A machining method for ensuring the coaxiality of multi-stage boring of a gearbox assembly

Abstract

The present invention relates to the technical field of machining, and particularly relates to a machining method for ensuring the coaxiality of multiple boring holes in a gearbox assembly. A first coordinate origin is set on the flange surface, the high-speed shaft hole, the second hole and the third hole are rough bored, and the facing plate is replaced; the high-speed shaft hole is calibrated to set a second coordinate origin, the outer circle of the flange end face is bored, and the facing plate is retracted; the high-speed shaft hole is calibrated on the reverse side, the high-speed shaft hole, the second hole, the third hole and the remaining holes are bored on the reverse side, the rear cover is removed to machine the internal counterbore and screw holes of the gearbox. This method first rough bores the main hole, and with the rough bored main hole as the reference, under the condition of calibrating the facing plate, the outer circle of the facing plate is bored. At this time, the coaxiality of the rough bored hole and the flange can be ensured. After rotating 180 degrees, the rough and finish boring of each hole at the rear cover end is carried out again with the rough bored coordinate system to ensure the unity of the base holes bored twice, improve the clearance accuracy of the gearbox, and thus improve the machining qualification rate of the gearbox.

Description

Technical Field

[0001] The present invention relates to the technical field of machining, and particularly relates to a machining method for ensuring the coaxiality of multi-stage boring holes of a gearbox assembly. Background Art

[0002] As a common speed-changing device, the gearbox is applied to a steam compressor and transmits speed through gears on the high-speed and low-speed shafts. High requirements are imposed on both the dimensional accuracy and the position accuracy of each hole system of the gearbox.

[0003] The gearbox is mainly machined on a boring and milling machining center. Taking a four-axis floor-type boring and milling machining center as an example for machining analysis, this type of machine tool belongs to a relatively large machine tool, and there are certain errors in the spindle conversion. Generally, the center error fluctuates within the range of 0.04 - 0.08. When the workbench rotates 180 degrees, since the gearbox is a non-rotary part, it is almost impossible to clamp the center of the part at the center of the workbench. Therefore, when rotating, there will also be errors due to clamping and part changes. When boring the reverse side and the flange, these two errors will greatly affect the coaxiality and position accuracy corresponding to the boring holes. When boring holes on this type of machine tool, it can be seen that there are three axes, namely V, W, and Z, moving in the boring direction, and the three axes can move independently. The accuracy requirements of the machine tool allow a certain angle between the axes within a certain range. The non-fixed-axis movement will also affect the coaxiality between the holes. Under the influence of various factors mentioned above, it is not easy to ensure the accuracy of the gearbox clearance, and the qualified rate of the gearbox is less than 50%, which is relatively low. Summary of the Invention

[0004] An object of the present invention is to provide a machining method for ensuring the coaxiality of multi-stage boring holes of a gearbox assembly, aiming to solve the problem of relatively low qualified rate in the existing machining of gearboxes.

[0005] To achieve the above object, the present invention provides a machining method for ensuring the coaxiality of multi-stage boring holes of a gearbox assembly, including the following steps:

[0006] Set the positive base hole on the flange as the first coordinate origin, rough-bore the high-speed shaft hole, the second hole, and the third hole, and replace the faceplate.

[0007] Align the high-speed shaft hole, and set the high-speed shaft hole as the second coordinate origin, bore the outer circle of the flange end face, and retract the faceplate.

[0008] Align the high-speed shaft hole on the reverse side, bore the high-speed shaft hole, the second hole, the third hole, and the remaining holes on the reverse side, and disassemble the rear cover to machine the internal counterbore and screw holes of the gearbox.

[0009] Among them, the specific method of setting the positive base hole on the flange as the first coordinate origin, rough-boring the high-speed shaft hole, the second hole, and the third hole, and replacing the faceplate is as follows:

[0010] Align the flange with the machine tool spindle to find the reference hole, and set the first coordinate origin at the reference hole;

[0011] Rough bore the high-speed shaft hole and the second hole on the flange surface;

[0012] Bore the third hole according to the tolerance dimension and replace the faceplate.

[0013] Among them, the specific method of aligning the high-speed shaft hole, setting the high-speed shaft hole as the second coordinate origin, boring the outer circle of the flange end face, and retracting the faceplate:

[0014] Use a dial indicator to align the high-speed shaft hole and set the high-speed shaft hole as the second coordinate point;

[0015] Bore the outer circle of the flange end face according to the tolerance dimension and replace the faceplate.

[0016] Among them, the specific method of aligning the high-speed shaft hole on the reverse side, boring the high-speed shaft hole, the second hole, the third hole and the remaining holes on the reverse side, and removing the rear cover to machine the internal counterbore and screw holes of the gearbox:

[0017] Use a dial indicator to align the high-speed shaft hole on the reverse side;

[0018] Bore the high-speed shaft hole and the second hole on the reverse side according to the tolerance dimension;

[0019] Bore the third hole and the remaining holes according to the tolerance dimension;

[0020] Remove the rear cover and machine the internal counterbore and screw holes of the gearbox.

[0021] Among them, the machine tool uses the V / Z / W three axes to perform corresponding length compensation for the tool.

[0022] A machining method for ensuring the coaxiality of multi-stage boring holes in a gearbox assembly. Set the first coordinate origin on the flange surface, rough bore the high-speed shaft hole, the second hole, and the third hole, and replace the facing head. Calibrate the high-speed shaft hole and set the second coordinate origin, bore the outer circle of the flange end face, and retract the facing head. Calibrate the high-speed shaft hole on the reverse side, bore the high-speed shaft hole, the second hole, the third hole, and the remaining holes on the reverse side, remove the rear cover and machine the internal counterbore and screw holes of the gearbox. This method achieves the coaxiality requirements of each level of holes and the flange by redefining the boring sequence, fixing the used axis of the machine tool, secondary calibration, etc., and reorganizes the machining steps. The holes and outer circles to be bored in the gearbox are located at both ends of the sub-assembly. Even when using an ultra-long boring tool, boring needs to be carried out separately from both ends. First, rough bore the main hole, and based on the rough-bored main hole, bore the outer circle of the facing head under the condition of calibrating the facing head. At this time, the coaxiality of the rough-bored hole and the flange can be ensured. After rotating 180 degrees, then rough and finish bore the holes at the rear cover end with the rough-bored coordinate system to ensure the unity of the basic holes bored twice. Fix the used axis of the machine tool. During the machining process, due to the different lengths of the tools, the machine tool spindle is often used for tool length compensation. This machine tool can use the V / Z / W three axes for corresponding length compensation. The boring and milling machining center used has the Z axis mounted on the machine tool ram. The machine tool ram is square. When the ram extends a certain length, it will sag to a certain extent in the Y direction due to the gravity of the ram, and this sag amount increases normally with the extension length of the ram. Therefore, the length of the Z axis should be kept unchanged during the boring process. When the tool performs length compensation, move the V axis of the workbench back and forth, and also use the V axis to move for boring during the boring process. The W axis has good rigidity when the spindle extends the shortest, and the W axis is not used for boring under non-essential circumstances. The benefits of fixing the Z axis and the W axis can also avoid the machining errors caused by the included angle between the V axis and the Z axis, and can circumvent factors such as machine tool accuracy and unstable environmental temperature, improve the consistency of product machining, and solve the problem of the low qualified rate of existing gearbox machining. Brief Description of the Drawings

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0024] Figure 1 Schematic diagram of the gearbox structure.

[0025] Figure 2 Front view structure diagram of the gearbox.

[0026] Figure 3 Structure diagram of the machine tool.

[0027] Figure 4 Structural diagram of faceplate

[0028] Figure 5 Schematic diagram of boring the high-speed shaft hole and the second hole

[0029] Figure 6 Schematic diagram of boring the third hole

[0030] Figure 7 Schematic diagram of boring the outer circle of the flange end face

[0031] Figure 8 Schematic diagram of boring a hole from the back cover surface

[0032] Figure 9 Schematic diagram of removing the back cover and drilling and milling the internal hole

[0033] Figure 10 It is a flowchart of a processing method for ensuring the coaxiality of multi-stage boring of a gearbox combination Specific implementation mode

[0034] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention

[0035] Please refer to Figures 1 to 10 , the present invention provides a processing method for ensuring the coaxiality of multi-stage boring of a gearbox combination, including the following steps:

[0036] S1 Set the positive base hole on the flange as the first coordinate origin, rough-bore the high-speed shaft hole, the second hole and the third hole, and replace the faceplate

[0037] Specific method:

[0038] S11 Align the flange towards the machine tool spindle to find the base hole, and set the positive base hole as the first coordinate origin

[0039] Specifically, the flange is aligned with the locating base hole B of the machine tool spindle and the first coordinate origin 1 is set. The machine tool can utilize the V / Z / W three axes to perform corresponding tool length compensation. The boring and milling machining center used has the Z axis mounted on the machine tool ram. The machine tool ram is square. When the ram extends a certain length, it will sag to a certain extent in the Y direction due to the gravity of the ram, and this sag amount increases normally with the extension length of the ram. Therefore, during the boring process, the length of the Z axis should be ensured to be constant. When the tool performs length compensation, the V axis of the worktable is moved back and forth. During the boring process, the V axis is also used to move for boring. The W axis has good rigidity when the spindle extends the shortest. Without necessity, the W axis is not used for boring. The advantage of fixing the Z axis and the W axis can also avoid the machining error caused by the angle between the V axis and the Z axis. The machine tool spindle can be directly installed with a boring tool for boring operations and can automatically call the faceplate for use. The faceplate is equipped with a movable U axis to control the boring surface and the size of the outer circle. The form of boring the outer circle and the end face is similar to the turning function. The machine tool worktable is equipped with a rotating B axis and can rotate 360°. When boring the gearbox, there is no need to re-clamp the gearbox for facing boring. When the gearbox is placed and clamped, in order to make the machine tool ram extend equal lengths at both ends to offset the gravity sag of the ram, the gearbox should be installed as close as possible to the middle position of the worktable. When aligning the zero point, the Z axis zero point is fixed first. After the tool is clamped on the spindle, the V axis is moved to the tool tip and V0 is set.

[0040] S12 Rough-bore the high-speed shaft hole and the second hole on the flange surface;

[0041] Specifically, starting from the flange surface, rough-bore the high-speed shaft hole B and the second hole 2, leaving a unilateral allowance of 0.5 mm for the hole.

[0042] S13 Bore the third hole according to the tolerance dimensions and replace the faceplate.

[0043] S2 Align the high-speed shaft hole and set the high-speed shaft hole as the second coordinate origin, bore the outer circle of the flange end face, and retract the faceplate;

[0044] Specific method:

[0045] S21 Use a dial indicator to align the high-speed shaft hole and set the high-speed shaft hole as the second coordinate point;

[0046] S22 Bore the outer circle of the flange end face according to the tolerance dimensions and replace and retract the faceplate.

[0047] Specifically, the tolerance dimensions: taking the high-speed shaft hole as the basic hole, the position tolerance of the remaining holes relative to the high-speed shaft hole is 0.02, and the coaxiality is 0.02.

[0048] S3 Align the high-speed shaft hole on the reverse side, bore the high-speed shaft hole, the second hole, the third hole and the remaining holes on the reverse side, and disassemble the rear cover to machine the internal counterbore and screw holes of the gearbox.

[0049] Specific method:

[0050] S31 Use the reverse side of the dial indicator to calibrate the high-speed shaft hole;

[0051] S32 Bore the high-speed shaft hole and the second hole on the reverse side according to the tolerance dimensions;

[0052] S33 Bore the third hole and the remaining holes according to the tolerance dimensions;

[0053] S34 Remove the rear cover and machine the internal counterbore and screw holes of the gearbox.

[0054] The above-disclosed is only a preferred embodiment of the present invention with a certain patent name. Of course, it cannot be used to limit the scope of the rights of the present invention. Those of ordinary skill in the art can understand all or part of the processes of implementing the above embodiments, and the equivalent changes made according to the claims of the present invention still fall within the scope covered by the invention.

Claims

1. A machining method for ensuring the coaxiality of multi-stage boring of a gearbox assembly, characterized in that, It includes the following steps: Set the positive base hole on the flange as the first coordinate origin, rough bore the high-speed shaft hole, the second hole and the third hole, and replace the faceplate; Align the high-speed shaft hole and set the high-speed shaft hole as the second coordinate origin, bore the outer circle of the flange end face, and retract the faceplate; Align the high-speed shaft hole on the reverse side, bore the high-speed shaft hole, the second hole, the third hole and the remaining holes on the reverse side, remove the rear cover and machine the internal counterbore and screw holes of the gearbox; The specific method of setting the positive base hole on the flange as the first coordinate origin, rough boring the high-speed shaft hole, the second hole and the third hole, and replacing the faceplate is as follows: Align the flange towards the machine tool spindle to find the base hole and set the positive base hole as the first coordinate origin; Start rough boring the high-speed shaft hole and the second hole from the flange surface; Bore the third hole according to the tolerance dimension and replace the faceplate; The specific method of aligning the high-speed shaft hole and setting the high-speed shaft hole as the second coordinate origin, boring the outer circle of the flange end face, and retracting the faceplate is as follows: Use a dial indicator to align the high-speed shaft hole and set the high-speed shaft hole as the second coordinate origin; Bore the outer circle of the flange end face according to the tolerance dimension and retract the faceplate; The specific method of aligning the high-speed shaft hole on the reverse side, boring the high-speed shaft hole, the second hole, the third hole and the remaining holes on the reverse side, removing the rear cover and machining the internal counterbore and screw holes of the gearbox is as follows: Use a dial indicator to align the high-speed shaft hole on the reverse side; Bore the high-speed shaft hole and the second hole on the reverse side according to the tolerance dimension; Bore the third hole and the remaining holes according to the tolerance dimension; Remove the rear cover and machine the internal counterbore and screw holes of the gearbox.

2. A machining method for ensuring the coaxiality of multi-stage boring holes of a gearbox assembly according to claim 1, wherein The machine tool utilizes the V / Z / W three axes to perform corresponding length compensation for the tool.

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