JPS6158000B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a heat exchanger having a large number of tubes, and a device for installing a blind plug at the end of the tube to prevent the inflow of fluid when a defect occurs in the tube. Regarding.

In a heat exchanger that has a large number of heat transfer tubes or evaporation tubes, if a defect such as a scratch occurs on the tube, the end of the defective tube should be closed with a blind plug as a means of repairing the heat exchanger. There is a way to close the tube and prevent fluid from flowing into it. To describe this method more specifically, as shown in FIG. 1a, a blind welding plug 01 is fitted into the hole 03 of the tube plate 02 to which the defective pipe is connected, as shown in FIG. 1b,
This is then welded as shown in Figure 1c. In heat exchangers in which the tube group is oriented vertically, the blind plug 01 inserted into the hole 03 may fall off, so conventionally, the blind plug 01 inserted into the hole 03 may fall off.
1 is press-fitted and temporarily held. On the other hand, when performing such work, there are some places where people cannot approach, so automation and remote control are desired, but pressing in the blind plug 01 requires a considerably large impact force. Since a large amount of force is required to hold the device, it is difficult to reduce the size and weight of the device to the extent that it can be mounted on a remote automatic guide device. Therefore, a blind plug was developed that utilizes the elastic force of a leaf spring and can be attached to a hole with a small amount of force, while also exhibiting sufficient temporary holding power. A special mounting device is required for this purpose.

The present invention provides a newly devised device for installing a blind plug into a hole in a tube sheet or a hole in a pipe, etc.
The purpose is to enable remote automatic operation of blind plug installation work. To achieve this purpose, the mounting device of the present invention has a structure in which a frame is held by a guide device installed below the ends of a large number of upwardly facing holes and movable in any direction, and a guide cylinder is driven and rotated. is supported by the frame, and a plug holder having a blind plug fitting part attached to the hole on the upper part is inserted into the guide cylinder so as to be movable only in the vertical direction, and a plug holder is inserted into the plug holder via a flexible shaft. The present invention is characterized in that the rods are connected to each other and the rods are movable up and down by a cylinder mechanism, and a guide member is attached to the frame body to be attached to a hole other than the hole in which the blind plug is attached.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a blind plug mounting device according to the present invention will be described below with reference to the drawings.

FIG. 2 shows a perspective external appearance of a state in which a blind plug is attached to the end of the thin tube 3 of the heat exchanger 2 using the device 1 according to the embodiment. In this heat exchanger 2, a large number of thin tubes 3 through which fluid passes are connected vertically to a tube plate 5 at the lower part of the cylindrical shell 4, and below the tube plate 5, the cylindrical shell 4, and a partition wall 6. There is a water chamber 7 divided into sections, and a blind plug mounting device 1 is installed in the water chamber 7.

The blind plug mounting device 1 of this embodiment employs a manipulator 8 as its guide device. The structure of this manipulator 8 is shown in FIGS.
As shown in the figure, a pedestal 11 is connected to the tip of a fixed pedestal 10 that is fixed using a manhole 9 provided in a water chamber 7, and is supported by a support ball 12 and a support arm 13. A swivel base 14 is installed on the pedestal 11, and an extendable main arm 15 is installed on the swivel base 14.
Main arm 15 and swivel base 1
4 are connected by an elevating arm 16, a swinging mechanism 17 is installed at the tip of the main arm 15, and an attachment 19 for holding the device body 18 is connected to the swinging mechanism 17 so as to be freely pivotable.
It is also possible to use a walking robot as the guide device.

As shown in FIG. 4a, the attachment 19 has a mounting hole 21 at one end of a small arm 20 for fitting into the tip of the manipulator 8, and a mounting hole 21 for holding the device main body 18 at the other end. A semi-cylindrical portion 22 is provided. This attachment 19
is bolted to the tip of the manipulator 8 using bolt holes 23 around the mounting hole 21. Two guiding key grooves 24 are formed in parallel in the axial direction on both sides of the inner surface of the semi-cylindrical portion 22, relief grooves 25 are formed in the vicinity of these guiding key grooves 24, and these two grooves 24 ,25
A transition groove 26 is formed by connecting the two. A lock cam 27 is supported by a pin 28 at an upper portion near the center of the inner surface of the semi-cylindrical portion 22, and is in contact with a piston 30 held by a spring 29. A spring force is always applied to the lock cam 27 in a direction that causes it to protrude from the inner surface of the semi-cylindrical portion 22. As shown in FIG. 5, the tip of this lock cam 27 is
It has a roughly trapezoidal shape with two slopes. The piston 30 and the spring 29 are housed in a cylinder 31 formed in the small arm 20, and the cylinder 31 has a pneumatic hole 3 formed in the small arm 20.
2. Compressed air is supplied through a joint 33 connected to this and a pneumatic tube 34 connected to the joint 33.

Figures 6a, b, and c show a blind plug 35 that is attached to the tube end by the attachment device. This blind plug 35 has a tapered plug body 36 with a rectangular (for example, hexagonal) tool hole 3 extending from the rear end surface.
7, and a plate-like fin 3 having spring elasticity and having a spiral groove 38 carved on the surface at the tip of the plug body.
A large number of plugs 9 are arranged in a ring shape with gaps between them, and are fastened to bolts 40 protruding from the plug body 36 with nuts 41. In reality, the fins 39 are made by slotting a cylindrical member as a gap.

a device main body 18 that is held by the attachment 19 and applies upward force and rotational force to the blind plug 35 to attach the blind plug 35 to the end of the pipe 3;
are shown in Fig. 4 b, c and Fig. 7 a, b. The device main body 18 includes a mounting mechanism for the attachment 19, a blind plug lifting mechanism, a blind plug rotation mechanism, a guide mechanism for holding the device main body 18, and the like.

A fitting cylindrical portion 43 that matches the semi-cylindrical portion 22 is integrally provided on the frame (base) 42 of the device main body 18, and guide keys 44 are provided on the surface of the fitting cylindrical portion 43 corresponding to the guiding key grooves 24, respectively. Two lock plates 46 are provided on the upper and lower sides, and at a position facing the lock cam 27, a lock plate 46 having an engaging groove 45 having the same shape as the tip of the lock cam 27 is embedded. The engagement of these keys 44 with the key groove 24 and the engagement groove 45 with the lock cam 27 causes
8 is attached to the attachment 19.

A cylinder body 47 is also integrally attached to the frame body 42 of the apparatus main body 18, and a spline nut 48 is rotatably supported therein as a guide cylinder. A plug receiver 49 is spline-fitted into the spline nut 48 and is movable only in the vertical direction. The blind plug 3 is attached to the upper part of the plug receiver 49.
A wrench portion 50 that is fitted into the tool hole 37 of No. 5 is provided in a protruding manner. A shaft 52 is supported within the plug receiver 49 via a bearing 51, and a rod 54 is connected to the shaft 52 via a flexible shaft 53. This rod 54 extends downward and is connected to a piston 56 of a cylinder 55 provided on the underside of the frame 42. An ascending pneumatic hole 57 and a descending pneumatic hole 58 are formed in the cylinder 55, and pneumatic tubes 59 and 60 are connected to each of them. A magnet 61 is embedded in the circumferential surface of the piston 56, and magnetic sensors 62 and 63 are installed corresponding to the magnet 61 when the piston 56 is in the raised and lowered positions. or,
The plug receiver 49 connects the sensor receiver 64 so that it can be pushed up. The sensor receiver 64 holds a proximity sensor 65, has a rod 66, and is adapted to receive the reaction force of a compression spring 67. In addition, 68 is Rod 6
6 is a bearing, and 69 is a guide piston.

On the other hand, a gear 70 is formed at the lower end of the spline nut 48, a gear 72 with a gear shaft 71 supported by the frame 42 is meshed with the gear 70, and two reducers 7 are connected to the gear 71.
A motor 75 is connected via 3 and 74.
A magnet 76 is provided on the circumferential surface of the gear shaft 65.
Several magnetic sensors 77 are buried there, and a magnetic sensor 77
is installed.

A guide shaft 78 is provided as a guide member for holding the device main body 18 in that position after the plug receiver 49 is aligned with the target pipe 3. As shown in FIGS. 4b and 4c and 7a and 7b, there are a pair of guide shafts 78 corresponding to two pipes 3 adjacent to the pipe 3 to which the blind plug 49 is installed, and It is attached to the side using a screw stand 79 and screws 80. A cylindrical rising piston 82 is fitted into an outer cylinder 81 that is integrated with the screw head 79, and a number of fixing claws 83 having an inner tapered surface are incorporated into the tip thereof so as to be able to protrude in the radial direction. .
The fixed claw 83 is held by an O-ring 84 placed around it. The upper part of an inner cylinder 85 is connected to the inside of the rising piston 82 , and the inner cylinder 85 extends downward through a boundary part 86 provided in the middle of the outer cylinder 81 . It is integrated with a descending piston 88 having a diameter. Inside the inner cylinder 85 is a piston rod 8.
9 passes through, and a taper collet 90 is provided at the tip thereof to slidably contact the tapered surface of the fixing claw 83, and the lower end is provided with a descending piston 88.
It is integrated with a clamp piston 91 incorporated in the cylinder portion 87 of. Clamp piston 91
An upward spring force is applied to the clamp by a compression spring 92, and a clamp air pressure hole 93 is formed in the upper part. Above and below the boundary portion 86, the outer cylinder 81 has a rising air pressure hole 94 and a falling air pressure hole 9.
5 are formed, each having a pneumatic tube 96,
97 is connected. A magnet 98 is embedded in the circumferential surface of the descending piston 88, and magnetic sensors 99, 100 are installed opposite the magnet 98 at the ascending and descending ends of the descending piston 88. A magnet 101 is also embedded in the clamp piston 91, and a magnetic sensor 102 is installed opposite the clamp position.

Next, the operation of attaching a blind plug using the embodiment apparatus having the above configuration will be explained for each function of each part.

Device body 18 attached to manipulator 8
is guided to an arbitrary position within the water chamber 7 by the rotation, expansion and contraction, and elevation of the main arm 15. Therefore,
It can also be carried under the tube 3 that requires treatment. Here, the device body 1 is rotated by the swinging mechanism 17.
8 can be corrected, and the main body 18 of the device can be kept in a constant posture (vertical here) with respect to the tube plate 5. That is, the main body 18 of the apparatus can be guided to a desired position and in a desired posture by remote control.

When replacing the device main body 18, the attachment 19 of the manipulator 8 comes directly above the manhole 7 as shown by the two-dot chain line in FIG. 3, so that the replacement work can be easily performed. The details of the exchange operation will be described below.

Align the guide key 44 of the fitting cylindrical part 43 with the guide key groove 24 of the semi-cylindrical part 22, and then press the device main body 18.
When inserted from the bottom of the attachment 19, its rotation is restricted by the action of the guide key 44. When the device main body 18 is further pushed up, the tip of the fitting cylindrical portion 43 touches the lock cam 2, as shown in FIG. 5a.
7 is pushed in against the spring force until the engaging groove 45 is at the same position as the lock cam 27. When the engagement groove 45 reaches the predetermined position, the lock cam 27 returns due to the spring force of the spring 29, and the fifth
As shown in Figure b, they are in a mutually engaged state.
If air pressure is applied to the cylinder 31 in this state, the piston 30 will press against the lock cam 27 and the two will be completely fixed. When detaching, the pressure is released from the cylinder 31 and the device body 18 is pushed up with a stronger force than when inserting due to the difference in the inclination of the taper, and the lock cam 27 overcomes the spring force and rotates around the pin 28, as shown in Fig. 5c. As shown, the engagement groove 45 and the lock cam 27 are separated. In this state, the device body 1
8, the guide key 44 moves into the transition groove 26.
The device body 18 can be pulled out from the attachment 19 without being affected by the locking plate 46.

Manipulator 8 via attachment 19
The main body 18 of the device held by the main body 18 is guided below the required pipe 3. At this time, the piston 56 of the lifting mechanism is at the lower end, and the blind plug 35 is placed on the plug receiver 49. In this state, the blind plug 35 is completely buried in the spline nut 48, so that the blind plug 35 is prevented from falling off. After the guidance is completed, when air pressure is applied in the order of air tube 59 → rising air pressure hole 57 → cylinder 55, the piston 56 rises,
As a result, rod 54, flexible shaft 5
3. The shaft 52 and the plug receiver 49 rise, and the blind plug 35 rises to the inlet of the pipe 3. At this time, since the tip of the fin 39 of the blind plug 35 is tapered, it is easily inserted into the tube 3 up to the end of the spiral groove 38. When the motor 75 is rotated in this state,
Rotation is transmitted through the reducer 74, 73 → gear 72 → gear 70 → spline nut 48 → plug receiver 49 → wrench part 50, and the blind plug 35, that is, the fin 39, is prevented from rotating by the wrench part 50 and the tool hole 37. Rotate. When the fin 39 rotates, the spiral groove 38
Due to the screw effect, the blind plug 35 is screwed into the pipe 3 while compressing the fins 39. Therefore, surface pressure is generated on the tube surface due to the spring reaction force of the fins 39,
In addition, the friction increasing effect of the spiral groove 38 allows it to be removed and retained. Furthermore, when screwed in, the plug body 36
The outer surface and the inner surface of the tube 3 come into close contact, the load on the motor 69 increases, the motor 75 stops, and the insertion is completed. A proximity sensor is provided to indirectly measure the insertion amount at this time. When the plug receiver 49 rises at the same time as the blind plug 35, the sensor receiver 64 also rises by overcoming the reaction force of the compression spring 67. Since the proximity sensor 65 is installed keeping its relative position to the plug receiver 49 surface, by measuring the distance to the tube plate 5 surface in this state, it is possible to know the insertion amount of the blind plug 35, It is possible to know whether or not the process was carried out reliably. Furthermore, the lifting rod 54 is mounted on the bearing 5.
Since it is indirectly connected to the plug receiver 49 via 1,
The plug receiver 49 is free from the shaft 52, and the reliability of the cylinder 55 can be improved.
Due to the operation of the flexible shaft 53, it is not possible to restrain the distal end from swinging, making it easier to deal with misalignment and the like. However, spline nut 4
There is a gap between 8 and the plug receiver 49.

Regarding the detection system, magnetic sensors 62 and 63 operate at the upper end and lower end of the piston 56, respectively, and can detect the end of the stroke. The magnetic sensor 77 operates in pulses when the magnet 70 approaches and separates, and by monitoring this pulse, the motor 75 is activated.
The rotational state of the blind plug 35 can be known through the rotational state of the blind plug 35.

Regarding the guide shaft 78, if air pressure is applied to the rising air pressure hole 94, all parts connected to the rising piston 82 will rise, and the fixing claw 83 will be inserted into the tube 3. In this state, if air pressure is applied to the clamp air pressure hole 93, the crank piston 91 overcomes the compression spring 92 and descends, pulling the piston rod 89 down. At the same time, the taper collet 90 is also lowered,
The fixing claws 83 are pushed apart to be tightly fixed to the inner surface of the tube 3. With this action, the main body 18 of the device is securely fixed to the tube plate 5, and the adverse effects of insertion reaction force can be prevented. When descending, the pneumatic pressure in the clamp pneumatic hole 93
OFF → return action of compression spring 92 → rise of clamp piston 91 → contraction action of O-ring 84 → reduction in diameter of fixed claw 83 and separation from inner surface of tube 3 → pneumatic pressure of rising pneumatic hole 94 OFF → descending pneumatic hole 95 air pressure ON
→ Lowering of the connecting portion of the inner cylinder 85 → Pulling out the fixing claw 83 from the tube 3 and separating it. In addition, the fixed claw 83
When the tube is completely inserted into the tube 3, the magnet 98 activates the upper end magnetic sensor 99, when clamping, the magnet 101 activates the clamp confirmation sensor 102, and when it is lowered (at the lower end position of the fixed claw), the magnet 98 activates the lower end magnetic sensor 100. The guide shaft 78 can be operated and the position of the guide shaft 78 can be monitored accordingly.

The above operation is as follows: installation of the device main body 18 → supply of the blind plug 35 → operation of the manipulator 8 → required pipe 3
Downward guidance → Device clamping by movement of guide shaft 78 → Insertion of blind plug 35 → Confirmation of completion of insertion of blind plug 35 → Unclamping of guide shaft 78 → Return to blind plug 35 supply position by manipulator 8 →
The procedure of supplying the blind plugs 35 is repeated, and after a predetermined number of blind plugs 35 have been inserted, the device main body 18 is removed. Therefore, the entire process is done remotely.

As described above with reference to one embodiment, the blind plug installation device according to the present invention can completely complete the process of installing blind plugs into pipes, which was previously considered impossible due to the drive-in blind plug holding method. It becomes possible to achieve automatic remote control, thereby achieving a significant improvement in the working environment for workers.

[Brief explanation of the drawing]

Figures 1a, b, and c are process diagrams showing conventional blind plug construction, Figure 2 is a perspective view showing the construction state of a blind plug according to an embodiment of the present invention, and Figure 3 is a front view of the manipulator. Figure 4a is a perspective view of the attachment, Figure 4b is a partially exploded perspective view of the device body, Figure 4c is a perspective view of the attachment and device body combined, and Figures 5a and b. , c is a partial view showing the state of engagement between the lock cam and the meshing groove;
Figures 6a, b, and c are partial sectional views, right side views, and left side views of the blind plug, and Figures 7a, b are sectional views of the main body of the device. In the drawings, 1 is a blind plug installation device, 3 is a tube, 5 is a tube plate, 8 is a manipulator, 18 is a main body of the device, 1
9 is an attachment, 35 is a blind plug, 42 is a frame, 48 is a spline nut, 49 is a plug holder,
50 is a wrench part, 53 is a flexible shaft,
75 is a motor, and 78 is a guide shaft.

Claims (1)

[Claims] 1. A frame is held by a guide device installed below the ends of a large number of upwardly facing holes and movable in any direction, a guide tube that is driven and rotated is supported by the frame, and a blind plug is attached to the hole. A plug holder having a fitting portion at the top thereof is inserted movably only in the vertical direction into the guide cylinder, and a rod is connected to the plug holder via a flexible shaft, and the rod can be moved up and down by a cylinder mechanism. A blind plug mounting device further comprising a guide member mounted on the frame body to be mounted in a hole other than the hole in which the blind plug is mounted.