JPS61125702A - Method for machining steam turbine diaphgram - Google Patents

Abstract

PURPOSE:To connect a nozzle welding portion smoothly by storing strain amount corresponded to a rotating angle in a memory and reading previously to correct a phase shift amount with a data in the memory as a temporary delay system according to a detected value at the time of turning. CONSTITUTION:Diaphgram deformation amount is measured previously by a measuring unit 110 and taken in a correction data memory 116 by a value of an angle detector 108 mounted to a table. In non-circle machining, the value of the detector 108 and a value of a rotating speed detector 109 are taken by table rotating number, and phase delay corresponding to rotating speed is computed by deformation frequency by the rotating number and measurement data in a correction data memory address arithmetic circuit 112 successively to perform previous reading. Attaining ratio correction is made by the taking-in data in a correction data arithmetic editing circuit 114, and non-circle machining is made by pulse output by multiplying the data of previous reading of the phase delay of the memory 116 by the reciprocal of the attaining ratio.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a processing method in which a steam turbine nozzle and a partition plate are welded together and then subjected to cutting processing t2+dx to produce a diaphragm. be.

[Background of the invention]

First, the general procedure for manufacturing the ear 7 ram mentioned above will be explained.

FIG. 2 shows a cross-sectional view of the vicinity of the diaphragm of the steam turbine. A steam turbine is a machine that converts thermal energy of steam into rotational energy of a turbine rotor 4.

Steam is blown onto the rotor blades 5 of the turbine rotor 4 through a 7-diameter nozzle 2't-. The nozzle is outer ring 1,
The rotor blades attached to the inner ring 3 are separated from other stages by a seal packing 6, and the structure is such that steam passes between the rotor blades. The diaphragm 1, which has seven diamonds as a bird symbol and the following colors are shown in FIG. 3, is divided into upper and lower halves and installed between the stages of the rotor. Here, Fig. 4 shows the steam turbine diagram 2.
This section shows the steps for making a simulator. The steering ring 7 is provided with a hole 7a having the cross-sectional shape of the nozzle 3, and the nozzle 3 is assembled so that the cross-section of the passage of the nozzle is uniform and maximum efficiency is maintained according to the design value. As shown in the figure, the nozzle 3 installed in the hole 7a of the base ring is attached to the outer ring 1 with a welding groove. It is set between the inner rings 2, and as shown in FIG. At this time, welding distortion occurs in both the inner and outer rings due to thermal effects during bath welding. Figure 6 is A of Figure 5.
The arrow 9 shows a diagram, and numeral 9 indicated with parallel diagonal lines represents the strain caused by the condensation.

In the prior art, the diagram semi-finished product lO, which has been distorted as described above, is set up and rotated on a turning table 11 as shown in FIG.
A cutting tool attached to the tip of the machine was moved in the X-axis and Z-axis directions to cut out a perfect circle.

In the process described above, the cross-sectional area of the steam passing between the nozzles is not uniform, so the area near the base of the outer ring 1 and the nozzle 2 is shown with parallel diagonal lines as shown in Figure 8. Part 13 was removed by manual glider machining #)l! 7
34449, which was finished so that the outlet of the nozzle 2 and the side surface of the outer ring 1 were smoothly continuous to prevent steam vortex loss.
The figures are partially exploded views drawn to show the shape of the grinder-processed portion 13 described above.

Conventional processing methods in which finishing was done by hand required a high degree of skill and a great deal of labor, leading to an increase in manufacturing costs.

[Purpose of the invention]

The present invention was developed in consideration of the above-mentioned 4 km, and allows the nozzle welding part of the diaphragm to be smoothly connected to the inner and inner parts of the inner and outer rings without any manual work. The purpose of this invention is to provide an automatic machining method that can maintain the

There is no prior known technology for cutting the diagram of a steam turbine using an automatic machine as described above, and conventionally all cutting has been done by hand.

[Low position of invention]

First, the basic principle of the processing method of the present invention created to achieve the above object will be briefly described.

While rotating the diaphragm semi-finished product, which is the workpiece, which has undergone welding distortion, on a turning table, the amount of distortion is measured in advance before cutting, and the amount of distortion is stored in correspondence with the rotation angle. During cutting, based on the above stored data, the amount of movement of the cutting edge is sent as a pulse signal to the pulse acquisition section of the NC cutter in response to changes in the rotation angle of the workpiece.
Machining non-circular deformed parts. At this time, the NC controller can be thought of as a first-order delay system, and the output value has a phase difference with respect to the input pulse, and the command arrival rate may not be 100% due to the position gain of the system and the angular velocity of the movement amount. First, automatic correction processing is required, but the processing method of the present invention makes this possible as will be described later.

In order to achieve the above purpose (to automatically cut into a proper and smooth shape) based on the above-mentioned principle, the turbine diamond 72mm processing method of the present invention has a bath welding configuration to avoid distortion. Turning means (
Therefore, the amount of strain is measured while being supported and rotated, and the amount of strain is detected in advance in correspondence with the rotation angle, and stored in a memory device.
Ku.

Then, the pupil of the machining process, its rotation angle, and rotation speed are detected, and according to the detected values, the data in the memory device is read in advance by the amount of phase shift, taking into consideration the specific number of NC controllers as a temporary delay system. The present invention is characterized in that the command arrival rate is corrected and then input to the NC controller as an addition/subtraction pulse, and this value is superimposed on the NO command value for basic shape machining. 1st
FIG. 0 is a perspective view of the machining state shown for explaining the state of cutting by the method of the present invention, and corresponds to FIG. 8 in the prior art. 1 is an outer ring, 2 is a nozzle, and 6 is a seal packing.The two-dot chain line is a perfect circle shown for reference, and the solid line Cut is a cutting surface. According to the present invention, as described below, it is possible to smoothly connect the mounting portion of the nozzle 2 and the side surface of the outer ring 1, and to make the passage area of the nozzle outlet match the design value.

FIG. 11 is a developed view of the portion shown in FIG. 1O, and corresponds to FIG. 9 in the prior art. However, in Fig. 11, the parts shown with parallel hatching represent the steam passage (cross section of the space between the nozzles) after being mechanically cut by automatic control. .

[Embodiments of the invention]

K, which automatically processes the diaphragm, uses NC turning, but the NC control system can be approximated by a first-order lag system. If the input command value is Aa, the output value is Ac, and the yarn position gain is 1/T1, and the command angular velocity of the moving axis is ω (rud/5ec), the arrival rate of the command value (crossing -1 is Ac/A, = 1/1+(alT)'' phase delay is expressed as p = tan -'(J)'I' (deg). Here, ω is a function of the period of deformation of the workpiece and the rotational speed of the table.

A graph of these relationships is shown in Figure 12. It can be seen that the larger the positive gain, the better the machining can be done, but with the current turning control, the limit is around 6QSeO-'. In the method of the present invention, K
This technique solves this technical problem, eliminates the effects of the above-mentioned arrival rate and phase delay, and maintains manufacturing tolerances.

FIG. 1 is a block diagram of the steam terpino diaphragm in this embodiment.

Prior to machining, the amount of diaphragm deformation is measured with a measuring device 110, and the value of the angle detector 108 attached to the table is taken into the correction data memory 116. When performing non-circular blade loe, the value of the angle detector 108 and the value of the rotational speed detector 109 are taken in by rotating the turntable, and the rotational speed is matched by the deformation frequency of the workpiece based on the rotational speed and measurement data. The phase delay is calculated one by one by the correction data memory address arithmetic circuit 112, and data is read in advance. Further, the arrival rate correction is also performed by the correction data arithmetic and editing circuit 114 using the same captured data, and the data pre-read by the phase delay in the memory 116 is multiplied by the reciprocal of the arrival rate, and the pulse circuit 115 adds and subtracts a pulse that allows regular non-circular machining to be performed at all times. Create with.

This pulse is sent to the Xflll correction/curse capture circuit of the IqC control device, and the NC control device superimposes addition/subtraction pulses on the perfect circular machining data based on the NC tape command to perform non-circular machining with no phase delay and an arrival rate of too. be able to. 101 is a Z-axis servo motor, 102 is a FiX-axis servo motor, 103 is a tool bar, 104 is a tool, 107
is an NC control device, and 3111 is a non-circular machining control device.

〔Effect of the invention〕

As described in detail above, according to the processing method of the present invention, it is possible to smoothly connect the Guyafram nozzle welding part and the true interior of the inner and outer rings without using manual labor, and to disconnect each steam flow path. It has an excellent practical effect in that cutting can be performed under automatic control so that the area is equal to the design value, and it greatly contributes to improving the performance of steam turbines and reducing costs.

[Brief explanation of the drawing]

Fig. 1 is a processing control block diagram of an embodiment of the present invention, Fig. 2 is a cross-sectional view of the steam turbine, Fig. 3 is a cross-section diagram of the diaphragm, and Fig. 4 is an explanation of the diaphragm bowing process. 5 is a perspective view showing the diaphragm welding situation, FIG. 6 is an explanatory view showing the welding deformation of the inner and outer rings, and FIG. 7 is a perspective view showing the turning process. FIG. 8 is a partial perspective view for explaining cutting in the prior art, and FIG. 9 is a partial exploded view. FIG. 10 is an example of a partial perspective view for explaining the cutting situation when the present F3A is applied, and FIG. 11 is an example of a partial exploded view. FIG. 12 is a chart showing the relationship between the movement of the tool post and the machining shape. 1...Diaphragm outer ring, 2...Nozzle, 3...
Diaphragm inner ring, 4...Turbine rotor, 5...
Dynamic JK, 6... Seal packing, 7... Spacer ring, 8... Welded part, 9... Welded deformed part, 10...
・Diaphragm, 11... Turntable, 12...
・Tool bar, 13...Glider processing section, 101...
・Z-axis servo motor, 102...X-axis servo motor,
103... Toolbar, 104... Tool, 107
... NC control device, 108 ... Turntable rotation angle detector, 109 ... Turntable rotation speed detector, 110 ... Workpiece deformation measuring device, 111 ... Non-circular processing control device.

Claims (1)

[Claims] 1. Support the semi-finished product of the welded diaphragm by a turning means, measure it while rotating, detect the amount of distortion in advance in correspondence with the rotation angle, and store it in a memory device. When turning, the rotation angle and rotation speed are detected, and the data in the memory device is transferred to the NC as a temporary delay system according to the detected values.
Taking into consideration the specific number of controllers, the phase shift can be read in advance, the command arrival rate can be corrected, and then input to the NC controller as addition/subtraction pulses, and this value can be superimposed on the NC command value for basic shape machining. Characteristic steam turbine diaphragm processing method.