CN116529063A

CN116529063A - Press apparatus and method for producing press-formed article

Info

Publication number: CN116529063A
Application number: CN202180078905.9A
Authority: CN
Inventors: 西村隆一; 柏原义之; 綛田良之
Original assignee: Nippon Steel and Sumitomo Metal Corp
Current assignee: Nippon Steel Corp
Priority date: 2020-11-27
Filing date: 2021-11-26
Publication date: 2023-08-01
Also published as: EP4253025A1; JP7056812B1; EP4253025A4; US20230405957A1; JPWO2022114113A1

Abstract

The pressing device (1) comprises: a 1 st die part (2) having a 1 st working surface (2 a); a 2 nd die part (3) having a 2 nd working surface (3 a); a 1 st support part (4) for supporting the 1 st mold part (2); and a 2 nd support portion (5) that supports the 2 nd mold portion (3). At least one of the 1 st die part (2) and the 2 nd die part (3) has a gap (S1, S2) in which the dimension of the pressing direction in a non-loaded state is uneven in two directions orthogonal to each other in at least part of an overlap region (R1) in which the 1 st machining surface (2 a) and the 2 nd machining surface (3 a) overlap when viewed from the pressing direction. The minimum dimension of the gap (S1) in the non-loaded state at the inner region (R1 u) of the overlapping region (R1) located inward from the center line (G) and the outer edge is smaller than the minimum dimension of the gap (S1) in the non-loaded state at the outer region (R1S).

Description

Press apparatus and method for producing press-formed article

Technical Field

The present invention relates to a press apparatus and a method for manufacturing a press-formed article.

Background

In general, a pressing apparatus presses a pressing object into a shape corresponding to the shape of a machined surface of a die by disposing the pressing object between a pair of dies and bringing the pair of dies closer to each other. The pair of dies are supported by a pair of support members capable of relative movement in the pressing direction, respectively. A pair of support members are, for example, a slider and a pad. At the time of press forming, a pressing load is applied to the die from the support member. At this time, the support member may be deflected by a reaction force from the mold to the support member. The deflection may affect the shape accuracy of the press-formed article.

Japanese patent application laid-open publication 2016-179486 (patent document 1) proposes a pressing device for suppressing deflection generated in a die due to a reaction force at the time of press forming. The pressing device comprises a rigidity distribution member arranged between the die and the supporting member. The rigidity distribution member makes the rigidity of compression for the pressing direction exhibit a predetermined distribution in a plane orthogonal to the pressing direction.

Further, japanese patent No. 4305645 (patent document 2) discloses the following: plate molding simulation was performed to determine the deflection distribution of the mold corresponding to the molding stroke.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open publication 2016-179486

Patent document 2: japanese patent No. 4305645

Disclosure of Invention

Problems to be solved by the invention

In the above-described conventional pressing apparatus, it is necessary to prepare a rigidity distribution member. In 1 member, it is not easy to make the rigidity different and obtain an arbitrary distribution of rigidity. In addition, in order to reduce the deflection of the support portion (for example, the slider and the pad) of the press, there is also a method of changing the structure of the support portion or the support structure thereof. This is a large-scale and costly countermeasure, and its effect is limited in most cases.

The purpose of the present disclosure is to provide a press device and a method for manufacturing a press-formed article, which can reduce the influence of deflection of a support portion of a die on press forming with a simple structure.

Solution for solving the problem

The pressing device according to the embodiment of the present invention is a pressing device for press-forming a pressing target. The pressing device includes: a 1 st die part having a 1 st working surface that contacts one surface of the pressing object during press forming; a 2 nd die part having a 2 nd working surface which is in contact with the other surface of the pressing object at the time of press forming; a 1 st support portion that supports the 1 st mold portion; and a 2 nd support portion that supports the 2 nd die portion and is capable of reciprocating in a pressing direction with respect to the 1 st support portion. At least one of the 1 st die portion and the 2 nd die portion has a gap in which the dimension of the pressing direction in the no-load state of at least part of an overlapping region in which the 1 st processing face and the 2 nd processing face overlap when viewed from the pressing direction is uneven in two directions orthogonal to each other when viewed from the pressing direction. The minimum dimension in the pressing direction in the no-load state of the gap at the inner region on the inner side of the center line, which is a set of midpoints of line segments connecting the center of gravity of the overlapping region and an arbitrary position of the outer edge of the overlapping region, is smaller than the minimum dimension in the pressing direction in the no-load state of the gap at the outer region on the outer side of the center line.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present disclosure, the influence of the deflection of the support portion of the die of the press apparatus on the press forming can be reduced with a simple structure.

Drawings

Fig. 1 is a diagram showing a configuration example of a pressing device according to the present embodiment.

Fig. 2 is a view showing a state in which the 2 nd die portion of the pressing device shown in fig. 1 is positioned at the bottom dead center.

Fig. 3 is a diagram showing a modification of the structure in which a gap is formed in a mold portion.

Fig. 4 is a plan view of the 1 st die shown in fig. 3 viewed from the pressing direction (upward).

Fig. 5 is a diagram showing a distribution of gap sizes in the no-load state of the 1 st mold part shown in fig. 4.

Fig. 6 is a diagram showing a distribution of gap sizes at the bottom dead center of the 1 st die part shown in fig. 4.

Fig. 7 is a diagram showing another modification of the structure in which a gap is formed in a mold portion.

Fig. 8 is a diagram showing a distribution of gap sizes in the no-load state of the 1 st die part shown in fig. 7.

Fig. 9 is a diagram showing a distribution of gap sizes at the bottom dead center of the 1 st mold part shown in fig. 7.

Fig. 10 is a diagram showing still another modification of the example shown in fig. 7.

Detailed Description

(Structure 1)

The pressing device according to the embodiment of the present invention is a pressing device for press-forming a pressing target. The pressing device includes: a 1 st die part having a 1 st working surface that contacts one surface of the pressing object during press forming; a 2 nd die part having a 2 nd working surface which is in contact with the other surface of the pressing object at the time of press forming; a 1 st support portion that supports the 1 st mold portion; and a 2 nd support portion that supports the 2 nd die portion and is capable of reciprocating in a pressing direction with respect to the 1 st support portion. At least one of the 1 st die part and the 2 nd die part has a gap of non-uniform size in the pressing direction in at least part of an overlapping region where the 1 st processing surface and the 2 nd processing surface overlap when viewed from the pressing direction in a non-loaded state.

In the press forming by the press apparatus, the pressing target is disposed between the 1 st working surface of the 1 st die portion and the 2 nd working surface of the 2 nd die portion. The 1 st machined surface and the 2 nd machined surface (hereinafter, may be simply referred to as machined surfaces) have shapes corresponding to the target shapes of the press-formed articles. The 1 st support portion and the 2 nd support portion are relatively close in the pressing direction, so that the press-formed object is press-formed between the 1 st die portion and the 2 nd die portion. In press forming, the 1 st working surface is in contact with one surface of the object to be pressed, and the 2 nd working surface is in contact with the other surface of the object to be pressed on the side opposite to the one surface. The shape of the press-formed product is determined by the shape of the space (gap) between the 1 st working surface and the 2 nd working surface at the closest state of the 1 st die portion and the 2 nd die portion, i.e., at the bottom dead center. The shape of the processed surface may not necessarily be the same as the target shape of the press-formed product. For example, a shape different from the target shape of the press-formed product may be a shape of the processed surface in consideration of the amount of elastic deformation after pressing such as springback (elastic recovery).

In the above configuration 1, the pressing device is provided with a gap having a non-uniform size in the pressing direction in at least one of the 1 st die portion and the 2 nd die portion (hereinafter, there is a case of simply referred to as a die portion) in the non-load state in an overlapping region overlapping the work surface when viewed from the pressing direction. At the time of press forming, at least one of the 1 st support portion and the 2 nd support portion (hereinafter, there is a case where the support portion is simply referred to as a "support portion") may be deflected by a press load. The mold portion is deformed by the deflection of the support portion. The inventors found the following: by providing the uneven gap in the die portion in the unloaded state, deformation of the die portion due to deflection of the support portion during press forming can be absorbed by the uneven gap. Therefore, by providing uneven gaps in the die portion in the unloaded state as described above, deformation of the die portion due to deflection of the support portion in press forming can be reduced. As a result, deformation of the working surface of the mold portion due to deflection of the support portion can also be reduced. In this way, the influence of the deflection of the support portion of the die on the press forming can be reduced with a simple structure. The influence on press forming may be, for example, a crack, a wrinkle, or a forming defect such as a decrease in the shape accuracy of a press-formed product.

The no-load state is a state in which no pressing load is applied to the mold portion. The gap provided in at least one of the 1 st die part and the 2 nd die part may be a gap between the 1 st die part and the 1 st support part or a gap between the 2 nd die part and the 2 nd support part, or may be a gap inside the 1 st die part or the 2 nd die part. The gap in the 1 st or 2 nd mold portion may be, for example, a gap between a plurality of members constituting the 1 st or 2 nd mold portion. In this way, the gap can be set as a gap between two adjacent members among the members constituting the mold portion or the members in contact with the mold portion. That is, the above-described gap is provided between the surface of one of the two adjacent members and the surface of the other member opposed to the surface. The adjacent two members may be both members constituting the mold portion, or may be members constituting the support portion that is in contact with the mold portion. As an example, the gap in the no-load state may be a gap between a convex surface protruding in the pressing direction of one of the two adjacent members and a plane of the other member opposite to the convex surface.

In the above configuration 1, at least one of the 1 st die portion and the 2 nd die portion may have a gap in which a dimension in a pressing direction in a no-load state at least a part of an overlapping region in which the 1 st processing surface and the 2 nd processing surface overlap when viewed from the pressing direction is uneven in two directions orthogonal to each other when viewed from the pressing direction. In this case, the minimum dimension in the pressing direction in the no-load state of the gap at the inner region on the inner side of the center line, which is a set of midpoints of line segments connecting the center of gravity of the overlapping region and an arbitrary position of the outer edge of the overlapping region, may be smaller than the minimum dimension in the pressing direction in the no-load state of the gap at the outer region on the outer side of the center line. This reduces the influence of the deflection of the support portion of the die on the press forming with a simple structure. For example, when the 1 st support portion and the 2 nd support portion are deflected such that they are recessed in a bowl shape in the pressing direction centering on the 1 st die portion and the 2 nd die portion, the deflection can be efficiently absorbed by utilizing the gap.

The outer edge of the overlapping region as viewed from the pressing direction becomes a closed line (loop shape). Therefore, the central line, which is a set of midpoints of lines connecting the center of gravity and any point of the outer edge, becomes a closed line (loop shape). Further, the minimum dimension of the pressing direction of the gap in each of the inner region and the outer region is the dimension of the pressing direction of the gap at the point where the dimension of the pressing direction of the gap in each of the inner region and the outer region is minimum.

The minimum dimension of the pressing direction of the gap in the no-load state at the inner region may be smaller than the minimum dimension of the gap in the pressing direction in the no-load state at the outer region in two directions orthogonal to each other when viewed from the pressing direction. This makes it possible to more efficiently absorb the deflection of the bowl shape centered on the 1 st die part and the 2 nd die part by using the gap. For example, the minimum size of the gap in the non-loaded state of the inner region may be smaller than the minimum size of the gap in the non-loaded state of the outer region in both the long side direction and the short side direction of the overlap region.

(Structure 2)

In the above configuration 1, the amount of deformation of the gap of the overlap region at the bottom dead center in the pressing direction with respect to the gap of the overlap region in the no-load state may be larger than the amount of deformation of the 1 st machined surface and the 2 nd machined surface at the bottom dead center in the pressing direction with respect to the 1 st machined surface and the 2 nd machined surface in the no-load state. This reduces the influence of the deflection of the support portion of the die on the press forming with a simple structure.

For example, the gap in the no-load state may be configured such that the shape of the 1 st machining surface and the 2 nd machining surface in the no-load state is the same as the shape of the 1 st machining surface and the 2 nd machining surface at the bottom dead center. In addition, in the form in which the shape of the 1 st processing surface and the 2 nd processing surface in the no-load state is the same as the shape of the 1 st processing surface and the 2 nd processing surface at the bottom dead center, the shape is also included in the case where the degree to which the influence on the shape accuracy of the press-formed product can be ignored is slightly changed.

(Structure 3)

The minimum dimension of the gap in the press direction in the forming surface region in which the 1 st and 2 nd working surfaces in the overlap region contribute to displacement of the pressing target in the press forming may be smaller than the minimum dimension of the gap in the press direction in the peripheral region outside the forming surface region. In this way, the influence of the deflection of the support portion of the die on the press forming in the region centered on the forming surface of the die can be reduced efficiently.

(Structure 4)

In any one of the above structures 1 to 3, at least one of the 1 st mold portion and the 2 nd mold portion may include: in the unloaded state, the size of the gap inside the overlap region in the pressing direction is smaller than the size of the gap outside the overlap region in the pressing direction.

The inventors found the following: by making the gap inside the region overlapping the 1 st working surface and the 2 nd working surface smaller than the gap of the outer edge of the region overlapping the 1 st working surface and the 2 nd working surface when viewed from the pressing direction, deformation of the mold portion due to deflection of the support portion can be easily absorbed by the gap. By reducing the gap of the inner portion with respect to the gap of the outer edge portion of the region overlapping the working surface as in the above-described configuration 4, the deformation of the mold portion caused by the deflection of the support portion can be further reduced.

(Structure 5)

In any one of the above structures 1 to 4, the gap may be provided by at least one of a surface of the 1 st mold portion facing the 1 st support portion and a surface of the 2 nd mold portion facing the 2 nd support portion. Thus, a gap that absorbs deformation due to deflection of the support portion can be provided at a position of the mold portion near the support portion.

(Structure 6)

In the above configuration 5, at least one of the concave-convex surface of the 1 st mold portion facing the 1 st support portion and the concave-convex surface of the 2 nd mold portion facing the 2 nd support portion may include: in the unloaded state, the portion has a greater degree of protrusion in the pressing direction inside the overlap region as viewed in the pressing direction than the outer edge of the overlap region. Thereby, the deformation of the mold portion caused by the deflection of the support portion can be further reduced.

For example, at least one of the surface of the 1 st mold portion facing the 1 st support portion and the surface of the 2 nd mold portion facing the 2 nd support portion may include an inclined surface as follows: in the no-load state, the inclined surface protrudes to a greater extent as it enters from the outer edge of the overlap region inward when viewed from the pressing direction.

(Structure 7)

In any one of the above structures 1 to 6, the gap may be provided by at least one of an insertion plate inserted between the 1 st mold portion and the 1 st support portion and an insertion plate inserted between the 2 nd mold portion and the 2 nd support portion. Thus, a gap that absorbs deformation due to deflection of the support portion can be provided at a position of the mold portion near the support portion. In addition, the form of the gap can be easily changed by replacing the insertion plate. The insertion plate may be, for example, an insertion plate having a non-uniform thickness.

(Structure 8)

In the above configuration 7, at least one of the insert plate inserted between the 1 st mold portion and the 1 st support portion and the insert plate inserted between the 2 nd mold portion and the 2 nd support portion may include: in the unloaded state, the thickness of the portion inside the overlap region is larger than the thickness of the outer edge of the overlap region when viewed from the pressing direction. Thereby, the deformation of the mold portion caused by the deflection of the support portion can be further reduced.

For example, at least one of the insert plate inserted between the 1 st mold portion and the 1 st support portion and the insert plate inserted between the 2 nd mold portion and the 2 nd support portion may include: in the no-load state, the thickness of the portion becomes larger as it enters from the outer edge of the overlap region inward when viewed from the pressing direction. For example, the insertion plate may include an inclined surface inclined so that the thickness thereof increases as the insertion plate enters from the outer edge of the overlapping region.

(Structure 9)

In any one of the above 1 to 8, at least one of the 1 st mold portion and the 2 nd mold portion may have: a machined surface portion including the 1 st machined surface or the 2 nd machined surface; and a base for mounting the machined surface portion. In this case, the gap may be provided between the processing surface portion and the base portion in at least one of the 1 st die portion and the 2 nd die portion. The gap may be provided by a surface of the machined surface portion facing the base portion or by a concave-convex surface of the base portion facing the machined surface portion. Thus, a gap for absorbing deformation due to deflection of the support portion can be provided at a position of the die portion close to the working surface. Therefore, deformation of the processed surface that affects the shape accuracy of the press-formed product is easily reduced.

(Structure 10)

In the above configuration 9, the surface of the machined surface portion facing the base portion or the surface of the base portion facing the machined surface portion may have the following irregularities: in the unloaded state, the portion has a greater degree of protrusion in the pressing direction inside the overlap region as viewed in the pressing direction than the outer edge of the overlap region. Thereby, the deformation of the mold portion caused by the deflection of the support portion can be further reduced.

For example, the surface of the machined surface portion facing the base portion or the surface of the base portion facing the machined surface portion may include the following inclined surface: in the no-load state, the inclined surface protrudes to a greater extent as it enters from the outer edge of the overlap region inward when viewed from the pressing direction.

(Structure 11)

In any one of the above structures 1 to 10, at least one of the 1 st mold portion and the 2 nd mold portion may have: a machined surface portion including the 1 st machined surface or the 2 nd machined surface; and a base for mounting the machined surface portion. The gap may be provided in at least one of the 1 st die part and the 2 nd die part by an insert plate interposed between the processing surface part and the base part. Thus, a gap for absorbing deformation due to deflection of the support portion can be provided at a position of the die portion close to the working surface. In addition, the form of the gap can be easily changed by replacing the insertion plate. The insertion plate may be, for example, an insertion plate having a non-uniform thickness.

(Structure 12)

In the above configuration 11, the insertion plate to be inserted between the machined surface portion and the base portion may include: in the unloaded state, the thickness of the portion inside the overlap region is larger than the thickness of the outer edge of the overlap region when viewed from the pressing direction. Thereby, the deformation of the mold portion caused by the deflection of the support portion can be further reduced.

For example, the insertion plate to be inserted between the machined surface portion and the base portion may include: in the no-load state, the portion becomes thicker as it enters from the outer edge of the overlap region inward when viewed from the pressing direction. For example, the insertion plate may include an inclined surface inclined so that the thickness thereof increases as the insertion plate enters from the outer edge of the overlapping region.

(manufacturing method)

A method of manufacturing a press-formed article using a press apparatus is also included in the embodiment of the present invention. The manufacturing method of the embodiment of the present invention includes the following steps: a step of disposing a pressing target between a 1 st die part supported by a 1 st support part and a 2 nd die part supported by a 2 nd support part of the pressing device; and bringing the 1 st support portion and the 2 nd support portion into relative close contact with each other in the pressing direction, bringing the 1 st working surface of the 1 st die portion into contact with one surface of the object to be pressed, bringing the 2 nd working surface of the 2 nd die portion into contact with the other surface of the object to be pressed, and performing press forming. At least one of the 1 st die portion and the 2 nd die portion has a gap in which the dimension of the pressing direction in the no-load state of at least part of an overlapping region in which the 1 st processing face and the 2 nd processing face overlap when viewed from the pressing direction is uneven in two directions orthogonal to each other when viewed from the pressing direction. In the press forming, the dimension of the gap in the press direction at least at part of the region is nearly uniform as compared with that in the no-load state. Further, the manufacturing method can be performed using any one of the pressing devices of the above structures 1 to 12.

According to the above manufacturing method, by providing the uneven gap to the mold portion in the unloaded state, the deformation of the mold portion due to the deflection of the support portion during press forming can be absorbed by the uneven gap. As a result, deformation of the working surface of the mold portion due to deflection of the support portion can also be reduced. In this way, the influence of the deflection of the support portion of the die on the press forming can be reduced with a simple structure.

In the above-described structure, the gap may be formed in a shape of a circular cross section, and the width of the gap may be smaller in a direction along the longitudinal direction and the lateral direction of the overlapping region in the unloaded state as viewed from the pressing direction.

The amount of change in the dimension of the gap in the pressing direction of the forming surface region at the bottom dead center with respect to the dimension of the gap in the pressing direction of the forming surface region in the no-load state may be larger than the amount of change in the shape of the 1 st machined surface and the 2 nd machined surface at the bottom dead center with respect to the shape of the 1 st machined surface and the 2 nd machined surface in the no-load state.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The same reference numerals are given to the same or corresponding parts in the drawings, and the description thereof will not be repeated. In the drawings referred to below, the structure is simplified or schematically shown, or some constituent members are omitted, for ease of understanding of the description.

Embodiment(s)

Fig. 1 is a side view showing a configuration example of a pressing device according to the present embodiment. The pressing device 1 shown in fig. 1 includes a 1 st die part 2, a 2 nd die part 3, a 1 st support part 4, a 2 nd support part 5, a frame 6, and a slider driving part 7.

The 1 st support portion 4 is a pad, for example. The 1 st support portion 4 supports the 1 st mold portion 2. That is, the 1 st mold portion 2 is attached and fixed to the 1 st support portion 4. The 1 st die part 2 has a 1 st machined surface 2a. The 1 st working surface 2a is in contact with one surface of the pressing object W during press forming. The shape of the 1 st processed surface 2a may be the same as the target shape of the press-formed product. Alternatively, the shape of the 1 st processed surface 2a may be a shape obtained by subtracting the amount of elastic deformation of press forming such as springback (elastic recovery) from the target shape of the press formed product.

The 2 nd support portion 5 is a slider (ram), for example. The 2 nd support portion 5 supports the 2 nd mold portion 3. That is, the 2 nd mold portion 3 is attached and fixed to the 2 nd support portion 5. The 2 nd die part 3 has a 2 nd working surface 3a. The 2 nd working surface 3a is in contact with the other surface (the surface on the opposite side to the one surface) of the pressing object W at the time of press forming. The shape of the 2 nd working surface 3a may be the same as the target shape of the press-formed product. Alternatively, the shape of the 2 nd working surface 3a may be a shape obtained by subtracting the amount of elastic deformation of press forming such as springback (elastic recovery) from the target shape of the press formed product.

The 2 nd support portion 5 is reciprocable in the pressing direction with respect to the 1 st support portion 4. In the example shown in fig. 1, the 1 st support portion 4 is fixed to the frame 6. The 2 nd support portion 5 is mounted so as to be capable of reciprocating in the pressing direction with respect to the frame 6. In fig. 1, the pressing direction is indicated by an arrow P. The slider driving section 7 reciprocates the 2 nd support section 5 with respect to the frame 6 in the pressing direction. The driving method of the slider driving unit 7 can be, for example, mechanical or hydraulic. Examples of the mechanism include a crank mechanism, a toggle mechanism, and a link mechanism. As an example of the hydraulic slider driving unit 7, a slider driving unit having a hydraulic cylinder can be given. In addition, the slider driving section may be configured to perform driving control using a servo motor in both the mechanical and hydraulic cases.

In the example shown in fig. 1, the frame 6 includes a base on which the 1 st support portion 4 (pad) is placed, a column extending upward from the base, and a cross member that is erected on the column. A slider driving section 7 is disposed between the cross member and the 2 nd support section 5.

Fig. 1 shows a pressing device 1 in a no-load state. In the no-load state, the 1 st mold portion 2 has a gap S1, and the 2 nd mold portion 3 has a gap S2. The dimensions of the gaps S1, S2 in the pressing direction in the no-load state are at least partially uneven in the overlap region R1 overlapping the 1 st machined surface 2a and the 2 nd machined surface 3a when viewed from the pressing direction.

The gaps S1 and S2 can be formed as spaces between convex surfaces protruding in the pressing direction or concave surfaces recessed in the pressing direction of the constituent members of the pressing device and surfaces of the constituent members of the pressing device opposite (facing) the convex surfaces or the concave surfaces, which are perpendicular to the pressing direction.

In the example shown in fig. 1, the dimensions in the pressing direction of the gaps S1, S2 in the center portion of the overlap region R1 are smaller than the dimensions in the pressing direction of the gaps S1, S2 in the end portions of the overlap region R1. The dimensions of the gaps S1, S2 in the pressing direction gradually decrease from the outer edge of the overlap region R1 toward the inside. That is, the dimensions of the gaps S1 and S2 in the pressing direction are smallest at the center of the overlap region R1, and become larger as they approach the end from the center of the overlap region R1. In this way, the gaps S1 and S2 preferably have portions that decrease as they enter from the outer edge of the overlap region R1 toward the inside. This makes it easy to absorb the deformation of the 1 st die part 2 and the 2 nd die part 3 caused by the deflection of the 1 st support part 4 and the 2 nd support part 5 during press forming by the gaps S1 and S2.

Fig. 1 is a side view as seen from a direction perpendicular to the longitudinal direction of the overlapping region. Fig. 1 shows the shape of the gaps S1, S1 in the longitudinal direction. In the example shown in fig. 1, in the longitudinal direction of the overlap region R1, the minimum size in the pressing direction of the gaps S1, S2 in the inner region R1u located inward from the center of gravity G and the outer edge E1 of the overlap region R1 is smaller than the minimum size in the pressing direction of the gaps S1, S2 in the outer region R1S located outward from the center of gravity G and the outer edge E1. Although not shown, the minimum dimensions of the gaps S1 and S2 in the inner region R1u are smaller than the minimum dimensions of the outer region R1S in the short side direction of the overlap region R1. By configuring the gaps S1 and S2 in the unloaded state in this way, the gaps S1 and S2 can efficiently absorb the deflection of the pressing device 1, and the deformation of the 1 st machined surface 2a and the 2 nd machined surface 3a at the bottom dead center can be suppressed. The long side direction and the short side direction are examples of two directions orthogonal to each other when viewed from the pressing direction.

In the example shown in fig. 1, the minimum dimensions in the pressing direction of the gaps S1 and S2 in the forming surface region R2 are smaller than the minimum dimensions in the pressing direction of the gaps S1 and S2 in the peripheral region R3 outside the forming surface region R2. The forming surface region R2 is a region of the overlap region R1 in which the 1 st machined surface 2a and the 2 nd machined surface 3a contribute to displacement of the pressing object in the pressing direction in the press forming. The forming surface region R2 is a region included in the overlap region R1 when viewed from the pressing direction. In the forming surface region R2, at the bottom dead center, the pressing object is displaced in the pressing direction in accordance with the shapes of the 1 st processed surface 2a and the 2 nd processed surface 3 a. By configuring the gaps S1 and S2d in the unloaded state in this way, the gaps S1 and S2 can efficiently absorb the deflection of the pressing device 1, and the deformation of the 1 st machined surface 2a and the 2 nd machined surface 3a at the bottom dead center can be suppressed.

In the case of manufacturing a press-formed article using the press apparatus 1, first, a pressing object is arranged between the 1 st die part 2 and the 2 nd die part 3. Next, the 2 nd support portion 5 is brought closer to the 1 st support portion 4 by the slider driving portion 7. Until the 2 nd die portion 3 reaches the bottom dead center, the 2 nd support portion 5 moves. At the bottom dead center, the 1 st working surface 2a of the 1 st die portion 2 is in contact with one surface of the pressing object W, and the 2 nd working surface 3a of the 2 nd die portion 3 is in contact with the other surface of the pressing object W.

Fig. 2 is a view showing a state in which the 2 nd die portion 3 of the pressing device 1 shown in fig. 1 is positioned at the bottom dead center. At the bottom dead center, a pressing load is applied from the 1 st support portion 4 and the 2 nd support portion 5 to the 1 st die portion 2 and the 2 nd die portion 3. The reaction force acts on the 1 st support portion 4 and the 2 nd support portion 5 from the 1 st mold portion 2 and the 2 nd mold portion 3. The 1 st support portion 4 and the 2 nd support portion 5 are deflected by the reaction force. The 1 st die part 2 and the 2 nd die part 3 are also deformed due to their flexing.

In the example shown in fig. 2, at the bottom dead center, the 1 st die part 2 and the 2 nd die part 3 deform so as to fill the gaps S1, S2 in the unloaded state. The gaps S1a, S2a at the bottom dead center are narrower than the gaps S1, S2 in the no-load state. The dimensions of the gaps S1 and S2 in the pressing direction in the no-load state are changed in a nearly uniform manner in the press forming as compared with the case of the no-load state. That is, the gaps S1 and S2 in the unloaded state deform so as to absorb the deformation of the 1 st die part 2 and the 2 nd die part 3 during press forming. This can reduce deformation of the 1 st machined surface 2a of the 1 st die part 2 and the 2 nd machined surface 3a of the 2 nd die part 3 due to deflection of the 1 st support part 4 and the 2 nd support part 5 during press forming.

In the example shown in fig. 1 and 2, the amount of deformation in the pressing direction of the gaps S1, S2 of the overlap region R1 at the bottom dead center with respect to the gaps S1, S2 of the overlap region R1 in the no-load state is larger than the amount of deformation in the pressing direction of the 1 st machined surface 2a and 2 nd machined surface 3a at the bottom dead center with respect to the 1 st machined surface 2a and 2 nd machined surface 3a in the no-load state. In this way, the gaps S1 and S2 in the no-load state are formed so that the shapes of the 1 st machined surface 2a and the 2 nd machined surface 3a at the bottom dead center are substantially the same as those of the 1 st machined surface 2a and the 2 nd machined surface 3a in the no-load state.

If the 1 st support portion 4 and the 2 nd support portion 5 are deflected by the pressing load, the 1 st mold portion 2 and the 2 nd mold portion 3 coupled thereto are deflected similarly. As a result, deformation due to deflection may occur also in the 1 st working surface 2a of the 1 st die part 2 and the 2 nd working surface 3a of the 2 nd die part 3. The shape of the press-formed article is determined by the shape of the space (gap) between the 1 st machined surface 2a and the 2 nd machined surface 3a at the bottom dead center. Therefore, the deformation of the 1 st machined surface 2a and the 2 nd machined surface 3a causes a reduction in formability such as cracks and wrinkles in the press-formed product and in the shape accuracy of the press-formed product.

In the above example, the deflection of the 1 st support portion 4 and the 2 nd support portion 5 of the press apparatus 1 during press forming can be absorbed by the gaps S1, S2 of the 1 st mold portion 2 and the 2 nd mold portion 3 in the no-load state. This can reduce the amount of deformation of the working surface of the die portion, which is the contact portion with the material. As a result, the shape accuracy of the press-formed product can be improved.

In the example shown in fig. 1, the gap S1 is provided inside the 1 st mold portion 2, and the gap S2 is provided inside the 2 nd mold portion 3. As a modification, the gap S1 may be provided between the 1 st mold portion 2 and the 1 st support portion 4, as will be described later. The gap S2 may be provided between the 2 nd mold portion 3 and the 2 nd support portion 5. The gaps S1 and S2 may be formed by providing irregularities on the surfaces of the 1 st mold portion 2 and the 2 nd mold portion 3. Alternatively, the gaps S1 and S2 may be formed by insert plates inserted into the 1 st mold portion 2 and the 2 nd mold portion 3.

In the example shown in fig. 1, the 1 st die part 2 has a base 21 and a processing surface 22. The machined surface 22 includes a 1 st machined surface 2a. The machined surface portion 22 is attached to the base portion 21. The base 21 is attached to the 1 st support 4. The 2 nd die part 3 has a base 31 and a machined surface 32. The machined surface portion 32 includes a 2 nd machined surface 3a. The machined surface portion 32 is attached to the base portion 31. The base 31 is attached to the 2 nd support 5.

The machined surface portions 22, 32 are insert molds, for example. The bases 21, 31 are, for example, insert receiving portions. The insert receiving portion has, for example, a recess recessed in the pressing direction. In this case, the insert mold is fixed in a state of being inserted into the concave portion of the insert receiving portion. The insert receiving portion is not limited to a structure for receiving the insert mold by the recess.

In the example shown in fig. 1, the gap S1 is formed by the irregularities of the surface of the processing surface portion 22 provided in the 1 st mold portion 2 facing the base portion 21. The gap S2 is formed by the irregularities of the surface of the processing surface portion 32 provided in the 2 nd die portion 3 facing the base portion 31. The irregularities of the machined surface portions 22, 32 are convex toward the base portions 21, 31. The surfaces of the base portions 21, 31 facing the machined surface portions 22, 32 are planes perpendicular to the pressing direction.

As a modification, the gaps S1 and S2 may be formed by irregularities of the surfaces of the base portions 21 and 31 facing the machined surface portions 22 and 32. In this case, the irregularities of the base portions 21, 31 may be convex surfaces protruding in the pressing direction. In this case, the surfaces of the machined surface portions 22, 32 facing the base portions 21, 31 are planes perpendicular to the pressing direction.

In this way, the gaps S1 and S2 in the no-load state can be set as gaps between the member having the convex surface protruding in the pressing direction and the member having the flat surface opposing the convex surface. In this case, when a pressing load is applied, the protruding portion of the convex surface comes into contact with the opposing surface first, and receives the load. Thereby, the deflection caused by the pressing load is easily absorbed by the gap.

Fig. 3 is a diagram showing a modification of the structure in which the gaps S1 and S2 are formed in the 1 st mold portion 2 and the 2 nd mold portion 3. In the example shown in fig. 3, a gap S1 is provided in the 1 st die part 2 by an insertion plate 23 having a non-uniform thickness interposed between the machined surface part 22 and the base part 21. That is, the gap S1 is formed by a space between the insert plate 23 and the machined surface portion 22 or the base portion 21. The 2 nd die part 3 is provided with a gap S2 by an insertion plate 33 having a non-uniform thickness interposed between the machined surface part 32 and the base part 31. That is, the gap S2 is formed by the space between the insert plate 33 and the machined surface portion 32 or the base portion 31.

The thickness of the insertion plates 23, 33 is the thickest at the center portion, and becomes thinner as approaching the peripheral edge from the center portion. The insertion plates 23, 33 have a convex lens shape. One face of the insertion plate 23, 33 is a flat face, and the other face on the opposite side to the one face is a convex curved face. In this way, the insertion plates 23 and 33 may include portions having a smaller thickness near the end portions of the overlap region R1 than at the inner side of the overlap region R1 away from the end portions. This can further reduce deformation of the 1 st machined surface 2a and the 2 nd machined surface 3a caused by deflection of the 1 st support portion 4 and the 2 nd support portion 5. The insertion plates 23, 33 are disposed so as to protrude toward the 1 st working surface 2a and the 2 nd working surface 3 a. In contrast, the insertion plates 23, 33 may be arranged so as to protrude in a direction away from the 1 st working surface 2a and the 2 nd working surface 3 a.

Fig. 4 is a plan view of the 1 st die part 2 shown in fig. 3 viewed from the pressing direction (upward). In fig. 4, the insertion plate 23 is shown in broken lines. In the example shown in fig. 4, the insert plate 23 has substantially the same shape as the 1 st processed surface 2a when viewed from the pressing direction. That is, the insert plate 23 is provided so as to overlap the entire region overlapping the 1 st working surface 2a when viewed in the pressing direction. The insertion plate 23 may be provided so as to overlap at least partially with the region overlapping the 1 st working surface 2 a. The insertion plate 23 may be provided so as to include the entire region overlapping the 1 st working surface 2 a. For example, the insert plate 23 may be provided in a range including the 1 st processed surface 2a and larger than the 1 st processed surface 2a when viewed in the pressing direction. Similarly, the insertion plate 33 may be provided so as to overlap the entire 2 nd working surface 3a when viewed from the pressing direction, or may be provided so as to overlap at least partially.

The entirety of the 1 st processed surface 2a overlaps with the 2 nd processed surface 3a when viewed from the pressing direction. Therefore, in the example of fig. 4, the outer edge of the 1 st machined surface 2a becomes the outer edge of the overlap region R1. The insertion plate 23 is overlapped with the entirety of the overlap region R1. When viewed in the pressing direction, the region of the overlap region R1 located inward of the center line between the center G and the outer edge is an inner region R1u, and the region located outward of the center line is an outer region R1s. In fig. 4, a center line between the center of gravity G and the outer edge is indicated by a one-dot chain line AR. The center line between the center of gravity G and the outer edge of the overlap region R1 is a set of midpoints of line segments connecting the center of gravity G and any point of the outer edge.

In fig. 4, a line 2aR represents the outer edge of the forming surface region R2. In the forming surface region R2, any one of the 1 st machined surface 2a and the 2 nd machined surface 3a has a shape that is convex or concave in the pressing direction.

Fig. 5 is a diagram showing a distribution of dimensions in the pressing direction of the gap S1 in the no-load state in the 1 st die part 2 shown in fig. 4. Fig. 6 is a diagram showing a distribution of sizes of the gap S1 at the bottom dead center in the pressing direction. In fig. 5, the contour lines are indicated by broken lines, and the contour lines indicate positions where the dimensions of the gap S1 in the pressing direction in the no-load state are equal. Contours are shown at every 0.025mm difference. In fig. 5 and 6, the range of each size of the gap S1 is indicated with different hatching. The smaller size range is indicated by the denser shading. The area where the hatching is the most dense represents an area where the dimension of the gap S1 in the pressing direction is 0 to 0.025 mm.

In the example shown in fig. 5, the entire gap S1 formed by the insertion plate 23 in the no-load state is formed such that the gap S1 in the inner region R1u is smaller than the gap S1 in the outer region R1S. The closer to the outside from the center of gravity G, the larger the gap S1. As a result, the minimum size of the pressing-direction gap S1 in the inner region R1u is smaller than the minimum size of the pressing-direction gap S1 in the outer region R1S in both the long-side direction and the short-side direction of the overlap region R1. In this way, by providing the gradient of the gap S1 in both the long-side direction and the short-side direction (i.e., in the two directions orthogonal to each other when viewed from the pressing direction), the deflection of the pressing device can be absorbed efficiently. The longitudinal direction of the overlap region R1 is the direction in which the dimension is longest when viewed from the pressing direction. The short side direction is a direction perpendicular to the long side direction when viewed from the pressing direction. In fig. 4 to 6, the x-direction is the long-side direction, and the y-direction is the short-side direction.

In the example shown in fig. 5, in the no-load state, the size of the gap S1 in the peripheral region R3 in the pressing direction is larger than the size of the gap S1 in the forming surface region R2 in the pressing direction. The minimum dimension in the pressing direction of the gap S1 at the forming surface region R2 is smaller than the minimum dimension in the pressing direction of the gap S1 at the peripheral region R3 outside the forming surface region R2. This structure can be seen in both the long-side direction and the short-side direction of the overlap region. This allows the gap S1 to efficiently absorb deflection caused by the difference between the displacement of the molding surface region of the pressing device and the displacement of the peripheral region.

In the example shown in fig. 6, the gap S1 is 0 to 0.025mm in the entire overlapping region R1 at the bottom dead center. That is, at the bottom dead center, the gap S1 is small and nearly uniform in both the outer region R1S and the inner region R1u as compared with the no-load state.

The shape of the gaps S1, S2 is determined by the shape of the insertion plates 23, 33. The shape of the gaps S1, S2 can be changed by replacing the insertion plates 23, 33 with insertion plates of different shapes. By providing the gaps S1 and S2 by the insertion plates 23 and 33, the shapes of the gaps S1 and S2 can be easily changed. Thus, for example, the gaps S1 and S2 can be formed in a shape more suitable for reducing deformation due to deflection by using a trial-and-error method.

Fig. 7 is a diagram showing another modification of the structure in which the gaps S1 and S2 are formed in the 1 st mold portion 2 and the 2 nd mold portion 3. In the example shown in fig. 7, a gap S1 is provided between the 1 st mold portion 2 and the 1 st support portion 4. The gap S2 is provided between the 2 nd mold portion 3 and the 2 nd support portion 5. The gap S1 is provided by the irregularities of the surface of the 1 st mold part 2 facing the 1 st support part 4. The gap S1 is a space between the 1 st die part 2 and the 1 st support part 4. The surface of the 1 st support portion 4 facing the 1 st die portion 2 is a plane perpendicular to the pressing direction. The gap S2 is provided by the irregularities of the surface of the 2 nd mold portion 3 facing the 2 nd support portion 5. The gap S2 is a space between the surface having the irregularities of the 2 nd mold portion 3 and the 2 nd support portion 5. The surface of the 2 nd support portion 5 opposed to the 2 nd die portion 3 is a plane perpendicular to the pressing direction.

The concave-convex surface of the 1 st mold portion 2 facing the 1 st support portion 4 includes the following portions: in the no-load state, the protruding degree in the pressing direction of the inner side of the overlap region R1 overlapping the 1 st machined surface 2a and the 2 nd machined surface 3a when viewed from the pressing direction is larger than the protruding degree in the pressing direction of the outer edge of the overlap region R1. The surface roughness of the 2 nd mold portion 3 facing the 2 nd support portion 5 includes the following portions: in the unloaded state, the protruding degree in the pressing direction of the inner side of the overlapping region R1 of the portion is larger than the protruding degree in the pressing direction of the outer edge of the overlapping region R1. This can further reduce deformation of the 1 st machined surface 2a and the 2 nd machined surface 3a caused by deflection of the 1 st support portion 4 and the 2 nd support portion 5.

Fig. 8 is a diagram showing a distribution of dimensions in the pressing direction of the gap S1 in the no-load state in the 1 st die part 2 shown in fig. 7. Fig. 9 is a diagram showing a distribution of sizes of the gap S1 at the bottom dead center in the pressing direction. In fig. 8, the contour lines (dots) of the gap S1 are shown at every 0.05mm gap. In fig. 8 and 9, the most dense hatching indicates that the dimension of the gap S1 in the pressing direction is in the range of 0 to 0.05 mm.

In the example shown in fig. 8, the size of the gap S1 in the outer region R1S in the overlap region R1 in the pressing direction is larger than the size of the gap S1 in the inner region R1u in the pressing direction. In addition, in the overlapping region R1 and the region outside thereof, the size of the outside gap S1 is larger than the size of the inside gap S1. That is, the gap S1 tends to be larger as it goes outward from the center of gravity G. The minimum size of the gap S1 at the overlap region R1 is smaller than the minimum size of the gap S1 at the region outside the overlap region R1. In this way, the deflection of the pressing device can be absorbed by the gap S1 in the 1 st machined surface 2a, the 2 nd machined surface 3a, and the regions outside thereof.

In the example shown in fig. 8, the gap S1 in the peripheral region R3 is larger than the gap S1 in the molding surface region R2. The minimum dimension of the gap S1 in the pressing direction at the forming surface region R2 is smaller than the minimum dimension of the gap S1 in the peripheral region R3. The outer edge of the peripheral region R3 is the outer edge of the base 21. In the peripheral region R3, too, the gap S1 tends to be smaller as it goes from the outer edge to the inner side. This tendency can be seen in both the long-side direction and the short-side direction.

In the example shown in fig. 9, the gap S1 is 0 to 0.05mm in the entire overlapping region R1 at the bottom dead center. That is, at the bottom dead center, the gap S1 is small and nearly uniform as compared with the no-load state in the two regions of the overlap region R1 and the region outside thereof.

Fig. 10 is a diagram showing still another modification of the example shown in fig. 7. In the example shown in fig. 10, the gap S1 is provided by the insertion plate 23 inserted between the 1 st mold portion 2 and the 1 st support portion 4. That is, the gap S1 is formed by the space between the insertion plate 23 and the 1 st support portion 4. The gap S2 is provided by the insertion plate 33 interposed between the 2 nd mold portion 3 and the 2 nd support portion 5. That is, the gap S2 is formed by the space between the insertion plate 33 and the 2 nd support portion 5.

The thickness of the insertion plates 23, 33 is the thickest at the center portion, and becomes thinner as approaching the peripheral edge from the center portion. The insertion plates 23, 33 have a convex lens shape. The surface of the insert plates 23, 33 contacting the mold portion is a flat surface, and the other surface on the opposite side to the flat surface is a convex curved surface. In this way, the insertion plates 23 and 33 may include portions having a smaller thickness near the end portions of the overlap region R1 than at the inner side of the overlap region R1 away from the end portions. This can further reduce deformation of the 1 st machined surface 2a and the 2 nd machined surface 3a caused by deflection of the 1 st support portion 4 and the 2 nd support portion 5.

(analysis results)

The press molding simulation was performed using data obtained by modeling the press apparatus, and the shape accuracy of the press molded product was analyzed. As the analysis model, a model (model 1) of a pressing device having the insertion plates 23, 33 and the gaps S1, S2 having the structure shown in fig. 3 and a model (model 2) of a pressing device having a structure in which the insertion plates 23, 33 and the gaps S1, S2 are not provided in fig. 3 were used for simulation. In both the mold 1 and the mold 2, the frame 6, the support portions 4 and 5, and the mold portions 2 and 3 are each made of an elastic material that deforms elastically. The simulation was also performed on a model (model 3) having the same shape as the model 2 and having the entirety of the mold portions 2 and 3 as a rigid body. As a result of the simulation, the shape of the press-formed article was obtained. The shape of the press-formed article of the mold 1, 2 was compared with the shape of the press-formed article of the mold 3. Specifically, the difference in accuracy obtained by digitizing the difference between the shapes of the press-formed products of the models 1 and 2 and the press-formed product of the model 3 was calculated.

As a result of the analysis, the difference in precision of the press-formed product of the mold 1 provided with the insert plate became about half of the difference in precision of the press-formed product of the mold 2 not provided with the insert plate. As is clear from this, the shape accuracy of the press-formed product can be improved by providing the insert plate to form the gap in the no-load state. In addition, the following was confirmed: in the case of the model 1, the deflection of the 1 st machined surface 2a, 2 nd machined surface 3a of the die at the press working bottom dead center is small compared with the case of the model 2. As is clear from this, by providing the insert plate to form the gap in the no-load state, the deflection of the machined surface can be reduced, and the reduction in the shape accuracy of the press-formed product due to the deflection can be improved.

The embodiments of the present invention have been described above. The press apparatus 1 of the present embodiment can be used as a press apparatus for press forming a metal pressing object, for example. As an example, the press apparatus 1 may be used as a press apparatus for pressing an object from a steel material (ultra-high strength steel sheet) having an ultra-high strength (tensile strength of 780MPa or more). There is a tendency that: the shape accuracy defect caused by the deformation of the working surface of the die due to the deflection of the support portion of the press apparatus becomes remarkable particularly in press forming of a press-target member having high strength. Therefore, the press apparatus 1 and the manufacturing method according to the present embodiment can be suitably applied to press forming of high-strength steel materials.

The pressing device of the present embodiment is not limited to this, and can be applied to, for example, a pressing device having a pressing load of 10 to 2000 tonf. In particular, the press apparatus according to the present embodiment can be used for a press apparatus having a press load of 100tonf or more. In this case, the influence of the deflection on the dimensional accuracy of the press-formed product of the ultra-high strength steel material can be suppressed.

The present invention is not limited to the above-described embodiments. For example, in the above example, the insertion plates 23, 33 are plates having uneven thickness, but the thickness of the insertion plates 23, 33 may be uniform. In this case, for example, both the portion where the insertion plates 23, 33 are arranged and the portion where the insertion plates 23, 33 are not arranged may be provided in the overlap region R1. In this case, too, gaps S1, S2 having uneven dimensions in the pressing direction can be formed in the overlap region R1.

In the example shown in fig. 1, the 1 st support portion 4 is fixed to the frame 6 and the 2 nd support portion 5 is moved in the pressing direction with respect to the frame 6, but the structure in which the 2 nd support portion 5 reciprocates in the pressing direction with respect to the 1 st support portion 4 is not limited to this. For example, the 2 nd support portion 5 may be fixed to the frame 6, and the 1 st support portion 4 may reciprocate with respect to the frame. Alternatively, both the 1 st support portion 4 and the 2 nd support portion 5 may be configured to reciprocate in the pressing direction with respect to the frame 6.

In the example shown in fig. 1, the 1 st processed surface 2a includes a convex portion protruding in the pressing direction, and the 2 nd processed surface 3a includes a concave portion recessed in the pressing direction. That is, the 1 st die part 2 is a punch, and the 2 nd die part 3 is a die. In contrast, the 1 st die part 2 may be a die, and the 2 nd die part 3 may be a punch. In addition, the mold portions may be provided in addition to the 1 st mold portion and the 2 nd mold portion. For example, in the press apparatus for performing drawing forming, a die section such as a press ring may be provided as an auxiliary die section in addition to the 1 st die section and the 2 nd die section.

In the example shown in fig. 1, the 1 st die part 2 and the 2 nd die part 3 are each composed of a plurality of members, i.e., a machined surface part and a base part. In contrast, at least one of the 1 st die part 2 and the 2 nd die part 3 may be integrally formed of 1 member. In this case, a gap is provided between the mold portion and the support portion, which are integrally formed of 1 member.

In the example shown in fig. 1, 1 st mold part is attached to 1 st support part 4, and 1 st mold part 2 is attached to 2 nd support part. In contrast, a plurality of 1 st mold portions may be mounted on the 1 st support portion 4, and a plurality of 2 nd mold portions may be mounted on the 2 nd support portion. In this case, for example, press molding by a multi-station die can be performed as follows: the press-formed object, which is press-formed by 1 of the plurality of mold sections of the 1 support section, is moved to the other mold section, and press-formed again.

In the example shown in fig. 1, gaps S1 and S2 are provided in both the 1 st mold portion 2 and the 2 nd mold portion 3. In contrast, the following configuration may be adopted: one of the 1 st die part 2 and the 2 nd die part 3 is provided with a gap, and the other is not provided with a gap. In this case, too, an effect of reducing the deformation of the mold portion caused by the deflection of the support portion can be obtained.

While the above description has been given of an embodiment of the present invention, the above embodiment is merely an example for carrying out the present invention. Accordingly, the present invention is not limited to the above-described embodiments, and can be implemented by appropriately modifying the above-described embodiments within a range not departing from the gist thereof.

Description of the reference numerals

1. A pressing device; 2. a 1 st mold section; 3. a 2 nd mold section; 4. a 1 st support part; 5. a 2 nd support part; 21. 31, a base; 22. 32, processing the face; 23. 33, an insert plate; s1, S2 and gaps; w, pressing the object; r1, overlap region; r1u, inner region; r1s, outside region.

Claims

1. A press apparatus for press-forming a press-target member, wherein,

the pressing device comprises:

a 1 st die part having a 1 st working surface that contacts one surface of the pressing object during press forming;

a 2 nd die part having a 2 nd working surface which is in contact with the other surface of the pressing object at the time of press forming;

a 1 st support portion that supports the 1 st mold portion; and

a 2 nd support portion that supports the 2 nd die portion and is capable of reciprocating in a pressing direction with respect to the 1 st support portion,

at least one of the 1 st die portion and the 2 nd die portion has a gap in which the dimension of the pressing direction in the no-load state at least part of an overlapping region in which the 1 st processing face and the 2 nd processing face overlap when viewed from the pressing direction is uneven in two directions orthogonal to each other when viewed from the pressing direction,

The minimum dimension in the pressing direction in the no-load state of the gap at the inner region on the inner side of the center line, which is a set of midpoints of line segments connecting the center of gravity of the overlapping region and an arbitrary position of the outer edge of the overlapping region, is smaller than the minimum dimension in the pressing direction in the no-load state of the gap at the outer region on the outer side of the center line.

2. The pressing apparatus of claim 1, wherein,

the amount of deformation of the gap of the overlap region at the bottom dead center in the pressing direction with respect to the gap of the overlap region in the no-load state is larger than the amount of deformation of the 1 st machined surface and the 2 nd machined surface at the bottom dead center in the pressing direction with respect to the 1 st machined surface and the 2 nd machined surface in the no-load state.

3. Pressing device according to claim 1 or 2, wherein,

the minimum dimension in the pressing direction of the gap at a forming surface region of the overlap region where the 1 st and 2 nd processed surfaces contribute to displacement in the pressing direction of the pressing object in press forming is smaller than the minimum dimension in the pressing direction of the gap at a peripheral region outside the forming surface region.

4. A pressing apparatus according to any one of claims 1 to 3, wherein,

at least one of the 1 st and 2 nd mold portions comprises the following portions: in the unloaded state, the size of the gap inside the overlap region in the pressing direction is smaller than the size of the gap outside the overlap region in the pressing direction.

5. The pressing apparatus according to any one of claims 1 to 4, wherein,

the gap is provided by at least one of the concave-convex of the surface of the 1 st mold part facing the 1 st support part and the concave-convex of the surface of the 2 nd mold part facing the 2 nd support part.

6. A pressing apparatus according to claim 5, wherein,

at least one of the irregularities of the surface of the 1 st mold portion facing the 1 st support portion and the irregularities of the surface of the 2 nd mold portion facing the 2 nd support portion includes: in the unloaded state, the portion has a greater degree of protrusion in the pressing direction inside the overlap region as viewed in the pressing direction than the outer edge of the overlap region.

7. The pressing apparatus according to any one of claims 1 to 6, wherein,

the gap is provided by at least one of an insert plate inserted between the 1 st mold portion and the 1 st support portion and an insert plate inserted between the 2 nd mold portion and the 2 nd support portion.

8. The pressing apparatus of claim 6, wherein,

at least one of an insert plate inserted between the 1 st mold portion and the 1 st support portion and an insert plate inserted between the 2 nd mold portion and the 2 nd support portion includes: in the unloaded state, the thickness of the portion inside the overlap region is larger than the thickness of the outer edge of the overlap region when viewed from the pressing direction.

9. The pressing apparatus according to any one of claims 1 to 8, wherein,

at least one of the 1 st mold portion and the 2 nd mold portion has: a machined surface portion including the 1 st machined surface or the 2 nd machined surface; and a base for mounting the processing face portion,

the gap is provided between the processing face portion and the base portion in at least one of the 1 st die portion and the 2 nd die portion, and,

The gap is provided by the surface of the machined surface portion facing the base portion or the surface of the base portion facing the machined surface portion.

10. The pressing apparatus of claim 9, wherein,

the surface of the machined surface portion opposite to the base portion or the concave-convex surface of the base portion opposite to the machined surface portion includes the following portions: in the unloaded state, the portion has a greater degree of protrusion in the pressing direction inside the overlap region as viewed in the pressing direction than the outer edge of the overlap region.

11. The pressing apparatus according to any one of claims 1 to 10, wherein,

the gap is provided in at least one of the 1 st die part and the 2 nd die part by an insert plate interposed between the processing surface part and the base part.

12. The pressing apparatus of claim 11, wherein,

an insert plate inserted between the machined face portion and the base portion includes: in the unloaded state, the thickness of the portion inside the overlap region is larger than the thickness of the outer edge of the overlap region when viewed from the pressing direction.

13. A method for producing a press-formed article by using a press apparatus, wherein,

the method for producing the press-formed product comprises the following steps:

a step of disposing a pressing target between a 1 st die part supported by a 1 st support part and a 2 nd die part supported by a 2 nd support part of the pressing device; and

bringing the 1 st support portion and the 2 nd support portion into relatively close contact with each other in the pressing direction, bringing the 1 st working surface of the 1 st die portion into contact with one surface of the object to be pressed, bringing the 2 nd working surface of the 2 nd die portion into contact with the other surface of the object to be pressed, performing press forming,

the minimum dimension in the pressing direction in the unloaded state of the gap at the inner region of the inner side of the center line, which is a set of midpoints of line segments connecting the center of gravity of the overlapping region and an arbitrary position of the outer edge of the overlapping region,

At the time of the press forming, the size of the gap in the press direction at least at part of the overlap region is nearly uniform as compared with that in the no-load state.