JPS62264831A - Manufacture for turbine wheel - Google Patents

Abstract

PURPOSE:To enable the unevenness of machining accuracy to be prevented by providing a scooped piece, which is obtained by hollowing a blade implanting groove, serving for a blade root and welding a blade part to said blade root by electron beam welding thereafter fitting said blade root to the blade implanting groove. CONSTITUTION:First a blade implanting groove is hollowed to be formed in the peripheral edge part of a rotor disc 7 by wire cut electric discharge machining, and a scooped piece, which is obtained by hollowing the blade implanting groove, is used serving for a blade root Br. And a separately molded blade part Bl is welded to said blade root Br by electron beam welding. This electron beam welding device comprises an electron generating chamber 100, beam inducing path 200, welding work chamber 300, welding work moving table 400, vacuum exhaust means 500, control unit 600 and a high voltage power source 700. A turbine wheel is manufactured by fitting the blade root Br of a blade, integrally formed by said electron beam welding, to the blade implanting groove of the rotor disc.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a rational manufacturing method for a side-entry single-type impeller used in a turbine, turbocharger, fan, or the like.

<Prior Art> Conventionally, as shown in FIG. 13, a method for manufacturing a turbine blade wheel involves creating a rotor R in which a plurality of rotor disks D, D2 are integrally formed, and each of the rotor disks D,
, D2, the Rm groove S is formed by the milling cutters 01 to 05 attached to the workpiece 111[M, and as shown in FIGS. 15 and 16, this [! A blade B having a blade root Br machined by milling cutters 011 to 015 from a material m into a shape that fits into the groove S is created, and as shown in FIG. 17, the blade root Br of each RB is attached to a rotor disk D, 3! I am trying to integrate it by fitting it into the plant Is.

In general, rotors that are rotated at high speed in an atmosphere of 510°C or higher are manufactured by adding elements such as nickel, chromium, molybdenum, and vanadium to the material.
In order to obtain a perfect structure by reducing the influence of ass effect), a heat-treated strong steel is used that is resistant to softening during tempering, has creep resistance, high tensile strength, and high toughness, and its specific cutting force is f = 0.2 m
The machinability ratio is 40 or less at m/rev of 300 kg/mrn' or more.

Furthermore, in recent years, there has been a trend toward the use of heat-resistant nickel alloys in rotors used at even higher pressures.

<Problems to be solved by the invention> The rotor disk D1 as shown in FIG. 13 has poor machinability.
．． The wing set 4s to be formed on D2 is made using a grooving milling cutter 01,
m-bottom rough milling cutter 02, serration rough milling cutter 03, serration medium finishing milling cutter 04, finishing overall shape milling cutter 05
They are replaced in this order, and cutting is performed using the machine tool wtM while feeding from right to left in Fig. 14. Milling cutter 01~
A broach can be considered as a tool other than 05, but if the outer diameters of the rotor disks DI and D2 and the positions of the blade grooves S are different from each other, adjacent rotor disks will interfere and cannot be used. Even if the broach does not interfere, an expensive broaching tool is required for each different groove size and groove shape.

On the other hand, the material gB shown in Figs. 14 and 15 also has the strength to withstand centrifugal force and steam thrust vibration, as well as its creep limit not decreasing even at high temperatures, and its corrosion resistance and erosion resistance against moisture impurities. It is necessary to meet certain conditions, and furthermore, it is necessary to satisfy conditions such as good damping performance. Therefore, when used in high-temperature conditions, 12-13% chromium steel (martensitic stainless steel) with elements such as molybdenum and tungsten is used, but especially in stages with severe steam conditions, a large amount of nickel is used. There is a trend toward using austenitic stainless steels, including Inconel and even Monel, in gB, which requires high-temperature strength and greater resistance to corrosion and abrasion from superheated steam. The blade root Br of this gB is also processed by milling or broaching, and in the case of milling, a slope milling cutter 011, a first stage milling cutter 012, a second stage milling cutter 013, and a serration rough boring milling tool are used. 014, the serration finishing cutter and milling cutter 015 are sequentially replaced during processing. However, since austenitic stainless steel has a metastable austenitic structure, part of it becomes martensitic during processing, resulting in severe work hardening, and the work hardening caused by the preceding cutting edge increases the specific cutting force against the next cutting edge. It ends up.

The blade root Br of the blade B that has been extruded as described above is inserted into the blade root groove S of the rotor disk D, D2, which was cut in the separate process, from the side as shown in Fig. 16. implanted.

As shown in Figure 17, which shows the fitting distance, the BP surfaces should be in contact with each other, and the other surfaces should be in contact with each other by 0.2 mm to 0.4 mm.
Provide a gap PRA about the size of the torso.

This is designed to support the centrifugal force of the blade B with the compressive stress of many BP surfaces, and the failure of the neck N of the blade can be prevented by the neck N.
This is prevented by the tensile stress in the part and the compressive stress in the BP surface in the part wider than that part. When each BP surface is uniformly hit, the resistance to breakage is the same at every neck N, and the aim is for the resistance to be equal to the resistance at the widest neck N. Therefore, , BP surfaces are required to have uniform contact conditions at all locations during operation.

Therefore, when assembling, the fitting gaps between each part should be determined in consideration of thermal expansion, etc.
As BP<BF<PRA, BP surface part is ±0013 cylinder, B
The F plane part is within the minute tolerance of ±005 cylinder. In order to achieve this tolerance, it is necessary to finish the blade root Br of the blade and the blade root groove S of the rotor R using a limit gauge and carefully checking each of the above-mentioned separate cutting processes.

Furthermore, as far as cutting is concerned, it is inevitable that curvature will occur at the cutting end of both the 'RNi groove S and the blade root Br, making chamfering necessary.

As described above, the conventional method for manufacturing a blade wheel has various problems as described below.

(1) The rotor material has poor machinability and the blade grooves are difficult to hollow out, but this requires a large amount of man-hours and construction time because it is done by cutting.

(21 (For the same reason as 11, only a small depth of cut can be obtained, so many types of tools are required, and the tool wear is severe in the paper.

(3) The blade material has poor machinability, and only a small depth of cut can be obtained at the blade root, requiring many types of tools and requiring a large number of man-hours.

(4) Since only a small depth of cut can be obtained from the blade root, work hardening occurs and the specific cutting force increases.

(5) Since both the N groove and the blade root are made by cutting,
In any case of cutting, a strong fixed acid (or holding means) is required for the workpiece and cutting tool to support the cutting resistance.

(6) Tool path error during cutting directly affects the fitting gap size with the IiN groove blade root.

(7) Since the blade root is cut out from the same material as the blade part, a lot of chips are discharged, a large amount of expensive blade material is required, and the material yield is poor.

(8) N-groove and blade root 1: Because it is necessary to combine the pieces cut in separate processes and fit them together within minute fitting tolerances, the machining of the N-groove and the blade root each have their limits. It is necessary to finish with high precision using a gauge.

(Both the 91N planting groove and the blade root are curled due to cutting, and a chamfering process is required.

It is an object of the present invention to provide a method for manufacturing a blade wheel that solves these various problems.

Means for Solving the Problems> The method for manufacturing a blade wheel according to the present invention is to form N grooves in the peripheral edge of a rotor disk by wire cut electrical discharge machining, and to obtain the N grooves by punching the N grooves. The hollowed-out piece is used as a blade root, and a separately formed blade part is welded to this blade root by electron beam welding, thereby fitting the blade root of the integrally formed blade into the N groove of the rotor disk. It is characterized by the following.

Function: Since the blade root is fitted into the corresponding N groove that has been cut out, the wire diameter and second cut offset amount must be properly adjusted in advance during wire cut electrical discharge machining, and the required gap must be drilled. If this is done, after the blade is completed, the desired fitting relationship can be obtained by shifting the blade toward the tip side and fitting it. In this case, a slight error in the wire path at the time of hollowing out the blade root does not affect the precision of the fitting gap, although it may affect the fitting position.

On the other hand, if the electron beam welding joint surface between the blade root and the blade section is made parallel to the tangential direction of the shaft rotation passing through the shelf of the blade root light, the joint area can be maximized, and the joint surface will work radially outward due to the rotation of the blade wheel. Tensile stress caused by centrifugal force is minimized. Therefore, even if there is a slight welding defect, there is no risk of breakage.

Embodiment One embodiment of the present invention is shown in FIGS. 1 to 12, and the method for manufacturing a blade wheel according to this embodiment is to manufacture a turbine rotor using a wire-cut electrical discharge machining apparatus shown in FIGS. 1 to 5. From the rotor disk D2 of R to the blade root Br as shown in FIGS.
The hollowed-out blade root Br is joined to the blade part Bl as shown in FIG. 9, and the joined part is welded using the electron beam welding device shown in FIG.
A second step of forming gB as shown in Fig. 2, and fitting it to the hollowed out N groove S of the rotor disk D2 by shifting it radially outward by the dimension T3 as shown in Fig. 7. It consists of a third step. Note that, if necessary, a correction grinding process may be inserted between the second process and the third process.

The electric discharge machining device used for the first process includes a machine body 1 and a 1117
The machine is comprised of an NC device 7 that performs the following steps, and a processing power source 8 that supplies pulses between the machining holes. The machine body 1 includes an annular work table 2 rotatably supporting an indexing table 21 on which the turbine rotor R is vertically mounted and rotatably indexed;
A base 30 is integrated with the work table 2 and has three columns 3 erected thereon, and a base 30 is fitted to the columns 3 so as to be slidable in the vertical direction (hereinafter simply referred to as the vertical direction) in FIG. a cross slide 5 that is slidably guided in the vertical direction (hereinafter referred to as the horizontal direction) in FIG. 2 on this saddle 4; A slide head 6 that is slidably guided in the middle, left and right directions (hereinafter referred to as the front and rear directions) and is equipped with a wire guide means, a wire electrode supply drum 11, a wire electrode winding drum 13, Processing fluid supply device 15
It consists of Furthermore, in order to smoothly control the feed speeds of the cross slide 5 in the horizontal direction and the slide head 6 in the front and rear directions, which are extremely slow compared to general machine tools, a roller support system is adopted for each feed guide. has been done.

The annular work table 2 is installed on the floor 20 concentrically with respect to a pit 22 formed in the floor 20, and the shaft end of the turbine rotor R can pass through the center of the pit 22. A cylindrical indexing table 21 is rotatably supported concentrically. Two sets of gripping claws 22 a guided to the horizontal guide hole 23 of the indexing table 21 are provided facing each other so as to grip the journal portion of the turbine rotor R at the center of the work table 2 . The front end of the gripping claw 22alC is threaded, the middle part thereof is pivotally supported by the cylindrical part of the indexing table 21 via a thrust bearing 25, and the small end thereof is provided with a hole for engaging a rotating wrench. . Further, a worm wheel 26 externally fitted and fixed to the indexing table 21 is engaged with a worm 28 rotated by an indexing motor 27 provided on the work table 2, and a plate 31 fixed to the tops of the three columns 3 A vertical movement motor 32 is attached to the. The vertical feed screw 33 rotated by the vertical movement motor 32 is screwed into a female collar 41 fixed to the saddle 4, and its lower end is connected to the base 30.
It is pivoted on. The guide @42 is fixed to the saddle 4 and slidably fitted onto each of the three columns 3, and the left-right direction feed servo motor 43 is attached to the side surface of the saddle 4. This left and right direction feed servo motor 4
A ball screw shaft 44 that rotates at the same time as shown in FIG. The guide roller 55 supports the cross slide 5 on the guide surface on the upper surface of the saddle 4.
A longitudinal feed ball screw shaft 54 rotated by a longitudinal feed servo motor 53 attached to an end face of the slide head 6 is screwed into a pole nut (not shown) fixed within the slide head 6. Further, the slide head 6 is guided on the upper surface of the cross slide 5 so as to be slidable in the front and back direction via guide rollers in the same manner as described above, and is equipped with wire guide means. Then, the wire electrode 60 is connected to the rotor disk D2.
An upper support arm 63 and a lower support arm 64 to which wire guides 61 and 62, which are supported above and below, are attached, protrude in the front-rear direction. This lower support arm 64 is fixed to the slide head 6, but the upper support arm 64 is fixed to the slide head 6.
3 is adjustable so that it can be moved up and down, and the adjustment range is set to about 80 mm in this embodiment. This is to place the support point of the wire electrode 60 as close to the rotor disk D2 as possible, and to process the wire electrode 60 in a manner that prevents the wire electrode 60 from wobbling or the like.

A wire guide 61 forming part of the wire guide means,
62 has a fan-shaped structure made of wear-resistant sapphire, as shown in FIG. This is because the wire electrode 60 is bent with a large curvature and guided to the processing location 50, which will be described later, because if a sudden strain is applied to the wire electrode 60, the wire electrode 60 may be twisted or otherwise distorted, which may have an adverse effect on processing accuracy. Other wire guide means include a feed reel 45, a tension roller 47, a rubber roller 48, a disconnection detection roller 49, a presser roller 65, a winding roller 66, a winding roller 69, and guide rollers each provided as an idler in the middle thereof. 46.degree. 56.57 and 67.68 are both supported by shafts horizontal to the side surface of the slide head 6, but it is necessary that they rotate evenly and have excellent roundness. Further, the guide roller 58 is pivotally supported by an upper support arm 63. In addition, other members attached to the slide head 6 include a rubber presser release lever 34, an upper support arm vertical adjustment knob 37, and an upper support arm clamp lever.
38 and an energizing pin 35, which is connected to one terminal of the pulse generator shown in FIG. The wire electrode 60 is made of brass, and has excellent machining efficiency and blade root Br and N.
In consideration of the gap with the pole groove S and the trouble of wire breakage, a wire with a diameter of 0.15 mm is used in this embodiment. The wire electrode 60 wound around the feed reel 45 is guided by a guide roller 46 and a required tension is applied by a tensile roller 47. 61 and guide roller 58 in order, the wire is wound up by a winding roller 66, and further passes through guide rollers 67 and 68 and is wound onto a winding reel 69, but the wire guide 6
The vertically extending portion between 1 and 62 becomes the processing location 50. Disconnection detection rollers 49 and 59 are installed in the middle of these to detect disconnection of the wire electrode 60, and at the same time as the disconnection occurs, the 'J2 switch is activated and the processing power is turned off.
It has a mechanism that stops the drive.

The guide roller 12 guides the wire electrode 60 from the supply drum 11 storing the wire electrode 60 to be supplied to the wire guide means to the feed reel 45, and conversely, the guide roller 14 guides the wire electrode 60 to the take-up roller 6 of the wire guide means.
9 is a guide roller to the winding drum 13 that stores the used wire electrode 60 from the winding drum 13.

The machining fluid supply device 15 includes a machining fluid tank 16 containing a deionizer using ion exchange resin, a pump 17, a nozzle 19 that supplies machining fluid 10 to a machining location 50, and a flexible structure that connects these. It consists of a tube. The machining fluid receiver pan 18 is connected to the machining fluid tank 16 via a flexible pipe.
The processing liquid 10 is ion-exchanged water.

The machining power supply 8 that supplies pulses between the energizing bottle 35 and the contact 83 of the rotor disk D2 is a capacitor discharge circuit using a transistor 81 as shown in FIG. The pulses supplied between these contacts 83 have a limit on the current value flowing through the wire electrode 60, and the average current is IO.
A, a discharge pulse waveform condition with high machining efficiency is required even with the same current, which requires the use of a pulse with a narrow pulse width and a high current peak value. Therefore, in a transistor switching circuit, capacitor 8
2 is inserted between the poles.

As shown in FIG. 5, the NC device 7 controls the left-right feed servo motor 43 that moves the cross slide 5 of the 8B machine body 1 in the left-right direction, and the back-and-forth feed servo motor 53 that moves the slide head 6 in the front-back direction. Program information data representing the movement (cutting path) of the processing area 50 where the wire electrode 60 at the tip of the slide head 6 is stretched vertically (processed by the controller 91, which is a calculator).The controller 91 performs the first interpolation. The output of the first interpolator 92 controls the servo motors 43, 53r, !1 through the second interpolator 93, and moves the four slides 5 in the left and right direction, and also controls the slide head 6. The first interpolator 92 receives pulses supplied from an oscillator 94, and the output frequency of the oscillator 94 is determined by a frequency multiplier under the control of a comparator circuit 95. 96. The comparator circuit 95 then generates a signal which is a function of the difference between the magnitude representing the state of machining or discharge quality and the magnitude representing the reference value in a known manner.

To explain the first step of hollowing out the blade root Br from the rotor disk D2 of the turbine rotor R using the above-mentioned device as shown in FIGS. Install the turbine rotor R
The shaft end passes through the indexing table 21 and the bit 22 of the annular work table 2, and the side end surface of the rotor disk D is supported by the upper end surface of the indexing table 21, so that the turbine rotor R is vertically stabilized. do. The gripping claws 22a serve both for centering and gripping the journal portion of the turbine rotor R. That is, by rotating the threaded rod 24 in the forward direction by a rotating means (not shown), the gripping claw 22a moves toward the center in the front-rear direction, and by contacting the journal portion with its V-block-shaped tip, the turbine The rotor R is located at the center position in the left-right direction. At the same time, the threaded rod 24
The turbine rotor R is gripped at the center of the indexing table 21 by adjusting the positive rotation amount to the same amount.

To set the machining location 50 of the wire electrode 60 at the height of the rotor disk D2 to be machined of the turbine rotor R as shown in FIG. 33 and female thread 41
The saddle 4 is moved and adjusted in the vertical direction through the three columns 3, and then the saddle 4 is clamped to the three columns 3.

At this time, the three columns 3 vertically guide the saddle 4 and provide stable support. Furthermore, the vertical adjustment knob 37
to adjust the position of the upper support arm 63 to the rotor disk D.
The upper support arm clamp lever 38 is tightened to clamp the upper support arm.

The horizontal position of the processing location 50 of the wire electrode 60 should also be placed at the machine origin. The wire K S 60 includes:
In this embodiment, a constant tension of approximately 800 g is applied by the tensian roller 47, and this is to minimize forced vibration due to discharge repulsion force. In this way, 9! is applied in the longitudinal direction while 1 ton of tension is applied without fluctuation! The machining point 50 of the continuously displaced wire electrode 60 is sent along a preprogrammed cutting path from the machine origin, and at the same time the cross slide 5 is controlled in the left and right direction by the servo motor 43. This is done by controlling the slide head 6 in the front-back direction and moving the wire guides 61 and 62. 80 from the machine origin to the position of the machining origin 84 in Figure 6.
The machining location 50 of the wire electrode 60, which has been positioned at a rapid feed rate of about 0 m/min, is now switched to the machining feed speed, approaches the rotor disk D2, and is cut along the shape of the stud while generating electric discharge. , gap G
Cut out using the second cut method. That is, in FIG. 6, a first cut is made along the outer shape of the blade root Br up to the RP point as indicated by the dashed-dotted line arrow 85 with an offset amount of H and a feed rate of f, mm/min, and from this RP point H2 Fold back as shown by the two-dot chain arrow 86 at f2mm/min, which is the offset amount of f and the feed rate of about 4@, and! fa groove S.

A second cut is made along the line up to the processing origin 84. Here, in the first cut, the offset amount H1 is the radius of the wire electrode 60, and no finishing allowance is left on the outside of the blade root Br. In the second cut that is turned back from the RP point, the electrical processing conditions are weakly adjusted in order to improve the finished surface accuracy and roughness. For example, from the RP point to the Bf section, send the same route as the first cut in the opposite direction, and at the neck N of RB (
By setting the offset tH2 as the radius of the wire electrode 60 and leaving no finishing allowance on the inside of the blade groove S, the desired gap P RA' shown in FIG. 7 is obtained (T, sin θ') m
The path is controlled to create a narrow gap G' by m. Following this (the BP surface area is sent in the opposite direction as in the first cut, and the neck N' of the rotor disk D2 is
Similarly to the area of the neck N, control is performed once. Next, in the gap PRA section shown in FIG. 7, a gap G narrower than the desired gap PRA by T tan θ is created. ! control on the road.

Furthermore, the groove bottom Bt portion controls the feed to a path that creates a narrow gap G' by the desired gap BtA and T3. In this way, the electric discharge machining continues to return to the machining origin 84, but during this time the machining fluid 10 is injected from the nozzle 19 shown in FIG. 1 toward the machining location 50 of the wire Tit' 560.

Thereafter, the position of the wire electrode S is moved to the next machining origin 84' by rotating the Kupin rotor R in the circumferential direction by one pitch of the N-groove S. This indexing rotation is performed by controlling the rotation of the indexing motor 27 to rotate the worm 28, the worm wheel 26, and the indexing table 21.
Do it through.

Here, a hand 99 of a known robot (not shown) attached to the saddle 4 grips the blade root Br from both upper and lower surfaces as shown in FIG. Then, the wire electrode 60 that has reached the machining origin 84' discharge-cuts the adjacent blade implant II4S again along the blade implant shape in the same manner as described above (however, after passing the RP point, the hand 99 cuts the blade root Br. Take it out vertically as shown in Figure 8 and place it on a pallet (not shown) to be transferred to the next second process.

Thereafter, the blade roots Br are hollowed out in the same manner and arranged in order on the pallet so that the combination with the blade groove S can be determined.

The roughness of the machined surface is greatly improved by the second cut, and no warping occurs on the machined end face of either the blade root groove S or the blade root Br. Therefore, the pallets in which the blade roots Br are lined up in order are sent as they are to the next second process.

As shown in FIGS. 10 and 11, the electron beam welding apparatus used in the second step includes an electron generation chamber 100, a beam guide path 200, a welding work chamber 300, a welding workpiece moving table 400, and a vacuum evacuation means. 500 and control device @600
and a high voltage power supply 700.

The electron generation chamber 100 includes an electron gun 101, a tungsten cathode 3103, and an anode 104 made of stainless steel.
and a lattice 102 that functions in the same way as a grid, and the one designated by the reference numeral 105 is a hinge.

In addition, the beam guiding #5200f is equipped with a condensing lens 201 and a polarizing coil 202, which minimizes the diffusion of the electron beam flow (and allows it to reach the joint between 8BI and the blade root Br). In the figure, 203 is an alignment adjustment valve, 204 is a column valve, 205 is a vent valve, and 206 is an observation microscope. It is connected to a pump, and an opening 303 is formed at the bottom of the vacuum chamber 302 through which the joint between the blade Bl and the blade root Br attached to the mounting jig J can be seen. Reference numeral 304 indicates a viewing window, and reference numeral 305 indicates a water-cooled heat shielding plate.Furthermore, the welding workpiece moving table 400 includes a continuous welding rotary table 402 having a number of concentric pockets 401 for storing mounting jigs J; It consists of a saddle 405 that can be freely carried and slidable in the front-back direction, and a control device 6 for moving and rotating in the front-back direction.
Controlled by 00. The evacuation means 500 includes an electron gun exhaust system including a diffusion pump 501 and an oil rotary pump 502 connected to the electron generation chamber 100, and a diffusion pump 5.
10, mechanical booster 511, and oil rotary pump 51
Welding room vacuum exhaust system including 2 and the first stage exhaust port 521
a.

521b and second stage exhaust ports 522a and 522b. Welding work room 300
The gap C between ring-shaped sealing materials 524 and 525, which are arranged in the circumferential direction of the upper surface of the welding rotary table 402 and eliminate leakage in the radial direction, is a region that is evacuated to vacuum in stages. Yes, the code in the figure is 527a.

527 b+! A ply for suppressing the inflow of air before and after the exhaust; a ζ ring 530 is a cooling water supply means.

In the first step, as shown in FIG. 8, the blade root Br hollowed out from the rotor disk D and the blade part Bl manufactured in a separate process are butted together as shown in FIG. 9, and the electronic In the second step of beam welding, first, as shown in FIGS. 10 and 11, at the attachment/detachment station St of the welding rotary table 402, the mounting jig J in which the blade portion Bl and the blade root Br are set is placed inside the bulge I-401. Store it in. Since the welding rotary table 402 is continuously rotating, the mounting jig J
The pocket 401 that stores the slide ring 527a
The air is blocked by passing under the first stage exhaust ports 521a and 522a, and the degree of vacuum is gradually increased from a low vacuum by passing under the first stage exhaust ports 521a and 522a, and the vacuum level is gradually increased to reach the opening 303 at the bottom of the vacuum chamber 302. At that time, the same degree of vacuum as the vacuum chamber 302 evacuated by the diffusion pump 510 is reached. On the other hand, electrons are emitted from the tungsten cathode 103, and a voltage of about 80 KV is applied between the tungsten cathode 103 and the anode 104. Electrons emitted from the tungsten cathode 103 (accelerated by the generated electric field,
The grating 102 is O~16 with respect to the tungsten cathode 103.
Since a voltage up to 0 V can be freely applied, the amount of hot electrons from the tungsten negative ji 103 can be freely adjusted. These thermionic currents are focused by a focusing lens 201 in the beam guide path 200, and are correctly irradiated onto the joint surface between the blade portion Bl and the blade root Br. In this way, the blade part Bj and the blade root B
r is electron beam welded to form X(
B is formed. In this case, the electron beam welded joint surface is
This is the widest surface of the blade section parallel to the cutting line direction passing through the shelf sh of the blade root light, and high tensile strength can be obtained.

Welding accuracy is achieved because the blade portion Bl and blade root Br are restrained by the mounting jig J, and because only 4% of the energy heat input is required compared to TIG welding, thermal deformation is small. However, if necessary, partial correction grinding may be performed to correct accuracy at this stage. In addition, in this second process, similarly to the first process, the blades B are arranged in order on a pallet (not shown) and transferred to the next third process.

In this third step, the rotor disk D of the turbine rotor R has already been machined with the R groove S in the first step, and the above-mentioned reversal has not occurred, so it is directly attached to the blade ins.
Insert them one by one. Then, the bottom of each gB and g groove S
Temporarily insert a shim so that there is a gap between BtA and BtA shown in FIG. 7. As a result, the BP surfaces come into contact with each other, and the other surfaces have a gap PRA of about 0.2 to 0.4 threshold.
Can be done. Even if the shim is removed and the operation is started after tenon tightening is applied to the 311B, the entire IBP surface (due to centrifugal force) can be in uniform contact.

<Effects of the Invention> According to the manufacturing method of the 'R car of the present invention, the blade grooves and blade roots of the rotor disk are cut into the desired shape by wire-cut electric discharge machining, so the material is made of a material that is difficult to hollow out and can be used for KM or lithography. Even tree-like machining shapes can be processed by awL without requiring many tools.

Moreover, there is no work hardening that occurs in multi-step cutting, and the process can be done in a short time. Also, from the rotor disk, the 'R [groove was cut out, and the Q
l') Since a thick piece is used as the blade root, machining errors can be kept constant by adjusting the wire diameter and second cut offset, making it easy to prevent variations in machining accuracy, and with less cutting chips. All the problems of conventional methods can be solved, such as the yield of expensive materials being significantly improved. In addition to this, there are the following effects.

(In wire-cut electrical discharge machining of 11R planting grooves, there is little cutting force, so there is no need for a workpiece clamp.

(2) Processing can be performed regardless of the hardness of the workpiece.

(3) Since neither the blade roots nor the N grooves curl, a chamfering device is not required.

(4) Wire-cut electrical discharge machining for blade grooves is easily adaptable to automation, allowing unmanned operation day and night.

(5) By making the electron beam welding equipment a staged exhaust type, the vacuum chamber can be made smaller and the evacuation time can be shortened.

(6) Compared to the method in which the blades are directly electron beam welded to the rotor, only the blades are electron beam welded within the chamber, so the vacuum chamber can be smaller.

[Brief explanation of drawings]

Fig. 1 is a partial sectional view of an example of a wire-cut electrical discharge machining apparatus used in an embodiment according to the present invention, and Fig. 2 is a partial cross-sectional view of an example of the wire-cut electric discharge machining apparatus used in one embodiment of the present invention.
3 is a conceptual diagram of the mechanism of the wire guide means of the slide head, FIG. 4 is a discharge circuit diagram thereof, and FIG. 5 is a block diagram of the NC unit that controls the servo motor.
Figure 6 is a machining principle diagram showing the state of wire-cut electric discharge machining of the rotor disk. Figure 7 is a partially enlarged view of the fitted state between the blade root and the blade groove. Figure 8 is a diagram showing the blade root being controlled from the rotor disk. FIG. 9 is a perspective view showing the state in which the blade root and the blade part are joined together; FIG. 10 is a sectional view showing the structure of an example of an electron beam welding device; FIG. XI-XI
12 is a perspective view of the welded state of the blade part and the blade root, FIG. 13 is a perspective view showing the processing principle of the blade groove of a conventional rotor disk, and FIG. 14 is a conventional blade root. FIG. 15 is a conceptual diagram of the machining process showing the positional relationship between the workpiece and each milling cutter at this time. FIG. 17
The figure is an enlarged view of the fitting portion. Also, in the figures, R is the turbine rotor, and D is the symbol R. D2 is a rotor disk, S1. f″ii N R, B
is the wing, Br is the g root, and Bl is the wing. Figure 3 Figure 4 Figure 5 Section 2, -□-1 Figure 8 Figure 9 Figure 11 Figure 16 Figure 17

Claims (1)

[Claims] A blade groove is hollowed out on the peripheral edge of the rotor disk by wire-cut electric discharge machining, and the hollow piece obtained by hollowing out the blade groove is used as a blade root, and the blade part separately formed on this blade root is heated with an electron beam. A method for manufacturing a blade wheel, characterized in that the blade roots of the integrally formed blade are fitted into the blade planting groove of the rotor disk by welding.