阅读说明：本技术 一种带冠叶轮用电火花造型方法 (Electric spark modeling method for shrouded impeller ) 是由 吴江 曹春晓 严小琳 于 2021-07-20 设计创作，主要内容包括：本发明公开了一种带冠叶轮用电火花造型方法,涉及电火花加工技术领域,包括如下步骤：安装工件、孔位对准、锥形孔加工、圆柱形孔加工以及加工完毕。本发明通过在调节机构上设置工具电极组件,电缸的输出端复位回程后,工作液的流向全部变为自电极一上的斜流孔斜向下冲出,冲入圆柱形孔内的单侧方向,又经孔内电极一的下方区域后于电极一的另一侧冲出,该流向能够有效排出位于较深的圆柱形孔内电蚀产物,进而避免出现拉弧或短路现象,保证气膜孔内的孔壁质量；通过设置机械手臂及调节机构,可以实现避开工件的斜向干涉部位,保证工件叶身和叶冠相接处的待加工位置顺利进行气膜孔的加工。(The invention discloses an electric spark modeling method for a shrouded impeller, which relates to the technical field of electric spark machining and comprises the following steps: installing a workpiece, aligning hole positions, processing a conical hole, processing a cylindrical hole and finishing the processing. According to the invention, the tool electrode assembly is arranged on the adjusting mechanism, after the output end of the electric cylinder returns to the reset position, the flow direction of the working solution is changed into that the working solution is obliquely downwards punched out from the oblique flow hole on the first electrode, and is punched into the single-side direction of the cylindrical hole, and is punched out from the other side of the first electrode after passing through the lower area of the first electrode in the hole, and the flow direction can effectively discharge the electric corrosion products in the deeper cylindrical hole, so that the phenomena of arc discharge or short circuit are avoided, and the quality of the hole wall in the gas film hole is ensured; through setting up robotic arm and adjustment mechanism, can realize keeping away from the slant of work piece and interfere the position, guarantee that the processing position of waiting of work piece blade body and blade crown department of meeting carries out the processing in air film hole smoothly.)

1. The spark modeling method for the shrouded impeller is characterized by comprising the following steps of:

s1: installing a workpiece: mounting a workpiece to be machined on a workbench of an electric spark machine tool, and aligning and fixing;

s2: hole position alignment: the adjusting mechanism (3) is controlled to do five-axis motion by a mechanical arm (2) arranged on the base (1), so that the lower end of a tool electrode assembly (4) arranged at the end part of the adjusting mechanism (3) is arranged at a hole position to be processed between a blade crown and a blade root on a workpiece;

s3: processing a taper hole: pumping working fluid for electric spark machining into the adjusting mechanism (3) through a fluid supply pipeline (6) by a fluid supply pump (5), driving the tool electrode assembly (4) by the adjusting mechanism (3) to complete the modeling and machining of the conical hole on the workpiece, simultaneously flushing the working fluid from the lower end of the tool electrode assembly (4) through two sides of the conical hole, and discharging an electroerosion product;

s4: machining a cylindrical hole: the adjusting mechanism (3) drives the tool electrode assembly (4) to finish the modeling processing of the cylindrical hole on the workpiece, and meanwhile, the working solution is obliquely and downwards flushed into one side of the cylindrical hole from the tool electrode assembly (4), is flushed out from the other side of the cylindrical hole after passing through the lower part of the tool electrode assembly (4), and discharges a deeper electrolytic corrosion product in the cylindrical hole;

s5: and (3) finishing the processing: and after all the machining holes on the workpiece are finished in sequence, closing the liquid supply pump (5) and unloading the machined workpiece.

2. The electric spark modeling method for the shrouded impeller of claim 1 wherein: the adjusting mechanism (3) comprises an electric cylinder (31), a mounting part (32) and a rotating blade (33), the mounting part (32) is mounted at the end part of the mechanical arm (2), the upper end of the mounting part (32) is communicated with the liquid supply pipeline (6), a T-shaped isolation plate (34) is arranged in the mounting part (32), the electric cylinder (31) is arranged at the lower end of the isolation plate (34), the output end of the electric cylinder (31) is hinged with a mandril (35), the other end of the ejector rod (35) is hinged with a rotating ring (36), the rotating ring (36) is rotatably arranged on the tool electrode assembly (4), a liquid spraying head (37) is arranged above the isolating plate (34) in the mounting part (32), the rotary blade (33) is rotatably mounted in the mounting part (32), and the lower end of the rotary blade (33) is fixed with the tool electrode assembly (4) through a perforated connection plate (38) in the same shaft mode.

3. The electric spark modeling method for the shrouded impeller of claim 2 wherein: the cavity above the partition plate (34) in the installation part (32) is communicated with the liquid supply pipeline (6), and the rotating blade (33) is arranged in the cavity on the left side of the partition plate (34).

4. The electric spark modeling method for the shrouded impeller of claim 2 wherein: the liquid spraying head (37) is obliquely installed in the installation part (32), and an outlet of the liquid spraying head (37) is matched with the rotating blade (33).

5. The electric spark modeling method for the shrouded impeller of claim 1 wherein: the tool electrode assembly (4) comprises a first electrode (41), a second electrode (42) and a plugging ball (43), wherein the first electrode (41) is hollow, the upper end of the first electrode is fixed with the same shaft of the perforated connecting plate (38), the first electrode (41) is provided with two symmetrically-arranged sliding grooves (44), the first electrode (41) is further provided with a plurality of uniformly-distributed oblique flow holes (45) in the vertical direction, a perforated fixing plate (46) is arranged inside the first electrode (41), the lower end of the first electrode (41) is provided with a vertical flow hole (47), the plugging ball (43) is tightly abutted against the lower end of the perforated fixing plate (46) through a spring (48), the lower end of the plugging ball (43) is tightly abutted against the vertical flow hole (47), the lower part of the first electrode (41) is further provided with two symmetrically-arranged pushing balls (49) in a sliding manner on two sides of the plugging ball (43), and the second electrode (42) is arranged in the sliding manner in the sliding grooves (44), the upper end of the second electrode (42) is connected with the rotating ring (36) in a rotating way in the same axis.

6. The electric spark modeling method for the shrouded impeller of claim 5 wherein: the two push balls (49) are matched with the second electrode (42) in the vertical direction.

7. The electric spark modeling method for the shrouded impeller of claim 5 wherein: the diameter of the blocking ball (43) is larger than the aperture of the vertical flow hole (47) and smaller than the inner diameter of the first electrode (41).

8. The electric spark modeling method for the shrouded impeller of claim 2 wherein: and the output end of the electric cylinder (31) is in a fully extended state, and the height of the lower end surface of the second electrode (42) is not higher than that of the lower end surface of the first electrode (41).

Technical Field

The invention relates to the technical field of electric spark machining, in particular to an electric spark modeling method for a shrouded impeller.

Background

The internal turbine blade of aeroengine operating condition is very abominable, it is high-speed rotatory under the impact of high pressure corrosivity gas, it cools off mainly to rely on the cooling air film hole that the terminal surface was seted up in the structure, prior art adopts the electric spark machining technique to carry out the micropore processing in cooling air film hole to the blade usually, be about to the work piece submergence is positioned in the electric spark machining working solution, utilize rotatory integral type electrode direct processing bell mouth and cylindrical hole on the machined surface, simultaneously through the ultrasonic vibration auxiliary assembly of integration setting, discharge the electroerosion product that produces in the electric spark machining process.

However, I find that the prior art still has certain disadvantages in the process of shaping and processing the shrouded impeller blade for a long time: firstly, the gas film hole is tiny in structure and deep in depth, before the gas film hole on the end face is completely opened, ultrasonic vibration can only be matched with working liquid to bring out an electric corrosion product on the side of the integrated electrode close to the hole opening, and the electric corrosion product on the lower part of the integrated electrode with a large height-diameter ratio in the hole cannot be effectively removed, so that the phenomena of arc discharge or short circuit occur, and the quality of the hole wall of the lower part in the gas film hole is influenced; second, because the blade body extension length of the relative blade of shroud impeller's blade shroud is longer, and the two department of meeting possesses certain structure angle, leads to the integral type electrode to have the interference phenomenon when processing this department, and the interference air film hole that processes out has the air current to interact with other cooling air film holes, leads to the cooling effect of blade to remain to promote.

Disclosure of Invention

The invention aims to provide an electric spark modeling method for a shrouded impeller, which aims to overcome the defects caused in the prior art.

An electric spark molding method for a shrouded impeller comprises the following steps:

s1: installing a workpiece: mounting a workpiece to be machined on a workbench of an electric spark machine tool, and aligning and fixing;

s2: hole position alignment: the machining tool is arranged at a hole position to be machined between a blade crown and a blade root which are arranged on a workpiece;

s3: processing a taper hole: pumping working fluid for electric spark machining into the adjusting mechanism through a fluid supply pipeline by a fluid supply pump, driving the tool electrode assembly 4 by the adjusting mechanism to complete the modeling and machining of the conical hole on the workpiece, simultaneously flushing the working fluid from the lower end of the tool electrode assembly through two sides of the conical hole, and discharging an electroerosion product;

s4: machining a cylindrical hole: the adjusting mechanism drives the tool electrode assembly to finish the modeling processing of the cylindrical hole on the workpiece, and meanwhile, the working solution obliquely downwards rushes into one side of the cylindrical hole from the tool electrode assembly, rushes out from the other side of the cylindrical hole after passing through the lower part of the tool electrode assembly, and discharges the deep electro-corrosion product in the cylindrical hole;

s5: and (3) finishing the processing: and after all the machining holes on the workpiece are finished in sequence, closing the liquid supply pump 5 and unloading the machined workpiece.

Preferably, adjustment mechanism includes electric jar, installation department and rotating vane, the installation department is installed in robotic arm's tip, and the upper end and the feed liquor pipeline of installation department are linked together, are provided with the division board of "T" shape in the installation department, the electricity jar is installed in the lower extreme of division board, and the output of electricity jar articulates there is the ejector pin, the other end of ejector pin articulates there is the change, the change rotates and sets up on instrument electrode subassembly, installs the hydrojet head in the top of division board in the installation department, rotating vane rotates and installs in the installation department, and rotating vane's lower extreme is through foraminiferous fishplate bar and instrument electrode subassembly looks coaxial fastening.

Preferably, a cavity above the partition plate in the mounting part is communicated with the liquid supply pipeline, and the rotating blade is arranged in a cavity on the left side of the partition plate.

Preferably, the liquid spraying head is obliquely installed in the installation part, and an outlet of the liquid spraying head is matched with the rotating blade.

Preferably, the tool electrode assembly comprises a first electrode, a second electrode and a plugging ball, the first electrode is hollow, the upper end of the first electrode is coaxially fixed with the perforated connecting plate, two symmetrically-arranged sliding grooves are formed in the first electrode, a plurality of uniformly-distributed oblique flow holes are formed in the first electrode in the vertical direction, a perforated fixing plate is arranged inside the first electrode, a vertical flow hole is formed in the lower end of the first electrode, the plugging ball is tightly abutted to the lower end of the perforated fixing plate through a spring, the lower end of the plugging ball is tightly abutted to the vertical flow hole, two symmetrically-arranged pushing balls are further slidably arranged on the lower portion of the first electrode on two sides of the plugging ball, the second electrode is slidably arranged in the sliding grooves, and the upper end of the second electrode is rotatably connected with the same shaft of the rotating ring.

Preferably, two of the pushing balls are matched with the electrode in the vertical direction.

Preferably, the diameter of the plugging ball is larger than the aperture of the vertical flow hole and smaller than the inner diameter of the first electrode.

Preferably, the output end of the electric cylinder is in a fully extended state, and the height of the lower end face of the second electrode is not higher than that of the lower end face of the first electrode.

The invention has the advantages that: (1) the tool electrode assembly is arranged on the adjusting mechanism, the output end of the electric cylinder drives the electrode II to slide on the electrode I to the lowest end through the ejector rod, the vertical flow hole arranged at the lower end of the electrode I is opened through pushing the two ejector push balls, the high-pressure working fluid is flushed out from two sides of the tool electrode assembly in the conical hole after being flushed out from the vertical flow hole, and then an electric corrosion product generated in the machining process is brought out;

(2) through setting up robotic arm and adjustment mechanism, drive electrode two earlier and remove to the lower extreme of electrode one, the robotic arm of five-axis motion is cooperated, the slant that can realize avoiding the work piece is interfered the position, take first to carry out the bell mouth processing to blade body and blade shroud junction on the work piece, cylindrical hole of bell mouth lower extreme is processed by the less electrode one of cross-section relative dimension again, electrode two that lie in the top this moment can not cause the cylinder hole molding to interfere, guarantee that the processing position of treating of work piece blade body and blade shroud junction carries out the processing in gas film hole smoothly.

Drawings

FIG. 1 is a flow chart of the present invention.

Fig. 2 is a schematic view of the present invention in a state of machining a tapered hole.

Fig. 3 is an enlarged view of a structure at a in fig. 2.

Fig. 4 is a schematic view of the state of the present invention when a cylindrical hole is machined.

Fig. 5 is an enlarged view of the structure at B in fig. 4.

Fig. 6 is a view showing a structure of a work in the present invention.

Fig. 7 is a schematic view showing a state in which the working fluid is obliquely and downwardly flushed out from the tool electrode assembly in the present invention.

Fig. 8 is an interference representation of a prior art integral electrode in machining an interference hole.

FIG. 9 is a schematic view of the process of machining interference holes according to the present invention.

The device comprises a base 1, a mechanical arm 2, an adjusting mechanism 3, a tool electrode assembly 4, a liquid supply pump 5, a liquid supply pipeline 6, an electric cylinder 31, a mounting part 32, a rotating blade 33, a separation plate 34, a mandril 35, a rotating ring 36, a liquid spray head 37, a perforated connection plate 38, a first electrode 41, a second electrode 42, a blocking ball 43, a chute 44, an inclined flow hole 45, a perforated fixing plate 46, a vertical flow hole 47, a spring 48 and a pushing ball 49.

Detailed Description

In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further described with the specific embodiments.

As shown in fig. 1 to 9, a spark modeling method for a shrouded impeller includes the following steps:

s1: installing a workpiece: mounting a workpiece to be machined on a workbench of an electric spark machine tool, and aligning and fixing;

s2: hole position alignment: controlling an adjusting mechanism 3 to perform five-axis motion by a mechanical arm 2 arranged on a base 1, so that the lower end of a tool electrode assembly 4 arranged at the end part of the adjusting mechanism 3 is arranged at a hole position to be processed between a blade crown and a blade root on a workpiece;

s3: processing a taper hole: pumping working fluid for electric spark machining into the adjusting mechanism 3 through a fluid supply pipeline 6 by a fluid supply pump 5, driving the tool electrode assembly 4 by the adjusting mechanism 3 to complete the shaping and machining of the conical hole on the workpiece, and simultaneously flushing the working fluid from the lower end of the tool electrode assembly 4 through two sides of the conical hole and discharging an electroerosion product;

s4: machining a cylindrical hole: the adjusting mechanism 3 drives the tool electrode assembly 4 to finish the modeling processing of the cylindrical hole on the workpiece, and meanwhile, the working solution obliquely downwards rushes into one side of the cylindrical hole from the tool electrode assembly 4, rushes out from the other side of the cylindrical hole after passing through the lower part of the tool electrode assembly 4, and discharges a deep electrolytic corrosion product in the cylindrical hole;

s5: and (3) finishing the processing: and after all the machining holes on the workpiece are finished in sequence, closing the liquid supply pump 5 and unloading the machined workpiece.

In this embodiment, the adjusting mechanism 3 includes an electric cylinder 31, an installation portion 32 and a rotary blade 33, the installation portion 32 is installed at the end portion of the mechanical arm 2, the upper end of the installation portion 32 is communicated with the liquid supply pipe 6, a T-shaped isolation plate 34 is provided in the installation portion 32, the electric cylinder 31 is installed at the lower end of the isolation plate 34, the output end of the electric cylinder 31 is hinged to a push rod 35, the other end of the push rod 35 is hinged to a rotary ring 36, the rotary ring 36 is rotatably provided on the tool electrode assembly 4, a liquid spray head 37 is installed above the isolation plate 34 in the installation portion 32, the rotary blade 33 is rotatably installed in the installation portion 32, and the lower end of the rotary blade 33 is fixed with the tool electrode assembly 4 through a perforated connection plate 38.

In this embodiment, the chamber of the mounting portion 32 above the partition 34 is connected to the liquid supply duct 6, and the rotary vane 33 is disposed in the left chamber of the partition 34.

In this embodiment, the liquid ejecting head 37 is installed obliquely in the installation portion 32, and an outlet of the liquid ejecting head 37 is engaged with the rotary blade 33.

In this embodiment, the tool electrode assembly 4 includes a first electrode 41, a second electrode 42, and a sealing ball 43, the first electrode 41 is hollow, and the upper end of the first electrode is coaxially fixed to the perforated connection plate 38, the first electrode 41 is provided with two symmetrically arranged sliding grooves 44, the first electrode 41 is further provided with a plurality of uniformly distributed diagonal flow holes 45 in the vertical direction, the first electrode 41 is internally provided with a perforated fixing plate 46, the lower end of the first electrode 41 is provided with a vertical flow hole 47, the sealing ball 43 is tightly abutted to the lower end of the perforated fixing plate 46 through a spring 48, the lower end of the sealing ball 43 is tightly abutted to the vertical flow hole 47, the lower portion of the first electrode 41 is further slidably provided with two symmetrically arranged pushing balls 49 at two sides of the sealing ball 43, the second electrode 42 is slidably arranged in the sliding grooves 44, and the upper end of the second electrode 42 is rotatably connected to the same shaft of the swivel 36.

It should be noted that the end surface of the outer edge of the first electrode 41 in the vertical direction is circular.

In this embodiment, two of the pushing balls 49 are vertically matched with the second electrode 42.

In this embodiment, the diameter of the plugging ball 43 is larger than the diameter of the vertical flow hole 47 and smaller than the inner diameter of the first electrode 41.

In addition, the output end of the electric cylinder 31 is in a fully extended state, and the height of the lower end face of the electrode II 42 is not higher than that of the lower end face of the electrode I41.

The working process and principle are as follows: when the invention is used, a workpiece is installed, hole position alignment, taper hole machining, cylindrical hole machining and unloading operation after machining are carried out in sequence according to the working procedures, in the hole shaping machining process after the hole positions are aligned, firstly, the workpiece is connected with the anode of an electric spark machining power supply, a tool electrode assembly 4 is connected with the cathode of the electric spark machining power supply, then, an electric cylinder 31 is started to enable the output end of the electric cylinder to extend out, an electrode II 42 is driven by an ejector rod 35 to slide on an electrode I41 to the lowest end, at the moment, the electrode II 42 pushes two pushing balls 49 horizontally arranged at the lower end of the electrode I41 in a sliding groove 44, under the action of the two symmetrically arranged pushing balls 49, a blocking ball 43 moves upwards in the electrode I41, at the moment, a spring 48 is stressed and compressed, and a vertical flow hole 47 arranged at the lower end of the electrode I41 is opened;

then the liquid supply pump 5 is started, the electric spark machining working liquid is supplied to the cavity above the partition plate 34 in the installation part 32 at high pressure through the liquid supply pipeline 6, the working liquid passes through the obliquely arranged liquid spraying head 37 and then washes and rotates the end face of the rotating blade 33 installed in the installation part 32, so as to drive the tool electrode assembly 4 at the lower end to synchronously and continuously rotate, the rotating tool electrode assembly 4 can enable the end face thereof to be uniformly worn, the deflection caused by the reverse acting force of the high-pressure and high-speed working liquid is avoided, most of the working liquid flowing to the electrode I41 through the perforated connecting plate 38 is flushed from the vertical flow hole 47 with a larger aperture, after the electric spark machining power supply is started, the electric spark machining of the conical hole is started, the working liquid is flushed from the two sides of the tool electrode assembly 4 in the conical hole, and then the electric erosion product generated in the machining process is carried out, and in the process, because the electrode II 42 moves to the lowest end of the electrode I41, the mechanical arm 2 which is matched with five-axis motion can avoid the oblique interference part of the workpiece, so that the air film hole is processed at the position to be processed at the joint of the blade body and the blade shroud of the workpiece;

after the machining of the conical hole is finished, the electric cylinder 31 is started again to enable the output end of the electric cylinder to return to the return stroke, the electrode II 42 slides on the electrode I41 to the highest position under the pulling action of the ejector rod 35, at the moment, two ejector balls 49 ejected by the electrode II 42 are reset under the pushing action of a spring 48, the blocking balls 43 block the vertical flow holes 47 formed in the lower end of the electrode I41 again, the flow direction of the high-pressure working fluid is changed into that the high-pressure working fluid is ejected downwards from the inclined flow holes 45 on the electrode I41 in an inclined mode, when the inner cylindrical hole is machined, the working fluid ejected downwards from the rotating electrode I41 in an inclined mode can be ejected into the single side direction of the cylindrical hole and then passes through the lower area of the electrode I41 in the hole to be ejected out from the other side of the electrode I41, the flow direction can effectively discharge electric corrosion products in the deeper cylindrical hole, the phenomenon of arc drawing or short circuit is avoided, the quality of the hole wall in the air film hole is guaranteed, and meanwhile, the electrode I41 with the smaller cross section, the second electrode 42 which is positioned at the uppermost end does not cause the interference of the cylindrical hole shape, and the smooth processing of the air film hole is ensured at the position to be processed at the joint of the blade body and the blade shroud of the workpiece.

Based on the above, the invention arranges the tool electrode assembly 4 on the adjusting mechanism 3, the output end of the electric cylinder 31 drives the second electrode 42 to slide on the first electrode 41 to the lowest end through the mandril 35, the vertical flow hole 47 arranged at the lower end of the electrode I41 is opened by pushing the two pushing balls 49, the high-pressure working fluid is punched out from the two sides of the tool electrode assembly 4 in the conical hole after being punched out from the vertical flow hole 47, then carrying out the electric corrosion products generated in the processing process, after the output end of the electric cylinder 31 returns, the flow direction of the working solution is changed into that the working solution is obliquely downwards flushed out from the oblique flow hole 45 on the first electrode 41, is flushed into the single-side direction of the cylindrical hole, passes through the lower area of the first electrode 41 in the hole and then is flushed out from the other side of the first electrode 41, the flow direction can effectively discharge the electric corrosion products in the deeper cylindrical hole, thereby avoiding the phenomena of arc discharge or short circuit and ensuring the quality of the hole wall in the gas film hole;

through setting up robotic arm 2 and adjustment mechanism 3, drive electrode two 42 earlier and remove to the lower extreme of electrode one 41, cooperation five-axis motion robotic arm 2 can realize avoiding the slant of work piece and interfering the position, take first to carry out the bell mouth processing to blade body and blade shroud junction on the work piece, cylindrical hole of bell mouth lower extreme is processed by electrode one 41 that the relative size in cross-section is less again, electrode two 42 that are located the top this moment can not cause the interference of cylinder hole molding, guarantee that the position of treating of work piece blade body and blade shroud junction carries out the processing in gas film hole smoothly.

It will be appreciated by those skilled in the art that the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The embodiments disclosed above are therefore to be considered in all respects as illustrative and not restrictive. All changes which come within the scope of or equivalence to the invention are intended to be embraced therein.