CN110842307B - Electrochemical machining tool for complex inner wall structure with poor accessibility - Google Patents

Electrochemical machining tool for complex inner wall structure with poor accessibility Download PDF

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Publication number
CN110842307B
CN110842307B CN201911155381.XA CN201911155381A CN110842307B CN 110842307 B CN110842307 B CN 110842307B CN 201911155381 A CN201911155381 A CN 201911155381A CN 110842307 B CN110842307 B CN 110842307B
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cathode
deformation
hose
rod
processing
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CN110842307A (en
Inventor
张聚臣
李兴林
陈顺华
许吉敏
张克旭
付宇帆
胡士林
杨秀军
葛灵宇
常伟杰
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Hefei University of Technology
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Hefei University of Technology
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B23MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23HWORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
    • B23H3/00Electrochemical machining, i.e. removing metal by passing current between an electrode and a workpiece in the presence of an electrolyte
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B23MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23HWORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
    • B23H3/00Electrochemical machining, i.e. removing metal by passing current between an electrode and a workpiece in the presence of an electrolyte
    • B23H3/04Electrodes specially adapted therefor or their manufacture

Abstract

The invention discloses an electrochemical machining tool for machining and forming a complex inner wall with poor accessibility, and belongs to the field of electrochemical machining. Comprises a cathode mechanism, a deformation mechanism and a connecting mechanism; the cathode mechanism comprises a cathode body, and electrolyte outlets are uniformly distributed on the working surface of the cathode body; the deformation mechanism comprises a deformation rod and a hose with two sealed ends, the deformation rod is coaxially arranged in the sealed hose, and the deformation rod is made of shape memory alloy; one end of the hose is communicated with the cathode body and the electrolyte pipeline, and the other end of the hose is communicated with the liquid inlet pipe and the first connecting rod; the processing operation is divided into three stages: 1. introducing high-temperature electrolyte into the deformation mechanism, and enabling the deformation rod to be in a stretched state and enter an inner cavity of a processed workpiece; 2. introducing normal-temperature electrolyte, enabling the deformation rod to be in a bending state, and enabling the cathode body to reach an area to be processed for processing; 3. and introducing high-temperature electrolyte, straightening the deformed rod and withdrawing the deformed rod out of the processing area. The invention is suitable for processing the workpiece with the complex inner wall with poor accessibility, and has simple and effective deformation control and high processing efficiency.

Description

Electrochemical machining tool for complex inner wall structure with poor accessibility
Technical Field
The invention belongs to the technical field of electrolytic machining, and particularly relates to an electrolytic machining tool for a complex inner wall structure with poor accessibility.
Background
Electrochemical machining is a modern machining method for machining and shaping workpieces by utilizing the principle of electrochemical anodic dissolution of metal in electrolyte, and is non-contact machining. The method has the advantages of wide processing range, high processing efficiency, good processing surface quality, no tool loss, no mechanical cutting force, one-time forming and capability of obtaining complex geometric shapes, and is a processing method with special function in the mechanical manufacturing industry.
With the development of manufacturing industry in the twenty-first century, the mechanical field has higher level requirements on materials and structures of workpieces, a large number of high-hardness and high-strength metal materials which are difficult to process are applied, and more products adopt complex structures with excellent performance. Improvements in materials and structure have improved product performance, but have also presented significant challenges to the machine manufacturing industry. Firstly, the difficult processing property of the material provides great challenge for the traditional processing method, the common cutter can not process due to the high hardness of the material, and the electrolytic processing has the characteristics of no influence of the hardness of the material, good processing surface quality of the workpiece, no cutting force and the like, and is particularly suitable for processing the difficult-to-process material.
Secondly, for some complex parts (such as integral components widely applied to the field of aerospace), the internal structure is complicated, the channel is narrow and twisted, the accessibility of the cutter processing is poor, and the workpiece material is difficult to cut. The existing processing method for the complex inner wall with poor accessibility mainly comprises the following steps: electric spark machining, multi-axis linkage machining, additive manufacturing technology and the like. The electric spark machining can machine a complex wall surface with poor accessibility, but has the defects of low long-term efficiency of the electric spark machining, difficult electrode manufacturing, difficult control of machining precision and the like; the multi-axis linkage machining has the characteristics of high machining precision, shortened production process chain and simplified production management, but the multi-axis linkage machining has the defects of abstract numerical control programming, difficult operation, difficult tool radius compensation, complex machine tool structure and high cost, and still has insufficient machining accessibility; the additive manufacturing technology manufactures parts with any complex shapes, but the surface quality of the workpiece machined by the additive manufacturing technology is poor, and the precision is low. Therefore, a new complex inner wall processing device for poor accessibility is urgently required.
Disclosure of Invention
The invention provides an electrochemical machining tool aiming at a complex inner wall structure with poor accessibility, aiming at realizing that a cathode of the electrochemical machining tool reaches a complex inner wall position with poor accessibility to machine.
An electrochemical machining tool aiming at a complex inner wall structure with poor accessibility comprises a cathode mechanism 4, a deformation mechanism 3 and a connecting mechanism 2;
the cathode mechanism 4 comprises a cathode body 43 with a hollow cavity, and electrolyte outlets 42 are uniformly distributed on a working surface 42 of the cathode body 43;
the deformation mechanism 3 comprises a deformation rod 31 and a hose 32 with two sealed ends, the deformation rod 31 is coaxially and fixedly arranged in the sealed hose 32, and the deformation rod 31 is made of shape memory alloy; one end of the hose 32 is communicated with the cathode body 43 through more than two communicating pipes; the other end of the hose 32 is communicated with more than two liquid inlet pipes 37;
in the preparation processing stage, high-temperature electrolyte is introduced into the hose 32 of the deformation mechanism, and the deformation rod 31 is in a high-temperature phase straightening state, so that an electrochemical processing tool enters an inner cavity of a processed workpiece;
in the processing stage, normal-temperature electrolyte is introduced into the hose 32 of the deformation mechanism, the electrolyte is introduced into the cathode body 43 through the hose 32, the deformation rod 31 is in a low-temperature phase bending state, and the cathode body 43 reaches a region to be processed and is processed according to a set processing gap;
and after the processing is finished, introducing high-temperature electrolyte into the hose 32 of the deformation mechanism, and enabling the deformation rod 31 to exit from the processing area in a straightening state.
The technical scheme for further limiting is as follows:
a plurality of horizontal slit-shaped electrolyte outlets 42 are uniformly distributed on the working surface 42 of the cathode body 43.
The width of the seam of the electrolyte outlet 42 is 1-2 mm, and the length of the seam is 10-12 mm.
The cathode body 43 is a hollow cube, one side surface is a working surface 42, and the shape of the working surface 42 is matched with the shape of a surface to be processed of a processed workpiece; the other opposite side surface is communicated with more than two communicating pipes.
An upper end cover 33 is arranged at one end of the hose 32, and a lower end cover 34 is arranged at the other end of the hose 32, so that the hose 32 forms a hose with two sealed ends; the middle part of the outer side of the lower end cover 34 is fixedly connected with the cathode body 43 through the second connecting rod 22, and the middle part of the outer side of the upper end cover 33 is connected with one end of the first connecting rod 21.
The beneficial technical effects of the invention are embodied in the following aspects:
1. the electrochemical machining tool can reach a complex inner wall area which is difficult to reach by a conventional machining tool for machining, and the machining accessibility of the machining tool is greatly improved. The electrochemical machining tool adopts the shape memory alloy with the two-way memory effect as the deformation rod, and the cathode of the tool can reach the complex inner wall area with poor accessibility to complete electrochemical machining and forming through temperature control deformation.
2. The electrolytic machining tool is simple, quick and effective to control. The electrochemical machining tool is deformed by changing the temperature of the deformation rod, the electrochemical machining tool can be deformed by showing different temperature phases when the temperature of the deformation rod is changed by controlling the temperature of the electrolyte, and the electrochemical machining tool is not machined when high-temperature electrolyte is introduced, so that the electrochemical machining tool is simple, quick and effective to control.
3. The electrochemical machining tool has a high surface forming rule with high machining efficiency for machining the complex inner wall with poor accessibility. On one hand, the electrochemical machining tool is an electrochemical machining tool, and the electrochemical machining technology has the characteristics of high efficiency, one-time forming and the like, so that the electrochemical machining tool has higher machining efficiency. On the other hand, the tool cathode of the electrochemical machining tool is a forming cathode with a hollow thin-wall structure, the front end face of the tool cathode is designed according to the complex molded surface of the machined wall surface, and the complex shape of the front end face of the tool cathode can be 'copied' to a workpiece through a series of narrow-slit electrolyte outlets on the front end face, so that the electrochemical machining tool has a good surface forming rule.
4. Compared with the existing processing method of the complex wall surface with poor accessibility, the invention has the advantages of simple device structure, wide processing range, almost all conductive materials processing, no limitation of the strength and hardness of the materials, no mechanical cutting force and good processing surface quality.
Drawings
FIG. 1 is a schematic diagram of the present invention.
Fig. 2 is a structural sectional view of the present invention.
Fig. 3 is a view showing a state of use of the present invention for machining an annular groove.
FIG. 4 is a process flow diagram for machining an annular groove in accordance with the present invention.
FIG. 5 is a diagram of the present invention used for processing the blind hole of the variable cross-section pipeline.
FIG. 6 is a flow chart of the present invention for processing blind holes of variable cross-section pipes.
The sequence numbers in the above figures illustrate: the device comprises a feeding mechanism 1, a connecting mechanism 2, a first connecting rod 21, a second connecting pipe 22, a deformation mechanism 3, a deformation rod 31, a hose 32, an upper end cover 33, a lower end cover 34, a hose clamp 35, a liquid inlet pipe 37, a pipe joint 38, a cathode mechanism 4, a working surface 41, an electrolyte outlet 42, a cathode body 43, a workpiece 5 to be processed and an electrolyte temperature control device 6.
Detailed description of the preferred embodiments
The present invention will now be described in detail by way of specific embodiments with reference to the accompanying drawings.
Example 1
Referring to fig. 3, an electrochemical machining tool for a complex inner wall structure having poor accessibility includes a cathode mechanism 4, a deforming mechanism 3, and a connecting mechanism 2.
Referring to fig. 1 and 2, the cathode mechanism 4 includes a cathode body 43 having a hollow cavity, the cathode body 43 is a hollow cube, one side surface is a working surface 41, and the shape of the working surface 41 matches with the shape of the surface to be processed of the workpiece. A plurality of horizontal slit-shaped electrolyte outlets 42 are uniformly distributed on the working surface 41 of the cathode body 43. The slit width of the electrolyte outlet 42 is 1mm, and the slit length is 10 mm.
Referring to fig. 2, the deformation mechanism 3 comprises a deformation rod 31 and a hose 32 with two sealed ends, the deformation rod 31 is coaxially and fixedly installed in the sealed hose 32, and the deformation rod 31 is made of shape memory alloy. An upper end cap 33 is fixedly mounted on one end of the hose 32, and a lower end cap 34 is fixedly mounted on the other end of the hose 32, so that the hose 32 forms a hose with two sealed ends. The lower end cap 34 is fixedly connected to the cathode body 43 through the second connecting rod 22 at the outer middle portion thereof, and the upper end cap 33 is connected to one end of the first connecting rod 21 at the outer middle portion thereof. The upper end cover of the hose 32 is connected to four liquid inlet pipes 37 through pipe joints 38, and the lower end cover 34 of the hose is connected to the cathode body 43 through four communicating pipes.
Referring to fig. 3, the workpiece is a double-walled pipe (engine case), and the groove grooves of the inner surface (engine case) of the double-walled pipe are electrolytically machined using the electrolytic machining tool of the present invention.
Referring to fig. 4, the specific processing operation steps are as follows:
firstly, the electrochemical machining tool is fixedly connected to the lower end of a first connecting rod 21 through threads in the middle of an upper end cover 32, the upper end of the first connecting rod 21 is connected with a main shaft of a feeding system 1, and the first connecting rod 21 is connected with the cathode of an electrochemical machining power supply through a power clamp.
And step two, mounting the processed workpiece 5 on a workbench, and connecting the processed workpiece 5 with the anode of the electrochemical machining power supply.
Step three, electrolyte with the temperature of 70 ℃ is introduced, the deformation mechanism 3 is in a straightening state, and the feeding system 1 performs feeding motion to drive an electrochemical machining tool to enter a complex inner wall area with poor accessibility of a machined workpiece 5; then normal temperature electrolyte with the temperature of 25 ℃ is introduced, the deformation mechanism 3 is in a bending state, the tool cathode 4 reaches the initial processing position, and the processing gap is adjusted.
And step four, continuously supplying normal-temperature electrolyte at the temperature of 25 ℃, switching on an electrolytic machining power supply, and driving the electrolytic machining tool to perform feeding motion under the driving of the feeding system 1 to perform electrolytic machining.
And step five, when the processing of the concave ring groove is finished, disconnecting the electrolytic processing power supply, introducing high-temperature electrolyte at the temperature of 70 ℃, enabling the deformation mechanism 3 to be in a high-temperature phase straightening state, driving the electrolytic processing tool to exit from the processing area by the feeding system, stopping supplying the electrolyte, and finishing the one-time forming processing of the complex inner wall with poor accessibility.
Example 2
Referring to fig. 5, the workpiece 5 is a variable cross-section pipe, and blind holes are machined on the inner wall of the variable cross-section pipe by using the electrochemical machining tool of the invention.
Referring to fig. 6, the specific operation steps are as follows:
firstly, the electrochemical machining tool is fixedly connected to the lower end of a first connecting rod 21 through threads in the middle of an upper end cover 32, the upper end of the first connecting rod 21 is connected with a main shaft of a feeding system 1, and the first connecting rod 21 is connected with the cathode of an electrochemical machining power supply through a power clamp.
And step two, mounting the processed workpiece 5 on a workbench, and connecting the processed workpiece 5 with the anode of the electrochemical machining power supply.
Step three, electrolyte with the temperature of 70 ℃ is introduced, the deformation mechanism 3 is in a straightening state, and the feeding system 1 performs feeding motion to drive an electrochemical machining tool to enter the internal area of the machined workpiece from a narrow entrance of the machined workpiece 5; then normal temperature electrolyte with the temperature of 25 ℃ is introduced, the deformation mechanism 3 is in a bending state, the tool cathode 4 reaches the initial processing position, and the processing gap is adjusted.
And step four, continuously supplying normal-temperature electrolyte at the temperature of 25 ℃, switching on an electrolytic machining power supply, and driving the electrolytic machining tool to perform feeding motion under the driving of the feeding system 1 to perform electrolytic machining.
And step five, when the blind hole on the inner wall of the variable-section pipeline is machined, disconnecting the electrolytic machining power supply, introducing electrolyte at the temperature of 70 ℃, enabling the deformation mechanism 3 to be in a high-temperature phase straightening state, driving the electrolytic machining tool to exit from the machining area by the feeding system, stopping supplying the electrolyte, and finishing one-step forming machining of the blind hole on the inner wall with poor accessibility.

Claims (5)

1. An electrochemical machining tool for complex inner wall structures with poor accessibility, characterized in that: comprises a cathode mechanism (4), a deformation mechanism (3) and a connecting mechanism (2);
the cathode mechanism (4) comprises a cathode body (43) with a hollow cavity, and electrolyte outlets (42) are uniformly distributed on a working surface (41) of the cathode body (43);
the deformation mechanism (3) comprises a deformation rod (31) and a hose (32) with two sealed ends, the deformation rod (31) is coaxially and fixedly arranged in the sealed hose (32), and the deformation rod (31) is made of shape memory alloy; one end of the hose (32) is communicated with the cathode body (43) through more than two communicating pipes; the other end of the hose (32) is communicated with more than two liquid inlet pipes (37);
in the preparation processing stage, high-temperature electrolyte is introduced into a hose (32) of the deformation mechanism, and the deformation rod (31) is in a high-temperature phase straightening state, so that an electrochemical processing tool enters an inner cavity of a processed workpiece;
in the processing stage, normal-temperature electrolyte is introduced into a hose (32) of the deformation mechanism, the electrolyte is introduced into a cathode body (43) through the hose (32), the deformation rod (31) is in a low-temperature phase bending state, and the cathode body (43) reaches a region to be processed and is processed according to a set processing gap;
and after the processing is finished, introducing high-temperature electrolyte into a hose (32) of the deformation mechanism, and enabling the deformation rod (31) to exit from the processing area in a straightening state.
2. An electrochemical machining tool for a complex inner wall structure with poor accessibility according to claim 1, characterized in that: a plurality of horizontal slit-shaped electrolyte outlets (42) are uniformly distributed on the working surface (41) of the cathode body (43).
3. An electrochemical machining tool for a complex inner wall structure with poor accessibility according to claim 2, characterized in that: the width of the seam of the electrolyte outlet (42) is 1-2 mm, and the length of the seam is 10-12 mm.
4. An electrochemical machining tool for a complex inner wall structure with poor accessibility according to claim 1, characterized in that: the cathode body (43) is a hollow cube, one side surface of the cathode body is a working surface (41), and the shape of the working surface (41) is matched with the shape of a surface to be processed of a processed workpiece; the other opposite side surface is communicated with more than two communicating pipes.
5. An electrochemical machining tool for a complex inner wall structure with poor accessibility according to claim 1, characterized in that: an upper end cover (33) is arranged at one end of the hose (32), and a lower end cover (34) is arranged at the other end of the hose (32), so that the hose (32) forms a hose with two sealed ends; the middle part of the outer side of the lower end cover (34) is fixedly connected with the cathode body (43) through a second connecting rod (22), and the middle part of the outer side of the upper end cover (33) is connected with one end of the first connecting rod (21).
CN201911155381.XA 2019-11-22 2019-11-22 Electrochemical machining tool for complex inner wall structure with poor accessibility Active CN110842307B (en)

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CN112404616A (en) * 2020-11-13 2021-02-26 合肥工业大学 Device and method for processing complex cavity by electric spark forming
CN112453603A (en) * 2020-11-27 2021-03-09 合肥工业大学 Sleeve-shaped electrochemical machining electrode capable of machining various complex hole patterns

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