A method for aligning milling of a nozzle ring blade

Abstract

The application discloses a kind of milling processing alignment method of nozzle ring blade, improve the efficiency of alignment and the qualified rate of processing.Nozzle ring blade is fixed in milling tooling along vertical direction on the worktable of machining center, milling tooling is equipped with direction mark, the direction mark of milling tooling is clamped towards the negative direction of machining center Y axis under clamped state;End of nozzle ring blade is fixed in milling tooling along vertical direction;Tool setting block is installed to the shaft end surface groove of nozzle ring blade, and the alignment surface of tool setting block is aligned;Tool setting block is removed, auxiliary disc is placed on the shaft positioning stop of nozzle ring blade, the needle of dial gauge is pressed on the outer ring of auxiliary disc, the highest point and the lowest point of auxiliary disc are found out, and the highest point mark is made;The highest point mark is rotated and moved to the positive direction of machining center Y axis;Through drawing calculation, the inclination of plane is calculated, so that the machining center is rotated by corresponding inclination number;C value shown by machining center is directly input into numerical control program for angle compensation.

Description

Technical Field

[0001] This invention relates to the field of machining technology, and in particular to a method for milling and aligning nozzle ring blades. Background Technology

[0002] The nozzle ring is a key component of the turbocharger. Inside the turbocharger, gas is accelerated and pressurized as it passes through the nozzle ring due to its unique internal geometry. Adjustable-blade nozzle rings allow for adjustment of the blade angle to alter the internal structure, thereby regulating the airflow velocity to meet different pressurization requirements.

[0003] like Figure 1 The image shown is a schematic diagram of a three-dimensional model of the nozzle ring blade casting. Figure 2 This is a three-dimensional schematic diagram of the nozzle ring blades. The content described in this patent is as follows: Figure 2 Clamping and alignment method for milling the blade root surface in a 3D schematic diagram of a nozzle ring blade.

[0004] The process route is as follows:

[0005] 1. On a milling and turning machining center, finish turn the shaft to the dimensions shown in the drawing, mill the flat side of the shaft to the dimensions shown in the drawing, and mill the keyway at the end of the shaft to the dimensions shown in the drawing. These dimensions are used for alignment of the milling surfaces in subsequent machining.

[0006] 2. Rough and finish mill the blade root surface on a milling machine;

[0007] 3. Position and clamp the blades by the shaft, and mill out the blade tip profile.

[0008] From the perspective of processing content, alignment is quite difficult in actual processing. Firstly, machine operators use milling fixtures, positioning the blade casting profile for clamping, with the machined shaft facing upwards, and establishing a machining coordinate system along the straight line of the keyway. Because the blades are cast, the error is relatively large. After clamping with the blade profile for positioning, the axis of the machined shaft is not perpendicular to the worktable. The worker must rely on feeler gauges placed under the fixture to correct the machining plane. This method requires the worker to continuously adjust with a dial indicator. Furthermore, because the feeler gauge width is fixed and the minimum thickness is 0.02mm, inserting the feeler gauge significantly affects the fixture area. Therefore, correcting the machining plane to within 0.015mm during alignment is extremely difficult. In actual operation, the alignment process takes an average of 2.5 hours, while the entire product processing time is less than 2 hours, greatly reducing the product's processing efficiency. After milling on a three-axis machining center, the average profile accuracy is within the range of 0.25-0.5, resulting in a low pass rate. Figure 3 As shown, the profile tolerance of this surface is required to be 0.3. Summary of the Invention

[0009] The purpose of this invention is to overcome the shortcomings of the prior art and provide a milling alignment method for nozzle ring blades, thereby improving alignment efficiency and increasing the product qualification rate.

[0010] The objective of this invention is achieved as follows:

[0011] A method for milling and aligning nozzle ring blades.

[0012] Step 1: On the cradle-type five-axis machining center, clamp the milling fixture onto the worktable. The A-axis and C-axis of the machining center can rotate. The milling fixture is equipped with a direction mark indicating the clamping direction of the nozzle ring blade. In the clamping state, the direction mark of the milling fixture is clamped towards the negative Y-axis direction of the machining center.

[0013] Step 2: Vertically clamp and fix the end of the nozzle ring blade onto the milling fixture;

[0014] Step 3: Install the tool setting block onto the end face groove of the nozzle ring blade, align the tool setting block with the facing face, and set the nozzle ring blade state to C0. At this time, the placement direction of the nozzle ring blade is consistent with the machining direction required by the CNC program, but the clamping accuracy of the nozzle ring blade is not yet up to standard.

[0015] Step 4: Remove the tool setting block, place the auxiliary disk on the shaft positioning stop of the nozzle ring blade, press the dial indicator needle on the outer ring of the auxiliary disk, and use the auxiliary handwheel of the machining center to rotate the C-axis. After rotating the C-axis multiple times, find the highest and lowest points of the auxiliary disk and mark the highest point.

[0016] Step 5: Use the auxiliary handwheel of the machining center to rotate the C-axis and move the highest point mark to the positive direction of the Y-axis of the machining center;

[0017] Step 6: Obtain the height difference by using the highest and lowest points of the auxiliary disk, calculate the plane inclination by drawing, input the calculated inclination into the A-axis parameters of the machining center and execute it to make the machining center rotate by the corresponding inclination degree;

[0018] Step 7: Input the C value displayed on the machining center directly into the CNC program for angle compensation. After compensation, collect the nozzle ring blade status as A0 and C0, collect the new coordinate origin, and run the CNC program to process the nozzle ring blade.

[0019] Preferably, the milling fixture is located at the center of the worktable of the machining center.

[0020] Preferably, the milling fixture has a toothed block inside. The mating surface of the upper end of the toothed block is made according to the theoretical curved surface size of the end profile of the nozzle ring blade. When clamping, the end profile of the nozzle ring blade is close to the mating surface of the toothed block for positioning, and then the fixing screw is tightened for fixation.

[0021] Preferably, the cutting block has a rectangular plate structure, the side of the cutting block is the facing side, and the bottom of the cutting block is provided with a locking block, which is used to be positioned by being embedded in the groove of the shaft end face of the nozzle ring blade.

[0022] Preferably, the auxiliary disk has a cylindrical section, which is fitted onto the shaft of the nozzle ring blade, and the end face of the cylindrical section contacts the shaft positioning stop of the nozzle ring blade for positioning.

[0023] Preferably, after step six, the flatness of the auxiliary disk plane is checked using a cross dial indicator, and the A and C axes are fine-tuned to bring the flatness within 0.015.

[0024] Preferably, if the flatness is not calibrated to within 0.015 in one go, it can be adjusted by fine-tuning the A-axis and C-axis of the machining center.

[0025] Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0026] This method can reduce the alignment and clamping time on a three-axis machining center from 2.5 hours to 20-30 minutes, improve alignment efficiency, increase the alignment flatness from 0.02-0.03 to 0.01-0.015, and increase the product processing qualification rate from 60% to over 95%. Attached Figure Description

[0027] Figure 1 A 3D drawing of the nozzle ring blade casting blank;

[0028] Figure 2 This is a three-dimensional schematic diagram of the nozzle ring blades;

[0029] Figure 3 This is a front view of the nozzle ring blades;

[0030] Figure 4 Top view of the nozzle ring blades;

[0031] Figure 5 This is a clamping diagram of the milling fixture for the nozzle ring blades;

[0032] Figure 6 A schematic diagram showing the position and orientation of the spindle and rotary axes of a cradle-type five-axis machining center;

[0033] Figure 7 Tool setting block to assist in rough C-axis alignment;

[0034] Figure 8 An auxiliary disk for assisting in A-axis alignment and fine-tuning;

[0035] Figure 9 This is a schematic diagram for fine-tuning and calibration;

[0036] Figure 10This is a schematic diagram of the milling fixture for the nozzle ring blade.

[0037] Figure Labels

[0038] In the attached diagram, 1 is a connecting bolt, 2 is a tooling clamping bolt, 3 is a tooling clamping block, 4 is a cylindrical clamping screw (fitted on the cylindrical section of the radial clamping and fixing auxiliary disc, with a corresponding limiting step on the shaft of the nozzle ring blade), 5 is an auxiliary disc, 6 is a tool setting block, 7 is a milling tool body, and 8 is a fastening screw (used for blade clamping). Detailed Implementation

[0039] This patent describes a clamping and alignment method for milling the root curved surface of a nozzle ring blade on a cradle-type five-axis machining center. The spindle and rotary axis of the cradle-type five-axis machining center are as follows: Figure 6 As shown, this type of machining center has rotatable A and C axes. The alignment method described in this patent utilizes the rotatable A and C axes of this type of equipment for product alignment. The main contents of this patent are:

[0040] 1. There is a toothed block inside the milling fixture. The surface of the toothed block is made according to the theoretical curved surface size of one side of the blade surface. When clamping, tighten the fixing screw after the nozzle ring blade and the toothed block mating surface are close together.

[0041] 2. The tooling has a face-finding feature. After the face-finding feature is aligned, the current state is collected as C0. At this time, the part placement is consistent with the part machining direction required by the programming, but the clamping accuracy of the part does not meet the requirements.

[0042] 3. The shaft and end face of the nozzle ring blade are small, so the flatness of its shaft positioning plate cannot be directly tested. An auxiliary disc is needed. Place the auxiliary disc naturally on the shaft positioning plate, as shown in the figure.

[0043] 4. Press the dial indicator needle against the outer ring of the auxiliary disk and use the machine tool auxiliary handwheel to rotate the C-axis. After rotating the C-axis multiple times, find the highest point of the auxiliary disk and mark it. Rotate and move the mark to the positive direction of the Y-axis.

[0044] 5. When rotating the C-axis to find the height difference of the auxiliary disk, record the height difference and calculate the plane inclination by drawing. Input the calculated inclination into the machine tool A-axis parameters and execute the operation to make the machine tool rotate the corresponding inclination degree.

[0045] 6. After performing the above operations, use the cross dial indicator method to check the flatness of the auxiliary disk plane. After coarse adjustment, the flatness is greatly improved. Only fine adjustment of the A and C axes is needed to easily correct the flatness to within 0.02.

[0046] 7. Record the machine tool's C value under the above conditions, and re-acquire the machine tool's current state as A0 and C0. Input the recorded C value directly into the CNC program's coordinate rotation command;

[0047] 8. Execute CNC programs to process parts.

[0048] The specific steps are as follows:

[0049] Step 1: Clamp the tooling onto the worktable, with the tooling direction mark facing the Y-direction of the machine tool spindle, and clamp it roughly at the center of the worktable to facilitate subsequent alignment;

[0050] Step 2: Insert the nozzle ring blade with the inner arc facing the tooth block, tighten the screw on the other side, and press the blade against the tooth block to complete the initial clamping.

[0051] Step 3: Install the tool setting block onto the spindle end face groove and set the long side of the tool setting block to C0;

[0052] Step 4: Remove the tool setting block, install the auxiliary disc onto the shaft, use a dial indicator to rotate and roughly mark the highest point of the outer circular plane on the tool setting disc;

[0053] Step 5: Use the handwheel to move the marked highest point to the Y+ direction of the machine tool spindle, and use a dial indicator to mark the height difference between Y+ and Y-, which is the difference between the high and low points of the surface;

[0054] Step 6: The angle value of the height difference can be obtained by drawing, and the obtained angle value is input into the A axis of the machine tool. At this time, the flatness of the dial indicator base can be adjusted by the cross adjustment method to obtain a roughly horizontal plane.

[0055] Step 7: If the plane is not aligned to 0.015 in one go, it can be adjusted by fine-tuning the A / C axis. After coarse adjustment, fine adjustment can quickly correct the problem.

[0056] Step 8: After setting C0 in the early stage and adjusting it, the C value displayed on the machine tool is directly input into the CNC program for angle compensation. After compensation, the current part status is collected as A0\C0, and the new coordinate origin is collected. Then, the CNC program is run.

[0057] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. A method for milling and aligning nozzle ring blades, characterized in that: Step 1: On the cradle-type five-axis machining center, clamp the milling fixture onto the worktable. The A-axis and C-axis of the machining center can rotate. The milling fixture is equipped with a direction mark indicating the clamping direction of the nozzle ring blade. In the clamping state, the direction mark of the milling fixture is clamped towards the negative Y-axis direction of the machining center. Step 2: Vertically clamp and fix the end of the nozzle ring blade onto the milling fixture; Step 3: Install the tool setting block onto the end face groove of the nozzle ring blade, align the tool setting block with the facing face, and set the nozzle ring blade state to C0. At this time, the placement direction of the nozzle ring blade is consistent with the machining direction required by the CNC program, but the clamping accuracy of the nozzle ring blade is not yet up to standard. Step 4: Remove the tool setting block, place the auxiliary disk on the shaft positioning stop of the nozzle ring blade, press the dial indicator needle on the outer ring of the auxiliary disk, and use the auxiliary handwheel of the machining center to rotate the C-axis. After rotating the C-axis multiple times, find the highest and lowest points of the auxiliary disk and mark the highest point. Step 5: Use the auxiliary handwheel of the machining center to rotate the C-axis and move the highest point mark to the positive direction of the Y-axis of the machining center; Step 6: Obtain the height difference by using the highest and lowest points of the auxiliary disk, calculate the plane inclination by drawing, input the calculated inclination into the A-axis parameters of the machining center and execute it to make the machining center rotate by the corresponding inclination degree; Step 7: Input the C value displayed on the machining center directly into the CNC program for angle compensation. After compensation, collect the nozzle ring blade status as A0 and C0, collect the new coordinate origin, and run the CNC program to process the nozzle ring blade.

2. The milling and alignment method for nozzle ring blades according to claim 1, characterized in that: The milling fixture is located at the center of the worktable of the machining center.

3. The milling and alignment method for nozzle ring blades according to claim 1, characterized in that: The milling fixture has a toothed block inside. The mating surface of the upper end of the toothed block is made according to the theoretical curved surface size of the end profile of the nozzle ring blade. When clamping, the end profile of the nozzle ring blade is close to the mating surface of the toothed block for positioning, and then the fixing screws are tightened for fixation.

4. The milling and alignment method for nozzle ring blades according to claim 1, characterized in that: The tool setting block has a rectangular plate structure. The side of the tool setting block is the front facing, and the bottom of the tool setting block is equipped with a locking block, which is used to be positioned by embedding into the groove on the shaft end face of the nozzle ring blade.

5. The milling and alignment method for nozzle ring blades according to claim 1, characterized in that: The auxiliary disc has a cylindrical section that is fitted onto the shaft of the nozzle ring blade, and the end face of the cylindrical section contacts the shaft positioning stop of the nozzle ring blade for positioning.

6. The milling and alignment method for nozzle ring blades according to claim 1, characterized in that: After step six, use the cross dial indicator method to check the flatness of the auxiliary disk plane, and make fine adjustments to the A and C axes to calibrate the flatness to within 0.

015.

7. The milling and alignment method for nozzle ring blades according to claim 6, characterized in that: If the flatness is not calibrated to within 0.015 in one go, it can be adjusted by fine-tuning the A-axis and C-axis of the machining center.

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