JPH06238441A - Torus ring automatic welding equipment of turbine high pressure water feed heating device - Google Patents

Abstract

PURPOSE:To automatically and surely execute the work to weld/plug the cut section after the torus ring of high pressure water feed heating device for a steam power generation station is temporarily cut in the peripheral direction at checking/repairing of heating device. CONSTITUTION:A rotating arm 4, which is horizontally rotated around a support shaft by a rotating means 3, is mounted to a mounting base 2 vertically arranged attachable/detachable on a support shaft 1 projecting at the rear side center of a channel head 102 of heating device, on this arm, a copying stage 5 movable up/down and forward/backward toward a welding section (a) is mounted, on the copying stage, a welding torch and welding position copying sensor 9 are mounted. The sensor plays to learn the desirable traveling locus of tip of the welding torch 6, in order to hold the welding torch tip to the prescribed position for the welding sectionat automatic welding. A welding wire feed device 8 is mounted on the rotating arm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fitting formed around a water chamber lid fitted to an open lower end of a cylindrical water chamber of a high pressure feed water heater (bleach lock head type) of a thermal power plant. The torus ring, which has a substantially C-shaped cross section, is welded across the gap to provide a pressure-resistant seal. The torus ring is temporarily cut in the circumferential direction to remove the water chamber lid each time the inside of the heater is inspected or repaired. However, the present invention relates to a torus ring automatic welding device of a turbine high-pressure feed water heater for welding and closing this cut point after the inspection / repair is completed and the water chamber lid is attached.

[0002]

2. Description of the Related Art FIGS. 12 to 14 are explanatory views of a prior art showing how to cut a torus ring for reference. A water chamber lid 102 is fitted to the open lower end of the cylindrical water chamber 101 of the high-pressure feed water heater 100, and as shown in FIG. A torus ring 200 is welded across a gap g between the water chamber 101 and the water chamber lid 102, in which steel pipes are cut into a ring shape so that the cross section has a substantially C shape. . Then, in order to cut the torus ring 200 as described above, the swivel shaft 302 of the swivel arm 301 is screwed into the screw hole 102a provided at the center of the lower surface of the water chamber lid 102, and attached to the tip of the swivel arm 301. Gas torch 3
03 was manually operated to cut the torus ring 200. In that case, as shown in FIG.
Since the cut surface has a concave and convex slit shape, in order to return to the original state by welding after inspection and repair, this cut point m is given a reference numeral n and is shown as a V-cut groove shape (groove shape). ) Had to be arranged. And, conventionally, the welding work at the cutting point has been entirely dependent on humans.

[0003]

The above-mentioned cutting work and the work of arranging the cut portions in the V-cut groove shape require a considerably skilled technique and much time. However, due to the installation situation of the high-pressure feed water heater, this cutting work is a work in a narrow space, and especially the shaping and processing of the cut surface on the water chamber side is performed in an unreasonable posture bent upwards. Because it must be done, young people are shunned and there is concern that future workers will be secured. Therefore, the inventor of the present application can automatically perform the cutting work first without resorting to manual labor, and can almost eliminate the post-processing work for shaping the cut portion into a V-cut groove shape for re-welding. We are developing an automatic torus ring cutting device for high pressure feed water heaters. However, even if the cutting work can be automated,
It is one-handed if the subsequent welding work cannot be automated. However, since high-temperature, high-pressure water circulates inside the high-pressure feed water heater, strict welding reliability is required. Where
Since this welding work also has to be performed in a cramped posture in which it bends upward as in the above-mentioned cutting work, there is a risk that the finish of welding will be adversely affected. Therefore, an object of the present invention is to temporarily cut the torus ring of a high-pressure feed water heater installed in a thermal power plant in the circumferential direction in order to remove the water chamber lid every time the heater is inspected and repaired, and then this cutting is performed. It is an object of the present invention to provide an automatic torus ring welding machine for a high-pressure feed water heater, which enables the work of welding and closing points to be automatically and reliably performed without relying on human labor.

[0004]

In order to achieve the above object, a torus ring automatic welding machine for a turbine high pressure feed water heater according to the present invention is provided at an open lower end of a cylindrical water chamber 101 constituting the high pressure feed water heater. The torus ring 200 having a substantially C-shaped cross section, which is welded across the gap to seal the fitting gap of the fitted water chamber lid 102, is provided in the water chamber each time the inside of the heater is inspected or repaired. In order to remove the lid 102, the lid 102 is temporarily cut in the circumferential direction.
A device for welding the cut portion after the repair is completed and the water chamber lid 102 is attached, and is vertically detachably attached to a support shaft 1 projecting from the center of the lower surface side of the water chamber lid 102. Attached to the attachment base 2, a rotary arm 4 attached to the attachment base 2 and horizontally rotated around the support shaft 1 by a rotating means 3, and attached to the rotary arm 4. , A copying stage 5 which can be displaced in the vertical and longitudinal directions with reference to the center line of the weld groove toward the welding location a, a welding torch 6 assembled to the copying stage 5, and the rotary arm 4. In order to hold the attached welding wire feeder 8, the tip of the welding torch 6 which is rotated together with the rotating arm 4 and the welding location a in a predetermined positional relationship, the welding stage is mounted on the copying stage 5. Of the tip of the welding torch 6 which is being welded and is being automatically welded. The welding position scanning sensor 9 for learning a favorable movement trajectory and the scanning stage 5 are displaced during automatic welding based on the learning information of the welding position scanning sensor 9, and a series of welding operations are arbitrarily set. The operation control unit 72 that automatically advances according to the operation program described above is provided. Then, the ring gear 21 and the fixed side rings 23a of the cross roller bearings 23 are attached to the mounting base 2 concentrically with the support shaft 1, respectively, and the rotary side ring 23 of the cross roller bearings 23 is attached.
It is preferable that the rotating arm 4 and the rotating means 3 are attached to b, and the pinion 36 rotated by the rotating means 3 is meshed with the ring gear 21.

[0005]

When the high pressure feed water heater is inspected and repaired, the V-shaped groove of the torus ring 200, which has been temporarily cut in its circumferential direction, is welded and filled after inspection and repair.
The mounting base 2 is horizontally attached to the support shaft 1 projecting from the center of the lower surface of the device, and the main body of the apparatus is detachably hung on the mounting base 2 and the welding torch 6 is set for use. Then, first, as a preparatory step, the detection portion of the welding position scanning sensor 9 attached to the scanning stage 5 provided on the rotating arm 4 of the mounting base 2 is brought into contact with the welding start position of the welding location a, and then the rotating means. If the rotating arm 4 is rotated once by 3,
The welding position tracing sensor 9 learns a desirable movement locus of the tip of the welding torch 6 for keeping the welding torch 6 during automatic welding in a predetermined positional relationship with respect to the welding location, and inputs it to the operation control unit 72. To memorize. Therefore, when an arbitrary operation program is set in the operation control unit 72 and the automatic welding device is operated, the copying stage 5 is automatically displaced based on the stored information and attached to the copying stage 5. The tip of the welding torch 6 and the welding point a are continuously kept in a predetermined positional relationship, and the cutting point of the torus ring 200 is reliably welded.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. First, the turbine high-pressure feed water heater 100 has a cylindrical water chamber 1 as shown in FIGS.
The water chamber lid 102 is fitted to the open lower end of 01. Then, both mating surfaces facing each other are respectively formed in the shape of an internal gear and an external gear, and the water chamber lid 102 is sufficiently inserted into the open lower end of the water chamber 101 and is rotated by the tooth width. As a result, as shown in the drawing, the inner teeth and the outer teeth are assembled in a state of being vertically overlapped with each other so as to withstand high pressure. A screw hole 102a is provided at the center of the lower surface of the water chamber lid 102.
Regarding the size of the torus ring 200 having a shape in which a metal pipe is bent into a ring shape, in this embodiment, the ring diameter is about 1000 mm, the pipe diameter is about 51 mm, and the pipe wall thickness is about 5.5 mm.

As shown in FIG. 1, the main body A of the automatic torus ring automatic welding apparatus is detachably mounted on the spindle 1 screwed into the screw hole 102a of the water chamber lid 102. The schematic structure of the apparatus main body A will be described with reference to FIGS. 1 and 2. Reference numeral 2 denotes a circular mounting base that is screwed and fixed to the lower side of the support shaft 1. A rotating arm 4 that rotates is attached. Then, a copying stage 5 which can be displaced in the vertical and longitudinal directions (with respect to the groove center line of the welded portion a) is attached to one end of the rotary arm 4, and the welding torch 6 is attached to the copying stage 5. I'm wearing it. Further, a welding wire feeding device 8 for automatically feeding the welding wire W is attached to the rotary arm 4. Further, a welding position copying sensor 9 is also attached to the copying stage 5. This is because in order to keep the tip of the welding torch 6 and the welding location a during automatic welding in a predetermined positional relationship,
This is for learning a desired movement locus of the tip of the welding torch 6 being rotated around the support shaft 1. As for the welding torch 6, as a result of testing various types,
The TIG welder was found to be most suitable for the purposes of the present invention and was used.

Next, the detailed structure of the apparatus main body A will be sequentially described. The apparatus main body A can be divided into two parts: a mounting base 2 and a main body portion that is detachably connected to the lower side of the mounting base 2. The disk-shaped mounting base 2 is provided with a central shaft hole 2a. When the bolt 1a protruding from the bottom surface of the support shaft 1 is inserted into the central shaft hole 2a and the nut 10 screwed onto the bolt 1a is tightened, the mounting base 2 is horizontally fixed to the lower end of the support shaft 1. To be done. On the upper surface of the mounting base 2, three jack bolts 11 for leveling the same are erected in a triangular arrangement. A tilting leveling foot 11a is attached to the upper end of each jack bolt 11.

Reference numeral 20 is a circular intermediate disk which is detachably superposed on the lower side of the mounting base 2, and a ring gear 21 is formed on the peripheral edge thereof. Fixing claws 22 having fastening screws for fixing the circular intermediate plate 20 to the lower side of the mounting base 2 in a superposed state are respectively provided at three places on the upper surface of the circular intermediate plate 20 at equal intervals. It is provided.

On the lower surface of the circular intermediate disk 20, a cross roller bearing 23 having a diameter smaller than the diameter is concentrically attached. The rotary arm 4 uses the cross roller bearing 2
3 is fixed to the rotation side ring 23b. On one side surface of the rotating arm 4, a relay box 25 having a fitting 24 for supplying electric power, inert gas, air, water, etc., to the welding torch 6 is attached using a mounting bracket 26. ing. Also, height-adjustable supporting legs 27 are provided at three points on both ends of the rotating arm 4 and the lower surface of the circular intermediate plate 20 so as to support the device main body A at the time of storage or temporary placement. .

On the other side surface of the rotating arm 4, the assembly frame 31 of the rotating means 3 and the welding wire feeding device 8 are provided.
The assembling frames 32 are continuously connected via a connecting plate 33. The assembly frame 31 has a DC that constitutes the rotating means 3.
The servo motor 34 and its speed reducer 35 are assembled. Then, the pinion 3 axially fitted to the output shaft of the speed reducer 35
6 is engaged with the ring gear 21. A rotary encoder 37 for detecting the rotational position of the rotary arm 4 and a limit switch (not shown) for stopping the servo motor 34 are also attached to the assembly frame 31.

On the upper surface of one end of the rotary arm 4, a column 38 for mounting the copying stage 5 is provided upright. The copying stage 5 includes a front-rear copying stage 5A and an up-down copying stage 5B vertically assembled to the front-rear copying stage 5A.
It consists of and. Here, the front and rear mean front and rear toward the welding point a. Both copying stages 5A and 5B are
Each of them is a commercially available rectangular cylinder, and a DC servo motor for rotating the displacement screw rod, a rotary encoder for controlling the drive thereof, and the like are incorporated therein.

A welding torch 6 is attached to the upper and lower copying stage 5B.
A mounting position fine adjustment mount 40 for finely adjusting the tip position of the front and back and up and down by manual operation is attached via a bracket 41. The mounting position fine adjustment mount 40 includes a forward / backward moving unit 40A having a fine forward / backward adjustment knob 42 and a vertical movement unit 40B having a fine vertical adjustment knob 43.
The attachment member 7 of the welding torch 6 is attached to the vertical movement unit 40B.

As shown in FIG. 3, the mounting member 7 is provided with a mounting bracket 44 for the welding torch 6 and a holder 45 for holding a wire feeding portion of a welding wire feeding device 8 which will be described later. The holder 45 is provided with a fine adjustment mechanism (not shown) that finely adjusts the tip position of the wire to the front, rear, left, and right.

Further, a welding position copying sensor 9 is attached to the bracket 50 attached to the vertical copying stage 5B so that a contact ball (copying portion) 9a at the tip thereof can vibrate in the front and rear and up and down directions. . The contact ball 9a can be replaced with one having a different size according to the groove size of the V-cut groove-shaped welding portion a to be contacted. Reference numeral 51 shown in FIG. 2 is a swing cylinder of the position copying sensor 9, and when the copying operation is performed, the contact ball 9a is pressed into the V-cut groove of the welded portion a to be brought into contact therewith. Plays a role of separating the welded part a from the welded part a.

FIG. 4 shows the welding wire feeding device 8. A wire reel 62 is attached to the tip of a support arm 61 provided on the assembly frame 32, and a brake 63 and a knob 64 are attached to the reel shaft 62a. A feeding roller 65 sandwiches the welding wire W fed from the wire reel 62 and feeds it toward the welding position a. The rotational force of the driving DC servo motor 66 is transmitted to the roller shaft 65 a of the feeding roller 65 via the speed reducer 67. Welding wire W fed from feeding roller 65
Is guided through the guide sleeve 68 to the welding point a.

FIG. 5 is a wiring / piping system diagram of the entire automatic welding apparatus including the power source section and operation control section of the welding machine. 71
Is a main body portion of the TIG welding machine, 72 is an operation control unit of the automatic welding apparatus, 73 and 74 are connected to the operation control unit 72, respectively, and a portable operation box and an adjustment box for remotely controlling the operation of the apparatus main body A, Reference numeral 75 is a cooling water circulation pump for the welding machine. The operation surfaces of the operation box 73 and the adjustment box 74 are shown in FIGS. 6 and 7. Figure 8
[Fig. 4] is a partially enlarged cross-sectional view showing a state where welding at a welding location a has been completed.

Next, the operation of the above configuration will be described. In order to secure a sufficient welding strength, the welded part a has a first welding layer W1, a second welding layer W2, and a first welding third layer as shown in FIG.
We decided to sequentially weld in four welding layers of pass W3 and second pass W4. In this embodiment, the cut portion a of the torus ring 200 that is cut in the circumferential direction with the water chamber lid 102 fitted in the open lower end of the water chamber 101 of the high-pressure feed water heater that has been inspected and repaired. The gap width of the mating surface fluctuated considerably in the circumferential direction, and it was determined that the above-mentioned welding initial layer W1 was difficult to be satisfactorily welded by automatic welding in which the entire circumference is uniformly welded. Therefore, only the welding of the welding initial layer W1 was performed manually before the attachment of the apparatus main body A to the water chamber lid 102.

In order to attach the apparatus main body A to the lower side of the water chamber lid 102 and set it in the use state, first, the upper end side of the support shaft 1 is screwed into the shaft hole 102a of the water chamber lid 102. Next, the central shaft hole 2a of the mounting base 2 which is placed separately from the main body of the welding machine A in advance is inserted into the bolt 1a at the lower end of the support shaft 1. Then, each of the three jack bolts 11 is previously rotated and set to a predetermined length and placed, and the nut 10 is tightened while the leveling foot 11a is pressed against the lower surface of the water chamber lid 102. Is horizontally fixed to the lower end of the support shaft 1.

After that, the main body of the apparatus main body A is connected to the lower side of the mounting base 2. To do this, the fixing claw 22 provided on the circular intermediate plate 20 is rotated outward. , The main body is placed on a simple lifter with wheels (not shown), and moved to the lower side of the mounting base 2. Then, the lifter is moved upward so that the circular intermediate plate 20 is concentrically overlapped with the lower side of the mounting base 2, and each fixing claw 22 is turned inward to tighten the fastening screw. The work of mounting the device main body A on the lower side is easily completed.

Next, as described above, the operation of learning the desired movement locus of the tip of the welding torch 6 attached to the rotary arm 4 is carried out prior to the automatic welding of the welded portion a divided into three layers in sequence. To do. To do this, start the SW of the welding equipment
Then, by operating the copying stage 5 and the mounting position fine adjustment mount 40, the welding position copying sensor 9 is brought to a predetermined relational position with respect to the V-cut groove at the welding point a after the first layer welding. Set so that After that, when the teaching SW is pushed by the operation box 73, the welding position copying sensor 9 which is normally in the standby position separated from the welding position a is moved by the swinging cylinder 51 to the operating position shown in FIG. The contact ball 9a is pushed into the V-cut groove of the welded portion a and comes into contact with the groove wall by vibrating the neck toward. Then, the rotating means 3 rotates the rotating arm 4 once,
In the meantime, the welding position scanning sensor 9 continuously detects a change in the position of the contact ball 9a with respect to the weld groove center line before and after, and a change in the vertical position with respect to the weld groove center line, and this change is detected. The signal is input to the memory circuit provided in the operation control unit 72. This teaching is a torus ring 20
It is also possible to perform it only on an arbitrary part of the entire circumference of 0.

After finishing the teaching, the copying stage 5
And the mounting position fine adjustment mount 40 is operated to set the welding torch 6 at a position suitable for welding the second layer, and the rotation speed of the rotating arm 4 is set by the operation control unit 72, the operation box 73 and the adjustment box 74. After setting the welding conditions such as the feeding speed of the welding wire W and the welding current, and pressing the playback SW, the welding torch 6 rotated together with the rotating arm 4 is moved by the teaching and stored in the operation control section 72. Following the locus, the welding second layer W2 is automatically welded.

Next, the process proceeds to automatic welding of the first pass W3 of three layers of welding. In this case, the tip of the welding torch 6 and the welding point a.
As will be understood from FIG. 8, the positional relationship with
It is slightly offset from 2 in the front-back and up-down directions. So 2
By the same operation as the first layer, set the position of the welding torch 6 to a position suitable for welding the first pass W3 of the third layer, set the welding conditions, and press the playback SW The welding of the first pass W3 of (1) automatically proceeds. The welding of the second pass W4 of the three-layer welding can be automatically performed in the same manner as the first pass.

In the automatic welding of the welding layers W2 to W4, as described above, the position of the welding torch 6 is set to the position suitable for the welding of the respective layers obtained in the prior welding test before starting the welding. Once set, the automatic welding is performed by playing back the position change of the V-cut groove at the welding point a stored by teaching, so that the position of the welding torch 6 during welding starts welding by the copying stage 5. It can be automatically held in the relevant position set for the previously set welding. In addition, looking at the finish of welding during automatic welding,
When it is desired to correct the position of the welding torch 6, this can be easily done by operating the operation box 73 or the adjustment adjustment knobs 42 and 43, and the welding conditions can also be corrected by operating the adjustment box 74.

[0025]

As is apparent from the above description, the automatic torus ring welding apparatus for a high-pressure feed water heater according to the present invention has various excellent effects as listed below, as compared with the conventional welding work relying on manual labor. Play. (A) It is relieved from the tight welding work that is performed by bending down in a narrow space. (B) Therefore, it is possible to eliminate the risk that the welding state will unknowingly become poor due to the work in this unnatural posture. (C) Therefore, when a defective welding portion is found by the finish inspection, extra trouble and cost for correcting the defective portion can be largely saved. (D) Further, even a person who is not a particular expert can perform reliable welding, and can deal with the problem of shortage of skilled operators expected in the future.

[Brief description of drawings]

FIG. 1 is a partial vertical cross-sectional side view showing an embodiment of the present invention with a device body attached to a water chamber lid.

FIG. 2 is a partial bottom view of the same as the above.

FIG. 3 is a front view of a portion where a welding torch and a welding position copying sensor are attached to the copying stage.

FIG. 4 is a plan view of the wire feeding device of the above.

FIG. 5 is a wiring / piping system diagram of the entire automatic welding apparatus including a power supply section of the apparatus body, an operation control section, and the like.

FIG. 6 is a plan view of an operation box of the automatic welding machine.

FIG. 7 is a plan view of the adjustment box of the automatic welding machine.

FIG. 8 is an enlarged vertical cross-sectional view of a welded portion of the torus ring of the above.

FIG. 9 is a partial vertical sectional view of a high-pressure feed water heater.

FIG. 10 is a partially enlarged view of the same as above.

FIG. 11 is a sectional view taken along line XX of FIG.

FIG. 12 is a reference view showing a conventional technique, and is a perspective view showing a state in which a torus ring is cut.

FIG. 13 is an enlarged vertical sectional view showing a cut portion of the above.

FIG. 14 is an enlarged view showing a cut state of the torus ring 200 in the above.

[Explanation of symbols]

 A device body 1 support shaft 1a bolt 2 mounting base 2a center shaft hole 3 rotating means 4 rotating arm 5 scanning stage 5A front-back scanning stage 5B vertical scanning stage 6 welding torch 7 mounting member 8 welding wire feeding device 9 welding position scanning sensor 9a Contact ball 10 Nut 11 Jack bolt 11a Leveling foot 20 Circular intermediate plate 20a Center hole 21 Ring gear 22 Fixed claw 23 Cross roller bearing 23a Fixed side ring 23b Rotating side ring 24 Wiring / Piping joints 25 Relay box 26 Mounting bracket 27 Supporting leg 30 connecting plate 31, 32 assembly frame 33 connecting plate 34 DC servo motor 35 reducer 36 pinion 37 rotary encoder 38 support post 40 fine adjustment mount for mounting 40A forward / backward movement unit 40B vertical movement unit 41 bracketing 42 Vertical fine adjustment knob 43 Vertical fine adjustment knob 44 Mounting bracket 45 Holding tool 50 Bracket 51 Swing cylinder 61 Support arm 62 Wire reel 63 Brake 64 Pick 65 Feed roller 66 DC servo motor 67 Reducer 68 Guide sleeve 71 Welding Machine body 72 Operation control unit 73 Operation box 74 Adjustment box 75 Cooling water circulation pump 100 High-pressure water heater 101 Water chamber 102 Water chamber lid 102a Screw hole 200 Torus ring W Welding wire a Welding point g Gap W1 Welding first layer W2 Welding 2nd layer W3 3rd welding first pass W4 3rd welding second pass

Claims (2)

[Claims] 1. A cylindrical water chamber 1 constituting a high-pressure feed water heater.
The torus ring 200 having a substantially C-shaped cross section, which is welded across the gap for fitting the fitting gap of the water chamber lid 102 fitted to the open lower end of 01, is pressure-checked. In order to remove the water chamber lid 102 after each repair, the water chamber lid 102 is temporarily cut in the circumferential direction, but the device of the present invention attaches the water chamber lid 102 after the inspection / repair and then welds the cut portion. A mounting base 2 which is detachably hung vertically in a supporting shaft 1 projecting from the center of the lower surface side of the water chamber lid 102, and is attached to the mounting base 2 to rotate. A rotary arm 4 which is horizontally rotated around the support shaft 1 by means 3, and a rotary arm 4 attached to the rotary arm 4 toward the welding point a with reference to the center line of the weld groove. A copying stage 5 that can be displaced in the up-down direction and the front-back direction, and a combination of the copying stage 5 The welding torch 6 attached, the welding wire feeding device 8 attached to the rotating arm 4, the tip of the welding torch 6 rotated together with the rotating arm 4, and the welding portion a have a predetermined positional relationship. In order to hold the welding stage 5 and the copying stage 5 attached to the copying stage 5 for learning a desired movement trajectory of the tip of the welding torch 6 during automatic welding, and the copying stage 5 during automatic welding. A turbine high-pressure feed water heater, which is provided with an operation control section 72 for causing displacement movement based on learning information of the welding position scanning sensor 9 and automatically advancing a series of welding operations according to an operation program arbitrarily set. Torus ring automatic welding equipment. 2. The fixed base ring 23a of the ring gear 21 and the cross roller bearing 23 is mounted on the mounting base 2.
Are respectively attached concentrically to the support shaft 1, the rotary arm 4 and the rotating means 3 are assembled to the rotating side ring 23b of the cross roller bearing 23, and the rotating means 3 rotates them. The automatic torus ring welding device for a turbine high-pressure feed water heater according to claim 1, wherein the pinion 36 to be engaged is meshed with the ring gear 21.