WO2023275966A1

WO2023275966A1 - Power supply device

Info

Publication number: WO2023275966A1
Application number: PCT/JP2021/024473
Authority: WO
Inventors: 佑典鈴木
Original assignee: 株式会社Fuji
Priority date: 2021-06-29
Filing date: 2021-06-29
Publication date: 2023-01-05
Also published as: JPWO2023275966A1

Abstract

A power control device 100 comprises: a power supply board 110 for supplying power to motors 41m-44m for operating a robot arm; one or more expanded capacitor boards 120 connected in parallel with a power line DCLINK of the power supply board 110 and increasing the capacitance of the power line DCLINK; electrolytic capacitors C3-C5 provided to the expanded capacitor boards 120 and used for increasing the capacitance of the power line DCLINK; and an inrush current suppression resistor R3 provided to the expanded capacitor boards 120 and preventing a significant inrush current from flowing in the electrolytic capacitors C3-C5 from the power line DCLINK when the expanded capacitor boards 120 are connected to the power line DCLINK.

Description

power supply

The present disclosure relates to a power supply device that supplies power to a motor that operates a robot arm.

Patent Literature 1 describes a power supply control device capable of suppressing the generation of inrush current when a power switch is turned on to a bypass capacitor connected in parallel to a load to which a DC voltage is supplied from a DC power supply via a power switch. ing.

Japanese Patent No. 6467902

By the way, in robots such as articulated robots and SCARA robots, which are equipped with an amplifier board that controls the variation of the voltage applied to the motors that operate the robot arms, there are situations where instantaneous movements are required. In order to achieve that instantaneous operation, it is sometimes desirable to increase the capacitance by connecting a large-capacity electrolytic capacitor in parallel with the power supply line, but due to size restrictions on the amplifier board and height restrictions on the mounting location, etc. , it may not be possible to install enough electrolytic capacitors to provide the required capacitance.

However, Patent Document 1 does not describe increasing the capacitance, so even if the power control device described in Patent Document 1 is used, the above problem cannot be solved.

An object of the present disclosure is to provide a power supply device that can easily increase the capacitance of a power supply line when desired.

To achieve the above object, the power supply device of the present disclosure includes a power supply board that supplies power to a motor that operates a robot arm, and a power supply line connected in parallel to the power supply board to increase the capacitance of the power supply line. one or more extended capacitance substrates; a capacitor provided on the extended capacitance substrate for increasing the capacitance of the power supply line; an inrush current suppressing mechanism for suppressing an excessive inrush current from flowing into the capacitor.

According to the present disclosure, when it is desired to increase the capacitance of the power supply line, it is possible to easily increase the capacitance.

It is a perspective view which shows the outline of a structure of a component mounter. FIG. 3 is a block diagram showing the electrical connection relationship of the control device; 3 is an electric circuit diagram showing the circuit configuration of the power supply device; FIG. FIG. 4 is an electric circuit diagram used for simulating the action of an inrush current prevention resistor; 5 is a diagram showing a simulation result of the electric circuit of FIG. 4; FIG. FIG. 5 is an electric circuit diagram in which an extension capacity is added to the electric circuit of FIG. 4; FIG. 7 is a diagram showing a simulation result of the electric circuit of FIG. 6; It is a figure which shows the connection aspect which connects an expansion capacity|capacitance to a motive power supply line.

Hereinafter, embodiments of the present disclosure will be described in detail based on the drawings. FIG. 1 shows an outline of the configuration of the mounter 10, and FIG. 2 shows the electrical connections of the control device 60. As shown in FIG. Note that the vertical direction in FIG. 1 is the Z-axis direction.

The component mounter 10 of this embodiment includes a vertical articulated robot 40, a Z-axis movement device 50, a nozzle 53, and a control device 60 (see FIG. 2).

The vertical articulated robot 40 has four robot movable parts (shoulder 42, lower arm 43, upper arm 44 and wrist 45). The four robot movable parts are connected on a cylindrical base part 41 . Specifically, the shoulder 42 is connected to the upper surface of the base portion 41 via a first joint 41j so as to be rotatable around the vertical shaft 41a. A lower end of a lower arm 43 is connected to the shoulder 42 via a second joint 42j so as to be rotatable around a horizontal shaft 42a. The base end of the upper arm 44 is connected to the upper end of the lower arm 43 via a third joint 43j so as to be rotatable around the horizontal shaft 43a. A wrist 45 is connected to the distal end of the upper arm 44 via a fourth joint 44j so as to be rotatable around a shaft 44a extending in a direction perpendicular to the longitudinal direction of the upper arm 44. As shown in FIG. A Z-axis movement device 50 is connected to the wrist 45 so as to be rotatable together with the wrist 45 around an axis 44a. The first joint 41j contains a first motor 41m that drives the shoulder 41 to rotate, and the second joint 42j contains a second motor 42m that drives the lower arm 43 to rotate. The third joint 43j contains a third motor 43m that drives the upper arm 44 to rotate, and the fourth joint 44j contains a fourth motor 44m that drives the wrist 45 to rotate. The first to fourth motors 41m to 44m are provided with first to fourth encoders 41e to 44e (see FIG. 2), respectively. In this embodiment, a servomotor is used as the motor, and a rotary encoder is used as the encoder.

The Z-axis movement device 50 includes a device body 51 and a Z-axis slider 52 . The device main body 51 is a substantially rectangular parallelepiped member here, and is fixed to the wrist 45 . Therefore, the device main body 51 is rotatable around the shaft 44a. The Z-axis slider 52 is attached to the front surface of the device main body 51 so as to be slidable along the longitudinal direction of the device main body 51 . This Z-axis slider 52 is driven by a Z-axis driving device 54 (for example, a linear motor or a ball screw mechanism) attached to the device main body 51 .

The nozzle 53 is provided on the bottom surface of the suction head 55 . The nozzle 53 sucks a component or releases the sucked component by adjusting the pressure at the tip of the nozzle. The nozzle 53 is detachably and axially rotatably attached to the suction head 55 . The suction head 55 is fixed to the Z-axis slider 52 . Therefore, the nozzle 53 slides together with the suction head 55 and the Z-axis slider 52 .

The control device 60 is a device that controls the motion of the vertical articulated robot 40 and the motion of the Z-axis movement device 50 . The control device 60 includes a CPU 61, a ROM 62, an HDD 63, and a RAM 64, as shown in FIG. Connected to the CPU 61 are first to fourth drive circuits 41d to 44d, first to fourth position detection circuits 41p to 44p, a Z-axis drive circuit 54d, a Z-axis position detection circuit 54p, an input device 70, and an output device 72. ing. The first to fourth drive circuits 41d to 44d and the Z-axis drive circuit 54d are provided corresponding to the first to fourth motors 41m to 44m and the Z-axis drive device 54, respectively. The first to fourth drive circuits 41d to 44d and the Z-axis drive circuit 54d output electrical signals based on command signals from the CPU 61 to the corresponding first to fourth motors 41m to 44m and the Z-axis drive device 54. do. The first to fourth position detection circuits 41p to 44p are for detecting the positions of the respective robot movable parts, and are provided corresponding to the first to fourth encoders 41e to 44e, respectively. The Z-axis position detection circuit 54p is for detecting the Z-axis position of the nozzle 53, and is provided corresponding to the Z-axis encoder 54e. The first to fourth position detection circuits 41p to 44p detect the angular positions of the first to fourth motors 41m to 44m based on the detection signals input from the corresponding first to fourth encoders 41e to 44e. Output to the CPU 61 . The Z-axis position detection circuit 54p detects the Z-axis position of the nozzle 53 based on the detection signal input from the Z-axis encoder 54e, and outputs it to CPU61. The input device 70 is a keyboard or a mouse for operator's input operation. The output device 72 is a display that displays various data as visual information such as images.

FIG. 3 shows an outline of the electric circuit of the power control device 100. FIG. The power supply control device 100 mainly includes an AC power supply (sometimes abbreviated as “power supply”) V, a power supply board 110 and an expansion capacity board 120 . The power supply board 110 supplies the motor drive circuit 112 and the like with the power supply DCLINK based on the power supply V. As shown in FIG. The expansion capacity board 120 expands the capacitance of the power supply line DCLINK of the power supply board 110 .

The power supply board 110 has a switch S1 that functions as a safety breaker that turns on/off the supply of the power supply V to the power supply board 110 via the full-wave rectifier circuit 111 . The input terminal of the full-wave rectifier circuit 111 is connected to the output terminal of the switch S1. A full-wave rectifier circuit 111 converts the AC voltage of the power supply V into a DC voltage. One end of an inrush current suppression resistor R1 is connected to the output end of the full-wave rectifier circuit 111, and the other end of the inrush current suppression resistor R1 is connected to one end of each of the positive electrodes of the electrolytic capacitors C1 and C2. The other negative ends of the electrolytic capacitors C1 and C2 are grounded. A switch S2 is connected in parallel with the inrush current suppression resistor R1. Furthermore, the input end of the motor drive circuit 112 is connected to one end on the positive electrode side of each of the electrolytic capacitors C1 and C2. The motor drive circuit 112 includes the first to fourth drive circuits 41d to 44d and the Z-axis drive circuit 54d. A motor 200 is connected to the output end of the motor drive circuit 112 . The motor 200 includes the first to fourth motors 41m to 44m and the Z-axis driving device . In this way, the power supply board 110 is mounted with electronic components from the switch S1 to the motor drive circuit 112. As shown in FIG.

When the switch S1 is turned on, the switch S2 directs the direct current (also abbreviated as "current") supplied from the power supply V through the full-wave rectifier circuit 111 to the electrolytic capacitor via the inrush current suppression resistor R1. The switch S2 is turned off and on to switch whether to supply the current to the capacitors C1 and C2 or bypass the inrush current suppression resistor R1 and directly supply the current to the electrolytic capacitors C1 and C2. The switch S2 is, for example, a relay that automatically switches from off to on when the voltage value of the power supply line DCLINK rises to a predetermined voltage value (<the output voltage value from the full-wave rectifier circuit 111) or higher. ing. The predetermined voltage value, that is, the switching threshold can be set to any value by setting. At the time when the switch S1 is switched from off to on and the supply of current from the power supply V through the full-wave rectifier circuit 111 to the power supply board 110 is started, no charge is accumulated in the electrolytic capacitors C1 and C2. S2 is in an off state. After that, electric charges accumulate in the electrolytic capacitors C1 and C2 as time passes, and when the voltage value of the power supply line DCLINK becomes equal to or higher than the switching threshold, the switch S2 is automatically switched from off to on. As a result, the current supplied from the full-wave rectifier circuit 111 bypasses the inrush current suppression resistor R1 and directly flows into the electrolytic capacitors C1 and C2 via the switch S2. After that, the electrolytic capacitors C 1 and C 2 are fully charged, and the voltage value of the power supply line DCLINK rises to the output voltage value from the full-wave rectifier circuit 111 .

Thus, in the initial stage when the electrolytic capacitors C1 and C2 are not charged, the current from the full-wave rectifier circuit 111 is caused to flow through the electrolytic capacitors C1 and C2 via the inrush current suppression resistor R1. , to limit the current that suddenly flows through the electrolytic capacitors C1 and C2, ie, an excessive inrush current, by the inrush current suppressing resistor R1. If an excessive inrush current occurs, the copper foil pattern of the substrate may be burnt out or the electronic parts may be damaged. However, if the current from the full-wave rectifier circuit 111 is constantly flowing through the inrush current suppression resistor R1, a voltage drop in the power supply line DCLINK and unnecessary heat generation will occur. In other words, when the voltage value of the power supply line DCLINK rises above a predetermined voltage value, the switch S2 is switched from off to on to bypass the inrush current suppression resistor R1. Note that the predetermined voltage value varies depending on the output voltage value from the full-wave rectifier circuit 111, electronic components used, etc., and cannot be determined universally. A lower voltage value is determined empirically or by experiment each time.

Also, the expansion capacity board 120 is connected in parallel to the power supply line DCLINK of the power supply board 110 via the connection line 130 . The expansion capacitor board 120 includes switches S3 and S4, an inrush current suppression resistor R2, and electrolytic capacitors C3 to C5. The connection relationships of the electronic components S4, R2, C3 to C5 provided on the expansion capacity board 120 are substantially the same as the connection relationships of the electronic components S2, R1, C1, C2 provided on the power supply board 110. , the description of which is omitted.

The electrolytic capacitors C3-C5 are capacitors for increasing the capacitance of the power supply line DCLINK. A switch S<b>3 (an example of a “first switching mechanism”) switches ON/OFF of substantial connection of the expansion capacity board 120 to the power supply board 110 . Similarly to the switch S2, the switch S3 is automatically turned on from off when the voltage value of the power supply line DCLINK rises to a predetermined voltage value (<output voltage value from the full-wave rectifier circuit 111) or more. Switching, for example, consists of a relay. However, the switch S3 differs from the switch S2 in that the predetermined voltage value, that is, the switching threshold, may not be the same. The switching threshold of the switch S3 is hereinafter referred to as "first predetermined value". An inrush current suppressing resistor R2 (an example of an "inrush current suppressing mechanism"), like the inrush current suppressing resistor R1, receives an excessive inrush current, that is, the current from the power supply line DCLINK. This is for suppressing an excessive rush current generated by flowing into C5. The switch S4 (an example of the "second switching mechanism") electrolyzes the current supplied from the power supply line DCLINK by turning on the switch S3 through the inrush current suppression resistor R2, similarly to the switch S2. The switch S4 is turned off and on to switch whether to supply the current to the capacitors C3 to C5 or bypass the inrush current suppression resistor R2 and directly supply the current to the electrolytic capacitors C3 to C5. Similarly to the switch S2, the switch S4 is automatically turned on from off when the voltage value of the power supply line DCLINK rises to a predetermined voltage value (<the output voltage value from the full-wave rectifier circuit 111) or higher. Switching, for example, consists of a relay. However, the switch S4 differs from the switches S2 and S3 in that the predetermined voltage value, that is, the switching threshold may not be the same. The switching threshold of the switch S4 is hereinafter referred to as "second predetermined value".

FIG. 4 is an electric circuit diagram used for simulation to show the effect of the inrush current suppression resistor R1 in the power supply board 110. FIG. In FIG. 4, the same electronic parts as those in FIG. 3 are given the same reference numerals. However, the power supply V1 indicates a DC power supply, and in FIG. As can be seen by comparing the electric circuit diagram of FIG. 4 and the electric circuit diagram of FIG. 3, a resistor R11 is added to the electronic components on the power supply board 110 of FIG. The resistor R11 is used for convenience in order to stabilize the output waveform obtained by simulation, and can be ignored in practice. The value displayed near each electronic component indicates the standard of the electronic component.

　Fig. 5 shows the simulation results of the electric circuit in Fig. 4. In the simulation result of FIG. 5, the switch S1 is switched from off to on after 0.5 seconds, and when the voltage value of the power supply line DCLINK reaches 250 V, the switch S2 is switched from off to on. The switching time is approximately 1 second, which is approximately 0.5 seconds after the switch S1 is switched from OFF to ON.

FIG. 5(a) shows the transition of the voltage value G1 of the power supply line DCLINK. In FIG. 5(b), a solid line G2 indicates transition of the current value flowing through the inrush current suppression resistor R1, and a dashed line G3 indicates transition of the current value flowing through the electrolytic capacitor C1. In FIG. 5(c), a solid line G4 indicates transition of the power consumed by the inrush current suppression resistor R1, and a broken line G5 indicates transition of the power supplied to the electrolytic capacitor C1.

From 0.5 seconds to approximately 1 second, the current from the power supply V1 is supplied to the electrolytic capacitor C1 via the inrush current suppression resistor R1, so that the inrush current The peak value of the current flowing through the suppression resistor R1 is approximately 3.0A, and the peak value of the current supplied to the electrolytic capacitor C1 is also approximately 1.5A. The reason why the peak value of the current supplied to the electrolytic capacitor C1 is 1/2 of the peak value of the current flowing through the inrush current suppressing resistor R1 is that the electrolytic capacitors C1 and C2 are connected to the inrush current suppressing resistor R1. This is because the flowing current is equally divided. At this time, assuming that the current from the power supply V1 is supplied directly to the electrolytic capacitor C1 without passing through the inrush current suppression resistor R1, an excessive inrush current of approximately 1400 A instantaneously flows through the electrolytic capacitor C1. . As a result, the electronic components on the power supply board 110 may be damaged or the copper foil pattern may be burned off. By passing through the inrush current suppression resistor R1 in this way, generation of an excessive inrush current is suppressed. On the other hand, from 0.5 seconds to approximately 1 second, the power shown by the solid line G4 in FIG. 5(c) is consumed by the rush current suppression resistor R1. Since the rush current suppressing resistor R1 generates heat due to this power consumption, it is necessary to pay attention to the durability of the current suppressing resistor R1 due to the heat generation.

FIG. 6 shows a simulation for comparing the effect of the inrush current suppression resistor R1 in the power supply board 110 and the effect of the inrush current suppression resistor R2 in the power control device 100 in which the expansion capacity board 120 is connected to the power supply board 110. It is an electric circuit diagram used. In FIG. 6, the same electronic parts as those in FIG. 3 are denoted by the same reference numerals. However, the electronic components on the power supply board 110 in FIG. 6 are given reference numerals obtained by adding "b" to the electronic components on the power supply board 110 in FIG. This is because the electronic components on the power supply board 110 are the electronic components on the power supply board 110 to which the extended capacity board 120 is connected, or the electronic components on the power supply board 110 to which the extended capacity board 120 is not connected. It does so only to distinguish whether it is

FIG. 7 shows the simulation results of the electric circuit of FIG. In the simulation result of FIG. 7, similarly to the simulation result of FIG. S2b is switched from off to on. The switching time is approximately 1 second, which is approximately 0.5 seconds after the switches S1 and S1b are switched from off to on. Moreover, the switch S3 is switched from OFF to ON when the voltage value of the power supply line DCLINK reaches 250V. In FIG. 7, graphs corresponding to the graphs in FIG. 5 are denoted by the same reference numerals.

In FIG. 7(a), the solid line G1 indicates the transition of the voltage value of the power power line DCLINK, and the dashed line G11 indicates the transition of the voltage value of the power power line exDLINK. In FIG. 7(b), a solid line G2 indicates transition of the current value flowing through the inrush current suppression resistor R1b, and a dashed line G3 indicates transition of the current value flowing through the electrolytic capacitor C1b. In FIG. 7(c), a solid line G21 indicates transition of the current value flowing through the inrush current suppression resistor R2, and a broken line G31 indicates transition of the current value flowing through the electrolytic capacitor C3. In FIG. 7(d), a solid line G4 indicates the transition of power consumed by the rush current suppression resistor R1b, and a dashed line G41 indicates the transition of power consumed by the rush current suppression resistor R2. In FIG. 7(e), a solid line G5 indicates transition of the power supplied to the electrolytic capacitor C1b, and a dashed line G51 indicates transition of the power supplied to the electrolytic capacitor C3.

From approximately 1 second to approximately 2.8 seconds, the current from the power supply line DCLINK is supplied to the electrolytic capacitor C3 via the inrush current suppression resistor R2, so that the solid line G21 in FIG. , excessive inrush current is suppressed. Also, the peak value of the power consumed by the inrush current suppression resistor R2 from approximately 1 second to approximately 2.8 seconds is the peak value of the power consumed by the inrush current suppression resistor R1 from 0.5 seconds to approximately 1 second. decreased compared to the peak value. This is because the value of the inrush current limiting resistor R2 is greater than the value of the inrush current limiting resistor R1, so the current passing through the inrush current limiting resistor R2 is more limited. Therefore, the temperature rise due to heat generation of the inrush current suppression resistor R2 is lower than the temperature rise due to heat generation of the inrush current suppression resistor R1. As a result, when R1 and R2 having the same structure are used as the current suppressing resistors, the durability of the inrush current suppressing resistor R2 due to heat generation is improved more than that of the current suppressing resistor R1. If the current passing through the inrush current suppression resistor R2 is further limited in this way, the inrush current supplied to the electrolytic capacitors C3-C5 is further limited, so that the amount of charge per unit time supplied to the electrolytic capacitors C3-C5 is reduced. As a result, as indicated by the dashed line G11 in FIG. 7(a), the voltage value of the power supply line exDLINK gradually rises. That is, the time from when the switch S1 is switched from off to on until the power supply control device 100 enters the standby state is delayed. Therefore, it is desirable to determine the resistance value of the inrush current suppression resistor R2 by comparing the durability of the inrush current suppression resistor R2 and the time required for the power supply control device 100 to enter the standby state.

Also, the second predetermined value of the switch S4 is the voltage value of the power supply line exDLINK when it rises to a value at which there is no danger of excessive inrush current flowing into the electrolytic capacitors C3 to C5. This second predetermined value also cannot be universally determined, like the switching threshold of the switch S2. That is, while the voltage value of the power supply line exDLINK is lower than the second predetermined value, the current from the power supply line DCLINK is supplied to the electrolytic capacitors C3 to C5 via the inrush current suppression resistor R2, and the inrush current is It is limited by the inrush current suppression resistor R2. However, when the voltage value of the power supply line exDLINK becomes equal to or higher than the second predetermined value, the current from the power supply line DCLINK bypasses the inrush current suppression resistor R2 and is directly supplied to the electrolytic capacitors C3 to C5. At this time, the current value of the rush current is determined according to the magnitude of the potential difference between the power supply line DCLINK and the power supply line exDCLINK. This is because it is determined whether or not it becomes excessive.

As described above, in the power supply control device 100 of the present embodiment, it is possible to increase the capacitance of the power supply line DCLINK while suppressing the inrush current simply by connecting the expansion capacitor board 120 to the power supply board 110. In addition, since the expansion capacity board 120 monitors the voltage value of the power supply line DCLINK by itself and automatically switches ON/OFF of the connection to the power supply board 110, there is no need to transmit a switching signal from the outside. As a result, the manufacturing cost of the entire power supply board 110 can be reduced. In addition, when the capacitance increases, the regenerative energy generated on the power supply line DCLINK when the robot 40 decelerates or suddenly stops during operation can be recovered as reusable capacitance instead of being consumed as heat energy. It becomes a device that is friendly to the environment.

　Fig. 8 shows a connection mode for connecting the expansion capacity to the power supply line. FIG. 8A shows a mode of connecting the expansion capacity board 120 when controlling a plurality of motors with one power supply board 110 . FIG. 8(b) shows an example of how the expansion capacity board 120 is connected when a plurality of motors are controlled by a plurality of power supply boards 110a to 110c. Since the connection mode of FIG. 8(a) is the same as the connection mode shown in FIG. 3, further explanation is omitted.

For example, when the power supply boards 110a to 110c shown in FIG. 8B are assembled inside the joints 41j to 43j of the vertical articulated robot 40, the power supply boards 110a to 110c are connected in a daisy chain. However, the farther the control shaft is from the base of the main body, the more the power supply may be delayed or the power supply line DCLINK may sway. If only the hand is operated sharply, or if it is desired to mount an electrolytic capacitor in order to stabilize the power supply line DCLINK by the components of the power supply boards 110a to 110c, but it is not possible to mount it, FIG. 2, the power supply boards 110a to 110c are relayed in such a manner that the expansion capacitor board 120 is connected between the power supply boards 110a to 110c, thereby increasing the capacitance of the power supply line DCLINK. can be stabilized. The interior of the joints 41j to 43j is filled with the power supply boards 110a to 110c and there is often no space. can do.

It should be noted that the present invention is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the present invention. In the above embodiment, an example in which one expansion capacity board 120 is connected to the power supply board 110 has been described. good.

40 Vertical articulated robot 41m to 44m motor 60 control device 100 power control device 110 power supply board 111 full-wave rectifier circuit 112 motor drive circuit 120 expansion capacity board 130 . . Connection line 200 .. Motor V .

Claims

a power supply board that supplies power to a motor that operates the robot arm;
one or more expansion capacitance substrates connected in parallel to a power supply line of the power supply substrate to increase the capacitance of the power supply line;
a capacitor provided on the extension capacitor substrate for increasing the capacitance of the power supply line;
an inrush current suppressing mechanism provided in the extended capacitance substrate for suppressing excessive inrush current from flowing into the capacitor from the power source line when the extended capacitance substrate is connected to the power source line;
power supply with
The power supply device further
a first switching mechanism that switches on connection of the expansion capacitor substrate to the power line when the voltage of the power line rises to a first predetermined value or more,
The power supply device according to claim 1.
The expansion capacity substrate further includes:
After the connection of the expansion capacitor substrate to the power supply line is switched on by the first switching mechanism, when the voltage of the power supply line rises to a second predetermined value or more, the inrush current suppression mechanism including a second switching mechanism that switches off current inflow suppression,
The power supply device according to claim 2.
When there are a plurality of the robot arms, the plurality of the robot arms are operated by the plurality of the motors, and the power supply to the plurality of the motors is performed by the plurality of the power supply boards,
The expansion capacity board is connected between the plurality of power supply boards,
The power supply device according to any one of claims 1 to 3.
The expansion capacity substrate is installed in a hollow portion of one of the plurality of robot arms,
The power supply device according to claim 4.