed using the male mold 6. As shown in FIG. 2 and FIG. 3 described later, the male mold 6 has a shoulder portion 7 having an R portion.

JP-A-1-258822 International Publication No. 00/69004 JP 2003-53438 A

  However, the molding methods described in Patent Document 1 and Patent Document 2 are molding methods at room temperature, and the ductility of the metal sheet material to be molded is poor, so that the molding method is performed in a very large number of steps, and many molds are required. It was. For example, when a metal plate material having a relatively high strength such as an Al—Mg alloy is used, breakage may occur during forming.

  Further, in blow molding using a male mold as shown in Patent Document 3, as shown in FIG. 3, in the shoulder portion 7 where the R of the male mold 6 is small, the member 5 to be molded is placed on the shoulder portion 7. While the contacted and the molded member 5 becomes familiar with the entire mold, the molded member 5 is locally pulled by the touch difference, so stress concentration occurs and only a deep sliding scratch occurs on the molded product. In addition, the reduction in the plate thickness is increased, and in the case of a container shape having a deep bottom, breakage may occur. In addition, there is a problem that wrinkles remain after molding unless the molded member 5 is properly stretched as a whole.

The present invention has been made in view of the above circumstances, and in order to obtain a molded article having a good surface quality, having a shape with a small area of the opening and a deep bottom, using blow molding, with fewer steps. and to provide a molding how you and forming part of the section.

The molding method according to the first aspect of the present invention includes:
A first step of preforming a member to be molded to obtain a preformed member;
The edge of the preforming member is sandwiched between a heated upper mold and a heated lower mold, and the upper mold, the preformed member, A second step of forming the preformed member so as to conform to the shape of the punch by blowing gas during
Including
The diameter of the punch is smaller than the diameter of the pre-formed member after the first step,
It is characterized by that.

  The position of the shoulder portion of the punch may be closer to the center axis of the punch than the position of the shoulder portion of the preforming member after the first step.

When the position in the height direction of the lowermost part of the punch matches the position in the height direction of the rising part of the preforming member,
In the cross section of the punch and the preformed member in a plane including the central axis of the punch,
The length of the straight line between the rising portion of the preforming member and the shoulder of the punch is the intersection of the rising portion of the preforming member, the perpendicular from the shoulder of the punch, and the preforming member. It may be larger than the length of the pre-formed member between.

In the first step,
The edge of the member to be molded is sandwiched between the heated upper mold and the heated lower mold,
The molded member is preformed so as to conform to the shape of the other punch by blowing a gas between the upper mold and the molded member while moving and stretching another punch. By doing so, the preformed member may be obtained.

  In the first step, the preformed member may be obtained by preforming the member to be molded using deep drawing or ironing.

  The second step may be repeated a plurality of times.

The molding apparatus according to the second aspect of the present invention is:
Molding the preformed member using the molding method described above;
It is characterized by that.

According to the present invention, the use of a blow molding, in fewer steps, small area of the opening, and the bottom has a deep shape molding how the member for obtaining a good molded article surface quality Contact and A molding apparatus can be provided.

It is sectional drawing which shows typically the blow molding method using the conventional female die. It is sectional drawing which shows typically the blow molding method using the conventional male type metal mold | die. In the blow molding method using the conventional male type metal mold | die, it is sectional drawing which shows typically the state which the to-be-molded member contacted the shoulder part of the metal mold | die. It is sectional drawing which shows typically the state of the to-be-molded member before the 1st process which concerns on embodiment of this invention. It is sectional drawing which shows typically shaping | molding of the to-be-shaped member in the 1st process which concerns on embodiment of this invention. It is sectional drawing which shows typically the state in the 2nd process which concerns on embodiment of this invention, while the punch is moving. It is sectional drawing which shows typically the state after a punch moves in the 2nd process which concerns on embodiment of this invention. It is sectional drawing which shows typically the state while the punch is moving in the 3rd process which concerns on embodiment of this invention. It is sectional drawing which shows typically the state after a punch moves in the 3rd process which concerns on embodiment of this invention. It is sectional drawing which shows typically the shape of the molded article which concerns on embodiment of this invention. It is sectional drawing which shows typically the shaping | molding method which suppresses the wrinkle of the molded article which concerns on embodiment of this invention.

  As a result of intensive studies, the inventor has compared the preformed member formed so as to approach the shape of the container in the first step and the shoulder of the punch used in the previous step in the second step after the second step. Because of the contact, avoid contact with the part where the thickness reduction of the pre-formed member is relatively large, the diameter is smaller than the diameter of the pre-formed member after the previous process is finished, and the maximum height is large. By moving the punch close to the shape of a simple container toward the preforming member and at the same time applying the gas pressure one or more times, a deeper shape can be obtained, and the surface quality can be improved. The present inventors have found that a good container can be formed and have come to achieve the present invention.

  The metal plate forming method according to the embodiment of the present invention utilizes blow molding. The molding method in the embodiment of the present invention includes a plurality of steps. Hereinafter, the forming apparatus 200, the material of the member 105 to be formed, and the metal container forming method by the first process, the second process, and the third process using the forming apparatus 200 will be described.

(Molding equipment)
The metal container molding apparatus 200 includes a blow mold 102 (upper mold), a lower mold 101, and a gas flow path 103. A gas 104 for blow molding passes through the gas flow path 103 and the molding apparatus 200. Be blown into. As will be described later, the first punch 108 is introduced into the molding apparatus 200 in the first process, the second punch 109 is introduced into the molding apparatus 200 in the second process, and the third punch is introduced into the molding apparatus 200 in the third process. The punch 110 is introduced (FIGS. 4 to 9).

(Molded member)
As the member to be molded 105 (metal plate material), for example, an aluminum alloy or the like is used. In particular, when an Al-Cu alloy, Al-Zn-Mg alloy, or Al-Mg alloy that can be refined is used, superplastic properties appear, and a high-temperature ductility of several hundred% or more is exhibited. More preferred. These alloys are difficult to perform multistage deep drawing and ironing, and forming a deep container shape is difficult. However, by using the forming method according to the embodiment of the present invention, a deep container shape can be formed. As an Al—Cu alloy, for example, a 2004 alloy is suitably used as a superplastic forming material, and as an Al—Zn—Mg based alloy, for example, a 7475 alloy is suitably used as a superplastic forming material. As the Al—Mg alloy, for example, an alloy having a large amount of added Mn, such as 5083 alloy, is preferable because fine crystal grains are easily obtained.

  In the following first to third steps, the temperatures of the member to be molded 105 (metal plate), the preformed member 112, and the blow mold 102 and the lower mold 101 are preferably in the range of 350 ° C. or higher and 550 ° C. or lower. Then, since the aluminum alloy exhibits superplastic deformation, the molded member 105 and the preformed member 112 exhibit a large elongation. More preferably, when the temperature is in the range of 470 ° C. or more and 550 ° C. or less, the superplastic deformation characteristics of the aluminum alloy can be maximized, and the molded member 105 and the preformed member 112 exhibit even greater elongation. .

  Hereinafter, the metal plate forming method will be described in detail.

(First step)
First, the molded member 105 is sandwiched between the heated blow mold 102 and the lower mold 101, and the molded member 105 is heated. That is, the member to be molded 105 is heated in a state of being bridged so as to straddle the concave portion of the lower mold 101 (FIG. 4).

  Next, as shown in FIG. 5, by using the pusher 117, the first punch 108 is moved from the lower side of the lower mold 101 in the direction of the arrow A <b> 1 to perform the overhang molding, and at the same time, through the gas flow path 103. Then, the gas 104 is blown into the molding apparatus 200, and the pressure of the gas 104 against the molding target 105 from the opposite side (from the upper side in FIG. 5) to the direction of the stretch molding by the first punch 108 (direction of arrow A1). Is applied so that the member 105 to be molded is blow molded so as to conform to the shape of the first punch 108. That is, in the first step, the member to be molded 105 is molded so as to follow the shape of the first punch 108, and the preformed member 112 is obtained. After the first step is completed, the flow of the gas 104 is temporarily stopped, and the first punch 108 is extracted from the molding apparatus 200. Here, the diameter D1 of the first punch 108 is larger than the diameter of the final shape of the molded product 120 after the third step described later (that is, the diameter D3 of the third punch 110). Further, in FIG. 5 of the first punch 108, the vertical direction (that is, the direction parallel to the mainstream traveling direction of the gas 104 in the molding apparatus 200 and the direction in which the molded member 105 extends before the first process starts) is used as a reference. And the length of the first punch 108 in the direction parallel to the traveling direction of the first punch 108 is the depth of the concave portion of the final shape of the molded product 120 after the third step (that is, the depth of the final shape of the metal container). Smaller than).

(Second step)
Next, as shown in FIGS. 6 and 7, a pre-formed member formed in the first step by moving the second punch 109 in the direction of the arrow A <b> 1 from the lower side of the lower mold 101 using the pusher 117. At the same time as the overhang forming for 112, the gas 104 is blown into the forming apparatus 200 via the gas flow path 103, and from the opposite side to the direction of the overhang forming by the second punch 109 (the direction of the arrow A1) (see FIG. 6 and By applying the pressure of the gas 104 to the preforming member 112 (from the upper side in FIG. 7), the preforming member 112 is blow-molded so as to conform to the shape of the second punch 109. That is, in the second step, the preforming member 112 is molded so as to follow the shape of the second punch 109. After the second step is completed, the flow of the gas 104 is temporarily stopped, and the second punch 109 is extracted from the molding apparatus 200. Here, the diameter D2 of the second punch 109 is smaller than the diameter D1 of the first punch 108. Further, in FIGS. 6 and 7 of the second punch 109, the vertical direction (that is, the direction parallel to the mainstream traveling direction of the gas 104 in the molding apparatus 200), and the molded member 105 before the start of the first process extends. The length of the first punch 108 in a direction perpendicular to the direction and parallel to the traveling direction of the second punch 109 is longer than the length of the first punch 108 in FIG. That is, in FIGS. 6 and 7, the length of the second punch 109 in FIG. 6 and FIG. 7 is larger than the depth of the preformed member 112 after the first step.

(Third process)
Next, as shown in FIGS. 8 and 9, a pre-formed member formed in the second step by moving the third punch 110 in the direction of arrow A <b> 1 from the lower side of the lower mold 101 using the pusher 117. At the same time as the overhang forming for 112, the gas 104 is blown into the forming apparatus 200 through the gas flow path 103, and from the opposite side to the direction of the overhang forming by the third punch 110 (the direction of the arrow A1) (FIG. 8 and FIG. By applying the pressure of the gas 104 to the preforming member 112 (from the upper side in FIG. 9), the preforming member 112 is blow-molded so as to conform to the shape of the third punch 110. That is, in the third step, the preforming member 112 is molded to follow the shape of the third punch 110, and becomes a molded product 120 used for the metal container (FIG. 10). After the third step is completed, the flow of the gas 104 is stopped and the third punch 110 is extracted from the molding apparatus 200. Here, the diameter D3 of the third punch 110 and the vertical direction in FIG. 8 and FIG. 9 (that is, the direction parallel to the mainstream traveling direction of the gas 104 in the molding apparatus 200 and before the first process starts). The length of the third punch 110 is the same as the final shape of the molded product 120, and the diameter D3 of the third punch 110 is the first direction. It is smaller than the diameter D2 of the double punch 109. 8 and 9, the length of the third punch 110 in the vertical direction is larger than the depth of the preforming member 112 after the completion of the second step (that is, in FIGS. 8 and 9 of the third punch 110). The length in the vertical direction is larger than the length in the vertical direction in FIGS. 6 and 7 of the second punch 109).

  Finally, the molded product 120 is removed from the molding apparatus 200. The molded product 120 is used for a metal container, for example.

  In the embodiment of the present invention, the “diameter” of the punch is the outer edge of the rising portion of each of the first punch 108, the second punch 109, and the third punch 110, as shown in FIGS. For example, the second punch 109 having a smaller diameter than the first punch 108 means that the outer edge of the rising portion of the second punch 109 is the rising portion of the first punch 108. It means that the size is completely surrounded by the outer edge of the.

In the forming method according to the embodiment of the present invention, by changing the punch diameter for each process and performing blow molding over a plurality of processes, the aluminum alloy material can be formed over a wide range of the molded member 105 and / or the preformed member 112. Not only can ductility be utilized, but the location where the reduction in the local thickness of the molded member 105 and / or the preformed member 112 due to the occurrence of stress concentration varies from process to process, so that the punch (first punch 108, The second punch 109 and / or the third punch 110) and the molded member 105 and / or the pre-formed member 112 can not only suppress the occurrence of sliding scratches, but also the molded member 105 and / or Alternatively, the pre-formed member 112 can be prevented from being broken and compared with the blow molding using a conventional male mold. 112, it can be molded more bottom deeper shape.
That is, in a conventional molding method using a male mold, stress concentration occurs at the punch shoulder until the member to be molded and / or the pre-molded member comes into contact with the shoulder of the punch and fits into the entire male mold. In addition to the occurrence of sliding flaws in the molded product, the material is locally stretched, resulting in a significant reduction in plate thickness, which sometimes leads to breakage. On the other hand, in the molding method according to the embodiment of the present invention, the position of the shoulder portion where the reduction in the plate thickness is increased due to the small R changes for each process. That is, the position of the shoulder 107a of the first punch 108 used in the first process (FIG. 5), the position of the shoulder 107b of the second punch 109 used in the second process (FIG. 7), and the third process The position of the shoulder 107c of the third punch 110 used is different (FIG. 9). Furthermore, in each previous step, the member to be molded 105 and / or the preformed member 112 is formed into a shape that gradually approaches the final shape of the molded product 120, so After the molded member 112 contacts the shoulder 107a, shoulder 107b, and shoulder 107c in the first step, the second step, and the third step, respectively, the first punch 108, the second punch 109, and the third punch respectively. The touch difference until the entire punch 110 is adjusted is short (that is, the molded member 105 and / or the pre-formed member 112 is adapted to the entire shape of the punch in a short time), and the shoulder 107a, shoulder 107b, and shoulder 107c. The stress concentration in the sheet is relaxed, and the occurrence of sliding flaws in the member to be molded 105 and / or the preformed member 112 and the local reduction in the plate thickness are suppressed. It is possible. In addition, in the first step, the second step, and the third step, the first punch 108, the second punch 109, and the third punch 110 are moved in the direction of the arrow A1, and the molded member 105 and / or the preliminary punch are moved. By blowing the gas 104 from the opposite side of the punching direction to the forming member 112 and applying pressure by the gas, the touch difference between the member to be formed 105 and the preforming member 112 and the punch is further reduced. (I.e., the time it takes for the molded member 105 and / or the preformed member 112 to conform to the overall shape of the punch can be further reduced).

  In addition, according to the forming method according to the embodiment of the present invention, since the high ductility of the metal plate material at a high temperature can be used, the depth of the formed product is increased in one step as compared with the multistage forming at room temperature. Is possible. Therefore, it is possible to realize a reduction in the number of processes and a reduction in mold costs. Further, in the molding method using the conventional male mold, the molded member cannot be uniformly extended, and the molded product may be wrinkled. However, according to the embodiment of the present invention. According to the molding method, the shape of the punch can be gradually changed to a shape close to the shape of the final molded product, and the molded member 105 and / or the preformed member 112 can be controlled to be stretched uniformly. It is also possible to suppress the generation of wrinkles in the molded product 120.

  As shown in FIGS. 5, 7, and 9, in the molding method according to the embodiment of the present invention, the shoulder of the punch used in each process is the shoulder of the pre-molded member 112 ( That is, it is closer to the center axis of the punch than the shoulder of the pre-formed member 112 after the previous process is finished. The central axes of the first punch 108, the second punch 109, and the third punch 110 are the centers of gravity when the outer edges of the rising portions of the respective punches are viewed from the upper side of the molding apparatus 200 (for example, the respective punches are viewed from above the molding apparatus 200). If the shape of the outer edge of the rising portion of the punch when viewed is circular, it is an axis that passes through the center of the circle and extends in the vertical direction in each figure. That is, the direction in which the central axis of each punch extends is a direction parallel to the traveling direction of the main flow of the gas 104 in the molding apparatus 200, and is perpendicular to the direction in which the member 105 to be molded before the first process starts. This is a direction parallel to the traveling direction of the first punch 108, the second punch 109, and the third punch 110. Here, since the position of the shoulder portion of the pre-formed member 112 after the completion of the previous step is the position of the shoulder portion of the punch used in the previous step, the horizontal direction in the figure of the shoulder portion 107b of the second punch 109 ( That is, it is a direction perpendicular to the traveling direction of the main stream of the gas 104 in the molding apparatus 200, a direction parallel to the extending direction of the molding target member 105 before the start of the first process, and the traveling direction of the second punch 109. The position in the vertical direction with respect to the horizontal direction in the figure of the shoulder 107a of the first punch 108 (that is, the direction perpendicular to the traveling direction of the main flow of the gas 104 in the molding apparatus 200) It is a direction parallel to the extending direction of the molded member 105 before the start of one process, and is located on the center side of the position of the first punch 108 in a direction perpendicular to the traveling direction of the first punch 108, and the shoulder 1 of the third punch 110. 7c in the horizontal direction (that is, a direction perpendicular to the traveling direction of the main flow of the gas 104 in the molding apparatus 200, and a direction parallel to the extending direction of the member 105 before starting the first step). The position in the direction perpendicular to the traveling direction of the third punch 110 is closer to the center than the horizontal position in the figure of the shoulder 107b of the second punch 109. As a result, it is possible to suppress local deformation caused by the first contact of the shoulder portion with the portion where the reduction in the plate thickness has increased in the previous step in the next step. The entire preformed member 112 can be easily deformed uniformly, and the occurrence of sliding flaws in the molded member 105 and / or the preformed member 112 can be suppressed.

  Hereinafter, a method for further reducing the generation of wrinkles in the preformed member 112 and the molded product 120 according to the embodiment of the present invention will be described. FIG. 11 shows a state in which the position in the height direction of the lowermost portion of the punch 111 and the position in the height direction of the rising portion 114 (second central axis) of the preforming member 112 coincide in the second process or the third process. FIG. 5 is a cross-sectional view schematically showing the positional relationship between the punch 111 and the preforming member 112 in a plane including the central axis 113 of the punch 111. In FIG. 11, the cross-sectional length (the length of the curve) of the pre-formed member 112 from the rising portion 114 of the pre-formed member 112 to the intersecting point 116 vertically lowered from the shoulder 115 of the punch 111 to the cross-section of the pre-formed member 112. Is a length L1 before molding. In addition, the length of the line segment when the rising portion 114 of the preforming member 112 and the shoulder portion 115 of the punch 111 are connected by a straight line is defined as a forming length L2. At this time, the shape of the punch 111 and the preforming member 112 and the shape of the punch 111 and the preforming member 112 are set so that the mid-length L2 is longer than the pre-molding length L1 in the cross section of the punch 111 and the preforming member 112 in any plane including the central axis 113. By determining the horizontal position, the preforming member 112 is always stretched and stretched during molding, so that the preforming member 112 does not become excessive and wrinkles are further generated in the molded product 120. It becomes possible to suppress.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation and application are possible. For example, in the present embodiment, the method of forming by the three steps of the first step, the second step, and the third step has been described, but the final shape is formed by using the two steps of the first step and the second step. Alternatively, it may be formed into a final shape using four or more steps by providing a fourth step after the third step.

  In the embodiment of the present invention, the form in which the molded member 105 is initially molded by using blow molding in the first step has been described. For example, the molded member 105 is generally deep drawn. The container-shaped preformed member 112 obtained by molding by ironing may be used in the second and subsequent steps.

  Further, in the embodiment of the present invention, the form in which the aluminum alloy plate is used as the material of the member to be molded 105 has been described. However, for example, another alloy or aluminum foil may be used as the material of the member to be molded 105.

1 Female mold 2 Blow mold 3 Gas flow path 4 Gas 5 Molded member 6 Male mold 7 Shoulder 101 Lower mold 102 Blow mold 103 Gas flow path 104 Gas 105 Molded member 107a Shoulder 107b Shoulder Portion 107c Shoulder 108 First punch 109 Second punch 110 Third punch 111 Punch 112 Pre-forming member 113 Center shaft 114 Standing portion 115 Shoulder 116 Intersection 117 Pusher 120 Molded product 200 Molding device

Claims (7)

A first step of preforming a member to be molded to obtain a preformed member;
The edge of the preforming member is sandwiched between a heated upper mold and a heated lower mold, and the upper mold, the preformed member, A second step of forming the preformed member so as to conform to the shape of the punch by blowing gas during
Including
The diameter of the punch is smaller than the diameter of the pre-formed member after the first step,
A molding method characterized by the above. The position of the shoulder portion of the punch is closer to the central axis of the punch than the position of the shoulder portion of the preformed member after the first step is completed.
The molding method according to claim 1. When the position in the height direction of the lowermost part of the punch matches the position in the height direction of the rising part of the preforming member,
In the cross section of the punch and the preformed member in a plane including the central axis of the punch,
The length of the straight line between the rising portion of the preforming member and the shoulder of the punch is the intersection of the rising portion of the preforming member, the perpendicular from the shoulder of the punch, and the preforming member. Greater than the length of the preformed member between
The shaping | molding method of Claim 1 or 2 characterized by the above-mentioned. In the first step,
The edge of the member to be molded is sandwiched between the heated upper mold and the heated lower mold,
The molded member is preformed so as to conform to the shape of the other punch by blowing a gas between the upper mold and the molded member while moving and stretching another punch. To obtain the preformed member,
The molding method according to any one of claims 1 to 3, wherein: In the first step, the preformed member is obtained by preforming the molded member using deep drawing or ironing.
The molding method according to any one of claims 1 to 3, wherein: Repeating the second step multiple times,
The molding method according to any one of claims 1 to 5, wherein: The preforming member is molded using the molding method according to any one of claims 1 to 6.
A molding apparatus characterized by that.

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