JP2005103695A - Working robot in reactor, and working method in reactor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a working robot in a reactor, which has simple structure and high operational precision and is not susceptible to failure. <P>SOLUTION: The working robot has movable bodies 5a, 5b driven in an axial direction in an approximately cylindrical main body case 1a, an arm device 3 whose base ends are rotatably connected with the moving bodies 5a, 5b to form a V-link, and a wrist mechanism 7 attached to the tip of the arm device 3 to hold a tool. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an in-furnace working robot and an in-furnace working method that mainly perform work such as inspection and repair in a furnace of a boiling water reactor.

  In order to maintain the soundness of the reactor internals of the nuclear power plant pressure vessel, repairs such as cracks and preventive maintenance measures are required mainly at the weld during the service period. Commonly performed operations include welding operations such as TIG welding and laser welding, polishing operations using a rotating brush, EDM defect removal operations, and peening operations for improving stress. Many of these various repairs and maintenance work are performed in a state where the reactor is filled with water in order to reduce the radiation exposure of workers, and the work environment is underwater. Thus, many underwater specifications remote automatic type in-furnace working robots have been developed (see Patent Document 1 below).

In general, a robot has a servo drive system that constitutes a drive unit. However, an in-furnace work robot is also typically constructed of an AC servo motor or a DC servo motor for both a linear motion mechanism and a rotation mechanism. . That is, in the case of linear motion, the rotation of the motor is generally changed to linear motion with a rack and pinion or a ball screw (see Patent Document 2 below).
Japanese Patent Laid-Open No. 06-308279 JP-A-11-052090

In the in-furnace work, peeling of the oxide film (cladding) from the surface of the in-furnace structure or processing dust may occur. In-furnace working robots that use ball screws have the risk of nuts sticking to the ball screw due to dust, and it is necessary to take measures to prevent dust from entering the cover and water curtain. On the other hand, the transmission mechanism using the rack and pinion has a small risk of sticking due to dust, but is difficult to apply in work requiring high accuracy due to a large backlash and its application range is limited. In addition, any of the ball screw and the rack and pinion is a mechanism for converting the rotational force into direct power, and there are problems such as a large transmission loss and the number of parts.
An object of the present invention is to provide an in-furnace working robot and an in-furnace working method that have a simple configuration, high operation accuracy, and few failures.

The invention according to claim 1 is an in-furnace work robot, and is provided with an elevating device having a mover driven in an axial direction in a substantially cylindrical body case, and a base end coupled to the mover in a freely rotatable manner. And an arm device that forms a V-shaped link, and a wrist mechanism that is attached to the tip of the link of the arm device and holds a tool.
The invention of claim 2 is configured by connecting a plurality of cylindrical magnets.

According to a third aspect of the present invention, there is provided a magnetic position sensor that is disposed in parallel with the operation axis of the lifting device and detects the position of the mover.
According to a fourth aspect of the present invention, in the arm device, each link arm is coupled to the wrist mechanism by a different pin shaft at a coupling portion with the wrist mechanism, and each link arm is flat with the pin shaft as an axial center. The gear is fixed, and the spur gear is configured such that the modules are equal and both are engaged.

According to a fifth aspect of the present invention, the wrist mechanism includes a detachable unit that detaches the tool in a furnace.
The invention according to claim 6 is an in-reactor operation method, wherein the in-reactor operation robot according to claim 1 is carried into the lower part of the core through the upper lattice plate and the core support plate of the nuclear reactor, and the main body via the rotating fixed seat. The lower part of the case is installed on the control rod drive mechanism housing, the upper part of the main body case is fixed to the core support plate via a turning mechanism that rotates the main body case, and the wrist mechanism is driven to work on the in-core equipment. It is assumed that

  The invention of claim 7 is also an in-core work method, and in the in-core work robot, a wire is connected to the mover, and the wire is guided from an upper part of the main body case to a reactor pool, By pulling the wire on the reactor pool, the arm device can be stored in the main body case and recovered outside the reactor.

  According to the present invention, it is possible to provide an in-furnace working robot and an in-furnace working method that have a simple configuration, high operation accuracy, and few failures.

  Hereinafter, first to third embodiments of the present invention will be described with reference to the drawings.

A first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a diagram illustrating the configuration of the in-furnace working robot according to the present embodiment. Reference numeral 1 in the drawing denotes a work robot main body. In the work robot main body 1, an arm device 3 that moves up and down by a lifting device 2 is built in a substantially cylindrical main body case 1a that can be inserted into a furnace. The arm device 3 includes two link arms 3a and 3b having the same length to form a V-shaped link. The shaft motor 4 constituting the lifting device 2 is arranged vertically inside the main body case 1a. The shaft motor 4 is provided with a magnetic position sensor 13 in parallel, and two upper and lower movers 5a and 5b are mounted. Has been.

  The distal ends of the link arms 3a and 3b are coupled by a pin 6 to form a rotatable V-shaped link, and a wrist mechanism 7 is fixed to the pin 6. The base ends of the link arms 3a and 3b are coupled to the movable elements 5a and 5b through pins 8a and 8b so as to be rotatable. Further, a linear guide 9 is arranged in parallel with the shaft of the shaft motor 4, guide tables 10 a and 10 b guided to the linear guide 9 are attached to the movable elements 5 a and 5 b, and the movable elements 5 a and 5 b come into contact with the shaft motor 4. So that it can be driven accurately without the need to

  The shaft motor 4 includes cylindrical permanent magnets with N poles that are N poles, S poles that are S poles that are joined together and aligned in a straight line, and are coupled to each other through a bolt at the center to form a cylindrical shaft. A kind of linear motor is formed through movers 5a and 5b made of electromagnetic coils. The shaft motor 4 has a plurality of movers 5a and 5b on the same shaft, and the movers 5a and 5b can be driven and controlled separately. Such a shaft motor 4 is vertically arranged in the main body case 1a, and the base ends of the link arms 3a and 3b of the V-shaped link constituted by the two link arms 3a and 3b are used as movable elements on the same shaft. It is comprised so that it may drive separately by 5a, 5b. By moving both the movable elements 5a and 5b in the same direction by the same distance, the vertical movement is realized, and by changing the distance between the movable elements 5a and 5b, the opening angle of the link arms 3a and 3b is changed to change the arm device. 3 expansion and contraction is realized. However, since the posture of the wrist mechanism 7 at the tip of the arm devices 3a and 3b changes due to the expansion and contraction of the arm device 3, in order to arbitrarily maintain the posture angle of the wrist mechanism 7 regardless of the expansion and contraction position of the arm device 3. Has at least one degree of freedom of vertical vertical swing (tilt axis) on the wrist, thereby arbitrarily controlling the wrist posture angle.

  The configuration of the magnetic position sensor 13 is as shown in FIG. That is, the sensor part 41 which consists of an electromagnetic coil is provided along the core shaft 40 on which the north pole and south pole of a magnet are laminated | stacked along with the uniform pitch. An induced electric signal generated when the sensor unit 41 moves is converted into position information and displayed using a method such as an induction type or an impedance change type. As shown in FIG. 2, a plurality of sensor portions 41 can be arranged on one core shaft 40. As shown in FIG. 1, the core shaft 40 of the magnetic position sensor 13 is arranged in parallel with the operating axis of the shaft motor 4, and the movers 5a and 5b and the sensor unit 41 are coupled together, and the sensor together with the movers 5a and 5b. The part 41 is configured to move.

  The magnetic position sensor 13 measures the position of the shaft motor 4 on the track, and generates a current position signal and a speed signal necessary for position control and speed control of the shaft motor 4. Further, the magnetic position sensor 13 can detect the current position as an absolute position, and also functions as a limit sensor for determining the origin position and an interlock limit switch for operating limit.

  3 and 4 are views showing a device for attaching tools to the wrist mechanism 7 at the tips of the link arms 3a and 3b. As shown in FIG. 3, the female unit 15 a of the remote attachment / detachment unit mainly includes a taper 16, a ball chuck 17 and an air cylinder 18. As shown in FIG. 4, the male unit 15b of the remote detachable unit is fitted to the female unit 15a, and is configured to be detachable by pneumatic driving or hydraulic driving. The male unit 15b is mainly composed of a pull stud bolt 19, a taper shank 20, and a key groove 21. The male unit 15b is provided with a bolt coupling portion for attaching a tool 22 such as various inspection devices and repair tools.

  As described above, the in-furnace working robot according to the present embodiment is provided with the female unit 15a and the male unit 15b that are remotely attached / detached by pneumatic driving or hydraulic driving based on the tool shank of the machine tool to the wrist mechanism 7 and various kinds of them. Machine tools and inspection tools can be attached and detached in the furnace. With such a configuration, the machine tool (end effector) can be easily exchanged and can be carried into the furnace separately from the robot. Therefore, there are dimensional constraints on both the robot body 1 and the end effector. Alleviated.

  FIG. 5 shows a state where the in-reactor working robot of this embodiment is installed in the reactor. That is, the inner wire 25 is connected to the mover 5a coupled to the link arm 3a above the arm device 3, and the outer guide tube 26 that wraps the inner wire 25 passes through the inside of the in-furnace work robot and goes outside from the upper part. Since it is connected to the operation area on the upper surface of the pool, the inner wire 25 can be pulled upward by an operator or a drive mechanism.

  When the shaft motor 4 is not excited, no thrust is generated and the current position cannot be maintained. Therefore, when the servo of the shaft motor 4 is turned off or an overload occurs, the servo current stops, the two movers 5a and 5b drop to the lowermost end, and the link arms 3a and 3b are in the most protruding state. However, with the above-described configuration, it becomes possible to pull up the movable element 5a connected to the upper link arm 3a remotely from the operation floor by pulling the inner wire 25, and at the time of failure or abnormality Also, the link arms 3a and 3b can be returned to the contraction direction (storage posture).

  In the in-reactor work robot of this embodiment, the shape of the work robot main body 1 is substantially cylindrical, and can be easily inserted and installed in the reactor pressure vessel. As shown in FIG. 5, a turning mechanism 30 is attached to the upper end, and a fixed seat 31 is attached to the lower end. Although not shown, the turning mechanism 30 has a motor and a rotating shaft inside, and allows the work robot body 1 to rotate horizontally. A positioning dog 33 is attached to a side surface of the turning mechanism 30, and the dog 33 is fitted to a positioning pin 34 on the core support plate 32 of the reactor internal structure. The fixed seat 31 is fitted into a hole at the upper end of the CRD (control rod drive mechanism) housing 35. The fixed seat 31 has a built-in bearing, and is rotatable while receiving the load of the work robot body 1.

  The in-furnace working robot of the present embodiment is configured such that the entire link arms 3a and 3b including the wrist mechanism 7 can be accommodated in the main body case 1a when the shaft motor 4 is driven and the link arms 3a and 3b are housed in the main body case 1a. Then, it passes through the lattice of the upper lattice plate (not shown) and the hole of the core support plate 32 and is installed on the CRD housing 35.

  After installation, by driving the movers 5a and 5b of the shaft motor 4 in the furnace, the shape and the vertical position of the arm device 3 are changed and adjusted, and a predetermined operation is performed. When the movers 5a and 5b are simultaneously moved in the same direction by the same distance, the shape of the arm device 3 is moved up and down without changing the shape, which is the same as driving only the lifting shaft alone. Further, if the movers 5a and 5b are simultaneously moved in the opposite direction by the same distance, the entire position of the arm device 3 is not changed, and this is the same as driving the telescopic shaft of the arm device alone. That is, the raising / lowering and expansion / contraction of the arm device 3 can be driven and controlled by the raising / lowering control of the movers 5a, 5b.

  According to this embodiment, the operation of the shaft motor 4 can be detected by the magnetic position sensor 13, and a position feedback signal for servo control of the shaft motor 4 is obtained from the position signal obtained from the magnetic position sensor 13. Can do. The magnetic position sensor 13 can measure the absolute position. By using the magnetic position sensor 13 having a measurement stroke equal to or greater than the stroke of the shaft motor 4, the origin position return is performed simultaneously with the detection of the position feedback signal. The origin position detection and operation limit detection can be performed.

  Further, according to the present embodiment, various tools 22 can be easily attached to the work robot body 1a by remote control in the water in the furnace. Furthermore, even when the shaft motor 4 is servo-off due to an overload or malfunctions due to a failure, the arm device 3 can be prevented from dropping by the tension of the inner wire 25. Thereafter, by pulling the inner wire 25 and pulling up the link arm 3a, the arm device 3 can be returned to the storage posture without driving the shaft motor 4.

  The present embodiment has a structure in which the two movable elements 5a and 5b are moved up and down on the same shaft motor 4, and the entire stroke of the shaft can be used effectively, and the vertical movement range is large. In addition, since it is a linear drive, it is possible to achieve high speed and high acceleration / deceleration with little transmission loss and high accuracy because there is little backlash. Furthermore, there are few components, and the effect of cost reduction can be expected, for example, the number of parts is reduced, and the assembly cost and parts cost are reduced.

  In-furnace working robots perform maintenance and repair work in the furnace water, so all electric drive units must be submerged, but the shaft motor 4 has no sliding parts such as bearings and is movable. The child electromagnetic coil is a highly water-resistant motor that is covered with a seal and insulated from the outside, and has high reliability. Further, in the shaft motor 4, there is little dust mixing and biting in principle, and no countermeasures are required. In general, polishing and welding work in water is an environment in which clad and cutting dust are discharged into water, but it can withstand such an environment.

  Furthermore, the shaft motor is equipped with a magnetic position sensor that can measure the absolute position in parallel with the shaft motor, so that the functions of origin position, origin return, and operation limit detection can be provided by a single position sensor. Yes, both the sensor and the amplifier can reduce the number of parts.

  In the in-furnace working robot of the present embodiment, the arm device 3 may not move in the event of a failure. However, it is possible to connect one inner wire 25 for arm recovery to the mover 5a of the shaft motor 4. Can be easily returned to the stowed position.

  FIG. 6 is a diagram showing a work robot body provided in the in-furnace work robot of the second embodiment of the present invention. Reference numeral 1 in the figure denotes a work robot main body. The work robot main body 1 includes an arm device 3 that moves up and down by a lifting device 2 in a substantially cylindrical main body case 1a that can be inserted into a furnace. The arm device 3 includes two link arms 3a and 3b having the same length to form a V-shaped link. The linear motor 11 constituting the lifting device 2 is disposed vertically inside the main body case 1a, and two movers 12a and 12b are mounted on the linear motor 11.

  The distal ends of the link arms 3a and 3b are coupled by a pin 6 so as to be rotatable, and a wrist mechanism 7 is attached to the pin 6. The base ends of the link arms 3a and 3b are rotatably coupled to the movers 12a and 12b via pins 8a and 8b. Further, a linear guide 9 is arranged in parallel with the axis of the linear motor 11, guide tables 10 a and 10 b guided by the linear guide 9 are attached to the movable elements 5 a and 5 b, and the movable elements 12 a and 12 b are magnets of the linear motor 11. It is possible to slide while maintaining a certain gap accurately without contacting the track.

  The linear motor 11 in the second embodiment has the same function as the shaft motor 4 in the first embodiment and acts in the same manner. The operations of carrying in, installing, and carrying out the in-furnace working robot of this embodiment into the furnace are the same as those in the first embodiment.

  FIG. 7 is a diagram showing a work robot body provided in the in-furnace work robot of the present embodiment. Similar to the configuration of the first embodiment (FIG. 1) and the second embodiment (FIG. 6), except that the link arms 3a and 3b are not supported by the same pin 6, That is, the pins 6a and 6b are separately supported rotatably. Further, a spur gear 14a is attached to the link arm 3a, and a spur gear 14b is attached to the link arm 3b, and the two mesh with each other. The spur gears 14a and 14b are gears having the same module and the same pitch circle. The pitch radius is equal to 1/2 the distance between the pins 6a and 6b. The distance between the pins 8a and 6a of the link arm 3a and the distance between the pins 8b and 6b of the link arm 3b are the same. The wrist mechanism 7 is connected to the link arms 3 a and 3 b by pins 6 a and 6 b, and the spur gears 14 a and 14 b are meshed so that the wrist shaft is parallel to the lifting shaft of the shaft motor 4.

  This structure is a trapezoidal arm device. The trapezoidal upper base is connected to the wrist mechanism 7 and the lower base is driven by the shaft motor 4. In this configuration, the pins 6a and 6b on the wrist mechanism 7 side are engaged with spur gears 14a and 14b. By matching, the posture of the wrist mechanism 7 is always maintained parallel to the axis of the shaft motor 4. Accordingly, since the posture of the arm wrist is always constant during the lifting and lowering operation of the arm device 3 and the arm expansion and contraction, it is necessary to provide a tilt axis on the arm wrist when the posture of the arm wrist needs to be kept constant. Disappear.

  In this embodiment, the spur gears 14a and 14b are provided at the joint between the arm device 3 and the wrist mechanism 7, so that the posture of the wrist mechanism 7 is kept constant regardless of the posture of the link arms 3a and 3b. Can do. In particular, when the wrist mechanism 7 is assembled in parallel with the drive shaft of the shaft motor 4 (or linear motor 11), the posture of the tool 22 can always be kept vertical regardless of the posture of the link arms 3a and 3b. In the in-furnace operation, the in-furnace operation is facilitated by being parallel to the shroud 37.

  FIG. 8 shows a state where the in-reactor working robot of this embodiment is installed in the reactor. That is, the inner wire 25 is connected to the mover 5a coupled to the link arm 3a above the arm device 3, and the outer guide tube 26 that wraps the inner wire 25 passes through the inside of the in-furnace work robot and goes outside from the upper part. The inner wire 25 can be pulled by an operator or a drive mechanism. According to this configuration, when the servo current of the shaft motor 4 is turned off or an overload occurs, the servo current stops, the two movers 5a and 5b drop to the lowermost end, and the link arms 3a and 3b are in the state where they protrude most. In addition, by retracting the inner wire 25, the mover 5a connected to the upper link arm 3a can be pulled up manually from the operation floor, and the link arms 3a and 3b can be contracted even in the event of a failure or abnormality. It can be returned to the direction (storage posture).

The principal part of the in-furnace working robot of 1st Example of this invention is shown, (a) is a longitudinal cross-sectional view, (b) is a plane sectional view which follows the bb line of (a). The magnetic position sensor with which the in-furnace working robot of 1st Example of this invention is equipped is shown, (a) is a longitudinal cross-sectional view, (b) is sectional drawing which follows the bb line of (a). The figure which shows the female unit which attaches a tool in the in-furnace working robot of 1st Example of this invention. The figure which shows the male unit attached to or detached from the female unit shown in FIG. 3 in the in-furnace working robot of the 1st Example of this invention. The elevation view which shows the operation method in the furnace in the 1st example of this invention. The principal part of the in-furnace working robot of the 2nd Example of this invention is shown, (a) is a longitudinal cross-sectional view, (b) is a plane sectional view which follows the bb line of (a). The principal part of the in-furnace working robot of the 3rd Example of this invention is shown, (a) is a longitudinal cross-sectional view, (b) is a plane sectional view which follows the bb line of (a). The elevation view which shows the in-furnace work method in the 3rd example of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Work robot main body, 1a ... Main body case, 2 ... Lifting device, 3 ... Arm apparatus, 3a, 3b ... Link arm, 4 ... Shaft motor, 5a, 5b ... Movable, 6, 6a, 6b ... Pin, 7 ... Wrist mechanism, 8a, 8b ... pin, 9 ... linear guide, 10a, 10b ... guide table, 11 ... linear motor magnet track, 12a, 12b ... mover, 13 ... magnetic position sensor, 14a, 14b ... spur gear, 15a ... female unit, 15b ... male unit, 16 ... taper, 17 ... ball chuck, 18 ... air cylinder, 19 ... pull stud bolt, 20 ... taper shank, 21 ... keyway, 22 ... tool, 25 ... inner wire, 26 ... Outer guide tube, 30 ... turning mechanism, 31 ... fixed seat, 32 ... core support plate, 33 ... dog, 34 ... positioning pin, 35 ... CRD housing, 3 ... shroud, 38, 39 ... cable, 40 ... core shaft, 41 ... sensor unit.

Claims (7)

  A lifting device having a mover that is driven in an axial direction in a substantially cylindrical main body case, an arm device that is pivotally coupled to the mover to form a V-shaped link, and the arm device And a wrist mechanism for holding a tool attached to the end of the link.   The in-furnace work robot according to claim 1, wherein the lifting device is formed by connecting a plurality of cylindrical magnets.   The in-furnace work robot according to claim 1, further comprising a magnetic position sensor that is arranged in parallel with an operation axis of the lifting device and detects a position of the mover.   In the arm device, each link arm is coupled to the wrist mechanism by a different pin shaft at a coupling portion with the wrist mechanism, and a spur gear around the pin shaft is fixed to each link arm. 2. The in-furnace working robot according to claim 1, wherein the gears have the same module and both mesh with each other.   The in-furnace working robot according to claim 1, wherein the wrist mechanism includes an attaching / detaching unit for attaching / detaching the tool in the furnace.   The in-reactor working robot according to claim 1 is carried into the lower part of the core through the upper lattice plate and the core support plate of the reactor, and the lower part of the main body case is installed on the control rod drive mechanism housing via the rotating fixed seat. An in-furnace working method characterized in that an upper part of the main body case is fixed to a core support plate via a turning mechanism for rotating the main body case, and the wrist mechanism is driven to work on in-furnace equipment. The in-reactor work robot according to claim 1, wherein a wire is connected to the mover, the wire is guided from an upper part of the main body case to the reactor pool, and the wire on the reactor pool is pulled. An in-furnace working method characterized in that the arm device is housed in the main body case and can be recovered outside the furnace.

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