Bubble space-time control and observation system during EDM process

Abstract

The present invention discloses a bubble spatiotemporal control and observation system during electrospark machining, including a power supply, a discharge platform and a high-speed camera, wherein the power supply is a programmable pulse discharge power supply, and the positive and negative electrodes of the power supply are respectively connected to a first electrode and a second electrode; a height adjustment component and a transparent resin block are arranged on the discharge platform; the spacing between the first electrode and the second electrode is adjusted by the height adjustment component, and the second electrode is embedded in the transparent resin block, and the second electrode is an electrode wire; a groove is provided on the top of the transparent resin block, and a working fluid is contained in the groove, and the working fluid is arranged between the first electrode and the second electrode; a high-speed camera is used to shoot bubbles generated in the working fluid, and the shooting speed of the high-speed camera is 20,000 frames per second to 30,000 frames per second. The present invention solves the problem that it is difficult to observe the morphological changes and movement of bubbles in previous studies on electrospark machining, and realizes the spatiotemporal control of bubbles in the electrospark discharge gap.

Description

Technical Field

[0001] The invention relates to the technical field of bubble control and observation in electrospark machining, and in particular to a bubble time-space control and observation system in the electrospark machining process. Background Art

[0002] In the field of EDM, the formation and evolution of bubbles is a key factor affecting machining stability and efficiency. Unlike bubble research in other fields, bubbles in EDM are unique in terms of scale, distribution, and spatial size. Their formation and evolution are affected by multiple physical fields, and it is difficult to determine the shape of bubbles in the machining gap (usually irregular) and the movement of bubbles. At present, the study of the formation and evolution of bubbles in EDM is very difficult. The change process of bubbles in EDM is extremely short, usually only a few hundred microseconds, and the inter-electrode gap is blocked by the electrode and the workpiece, making it difficult to observe the movement of bubbles in the gap. Moreover, the light emitted by the EDM discharge is brighter, and its luminous area covers the bubbles in the early stage of the discharge, making it difficult to distinguish the outline of the bubbles. In addition, since the bubbles generated in the EDM process are random in time and space, it is even more difficult to observe the bubbles in the discharge gap. Summary of the invention

[0003] The purpose of the present invention is to provide a bubble time and space control and observation system during electrospark machining, which can realize the observation of bubbles in the discharge gap and the bubble time and position control during multi-pulse discharge, and solve the problems existing in the above-mentioned prior art.

[0004] To achieve the above object, the present invention provides the following solution: The present invention provides a bubble time-space control and observation system during electrospark machining, comprising:

[0005] A power supply, wherein the power supply is a programmable pulse discharge power supply, and the positive and negative electrodes of the power supply are respectively connected to the first electrode and the second electrode;

[0006] A discharge platform, wherein a height adjustment component and a transparent resin block are arranged on the discharge platform; the distance between the first electrode and the second electrode is adjusted by the height adjustment component, the second electrode is embedded in the transparent resin block, and the second electrode is an electrode wire; a groove is provided on the top of the transparent resin block, and a working fluid is contained in the groove, and the working fluid is arranged between the first electrode and the second electrode;

[0007] A high-speed camera is used to photograph the bubbles generated in the working fluid, and the shooting speed of the high-speed camera is 20,000 frames per second to 30,000 frames per second.

[0008] Preferably, it also includes a filter, which is placed at the lens of the high-speed camera and allows only light of one wavelength to pass through.

[0009] Preferably, it further comprises a laser, wherein the laser is used to irradiate bubbles generated in the working fluid, the light emitted by the laser is monochromatic light, and the light emitted by the laser can pass through the filter.

[0010] Preferably, the height adjustment assembly includes a cylindrical rod fixedly mounted on one end of the top of the discharge platform, the cylindrical rod being arranged perpendicular to the discharge platform; a cross bar is slidably sleeved on the cylindrical rod, both ends of the cross bar are installed with flower-shaped knobs, the first electrode is detachably mounted on the cross bar via the flower-shaped knob, the first electrode is arranged corresponding to the second electrode in the transparent resin block, the cross bar is fixedly matched with the cylindrical rod via the flower-shaped knob, and the cross bar is arranged parallel to the discharge platform.

[0011] Preferably, the discharge platform is a marble platform.

[0012] Preferably, a circular hole is opened in the middle of the discharge platform, an annular fill light is fixedly installed in the circular hole, and the transparent resin block is arranged corresponding to the circular hole.

[0013] Preferably, a support frame is installed at the bottom end of the discharge platform, an L-shaped bracket is installed on the inner side of the support frame, the high-speed camera is installed on the L-shaped bracket, and the lens of the high-speed camera is arranged corresponding to the circular hole.

[0014] Preferably, the first electrode is a screw micrometer head, and the screw micrometer head is used to control the gap size between the first electrode and the second electrode.

[0015] Preferably, a support plate is provided on the discharge platform, and the support plate is an acrylic plate. The support plate is arranged corresponding to the circular hole, and the transparent resin block is placed on the support plate.

[0016] The present invention discloses the following technical effects:

[0017] The spatiotemporal control and observation system of the electric spark discharge bubble established by the technical solution of the present invention is a key measure to study the formation and evolution (expansion-contraction, fragmentation, growth, fusion) mechanism of single pulse discharge bubbles and multi-pulse discharge bubbles. It solves the problem that it is difficult to observe the morphological changes and movement of bubbles in previous studies of electric spark machining bubbles, and realizes the spatiotemporal control of bubbles in the electric spark discharge gap. It is a technical breakthrough in the study of bubbles in the field of electric spark machining, and can lead the research direction in the field of electric spark machining, such as intelligent control of the formation and evolution process of bubbles to improve the stability and efficiency of electric spark machining. The research method and research results of the present invention can provide new ideas and methods for bubble research in other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a structural schematic diagram of the bubble time-space control and observation system during the electrospark machining process of the present invention;

[0020] Figure 2 This is a schematic diagram of the principle of the single pulse discharge bubble expansion-contraction observation system;

[0021] Figure 3 Schematic diagram of the spatiotemporal control and observation system for the formation and evolution of multi-pulse discharge bubbles;

[0022] Among them, there are discharge platform-1, transparent resin block-2, working fluid-3, high-speed camera-4, filter-5, laser-6, cylindrical rod-7, cross bar-8, flower-shaped knob-9, ring fill light-10, support frame-11, screw micrometer-12, support plate-13, electrode wire-14. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] The present invention provides a bubble time-space control and observation system during electrospark machining, comprising:

[0026] A power supply, which is a programmable pulse discharge power supply, wherein the positive and negative electrodes of the power supply are respectively connected to the first electrode and the second electrode;

[0027] A discharge platform 1 is provided with a height adjustment component and a transparent resin block 2; the distance between the first electrode and the second electrode is adjusted by the height adjustment component, the second electrode is embedded in the transparent resin block 2, and the second electrode is an electrode wire 14; a groove is provided on the top of the transparent resin block 2, and a working fluid 3 is contained in the groove, and the working fluid 3 is provided between the first electrode and the second electrode;

[0028] High-speed camera 4 is used to shoot the bubbles generated in the working fluid 3. The time for the electric spark discharge to generate bubbles is very short, and the time experienced by the formation of bubbles is about 300 microseconds. Therefore, the high-speed camera 4 used can shoot at a shooting speed of 20,000 frames per second to 30,000 frames per second.

[0029] Furthermore, it also includes a filter 5, which is placed at the lens of the high-speed camera 4 and allows only one wavelength of light to pass through. The light emitted by the spark discharge is brighter, and its luminous area covers the bubbles in the early stage of the discharge, making it difficult to distinguish the outline of the bubbles. The present invention places the filter 5 between the high-speed camera 4 and the observed object, and it only allows one wavelength of light to pass through, thus filtering out most of the light from the spark discharge and avoiding light pollution.

[0030] Furthermore, a laser 6 is included, and the laser 6 is used to irradiate the bubbles generated in the working fluid 3. The light emitted by the laser 6 is monochromatic light, and the light emitted by the laser 6 can pass through the filter 5. Although the use of the filter 5 can solve the problem of light pollution, it also brings the problem of insufficient light and dark pictures. Therefore, a monochromatic laser 6 is used to irradiate the observed object, and the light emitted by the laser 6 can pass through the filter 5 to play a role of fill light, so that the outline of the bubble can be clearly photographed.

[0031] Furthermore, the height adjustment component includes a cylindrical rod 7 fixedly mounted on one end of the top of the discharge platform 1, and the cylindrical rod 7 is vertically arranged to the discharge platform 1; a cross bar 8 is slidably sleeved on the cylindrical rod 7, and flower-shaped knobs 9 are installed at both ends of the cross bar 8. The first electrode is detachably mounted on the cross bar 8 through the flower-shaped knob 9, and the first electrode is arranged corresponding to the second electrode in the transparent resin block 2. The cross bar 8 is fixedly matched with the cylindrical rod 7 through the flower-shaped knob 9, and the cross bar 8 is arranged parallel to the discharge platform 1, and the discharge platform 1 is a marble platform.

[0032] Furthermore, a circular hole is provided in the middle of the discharge platform 1, and a ring-shaped fill light 10 is fixedly installed in the circular hole, and the transparent resin block 2 is arranged corresponding to the circular hole. The arrangement of the circular hole can facilitate the installation of a ring-shaped LED white light for fill light, and can also observe the state of the gap between the two electrodes from bottom to top through the circular hole.

[0033] Furthermore, a support frame 11 is installed at the bottom end of the discharge platform 1, an L-shaped bracket is installed inside the support frame 11, a high-speed camera 4 is installed on the L-shaped bracket, and a lens of the high-speed camera 4 is arranged corresponding to the circular hole.

[0034] Furthermore, the first electrode is a screw micrometer head 12, and the screw micrometer head 12 is used to control the gap size between the first electrode and the second electrode.

[0035] Furthermore, a support plate 13 is provided on the discharge platform 1 . The support plate 13 is an acrylic plate. The support plate 13 is provided corresponding to the circular hole. The transparent resin block 2 is placed on the support plate 13 .

[0036] When the present invention is used for experiments, a thin copper wire is embedded in a transparent resin block 2 as a transparent electrode, a spiral micrometer head 12 made of bearing steel is used as a metal electrode, a marble platform is used as a discharge platform 1, the spiral micrometer head 12 is clamped on a crossbar 8, and a transparent resin block 2 embedded with an electrode wire 14 is placed on the marble platform below the spiral micrometer head 12. An acrylic plate with good flatness is used as a support, and the flower-shaped knob 9 close to the cylindrical rod 7 is adjusted to move the crossbar 8 downward, so that the distance between the probe on the spiral micrometer head 12 and the resin block is kept within the range of the spiral micrometer head 12, and then the gap size between the first electrode and the second electrode is controlled by adjusting the spiral micrometer head 12. A programmable pulse discharge power supply is used to control the output pulse number and pulse time interval, so that the subsequent pulse discharge starts after the previous pulse discharge forms bubbles and reaches a steady state. When there is only one electrode wire 14 in the transparent resin block 2, the position of the bubble generated by the discharge is controlled at the position of the electrode wire 14; when the electrode wire 14 in the transparent resin block 2 is changed to two or more, the position of the discharge bubble is controlled by controlling the distance between the electrode wires 14.

[0037] Use a multimeter to connect the two ends of the discharge electrode and adjust it to the ohm range. When the two electrodes are in contact, the multimeter displays the resistance value. When the two electrodes are disconnected, the multimeter displays 0. The specific steps for adjusting the gap size between the first electrode and the second electrode are as follows:

[0038] 1. Make the micrometer screw 12 fit the surface of the transparent resin block 2, and keep the micrometer screw 12 in contact with the copper wire;

[0039] 2. Connect wires at both ends of the electrodes, connect the wires to the multimeter probes respectively, and adjust the multimeter to the ohm range. The resistance value displayed on the multimeter is the resistance value of the wire and the two-pole circuit.

[0040] 3. Rotate the micrometer screw 12 to keep the micrometer screw 12 away from the copper wire on the surface of the transparent resin block 2;

[0041] 4. When the multimeter display jumps back and forth between resistance value and no resistance value, it means that the two poles are about to be disconnected;

[0042] 5. Slowly adjust the micrometer screw 12 to control the distance the micrometer screw 12 moves upward. The distance at this time is the size of the discharge gap.

[0043] In order to realize the observation of the expansion-contraction process of a single pulse discharge bubble, the present invention uses a transparent material as one electrode and a metal material as the other electrode when constructing an observation experimental platform, so as to be able to observe the phenomenon in the gap. During electric spark discharge, the discharge gap is micrometer-level, so it is necessary to fine-tune the gap size between the two electrodes, and the two poles have high requirements for parallelism, so the constructed observation experimental platform requires that the gap size of the two poles can be adjusted, and the two poles have good parallelism.

[0044] In order to realize the observation of the formation and evolution process of multi-pulse discharge bubbles, it is necessary to be able to adjust different discharge parameters. Therefore, the observation experiment of multi-pulse discharge bubbles needs to select a programmable pulse discharge power supply that can output different parameters. The filter is also combined with the laser 6, and the programmable pulse discharge power supply is used to control the number of output pulses and the pulse time interval, so that the subsequent pulse discharge can be started after the previous pulse discharge forms bubbles and reaches a steady state. The position control of the bubbles generated by the discharge is achieved by changing the number of electrode wires 14 in the transparent resin and controlling the discharge position by controlling the distance between the electrode wires 14, thereby realizing the position control of the bubbles. The formation and evolution process of multi-pulse discharge bubbles under the action of multiple fields is observed using a high-speed camera 4.

[0045] The present invention can solve the problem that the outline of spark discharge bubbles is difficult to distinguish, and the time and space control of spark discharge bubbles can be realized by using a programmable pulse discharge power supply; the method adopted by the present invention is simple and effective, and is convenient for the rapid popularization of technology.

[0046] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0047] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A bubble space-time control and observation system during electrospark machining, characterized in that: include: A power supply, wherein the power supply is a programmable pulse discharge power supply, and the positive and negative electrodes of the power supply are respectively connected to the first electrode and the second electrode; A discharge platform (1), wherein a height adjustment component and a transparent resin block (2) are arranged on the discharge platform (1); the distance between the first electrode and the second electrode is adjusted by the height adjustment component, the second electrode is embedded in the transparent resin block (2), and the second electrode is an electrode wire (14); a groove is provided on the top of the transparent resin block (2), a working liquid (3) is contained in the groove, and the working liquid (3) is arranged between the first electrode and the second electrode; A high-speed camera (4), the high-speed camera (4) being used to photograph bubbles generated in the working fluid (3), the photographing speed of the high-speed camera (4) being 20,000 frames per second to 30,000 frames per second; It also includes a filter (5), which is placed at the lens of the high-speed camera (4), and the filter (5) only allows light of one wavelength to pass through; It also comprises a laser (6), which is used to irradiate bubbles generated in the working fluid (3); the light emitted by the laser (6) is monochromatic light, and the light emitted by the laser (6) can pass through the filter (5).

2. The bubble time-space control and observation system during EDM according to claim 1, characterized in that: The height adjustment component comprises a cylindrical rod (7) fixedly mounted on one end of the top of the discharge platform (1), the cylindrical rod (7) being arranged perpendicularly to the discharge platform (1); a cross bar (8) is slidably sleeved on the cylindrical rod (7), both ends of the cross bar (8) being installed with flower-shaped knobs (9), the first electrode being detachably mounted on the cross bar (8) via the flower-shaped knob (9), the first electrode being arranged correspondingly to the second electrode in the transparent resin block (2), the cross bar (8) being fixedly matched with the cylindrical rod (7) via the flower-shaped knob (9), and the cross bar (8) being arranged parallel to the discharge platform (1).

3. The bubble time-space control and observation system during EDM according to claim 2, characterized in that: The discharge platform (1) is a marble platform.

4. The bubble time-space control and observation system during EDM according to claim 2, characterized in that: A circular hole is provided in the middle of the discharge platform (1), an annular fill light (10) is fixedly installed in the circular hole, and the transparent resin block (2) is arranged corresponding to the circular hole.

5. The bubble time-space control and observation system during EDM according to claim 4, characterized in that: A support frame (11) is installed at the bottom end of the discharge platform (1), an L-shaped bracket is installed inside the support frame (11), the high-speed camera (4) is installed on the L-shaped bracket, and the lens of the high-speed camera (4) is arranged corresponding to the circular hole.

6. The bubble time-space control and observation system during EDM according to claim 1, characterized in that: The first electrode is a screw micrometer (12), and the screw micrometer (12) is used to control the gap size between the first electrode and the second electrode.

7. The bubble time-space control and observation system during EDM according to claim 4, characterized in that: A support plate (13) is provided on the discharge platform (1), the support plate (13) is an acrylic plate, the support plate (13) is arranged corresponding to the circular hole, and the transparent resin block (2) is placed on the support plate (13).

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