JPS61293783A - Driving mechanism of multi-joint type manipulator for nuclear reactor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Technical field to which the invention pertains]

The present invention relates to a drive mechanism for an articulated manipulator for a nuclear reactor, which is intended for use as a manipulator that is inserted into the reactor through a standpipe installed at the top of the reactor to perform various inspections, simple repairs, etc. inside the reactor.

[Prior art and its problems]

As mentioned above, a manipulator is inserted into the reactor, and a TV camera is installed on the work unit attached to the end of the arm to visually inspect the inside of the reactor using a monitor, or a workpiece such as a grab mechanism is installed. A multi-joint manipulator that can be used to perform various operations inside a furnace is known. Here, the outline of the multi-joint type manipulator used in the nuclear reactor will be explained with reference to FIG. 3. In the figure, 1 is the pressure vessel of the nuclear reactor that houses the core, and 2
．． 3 is a primary and secondary shield, 4 is a stand pipe that penetrates the secondary shield 2 and is installed on the upper surface of the pressure vessel 1, 5 is a charge plate inside the reactor, and 6 is connected to the reactor core through the stand pipe 4. The loaded fuel control rod 7 is an articulated manipulator that is the subject of this invention. This manipulator 7 connects the stand pipe 4 from the floor of the secondary shield 3.
It is loaded into the furnace through a guide tube 8 installed inside the furnace, and is remotely controlled via a drive device 9 in response to commands given to an operation panel (not shown). As is well known, the manipulator 7 constitutes an articulated manipulator arm with multiple stages of links interconnected in series through joints, and a servo motor built into the casing of each link serves as an actuator. The work unit 10, such as a TV camera attached to the arm's end link, is pulled in the furnace by rotating the end link and rotating the joints between each link through the joint drive mechanism. It is rotated and moved to perform various inspection 1 operations. The illustration shows a state in which the situation inside the high temperature gas duct la of the pressure vessel 1 is being monitored with a TV camera. By the way, this type of articulated manipulator is widely used not only for the above-mentioned nuclear reactors but also as the arm of industrial robots, and it is possible that the manipulators installed in these industrial robots may malfunction during operation. If this happens, the robot can be shut down and maintenance personnel can approach the machine and perform the necessary repair actions. However, with the articulated manipulator shown in Figure 3, which is inserted into the nuclear reactor and used, even if a failure occurs in the drive system during use, maintenance personnel cannot access the manipulator. can be,
To repair a faulty part, the Mayupierator must be pulled out of the reactor through a standpipe.For this reason, manipulators for nuclear reactors use their own blades to remove the arm when a fault occurs, regardless of the arm posture during use. It is necessary to drive and correct the attitude so that it can be pulled out of the reactor and recovered through the standpipe of the reactor.

[Purpose of the invention]

This invention was developed in consideration of the above points, and even if a failure occurs in the drive system of the manipulator while the manipulator is inserted into a nuclear reactor and used, the manipulator arm can be automatically removed by its own blade. The object of the present invention is to provide a highly reliable drive mechanism for a multi-jointed manipulator for use in a nuclear reactor, in which the manipulator can be corrected to a recoverable posture, pulled out of the reactor through a standpipe, and recovered.

[Additional points to the invention]

In order to achieve the above object, the present invention interposes a non-excitation operated electromagnetic clutch and a non-excitation operated electromagnetic brake in series between the output shaft of a servo motor, which is an actuator of a drive mechanism, and a reduction mechanism. It is composed of With this configuration, if the servo motor becomes inoperable due to seizure, galling, etc. that causes the motor to lock while the manipulator is inserted into the nuclear reactor, commands from the outside cannot be issued. By releasing the electromagnetic clutch and disconnecting the servo motor from the drive system, and further loosening the electromagnetic brake, the driven link can move freely and the manipulator can be pulled out of the furnace through the stand pipe and recovered. In addition, by setting the maximum output torque of the servo motor to be greater than the braking torque of the brake, even if a failure occurs in the electromagnetic brake or its power supply system and it becomes impossible to release the brake, By increasing the output torque of the servo motor beyond the braking torque and forcibly driving the driven link to rotate, it becomes possible to correct the link's posture, and as before, the manipulator is pulled out of the reactor through the stand pipe. It can be recovered.

[Embodiments of the invention]

1 and 2 show an embodiment of the invention, and the same parts corresponding to FIG. 3 are given the same reference numerals. Here, FIG. 1 shows the reference numeral 78 that holds the work unit 10 among the multi-stage links constituting the manipulator arm.
This figure shows a joint drive mechanism for the joint between the tip link indicated by 7b and the next link indicated by the reference numeral 7b. That is, the links la and 1b are hinged together through a pin serving as a rotating shaft between the hinges lla extending from each link casing 11, and the driven side tip link 7a is connected to the drive side link 7b within the casing 11. A rotation drive mechanism 12 built into the hinge drive mechanism 12 is transmission-coupled so as to rotate the hinge in the direction indicated by the arrow around the axis of rotation of the hinge. Here, the above-mentioned swing drive mechanism 12 uses a servo motor 13 as an actuator, and an electromagnetic non-excitation type is connected between this output shaft and a reducer of Harmonic Drive (a product name of Harmonic Drive Systems Inc.) indicated by reference numeral 14. A clutch 15 and a non-excitation type electromagnetic brake 16 are interposed in series, and a bevel gear 17 is connected to the output shaft of the reducer 14, and a bevel gear 18 is integrated with the hinge on the link 7a side. It is configured by directly connecting the Among the above-mentioned parts, the electromagnetic clutch 15 has a built-in solenoid coil, and when it is not energized, the clutch plates are connected to transmit power from the servo motor, and when the coil is energized, the clutch plates are separated by electromagnetic force. It is a non-excitation operated electromagnetic clutch that operates to cant power transmission. On the other hand, the electromagnetic brake 16 is released when the built-in solenoid coil is energized, and is activated in other non-excited states (it is a non-excitation type brake, and when the link 1a is driven to swing, the braking is applied by excitation. is released to transmit the power of the servo motor 13 to the driven link, and when the servo motor 13 is stopped, the excitation is released and braking is applied to stop and hold the driven link at that position.The braking torque of this electromagnetic brake 16 is set to a value larger than the normal drive torque of the servo motor 13 and smaller than the maximum torque of the servo motor.Next, the rotation drive operation of the joint between the links with the above configuration, and the failure of the drive system during use, are set. We will explain the steps to take when this occurs. First, in order to rotate the interlink joint in a normal state, start the servo motor 13 while releasing the electromagnetic brake 16, and the electromagnetic clutch 15 .Electromagnetic brake 16. The gear 18 is rotated by the rotational driving force transmitted to the bevel gear 17 via the reducer 14, so that the tip link la moves in the direction of arrow A around the axis of rotation of the hinge.
It is driven to rotate in the direction. In this case, the turning angle of the tip link 7a is detected by a potentiometer 19 directly connected to the hinge rotation axis between the link 7a and the link 7b. Further, when the link 7a is turned to a desired angle, the servo motor 13 is stopped, and at the same time the electromagnetic brake 16
By applying the brake at , the link 7a comes to be stopped and held at that position. On the other hand, while the manipulator is being used in a nuclear reactor with its arm bent as shown in Figure 3, the servo motor 1
If a malfunction such as seizure or galling occurs in the servo motor 13 and the servo motor 13 becomes inoperable, first energize the electromagnetic clutch 15 with an external command to disengage the clutch.
In this state, the electromagnetic brake 1 is disconnected from the drive system.
By applying excitation to 6 and loosening the brake, the tip link 7
A can move freely without restraint. If the link 7b is pivoted to the vertical position along the stand pipe 4 shown in FIG. The link posture is automatically corrected to a vertical posture by following the alignment so that the manipulator can be pulled out of the furnace through the stand pipe and recovered. In this case, by using the complete harmonic drive reducer as the reducer 14, the reduction gear can be rotated freely even from the driven side without self-locking occurring as in the case of a worm gear type reducer. It's convenient. Further, the work unit 10 supported by the tip link 7a is disconnected from the tip link 7a and separated before the manipulator 7 is pulled out of the furnace, and is left on the charge plate 5 inside the furnace. In addition to the above-mentioned failure of the servo motor 13, in the unlikely event that a failure occurs in the electromagnetic brake 16 or its power supply system while the manipulator is in use, and the braking is not released even if excitation is applied, By increasing the output torque of the servo motor 13 and driving it with a torque greater than the braking torque of the electromagnetic brake 16, it becomes possible to overcome the braking force of the brake 16 and swing the tip link 7a to a desired position.

【Effect of the invention】

As described above, according to the present invention, a non-excitation-operated electromagnetic clutch and a non-excitation-operated electromagnetic clutch are connected between the output shaft of the servo motor, which is the actuator, and the reduction mechanism for the joint-related mechanism between the links. By installing an electromagnetic brake in series, even if a servo motor malfunctions while the manipulator is inserted into the reactor, the clutch and brake can be released. By freeing the movement between the links, the manipulator can be pulled out of the reactor and recovered through the stand pipe, thereby providing an articulated manipulator that is highly reliable in handling for use in nuclear reactors. Can be done.

[Brief explanation of drawings]

FIGS. 1 and 2 are a perspective view and a side view, respectively, showing the drive mechanism of the joint between links of an articulated manipulator for a nuclear reactor according to an embodiment of the present invention, and FIG. 3 is a state in which it is loaded into a nuclear reactor. In Figure 0, which is a schematic configuration diagram of the entire articulated Mayupierator, 1+Reactor pressure vessel, 4 Nistand pipe, 7: Manipulator, 7a, 7b: Links of each stage, 10: Work unit, 11: Link casing , 12: joint attachment mechanism, 13: servo motor, 14: speed reducer, 15: non-excitation operated electromagnetic clutch, ill non-excitation operated electromagnetic brake, 17.18: gear, A: swing drive direction of driven link. Figure 2

Claims (1)

[Claims] 1) An articulated manipulator that is used by being inserted into the reactor through a standpipe installed at the top of the reactor, and the manipulator arm is composed of multiple stages of links connected in series with each other. and the rotational drive of the joints between each link is performed via a drive mechanism built into the link casing on the drive side, in which the output shaft of the servo motor that is the actuator of the drive mechanism and the reduction mechanism A drive mechanism for an articulated manipulator for a nuclear reactor, comprising a non-excitation operated electromagnetic clutch and a non-excitation operated electromagnetic brake interposed in series. 2) In the drive mechanism according to claim 1, the braking torque of the electromagnetic brake is set to a value larger than the normal driving torque of the servo motor and smaller than the maximum output torque of the servo motor. Features a drive mechanism for an articulated manipulator for nuclear reactors.