Mold structure, pressure processing device and pressure processing method

Abstract

A mold structure, pressure processing device, and pressure processing method are disclosed, which can reduce the impact of unstable positioning accuracy caused by the press body, eliminate the need for adjustment of the pressure processing device by a skilled person, have excellent productivity, and are easy to install and disassemble relative to the press body. The mold structure (1) includes a lower mold (3) fixed on a fixed table (2); an upper mold (4) disposed above the lower mold (3); a first elastic body (11) and a stop (10) disposed between the upper mold (4) and the lower mold (3); and a pressure adjustment device (6) connected to the movable table (5) of the upper mold (4). When the pressure processing is not pressurized, the first elastic body (11) separates the upper mold (4) and the lower mold (3). When the pressure processing is pressurized, the stop (10) specifies the bottom dead center position of the upper mold and applies pressure from the movable table (5) to the upper mold (40) through the pressure plate (7) of the pressure adjustment device (6) via the second elastic body (8), thereby clamping the material (30) to be processed between the upper mold (4) and the lower mold (3) for pressurization.

Description

Technical Field

[0001] This invention relates to a mold structure for pressure processing, a pressure processing apparatus using the mold structure, and a pressure processing method. Background Technology

[0002] In various electronic devices, home appliances, industrial machinery, automobiles, and communication peripherals, metal connector terminals and conductive rods (hereinafter collectively referred to as connector terminals) are used to electrically connect multiple circuit components.

[0003] For example, in the significantly increased production of hybrid and electric vehicles in recent years, connector terminals function as relays, resistors, fuses, and power sensors, serving as crucial components for the supply, disconnection, and distribution of high-voltage power. Looking ahead, to cope with further increases in voltage and to improve safety and convenience, the number of electronic components housed within power supply units is expected to rise. Consequently, connector terminals will also need to meet the demands of higher density, requiring connector terminals manufactured with greater precision.

[0004] The manufacturing of connector terminals is generally carried out by pressure processing of thin sheet metal materials. Various pressure processing methods are known, including single-pass pressure processing and sequential feed pressure processing. In the simplest single-pass pressure processing method, molds are prepared separately for each step, such as shearing, bending, and stretching. Because each step requires the removal and insertion of the workpiece, the more steps a product has, the longer the manufacturing time becomes, leading to lower production efficiency. On the other hand, sequential feed pressure processing, with multiple processing steps within a single mold, automatically feeds the workpiece sequentially to the next step during each pressure processing operation, eliminating the need for material removal and insertion relative to the mold. Therefore, sequential feed pressure processing is the fastest and most efficient pressure processing method, suitable for mass production.

[0005] If connector terminals that have undergone micro-machining are mass-produced, then stable, high-precision machining is required. Here, "high-precision machining" means micro-machining of the workpiece material in a manner that keeps it within the target error range and within a specified range of dimensional changes over time after production. Machining accuracy is influenced by both the precision of the mold design itself and the positioning accuracy of the upper and lower dies that constitute the mold. Furthermore, as the requirements for micro-machining of connectors gradually increase, the impact of the positioning accuracy of the upper and lower dies becomes relatively greater, making its improvement an important issue. Factors affecting the positioning accuracy of the upper and lower dies include wear of the press body, wobbling of the sliding parts, and expansion and contraction of the housing due to temperature changes. Consequently, the bottom dead center position of the movable stage may be unstable, and the pressure relative to the workpiece material (hereinafter referred to as "machining force") may become unstable. Here, bottom dead center refers to the moment when the upper and lower dies are closest, and the bottom dead center position refers to the position of the upper and lower dies at that moment of closest approach. In addition, the main body of a press refers to the part of a pressure processing device other than the mold, such as the movable table, fixed table, housing and other mechanical parts.

[0006] In bending processes performed by a pressure processing device, after the material to be processed is bent, there is a phenomenon called springback, where the angle becomes larger than the desired angle immediately after processing. As a countermeasure against springback, the introduction of pressure processing devices with highly controlled functions (hereinafter referred to as servo presses) can be cited.

[0007] Because it is difficult to predict the factors affecting the positioning accuracy of the upper and lower dies through calculation, the mold height adjustment and mold correction of the pressure processing device are carried out on-site by skilled technicians based on their experience and correction. Here, mold height refers to the distance between the bottom dead center of the movable table and the vertical distance between the fixed table of the pressure processing device.

[0008] Various methods have been proposed to improve the positioning accuracy of the upper and lower dies. For example, as a press that improves positioning accuracy and shortens the optimal position detection time, it is known that a buffer pressure cylinder installed between the upper and lower dies of the press is used to buffer the hammering pressure generated by the press during the processing of raw materials.

[0009] Furthermore, even if the stroke of the moving table, cam, etc., operated by the drive assembly changes due to heat, inertial forces during start-up and shutdown, the loading assembly can absorb the change in stroke, maintaining the applied pressure at a specified pressure and improving machining accuracy. As such a pressure device, a pressure device with a free clamping method is known where the punch plate on which the die is mounted is not directly connected to a displacement working member such as a rod or cam that is lifted and lowered by the drive assembly, but is supported by a loading assembly (see Patent Document 2).

[0010] Prior art literature

[0011] Patent documents

[0012] Patent Document 1: Japanese Patent Application Publication No. 10-58200

[0013] Patent document 2: Japanese Patent No. 5038172 Summary of the Invention

[0014] The problem that the invention aims to solve

[0015] However, in the press described in Patent Document 1, since the upper die and the movable table are fixed, the buffering effect produced by the buffer pressure cylinder can be considered limited when excessive pressure is applied to the workpiece from the movable table due to factors such as the expansion and contraction of the shell caused by temperature changes.

[0016] In the pressure device described in Patent Document 2, a movable table equipped with a first loading component is fixed to the upper frame, and a base plate equipped with a punching die and a second helical spring is fixed to the lower frame. During the manufacture of this pressure device, the parallelism between the movable table and the base plate needs to be precisely adjusted so that when the upper frame descends, the rod on the movable table side applies vertical pressure to the punching plate on the base plate side. Furthermore, when disassembling the die structure, both the upper and lower frames need to be disassembled, making die structure replacement difficult.

[0017] Furthermore, servo presses effective against springback have limitations, such as the inability to increase processing speed or obtain the required processing force. Therefore, the applicability of servo presses is limited, and compared to conventional pressure processing equipment, there is a risk of reduced productivity.

[0018] Furthermore, with the increasing difficulty in securing skilled personnel, there is a shortage of technicians skilled in areas such as mold height adjustment and mold modification. Additionally, the transfer of technical expertise is becoming increasingly challenging. Therefore, shifting from traditional processing methods that rely on technician skills to those that do not is a major challenge in the pressure industry.

[0019] This invention was made in view of the above-mentioned circumstances, and its object is to provide a mold structure that can reduce the impact of unstable positioning accuracy caused by the press body, eliminates the need for adjustments to the pressure processing device by a skilled technician, offers excellent productivity, and facilitates installation and disassembly relative to the press body. Furthermore, its object is to provide a pressure processing apparatus and method using this mold structure.

[0020] The present invention discloses a mold structure for pressure processing of a workpiece, disposed between a movable table and a fixed table of a press body. The mold structure comprises a lower mold fixed to the fixed table; an upper mold disposed above the lower mold; a first elastic body and a stop disposed between the upper and lower molds; a pressure adjusting device connected to the movable table side of the upper mold, the pressure adjusting device having a pressure plate abutting against the movable table; and a second elastic body disposed between the pressure plate and the upper mold. During non-pressurized pressure processing, the first elastic body separates the upper and lower molds. During pressurized pressure processing, the stop, while defining the bottom dead center position of the upper mold, applies pressure from the movable table to the upper mold via the pressure plate of the pressure adjusting device and the second elastic body, thereby clamping the workpiece between the upper and lower molds.

[0021] The upper end face of the second elastic body abuts against the lower surface of the pressure plate in a non-fixed manner.

[0022] The second elastic body mentioned above is a fluid spring. Furthermore, the fluid spring has a housing, a fluid sealed inside the housing, and a piston rod that can extend and retract axially within the housing. The upper end face of the piston rod abuts against the underside of the pressure plate in a non-fixed manner, and pressure is applied axially from the pressure plate relative to the piston rod within the housing.

[0023] The mold structure described above has components that suppress changes in the speed and acceleration of the upper mold.

[0024] The pressure processing apparatus of the present invention is characterized by comprising the above-described mold structure; a fixed stage for fixing the lower mold of the mold structure; and a movable stage for abutting the pressure plate of the mold structure.

[0025] The pressure processing method of the present invention uses the above-described mold structure to perform pressure processing on the work-bearing material. Its characteristic is that, after the work-bearing material is placed on the lower mold, the lower mold, in a state where the first elastic body is separated from the lower mold, is lowered by the pressure of the movable stage under the pressure of the pressure adjustment device, and positioned at the target bottom dead center by the stopper. With the upper mold positioned, the movable stage pushes the second elastic body of the pressure adjustment device to shrink while descending to the bottom dead center of the descending stage. During the period from when the movable stage changes to an upward stroke until the compression of the second elastic body is released, the work-bearing material is clamped between the upper mold and the lower mold for a predetermined time for pressure processing by having the upper mold remain at the target bottom dead center.

[0026] Here, the target bottom dead center position of the upper die means the bottom dead center position of the upper die that can apply the most suitable processing force to the material being processed.

[0027] The effects of the invention

[0028] The mold structure of the present invention is for pressure processing of workpieces by being arranged between a movable table and a fixed table of a press body. It includes a lower mold fixed to the fixed table; an upper mold disposed above the lower mold; a first elastic body and a stop disposed between the upper and lower molds; a pressure adjusting device connected to the movable table side of the upper mold, the pressure adjusting device having a pressure plate abutting against the movable table; and a second elastic body disposed between the pressure plate and the upper mold. During non-pressurized pressure processing, the first elastic body separates the upper and lower molds. During pressurized pressure processing, the stop, while defining the bottom dead center position of the upper mold, applies pressure from the movable table to the upper mold via the pressure plate of the pressure adjusting device and the second elastic body, clamping the workpiece between the upper and lower molds. Therefore, installation and removal relative to the press body are easy. Thus, the adjustment of the pressure processing device by a skilled technician, as required in conventional pressure processing devices, is eliminated. Furthermore, compared to conventional pressure processing devices, even with a short time for the movable table to move up and down once, it can maintain its position at the bottom dead center of the upper die for a longer period of time (hereinafter referred to as bottom dead center time). Therefore, unlike servo presses, it does not cause a drop in processing speed and force, significantly reducing springback and resulting in excellent productivity. On this basis, the flattening stability relative to the thickness direction of the material is improved.

[0029] Since the upper end face of the second elastic body is in contact with the lower part of the pressure plate in a non-fixed manner, it is not easy to transmit the force in the direction of thrust to the second elastic body when the pressure plate is slightly offset, and strain of the second elastic body can be prevented.

[0030] Since the second elastic body is a fluid spring, it has better characteristics in damping vibrations caused by the press body, and can further reduce the impact of unstable positioning accuracy caused by the press body.

[0031] Furthermore, the aforementioned fluid spring includes a housing, fluid sealed inside the housing, and a piston rod that can extend and retract axially within the housing. The upper end face of the piston rod abuts against the lower surface of the pressure plate in a non-fixed manner, and pressure is applied from the pressure plate relative to the piston rod in the axial direction (vertical direction) of the housing. Therefore, even if the pressure plate experiences slight misalignment, it is less likely to transmit a force in the direction of thrust to the piston rod, preventing leakage of the internal fluid of the fluid spring to the outside due to piston rod tilting or other reasons. As a result, the performance of the pressure regulating device is prevented from deteriorating.

[0032] Because the aforementioned mold structure includes components that suppress changes in the speed and acceleration of the upper mold, it can drastically reduce and attenuate the rebound force from the workpiece during stamping, suppress high-acceleration motion, and prevent the stopper from colliding with high acceleration. This, in turn, mitigates noise during pressure processing.

[0033] The pressure processing apparatus of the present invention includes the above-described mold structure; a fixed stage for fixing the lower mold of the mold structure; and a movable stage for abutting the pressure plate of the mold structure. Therefore, compared with conventional pressure processing apparatuses, it eliminates the need for adjustments to the mold height and other aspects of the pressure processing apparatus by a skilled technician, enabling high-precision processing regardless of the technician's skill level.

[0034] The pressure processing method of the present invention uses the aforementioned mold structure to pressure process the workpiece. After the workpiece is placed on the lower mold, the lower mold, which is in a state where the first elastic body is separated from the lower mold, is lowered by the pressure of the movable stage under the pressure of the pressure adjustment device. It is then positioned at the target bottom dead center by the stopper. With the upper mold positioned, the movable stage pushes the second elastic body of the pressure adjustment device to shrink while descending to the bottom dead center of the descending stage. During the period from when the movable stage changes to an upward stroke until the compression of the second elastic body is released, the workpiece is clamped between the upper and lower molds for a predetermined time for pressure processing by the upper mold remaining at the target bottom dead center. Therefore, the bottom dead center time of the upper mold can be extended, significantly reducing springback. Furthermore, the flattening stability relative to the thickness direction of the material is improved. Additionally, if the movable stage shifts position, the pressure adjustment device can absorb the shift, reducing the impact of unstable positioning accuracy and enabling high-precision processing. Attached Figure Description

[0035] Figure 1 This is a side view of the mold structure (when not being machined) of the present invention.

[0036] Figure 2 This is a side view of the mold structure (during processing) of the present invention.

[0037] Figure 3 This is a top view of the pressure regulating device from above.

[0038] Figure 4 This is a cross-sectional view of a fluid spring, which is an example of a second elastic body.

[0039] Figure 5 This is a three-dimensional view of connector terminals that have undergone pressure processing.

[0040] Figure 6 It is a side view of the mold structure with suppression components.

[0041] Figure 7 This is a diagram showing the track of a conventional pressure processing device.

[0042] Figure 8 The formula represents a diagram of the processing force of a conventional pressure processing device.

[0043] Figure 9 This is a diagram showing the track of the pressure processing apparatus of the present invention.

[0044] Figure 10 This is a diagram showing the processing force of the pressure processing apparatus of the present invention. Detailed Implementation

[0045] In order to implement the invention

[0046] based on Figure 1 and Figure 2 An example of the mold structure of the present invention will be described. Figure 1 and Figure 2 This is a side view of the mold structure of the present invention viewed from the side, orthogonal to the direction of travel of the material being processed. Figure 1 This indicates the state when not being processed. Figure 2 This indicates the state during processing.

[0047] like Figure 1 and 2As shown, the mold structure 1 includes a lower mold 3 fixed on a fixed platform 2; an upper mold 4 disposed above the lower mold 3; a first elastic body 11 and a stopper 10 disposed between the upper mold 4 and the lower mold 3; and a pressure adjustment device 6 connected to the movable platform 5 side of the upper mold 4. Here, the fixed platform 2 and the movable platform 5 are not included in the structure of the mold structure of the present invention, but are part of the pressure processing device on which the mold structure 1 can be mounted.

[0048] exist Figure 1 During the non-pressurized pressure processing shown, the first elastomer causes the upper mold 4 and the lower mold 3 to separate. Figure 2 During the pressure processing shown, while the stopper 3 specifies the bottom dead center position of the upper die 4, pressure from the movable table 5 is applied to the upper die 4 via the pressure plate 7 of the pressure adjustment device 6 and the second elastic body 8, and the material to be processed 30 is clamped between the upper die 4 and the lower die 3 to apply pressure.

[0049] The lower die 3 includes a metal plate 3a supporting the workpiece 30 and a metal plate 3b fixed on the fixed table 2. The metal plate 3a is the die plate, and the metal plate 3b is the back plate. The upper die 4 includes a metal plate 4a positioned directly below the pressure adjusting device 6 and a metal plate 4b positioned below the metal plate 4a. The metal plate 4a is the back plate. The metal plate 4b includes a punch plate and a stop plate (not shown) positioned below it. A punch 14 protrudes from below the metal plate 4b to press the workpiece 30 from above. The punch 14 presses the workpiece 30 through the punch head hole of the stop plate. A recess 15 is provided on the upper surface of the metal plate 3a, facing the punch 14 in the vertical direction. The punch 14 presses the workpiece 30 by clamping it between the recess 15 and pressing it, thus shaping the workpiece 30 into a predetermined shape.

[0050] The pressure adjustment device includes a pressure plate 7 that abuts against the movable platform 5, a second elastic body 8, and a limiting member 13. The second elastic body 8 is disposed between the pressure plate 7 and the upper mold 4. The pressure plate 7 and the movable platform 5 only abut against each other and are not fixed. In this invention, because the structure is designed to place the pressure adjustment device 6 on the upper part of the upper mold 4, when the upper mold 4 is fixed to the movable platform 5, it is necessary to fix the pressure plate 7 of the pressure adjustment device 6 to the movable platform 5. In its construction, fixing is not easy. Even if the mold structure 1 is not fixed to the upper mold 4 (pressure plate 7) and the movable platform 5, since the lower mold 3 is fixed to the fixed platform 2 while the upper part of the pressure plate 7 is pressed vertically against the lower part of the movable platform 5, the mold structure 1 does not experience positional displacement.

[0051] based on Figure 3 The relationship between the pressure adjustment device 6 and the upper mold is explained. Figure 3 This is a top view of the pressure regulating device from above the pressure plate. (For example...) Figure 3 As shown, a limiting member 13 is provided on the side of the pressure plate 7, which slides freely and abuts against the side of the metal plate 4a of the upper mold disposed below the pressure plate 7. The limiting member 13 is provided on all four sides of the pressure plate 7, which forms a quadrilateral when viewed from above. The pressure plate 7 and the metal plate 4a have the same shape when viewed from above. The four limiting members 13, by abutting against the four sides of the upper mold 4 without gap, can prevent the horizontal positional relationship between the pressure adjusting device 6 and the upper mold 4 from shifting. Thus, since the lower part of the pressure plate 7 and the upper part of the metal plate 4 only repeatedly approach and separate in the vertical direction, the pressure from the pressure plate 7 is applied vertically relative to the upper part of the metal plate 4 via the second elastic body 8. In addition to the above-mentioned limiting member, the horizontal positional relationship between the pressure adjusting device and the upper mold can be maintained in a certain way by other guiding members or the like, without the need for the limiting member.

[0052] exist Figure 3 In this configuration, because the pressure from the movable stage is applied evenly to the upper part of the upper mold, 11 second elastic bodies 8 (indicated by dashed lines) are arranged at predetermined intervals. Here, "upper part of the upper mold" means... Figure 2 On top of metal plate 4a. Figure 3 As described above, horizontal movement is restricted on the pressure plate 7 and the upper mold. However, the pressure plate 7 and the upper mold are not fixed in the vertical direction by a second elastic body. Therefore, while the pressure plate 7 is movable in the vertical direction relative to the upper mold, it is connected by multiple anti-detachment parts 16 in a manner that prevents it from falling off. The anti-detachment parts 16 are provided in a way that maintains the vertical distance between the lower surface of the pressure plate 7 and the upper surface of the upper mold within a predetermined range. Thus, the lower surface of the pressure plate 7 and the upper surface of the upper mold can approach and move away parallel and unchanged. Furthermore, the inserting member 12c penetrates the pressure plate 7 in the vertical direction and is provided at four locations at predetermined intervals, with guide rods restricting horizontal movement of the mold structure.

[0053] based on Figure 4 The construction of the fluid spring used as a second elastic body will be explained. Figure 4 This is a cross-sectional view of a fluid spring, which is an example of a second elastic body.

[0054] like Figure 4 As shown, the second elastic body 8 has a housing 8; a fluid 19 sealed inside the housing 8; and a piston rod 17 that can extend and retract axially (in the XY direction) of the housing 8, which is a spring utilizing the elasticity of the fluid. By using a fluid spring as the second elastic body, the impact of unstable positioning accuracy caused by the press body can be reduced because it can dampen vibrations caused by the press body.

[0055] Furthermore, the second elastic body is not limited to fluid springs; various elastic bodies such as metal springs and rubber springs can be selected. The most suitable spring can be selected based on factors such as component cost and required characteristics. Fluid springs are preferred as the second elastic body due to their excellent damping characteristics. The fluid used as the fluid spring can be selected from, for example, oil, air, nitrogen, etc. In this invention, since a high elastic modulus is required as the second elastic body, a fluid such as nitrogen gas sealed under high pressure is preferred. Furthermore, the number and arrangement of the second elastic bodies can be appropriately set and are not limited to... Figure 1 Structures such as...

[0056] use Figure 1 The arrangement of the second elastic body will be described. The upper end face of the second elastic body 8 abuts against the lower surface of the pressure plate 7. In particular, it is preferable that the upper end face of the second elastic body 8 and the lower surface of the pressure plate 7 are not fixed by bolts or the like. Figure 4 In the case of such a fluid spring, the upper end face of the piston rod can be made to abut against the lower surface of the pressure plate 7 in a non-fixed manner, and pressure can be applied axially from the pressure plate 7 relative to the piston rod in the housing. A recess is provided on the upper surface of the upper mold, and the upper mold 4 and the second elastic body 8 are positioned by fitting the lower end of the second elastic body 8 into this recess. Here, even if the lower end of the second elastic body is firmly fixed, the fit is only loose. Here, for positioning, a recess can also be provided on the lower surface of the pressure plate, so that the upper end of the second elastic body fits into this recess with a gap.

[0057] The horizontal positional relationship between the pressure plate and the upper die in the pressure adjustment device is maintained in a certain manner by limiting members, but slight misalignment may occur. Therefore, by making the above-described structure (non-fixed), it is not easy to transmit the force in the thrust direction to the piston rod of the second elastic body, and the pressure applied from the pressure plate to the second elastic body is applied only in the vertical direction (up and down direction) along the long axis of the second elastic body. As a result, strain of the second elastic body can be prevented. In particular, when the second elastic body is a fluid spring, leakage of the internal fluid of the fluid spring to the outside due to the tilting of the piston rod can be prevented. As a result, it is easy to maintain the performance of the pressure adjustment device and the influence of unstable positioning accuracy caused by the press body can be reduced over a long period of time. In addition, by not fixing the second elastic body to the pressure plate and the upper die, the replacement of the elastic body is easy, thus reducing the time and labor required for design changes.

[0058] A first elastic body 11 and a stop 10 are provided between the upper mold 4 and the lower mold 3. The stop 10 defines the bottom dead center position of the upper mold 4 when pressure is applied. The stop 10 includes an upper stop 10a and a lower stop 10b disposed at a position where it collides with the upper stop 10a. The upper stop 10a is disposed below the metal plate 4a of the upper mold 4, and the lower stop 10b is disposed above the metal plate 3b of the lower mold 3. The number and arrangement of the stops (a pair of upper and lower stops) can be appropriately set and are not limited to a specific configuration. Figure 1 The structure.

[0059] The first elastic body 11 is a metal helical spring used to separate the upper mold 4 and lower mold 3 when no pressure is applied. Eight first elastic bodies 11 are arranged at predetermined intervals along the outer periphery of the mold structure when viewed from above (illustration omitted). The elastic coefficient of the second elastic body 8 is greater than that of the first elastic body 11. When pressure is applied to the workpiece 30, the first elastic body 11 lifts both the upper mold 4 and the pressure adjustment device 6 as the movable table 5 rises from the bottom dead center. At this time, the top of the pressure plate 7 and the bottom of the movable table 5 do not separate.

[0060] Furthermore, if the first elastic body is an elastic body, it can be selected from metal springs, fluid springs, and rubber springs, etc. As the first elastic body, a metal helical spring is preferred due to its excellent cost-effectiveness and ability to ensure a large amount of deformation. Additionally, the number and arrangement of the first elastic bodies 11 can be appropriately set and are not limited to [specific types]. Figure 1 The structure.

[0061] like Figure 1 and 2 As shown, in the pressure processing apparatus equipped with the mold structure 1 of the present invention, pressure is applied to the upper mold 4 via the pressure plate 7 as the movable stage 5 descends, causing the upper mold 4 to descend. At this time, the deformation of the first elastic body 11 is greater than the deformation of the second elastic body 8. If the upper mold 4 descends and approaches the lower mold 3, the upper stop 10a and the lower stop 10b collide, and the upper mold 4 reaches the target bottom dead center position by the stop whose length has been pre-adjusted. The movable stage 5 descends further, while the upper mold 4 remains at the target bottom dead center position. The movable stage 5 deforms only the second elastic body 8, displacing the pressure adjustment device 6 downwards as it descends to the bottom dead center position of the movable stage 5.

[0062] During the descent of the movable stage 5, the upper die 4 is continuously subjected to pressure from the movable stage 5 via the pressure plate 7. While the upper die 4 remains at the target bottom dead center position due to the rebound force from the stopper 10, the second elastic body 8 absorbs the pressure from the movable stage 5 and deforms, thus reducing the pressure exerted from the movable stage 5 on the stopper 10. Then, the movable stage 5 rises, releasing the compression of the second elastic body 8. Simultaneously, the upper stopper 10a and the lower stopper 10b move away, and the upper die 4 also rises from the target bottom dead center position. Through this action, the stopper 10 is not subjected to force exceeding the specified pressure from the movable stage 5, and is less prone to breakage or deformation even with repeated pressure processing. As a result, because the bottom dead center position of the upper die 4 can be maintained at the target position for a longer period, the product quality becomes easier to keep within the target error range.

[0063] The pressure adjusting device 6, the upper mold 4, and the lower mold 3 are connected by a guide member 12. The guide member 12 consists of a guide rod 12a, an inserting member 12b, and an inserting member 12c. The guide rod 12a is arranged to pass through the pressure plate 7, the metal plate 4a, and the metal plate 3b. An inserting member 12c with an inserting hole for the guide rod 12a is provided on the pressure plate 7. Similarly, an inserting member 12b with an inserting hole for the guide rod 12a is provided on the metal plate 4a. Here, the inner surfaces of each inserting member and the outer surfaces of the guide rod 12a slide freely against each other. Therefore, the pressure adjusting device 6 can slide freely along the guide rod 12a and move freely in the vertical direction. Likewise, the upper mold 4 can also slide freely along the guide rod 12a and move freely in the vertical direction.

[0064] The mold structure may also include components to suppress changes in the speed and acceleration of the upper mold. Furthermore, these components that suppress changes in the speed and acceleration of the upper mold are called suppression components. As an example of a mold structure incorporating a suppression component, Figure 6 This indicates a mold structure with a pressure adjustment device and a suppression component. For example... Figure 6 As shown, in mold structure 1', the pressure adjustment device 6' includes a pressure plate 7, a second elastic body 8, a suppressing component 9, and a limiting member 13. Multiple suppressing components 9 are arranged at predetermined intervals between the pressure plate 7 and the upper mold 4. Oil dampers are used as suppressing components 9.

[0065] When an oil damper is used as a suppression component, its fixing method can be the same as that of the second elastic body 8 described above. Similar to the second elastic body, by making the end face of the suppression component 9 and the pressure plate 7 non-fixed, since no thrust load is applied to the suppression component, biased wear between the suppression component structural members inside the suppression component can be suppressed. Suppression of biased wear is related to reducing oil leakage from the suppression component and maintaining the performance of the pressure regulating device.

[0066] The second elastic body in the pressure regulating device uses an elastic body with a larger elastic coefficient than the first elastic body. Without a suppressor component in the die structure, during stamping, the rebound force from the workpiece material decreases sharply, causing the downward pressure from the pressure regulating device to generate a large acceleration in the upper die. The upper and lower stops collide. The force of this collision poses a risk of noise generation, affecting product accuracy, and extending maintenance life. Therefore, to suppress changes in the speed and acceleration of the upper die during stamping and to prevent the stops from colliding with high acceleration, a suppressor component is preferable.

[0067] As a suppressive property, the higher the performance of the suppressive component in inhibiting changes in the speed and acceleration of the upper die, the better it can suppress rapid changes in the speed and acceleration of the upper die. However, if the performance is too high, it will generate excessive pressure. Therefore, it is necessary to comprehensively consider the elastic coefficient of the second elastomer, the number of second elastomers, the type and number of suppressive components, and their positional relationship, so as to suppress changes in the speed and acceleration of the upper die without generating excessive pressure. In addition, the above problems can also be solved by selecting the most suitable type of second elastomer or by adding different types of elastomers without using suppressive components.

[0068] The type of damping component is not limited to oil dampers, but also includes metal dampers, rubber dampers, etc., allowing for free selection. Furthermore, the location of the damping component is not limited to between the pressure plate and the upper die; it can also be placed between the upper die itself, or between the upper and lower dies, allowing for free selection. When the damping component is placed between the upper and lower dies, for example, it can be placed parallel to the first elastic body, or the first elastic body and the damping component can be connected in series in the vertical direction between the upper and lower dies. When the damping component is placed between the upper and lower dies, it directly suppresses the speed and acceleration of the upper die because it resists the downward movement of the upper die.

[0069] As a suppressing component, a counterweight metal plate can be installed on the upper die to increase its mass. The counterweight metal plate can be installed specifically for increasing mass, or it can serve the same function by increasing the mass of the back plate, punch plate, etc. Since inertial force is proportional to mass, increasing the mass of the upper die effectively suppresses changes in its speed and acceleration. The type of metal used for the counterweight metal plate can be freely selected from lead, brass, tungsten, stainless steel, etc. Tungsten metal plates are preferred because tungsten has a high specific gravity, allowing for both improved suppressing performance and miniaturization of the die structure. On the other hand, lead metal plates are preferred because they have a relatively high specific gravity and are an inexpensive raw material, offering an excellent balance between suppressing performance and price. Thus, by installing a counterweight metal plate, changes in the speed and acceleration of the upper die can be easily suppressed, noise can be reduced, product accuracy can be improved, and maintenance life can be extended.

[0070] The following describes the method for installing the mold structure of the present invention onto the press. When installing the mold structure onto the press, only the lower mold of the mold structure is placed on the fixed platform of the press, and the lower part of the lower mold is fixed with bolts or the like, parallel to the upper part of the fixed platform. At this time, the pressure adjustment device may not be fixed to the movable platform, but rather separated from it. Next, the height of the movable platform is adjusted so that the upper part of the pressure plate and the lower part of the movable platform abut against each other at the top dead center position of the movable platform. Here, the top dead center refers to the moment when the distance between the movable platform and the fixed platform is greatest during vertical movement. The top dead center position refers to the position at the top dead center. The height adjustment of the movable platform is performed by adjusting the movable platform height adjustment unit provided on the press.

[0071] By ensuring the top of the pressure plate and the bottom of the movable stage abut at the bottom dead center of the movable stage, this abutment is maintained during the up-and-down movement of the movable stage. This prevents collision between the movable stage and the pressure plate when the movable stage descends, thus preventing vibration, noise, and energy loss. Furthermore, the adjustment for ensuring the top of the pressure plate and the bottom of the movable stage abut at the top dead center is solely for ensuring proper contact between their respective surfaces. Since this adjustment is not for positioning the upper and lower dies, mold structure changes can be easily performed even by non-skilled personnel.

[0072] The method for positioning the upper and lower dies in the mold structure of the present invention will now be described. Positioning of the upper and lower dies, i.e., defining the target bottom dead center position of the upper die, is achieved by adjusting the length of the stopper. Specifically, when the movable table of the press descends, the length of the stopper is adjusted such that the upper die stops at the target bottom dead center position, in a state where the upper and lower stoppers collide. The adjustment of the stopper length can be performed using a contact length measuring instrument, a non-contact optical shape measuring instrument, etc., and is easily performed by any skilled technician. Even without mold height adjustment performed by a skilled technician, positioning can be easily achieved, which is crucial for ensuring the availability of skilled personnel and resolving issues related to technology transfer.

[0073] In the mold structure of the present invention, a first elastic body and a stop are provided between the lower mold and the upper mold, and a pressure adjustment device is provided above the upper mold. Furthermore, the pressure processing apparatus equipped with the mold structure of the present invention is a pressure processing apparatus comprising a mold structure, a fixed table for fixing the mold structure, and a movable table movable in the vertical direction relative to the fixed table. A comparison with conventional pressure processing apparatuses will be made below, with reference to... Figures 7-10 One side explains the effects produced by making such a structure.

[0074] exist Figure 7 The diagram shows the tracks of the movable stage and the upper die in a conventional pressure processing apparatus. The track of the movable stage represents the change in position of the movable stage relative to time during one up-and-down movement of the stage, which involves lowering and then rising to press the workpiece. Similarly, the track of the upper die also represents the change in position of the upper die relative to time. Here, the solid line represents the target track, which is the track leading to the target bottom dead center position. The dashed line represents the track variation, which is the track that changes downwards from the actual bottom dead center position compared to the target bottom dead center position.

[0075] Conventional pressure processing apparatuses consist of an upper die fixed to a movable platform and a lower die fixed to a fixed platform. The movable platform descends, and the upper and lower dies apply pressure to the workpiece positioned between them, transferring the die shape onto the workpiece for processing. The pressure exerted on the workpiece, i.e., the processing force, is determined not only by the strength of the pressure apparatus but also by the positional relationship between the upper and lower dies and the workpiece. Therefore, in conventional pressure processing apparatuses, the position of the upper die is influenced by the position of the fixed movable platform. In the case of bending processing, the workpiece is subjected to processing force from the moment the upper die begins to deform it, and the processing force continuously increases until the movable platform reaches its bottom dead center, i.e., the upper die reaches its bottom dead center. At the bottom dead center, the maximum processing force is applied relative to the workpiece.

[0076] In conventional pressure processing apparatuses, where the upper die is fixed to a movable table, if the track of the movable table changes, the track of the upper die also shifts along a different track, deviating from the target track. This shift in the track of the movable table is caused by wear in the mechanism driving the movable table, wobbling of the sliding parts, ambient temperature, and expansion and contraction of the housing due to temperature changes generated by the press itself. For example, if the housing expands slightly due to a temperature increase, the track of the movable table shifts downwards compared to the target track. In this case, the track of the upper die fixed to the movable table also shifts downwards from the target track, and the lower dead center of the upper die changes position downwards compared to the target lower dead center position (see reference). Figure 7 ).

[0077] exist Figure 8 The figure represents the change in processing force relative to time on the workpiece material from the moment the movable table of a conventional pressure processing device descends, after it has been stamped, until it rises again. Here, the solid line represents the change in processing force relative to time when the movable table moves in the target track, and the dashed line represents the change in processing force relative to time when the movable table moves in a downward-shifted track.

[0078] Various problems arise when the bottom dead center position of the upper die deviates from the target bottom dead center position. For example, if the bottom dead center position of the upper die changes upwards compared to the target bottom dead center position, there is a risk of insufficient force applied to the workpiece, resulting in inadequate machining. On the other hand, if the bottom dead center position of the upper die changes downwards compared to the target bottom dead center position, because excessive machining force is applied to the workpiece and die compared to the target machining force, there is a risk of reduced machining accuracy of the workpiece, material fracture, and damage to the die (see reference). Figure 8 Therefore, if high-precision pressure processing is to be performed stably, it is desirable that the bottom dead center position of the upper die remains almost unchanged within the allowable range even if the track of the movable stage changes for some reason.

[0079] Furthermore, to ensure stable and high-precision pressure processing, it is crucial to apply the target processing force relative to the workpiece for a predetermined time. Variations in the application time of the target processing force relative to the workpiece can lead to inconsistent product quality. Therefore, not only the bottom dead center position of the upper die but also the application time of the target processing force must be kept constant. Moreover, to reduce springback and other issues, it is generally preferable to extend the application time of the target processing force.

[0080] For the reasons mentioned above, in conventional pressure processing equipment, to control the bottom dead center position of the upper die and generate the most suitable processing force during processing, the bottom dead center is positioned by adjusting the die height by a skilled technician. Specifically, after the die is mounted on the press, the die height is adjusted so that the distance between the upper and lower dies when the movable table descends to the bottom dead center position is a predetermined interval. Furthermore, in conventional pressure processing equipment, if the upper and lower dies contact at the bottom dead center, it can cause problems such as die breakage; therefore, a stop is installed for the purpose of protecting the die. In reality, since the upper and lower dies are pressure processed under conditions where they do not contact due to height adjustment, the stop functions to prevent contact between the upper and lower dies, but this is limited to situations where the bottom dead center position unexpectedly shifts.

[0081] exist Figure 9 The text refers to the tracks of the movable stage and the upper mold in the pressure processing apparatus equipped with the mold structure of the present invention. The meanings of the movable stage track, the upper mold track, the target track, and the variable track are... Figure 7 same.

[0082] exist Figure 10 The text describes the change in processing force relative to time on the workpiece material during the pressing process, from the lowering of the movable table of the pressure processing apparatus equipped with the mold structure of the present invention until its retraction. Figure 8 Similarly, solid lines represent the change of machining force relative to time when the movable stage moves in the target track. Dashed lines represent the change of machining force relative to time when the movable stage moves in a changing track.

[0083] In the mold structure of this invention, the stop is not intended to protect the mold, but rather to position the bottom dead center of the upper mold. When not under pressure, the upper mold is lifted by a first elastic body disposed between it and the lower mold (see reference). Figure 1 As the movable stage descends, it pushes down the pressure adjustment device and the upper die. The upper die, upon colliding with the lower end of the upper stop and the upper end of the lower stop, is positioned at the target bottom dead center (refer to...). Figure 2 and Figure 9 ).

[0084] After the upper and lower stops collide, the movable stage, while pushing the second elastic body of the pressure adjustment device to shrink, descends to the bottom dead center position of the movable stage. Then, the movable stage changes its upward stroke. The upper die remains at the target bottom dead center position until the movable stage changes to its upward stroke and the upper and lower stops disengage. Thus, the bottom dead center position of the upper die is defined by the stops at the target bottom dead center position. Therefore, even if the bottom dead center position of the movable stage changes downward, the pressure device absorbs the change and does not apply excessive pressure to the stops (see reference). Figure 10 ).

[0085] In conventional pressure processing devices, the bottom dead center position of the upper die is adjusted by the die height of the movable stage. In contrast, in the die structure of this invention, the bottom dead center position of the upper die is determined by the collision of the upper and lower stoppers, thus eliminating the need for die height adjustment. This facilitates the assurance of skilled workers and the resolution of technical transmission issues. By using the die structure of this invention, even without die height adjustment, the deviation of the upper die from the target bottom dead center position can be controlled within a few tens of micrometers.

[0086] Furthermore, conventional pressure processing devices only apply the target processing force at the instant the movable table reaches the bottom dead center (see reference). Figure 8 In contrast, the pressure processing apparatus equipped with the mold structure of the present invention continuously applies a target processing force to the workpiece relative to the upper mold during a certain period before and after the movable table reaches the bottom dead center position, i.e., during the period when the upper mold remains at the target bottom dead center position (see reference). Figure 10 The pressure processing apparatus equipped with the mold structure of the present invention can maintain the bottom dead center time of the upper die for a longer period, thus allowing for a longer application time of the target processing force. Therefore, unlike servo presses which reduce processing speed, springback is significantly reduced, resulting in excellent productivity. Furthermore, in conventional pressure processing apparatuses, the bottom dead center time of the upper die is on the order of a few microseconds to tens of microseconds. In contrast, using the mold structure of the present invention allows for a longer bottom dead center time of the upper die.

[0087] In sequential press processing, the metal components slide and collide repeatedly at high speeds, which, compared to a single press, can easily cause a shift in the bottom dead center position of the movable table due to press vibration and the expansion of the heated housing. Therefore, the mold structure of the present invention, which reduces the impact of unstable positioning accuracy caused by the press body, is particularly well-suited for sequential press processing applications.

[0088] based on Figure 5 This invention describes an example of a processed article made by pressure processing a material using the pressure processing apparatus of the present invention. Figure 5 This is a three-dimensional view of connector terminals manufactured by continuously shearing, bending, and other processing of copper plates as the workpiece material. For example... Figure 5 As shown, the connector terminal 40 has multiple bends and punched portions. The length of the long side of the connector terminal 40 is 30mm, the thickness of the metal plate is 0.5mm, and the width of the terminal tip is 2.3mm.

[0089] In the pressure processing method and pressure processing apparatus of the present invention, as described above, since the time for applying the target processing force relative to the processed material can be increased, the springback can be significantly reduced, and such processed products can be processed with high precision and high productivity.

[0090] Industrial utilization potential

[0091] The mold structure of the present invention reduces the impact of unstable positioning accuracy caused by the press body, eliminates the need for adjustment of the pressure processing device by a skilled technician, exhibits excellent growth characteristics, and is easy to install and disassemble relative to the press body. Therefore, it can be used for processing various metal parts used in electronic equipment, automobiles, etc.

[0092] Explanation of symbols

[0093] 1, 1': Mold construction

[0094] 2: Fixed platform

[0095] 3: Lower mold

[0096] 3a, 3b: Metal plates

[0097] 4: Upper mold

[0098] 4a, 4b: Metal plates

[0099] 5: Movable platform

[0100] 6.6: Pressure Adjustment Device

[0101] 7: Pressure plate

[0102] 8: Second elastic body

[0103] 9: Suppression Component

[0104] 10: Stopper

[0105] 10a: Upper stop

[0106] 10b: Lower stop

[0107] 11: First elastic body

[0108] 12: Guide components

[0109] 12a: Guide rod

[0110] 12b, 12c Intercalation Components

[0111] 13: Restricting components

[0112] 14: Stamping Die

[0113] 15: concave part

[0114] 16: Shedding Prevention Section

[0115] 17: Piston rod

[0116] 18: Shell

[0117] 19: Fluid

[0118] 30: Processed material

[0119] 40: Connector terminal.

Claims

1. A mold structure for pressure processing of a workpiece material, disposed between a movable table and a fixed table of a press body, characterized in that, The aforementioned mold structure includes a lower mold fixed to the aforementioned fixed platform; an upper mold disposed above the lower mold; a first elastic body and a stop disposed between the upper mold and the lower mold; and a pressure adjustment device connected to the movable platform side of the aforementioned upper mold. The aforementioned pressure adjustment device includes a pressure plate that abuts against the aforementioned movable stage; and a second elastic body disposed between the aforementioned pressure plate and the aforementioned upper mold. During the non-pressurized state of the aforementioned pressure processing, the first elastic body causes the upper die and the lower die to separate. During pressurization, the stopper, while defining the bottom dead center position of the upper die, applies pressure from the movable table to the upper die via the pressure plate of the pressure adjustment device through the second elastic body, thereby clamping the processed material between the upper die and the lower die.

2. The mold structure according to claim 1, characterized in that, The upper end face of the second elastic body abuts against the lower surface of the pressure plate in a non-fixed manner.

3. The mold structure according to claim 1, characterized in that, The second elastic body mentioned above is a fluid spring.

4. The mold structure according to claim 3, characterized in that, The fluid spring described above has a housing, a fluid sealed inside the housing, and a piston rod that can extend and retract axially within the housing. The upper end face of the piston rod is in contact with the lower surface of the pressure plate in a non-fixed manner, and pressure is applied axially from the pressure plate relative to the piston rod in the housing.

5. The mold structure according to claim 1, characterized in that, The mold structure described above has components that suppress changes in the speed and acceleration of the upper mold.

6. A pressure processing apparatus, characterized in that, The device comprises the mold structure as described in claim 1; a fixed platform for fixing the lower mold of the mold structure; and a movable platform for abutting the pressure plate of the mold structure.

7. A pressure processing method, wherein the material to be processed is pressure processed using the mold structure described in claim 1, characterized in that, After the material to be processed is placed on the lower die, the lower die, which is in a state of separation from the first elastic body, is lowered by the pressure of the movable table through the pressure adjustment device and positioned at the target bottom dead center by the stop. With the upper mold positioned, the movable stage pushes the second elastic body of the pressure adjustment device to shrink while descending to the bottom dead center of the descending stage. During the period from when the movable stage changes to an upward stroke until the compression of the second elastic body is released, the material to be processed is clamped between the upper die and the lower die for a specified time for pressure processing by keeping the upper die at the target bottom dead center position.

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