Monitoring device and method for the gap in trepanning electrochemical machining and the blade forming process

Abstract

The invention discloses a monitoring device and method for the gap in trepanning electrochemical machining and the blade forming process, belonging to the field of electrochemical machining. The device includes: a sealed fixture, a cathode module, a light source module, and an observation recorder. A transparent observation window is arranged on the sealed fixture, and the changes of products such as the electrolyte flow channel and bubbles in the tiny gap are observed through the observation recorder, and the forming state of the blade inside the insulating water jacket at different machining moments is photographed. Lightsources in different regions are designed to provide multi-sided lighting for the gap in trepanning electrochemical machining, and parallel laser beams accurately supply multiple points to the tiny machining gap and the flow channel region around the water jacket. The laser focus is adjusted to be located in the bubble aggregation region, and the focused laser will break through the bubbles to realize the on-line control of the electrochemical machining process. An open-type thin-sheet cathode and an open-type transparent insulating water jacket are designed to be close to the rib on one side of the observation window; the electrolyte flow field characteristics in the actual machining process are not changed.

Description

Technical Field

[0001] The design of the present invention belongs to the field of electrochemical machining, and specifically relates to a device and method for monitoring the gap in trepanning electrochemical machining and the forming process of blades. Background Art

[0002] Trepanning electrochemical machining belongs to a special machining process. A part contour is machined inside the cathode according to the shape of the workpiece contour. A reserved channel with a cross-section of the part contour is machined inside the insulating water jacket and waits for the machined blade to enter. The workpiece is connected to the positive electrode of the power supply, and the tool cathode is connected to the negative electrode of the power supply. During the machining process, the tool cathode feeds towards the workpiece, and the workpiece material facing the machining surface of the cathode is electrolytically etched away. The high-speed flowing electrolyte carries away the electrolysis products. After the workpiece reaches the specified distance, the final forming is completed. The characteristics of trepanning electrochemical machining are that the full contour is machined and formed at one time, and the machining efficiency and machining accuracy are relatively high. It is widely used in the fields of aviation, aerospace, etc.

[0003] The invention patent with the patent number CN109693010B cuts the actual machining process from the middle section and observes the fluid flow, bubble generation, and product discharge during the small-hole electrochemical machining through a transparent glass, which changes the electrolyte flow field characteristics in the actual machining process.

[0004] In the article "Research on the Current Characteristics of Pulse Dynamic Electrochemical Machining Based on High-Speed Photography", the back-projected light source is used to observe the machining products, which will cause the light intensity in the machining gap to be too high.

[0005] In the article "Real-time vision-assisted electrochemical machining with constant inter-electrode gap", for the evolution of the inter-electrode gap during the electrochemical machining process, visual assistance is used as a passive on-line inter-electrode gap measurement and control technology, and the changes in the products and the generation of bubbles in the machining gap cannot be observed.

[0006] The observation methods and devices in the above-mentioned articles and patents cannot observe the changes in the products and the generation of bubbles in the gap; the currently publicly reported literature cannot observe the forming process and product changes in trepanning electrochemical machining. Therefore, a new observation device is needed that does not change the electrolyte flow field characteristics during actual machining, ensures uniform light intensity in the machining gap, and can monitor the changes in the products and the forming process in the micro-gap. Summary of the Invention

[0007] The purpose of the present invention is to provide a device and method that are convenient for clearly monitoring the flow of the electrolyte in the machining gap of the trepanning electrochemical machining blade, the generation of bubbles, and the forming of the blade, so as to optimize the flow field and improve the machining method according to the characteristics of the electrolyte flow field.

[0008] A monitoring device for the machining gap and blade forming process in trepanning electro-chemical machining, the main features of which include a sealed fixture, a cathode module, a light source module, and an observation recorder;

[0009] The sealed fixture includes a fixture body, an upper side flow guide block, a conductive block, and a lower side flow guide block; a machining cavity is provided inside the fixture body; the upper side flow guide block, the conductive block, and the lower side flow guide block are arranged on the right wall surface of the fixture body in sequence from top to bottom; the workpiece is located inside the machining cavity and is fixed jointly by the fixture body and the conductive block; an observation window is provided on the front wall surface of the fixture body, and a back light source window and a back light source channel are opened on the back wall surface of the fixture body; the back light source window uses a transparent material, and the observation window is made of transparent organic glass;

[0010] The cathode module includes three parts: a thin sheet cathode, an insulating water jacket, and a cathode base; the insulating water jacket is fixed on the cathode base, and a machining blade entry deep groove is provided in the middle of the insulating water jacket, and diversion shallow grooves are connected to both sides of the entry deep groove; the diversion shallow grooves are connected to the electrolyte channels of the cathode base through the electrolyte channels of the insulating water jacket; the thin sheet cathode is installed on the upper surface of the diversion shallow groove of the insulating water jacket and is fixed to the cathode base; a liquid outlet is provided at the center of the machining end surface of the thin sheet cathode, i.e., at a position corresponding to the entry deep groove; the liquid outlet of the thin sheet cathode and the entry deep groove of the insulating water jacket are both of notch type structures, that is, the relevant groove structures have no front wall surface and are directly attached to the transparent observation window;

[0011] The light source module includes a front laser light source, a back light source, and a side light source; the front laser light source and the observation recorder are installed together directly in front of the observation window; the back light source is installed at a position corresponding to the back light source window; the above-mentioned insulating water jacket is made of a transparent material, and a side light source channel is provided inside the cathode base, and this side light source channel extends to the transparent insulating water jacket, and the above-mentioned side light source is installed in this side light source channel.

[0012] The method for monitoring the machining gap and blade forming process of the trepanning electro-chemical machining blade is characterized by including the following processes:

[0013] The electrolyte flows out from the diversion shallow grooves after passing through the electrolyte channels of the cathode base and the electrolyte channels of the insulating water jacket, flows into the entry deep groove, fills the entry deep groove and then flows out from the liquid outlet of the thin sheet cathode; after flowing through both sides of the workpiece, it flows out from the outlets of the upper side flow guide block and the lower side flow guide block respectively;

[0014] After flowing into the inlet of the insulating water jacket, it enters the machined blade channel reserved in the insulating water jacket along the circular channel, and flows into the machining gap from the liquid outlet channel of the thin sheet cathode; after the electrolyte passes through the machining gap between the thin sheet cathode and the workpiece, it flows out from the upper and lower liquid outlet channels between the side wall of the thin sheet cathode and the upper side flow guide block and the lower side flow guide block;

[0015] A front laser light source, a back light source and a side light source are used to provide multi-sided light to the trepanning electrochemical machining gap, and parallel laser beams supply precisely to the tiny machining gap and the flow channel area around the water jacket at multiple points;

[0016] Adjust the laser focal length of the front laser light source so that the laser focus is located in the bubble aggregation area, and the focused laser will break through the bubbles.

[0017] The advantages of the present invention are as follows:

[0018] (1) Design a sealed observation fixture. A transparent observation window is arranged on the sealed fixture. The changes of products such as the electrolyte flow channel and bubbles in the tiny gap and the forming state of the blades inside the insulating water jacket at different machining moments are observed through an observation recorder, realizing the on-line monitoring of the blade forming process and providing support for the research on the mechanism of the trepanning electrochemical machining process.

[0019] (2) Design light sources for different regions, including a front laser light source, a back light source and a side light source, to provide multi-sided light to the trepanning electrochemical machining gap, and parallel laser beams supply precisely to the tiny machining gap and the flow channel area around the water jacket at multiple points, solving the problems of insufficient light or uneven light intensity in the tiny machining gap and improving the observation accuracy.

[0020] (3) The liquid outlet of the thin sheet cathode and the deep groove for the entry of the insulating water jacket are both of notch structures. The notch sides are closely attached to the transparent observation window, without changing the electrolyte flow field characteristics in the actual machining process, realizing the on-line observation of the real electrochemical machining process.

[0021] (4) Adjust the laser focal length of the front laser light source so that the laser focus is located in the bubble aggregation area. The focused laser will break through the bubbles, improving the machining stability; accelerating the discharge of products and reducing the conductivity change at the liquid inlet and outlet, improving the machining accuracy and realizing the on-line control of the electrochemical machining process. Description of the Drawings

[0022] Figure 1 It is a schematic diagram of the overall front assembly

[0023] Figure 2 It is a schematic diagram of the overall back assembly

[0024] Figure 3 It is a schematic diagram of the position of the observation window

[0025] Figure 4 It is a schematic diagram of the structure of the thin sheet cathode

[0026] Figure 5 It is a schematic diagram of the structure of the insulating water jacket

[0027] Wherein: 1-fixture main body, 2-cathode seat, 3-thin sheet cathode, 4-insulating water jacket, 5-side

[0028] Light source, 6 - Workpiece, 7 - Front illumination light source, 8 - Observation and recording instrument, 9 - Upper side diversion block, 10 - Conductive block, 11 - Lower side diversion block, 12 - Back light source window, 13 - Back light source, 14 - Observation window. Specific implementation method

[0029] The working method of the present invention will be further elaborated below in combination with the operation steps of workpiece processing:

[0030] (1) Assemble the cathode module and the sealed fixture;

[0031] (2) Install the light source module and the observation and recording instrument;

[0032] (3) Connect the electrolyte pipe and the cathode and anode wires;

[0033] (4) Start the electrolyte circulation system;

[0034] (5) Clamp the workpiece and adjust it to the initial processing position;

[0035] (6) Start the light source module and the observation and recording instrument;

[0036] (7) Start the processing power supply, the cathode feeds horizontally to the right, and start processing;

[0037] (8) Conduct on - line monitoring of the processing gap and the inside of the insulating water jacket;

[0038] (9) After processing, stop the power supply and the electrolyte circulation system, turn off the light source module and the observation and recording instrument, the cathode returns to the initial position, and remove the processed workpiece;

[0039] (10) After processing, turn off the power supply system and the electrolyte circulation system.

Claims

1. A monitoring device for the gap in trepanning electrochemical machining and the blade forming process, characterized in that: It includes a sealed fixture, a cathode module, a light source module, and an observation recorder; The sealed fixture includes a fixture body (1), an upper side flow guide block (9), a conductive block (10), and a lower side flow guide block (11); there is a processing cavity inside the fixture body (1); the upper side flow guide block (9), the conductive block (10), and the lower side flow guide block (11) are arranged on the right wall surface of the fixture body (1) from top to bottom in sequence; the workpiece (6) is located in the processing cavity and is fixed jointly by the fixture body (1) and the conductive block (10); an observation window (14) is provided on the front wall surface of the fixture body (1), and a back light source window (12) and a back light source channel are opened on the back wall surface of the fixture body (1); the back light source window (12) uses a transparent material, and the observation window (14) is made of transparent organic glass; The cathode module includes three parts: a thin cathode (3), an insulating water jacket (4), and a cathode base (2); the insulating water jacket (4) is fixed on the cathode base (2), and a processed blade inlet deep groove is provided in the middle of the insulating water jacket (4), and diversion shallow grooves are connected to both sides of the inlet deep groove; the diversion shallow grooves are communicated with the electrolyte channels of the cathode base (2) through the electrolyte channels of the insulating water jacket (4); the thin cathode (3) is installed on the upper surface of the diversion shallow groove of the insulating water jacket (4) and is fixed to the cathode base (2); a liquid outlet is provided at the center of the processing end face of the thin cathode (3), that is, at a position corresponding to the inlet deep groove; the liquid outlet of the thin cathode (3) and the inlet deep groove of the insulating water jacket (4) are both notch-type structures, that is, the relevant groove structures have no front wall surface and are directly attached to the transparent observation window (14); The light source module includes a front laser light source (7), a back light source (13), and a side light source (5); the front laser light source (7) and the observation recorder (8) are installed together directly in front of the observation window (14); the back light source (13) is installed at a position corresponding to the back light source window (12); the above-mentioned insulating water jacket (4) is made of a transparent material, and a side light source channel is provided inside the cathode base (2), and the side light source channel extends to the transparent insulating water jacket (4), and the above-mentioned side light source (5) is installed in the side light source channel.

2. The method for monitoring the machining gap and blade forming process of the trepanning electrochemical machining according to claim 1, wherein It includes the following processes; The electrolyte flows out from the diversion shallow groove after passing through the electrolyte channels of the cathode base (2) and the electrolyte channels of the insulating water jacket (4), flows into the inlet deep groove, fills the inlet deep groove and then flows out from the liquid outlet of the thin cathode (3); after flowing through both sides of the workpiece (6), it flows out from the outlets of the upper side flow guide block (9) and the lower side flow guide block (11) respectively; After flowing into the liquid inlet of the insulating water jacket (4), it enters the processed blade channel reserved in the insulating water jacket (4) along the circular channel and flows into the processing gap from the liquid outlet channel of the thin cathode (3); after the electrolyte passes through the processing gap between the thin cathode (3) and the workpiece (6), it flows out from the upper and lower liquid outlet channels between the side wall of the thin cathode (3) and the upper side flow guide block (9) and the lower side flow guide block (11); The front laser light source (7), the back light source (13), and the side light source (5) perform multi-side light supply to the trepanning electrochemical machining gap, and the parallel laser beams supply accurately to the tiny processing gap and the flow channel area around the water jacket at multiple points; Adjust the laser focal length so that the laser focus is located in the bubble aggregation area. The focused laser will break through the bubbles, accelerate the discharge of products and increase the conductivity, realizing the on-line control of the electrochemical machining process.

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