CN113231703B - Adaptive tool cathode and complex inner channel electrolytic finishing method - Google Patents

Abstract

The invention provides a self-adaptive tool cathode and a complex inner channel electrolytic finishing method, which belongs to the technical field of special processing. The self-adaptive tool cathode is composed of a wear-resistant nylon bag, a positioning steel ball, a positioning screw, an adaptive steel ball, a tightening hoop and a conductive column. The self-adaptive steel ball and the positioning steel ball are sealed in the cloth bag by the tight hoop to form a graded granary-shaped tool cathode with a cylinder at the bottom and a cone at the top. The self-adaptive steel ball can be rolled in the airtight nylon bag to adapt to the change of the inner channel section. The conductive column is consolidated by the conductive flexible shaft and the main shaft of the machine tool, and the flexible cathode is driven by the main shaft to realize the axial reciprocating feeding of the inner channel, and the electrolytic finishing of the complex inner channel is completed. This novel self-adaptive tool has good cathode flexibility, and can adapt to any constant cross-section and various variable cross-section complex inner channels such as circles, rectangles and diamonds, improve the accessibility of electrolytic machining, and realize electrolytic finishing of complex inner channels.

Description

Adaptive tool cathode and complex inner channel electrolytic finishing method

technical field

The invention relates to an adaptive tool cathode and a complex inner channel electrolytic finishing method, belonging to the technical field of special processing.

Background technique

Metal additive manufacturing technology can realize the formation of complex metal components and the intensification of multiple parts, so that the structure of complex structural parts can be completely reshaped based on product performance, the design is more free, and the integrated molding is used in aerospace. Manufacture of key complex and high-performance metal components in the fields of biomedical, hydraulic and mold making. For example, NASA used additive manufacturing technology to process a GRCo-84 copper alloy engine combustion chamber in 2015. There are more than 200 complex channels between the inner and outer walls. These channels are three-dimensional special-shaped twisted structures with variable cross-sections.

At present, metal additive manufacturing technology can not only realize circular, rectangular, and diamond-shaped inner channels with constant cross-section, but also realize the forming and manufacturing of variable-section inner channels whose cross-sectional shape changes with the axial direction of the inner channel. The axis of the inner channel can also be a curved trajectory. However, due to the adhesion of a large amount of incompletely melted powder, slag particles and spheroidization effect on the surface of these complex additive manufacturing inner channel parts, and poor fusion and steps between layers, the surface roughness of metal parts is high, which often cannot be Meet the design requirements of components. Therefore, the complex inner channel of the metal additive manufacturing component needs to be subjected to a finishing process to maximize its due performance. At this stage, the main finishing technologies include mechanical polishing, magnetic polishing, abrasive flow and laser finishing, etc. These technologies can basically meet the requirements for simple channels, but there are still existing technologies for variable-section channels, thin-walled component channels, and complex curved channels. If it is not enough, it is prone to the phenomenon of uneven removal and damage to the inner channel wall.

Electrolytic finishing has the characteristics of high processing efficiency, no loss of tool electrodes, no stress during processing, and good surface integrity, and electrolytic machining is a non-contact processing that is not limited by the shape and movement of the tool cathode. Therefore, innovatively designing the tool cathode form and movement mode to improve the accessibility and flexibility of the tool cathode can realize the finishing of complex internal channels of metal additive manufacturing components.

SUMMARY OF THE INVENTION

In order to improve the surface quality of the inner channel of the metal additive manufacturing component, the present invention proposes an adaptive tool cathode and an electrolytic finishing method for a complex inner channel. , rectangle and rhombus, any constant cross-section and various variable cross-section complex inner channels, improve the accessibility of electrolytic machining, and realize electrolytic finishing of complex inner channels.

An adaptive tool cathode, comprising a wear-resistant nylon cloth bag, a positioning steel ball, an adaptive steel ball, a clamp and a conductive column;

The positioning steel balls are placed in the middle of the bottom of the nylon bag, and the self-adaptive steel balls are tightly packed around the positioning steel balls;

The above-mentioned tightening hoop seals the wear-resistant nylon bag along the circumference of the conductive column, and at the same time fastens the positioning steel ball and the self-adaptive steel ball to form a graded granary-shaped tool cathode with a cylinder at the bottom and a cone at the top.

Utilize the above-mentioned adaptive tool cathodic electrolytic finishing to process the complex inner channel method, including the following process:

1) The complex inner channel workpiece is installed and fixed on the machine table through the fixture, and the adaptive tool cathode is placed in the inner channel workpiece, and is accurately positioned and installed to the to-be-processed area of the workpiece;

2) The self-adaptive steel ball can be rolled in the wear-resistant nylon cloth bag, and the position of the clamp can be adjusted up and down along the axis of the conductive column, and the tool cathode with the same cross-sectional shape as the inner channel can be formed adaptively;

3) Connect the adaptive tool cathode with the first machine tool spindle through the first conductive flexible shaft above, and connect it with the second machine tool spindle through the lower second conductive flexible shaft, and adjust the first machine tool spindle and the second machine tool spindle with the inner Channel the workpiece position, so that there is a certain pre-tensioning force on the first conductive flexible shaft and the second conductive flexible shaft;

4) Connect the negative electrode of the adaptive tool to the negative electrode of the power supply, and connect the workpiece of the inner channel to be connected to the positive electrode of the power supply;

5) Turn on the electrolyte supply system, turn on the power supply, the first machine tool spindle and the second machine tool spindle drive the self-adaptive tool cathode to reciprocate through the first conductive flexible shaft and the second conductive flexible shaft, so as to realize the electrolytic light of the complex inner channel. finishing;

6) After a period of processing, when the surface roughness of the inner channel workpiece reaches the processing requirements, stop processing.

The diameter of the above-mentioned positioning steel ball is half of the minimum cross-sectional dimension of the inner channel of the inner channel workpiece.

The positioning steel ball is placed in the middle of the bottom of the nylon cloth bag, and is fixed to the nylon cloth bag by insulating glue and plastic positioning screws.

The above-mentioned self-adaptive steel balls are stainless steel equal-diameter balls with two or more diameter specifications. The lower equal-diameter balls are closely packed around the positioning steel ball at the bottom of the cloth bag, and under the constraint of the cloth bag, they are closely attached to the outer surface of the positioning steel ball, and are stacked into a cylinder, and the height of the cylinder is generally 3-5mm. The upper self-adaptive steel ball, the positioning steel ball and the conductive column are in close contact, and the number gradually decreases with the increase of the height, forming a cone with a large lower volume and a small upper volume.

The position of the above-mentioned tightening hoop can be adjusted up and down along the axial direction of the conductive column, and the volume of the tool cathode can be changed by adjusting the position of the tightening hoop, so as to adapt to the change of the cross section along the axial direction.

The above-mentioned self-locking nylon rolling belt with stopper and retraction has the characteristics of softness, good toughness, fast tightening, good insulation and self-locking tightening.

The lower end of the above-mentioned conductive column is fixed by threads and positioning steel balls, and several radial grooves are arranged in the middle position, which is convenient for sealing and adjusting the position of the tightening hoop.

Description of drawings

Figure 1 Schematic diagram of adaptive tool cathode

Figure 2 is a schematic diagram of the inner channel of the self-adaptive tool cathode electrolytic finishing

Figure 3 shows the cross-section of various inner channels processed by the adaptive tool cathode

Figure 4 shows the complex curved inner channel of the adaptive tool cathode

The label names in the figure are: 1. Wear-resistant nylon bag; 2. Positioning steel ball; 3. Positioning screw; 4. Self-adaptive steel ball; The first machine tool spindle; 9, the power supply; 10, the inner channel workpiece; 11, the fixture; 12, the machine tool table; 13, the second conductive flexible shaft; 14, the second machine tool spindle.

Detailed ways

The present invention will be further described in detail below with reference to the specific drawings.

As shown in FIG. 1 , the adaptive tool cathode proposed by the present invention includes a wear-resistant nylon cloth bag 1 , a positioning steel ball 2 , a positioning screw 3 , an adaptive steel ball 4 , a tightening hoop 5 , and a conductive column 6 . Place the positioning steel ball 2 in the middle of the bottom of the nylon bag 1, and fix it with insulating glue and plastic positioning screws 3 and the nylon cloth bag; the lower adaptive steel ball 4 is tightly packed around the positioning steel ball at the bottom of the cloth bag, under the constraints of the cloth bag and The outer surface of the positioning steel balls is close to each other and stacked into a cylinder, the height of the cylinder is generally 3-5mm; the number of the upper adaptive steel balls gradually decreases with the increase of the height, forming a cone with a large lower volume and a small upper volume; The lower end of the conductive column 6 is fixed by the thread and the positioning steel ball 2 , and finally the nylon cloth bag 1 is sealed along the circumference of the conductive column 6 with a non-return self-locking clamp 5 .

As shown in FIG. 2 , the method of self-adaptive tool cathode electrolytic finishing proposed by the present invention for processing channels in complex cross-sections is characterized by comprising the following steps:

1) The complex inner channel workpiece 10 is installed and fixed on the machine tool table 12 through the fixture 11, and the tool cathode is placed in the inner channel workpiece 10, and is accurately positioned and installed to the to-be-processed area of the workpiece;

2) Adjust the position of the clamp 5 so that the volume of the tool cathode matches the cross section of the inner channel 10;

3) Connect the tool cathode to the machine tool spindles 8 and 14 through the conductive flexible shafts 7 and 13 respectively, and adjust the positions of the machine tool spindles 8 and 14 and the inner channel workpiece 10 so that the two conductive flexible shafts 7 and 13 have a certain pretension. tightness;

4) Connect the negative pole of the tool to the negative pole of the power supply 9, and connect the inner channel workpiece 10 to be processed to the positive pole of the power supply 9;

5) Turn on the electrolyte supply system, turn on the power supply 9, the machine tool spindles 8 and 14 drive the tool cathode to reciprocate through the conductive flexible shafts 7 and 13, and realize the electrolytic finishing of the complex inner channel;

6) After a period of processing, when the surface roughness of the inner channel workpiece 9 meets the processing requirements, stop processing.

As shown in Figure 3, the tiny steel balls in the self-adaptive tool cathode proposed by the present invention can roll freely in the flexible wear-resistant nylon cloth bag, and adapt to the channels in various shapes of cross-sections. The inner channel finishing process in the cross-section can also realize the curved inner channel finishing process as shown in FIG. 4 .

Claims (9)

1. An adaptive tool cathode, characterized in that: Including wear-resistant nylon cloth bag (1), positioning steel ball (2), self-adaptive steel ball (4), tightening hoop (5) and conductive column (6); The above-mentioned positioning steel balls (2) are placed in the middle of the bottom of the nylon cloth bag (1), and the self-adaptive steel balls (4) are tightly packed around the positioning steel balls (2); ) upper consolidation; The above-mentioned tightening hoop (5) seals the wear-resistant nylon cloth bag (1) along the circumference of the conductive column (6), and at the same time tightly seals the positioning steel ball (2) and the self-adaptive steel ball (4) to form a cylinder with a lower part and an upper part. It is a cone-shaped grading silo-shaped tool cathode. 2. The adaptive tool cathode according to claim 1, characterized in that: The diameter of the positioning steel ball (2) is half of the minimum cross-sectional dimension of the inner channel of the inner channel workpiece (10). 3. The adaptive tool cathode according to claim 1, characterized in that: The above positioning steel ball (2) is fixed by insulating glue, plastic positioning screw (3) and the bottom of the nylon cloth bag (1). 4. The adaptive tool cathode according to claim 1, characterized in that: The above-mentioned self-adaptive steel balls (4) are stainless steel equal-diameter balls with two or more diameter specifications. 5. The adaptive tool cathode according to claim 1, characterized in that: The height of the cylinder formed by the self-adaptive steel ball (4) is generally 3-5mm. 6. The adaptive tool cathode according to claim 1, characterized in that: The position of the above-mentioned tightening hoop (5) can be adjusted up and down along the axial direction of the conductive column (6). By adjusting the position of the tightening hoop (5), the volume of the cathode of the tool can be changed to adapt to the axial change of the cross section. 7. The adaptive tool cathode according to claim 1, wherein: The above-mentioned tightening hoop (5) stops the self-locking nylon rolling belt. 8. The adaptive tool cathode according to claim 1, wherein: The lower end of the above-mentioned conductive column (6) is fixed by the thread and the positioning steel ball (2), and several radial grooves are set in the middle position, which is convenient for sealing and adjusting the position of the tightening hoop. 9. utilize the self-adaptive tool cathode electrolytic finishing method complex inner channel method according to claim 1, it is characterized in that comprising the following process: 1) The complex inner channel workpiece (10) is installed and fixed on the machine tool table (12) through the fixture (11), the adaptive tool cathode is placed in the inner channel workpiece (10), and is accurately positioned and installed to the workpiece to be processed area ; 2) The self-adaptive steel ball (4) can be rolled in the wear-resistant nylon cloth bag (1), and the position of the clamping hoop (5) can be adjusted up and down along the axis of the conductive column to form a tool cathode with the same cross-sectional shape as the inner channel; 3) Connect the adaptive tool cathode to the first machine tool spindle (8) through the first conductive flexible shaft (7) above, and connect it to the second machine tool spindle (14) through the second conductive flexible shaft (13) below, And adjust the position of the first machine tool spindle (8) and the second machine tool spindle (14) and the inner channel workpiece (10), so that there is a certain pretension on the first conductive flexible shaft (7) and the second conductive flexible shaft (13). tightness; 4) Connect the negative electrode of the adaptive tool to the negative electrode of the power supply (9), and the workpiece (10) of the inner channel to be processed is connected to the positive electrode of the power supply (9); 5) Turn on the electrolyte supply system, turn on the power supply (9), the first machine tool spindle (8) and the second machine tool spindle (14) pass through the first conductive flexible shaft (7) and the second conductive flexible shaft (13) ) to drive the reciprocating motion of the self-adaptive tool cathode to realize electrolytic finishing of complex inner channels; 6) After a period of processing, when the surface roughness of the inner channel workpiece (10) meets the processing requirements, stop processing.

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