BLISK MACHINING CENTER

The present invention provides a blisk machining center, including: A-axis rotary assembly, B-axis rotary assembly and C-axis rotary assembly, wherein the A-axis rotary assembly drives the blisk to rotate, the B-axis rotary assembly drives an attachment head to rotate, and the attachment head drives a tool to machine the blisk, and the C-axis rotary assembly drives the A-axis rotary assembly to rotate, wherein the intersection of the rotation axis of the B-axis rotary assembly and the rotation axis of the C-axis rotary assembly is the center of the machining area of the blisk, and the tip point of the tool is on the rotation axis of the B-axis rotary assembly. In the present invention, the machining area is near the rotation center of the C-axis turntable, which ensures that the speed and acceleration of the movement of each physical axis are kept within a lower range than those of general machine tools when the machine tool is performing the machining of the 5-axis rotary tool center point.

TECHNICAL FIELD

The present invention relates to the field of machine tool machining, in particular to a blisk machining center.

BACKGROUND ART

The use of blisks in aero-engines is a development trend of aero-engine technology in the world. In order to expand the application of blisks in aero-engines, difficulties in manufacturing the blisks must first be solved. At present, our aero engines are less likely to use blisks, and the main reason why they are not widely available is that the technical difficulties of manufacturing the blisks are still not solved. The difficulties in manufacturing aero-engine blisks lie in the complex profile of the blade, high machining accuracy and surface quality requirements, extremely high blade machining consistency, blade machining deformation and the materials used. The surface of the blisk blade is mostly free-form, which puts additional extremely high requirements on the machining accuracy and surface roughness of the blade. It is easier to achieve such machining accuracy when the surface to be machined is plane or cylindrical, but it is more difficult to achieve such machining requirements on a free-form surface. The tool movement space is limited during machining, which makes it more difficult to achieve high machining accuracy for the blade. Therefore, the machining of aero-engine blisks is a problem all over the world. Existing machine tools have extremely high requirements on the motion speed and acceleration range of each physical axis when performing the machining with the 5-axis rotary tool.

SUMMARY OF INVENTION

The present invention provides a blisk machining center to overcome the above technical difficulties.

The present invention provides a blisk machining center, including: A-axis rotary assembly, B-axis rotary assembly and C-axis rotary assembly, whereinthe A-axis rotary assembly drives a blisk to rotate,the B-axis rotary assembly drives an attachment head to rotate, and the attachment head drives a tool to machine the blisk,the C-axis rotary assembly drives the A-axis rotary assembly to rotate,the intersection of a rotation axis of the B-axis rotary assembly and a rotation axis of the C-axis rotary assembly is the center of the machining area of the blisk, and a tip point of the tool is on the rotation axis of the B-axis rotary assembly.

Further, the A-axis rotary assembly is an A-axis turntable driving the blisk to rotate,the B-axis rotary assembly includes an attachment head on which the tool is fixed and a B-axis turntable (5), and the B-axis turntable (5) drives the attachment head (6) to rotate,the C-axis rotary assembly is a C-axis turntable,the A-axis turntable and the C-axis turntable are is detachably connected,the rotation axis of the C-axis turntable is perpendicular to the horizontal plane, and is perpendicular to the rotation axis of the blisk.

Further, the A-axis turntable is fixed to the top surface of the C-axis turntable, and a central axis of the A-axis turntable is the rotation axis of the blisk.

Further, a tool magazine is included for replacing the tool, and the tool magazine is on the same side as the attachment head.

In the present invention, the machining area is near the rotation center of the C-axis turntable, which ensures that the speed and acceleration of the movement of each physical axis are kept within a lower range than those of general machine tools when the machine tool is performing the machining of the 5-axis rotary tool center point (hereinafter referred to as RTCP), and the central axis of the attachment head and the central axis of a ram form an included angle of 45° to ensure that the large speed and acceleration of the linear axis are avoided when the attachment head rotates the RTCP action.

DESCRIPTION OF EMBODIMENTS

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the embodiments to be described are some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by a person skilled in the art without creative efforts are within the protection scope of the present invention.

The present invention provides a blisk machining center, as shown inFIG.1, which is a schematic diagram of the overall structure of the blisk machining center according to the present invention, including: a bed1, a sliding table3, column4and a ram, wherein the sliding table3and the bed1are slidably connected through guide rails, the column4and the sliding table3are slidably connected through guide rails, and one end of the ram and the column4are slidably connected through the guide rails, and further including: an A-axis rotary assembly, a B-axis rotary assembly and a C-axis rotary assembly, whereinthe A-axis rotary assembly drives blisk8to rotate,the B-axis rotary assembly drives an attachment head6to rotate, and the attachment head6drives a tool7to machine the blisk8,the C-axis rotary assembly drives the A-axis rotary assembly to rotate, whereinthe intersection of a rotation axis of the B-axis rotary assembly and a rotation axis of the C-axis rotary assembly is the center of the machining area of the blisk8, and a tip point of the tool7is on the rotation axis of the B-axis rotary assembly.

Further, the A-axis rotary assembly is an A-axis turntable10driving the blisk8, and the B-axis rotary assembly includes an attachment head6on which the tool7is fixed and a B-axis turntable5, the attachment head6being a 45° attachment head; one end of the 45° attachment head6and one end of the B-axis turntable5are rotatably connected, the tool7and the other end of the 45° attachment head6are fixedly connected, and the tool7is coaxial with the 45° attachment head6; the included angle between the central axis of the tool7and the axis of the B-axis turntable5is 45°; the C-axis rotary assembly is a C-axis turntable9driving the A-axis turntable10to rotate; the A-axis turntable10and the C-axis turntable9are detachably connected, thus allowing to adjust the position of the A-axis turntable10before operation, and the drive output end of the A-axis turntable10and the blisk8are connected; the rotation axis of the C-axis turntable9is perpendicular to the horizontal plane, and is perpendicular to the rotation axis of the blisk8, and the tool7machines the blisk8; and the A-axis rotary assembly and the C-axis rotary assembly are located in front of the 45° attachment head6.

FIG.2is another perspective view of the overall structure of the blisk machining center according to the present invention, the blisk machining mechanism including: a B-axis turntable5driving the 45° attachment head6to rotate, an A-axis turntable10driving the blisk8to rotate, a C-axis turntable9driving the A-axis turntable10to rotate and a driving mechanism11driving the C-axis turntable9to rotate. The C-axis turntable9is circular, and the C-axis turntable9is parallel to the horizontal plane; the C-axis turntable9is fixed on the top surface of the A-axis turntable10; the driving output end of the driving mechanism11and the C-axis turntable9are connected; the A-axis turntable10and the C-axis turntable9are detachably connected, the A-axis turntable10has a built-in driving motor, and the output end of the driving motor and the blisk8are rotatably connected; the driving mechanism11has a built-in driving motor, which drives the C-axis turntable9to rotate about C-axis, the C-axis turntable9drives the A-axis turntable10to rotate synchronously, and the A-axis turntable10drives the blisk8to rotate about the A-axis; the rotation axis of the C-axis turntable9is perpendicular to the horizontal plane and is perpendicular to the rotation axis of the blisk8, and the tool7machines the side edge of the blisk8.

As shown inFIG.3, the 45° attachment head6rotates about the B-axis; the intersection of a rotation axis of the B-axis rotary assembly and a rotation axis of the C-axis rotary assembly is the center of the machining area of the blisk8, and a tip point of the tool7is on the rotation axis of the B-axis rotary assembly.

In the present invention, the machining area is near the rotation center of the C-axis turntable, which ensures that the speed and acceleration of the movement of each physical axis are kept within a lower range than those of general machine tools when the machine tool is performing an RTCP machining, and the included angle a between the central axis of the 45° attachment head6and the central axis of the B-axis turntable5is 45°, to ensure that the large speed and acceleration of the linear axis are avoided when the 45° attachment head rotates the RTCP action.

Further, in order to facilitate the replacement of the tool7that is worn out during long-term machining, a tool magazine2is further included for replacing the tool7, and the tool magazine2is on the same side as the 45° attachment head6, the tool magazine2including: a cutter head2-1and a tool holder2-2, the cutter head2-1being rotatably connected to the tool holder2-2, the rotation axis of the cutter head2-1being parallel to the horizontal plane; the tool7is snap connected to the side edge of the cutter head2-1. The blisk8can be machined one by one, and the blades of the blisk8can be machined through replacing the tool in the tool magazine2; the 45° attachment head6moves alternately along the Z axis, the Y axis and the X axis to the cutter head2-1, and the cutter head2-1is driven by the motor to rotate (the drive motor of cutter head2-1is not illustrated) to make the hole position where the tool7is fixed to return to the initial position and the 45° attachment head6snaps the used tool into the hole position, and then the cutter head2-1rotates the tool7fixed thereon to the initial position, and the 45° attachment head6grabs the tool and starts to machine the next blisk.

Further,FIG.4shows a machining method based on the above-mentioned machining center, including the following steps:

S1: the 45° attachment head rotates about the B-axis, the 45° attachment head drives the tool to rotate synchronously, and machines the blisk side edge;

S2: the C-axis turntable9drives the A-axis turntable10and the blisk8to rotate about the C-axis, and the tool7machines the blisk8from another angle until the machining of one blade8-1is completed;

S3: the A-axis turntable10drives the blisk8to rotate about the A-axis, and the tool7machines the blade at another point on the side edge of the blisk8until the machining of the plurality of blades on the side edge of the blisk is completed.

S4: After the blade machining is completed, the 45° attachment head6drives the tool7to move to the tool magazine2along the Z axis to replace the tool7.

The diameter of the blisk to be machined by the present invention is about 1 m, and the length of the blade is about 200 mm. The present invention uses the C-axis of the C-axis turntable9and the B-axis of the 45° attachment head6to perform 5-axis RTCP machining. The C-axis of the C-axis turntable9is a transfer axis and does not participate in the linked machining.

The present invention has the following advantages:

1. The relative position of the blisk8and the C-axis turntable9is set to ensure that the machining area is near the rotation center of the C-axis turntable9, thus ensuring that the speed and acceleration of the movement of each physical shaft can be kept within a lower range than those of general machine tools when the machine tool is performing the machining of the 5-axis rotary tool center point.

2. The central axis of the 45° attachment head6and the central axis of the B-axis turntable5form an included angle of 45°, and the tip point of the tool7is on the central axis of the B-axis turntable5, to ensure that the large speed and acceleration of the linear axis are avoided when the 45° attachment head performs the RTCP rotation.

3. The bulky spindle is prevented from moving along the X, Y and Z axes during machining.

Therefore, compared with the existing machine tool, the present invention can make the distance between the tool and the rotation center of the 45° attachment head as close as possible when using a longer tool, thereby reducing the speed and acceleration requirements of the RTCP action on the linear axis.

In summary, the present invention has obvious advantages in the blisk machining, especially in the machining of the leading edge and the trailing edge of the blade where the rotary axis movement is large. As a result of the simulation test,FIG.5shows the velocity profiles of the X-axis, Y-axis and Z-axis during the machining of the blade according to the present invention, andFIG.6shows the velocity profiles of the X-axis, Y-axis and Z-axis during the machining of the blade according to the prior art. After running the same machining program on the present invention and the existing machine tool, and then comparing the velocity profiles of X-axis, Y-axis and Z-axis inFIG.5andFIG.6, it can be seen that the speed and acceleration of each physical shaft when machining the blade according to the present invention can be kept in a lower range than those of the existing machine tool.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, a person skilled in the art should understand that: the technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features thereof can be equivalently substituted. However, these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.