PRESSING DEVICE

Abstract

Pressing device (1), comprising: a pressing device main body (90) comprising: a carriage (2) arranged to have an upper die (7) mounted thereon; a table (3) arranged below the carriage (2), the table (3) being arranged such that a lower die (8) is arranged thereon; a servo motor (21) arranged to drive the carriage (2); an energy storage unit (42) configured to supply the servo motor (21) with stored energy; a discharge unit (11) configured to discharge charge stored in the energy storage unit (42); and a first contactor (13) configured to interrupt an electrical connection between the energy storage unit (42) and the discharge unit (11) in an energized state and to electrically connect the energy storage unit (42) and the discharge unit (11) in a non-energized state; and a main circuit breaker (9) configured to supply or stop the press device main body (90) with power from an external power supply (100), wherein power for energization is supplied to the first contactor (13) from the external power supply (100) without passing through the main circuit breaker (9).

Description

TECHNICAL AREA

[0001] The present invention relates to a pressing device. STATE OF THE ART

[0002] For example, automobile manufacturers produce body panels and the like using a press device that uses molds / die sets. In recent years, servo-motor-driven press machines have been used as press devices.

[0003] In such a servo motor driven press machine, the peak power during press forming is quite high, and problems such as flickering may occur due to voltage drop inside or outside the factory.

[0004] Therefore, a structure has been disclosed in which an aluminum electrolytic capacitor is installed in a pressing device to keep the peak power low (see JP 2003-230997 A). PATENT LITERATURE

[0005] JP 2003- 230 997 A, JP 2009- 148 130 A, US 2010 / 0 192 788 A1. SUMMARY

[0006] However, in a conventional pressing device, when the power is turned off, the charge stored in the energy storage unit is forcibly discharged, so energy is wasted.

[0007] It is an object of the present invention to provide a pressing device with which energy can be saved. PROBLEM SOLVING

[0008] To achieve the stated object, the press device according to the present invention comprises a press device main body and a main circuit breaker. The press device main body has a carriage, a table, a servo motor, an energy storage unit, a discharge unit, and a first contactor. The upper die can be mounted on the carriage. The table is arranged below the carriage, and the lower die can be placed thereon. The servo motor drives the carriage. The energy storage unit can supply stored energy to the servo motor. The discharge unit discharges the charge stored in the energy storage unit. In an energized state, the first contactor interrupts the electrical connection between the energy storage unit and the discharge unit, and in a de-energized state, it electrically connects the energy storage unit and the discharge unit.The main disconnect switch supplies or interrupts power to the servo motor from an external power supply. The power for excitation is supplied to the contactor from the factory power supply without passing through the main disconnect switch. BENEFICIAL EFFECTS

[0009] The present invention provides a pressing device that can save energy. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a simplified view of a pressing device according to an embodiment of the present invention; Fig. 2 is an oblique view of a capacitor unit of the pressing device in Fig. 1; Fig. 3 is a flow chart of the control in a pressing operation with the pressing device in Fig. 1; and Fig. Figure 4 is a graph of the energy supplied from a factory power supply when pressing using the pressing device in Fig. 1 is carried out. DESCRIPTION OF EMBODIMENTS

[0010] The pressing device of the present invention will now be described with reference to the drawings. 1. Structure1-1. Overview of the pressing device

[0011] Fig. 1 is a simplified view of the structure of a pressing device 1 in an embodiment of the present invention.

[0012] The press device 1 in this embodiment includes a main circuit breaker 9 and a press device main body 90. The main circuit breaker 9 supplies or interrupts the supply of power from a factory power supply 100 to the press device main body 90. When the main circuit breaker 9 is connected, the power supply of the press device 1 is turned on, and when the main circuit breaker 9 is disconnected, the power supply of the press device 1 is turned off.

[0013] The pressing device main body 90 subjects a material to pressing using an upper die 7 and a lower die 8. The pressing device main body 90 mainly includes a carriage 2, a table 3, a carriage driving device 4, a servo power supply unit 5, a storage system unit 6, a control device 10, a discharge unit 11, and a contactor 13.

[0014] The upper die 7 is attached to the underside of the carriage 2. The lower die 8 is arranged on the top side of the table 3. The carriage drive device 4 moves the carriage 2 up and down. The servo power supply unit 5 converts the alternating current supplied from the factory power supply 100 into direct current and outputs it to the storage system unit 6. The storage system unit 6 stores the power supplied from the factory power supply 100 or the regenerative energy generated in the carriage drive device 4. The control device 10 controls the carriage drive device 4, the servo power supply unit 5, and the storage system unit 6. The discharge unit 11 is provided to forcibly discharge the charge stored in the capacitor unit 60. The contactor 13 closes or opens the electrical connection between the discharge unit 11 and an accumulator 42 of the storage system unit 6. 1-2. Carriage drive device

[0015] The carriage drive device 4 includes a servomotor 21, a servo amplifier 22, a pinion gear 23, a main gear 24, a crankshaft 25, and a connecting rod 26. The servomotor 21 is the drive source for the carriage 2. The servo amplifier 22 supplies drive power to the servomotor 21. The pinion gear 23 is connected to the servomotor 21 and is rotated by the rotation of the servomotor 21. The main gear 24 meshes with the pinion gear 23 and rotates together with the pinion gear 23. The crankshaft 25 is connected to the main gear 24 and is rotated by the rotation of the main gear 24. The connecting rod 26 connects the crankshaft 25 and the carriage 2. In this embodiment, two connecting rods 26 are provided.

[0016] When the servo motor 21 is rotated by the drive current from the servo amplifier 22, the pinion gear 23 rotates, and the main gear 24 also rotates along with the pinion gear 23. The crankshaft 25 is rotated by the rotation of the main gear 24, and the connecting rod 26 moves up and down. This causes the carriage 2 connected to the connecting rods 26 to move up and down. 1-3. Servo power supply

[0017] The servo power supply 5 includes a harmonic filter module 31, a reactor 32, and a PWM converter 33. The harmonic filter module 31 prevents harmonics generated in the PWM converter 33 from returning to the factory power supply 100 side.

[0018] The choke 32 and the PWM converter 33 form a chopper circuit that converts alternating current to direct current and increases the voltage. Alternating current of a specific voltage is supplied from the factory power supply 100, and direct current of a voltage higher than the specific voltage is output by the PWM converter 33. The PWM converter 33 and the servo amplifier 22 are connected by a DC bus line 14. The PWM converter 33 also monitors the voltage on the DC bus line 14. 1-4. Storage system unit

[0019] The storage system unit 6 mainly comprises the accumulator 42, which is provided with a plurality of electric double layer capacitors 601 (see Fig. 2, described below), an initial charging circuit 41 that charges the electric double-layer capacitors 601 before operation, and a short-circuit contactor 43 that bypasses the initial charging circuit 41, and a contactor 44 that interrupts the power supply from the electric double-layer capacitors 601 to the servo motor 21. 1-4-1. Initial charging circuit

[0020] The initial charging circuit 41 is provided on the DC bus line 14 and is a circuit for charging the electric double-layer capacitors 601 (described below) provided on the secondary battery 42. That is, since the electric double-layer capacitors 601 of the secondary battery 42 are not charged before the pressing device 1 is operated, they are charged with the power supplied from the factory power supply 100. The initial charging circuit 41 includes a DC / DC converter 51 and a reactor 52. The initial charging circuit 41 throttles the current so that it does not flow into the electric double-layer capacitors 601 all at once during charging. 1-4-2. Short-circuit contactor

[0021] The short-circuit contactor 43 is provided on a bypass line 15 connected to the DC bus line 14 to bypass the initial charging circuit 41. That is, the bypass line 15 is connected to the DC bus line 14 on the PWM converter 33 side, and is connected to the DC bus line 14 on the servo amplifier 22 side of the initial charging circuit 41. When the short-circuit contactor 43 is turned on, the current output from the PWM converter 33 bypasses the initial charging circuit 41 and is supplied to the servo amplifier 22. 1-4-3. Accumulator

[0022] The accumulator 42 has four capacitor units 60, which are provided with 24 electrical double-layer capacitors 601 (see Fig. 2).

[0023] Fig. Figure 2 is a view of a capacitor unit 60 provided on the accumulator 42. In this embodiment, the capacitor unit 60 includes two heat sinks 602 and 24 series-connected electric double-layer capacitors 601.

[0024] The two heat sinks 602 are arranged one above the other. In the capacitor unit 60, a heat sink 602 and twelve electric double-layer capacitors 601 mounted on the heat sink 602 are provided in two layers. The two heat sinks 602 and the 24 electric double-layer capacitors 601 are fixed by a frame member or the like. The heat sinks 602 are plate-shaped members formed of aluminum, and channels through which cooling water flows are formed in the heat sink 602. The cooling water is supplied from a radiator 12 to the channels of the heat sinks 602. The cooling water is circulated through the radiator 12.

[0025] In the pressing device 1 in this embodiment, as shown in Fig. 1, four capacitor units 60 are provided, and the four capacitor units 60 are connected in parallel to a line (specifically, the DC bus line 14) that supplies power to the servo motor 21 from the factory power supply 100. More specifically, the four capacitor units 60 are coupled between the servo amplifier 22 and the part of the DC bus line 14 to which the bypass line 15 is connected. Incidentally, in this specification, reference to the voltage of the electric double-layer capacitors 601 indicates the voltage of one capacitor unit 60 (24 electric double-layer capacitors 601 connected in series).

[0026] The four capacitor units 60 are connected to the DC bus line 14 via a connecting line 16. The connecting line 16 has a common line 161 connected to the DC bus line 14 and individual lines 162 connecting the capacitor units 60 and the common line 161. 1-4-4. Schütz

[0027] The contactor 44 is provided on the common line 161 and is a normally open type. The contactor 44 includes a movable contact 441, an excitation coil 442, and a fixed contact 443. The movable contact 441 is configured to be in contact with or separated from the fixed contact 443 connected to the common line 161.

[0028] An excitation line 17 for exciting the excitation coil 442 is connected to a second control power supply unit 81. The second control power supply unit 81 is connected via a line 82 to a first power supply line 18 connecting the main circuit breaker 9 and the servo power supply unit 5. The second control power supply unit 81 receives power from the factory power supply 100 via the main circuit breaker 9, and direct current is generated in the second control power supply unit 81. The second control power supply unit 81 supplies DC power to the excitation coil 442 in accordance with a command from the control device 10.

[0029] When the excitation coil 442 is not energized (de-energized state), the movable contact 441 is separated from the fixed contact 443, and the common line 161 is interrupted. Consequently, the electrical connection between the four capacitor units 60 and the DC bus line 14 is interrupted.

[0030] When the excitation coil 442 is energized (energized state), the movable contact 441 is in contact with the fixed contact 443, and the common line 161 is connected. Consequently, the four capacitor units 60 and the DC bus line 14 are electrically connected.

[0031] While the main circuit breaker 9 is connected and the pressing device 1 is used, the second control power supply unit 81 supplies the excitation coil 442 based on a command from the control device 10, so that the four capacitor units 60 and the DC bus line 14 are electrically connected, and power is exchanged between the capacitor units 60 and the DC bus line 14.

[0032] On the other hand, when the use of the pressing device 1 is completed, the second control power supply unit 81 stops the excitation of the excitation coil 442 based on a command from the control device 10. The excitation coil 442 enters its de-energized state, and the four capacitor units 60 and the DC bus line 14 are electrically disconnected. This prevents the electric charge stored in the capacitor units 60 from being discharged from the resistors provided on the servo amplifier 22 or the like via the connection line 16 and the DC bus line 14 when the pressing device 1 is used.

[0033] Since the power supply from the plant power supply 100 to the second control power supply unit 81 is also stopped when the main circuit breaker 9 is opened, the power flow from the second control power supply unit 81 to the excitation coil 442 is also stopped regardless of a command from the control device 10. Accordingly, the four capacitor units 60 and the DC bus line 14 are electrically disconnected. 1-5. Discharge unit, contactor

[0034] The discharge unit 11 has a resistor and is provided to forcibly discharge the electrical charge stored in the capacitor units 60. The discharge unit 11 is connected to the common line 161 via a discharge line 19.

[0035] The contactor 13 is provided on the discharge line 19 and is a normally closed type. The contactor 13 includes a movable contact 131, an excitation coil 132, and a fixed contact 133. The movable contact 131 is provided so that it can be in contact with and separated from the fixed contact 133 connected to the discharge line 19.

[0036] An excitation line 20 for exciting the excitation coil 132 is connected to the first control power supply unit 83. The first control power supply unit 83 is connected via an excitation line 84 to a second power supply line 101, which connects the factory power supply 100 and the main disconnect switch 9. Power is supplied directly from the factory power supply 100 to the first control power supply unit 83 without passing through the main disconnect switch 9. An alternating current is generated at the first control power supply unit 83, and DC power is supplied to the excitation coil 132 from the first control power supply unit 83.

[0037] In a state where the excitation coil 132 is energized (in an energized state), the movable contact 131 is separated from the fixed contact 133, and the discharge line 19 is interrupted. Consequently, the electrical connection between the four capacitor units 60 and the discharge unit 11 is interrupted.

[0038] When the excitation coil 132 is not energized (in a non-energized state), the movable contact 131 is in contact with the fixed contact 133. Consequently, the four capacitor units 60 and the discharge unit 11 are electrically connected. Therefore, the electric charge stored in the four capacitor units 60 is discharged via the discharge unit 11.

[0039] When the main circuit breaker 9 is closed and the pressing device 1 is operating, AC power is supplied to the first control power supply unit 83 from the factory power supply 100, and DC power is supplied to the excitation coil 132 from the first control power supply unit 83. Accordingly, the excitation coil 132 is in an energized state, and the electrical connection between the capacitor units 60 and the discharge unit 11 is interrupted. Even when the use of the pressing device 1 comes to an end and the main circuit breaker 9 is interrupted, power is still supplied from the second power supply line 101, so that AC power is supplied to the first control power supply unit 83 regardless of the interruption of the main circuit breaker 9, and DC power is supplied to the excitation coil 132 from the first control power supply unit 83. This puts the excitation coil 132 in an energized state.Therefore, even when the main circuit breaker 9 is cut off and the power supply to the press device main body 90 is stopped (when the power supply to the press device 1 is turned off), the electrical connection between the capacitor unit 60 and the discharge unit 11 is cut off, so that the charge stored in the capacitor units 60 is not discharged via the discharge unit 11.

[0040] This prevents the electric charge stored in the capacitor units 60 when the pressing device 1 has been used from being discharged via the discharge unit 11 when the power supply of the pressing device 1 is turned off.

[0041] Should a problem occur in the pressing device 1 and a repair, maintenance, or the like be performed, the charge stored in the capacitor units 60, for example, must be discharged. The power supply to the excitation coil 132 can be interrupted by switching off the factory power supply 100, so that this discharge can be performed. 1-6. Control device

[0042] Once the voltage of the electric double-layer capacitors 601 generated by the PWM converter 33 of the servo power supply unit 5 reaches a predetermined voltage, the control device 10 turns on the short-circuit contactor 43 and sets the bypass line 15 to its connected state. The control device 10 outputs a signal to the servo amplifier 22 according to the set movement, thereby controlling the up and down operation of the carriage 2. Furthermore, the control device 10 transmits a command to the second control power supply unit 81 and controls the supply and interruption of power from the second control power supply unit 81 to the excitation coil 442. 2. Operation

[0043] The operation of the pressing device 1 in an embodiment of the present invention will now be described. Fig. 3 is a flowchart of the operation of the pressing device 1.

[0044] First, in step S1, Fig. 3 the main disconnect switch 9 is connected.

[0045] Next, in step S2, it is detected whether or not a press-operation-ready signal is output from the control device 10. The press-operation-ready signal is a signal output by the user pressing a key when the press device 1 is operated, and is a signal indicating that the press device 1 is ready for normal operation. On the other hand, if no press-operation-ready signal is output in step S2, control proceeds to step S17, and in step S17, it is determined whether or not the main circuit breaker 9 is open. If the main circuit breaker 9 is not open, control returns to step S2. Thus, in step S2, it is determined whether a press-operation-ready signal is output until the main circuit breaker 9 is open and the power to the press device 1 is turned off.

[0046] Next, in step S3, a command is transmitted from the control device 10 to the second control power supply unit 81, and the second control power supply unit 81 supplies DC power generated using the AC power from the factory power supply 100 to the excitation coil of the contactor 44. Consequently, the movable contact 441 comes into contact with the fixed contact 443, and the capacitor unit 60 and the DC bus line 14 are electrically connected.

[0047] Power is supplied to the first control power supply unit 83 via the second power supply line 101 and the power supply line 84. The first control power supply unit 83 generates DC power based on the supplied AC power, and the thus generated DC power is supplied to the excitation coil 132 of the contactor 13. Therefore, the excitation coil 132 is in an excited state, and the electrical connection between the capacitor units 60 and the discharge unit 11 is interrupted.

[0048] Next, in step S4, the electric double-layer capacitors 601 are charged. Since the short-circuit contactor 43 is in its off state, no current flows through the bypass line 15, and the power output from the PWM converter 33 flows to the initial charging circuit 41. The electric charge is accumulated in the electric double-layer capacitors 601 connected to the DC bus line 14, while current control is performed by the DC / DC converter 51 of the initial charging circuit 41. The DC / DC converter 51 monitors the voltage of the DC bus line 14, and in step S5, charging is performed until the voltage of the electric double-layer capacitors 601 is raised to a certain level. The DC / DC converter 51 determines that charging is complete when the input voltage and the output voltage match and stops operation.

[0049] If it is detected in step S5 that the voltage of the electric double-layer capacitors 601 has been raised to a certain level by the DC / DC converter 51, the control device 10 connects the short-circuit contactor 43 in step S6. As a result, the output of the PWM converter 33 bypasses the initial charging circuit 41 and is supplied to the servo amplifier 22, and the charging and discharging of the electric double-layer capacitors 601 is started in step S11.

[0050] When the short-circuit contactor 43 is connected in step S6, the control device 10 energizes the servo motor 21 in step S7.

[0051] Next, in step S8, the servo motor 21 moves the carriage 2 up and down according to the set movement. During the downward movement of the carriage 2, the servo motor 21 accelerates to a predetermined speed, after which it is driven at a constant speed. Along with the rotation of the crankshaft 25 driven by the servo motor 21, the carriage 2 rises after reaching the bottom dead center. Then, the servo motor 21 decelerates from a predetermined position to stop the carriage 2 at the top dead center.

[0052] If a signal to stop the servo motor 21 is output in step S9, the servo motor 21 stops in step S10. As a result, the carriage 2 stops at the top dead center.

[0053] The change in energy consumption during pressing is calculated with reference to Fig. 4 described. Fig. Figure 4 is a graph of the energy change during pressing. A dotted line L1 and a solid line L2 are shown in Fig. 4. The dashed line L1 indicates the temporal change in the energy consumption of the pressing device 1 during pressing. The solid line L2 indicates the temporal change in the energy supplied by the plant power supply 100.

[0054] The downward movement of the carriage 2 begins at time t1 in Fig. 4. During the period from t1 to t2, the servo motor 21 accelerates until it reaches a predetermined speed, and the servo motor 21 consumes power. As power is consumed by the servo motor 21 and the voltage of the DC bus line 14 decreases, a preset constant power is supplied from the servo power supply unit 5. As shown by the solid line L2, since only a constant power is supplied from the servo power supply unit 5, any shortfall is supplied by the electric double-layer capacitors 601. That is, any amount exceeding the solid line L2 in the dashed line L1 is supplied by the electric double-layer capacitors 601.

[0055] When the speed of the servo motor 21 reaches a predetermined speed at time t2, the servo motor 21 is driven at a constant speed from time t2. Since the load on the servo motor 21 is small from time t2 to time t3 when the upper die 7 comes into contact with the material (workpiece), the power consumption indicated by the dotted line L1 is also small. At this point, the electric double-layer capacitors 601 are charged with the electric energy exceeding the dotted line L1 in the solid line L2.

[0056] Next, at time t3, the carriage 2 is further lowered, and pressing is performed on the workpiece until time t4. The power consumption is highest at this time, but as described above, a preset constant power is supplied from the servo power supply unit 5, and any shortfall in power is supplied from the electric double-layer capacitors 601.

[0057] When the carriage 2 reaches a predetermined position, the control device 10 decelerates the servo motor 21 to stop the carriage 2 at the top dead center. The time t5 in Fig. 4 indicates the deceleration start time of the servo motor 21, and time t6 indicates the end of this deceleration. As shown in Fig. As shown in Figure 4, the output power is on the negative side from time t5 to t6, and regenerative energy is generated in the servo motor 21. This regenerative energy is used to charge the electric double-layer capacitors 601.

[0058] On the other hand, during the press processing of steps S14 to S17, the control of steps S11 to S15 is performed in parallel. As described above, the charging and discharging of the electric double-layer capacitors 601 is started in step S11 when the short-circuit contactor 43 is connected in step S6.

[0059] Then, in the next step S12, the PWM converter 33 determines whether the voltage of the DC bus line 14 is at or above a predetermined level. If the voltage of the DC bus line 14 is at or above the predetermined level, control proceeds to step S13, and the energy is regenerated to the factory power supply 100 through the energy recovery function of the PWM converter 33. Since the voltage of the DC bus line 14 is equal to the voltage of the electric double-layer capacitors 601, the PWM converter 33 detects the voltage of the electric double-layer capacitors 601. That is, when the charge amount of the electric double-layer capacitors 601 is at or above a predetermined level, the regenerative energy generated by the servo motor 21 is sent to the factory power supply 100.In addition, when the voltage of the DC bus line 14 is lower than the predetermined voltage in step S12, the electric double layer capacitors 601 are charged in step S14.

[0060] Next, in step S15, it is detected whether or not a press-ready signal is output from the control device 10. While the press-ready signal is being detected, steps S11 to S14 are repeated.

[0061] After the electric double-layer capacitors 601 are charged for the first time, they are charged by regenerative energy generated during the deceleration of the servo motor 21 or the like. For this reason, charging from the factory power supply 100 does not need to be performed.

[0062] As described above, since the chargeable electric double layer capacitors 601 are provided, any energy shortage is supplied from the electric double layer capacitors 601, so that, as shown in Fig. 4, the energy supplied by the plant power supply 100 can be kept constant.

[0063] On the other hand, if it is determined in step S15 that no press operation ready signal is output from the control device 10, the control proceeds to step S16.

[0064] Next, in step S16, the control device 10 transmits a command to the second control power supply unit 81, and the second control power supply unit 81 cuts off the power supply to the excitation coil 442. As a result, the movable contact 441 is separated from the fixed contact 443, and the capacitor units 60 and the DC bus line 14 are electrically disconnected.

[0065] Next, in step S17, if the main breaker 9 is open, the power supply to the pressing device 1 is turned off. If the main breaker 9 is not open in step S17, control proceeds to step S2, and it is confirmed whether a press-ready signal is output in step S2 as described above. If no press-ready signal is output, control returns to step S17. Thus, steps S2 and S17 are repeated until a press-ready signal is output or the main breaker 9 is open.

[0066] Thus, since the capacitor units 60 are separated from the DC bus line 14, it is possible to prevent the electric charge generated by the regenerative energy from being discharged from the resistors provided on the servo amplifier 22 and the like.

[0067] Meanwhile, power is supplied to the first control power supply unit 83 from the second power supply line 101 and the excitation line 84, and power is supplied to the contactor 13 from the first control power supply unit 83 via the excitation line 20. The excitation coil 132 is in its energized state regardless of the interruption of the main circuit breaker 9. Even if the main circuit breaker 9 is interrupted and the power supply to the press device main body 90 is stopped (even if power to the press device 1 is cut off), the electrical connection between the capacitor units 60 and the discharge unit 11 is interrupted.

[0068] Since the capacitor units 60 are thus separated from the discharge unit 11, it is possible to prevent the discharge unit 11 from discharging the charge generated by regenerative energy.

[0069] As described above, the discharge from the electric double-layer capacitors 601 is kept to a minimum in a state where the power supply to the pressing device 1 is turned off. Therefore, when the pressing device 1 is turned on next time and pressing is performed, only a small charge is required when performing capacitor charging in step S4, and power consumption can be reduced. 3. Features etc. (3-1)

[0070] The pressing device 1 in this embodiment includes the pressing device main body 90 and the main circuit breaker 9. The pressing device main body 90 includes the carriage 2, the table 3, the servo motor 21, the accumulator 42 (an example of an energy storage unit), the discharge unit 11, and the contactor 13 (an example of a first contactor). The upper die 7 can be attached to the carriage 2. The table 3 is arranged below the carriage 2, and the lower die 8 can be placed thereon. The servo motor 21 drives the carriage 2. The accumulator 42 can supply stored energy to the servo motor 21. The discharge unit 11 discharges the charge stored in the accumulator 42. The contactor 13, in an energized state, disconnects the electrical connection between the accumulator 42 and the discharge unit 11 and, in a non-energized state, electrically connects the accumulator 42 and the discharge unit 11.The main circuit breaker 9 supplies or stops the supply of power from the factory power supply 100 (an example of an external power supply) to the press machine main body 90. Power for excitation is supplied to the contactor 13 from the factory power supply 100 without passing through the main circuit breaker 9.

[0071] Consequently, even if the main circuit breaker 9 is interrupted and the power to the press device 1 is cut off, at the first control power supply unit 83, the power from the factory power supply 100 is converted from alternating current to direct current and supplied to the contactor 13, thus maintaining the energized state of the contactor 13. Therefore, the electrical connection between the accumulator 42 and the discharge unit 11 is severed, and the charge stored in the accumulator 42 is not discharged via the discharge unit 11.

[0072] Therefore, the energy stored in the accumulator 42 can be used the next time the pressing device 1 is started, so that the energy consumption can be reduced. (3-2)

[0073] In the press device 1 in this embodiment, the press device main body 90 further includes the DC bus line 14 and the contactor 44 (an example of a second contactor). The DC bus line 14 supplies power to the servo motor 21 from the factory power supply 100 (an example of an external power supply) and is electrically connected to the battery 42 (an example of an energy storage unit). The contactor 44 electrically connects the battery 42 and the DC bus line 14 in an energized state, and interrupts the electrical connection between the battery 42 and the DC bus line 14 in a de-energized state. Power for energization is supplied to the contactor 44 from the factory power supply 100 via the main circuit breaker 9.

[0074] As a result, when the contactor 44 is not energized, the electrical connection between the battery 42 and the DC bus line 14 is interrupted, and discharge of resistors or the like connected to the DC bus line 14 can be prevented. The power supply to the contactor 44 is controlled by the second control power supply unit 81 based on a command from the control device 10. Even in a state where the main circuit breaker 9 is open and the power to the pressing device 1 has been turned off, no power for energization is supplied to the second control power supply unit 81, which means that regardless of a command from the control device 10, no power for energization is supplied to the contactor 44 and the contactor 44 is in a non-energized state. (3-3)

[0075] In the pressing device 1 in this embodiment, the accumulator 42 (an example of an energy storage unit) has a plurality of electric double layer capacitors 601.

[0076] Thus, the use of the accumulator 42 including the electric double-layer capacitors 601 increases the amount of energy stored in the accumulator 42. Therefore, when the power to the press device 1 is turned off, preventing discharge increases the amount of energy that can be used when the press device 1 starts up next time and reduces energy consumption. (3-4)

[0077] In the pressing device 1 in this embodiment, the contactor 13 (an example of a first contactor) includes the movable contact 131 (an example of a first movable contact) and the excitation coil 132 (an example of a first coil). The movable contact 131 interrupts or connects the discharge line 19 (an example of a first line) connecting the battery 42 (an example of an energy storage unit) and the discharge unit 11.

[0078] The excitation coil 132 moves the movable contact 131 to interrupt the discharge line 19 in an energized state and connect the discharge line 19 in a de-energized state. The excitation coil 132 is supplied with power for excitation from the second power supply line 101 (an example of a second line) connecting the plant power supply 100 and the main circuit breaker 9.

[0079] Consequently, even when the main circuit breaker 9 is interrupted to cut off the power to the pressing device 1, the excitation coil 132 is energized, and the interruption of the electrical connection between the accumulator 42 and the discharge unit 11 can be maintained. (3-5)

[0080] In the pressing device 1 in this embodiment, the contactor 44 (an example of a second contactor) includes the movable contact 441 (an example of a second movable contact) and the excitation coil 442 (an example of a second coil). The movable contact 441 interrupts or connects the connecting line 16 (an example of a third line) that connects the DC bus line 14 and the battery 42 (an example of an energy storage unit). The excitation coil 442 moves the movable contact 441 to connect the connecting line 16 in an energized state and interrupt the connecting line 16 in a de-energized state. The excitation coil 442 is powered by the first power supply line 18 (an example of a fourth line) that supplies power to the servo motor 21 from the main breaker 9.

[0081] Consequently, in a state where the main circuit breaker 9 has been cut off and the power supply to the pressing device 1 has been turned off, the excitation of the excitation coil 442 is stopped, so that the electrical connection between the accumulator 42 and the DC bus line 14 is interrupted regardless of a command from the control device 10. 4. Other embodiments

[0082] An embodiment of the present invention has been described above, but the present invention is not limited to or by the above embodiment, and various modifications are possible without departing from the gist of the invention. (A) In the above embodiment, the contactor 44 is provided to interrupt the connection between the battery 42 and the DC bus line 14 when the main circuit breaker 9 is interrupted, but the contactor 44 may not be provided. If at least the contactor 13 is provided to interrupt the connection between the battery 42 and the discharge unit 11 when the main circuit breaker 9 is interrupted, the discharge amount can be reduced compared to the prior art. (B) In the above embodiment, the power supplied to the excitation coil 442 of the contactor 44 is supplied from the first power supply line 18, but this is not the only option. Power can be supplied to the excitation coil 442 from the factory power supply 100 via the main circuit breaker 9, and the power supply to the excitation coil 442 can be stopped together with the interruption of the main circuit breaker 9. (C) In the above embodiment, the first control power supply unit 83 and the second control power supply unit 81 generated DC power, which is supplied to the exciting coils 132 and 442, but AC power may be supplied instead. (D) In ​​the above embodiment, four capacitor units 60 in which 24 electric double layer capacitors 601 are connected in series are provided, and four capacitor units 60 are connected in parallel, but the number and connection structure are not limited thereto. (E) In the above embodiment, the electric double-layer capacitors 601 are used to store electricity, but electric double-layer capacitors are not the only option, and aluminum electrolytic capacitors or the like can be used instead. In other words, any structure that allows electrical charge to be stored can be used. INDUSTRIAL APPLICABILITY

[0083] The pressing device of the present invention has the effect that energy consumption can be reduced and is useful for, for example, a production line in a factory.

Claims

[1] Pressing device (1), comprising: a pressing device main body (90) comprising: a carriage (2) arranged to have an upper die (7) mounted thereon; a table (3) arranged below the carriage (2), the table (3) being arranged such that a lower die (8) is arranged thereon; a servo motor (21) arranged to drive the carriage (2); an energy storage unit (42) configured to supply the servo motor (21) with stored energy; a discharge unit (11) configured to discharge charge stored in the energy storage unit (42); and a first contactor (13) configured to interrupt an electrical connection between the energy storage unit (42) and the discharge unit (11) in an energized state and to electrically connect the energy storage unit (42) and the discharge unit (11) in a non-energized state; and a main circuit breaker (9) configured to supply or stop the press device main body (90) with power from an external power supply (100), wherein power for energization is supplied to the first contactor (13) from the external power supply (100) without passing through the main circuit breaker (9). [2] Pressing device (1) according to claim 1, the pressing device main body (90) further comprising: a DC bus line (14) configured to supply power from the external power supply (100) to the servo motor (21), the DC bus line (14) being electrically connected to the energy storage unit (42); and a second contactor (44) configured to electrically connect the energy storage unit (42) and the DC bus line (14) in an energized state, interrupts the electrical connection between the energy storage unit (42) and the DC bus line (14) in a non-energized state, and is supplied with energy for excitation from the external power supply (100) via the main disconnect switch (9). [3] Pressing device (1) according to claim 1 or 2, wherein the energy storage unit (42) contains a plurality of electrical double-layer capacitors (601). [4] Pressing device (1) according to one of claims 1 to 3, wherein the first contactor (13) contains: a first movable contact (131) configured to interrupt or connect a first line connecting the energy storage unit (42) and the discharge unit (11); and a first coil configured to move the first movable contact (131) to interrupt the first line in the energized state and to connect the first line in the non-energized state, and the first coil is supplied with energy for excitation via a second line connecting the external power supply (100) and the main disconnect switch (9). [5] Pressing device (1) according to claim 2, wherein the second contactor (44) includes: a second movable contact (441) configured to interrupt or connect a third line connecting the DC bus line (14) and the energy storage unit (42); and a second coil configured to move the second movable contact (441) to connect the third line in the energized state and to interrupt the third line in the non-energized state, and energy is supplied to the second excitation coil from a fourth line which supplies energy from the main circuit breaker (9) to the servo motor (21).

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