A multi-degree-of-freedom milling device for compressor blades

Abstract

A multi-degree-of-freedom milling device for compressor blades, comprising a blade positioning clamping device, an automatic tool changing device and a multi-axis robot arm; the blade positioning clamping device comprises a blade tenon processing clamping and positioning mechanism and a blade surface processing clamping and positioning mechanism, which are used to fix the engine blades; the automatic tool changing device comprises an automatic tool changing tool magazine mechanism and an automatic tool changing execution end mechanism; the multi-axis robot arm comprises a first axis structure of a base, a second axis structure, a third axis structure of a small arm, a fourth axis small arm structure, a fifth axis wrist structure and a processing spindle structure. The present invention provides a multi-degree-of-freedom milling device for compressor blades, which utilizes a robot arm to realize flexible milling and automatic tool changing, can make machine tool processing more flexible, fast and accurate, positioning more accurately and faster, blade processing efficiency is high, and blade surface milling quality is high.

Description

Technical Field

[0001] The invention relates to the field of milling devices, in particular to the field of multi-degree-of-freedom milling devices, and in particular to a multi-degree-of-freedom milling device for engine compressor blades. Background Art

[0002] At present, compressor blades are mostly manufactured using traditional CNC milling machines in combination with different templates, relying on the simultaneous movement of the machine tool and the template to achieve the processing of complex curved surfaces. This processing method has cumbersome and complicated steps, and the required template fixtures need to be specially made. The processing accuracy and efficiency are not ideal, and its development level is relatively limited. Most of them are still limited to semi-finishing of blades, and the final manufacturing quality of blades still depends on manual polishing process; it is completed by ordinary milling machine processing plus a large amount of manual grinding. This method is time-consuming, labor-intensive and has high labor costs; the processing results of such rough processing technology mainly have low processing efficiency, large part tolerance range, high equipment cost and labor cost, and low blade surface quality. These problems seriously restrict the development of engine blade manufacturing. Summary of the invention

[0003] In order to overcome the shortcomings of existing compressor blade processing methods such as low processing efficiency, large part tolerance range, high equipment cost and labor cost, and low blade surface quality, the present invention provides a multi-degree-of-freedom milling device for compressor blades, which uses a manipulator to achieve flexible milling and automatic tool changing, can make machine tool processing more flexible, fast and accurate, positioning more accurate and faster, blade processing efficiency high, and blade surface milling quality high.

[0004] The technical solution adopted by the present invention to solve its technical problem is:

[0005] A multi-degree-of-freedom milling device for compressor blades, comprising a blade positioning and clamping device, an automatic tool changing device and a multi-axis robotic arm; the blade positioning and clamping device comprises a blade tenon processing clamping and positioning mechanism and a blade surface processing clamping and positioning mechanism, which are used to fix the engine blades; the automatic tool changing device comprises an automatic tool changing tool magazine mechanism and an automatic tool changing execution end mechanism; the multi-axis robotic arm comprises a first axis structure of a base, a second axis structure, a third axis structure, a fourth axis structure, a fifth axis structure and a processing spindle structure.

[0006] The present invention utilizes the advantages of automation and research foundation of traditional precision CNC machine tools, combines the flexibility of multi-axis rotation of industrial robots, and the advantages of high positioning accuracy, and designs a multi-degree-of-freedom robotic arm milling device with finishing as the main function, which can realize the processing of complex spatial surfaces of engine blades.

[0007] Furthermore, the blade tenon processing clamping and positioning mechanism adopts a low-melting-point alloy wrapping method. The blank and the low-melting-point alloy are first melted and cast into a simple geometric shape. The blade cast and wrapped part is the positioning part, which is clamped up and down by the main clamp to limit the movement of the workpiece in the Z axis; secondly, there is a positioning baffle on the base of the main clamp to limit the movement of the workpiece in the X and Y axis directions. The upper and lower pressure blocks of the main clamp are pressed to provide clamping force, and the clamping force acts directly in the Z axis direction. The static friction force generated by the clamp pressing the workpiece surface coincides with the main axial milling force generated by the tool.

[0008] Furthermore, the blade surface is processed with a clamping and positioning mechanism, and a special clamp component is matched with the shape of the blade tenon, and the special clamp component is fixed on the threaded holes of the upper pressure block and the clamp base with screws. The shape of the special clamp component and the tenon directly limits the displacement of the workpiece in the Z and X axes; the extended baffles on both sides of the special component limit the displacement of the workpiece in the Y axis; the main clamp specifically provides the main clamping force, which coincides with the axial component of the milling force; the friction and extrusion force generated by the clamping force and the workpiece coincide with the main milling force; the auxiliary clamping mechanism is located at the other end of the workpiece to provide lateral clamping force.

[0009] Furthermore, the automatic tool changing tool magazine mechanism includes a tool magazine frame and a tool clamp block, the clamp block is fixed to the tool magazine frame with threaded screw holes, the tool magazine frame and the manipulator maintain a fixed relative position, and inputting the relative spatial position of the two into the control system can allow the manipulator to accurately locate the position where the tool needs to be changed.

[0010] The automatic tool changing execution end mechanism, during the tool changing operation, uses the cylinder to push the tool changing push rod to the left and compress the butterfly compression spring, the ball cone hole of the push rod enters the ball groove, and the small steel ball in the push rod produces an up and down displacement; then, the tool handle is pushed to the right to fit tightly against the push rod, and then the cylinder is slowly released, the butterfly spring is deformed and restored, and the push rod is pulled back into the spindle cavity while the tool handle is pushed to the right, the ball cone hole disengages from the ball groove, the upper space of the small steel ball is closed, moves downward, and clamps the tool handle head inward.

[0011] In the multi-axis robotic arm, the first axis structure of the base is connected to the second axis structure through the second axis base, the lower end of the second axis arm is connected to the second axis structure, the upper end of the second axis arm is connected to the third axis structure, the third axis structure and the fourth axis structure are connected through the fourth axis forearm, one end of the fifth axis wrist is connected to the fourth axis structure, the other end of the fifth axis wrist is connected to the fifth axis structure, and the machining spindle structure is connected to the fifth axis structure through the fifth axis head joint.

[0012] The beneficial effects of the present invention are mainly manifested in: the blade positioning and clamping device can firmly fix the engine blades and stabilize the workpiece during milling; the automatic tool changing device has a fast tool changing speed, high tool changing positioning accuracy, and a large storage capacity of tools in the tool magazine; the multi-axis robotic arm has a large working space and high flexibility, and multi-axis joint drive can realize the function of flexible processing of engine blades. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the clamping and positioning mechanism for blade surface processing.

[0014] Figure 2 It is a schematic diagram of the automatic tool changing magazine mechanism.

[0015] Figure 3 It is a schematic diagram of the automatic tool changing actuator mechanism.

[0016] Figure 4 It is a schematic diagram of the cross-section of the spindle mechanism.

[0017] Figure 5 It is the processing flow chart of the multi-degree-of-freedom milling device for compressor blades.

[0018] Among them, 1 is the secondary fixture base, 2 is the slider, 3 is the main fixture base, 4 is the tool magazine frame, 5 is the tool clamp block, 6 is the second axis base, 7 is the second axis arm, 8 is the fourth axis arm, 9 is the fifth axis wrist, 10 is the fifth axis head section, 11 is the cylinder, 12 is the butterfly spring, 13 is the tool changing push rod, 14 is the main axis, and 15 is the small steel ball. DETAILED DESCRIPTION

[0019] The present invention will be further described below in conjunction with the accompanying drawings.

[0020] Reference Figure 1 to Figure 5 , a multi-degree-of-freedom milling device for compressor blades, comprising a blade positioning and clamping device, an automatic tool changing device, and a multi-axis robotic arm; the blade positioning and clamping device comprises a blade tenon processing clamping and positioning mechanism and a blade surface processing clamping and positioning mechanism, which has a clamping position that can firmly fix the engine blade and has a reasonable shape, thereby ensuring the stability of the workpiece during the milling process and increasing the overall rigidity; the automatic tool changing device comprises an automatic tool changing magazine mechanism and an automatic tool changing execution end mechanism, which have the characteristics of fast tool changing speed, high tool changing positioning accuracy, a large storage capacity of tools in the magazine, and can realize rapid tool changing, thereby ensuring the continuity of the milling process and fully CNC automated processing; the multi-axis robotic arm comprises a first axis structure of the base, a second axis structure, a third axis structure, a fourth axis structure, a fifth axis structure, and a processing spindle structure. The multi-axis robotic arm has a large working space and high flexibility, and multiple axes are driven together to realize the function of flexible processing of engine blades. The present invention utilizes the advantages of automation and research foundation of traditional precision CNC machine tools, combines the flexibility of multi-axis rotation of industrial robots, and the advantages of high positioning accuracy, and designs a multi-degree-of-freedom robotic arm milling device with finishing as the main function, which can realize the processing of complex spatial surfaces of engine blades.

[0021] Furthermore, the blade tenon processing clamping and positioning mechanism adopts the method of wrapping with low melting point alloy. First, the blank and the low melting point alloy are melted and cast into a simple geometric shape. The blade casting and wrapping part is the main positioning part, which is mainly clamped up and down by the main clamp body to limit the movement of the workpiece in the Z axis; secondly, there is a positioning baffle on the main clamp base 3 to limit the movement of the workpiece in the X and Y axis directions. The upper and lower pressure blocks of the main clamp body are pressed to provide clamping force, which directly acts in the Z axis direction. The static friction force generated by the clamp body pressing the workpiece surface coincides with the main axial milling force generated by the tool.

[0022] The blade surface processing clamping and positioning mechanism, the special clamp component matches the shape of the blade tenon, the special component is fixed on the threaded holes of the upper pressure block and the secondary clamp base 1 with screws, and the shape of the special clamp component and the tenon directly limits the displacement of the workpiece Z and X axes; the extended baffles on both sides of the special component limit the displacement of the workpiece Y axis. The main clamp specifically provides the main clamping force, which coincides with the axial component of the milling force; the friction and extrusion force generated by the clamping force and the workpiece coincide with the main milling force; the auxiliary clamping mechanism is located at the other end of the workpiece to provide lateral clamping force.

[0023] The automatic tool changing tool magazine mechanism includes a tool magazine frame 4 and a tool clamp 5. The clamp is fixed to the tool magazine frame 4 with threaded screw holes. The tool magazine frame 4 and the manipulator maintain a fixed relative position. Inputting the relative spatial position of the two into the control system can allow the manipulator to accurately locate the position where the tool needs to be changed.

[0024] The automatic tool changing execution end mechanism, during the tool changing operation, uses the cylinder 11 to push the tool changing push rod 13 to the left and compress the butterfly spring 12, the ball cone hole of the push rod enters the ball groove, and the small steel ball 15 in the push rod produces an up and down displacement; then, the tool handle is pushed to the right to fit tightly against the push rod, and then the cylinder 11 is slowly released, the butterfly spring 12 is deformed and restored, and the push rod is pulled back into the spindle cavity while the tool handle is pushed to the right, the ball cone hole is disengaged from the ball groove, the upper end space of the small steel ball 15 is closed, and it moves downward to clamp the tool handle head inward.

[0025] In the multi-axis robotic arm, the first axis structure of the base is connected to the second axis structure through the second axis base 6, the lower end of the second axis arm 7 is connected to the second axis structure, the upper end of the second axis arm 7 is connected to the third axis structure, the third axis structure and the fourth axis structure are connected through the fourth axis forearm 8, one end of the fifth axis wrist 9 is connected to the fourth axis structure, the other end of the fifth axis wrist 9 is connected to the fifth axis structure, and the machining spindle structure is connected to the fifth axis structure through the fifth axis head section 10.

[0026] The motion process of the present invention is as follows: first, the processing part is the blade tenon, and the blank and the low-melting-point alloy are first melted and cast into a simple geometric shape. The slider 2 and the main clamp base 3 of the blade tenon processing clamping and positioning mechanism clamp the blade body, and the multi-axis robot clamps the milling tool to perform milling processing on the blade tenon. After the tenon processing is completed, the low-melting-point alloy is melted, and the blade forging blank is taken out for a second clamping and processing; the secondary clamping part is located at the tenon, which is clamped with a designed special clamp and laterally tightened with an auxiliary clamping mechanism; at the same time, the automatic tool changing device changes the tool, and the cylinder 11 pushes the tool changer inside the spindle The rod 13 is pushed outward, and the left end of the tool changing push rod 13 is disengaged from the small diameter cavity that restricts the small steel ball 15. The small steel ball 15 in the tapered hole of the tool changing push rod 13 can be displaced upward, and the clamping force of the small steel ball 15 on the tool handle disappears, so that the tool can be separated from the spindle 14; after the tool is changed, the new tool is pushed into the spindle 14, and the tool handle is stuck in the front end cavity of the tool changing push rod 13. The tool handle continues to be pushed into the spindle 14 to drive the tool changing push rod 13 to move back. The small steel ball 15 in the tapered hole of the tool changing push rod 13 is again restricted by the small diameter cavity of the spindle 14 to move inward, generating a clamping force on the tool handle, and finally completing the milling process of the blade surface.

[0027] The contents described in the embodiments of this specification are merely an enumeration of the implementation forms of the inventive concept. The protection scope of the present invention should not be regarded as limited to the specific forms described in the embodiments. The protection scope of the present invention also extends to equivalent technical means that can be conceived by those skilled in the art based on the inventive concept.

Claims

1. A multi-degree-of-freedom milling device for compressor blades, characterized in that: The multi-degree-of-freedom milling device includes a blade positioning clamping device, an automatic tool changing device and a multi-axis robotic arm; the blade positioning clamping device includes a blade tenon processing clamping and positioning mechanism and a blade surface processing clamping and positioning mechanism, which are used to fix the engine blade; the automatic tool changing device includes an automatic tool changing tool magazine mechanism and an automatic tool changing execution end mechanism; the multi-axis robotic arm includes a first axis structure of the base, a second axis structure, a third axis structure of the small arm, a fourth axis small arm structure, a fifth axis wrist structure and a processing spindle structure; The automatic tool changing tool magazine mechanism comprises a tool magazine frame and a tool clamping block, the clamping block is fixed to the tool magazine frame by a threaded screw hole, the tool magazine frame and the manipulator maintain a fixed relative position, and the relative spatial position of the two is input into the control system so that the manipulator can accurately locate the position where the tool needs to be changed; The automatic tool-changing execution end mechanism, when the tool is changed, uses the cylinder to push the tool-changing push rod to the left and compress the butterfly spring, so that the ball cone hole of the push rod enters the ball groove, and the small steel ball in the push rod moves up and down; then, the tool handle is pushed to the right to fit tightly with the push rod, and then the cylinder is slowly released, the butterfly spring is deformed and restored, and the push rod is pulled back into the spindle cavity while the tool handle is pushed to the right, the ball cone hole is separated from the ball groove, the space above the small steel ball is closed, and it moves downward to clamp the tool handle head inward; The blade tenon processing clamping and positioning mechanism adopts a low-melting-point alloy wrapping method. First, the blank and the low-melting-point alloy are melted and cast into a simple geometric shape. The blade casting and wrapping part is the positioning part, which is clamped up and down by the main clamp to limit the movement of the workpiece in the Z axis. Secondly, there is a positioning baffle on the main clamp base to limit the movement of the workpiece in the X and Y axis directions. The upper and lower pressure blocks of the main clamp are pressed to provide clamping force, and the clamping force directly acts in the Z axis direction. The static friction force generated by the clamp pressing the workpiece surface coincides with the main axial milling force generated by the tool. The blade surface processing clamping and positioning mechanism, the special clamp component is consistent with the shape of the blade tenon, the special clamp component is fixed on the threaded holes of the upper pressure block and the clamp base with screws, the shape of the special clamp component and the tenon directly limits the displacement of the workpiece Z and X axes; the extended baffles on both sides of the special component limit the displacement of the workpiece Y axis; the main clamp specifically provides the main clamping force, which coincides with the axial component of the milling force; the friction force and extrusion force generated by the clamping force and the workpiece coincide with the main milling force; the auxiliary clamping mechanism is located at the other end of the workpiece to provide lateral clamping force.

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