Input circuit and injection molding machine

Abstract

To realize an input circuit and an injection molding machine that can cope with both sink input formats and source input formats while preventing an increase in the number of input terminals.SOLUTION: An IO board 45 according to the present disclosure includes a pair of input terminals T1 and T2 and a switching circuit 452. A circuit configuration of the switching circuit 452 is switchable between a first circuit configuration coping with a sink input type in which a current is drawn from a load 451 to one of the pair of input terminals T1 and T2, and a second circuit configuration coping with a source input type in which a current is output from the other of the pair of input terminals T1 and T2 to the load 451.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to an input circuit and an injection molding machine. [Background technology]

[0002] Patent Document 1 discloses an injection molding machine that is provided with an input / output board between the machine and an externally connected device. In Patent Document 1, the externally connected device is provided with a sink-type input terminal or a source-type input terminal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-30603 Summary of the Invention [Problem to be solved by the invention]

[0004] If an input circuit is provided with both two input terminals corresponding to the sink input format and two input terminals corresponding to the source input format, the number of input terminals increases.

[0005] The present disclosure has been made in consideration of such problems, and provides an input circuit and an injection molding machine that are compatible with both sink input formats and source input formats while preventing an increase in the number of input terminals. [Means for solving the problem]

[0006] An input circuit according to one aspect of the present disclosure comprises a pair of input terminals and a switching circuit, and the circuit configuration of the switching circuit is switched between a first circuit configuration corresponding to a sink input format in which current is drawn from a load to one of the pair of input terminals, and a second circuit configuration corresponding to a source input format in which current is output from the other of the pair of input terminals to the load.

[0007] An injection molding machine according to one aspect of the present disclosure is an injection molding machine having an input circuit, the input circuit having a pair of input terminals and a switching circuit, the circuit configuration of the switching circuit being switchable between a first circuit configuration corresponding to a sink input format in which current is drawn from a load to one of the pair of input terminals, and a second circuit configuration corresponding to a source input format in which current is output from the other of the pair of input terminals to the load. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to realize an input circuit and an injection molding machine that are compatible with both sink input formats and source input formats while preventing an increase in the number of input terminals. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an external view of an injection molding machine 100. [Figure 2] FIG. 1 is a schematic block diagram of an injection molding machine 100. [Figure 3] 1 is a diagram showing an example of an externally connected device 101 and an example of a connection form. [Figure 4] FIG. 2 is a circuit diagram illustrating the configuration of an IO board 45. [Figure 5] 10 is a circuit diagram illustrating a first circuit configuration of an IO board 45. FIG. [Figure 6] 10 is a circuit diagram illustrating a second circuit configuration of the IO board 45. FIG. [Figure 7] FIG. 10 is a diagram for explaining the effect of the first embodiment. [Figure 8] FIG. 2 is a circuit diagram illustrating the configuration of an IO board 45. [Figure 9] 10 is a circuit diagram illustrating a first circuit configuration of an IO board 45. FIG. [Figure 10] 10 is a circuit diagram illustrating a second circuit configuration of the IO board 45. FIG. [Figure 11] FIG. 2 is a circuit diagram illustrating the configuration of an IO board 45. [Figure 12] 10 is a diagram for explaining the operation of the IO board 45. FIG. [Figure 13]10 is a diagram for explaining the operation of the IO board 45. FIG. [Figure 14] FIG. 10 is a schematic block diagram illustrating the configuration of an IO board 45. DETAILED DESCRIPTION OF THE INVENTION

[0010] Embodiment 1 Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0011] <Injection molding machine> An injection molding machine 100 according to this embodiment will be described below with reference to Fig. 1. Fig. 1 is an external view of the injection molding machine 100. The injection molding machine 100 includes a clamping unit 10 that clamps a mold, an injection unit 20 that melts and injects an injection material, a display unit 30, and a control unit 40.

[0012] The injection molding machine 100 is placed on an XY plane. The direction perpendicular to the XY plane is the Z-axis direction. The positive direction of the Z-axis in Fig. 1 may be referred to as the upper surface side or upward, and the negative direction as the lower surface side or downward.

[0013] <Mold clamping device> The mold clamping device 10 includes a bed 11, a fixed platen 12, a mold clamping housing 13, a movable platen 14, tie bars 15, a mold clamping mechanism 16, molds 17 and 18, and a ball screw 51. The bed 11 supports the components of the mold clamping device 10, such as the fixed platen 12, the mold clamping housing 13, and the movable platen 14. The fixed platen 12 is fixed to the bed 11. The mold clamping housing 13 is configured to be slidable in the X-axis direction on the bed 11. Similarly, the movable platen 14 is configured to be slidable in the X-axis direction on the bed 11.

[0014] The tie bars 15 are disposed between the fixed platen 12 and the clamping housing 13, and connect the fixed platen 12 and the clamping housing 13. The tie bars 15 include a plurality of bars. The injection molding machine 100 shown in FIG. 1 is equipped with the tie bars 15 including four bars. Note that the tie bars 15 may include five or more bars.

[0015] The movable platen 14 is configured to be slidable in the X-axis direction between the fixed platen 12 and the mold clamping housing 13. The mold clamping mechanism 16 is provided between the mold clamping housing 13 and the movable platen 14. The mold clamping housing 13 in the first embodiment is configured to include a toggle mechanism. Note that the mold clamping mechanism 16 may be configured to include a direct pressure type mold clamping mechanism. The direct pressure type mold clamping mechanism means a mold clamping cylinder.

[0016] The molds 17 and 18 are provided between the fixed platen 12 and the movable platen 14. The molds 17 and 18 are configured to be opened and closed by the mold clamping mechanism 16. The ball screw 51 converts the rotational motion of the motor 50 into linear motion, thereby opening and closing the mold clamping mechanism 16.

[0017] <Injection device> The injection device 20 includes a base 21, a heating cylinder 22, a screw 23, a drive mechanism 24, a hopper 25, an injection nozzle 26, and a nozzle touch device 27. The base 21 is disposed on the positive side of the X-axis of the bed 11, and supports the drive mechanism 24 and the like. The screw 23 is disposed inside the heating cylinder 22. The drive mechanism 24 rotates the screw 23 about the X-axis direction as its central axis, and drives the screw 23 itself to slide in the X-axis direction.

[0018] The hopper 25 is provided on the positive side of the Z axis of the heating cylinder 22. The injection nozzle 26 is provided at the end of the heating cylinder 22 on the negative side of the X axis. The nozzle touch device 27 slides the injection device 20 in the X axis direction to bring the injection nozzle 26 into contact with the sprue bushing of the mold 18.

[0019] The base 21 includes therein a control device 40, a servo amplifier 53, a cooling fan 54, and a relay 56. The control device 40 includes a control board 52 equipped with a CPU, a memory, etc. The control device 40 comprehensively controls the injection molding machine 100.

[0020] The servo amplifiers 53 supply three-phase AC power to the corresponding motors. The cooling fans 54 blow or discharge air to prevent the heat-generating components arranged inside the base 21 from overheating. The relays 56 are, for example, thermal relays or current relays for preventing motor overload. The relays 56 may also be used for purposes other than preventing motor overload.

[0021] Display device 30 is provided on the negative side of injection molding machine 100 along the Y axis. Display device 30 includes a display 31 and an input device 32. Input device 32 includes, for example, a plurality of buttons. In one aspect, display device 30 may include a plurality of displays and speakers, etc. Furthermore, display 31 and input device 32 may be integrated into a touch panel. Note that, although an example of a horizontal injection molding machine has been described in FIG. 1, injection molding machine 100 of embodiment 1 is not limited to this and may also be a vertical injection molding machine.

[0022] The injection molding machine 100 is configured to allow the user to connect various externally connected devices 101 depending on the type of molded product. The injection molding machine 100 further includes an input / output board (hereinafter referred to as an IO (Input-Output) board) 45 for connecting the externally connected device 101. The IO board 45 is configured to receive digital signals from the externally connected device 101.

[0023] <Injection molding machine block diagram> 2 is a schematic block diagram of the injection molding machine 100. The control device 40 includes a storage unit 44 and a control board 52. The storage unit 44 may include, for example, a hard disk drive (HDD) or a flash solid state drive (SSD). The control board 52 is equipped with a calculation unit 41, an input interface 42, and an output interface 43. The calculation unit 41 includes a CPU 41a and a memory 41b.

[0024] The memory 41b includes a read-only memory (ROM) and a random access memory (RAM), and stores programs to be executed by the CPU 41a, etc. The CPU 41a loads the programs stored in the ROM into the RAM and executes them.

[0025] The calculation unit 41 may be configured by a dedicated hardware circuit. That is, the calculation unit 41 may be realized by an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), etc. The calculation unit 41 may also be realized by appropriately combining a processor, a memory, an ASIC, an FPGA, etc.

[0026] The calculation unit 41 receives digital signals from the externally connected device 101 connected to the IO board 45 via the input interface 42. The calculation unit 41 sends control commands to the drive mechanism 24 and the display device 30 via the output interface 43. The calculation unit 41 drives the drive mechanism 24 using the detection values ​​of the various sensors. The calculation unit 41 displays the status of the injection molding machine 100 on the display device 30 based on the detection values ​​of the various sensors.

[0027] 3 is a diagram showing an example of an externally connected device 101 and an example of a connection configuration. The externally connected device 101 includes a remover 103 that removes the molded product from the mold after injection molding, and a PLC (Programmable Logic Controller) 102 that connects the remover 103 to the IO board 45 of the injection molding machine.

[0028] The PLC 102 sends a signal to the IO board 45. Upon receiving the signal from the IO board 45, the control device 40 drives the drive mechanism 24 or sends a control command to the display device 30. The control device 40 may also drive drive components (such as an arm or a chuck) of an externally connected machine connected to the output interface 43.

[0029] 4 is a circuit diagram illustrating the configuration of the IO board 45. The IO board 45 corresponds to the above-mentioned input circuit. In the IO board 45, an internal circuit (not shown) is electrically insulated from the input terminals T1 and T2, and signals are transmitted via a photocoupler PC. Note that an insulating element other than a photocoupler may also be used.

[0030] The IO board 45 includes a pair of input terminals T1 and T2, a load 451, and a switching circuit 452. The input terminal T1 is a high-potential input terminal, and the input terminal T2 is a low-potential input terminal. The load 451 includes an internal circuit (not shown), a photocoupler PC, and resistors R1 and R2. The photocoupler PC includes a light-emitting diode LD1 and a phototransistor PT1. The light-emitting diode LD1 is connected in parallel to the resistor R1, and the phototransistor PT1 is connected to the internal circuit. One end of the resistor R2 is connected to the connection node between the cathode terminal of the light-emitting diode LD1 and the resistor R1.

[0031] The circuit configuration of the switching circuit 452 can be switched between a first circuit configuration corresponding to a sink input type in which current is drawn from the load 451 to the input terminal T1, and a second circuit configuration corresponding to a source input type in which current is output from the input terminal T2 to the load 451. The switching circuit 452 is disposed between the load 451 and the input terminals T1 and T2.

[0032] Specifically, the switching circuit 452 includes switches SW1 to SW3. The switches SW1 to SW3 may be configured by, for example, relays. The relays are not limited to mechanical contact relays, and may be contactless relays using semiconductors. The switches SW1 to SW3 may be switches other than relays.

[0033] The switch SW1 switches the connection destination of the high-potential line PL between the one end of the resistor R1 that is not connected to the resistor R2, i.e., the high-potential side of the load 451, and the input terminal T1. The switch SW2 switches the connection destination of the low-potential line NL between the one end of the resistor R2 that is not connected to the resistor R1, i.e., the low-potential side of the load 451, and the input terminal T2. The potential of the low-potential line N is lower than the potential of the high-potential line P. The switch SW3 switches between a state in which the input terminal T1 is connected to the low-potential side of the load 451 and a state in which the input terminal T2 is connected to the high-potential side of the load 451. The switch SW3 may be configured, for example, by a relay having two built-in contacts.

[0034] FIG. 5 is a circuit diagram illustrating a first circuit configuration of the switching circuit 452. Sink input signals are input to input terminals T1 and T2. In the sink input configuration, the collector terminal of an NPN transistor Tr1 is connected to the input terminal T1, and the emitter terminal of the transistor Tr1 is connected to the input terminal T2. The switch SW1 connects the high-potential line PL to the high-potential side of the load 451. The switch SW2 connects the low-potential line NL to the input terminal T2. The switch SW3 connects the input terminal T1 to the low-potential side of the load 451. In this case, as indicated by the dotted arrow, a current flows from the load 451 to the input terminal T1 and is absorbed by the collector of the transistor Tr1.

[0035] FIG. 6 is a circuit diagram illustrating a second circuit configuration of the switching circuit 452. Source input type signals are input to input terminals T1 and T2. In the source input type, the emitter terminal of a PNP transistor Tr2 is connected to the input terminal T1, and the collector terminal of the transistor Tr2 is connected to the input terminal T2. The switch SW1 connects the high potential line PL to the input terminal T1. The switch SW2 connects the negative potential line NL to the negative potential side of the load 451. The switch SW3 connects the input terminal T2 to the high potential side of the load 451. In this case, as indicated by the dotted arrow, the collector of the transistor Tr2 sources current, and current flows from the input terminal T2 to the load 451.

[0036] 2 again, the states of the switches SW1 to SW3 may be switched in response to a user input to the input device 32. For example, the user may set whether the input format for each pair of input terminals is a sink input format or a source input format in accordance with a setting screen displayed on the display 31. The calculation unit 41 performs control to change the states of the switches SW1 to SW3 based on the user input.

[0037] Note that the input formats of some of the input terminals mounted on the IO board 45 may be set by a general user. The calculation unit 41 may display on the display 31 a dedicated screen for developers or service personnel to set the above-mentioned some of the input terminals.

[0038] Next, a description will be given of the effects achieved by the injection molding machine 100 and the IO board 45 according to embodiment 1. The injection molding machine 100 and the IO board 45 according to embodiment 1 can accommodate both sink input type signals and source input type signals while preventing an increase in the number of input terminals.

[0039] By providing four input terminals for each signal and shorting the input terminals to which no signals are input, it is possible to support both sink and source input formats, but this approach poses the problem of increasing the number of input terminals. Because the injection molding machine 100 performs complex operations, many monitoring signals are input to the injection molding machine. The injection molding machine 100 also needs to handle signals added as user options. Furthermore, because the injection molding machine 100 interfaces with multiple devices, signals from multiple devices are input to the injection molding machine 100. For these reasons, the injection molding machine 100 handles a very large number of signals. Therefore, providing four input terminals for each signal would result in an extremely large area for arranging the input terminals.

[0040] The upper diagram in FIG. 7 illustrates the configuration of the input terminals of the IO board 45 to which ten types of signals are input. The letter A represents the spacing between the input terminals T1 and T2. The lower diagram in FIG. 7 illustrates the configuration of an IO board that includes, for each of the ten types of signals, a pair of input terminals T11-T12 dedicated to sink input format and a pair of input terminals T21-T22 dedicated to source input format. The letter B represents the spacing between the input terminals T11, the spacing between the input terminals T12, the spacing between the input terminals T21, and the spacing between the input terminals T22. In this example, the size of the area in which the input terminals are arranged can be reduced by approximately 37%. This allows for a reduction in the size of the IO board 45 and the control panel on which the IO board 45 is mounted.

[0041] Embodiment 2 Fig. 8 is a circuit diagram showing the configuration of the IO board 45 according to the second embodiment. Comparing Fig. 4 with Fig. 8, the switching circuit 452 of the IO board 45 according to the second embodiment includes component mounting locations 71 to 76 instead of the switches SW1 to SW3.

[0042] The high-potential line PL is connected to input terminal T1 via component mounting location 71, and is connected to the high-potential side of load 451 via component mounting location 72. The low-potential line NL is connected to input terminal T2 via component mounting location 73, and is connected to the low-potential side of load 451 via component mounting location 74. Input terminal T1 is connected to the low-potential side of load 451 via component mounting location 75, and input terminal T2 is connected to the high-potential side of load 451 via component mounting location 76.

[0043] Fig. 9 is a circuit diagram illustrating a first circuit configuration. Electronic components such as wires and resistors are placed at component mounting locations 72, 73, and 75, and no electronic components are placed at component mounting locations 71, 74, and 76. Fig. 10 is a circuit diagram illustrating a second circuit configuration. Electronic components are placed at component mounting locations 71, 74, and 76, and no electronic components are placed at component mounting locations 72, 73, and 75.

[0044] The second embodiment can also achieve the same effects as the first embodiment.

[0045] Embodiment 3 FIG. 11 is a circuit diagram showing the configuration of the IO board 45 according to the third embodiment. Comparing FIG. 4 with FIG. 11, the IO board 45 further includes a cutoff unit 61. The cutoff unit 61 cuts off the short-circuit current flowing through the switching circuit 452. The cutoff unit 61 may be provided in a path between the high potential line PL and the switch SW1. The cutoff unit 61 is, for example, a fuse. The cutoff unit 61 may be provided in the switches SW1 to SW3. For example, the switches SW1 to SW3 may be thermal relays or thermal FETs (Field Effect Transistors).

[0046] 12 and 13, the operation of the IO board 45 according to the third embodiment will be described. Referring to FIG. 12, sink input type signals are input to the input terminals T1 and T2. In a first circuit configuration corresponding to the sink input type, the high potential line PL is connected to the high potential side of the load 451. Here, if the switch SW1 erroneously connects the high potential line PL to the input terminal T1, there is a risk that a short-circuit current will flow through the erroneous current path indicated by the dotted arrow, but the cutoff unit 61 can cut off the short-circuit current.

[0047] 13, source input type signals are input to input terminals T1 and T2. In a second circuit configuration corresponding to the source input type, switch SW3 connects input terminal T2 to the high potential side of load 451. If switch SW3 erroneously connects input terminal T1 to the low potential side of load 451, there is a risk that a short-circuit current will flow through the erroneous current path indicated by the dotted arrow, but cutoff unit 61 can cut off the short-circuit current.

[0048] The third embodiment can prevent a short-circuit current from flowing when the circuit configuration of the switching circuit 452 is not switched to the correct circuit configuration.

[0049] Embodiment 4 14 is a block diagram illustrating the configuration of the IO board 45 according to the fourth embodiment. Comparing FIG. 4 with FIG. 14, the IO board 45 according to the fourth embodiment includes light emitting elements 62 to 63 and a control circuit 64.

[0050] The light-emitting element 62 emits light in a first emission color (e.g., blue). The light-emitting element 63 emits light in a second emission color (e.g., red) different from the first emission color. The light-emitting elements 62 and 63 may be mounted on a single light source. The control circuit 64 turns on the light-emitting element 62 when the circuit configuration of the switching circuit 452 is a first circuit configuration corresponding to the sink input format. The control circuit 64 turns on the light-emitting element 63 when the circuit configuration of the switching circuit 452 is a second circuit configuration corresponding to the source input format.

[0051] According to the fourth embodiment, the user can know that an abnormality has occurred in the switching circuit 452 from the lighting states of the light-emitting elements 62 and 63. For example, when the light-emitting element 62 is not lit and the light-emitting element 63 is not lit, the user can determine that an abnormality has occurred in the switching circuit 452.

[0052] Variations Referring again to FIG. 2, a modified example of the fourth embodiment will be described. The calculation unit 41 of the injection molding machine 100 according to the modified example collects information indicating the states of the switches SW1 to SW3 on the IO board 45. The state of each switch may be an open / closed state or a path switching state. The calculation unit 41 may, for example, collect information indicating the open / closed state of one or more auxiliary contacts included in each of the switches SW1 to SW3, which are mechanical relays. The calculation unit 41 may also collect information regarding the potential of one end of each of the switches SW1 to SW3, which are semiconductor relays.

[0053] Based on the collected information, the calculation unit 41 diagnoses an abnormality in the switching circuit 452. For example, when the circuit configuration of the switching circuit 452 based on the collected information does not correspond to either the first circuit configuration or the second circuit configuration, the calculation unit 41 may diagnose that the state of the switching circuit 452 is abnormal.

[0054] The calculation unit 41 may take into consideration the input format to the input terminals T1 to T2 to diagnose an abnormality in the switching circuit 452. When the sink input format is set as the input format to the input terminals T1 to T2 and the circuit configuration of the switching circuit 452 does not correspond to the first circuit configuration, the calculation unit 41 may diagnose that the state of the switching circuit 452 is abnormal. When the source input format is set and the circuit configuration of the switching circuit 452 does not correspond to the second circuit configuration, the calculation unit 41 may diagnose that the state of the switching circuit 452 is abnormal.

[0055] The calculation unit 41 according to the modification of the fourth embodiment can diagnose abnormalities in the switching circuit 452. If an abnormality occurs, the calculation unit 41 may output an alarm or stop the operation of the injection molding machine 100. The calculation unit 41 may be provided on the IO board 45.

[0056] The present disclosure is not limited to the above-described embodiment, and may be modified as appropriate without departing from the spirit of the present disclosure. For example, the IO board 45 may be mounted on a device other than the injection molding machine 100. [Explanation of symbols]

[0057] 10 mold clamping unit, 11 bed, 12 fixed platen, 13 mold clamping housing, 14 movable platen, 15 tie bar, 16 mold clamping mechanism, 17, 18 mold, 20 injection unit, 21 base, 22 heating cylinder, 23 screw, 24 drive mechanism, 25 hopper, 26 injection nozzle, 27 nozzle touch device, 30 display device, 31 display, 32 input device, 40 control device, 41 calculation unit, 41a CPU, 41b memory, 42 input interface, 43 output interface, 44 memory unit, 45 input / output board, 50 motor, 51 ball screw, 52 control board, 53 servo amplifier, 54 cooling fan, 56 relay, 100 injection molding machine, 101 external connection machine, 103 take-out machine, T1 to T2 terminals, SW1 to SW3 switches, PL high potential line, NL Low potential line, R1 to R2 resistors, PC photocoupler, LD1 light emitting diode, PT1 phototransistor, Tr1 to Tr2 transistors, 451 load, 452 switching circuit, 61 cutoff section, 62 to 63 light emitting element, 64 control circuit, 71 to 76 component mounting locations,

Claims

1. a pair of input terminals; Switching circuit and Equipped with The circuit configuration of the switching circuit is switched between a first circuit configuration corresponding to a sink input type in which a current is drawn from a load to one of the pair of input terminals, and a second circuit configuration corresponding to a source input type in which a current is output from the other of the pair of input terminals to the load. Input circuit.

2. the switching circuit includes a switch; By changing the state of the switch, the circuit configuration of the switching circuit is switched.

2. The input circuit of claim 1.

3. The switching circuit includes a first component mounting location where an electronic component is placed when the circuit configuration of the switching circuit is set to the first circuit configuration, and a second component mounting location where the electronic component is placed when the circuit configuration of the switching circuit is set to the second circuit configuration.

2. The input circuit of claim 1.

4. A cut-off unit that cuts off the short-circuit current flowing through the switching circuit 2. The input circuit of claim 1.

5. A calculation unit is provided to collect information indicating the state of the switch and diagnose an abnormality in the switching circuit.

3. The input circuit of claim 2.

6. a calculation unit that controls changing the state of the switch based on a user input for setting the circuit configuration of the switching circuit; 3. The input circuit of claim 2.

7. A control circuit is provided to cause the light emitting element to emit light based on the circuit configuration of the switching circuit.

3. The input circuit of claim 2.

8. An injection molding machine having an input circuit, The input circuit a pair of input terminals; Switching circuit and Equipped with The circuit configuration of the switching circuit is switched between a first circuit configuration corresponding to a sink input type in which a current is drawn from a load to one of the pair of input terminals, and a second circuit configuration corresponding to a source input type in which a current is output from the other of the pair of input terminals to the load. Injection molding machine.

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