Press device

Abstract

To provide a press device which can accurately crimp a workpiece in a lamination process.SOLUTION: A press device 11 presses a workpiece 21 and includes: a first die 12; a second die 13 which moves relative to the first die 12; a piston 31 which moves the second die 13 and is a cylindrical body; and a first additional piston 34 which cooperates with the piston 31 to move the second die 13 and is a cylindrical body or a columnar body. The piston 31 includes: one annular pressing surface 33C which contacts with the second die and presses the second die 13; a first center axis C1; and a first through hole 31A extending in a direction along the first center axis C1. The first additional piston 34 has: a second center axis C2 arranged coaxially with the first center axis C1; and a first additional pressing surface 36B configured to contact with the second die 13 and press the second die 13 and is disposed within the first through hole 31A.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a press apparatus. [Background technology]

[0002] The press device includes a laminator for manufacturing a multilayer electronic component. For example, the press device described in Patent Document 1 laminates a film-shaped resin material by pressing. The press device is also configured as a laminator for laminating ceramic green sheets in a manufacturing process of a multilayer capacitor. These press devices are equipped with a piston. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-12918 A Summary of the Invention [Problem to be solved by the invention]

[0004] If the thrust of the piston is concentrated in the center, there is a risk that the press table that comes into contact with the workpiece will bend. It is preferable that the press device be capable of pressing the workpieces with high precision in the lamination process. [Means for solving the problem]

[0005] (1) A press device that solves the above problem is a press device that presses a workpiece, and includes a first die, a second die that moves relative to the first die, and a piston that moves the second die, the piston having an annular pressing surface that presses the second die.

[0006] According to this configuration, it is possible to prevent the thrust of the piston from concentrating on the center of the second die, and therefore the press device can press the workpiece with high precision.

[0007] (2) In the press device of (1) above, the piston is a cylinder. With this configuration, it is possible to prevent the thrust of the piston from concentrating at the center of the second die. Furthermore, when the piston is a cylinder, the piston has an inner piston surface and an outer piston surface. Therefore, the piston can be guided by the inner piston surface and also by the outer piston surface. This improves the linearity of the piston. By improving the linearity of the piston, it is possible to improve the stacking accuracy of the workpieces.

[0008] (3) In the press device of (1) or (2) above, the piston has a first central axis and a first through hole extending in a direction along the first central axis, and further includes a first additional piston that cooperates with the piston to move the second die, the first additional piston being a cylinder or columnar body, having a second central axis coaxial with the first central axis, and being disposed within the first through hole.

[0009] According to this configuration, pressure can be suitably applied to the workpiece by the piston and the first additional piston.

[0010] (4) In the press device of (3) above, one of the piston and the first additional piston is fixed to the second die, and the other of the piston and the first additional piston is movable relative to the second die.

[0011] According to this configuration, when the piston and the first additional piston are operated so as to move the second mold toward the first mold, it is possible to suppress the generation of air bubbles in the cylinder that supports the piston.

[0012] (5) The press device according to (4) above, further comprising a hydraulic device that moves the piston and the first additional piston independently of each other.

[0013] According to this configuration, the piston and the first additional piston can be moved independently of each other by the hydraulic device.

[0014] (6) The press device of (5) above further includes a cylinder supporting the piston and a first additional cylinder supporting the first additional piston, and the hydraulic device has a first hydraulic system that moves the piston within the cylinder so that the second die moves in a first direction approaching the first die, and a second hydraulic system that moves the first additional piston within the first additional cylinder so that the second die moves in the first direction.

[0015] According to this configuration, the piston and the first additional piston can be operated by different hydraulic systems.

[0016] (7) The press device of (6) above further includes a biasing device that biases the piston and the first additional piston, the biasing device having a first biasing portion that biases the piston in the cylinder so that the second die moves in a second direction away from the first die, and a second biasing portion that biases the first additional piston in the first additional cylinder so that the second die moves in the second direction.

[0017] According to this configuration, the piston and the first additional piston can be operated by the biasing portion so as to move the second mold in the second direction.

[0018] (8) In any of the press devices described above in (6) or (7), a control unit is further provided that controls the hydraulic device, and the control unit controls the hydraulic device so that, when a workpiece is pressurized, a pressurization timing of one of the piston and the first additional piston is different from a pressurization timing of the other of the piston and the first additional piston.

[0019] According to this configuration, it is possible to apply pressure to the workpiece pressed by the first die and the second die in different ways.

[0020] (9) The press device described in (6) above further includes a second additional piston that cooperates with the piston and the first additional piston to move the second die, the second additional piston being cylindrical and having a third central axis coaxial with the first central axis and the second central axis, and a second through hole extending in a direction along the third central axis, and the piston and the first additional piston are disposed within the second through hole.

[0021] According to this configuration, pressure can be suitably applied to the workpiece by the piston, the first additional piston, and the second additional piston.

[0022] (10) In the press device described in (9) above, one of the piston, the first additional piston, and the second additional piston is fixed to the second mold, and the remaining two of the piston, the first additional piston, and the second additional piston are movable relative to the second mold.

[0023] According to this configuration, when the piston, the first additional piston, and the second additional piston are operated so as to move the second mold toward the first mold, it is possible to suppress the generation of air bubbles in the cylinder supporting the piston.

[0024] (11) In the press apparatus described above in (10), the hydraulic device is configured to move the piston, the first additional piston, and the second additional piston independently of one another, and further includes a control unit configured to control the hydraulic device, and the control unit is configured to control the hydraulic device such that, when a workpiece is pressurized, a pressurization timing of one of the piston, the first additional piston, and the second additional piston is different from a pressurization timing of the remaining two of the piston, the first additional piston, and the second additional piston.

[0025] According to this configuration, it is possible to apply pressure to the workpiece being pressed by the first die and the second die in different ways. Effect of the Invention

[0026] The press device of the present disclosure can press the workpiece with high precision. [Brief description of the drawings]

[0027] [Figure 1] FIG. 2 is a perspective view showing a partial cross section of the press device of the first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view of the press device of FIG. [Diagram 3] FIG. 3 is a plan view of a second die of the press apparatus of FIG. 2. [Figure 4] FIG. 11 is a cross-sectional view of a press device according to a second embodiment. [Diagram 5] FIG. 5 is a plan view of a second die of the press apparatus of FIG. 4. [Figure 6] FIG. 11 is a cross-sectional view of a press device according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] (First embodiment) The press device 11 will be described with reference to FIGS.

[0029] <Press equipment> The press device 11 is a device for pressing the work 21. The press device 11 presses the work 21 to bond the work 21. The press device 11 forms a laminate of the work 21 by repeatedly bonding the work 21 every time the work 21 is transported into the press device 11. The press device 11 is used to manufacture various types of multilayer electronic components. For example, the press device 11 is used in a lamination device section of an MLCC (Multi-Layer Ceramic Capacitor) lamination machine, a lamination device section of an LTCC (Low Temperature Co-fired Ceramics) lamination machine, a lamination device section of a lithium ion lamination machine, a lamination device section of a lamination machine for manufacturing a multilayer inductor, or a lamination device section of a lamination machine for manufacturing a multilayer resistor.

[0030] As shown in FIGS. 1 and 2, the press device 11 includes a first die 12, a second die 13 that moves relative to the first die 12, and a piston 31 that moves the second die 13.

[0031] The press device 11 further includes a frame 14. The frame 14 is made of metal. The frame 14 has a first frame portion 14A and a second frame portion 14B located below the first frame portion 14A.

[0032] The first die 12 is fixed to a frame 14. The frame 14 fixes the first die 12, the cylinder 41, and the first additional cylinder 42 so that the positional relationship between the first die 12, the cylinder 41, and the first additional cylinder 42 does not shift due to vibration. The first die 12 is fixed to the first frame portion 14A or the second frame portion 14B. In one example, the first die 12 is fixed to the first frame portion 14A.

[0033] The first die 12 is configured in a rectangular parallelepiped shape. The material of the first die 12 is metal. When the second die 13 moves toward the first die 12, the first die 12 receives a force applied thereto.

[0034] The second die 13 is configured as a rectangular parallelepiped. The material of the second die 13 is metal. When the second die 13 is pushed by the piston 31, the second die 13 moves in a first direction Z1 in which the second die 13 approaches the first die 12. When the piston 31 moves in the second direction Z2 in which the second die 13 moves away from the first die 12, the second die 13 moves in the second direction Z2.

[0035] The second die 13 has a first surface 13A and a second surface 13B opposite to the first surface 13A in the movement direction of the second die 13. The first surface 13A is a surface on which the workpiece 21 is provided. The second surface 13B is a surface with which the piston 31 and the first additional piston 34 come into contact.

[0036] <Work> The workpiece 21 is sandwiched between the first die 12 and the second die 13 and pressed by pressure. The workpiece 21 is a rectangular sheet. In one example, the workpiece 21 is a ceramic green sheet. The press device 11 stacks the multiple workpieces 21 one by one in order and presses them to form a laminate.

[0037] There is no particular limitation on the type and material of the workpiece 21. The workpiece 21 may be made of steel such as ordinary steel, special steel such as alloy steel and tool steel, non-ferrous metal such as copper and aluminum, or CFRP (Carbon Fiber Reinforced Plastics).

[0038] <Piston> The piston 31 is a cylindrical body. The cylindrical body includes a cylindrical body. In one example, the piston 31 is a cylindrical body. The piston 31 is composed of one or two cylindrical bodies. The piston 31 is made of a metal. The piston 31 has a first central axis C1 and a first through hole 31A extending in a direction along the first central axis C1.

[0039] The piston 31 is configured to be operated by hydraulic pressure. The piston 31 may also be configured to be operated by an electric actuator.

[0040] The piston 31 includes a main body 32 and a first cylindrical piston rod 33. The main body 32 is cylindrical. The main body 32 has a piston inner peripheral surface 32A and a piston outer peripheral surface 32B. The piston inner peripheral surface 32A corresponds to the first through hole 31A.

[0041] The first cylindrical piston rod 33 has a first cylindrical piston rod inner peripheral surface 33A and a first cylindrical piston rod outer peripheral surface 33B. The first cylindrical piston rod inner peripheral surface 33A corresponds to the first through hole 31A. The first cylindrical piston rod 33 is connected to an end surface of the main body portion 32. The central axis of the first cylindrical piston rod 33 and the central axis of the main body portion 32 coincide with each other. In one example, the first cylindrical piston rod 33 and the main body portion 32 are integrally formed. The main body portion 32 is configured to move the second die 13 relative to the first die 12 via the first cylindrical piston rod 33.

[0042] 2 and 3, the piston 31 has an annular pressing surface 33C that presses the second die 13. The pressing surface 33C is provided on the first cylindrical piston rod 33. The pressing surface 33C contacts the second die 13. The pressing surface 33C is provided on the end of the first cylindrical piston rod 33 opposite to the main body portion 32.

[0043] As shown in Fig. 1 and Fig. 2, the press device 11 further includes a first additional piston 34. The first additional piston 34 is a cylindrical body or a columnar body. The columnar body includes a circular columnar body or a rectangular columnar body. In one example, the first additional piston 34 is a circular columnar body.

[0044] The first additional piston 34 is made of a metal material. The first additional piston 34 has a second central axis C2 coaxial with the first central axis C1. The first additional piston 34 is disposed in the first through hole 31A of the piston 31.

[0045] The first additional piston 34 cooperates with the piston 31 to move the second die 13. The first additional piston 34 is configured to be operated by hydraulic pressure. The first additional piston 34 may be configured to be operated by an electric actuator.

[0046] The first additional piston 34 includes a first additional piston body portion 35 and a piston rod 36. The first additional piston body portion 35 has a first additional piston outer peripheral surface 35A. The piston rod 36 has a piston rod outer peripheral surface 36A. The piston rod 36 is connected to an end surface of the first additional piston body portion 35. The central axis of the piston rod 36 and the central axis of the first additional piston body portion 35 coincide with each other. In one example, the piston rod 36 and the first additional piston body portion 35 are integrally formed. The first additional piston 34 is configured to push the second mold 13 via the piston rod 36.

[0047] 2 and 3, the first additional piston 34 has a first additional pressing surface 36B that presses the second die 13. The first additional pressing surface 36B is provided on the piston rod 36. The first additional pressing surface 36B contacts the second die 13. The first additional pressing surface 36B is provided on the end of the piston rod 36 opposite to the first additional piston main body portion 35.

[0048] The first additional pressing surface 36B contacts approximately the center of the second surface 13B of the second die 13. The above-mentioned pressing surface 33C contacts the second surface 13B on the outer side of the portion with which the first additional pressing surface 36B contacts.

[0049] One of the piston 31 and the first additional piston 34 is fixed to the second die 13. Specifically, one of the pressing surface 33C of the first cylindrical piston rod 33 and the first additional pressing surface 36B of the piston rod 36 is fixed to the second die 13. In this embodiment, the first additional piston 34 is fixed to the second die 13.

[0050] The other of the piston 31 and the first additional piston 34 is movable relative to the second die 13. In other words, the other of the piston 31 and the first additional piston 34 is not fixed to the second die 13. Specifically, the other of the pressing surface 33C of the first cylindrical piston rod 33 and the first additional pressing surface 36B of the piston rod 36 is movable relative to the second die 13. In this embodiment, the piston 31 is movable relative to the second die 13.

[0051] <Cylinder> As shown in FIGS. 1 and 2, the press device 11 further includes a cylinder 41 that supports the piston 31, and a first additional cylinder that supports the first additional piston .

[0052] The cylinder 41 includes a hollow cylindrical body. The material of the cylinder 41 is metal. The cylinder 41 has an internal space S. A part of the first cylindrical piston rod 33 and the main body portion 32 are disposed in the internal space S of the cylinder 41.

[0053] The cylinder 41 has a first cylinder inner circumferential surface 41 A and a second cylinder inner circumferential surface 41 B. The first cylinder inner circumferential surface 41A is provided on the inside of the second cylinder inner circumferential surface 41B.

[0054] The cylinder 41 has a cylinder through hole 41C. The cylinder through hole 41C is annular. The first cylindrical piston rod 33 passes through the cylinder through hole 41C and comes into contact with the second die 13.

[0055] The cylinder 41 has a first pressure chamber 43. The first pressure chamber 43 is a part of the internal space S. Oil is supplied to or discharged from a first hydraulic pump 54 via a first port 55 to the first pressure chamber 43. When oil is supplied to the first pressure chamber 43 and oil is discharged from the second pressure chamber 44, the piston 31 operates to move the second die 13 in the first direction Z1.

[0056] The cylinder 41 has a second pressure chamber 44. The second pressure chamber 44 is a part of the internal space S. Oil is supplied to or discharged from the first hydraulic pump 54 via a second port 56 to the second pressure chamber 44. When oil is supplied to the second pressure chamber 44 and oil is discharged from the first pressure chamber 43, the piston 31 operates to move the second die 13 in the second direction Z2.

[0057] The first additional cylinder 42 includes a hollow cylindrical body. The material of the first additional cylinder 42 is metal. The first additional cylinder 42 has a first internal space S1. A part of the piston rod 36 and the first additional piston main body portion 35 are disposed in the first internal space S1 of the first additional cylinder 42. The first additional cylinder 42 has a first additional cylinder inner circumferential surface 42B.

[0058] The first additional cylinder 42 has a first additional cylinder through hole 42C. The first additional cylinder through hole 42C is provided along the first additional cylinder 42 at an end of the first additional cylinder 42 on the second die 13 side. The piston rod 36 passes through the first additional cylinder through hole 42C and comes into contact with the second die 13.

[0059] The first additional cylinder 42 has a third pressure chamber 45. The third pressure chamber 45 is a part of the first internal space S1. Oil is supplied to or discharged from the second hydraulic pump 58 via a third port 59 to the third pressure chamber 45. When oil is supplied to the third pressure chamber 45 and oil is discharged from the fourth pressure chamber 46, the first additional piston 34 operates to move the second die 13 in the first direction Z1.

[0060] The first additional cylinder 42 has a fourth pressure chamber 46. The fourth pressure chamber 46 is a part of the first internal space S1. Oil is supplied to or discharged from the second hydraulic pump 58 via a fourth port 60 to the fourth pressure chamber 46. When oil is supplied to the fourth pressure chamber 46 and oil is discharged from the third pressure chamber 45, the first additional piston 34 operates to move the second die 13 in the second direction Z2.

[0061] <Hydraulic system> As shown in FIG. 2, the press device 11 further includes a hydraulic device 51 that moves the piston 31 and the first additional piston 34 independently of each other.

[0062] The hydraulic device 51 has a first hydraulic system 52 and a second hydraulic system 53. The first hydraulic system 52 moves the piston 31 in the cylinder 41 so that the second die 13 moves in the first direction Z1 or the second direction Z2. The first hydraulic system 52 includes a first hydraulic pump 54, a first port 55, a second port 56, and a first switching valve 57. The first hydraulic pump 54 is connected to the first pressure chamber 43 of the cylinder 41 via the first switching valve 57 and the first port 55. The first hydraulic pump 54 is also connected to the second pressure chamber 44 of the cylinder 41 via the first switching valve 57 and the second port 56.

[0063] The second hydraulic system 53 moves the first additional piston 34 in the first additional cylinder 42 so that the second die 13 moves in the first direction Z1 or the second direction Z2. The second hydraulic system 53 includes a second hydraulic pump 58, a third port 59, a fourth port 60, and a second switching valve 61. The second hydraulic pump 58 is connected to the third pressure chamber 45 of the first additional cylinder 42 via the second switching valve 61 and the third port 59. The second hydraulic pump 58 is connected to the fourth pressure chamber 46 of the first additional cylinder 42 via the second switching valve 61 and the fourth port 60.

[0064] <Seal> The press device 11 has one or more first seals 71A. The first seal 71A is a seal for preventing oil in the first pressure chamber 43 of the cylinder 41 from entering the second pressure chamber 44 of the cylinder 41. The first seal 71A is ring-shaped. The material of the first seal 71A is synthetic resin or rubber. The first seal 71A is arranged in a first seal arrangement portion 71B. The first seal arrangement portion 71B is provided on the piston outer circumferential surface 32B.

[0065] The press device 11 has one or more second seals 72A. The second seal 72A, together with the first seal 71A, is a seal for preventing oil in the first pressure chamber 43 from entering the second pressure chamber 44. The second seal 72A is ring-shaped. The second seal 72A is made of synthetic resin or rubber. The second seal 72A is arranged in a second seal arrangement portion 72B. The second seal arrangement portion 72B is provided on the first cylinder inner circumferential surface 41A.

[0066] The press device 11 has a third seal 73A. The third seal 73A is a seal for preventing oil in the second pressure chamber 44 from leaking to the outside through the cylinder through hole 41C when the first cylindrical piston rod 33 moves. The third seal 73A is ring-shaped. The material of the third seal 73A is synthetic resin or rubber. The third seal 73A is arranged in a third seal arrangement portion 73B. The third seal arrangement portion 73B is provided on the outer circumferential surface 33B of the first cylindrical piston rod.

[0067] The press device 11 has a fourth seal 74A. The fourth seal 74A, together with the third seal 73A, is a seal for preventing oil in the second pressure chamber 44 from leaking out of the cylinder through hole 41C when the first cylindrical piston rod 33 moves. The fourth seal 74A is ring-shaped. The material of the fourth seal 74A is synthetic resin or rubber. The fourth seal 74A is disposed in a fourth seal arrangement portion 74B. The fourth seal arrangement portion 74B is provided in the cylinder through hole 41C.

[0068] The press device 11 has one or more fifth seals 75A. The fifth seal 75A is a seal for preventing oil in the third pressure chamber 45 of the first additional cylinder 42 from entering the fourth pressure chamber 46 of the first additional cylinder 42. The fifth seal 75A is ring-shaped. The material of the fifth seal 75A is synthetic resin or rubber. The fifth seal 75A is disposed in a fifth seal arrangement portion 75B. The fifth seal arrangement portion 75B is provided on the first additional piston outer peripheral surface 35A.

[0069] The press device 11 has a sixth seal 76A. The sixth seal 76A is a seal for preventing oil in the fourth pressure chamber 46 from leaking to the outside through the first additional cylinder through-hole 42C when the piston rod 36 moves. The sixth seal 76A is ring-shaped. The material of the sixth seal 76A is synthetic resin or rubber. The sixth seal 76A is arranged in a sixth seal arrangement portion 76B. The sixth seal arrangement portion 76B is provided on the piston rod outer circumferential surface 36A.

[0070] <Wearing> The press device 11 has one or more first wear rings 81A. The first wear ring 81A is a bearing material for guiding the piston 31 to move along the cylinder 41 when the piston 31 moves. The first wear ring 81A is cylindrical. The material of the first wear ring 81A is synthetic resin.

[0071] The first wear ring 81A is disposed in the first wear ring arrangement portion 81B. The first wear ring arrangement portion 81B is provided on the piston outer circumferential surface 32B. In one example, the first wear ring arrangement portion 81B is provided in a portion of the piston outer circumferential surface 32B that is farther from the second die 13 than the first seal arrangement portion 71B. The arrangement and number of the first wear rings 81A are not limited to this example.

[0072] The press device 11 has one or more second wear rings 82A. The second wear ring 82A, together with the first wear ring 81A, is a bearing material for guiding the piston 31 to move along the cylinder 41 when the piston 31 moves. The second wear ring 82A is ring-shaped. The material of the second wear ring 82A is synthetic resin.

[0073] The second wear ring 82A is disposed in the second wear ring disposing portion 82B. The second wear ring disposing portion 82B is provided on the first cylinder inner circumferential surface 41A. In one example, the second wear ring disposing portion 82B is provided in a portion of the first cylinder inner circumferential surface 41A that is farther from the second die 13 than the second seal disposing portion 72B. The disposition and number of the second wear ring 82A are not limited to this example.

[0074] The press device 11 has one or more third wear rings 83A. The third wear ring 83A is a bearing material for guiding the first additional piston 34 to move along the first additional cylinder 42 when the first additional piston 34 moves. The third wear ring 83A is ring-shaped. The material of the third wear ring 83A is synthetic resin.

[0075] The third wear ring 83A is disposed in the third wear ring disposing portion 83B. The third wear ring disposing portion 83B is provided on the first additional piston outer circumferential surface 35A. In one example, the third wear ring disposing portion 83B is provided in a portion of the first additional piston outer circumferential surface 35A that is farther from the second die 13 than the fifth seal disposing portion 75B. The disposition and number of the third wear ring 83A are not limited to this example.

[0076] <Control Unit> The press apparatus 11 further includes a control unit 91. The control unit 91 includes an arithmetic processing device that executes a predetermined control program. The arithmetic processing device included in the control unit 91 includes, for example, a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). The arithmetic processing devices included in the control unit 91 may be provided in multiple locations separated from each other. The control unit 91 may include one or multiple microcomputers.

[0077] The press apparatus 11 further includes a storage unit 92. The storage unit 92 is communicably connected to the control unit 91, for example, via wire or wirelessly. The storage unit 92 stores, for example, a control program and information used in the control process.

[0078] The storage unit 92 includes, for example, a non-volatile memory and a volatile memory. The non-volatile memory includes, for example, at least one of a Read-Only Memory (ROM), an Erasable Programmable Read Only Memory (EPROM), an Electrically Erasable Programmable Read-Only Memory (EEPROM), and a flash memory. The volatile memory includes, for example, a Random Access Memory (RAM).

[0079] The control unit 91 controls the hydraulic device 51. When the second die 13 is moved in the first direction Z1 or the second direction Z2, the control unit 91 controls the hydraulic device 51 so that the piston 31 operates in the first hydraulic system 52.

[0080] When the control unit 91 moves the second die 13 in the first direction Z1 or the second direction Z2, the control unit 91 controls the hydraulic device 51 so that the first additional piston 34 operates in the second hydraulic system 53.

[0081] When the second mold 13 is moved in the first direction Z1, the control unit 91 controls the hydraulic device 51 so that one of the piston 31 and the first additional piston 34 moves faster than the other of the piston 31 and the first additional piston 34. In one example, when the second mold 13 is moved in the first direction Z1, the control unit 91 controls the hydraulic device 51 so that the first additional piston 34 fixed to the second mold 13 moves faster than the piston 31. This makes it possible to suppress frequent occurrence of a bubble generation state, which will be described later.

[0082] When the second mold 13 is moved in the second direction Z2, the control unit 91 controls the hydraulic device 51 so that the other of the piston 31 and the first additional piston 34 moves faster than one of the piston 31 and the first additional piston 34. In one example, when the second mold 13 is moved in the second direction Z2, the control unit 91 controls the hydraulic device 51 so that the piston 31 that is not fixed to the second mold 13 moves faster than the first additional piston 34. This makes it possible to suppress frequent occurrence of a bubble generation state, which will be described later.

[0083] Furthermore, the control unit 91 controls the hydraulic device 51 so that, when the workpiece 21 is pressurized, the pressurization timing of one of the piston 31 and the first additional piston 34 differs from the pressurization timing of the other of the piston 31 and the first additional piston 34. In this embodiment, the pressurization timing based on the first additional piston 34 is earlier in time than the pressurization timing based on the piston 31. This makes it possible to pressurize the center of the workpiece 21 before the periphery of the center.

[0084] In another example, the control unit 91 controls the first additional piston 34 and the piston 31 so that the pressurization timing based on the first additional piston 34 is later in time than the pressurization timing based on the piston 31 (hereinafter, specific timing control). This allows the periphery of the central part of the workpiece 21 to be pressurized before the central part. Such specific timing control makes it possible to suppress lateral displacement of the workpieces 21 when stacking the workpieces 21. When this control is executed, it is preferable that the piston 31 is fixed to the second die 13 and the first additional piston 34 is not fixed to the second die 13, as described in a modified example described later.

[0085] <Operation principle> The principle of operation of the press device 11 when pressing the workpiece 21 will now be described.

[0086] In the first hydraulic system 52, oil is continuously supplied to the first pressure chamber 43, whereby the piston 31 moves in the first direction Z1 at a first speed V1.

[0087] In the second hydraulic system 53, the first additional piston 34 moves in the first direction Z1 at a second speed V2 by continuously supplying oil to the third pressure chamber 45. The second speed V2 is slightly faster than the first speed V1. That is, the piston 31 moves slightly slower than the first additional piston 34.

[0088] A problem occurs when the speed of the piston 31 becomes faster than the speed of the first additional piston 34. When the speed of the piston 31 becomes faster than the speed of the first additional piston 34, the speed of the second die 13 moved by the thrust of the piston 31 becomes faster than the speed of the first additional piston 34 itself based on the supply of oil. However, since the first additional piston 34 is fixed to the second die 13, the first additional piston 34 actually moves at the same speed as the second die 13.

[0089] At this time, a mismatch occurs between the speed of the first additional piston 34 based on the supply of oil and the actual speed of the first additional piston 34. Specifically, the supply of oil is not keeping up with the speed of the first additional piston 34. As a result, air bubbles are generated in the first additional cylinder 42 (hereinafter, this phenomenon is referred to as the "air bubble generation state"). In order to suppress such a phenomenon, the speed of the first additional piston 34 fixed to the second mold 13 (i.e., the second speed V2) is set to a value greater than the speed of the piston 31 not fixed to the second mold 13 (i.e., the first speed V1).

[0090] Instead of setting the second speed V2 to be greater than the first speed V1, the following measure can be taken. The timing at which the piston 31 starts moving is set to be later than the timing at which the first additional piston 34 starts moving. This also makes it possible for the piston 31 to move later than the first additional piston 34.

[0091] When the workpiece 21 contacts the first die 12, immediately after pressure is applied to the center of the second die 13 by the first additional piston 34 via the first additional pressing surface 36B, pressure is applied to the periphery of the center of the second die 13 by the piston 31 via the pressing surface 33C. Since pressure is applied to both the center and its periphery on the second surface 13B of the second die 13 by the piston 31 and the first additional piston 34, the deflection of the second die 13 that occurs when the second die 13 contacts the first die 12 is eliminated. Therefore, uniform pressure is easily applied to the entire surface of the workpiece 21. Therefore, the workpiece 21 can be crimped with high precision.

[0092] (Effects of the first embodiment) The effects of the first embodiment will be described. (1) The press device 11 presses the workpiece 21 and includes a first die 12, a second die 13 that moves relative to the first die 12, and a piston 31 that moves the second die 13. The piston 31 has an annular pressing surface 33C that presses the second die 13.

[0093] When the center of the second die 13 is pressed by one piston 31 as in the conventional technology, the second die 13 is slightly curved by the pressure applied to the center of the second die 13. This causes a difference in pressure applied to the work 21 between the center of the work 21 and the periphery of the center. If a pressure gradient occurs from the center to the periphery, there is a risk of quality variation occurring between the center of the work 21 and the periphery of the work 21. In addition, when the center of the second die 13 is pressed by the piston 31, if the pressing direction of the piston 31 is inclined relative to the second die 13, there is a risk of lateral displacement of the work 21 during stacking of the work 21 due to part of the pressing force acting horizontally. In the manufacture of a stack of the work 21, the lateral displacement of the work 21 greatly affects the yield. Such a problem becomes apparent when the second die 13 is enlarged.

[0094] In this regard, the above-described configuration can prevent the thrust of the piston 31 from concentrating on the center of the second die 13. Therefore, the press device 11 can press the workpiece 21 with high accuracy.

[0095] (2) The piston 31 is a cylindrical body. With this configuration, it is possible to prevent the thrust of the piston 31 from concentrating on the center of the second die 13. Furthermore, when the piston 31 is a cylindrical body, the piston 31 has a piston inner peripheral surface 32A and a piston outer peripheral surface 32B, and therefore the piston 31 can be guided by the piston inner peripheral surface 32A and also by the piston outer peripheral surface 32B. This improves the linearity of the piston 31. The improved linearity of the piston 31 improves the stacking accuracy of the workpiece 21.

[0096] (3) The piston 31 has a first central axis C1 and a first through hole 31A extending in a direction along the first central axis C1, and further includes a first additional piston 34 that cooperates with the piston 31 to move the second die 13, the first additional piston 34 being a cylindrical or columnar body, having a second central axis C2 coaxial with the first central axis C1, and being disposed within the first through hole 31A.

[0097] According to this configuration, pressure can be applied to the workpiece 21 suitably by the piston 31 and the first additional piston .

[0098] (4) One of the piston 31 and the first additional piston 34 is fixed to the second mold 13 , and the other of the piston 31 and the first additional piston 34 is movable relative to the second mold 13 .

[0099] When the second mold 13 is moved by a plurality of pistons, it is possible to fix the plurality of pistons to the second mold 13. In this case, it is necessary to move each of the plurality of pistons with high precision by a hydraulic pump. If the timing of the movement of the plurality of pistons is out of sync, or if any one of the pistons moves faster than the other pistons, an event caused by the asynchronous movement of the plurality of pistons (hereinafter, asynchronous event) generates air bubbles in the cylinder (hereinafter, air bubble generation state). When air bubbles are generated in the cylinder, it becomes difficult to apply hydraulic pressure to the pistons, and the movement of the second mold 13 is hindered. An asynchronous event occurs when the pistons are not sufficiently synchronized when the plurality of pistons are operated in a case where the plurality of pistons are fixed to one mold (hereinafter, multiple fixed state). When the plurality of pistons are fixed to one mold (hereinafter, multiple fixed state), the plurality of pistons are constrained to each other via the one mold. For this reason, the pistons move the same distance as the mold moves. In other words, the movement amount of the pistons is equal at each time from the start of the movement.

[0100] On the other hand, even if hydraulic control is performed to synchronize the pistons, unless the control is highly accurate, there will be variation in the amount of oil supplied to each of the cylinders or the amount of oil discharged from each of the cylinders. This causes a mismatch between the amount of movement of one or more of the pistons and the amount of oil supplied to the cylinder that supports the piston. When such a mismatch occurs, air bubbles are generated in the cylinder. When air bubbles are generated in the cylinder, sufficient hydraulic pressure is not applied to the piston as described above.

[0101] According to the above configuration, the piston 31 and the first additional piston 34 move independently of each other, so that when the piston 31 and the first additional piston 34 are operated so as to move the second mold 13 toward the first mold 12, the generation of air bubbles in the cylinder 41 supporting the piston 31 can be suppressed.

[0102] (5) The hydraulic device 51 is further provided to move the piston 31 and the first additional piston 34 independently of each other.

[0103] According to this configuration, the piston 31 and the first additional piston 34 can be moved by the hydraulic device 51 independently of each other.

[0104] (6) The hydraulic device 51 further includes a cylinder 41 supporting the piston 31 and a first additional cylinder 42 supporting the first additional piston 34. The hydraulic device 51 has a first hydraulic system 52 that moves the piston 31 within the cylinder 41 so that the second die 13 moves in a first direction Z1 toward the first die 12, and a second hydraulic system 53 that moves the first additional piston 34 within the first additional cylinder 42 so that the second die 13 moves in the first direction Z1.

[0105] According to this configuration, the piston 31 and the first additional piston 34 can be operated by different hydraulic systems.

[0106] (7) The hydraulic device 51 is further provided with a control unit 91 that controls the hydraulic device 51. The control unit 91 controls the hydraulic device 51 so that the pressurizing timing of one of the piston 31 and the first additional piston 34 differs from the pressurizing timing of the other of the piston 31 and the first additional piston 34 when the workpiece 21 is pressurized.

[0107] According to this configuration, it is possible to apply pressure to the workpiece 21 pressed by the first die 12 and the second die 13 in different ways. For example, by controlling the hydraulic device 51, it is possible to apply pressure to the workpiece 21 in such a manner that pressure is applied to the central portion of the workpiece 21, and then pressure is applied to the peripheral portions of the workpiece 21. It is also possible to apply pressure to the workpiece 21 in such a manner that pressure is applied to the peripheral portions of the workpiece 21, and then pressure is applied to the central portion of the workpiece 21.

[0108] Second embodiment A press device 11 according to a second embodiment will be described with reference to Fig. 4 and Fig. 5. In the second embodiment, differences from the first embodiment will be described. Members similar to those in the first embodiment will be given the same names and descriptions thereof will be omitted.

[0109] <Second additional piston> The press device 11 of the second embodiment further includes a second additional piston 37 in addition to the piston 31 and the first additional piston 34. The second additional piston 37 is a cylindrical body. In one example, the second additional piston 37 is a cylindrical body. The material of the second additional piston 37 is metal.

[0110] The second additional piston 37 has a third central axis C3 and a second through hole 37A extending in a direction along the third central axis C3. The third central axis C3 is coaxial with the first central axis C1 and the second central axis C2. The piston 31 and the first additional piston 34 are disposed in the second through hole 37A of the second additional piston 37.

[0111] The second additional piston 37 cooperates with the piston 31 and the first additional piston 34 to move the second die 13. The second additional piston 37 is configured to be operated by hydraulic pressure. The second additional piston 37 may be configured to be operated by an electric actuator.

[0112] The second additional piston 37 includes a second additional piston body 38 and a second cylindrical piston rod 39. The second additional piston body 38 has a second additional piston inner circumferential surface 38A and a second additional piston outer circumferential surface 38B. The second additional piston inner circumferential surface 38A corresponds to the second through hole 37A.

[0113] The second cylindrical piston rod 39 has a second cylindrical piston rod inner peripheral surface 39A and a second cylindrical piston rod outer peripheral surface 39B. The second cylindrical piston rod inner peripheral surface 39A corresponds to the second through hole 37A. The second additional piston body 38 is configured to move the second die 13 relative to the first die 12 via the second cylindrical piston rod 39.

[0114] As shown in Figures 4 and 5, the second additional piston 37 has an annular second additional pressing surface 39C that presses the second die 13. The second additional pressing surface 39C is provided on the second cylindrical piston rod 39. The second additional pressing surface 39C contacts the second die 13. The second additional pressing surface 39C is provided on the end of the second cylindrical piston rod 39 opposite to the second additional piston main body portion 38. The second additional pressing surface 39C contacts the second surface 13B of the second die 13 outside the pressing surface 33C.

[0115] One of the piston 31, the first additional piston 34, and the second additional piston 37 is fixed to the second die 13. Specifically, one of the pressing surface 33C of the first cylindrical piston rod 33, the first additional pressing surface 36B of the piston rod 36, and the second additional pressing surface 39C of the second cylindrical piston rod 39 is fixed to the second die 13. In this embodiment, the first additional piston 34 is fixed to the second die 13.

[0116] The remaining two of the piston 31, the first additional piston 34, and the second additional piston 37 are movable relative to the second die 13. In other words, the remaining two of the piston 31, the first additional piston 34, and the second additional piston 37 are not fixed to the second die 13. Specifically, the remaining two of the pressing surface 33C of the first cylindrical piston rod 33, the first additional pressing surface 36B of the piston rod 36, and the second additional pressing surface 39C of the second cylindrical piston rod 39 are movable relative to the second die 13. In this embodiment, the piston 31 and the second additional piston 37 are movable relative to the second die 13.

[0117] <Second additional cylinder> The press device 11 of the second embodiment further includes a second additional cylinder 47 in addition to the cylinder 41 and the first additional cylinder 42. The second additional cylinder 47 includes a hollow cylindrical body. The material of the second additional cylinder 47 is metal. The second additional cylinder 47 has a second internal space S2. A part of the second cylindrical piston rod 39 and the second additional piston main body portion 38 are disposed in the second internal space S2 of the second additional cylinder 47.

[0118] The second additional cylinder 47 has a first inner circumferential surface 47A and a second inner circumferential surface 47B. The first inner circumferential surface 47A is an inner circumferential surface on the cylinder 41 side of the second additional cylinder 47. The second inner circumferential surface 47B is disposed outside the first inner circumferential surface 47A in a radial direction perpendicular to the third central axis C3.

[0119] The second additional cylinder 47 has a second additional cylinder through hole 47C. The second additional cylinder through hole 47C is annular. The second cylindrical piston rod 39 passes through the second additional cylinder through hole 47C and comes into contact with the second die 13.

[0120] The second additional cylinder 47 has a fifth pressure chamber 48. The fifth pressure chamber 48 is a part of the second internal space S2. Oil is supplied to and discharged from the third hydraulic pump 63 via a fifth port 64 to the fifth pressure chamber 48. When oil is supplied to the fifth pressure chamber 48 and oil is discharged from the sixth pressure chamber 49, the second additional piston 37 operates to move the second die 13 in the first direction Z1.

[0121] The second additional cylinder 47 has a sixth pressure chamber 49. The sixth pressure chamber 49 is a part of the second internal space S2. Oil is supplied to and discharged from the third hydraulic pump 63 via a sixth port 65 to the sixth pressure chamber 49. When oil is supplied to the sixth pressure chamber 49 and oil is discharged from the fifth pressure chamber 48, the second additional piston 37 operates to move the second die 13 in the second direction Z2.

[0122] <Hydraulic system> The hydraulic device 51 of the second embodiment is configured to move the piston 31, the first additional piston 34, and the second additional piston 37 independently of each other.

[0123] The hydraulic device 51 has a third hydraulic system 62 in addition to the first hydraulic system 52 and the second hydraulic system 53. The third hydraulic system 62 moves the second additional piston 37 in the second additional cylinder 47 so that the second die 13 moves in the first direction Z1 or the second direction Z2. The third hydraulic system 62 includes a third hydraulic pump 63, a fifth port 64, a sixth port 65, and a third switching valve 66. The third hydraulic pump 63 is connected to the fifth pressure chamber 48 of the second additional cylinder 47 via the third switching valve 66 and the fifth port 64. The third hydraulic pump 63 is connected to the sixth pressure chamber 49 of the second additional cylinder 47 via the third switching valve 66 and the sixth port 65.

[0124] <Seal> The press device 11 has one or more seventh seals 77A. The seventh seal 77A is a seal for preventing oil in the fifth pressure chamber 48 from entering the sixth pressure chamber 49. The seventh seal 77A is ring-shaped. The seventh seal 77A is made of synthetic resin or rubber. The seventh seal 77A is arranged in a seventh seal arrangement portion 77B. The seventh seal arrangement portion 77B is provided on the second additional piston outer circumferential surface 38B.

[0125] The press device 11 has one or more eighth seals 78A. The eighth seal 78A, together with the seventh seal 77A, is a seal for preventing oil in the fifth pressure chamber 48 from entering the sixth pressure chamber 49. The eighth seal 78A is ring-shaped. The material of the eighth seal 78A is synthetic resin or rubber. The eighth seal 78A is disposed in an eighth seal arrangement portion 78B. The eighth seal arrangement portion 78B is provided on the first inner circumferential surface 47A.

[0126] The press device 11 has a ninth seal 79A. The ninth seal 79A is a seal for preventing oil in the sixth pressure chamber 49 from leaking to the outside through the second additional cylinder through hole 47C when the second cylindrical piston rod 39 operates. The ninth seal 79A is ring-shaped. The material of the ninth seal 79A is synthetic resin or rubber. The ninth seal 79A is disposed in a ninth seal arrangement portion 79B. The ninth seal arrangement portion 79B is provided on the second cylindrical piston rod outer circumferential surface 39B.

[0127] The press device 11 has a tenth seal 80A. The tenth seal 80A, together with the ninth seal 79A, is a seal for preventing oil in the sixth pressure chamber 49 from leaking to the outside through the second additional cylinder through-hole 47C when the second cylindrical piston rod 39 moves. The tenth seal 80A is ring-shaped. The material of the tenth seal 80A is synthetic resin or rubber. The tenth seal 80A is disposed in the tenth seal arrangement portion 80B. The tenth seal arrangement portion 80B is provided in the second additional cylinder through-hole 47C.

[0128] <Wearing> The press device 11 has one or more fourth wear rings 84A. The fourth wear ring 84A is a bearing material for guiding the second additional piston 37 to move along the second additional cylinder 47 when the second additional piston 37 moves. The fourth wear ring 84A is cylindrical. The material of the fourth wear ring 84A is synthetic resin. The fourth wear ring 84A is arranged in the fourth wear ring arrangement portion 84B. The fourth wear ring arrangement portion 84B is provided on the first inner circumferential surface 47A. In one example, the fourth wear ring arrangement portion 84B is provided in a portion of the first inner circumferential surface 47A that is farther from the second die 13 than the eighth seal arrangement portion 78B. The arrangement and number of the fourth wear ring 84A are not limited to this example.

[0129] The press device 11 has one or more fifth wear rings 85A. The fifth wear ring 85A, together with the fourth wear ring 84A, is a bearing material for guiding the second additional piston 37 to move along the second additional cylinder 47 when the second additional piston 37 moves. The fifth wear ring 85A is cylindrical. The material of the fifth wear ring 85A is synthetic resin. The fifth wear ring 85A is arranged on the fifth wear ring arrangement portion 85B. The fifth wear ring arrangement portion 85B is provided on the second additional piston outer circumferential surface 38B. In one example, the fifth wear ring arrangement portion 85B is provided on a portion of the second additional piston outer circumferential surface 38B that is farther from the second die 13 than the seventh seal arrangement portion 77B. The arrangement and number of the fifth wear ring 85A are not limited to this example.

[0130] <Control Unit> As in the first embodiment, the control unit 91 controls the hydraulic device 51 so that the piston 31 operates via the first hydraulic system 52. As in the first embodiment, the control unit 91 controls the hydraulic device 51 so that the first additional piston 34 operates via the second hydraulic system 53. The control unit 91 controls the hydraulic device 51 so that the second additional piston 37 operates via the third hydraulic system 62.

[0131] The control unit 91 is configured to control the hydraulic device 51 so that, when the second mold 13 is moved in the first direction Z1, one of the piston 31, the first additional piston 34, and the second additional piston 37 moves faster than the remaining two of the piston 31, the first additional piston 34, and the second additional piston 37. In this embodiment, when the second mold 13 is moved in the first direction Z1, the control unit 91 controls the hydraulic device 51 so that the first additional piston 34 fixed to the second mold 13 moves faster than the piston 31 and the second additional piston 37. This makes it possible to suppress frequent occurrence of the above-mentioned bubble generation state.

[0132] When the second mold 13 is moved in the second direction Z2, the control unit 91 controls the hydraulic device 51 so that two of the piston 31, the first additional piston 34, and the second additional piston 37 move faster than the remaining one of the piston 31, the first additional piston 34, and the second additional piston 37. In this embodiment, when the second mold 13 is moved in the second direction Z2, the control unit 91 controls the hydraulic device 51 so that the piston 31 and the second additional piston 37 that are not fixed to the second mold 13 move faster than the first additional piston 34. This makes it possible to suppress frequent occurrence of the above-mentioned bubble generation state.

[0133] In the press device 11 of the second embodiment, pressure is applied to the second surface 13B of the second die 13 at two points, approximately the center and the outer side, by the piston 31, the first additional piston 34, and the second additional piston 37, eliminating the deflection of the second die 13 that occurs when the second die 13 contacts the first die 12. This makes it easier to apply uniform pressure to the entire surface of the workpiece 21. This allows the workpiece 21 to be crimped with high precision.

[0134] (Effects of the second embodiment) The effects of the second embodiment will be described. (1) In addition to the piston 31 and the first additional piston 34, the press device 11 further includes a second additional piston 37 that cooperates with the piston 31 and the first additional piston 34 to move the second die 13. The second additional piston 37 is a cylindrical body, and has a third central axis C3 that is coaxial with the first central axis C1 and the second central axis C2, and a second through hole 37A that extends in a direction along the third central axis C3. The piston 31 and the first additional piston 34 are disposed within the second through hole 37A.

[0135] According to this configuration, pressure can be applied to the workpiece 21 by the piston 31, the first additional piston 34, and the second additional piston 37 in an appropriate manner.

[0136] (2) One of the piston 31, the first additional piston 34, and the second additional piston 37 is fixed to the second mold 13, and the remaining two of the piston 31, the first additional piston 34, and the second additional piston 37 are movable relative to the second mold 13.

[0137] According to this configuration, when the piston 31, the first additional piston 34, and the second additional piston 37 are operated so as to move the second mold 13 toward the first mold 12, the generation of air bubbles in the cylinders 41, 42, 47 supporting these pistons 31, 34, 37 can be suppressed.

[0138] (3) The hydraulic device 51 is configured to move the piston 31, the first additional piston 34, and the second additional piston 37 independently of each other. The hydraulic device 51 further includes a control unit 91 configured to control the hydraulic device 51. The control unit 91 is configured to control the hydraulic device 51 such that, when the workpiece 21 is pressurized, the pressurization timing of one of the piston 31, the first additional piston 34, and the second additional piston 37 is different from the pressurization timing of the remaining two of the piston 31, the first additional piston 34, and the second additional piston 37.

[0139] According to this configuration, the first die 12 and the second die 13 can apply pressure to the workpiece 21 being pressed in different ways.

[0140] Third embodiment A press device 11 according to a third embodiment will be described with reference to Fig. 6. In the third embodiment, differences from the first embodiment will be described. Members similar to those in the first embodiment will be given the same names and will not be described.

[0141] <Using device> 6, the pressing device 11 further includes a biasing device 100. The biasing device 100 biases the piston 31 and the first additional piston .

[0142] The biasing device 100 has a first biasing part 101 and a second biasing part 102. The first biasing part 101 is a metal spring, a rubber spring, an air spring, or a liquid spring. The first biasing part 101 is provided in the internal space S. The first biasing part 101 is provided between the piston 31 and the cylinder 41. The first biasing part 101 biases the piston 31 so as to move in a second direction Z2 in which the second die 13 moves away from the first die 12. Specifically, the first biasing part 101 is provided in a portion corresponding to the second pressure chamber 44 of the first embodiment.

[0143] The second biasing portion 102 is a metal spring, a rubber spring, an air spring, or a liquid spring. The second biasing portion 102 is provided in the first internal space S1. The second biasing portion 102 is provided between the first additional piston 34 and the first additional cylinder 42. The second biasing portion 102 biases the first additional piston 34 so as to move the second die 13 in a second direction Z2 away from the first die 12. Specifically, the second biasing portion 102 is provided in a portion corresponding to the fourth pressure chamber 46 of the first embodiment.

[0144] The biasing device 100 may further include a first actuator 103 and a second actuator 104. The first actuator 103 is an air actuator, an electric actuator, or a hydraulic actuator. The first actuator 103 is provided on the first cylindrical piston rod 33. The first actuator 103 biases the piston 31 together with the first biasing portion 101 so as to move the second die 13 in a second direction Z2 away from the first die 12.

[0145] The second actuator 104 is an air actuator, an electric actuator, or a hydraulic actuator. The second actuator 104 is provided on the piston rod 36. The second actuator 104, together with the second biasing portion 102, biases the first additional piston 34 so as to move the second die 13 in the second direction Z2 away from the first die 12.

[0146] The biasing device 100 may include a linear scale or linear encoder for the piston 31. The biasing device 100 may include a linear scale or linear encoder for the first additional piston .

[0147] (Effects of the third embodiment) The effects of the third embodiment will be described. (1) The apparatus further includes a biasing device 100 that biases the piston 31 and the first additional piston 34. The biasing device 100 has a first biasing section 101 that biases the piston 31 in the cylinder 41 so that the second die 13 moves in a second direction Z2 away from the first die 12, and a second biasing section 102 that biases the first additional piston 34 in the first additional cylinder 42 so that the second die 13 moves in the second direction Z2.

[0148] According to this configuration, the piston 31 and the first additional piston 34 can be operated by the biasing portion so that the second mold 13 moves in the second direction Z2. In addition, by providing the highly elastic first biasing portion 101 and second biasing portion 102, the mold opening speed can be improved.

[0149] <Example of change> The press device of the present disclosure may have the following modified examples other than the above-described embodiment, or may have a configuration in which at least two modified examples that are not mutually contradictory are combined.

[0150] In the first embodiment, the first additional piston 34 is fixed to the second mold 13, and the piston 31 is movable relative to the second mold 13. In contrast, the first additional piston 34 may be movable relative to the second mold 13, and the piston 31 may be fixed to the second mold 13. In this case, in the movement in the first direction Z1, the piston 31 fixed to the second mold 13 is controlled to move earlier in timing than the first additional piston 34 movable relative to the second mold 13. This allows pressure to be applied to the periphery of the work 21 before the center. In addition, frequent occurrence of a bubble generation state can be suppressed. In the movement in the second direction Z2, the first additional piston 34 movable relative to the second mold 13 is controlled to move earlier in timing than the piston 31 fixed to the second mold 13. This allows frequent occurrence of a bubble generation state to be suppressed.

[0151] In the first embodiment, both the piston 31 and the first additional piston 34 do not have to be fixed to the second mold 13. In this case, it is preferable that the second mold 13 is biased toward the piston 31 and the first additional piston 34 with a predetermined force. With this configuration, even if there is variation in the operation of the piston 31 and the first additional piston 34, it is possible to suppress the generation of air bubbles.

[0152] In the second embodiment, among the piston 31, the first additional piston 34, and the second additional piston 37, only the first additional piston 34 is fixed to the second die 13. In contrast, only the second additional piston 37 may be fixed to the second die 13. In this case, in the movement in the first direction Z1, the second additional piston 37 fixed to the second die 13 is controlled to move earlier in timing than the piston 31 and the first additional piston 34 which are movable relative to the second die 13. Furthermore, in the movement in the first direction Z1, the piston 31 is controlled to move earlier in timing than the first additional piston 34. In this way, by moving these pistons in order from the outside, that is, in the order of the second additional piston 37, the piston 31, and the first additional piston 34, pressure can be applied in sequence from the outer periphery of the workpiece 21 toward the center.

[0153] In the second embodiment, the following control may be performed. In the movement in the first direction Z1, the first additional piston 34 fixed to the second die 13 is controlled to move earlier in timing than the piston 31 and the second additional piston 37 which are movable relative to the second die 13. Furthermore, in the movement in the first direction Z1, the piston 31 is controlled to move earlier in timing than the second additional piston 37. In this way, by moving these pistons in order from the inside, that is, in the order of the first additional piston 34, the piston 31, and the second additional piston 37, pressure can be applied in order from the center of the workpiece 21 toward the outer periphery.

[0154] In the second embodiment, the piston 31, the first additional piston 34, and the second additional piston 37 do not all have to be fixed to the second mold 13. In this case, it is preferable that the second mold 13 is biased with a predetermined force toward the piston 31, the first additional piston 34, and the second additional piston 37. With this configuration, even if there is variation in the operation of the piston 31, the first additional piston 34, and the second additional piston 37, it is possible to suppress the generation of air bubbles.

[0155] The number of pistons in the press device 11 is not limited. The press device 11 may have three or more cylindrical pistons sharing a common central axis. The press device 11 may also have three or more cylindrical pistons sharing a common central axis, and a columnar piston sharing a common central axis with the cylindrical pistons.

[0156] In the first embodiment, the first speed V1 may be equal to the second speed V2. When the first speed V1 is equal to the second speed V2, the control unit 91 controls the hydraulic device 51 so that one of the piston 31 and the first additional piston 34, which is fixed to the second mold 13, moves before the other of the piston 31 and the first additional piston 34.

[0157] Each of the ports 55, 56, 59, 60, 64, and 65 may be connected to a different hydraulic pump or to the same hydraulic pump.

[0158] In each embodiment, the form of the hydraulic device 51 is not limited. A servo-controlled pump device can be used as the hydraulic device 51. The servo-controlled pump device can control the flow rate and flow direction by a servo motor. The servo-controlled pump device can control the movement of the piston with high precision. In addition, the servo-controlled pump device can switch the direction of the oil flow by switching the rotation direction of the motor between forward and reverse, so that a switching valve can be omitted. In the servo-controlled pump device, the oil flow direction can be switched based on the switching of the rotation direction of the motor between forward and reverse, so that the switching operation from the first direction Z1 to the second direction Z2 of the second die 13 can be smoothly performed.

[0159] The present specification discloses the following techniques: [Appendix 1] Supplementary Note 1 is a technique related to a press device. The press device includes a first die, a second die that moves relative to the first die, and a piston that moves the second die. The piston has an annular pressing surface that presses the second die. The piston is a cylinder. The piston has a first central axis and a first through hole that extends in a direction along the first central axis. The press device further includes a first additional piston that moves the second die in cooperation with the piston. The first additional piston is a cylinder or column, has a second central axis that is coaxial with the first central axis, and is disposed within the first through hole. Both the piston and the first additional piston are not fixed to the second die and are movable relative to the second die. [Appendix 2] In addition, the hydraulic device may further include a hydraulic device that moves the piston and the first additional piston independently of each other.

[0160] The description of each embodiment is merely an example of a form that the press apparatus according to the present disclosure can take, and is not intended to limit the form. The press apparatus according to the present disclosure can take other forms different from the forms exemplified in each embodiment. [Explanation of symbols]

[0161] Reference Signs List: 11...press device, 12...first die, 13...second die, 21...workpiece, 31...piston, 31A...first through hole, 33C...pressing surface, 34...first additional piston, 37...second additional piston, 37A...second through hole, 41...cylinder, 42...first additional cylinder, 51...hydraulic device, 52...first hydraulic system, 53...second hydraulic system, 91...control unit, 100...urging device, 101...first urging section, 102...second urging section, C1...first central axis, C2...second central axis, C3...third central axis, Z1...first direction, Z2...second direction.

Claims

1. A press device for pressing a workpiece, Type 1 and A second mold that moves relative to the first mold; a cylindrical piston for moving the second die; and a first additional piston for moving the second die in a cylindrical or columnar shape in cooperation with the piston; the piston has a surface that contacts the second die and is annular and has one pressing surface that presses the second die, a first central axis, and a first through hole that extends in a direction along the first central axis, the first additional piston has a second central axis coaxial with the first central axis and a first additional pressing surface that is a surface in contact with the second die and presses the second die, and is disposed within the first through hole; Press equipment.

2. one of the piston and the first additional piston is fixed to the second mold; the other of the piston and the first additional piston is movable relative to the second mold; The press device according to claim 1 .

3. Further comprising a hydraulic device for moving the piston and the first additional piston independently of each other. The press device according to claim 2 .

4. A cylinder supporting the piston; a first additional cylinder supporting the first additional piston; The hydraulic device includes a first hydraulic system that moves the piston in the cylinder so that the second die moves in a first direction toward the first die, and a second hydraulic system that moves the first additional piston in the first additional cylinder so that the second die moves in the first direction. The press device according to claim 3.

5. The piston and the first additional piston are further provided with a biasing device. the biasing device includes a first biasing portion that biases the piston in the cylinder so that the second die moves in a second direction away from the first die, and a second biasing portion that biases the first additional piston in the first additional cylinder so that the second die moves in the second direction. The pressing device according to claim 4.

6. A control unit for controlling the hydraulic device is further provided. The control unit controls the hydraulic device such that, when the workpiece is pressurized, a pressurization timing of one of the piston and the first additional piston is different from a pressurization timing of the other of the piston and the first additional piston.

6. A press apparatus according to claim 4 or 5.

7. a second additional piston that cooperates with the piston and the first additional piston to move the second mold; the second additional piston is a cylindrical body, and has a third central axis that is coaxial with the first central axis and the second central axis, and a second through hole that extends in a direction along the third central axis, the piston and the first additional piston are disposed in the second through hole; The pressing device according to claim 4.

8. one of the piston, the first additional piston, and the second additional piston is fixed to the second mold; the remaining two of the piston, the first additional piston, and the second additional piston are movable relative to the second mold; The pressing device according to claim 7.

9. the hydraulic device is configured to move the piston, the first additional piston, and the second additional piston independently of one another; a controller configured to control the hydraulic device; The control unit is configured to control the hydraulic device such that, when a workpiece is pressurized, a pressurization timing of one of the piston, the first additional piston, and the second additional piston is different from a pressurization timing of the remaining two of the piston, the first additional piston, and the second additional piston. The pressing device according to claim 8.

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