An arc milling device and method using a sheet electrode direct jet feed

Abstract

The application provides an arc milling device and method using a sheet electrode for direct jet liquid supply, and relates to the field of electric discharge machining, and comprises: a liquid storage tank with a liquid storage cavity, wherein the liquid storage cavity is provided with a liquid outlet at the bottom of the liquid storage tank, and the liquid storage cavity is used for storing working liquid; a sheet electrode connected to a pulse power source is arranged at the liquid outlet, the sheet electrode has a working surface, the working surface is used for being close to a workpiece surface to be machined, and working liquid jetted out of the liquid outlet flows downward along the working surface and performs arc disturbance or arc breaking on an arc generated between the surface to be machined and the working surface. The sheet electrode can better guide the working liquid to flow downward along the working surface, the working liquid moves in a straight line, there is no turning kinetic energy loss, high-flow-speed working liquid can be obtained, and high heat dissipation effect is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electrical discharge machining, in particular to an arc milling device and method using a sheet electrode for direct jet liquid supply. BACKGROUND

[0002] Electrode milling is a new manufacturing technology developed in recent years. The electrode for arc milling is basically used in the form of numerical control milling tools, that is, a rotary electrode is used for discharge. However, the purpose of tool rotation in numerical control milling is to make the cutting edge obtain linear velocity to realize milling of the workpiece. The arc is high-temperature molten and vaporized metal generated by large current discharge, which realizes milling of the metal workpiece, that is, the arc milling does not require contact. In the arc milling, the electrode does not need to rotate to obtain linear velocity.

[0003] In the process of arc milling, high flow rate working liquid needs to be sprayed into the machining gap to quickly discharge the high heat generated during machining. However, in the existing external spraying or internal jetting liquid supply mode, the working liquid often changes direction once or multiple times and then is sprayed at a certain angle to the surface to be machined, and then changes direction again to enter the machining gap. The speed loss is large, and the heat dissipation effect is poor. SUMMARY

[0004] The present application provides an arc milling device and method using a sheet electrode for direct jet liquid supply, which aims to provide a new type of arc milling device, thereby reducing the cost and precision requirements of the device, improving the heat dissipation effect and optimizing the arc milling process.

[0005] In order to achieve the above purpose, an embodiment of the present application provides an arc milling device using a sheet electrode for direct jet liquid supply, comprising:

[0006] A liquid storage tank having a liquid storage cavity, the liquid storage cavity is formed with a liquid outlet at the bottom of the liquid storage tank, and the liquid storage cavity is used for storing working liquid;

[0007] A sheet electrode for connecting a pulse power supply is arranged at the liquid outlet, the sheet electrode has a working surface, the working surface is used for being close to the surface to be machined of the workpiece, the working liquid sprayed out of the liquid outlet flows downward at high speed along the working surface, and the working liquid not only serves as a working medium for arc discharge, but also disturbs or breaks the arc generated between the surface to be machined of the workpiece and the working surface of the sheet electrode.

[0008] Preferably, the sheet electrode has a hollow cavity, a plurality of liquid supplement holes are arranged on the working surface along the length direction of the sheet electrode, the included angle between the liquid supplement hole and the working surface is an acute angle, and the liquid supplement hole is in communication with the liquid storage cavity through the hollow cavity.

[0009] Preferably, the side of the liquid outlet away from the workpiece is a rear base surface, and the rear base surface is coplanar with the working surface.

[0010] Preferably, the working surface is a plane, an arc surface or a combination of an arc surface and a plane.

[0011] Preferably, the liquid outlet is in the shape of a slit, the width of the liquid outlet is the same as the width of the sheet electrode, the opening of the liquid outlet is 0.1-5mm, and the liquid outlet vertically penetrates the bottom of the liquid storage tank.

[0012] Preferably, the bottom of the liquid storage tank is provided with a mounting part, and the sheet electrode is mounted on the mounting part and the working surface is coplanar with the rear base surface.

[0013] Preferably, one side of the liquid outlet close to the working surface is the front base surface, and a slidable sliding unit is arranged on the side of the liquid storage tank close to the front base surface, and the sliding unit changes the distance between the sheet electrode by sliding.

[0014] Preferably, a liquid inlet channel is communicated with the liquid storage tank, and a liquid inlet control unit is arranged on the liquid inlet channel, and the liquid inlet control unit is used to control the injection speed and injection frequency of the working liquid at the liquid outlet.

[0015] The application also provides a method using the arc milling device with a sheet electrode for direct injection of working liquid, comprising:

[0016] Moving the sheet electrode downward to the rear of the machined surface;

[0017] The working liquid flows downward along the sheet electrode and enters the gap between the machined surface and the working surface;

[0018] The sheet electrode is connected to the pulse power supply;

[0019] The sheet electrode is fed forward to perform arc milling on the machined surface.

[0020] Preferably, the feeding mode of the sheet electrode is vibration feeding.

[0021] The above scheme of the application has the following advantages:

[0022] First, the sheet electrode is used in the application, and the sheet electrode does not need to rotate in arc milling, thereby reducing the requirements for the rotation accuracy and dynamic balance of the machine tool.

[0023] Second, the sheet electrode can better guide the working liquid to flow downward along the working surface, and the working liquid directly sprays the machining gap formed by the working surface and the machined surface, without turning kinetic energy loss, so that high-speed working liquid can be obtained to achieve high heat dissipation effect.

[0024] Third, the high flow rate of working fluid direct injection processing gap, can better realize the arc or broken arc, using high-speed flow of working fluid scouring so that the arc in the processing surface to and fro, expand the arc area of action, to avoid the arc due to continuous effect on a point and ablation workpiece.

[0025] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is the working schematic diagram of the present application;

[0027] Figure 2 is the working schematic diagram of the sheet electrode with hollow cavity;

[0028] Figure 3 is Figure 2 enlarged schematic diagram of A part in

[0029] Figure 4a is the fixing mode of sheet electrode in the first embodiment;

[0030] Figure 4b is the fixing mode of sheet electrode in the second embodiment;

[0031] Figure 5 is the cross-sectional schematic diagram of sheet electrode;

[0032] Figure 6 is the schematic diagram of sliding unit.

[0033]

BRIEF DESCRIPTION OF DRAWINGS

[0034] 10-liquid storage tank, 11-liquid outlet,

[0035] 20-sheet electrode, 21-working surface, 22-hollow cavity, 23-liquid supplement hole

[0036] 30-workpiece, 31-surface to be processed,

[0037] 40-mounting piece,

[0038] 50-sliding unit,

[0039] 60-liquid inlet control unit, DETAILED DESCRIPTION

[0040] In order to make the technical problems, technical solutions and advantages of the present application more clear, the following will be described in detail in conjunction with the drawings and specific embodiments.

[0041] As Figures 1-6As shown, the embodiment of the present application provides an arc milling device with a sheet electrode for direct liquid supply, comprising a liquid storage tank 10 and a sheet electrode 20, the liquid storage tank 10 has a liquid storage cavity, the liquid storage cavity forms a liquid outlet 11 at the bottom of the liquid storage tank 10, the liquid storage cavity is used to store working liquid, the working liquid can be sprayed out at high speed through the liquid outlet 11, preferably, the working liquid is commercially available oil-based working liquid. The aforementioned sheet electrode 20 is used to connect the pulse power supply, under the action of the pulse power supply, an electric arc is generated between the sheet electrode 20 and the surface to be machined 31 of the workpiece 30, thereby realizing arc machining of the workpiece 30, when the sheet electrode 20 continuously moves along the preset trajectory, the milling of the workpiece is realized. The sheet electrode 20 is vertically arranged at the liquid outlet 11, the sheet electrode 20 has a working surface 21, the working surface 21 faces the surface to be machined 31 of the workpiece 30, the sprayed working liquid flows downward along the working surface 21, and the electric arc generated between the surface to be machined 31 of the workpiece and the working surface 21 of the sheet electrode 20 is disturbed or broken.

[0042] In the present application, the sheet electrode 20 does not need to perform rotary motion during the arc milling process, but only moves along the feed direction to complete the arc milling, thereby reducing the requirements for the rotary precision and dynamic balance of the machine tool, reducing the cost of the machine tool and the difficulty of manufacturing the electrode. Moreover, the sheet electrode 20 adopts a direct liquid supply mode that can better guide the working liquid to flow downward along the working surface 21 in a straight line, the working liquid has no turning kinetic energy loss during the movement, a continuous waterfall strong jet liquid is formed, a high flow rate is obtained, thereby realizing rapid heat removal of the surface to be machined 31, solving the problems of burn, deformation increase, heat affected layer thickening of the metal workpiece 30 caused by the huge heat generated by the electric arc, and more and deeper micro cracks during machining, at the same time, rapid heat removal also greatly reduces the loss of the sheet electrode 20.

[0043] At the same time of heat removal, the working liquid continuously flushes the electric arc, realizes disturbance or breaking of the electric arc, the high-speed fluid flushing makes the electric arc sweep back and forth on the surface to be machined 31, expands the action area, avoids the electric arc from continuously acting on a certain point to ablate the workpiece 30.

[0044] Further, the sheet electrode 20 has a hollow cavity 22, the hollow cavity 22 is arranged along the length direction of the sheet electrode 20, the upper end of the hollow cavity 22 is open, the lower end is closed, the working surface 21 is provided with a plurality of liquid supplement holes 23 along the length direction of the sheet electrode 20, the included angle α between the liquid supplement hole 23 and the working surface 21 is an acute angle, the liquid supplement hole 23 is communicated with the liquid storage cavity through the hollow cavity 22.

[0045] In the present application, part of the working liquid enters the hollow cavity 22, and is sprayed from the inside of the sheet-shaped electrode 20 to the working surface 21 through the liquid supplementing hole 23, which can deal with the problem of large cutting depth, increased liquid resistance and reduced flow rate of the working liquid along the working surface 21, thereby ensuring high flow rate of the working liquid.

[0046] In the present application, the liquid outlet 11 comprises a rear base surface and a front base surface, which are oppositely arranged, wherein the rear base surface is the surface of the liquid outlet 11 away from the workpiece 30, and the rear base surface is coplanar with the working surface 21. The arrangement of the rear base surface coplanar with the working surface 21 can effectively ensure that the working liquid maintains a straight downward spraying state during the spraying process, avoiding deflection of the working liquid. The working surface 21 is a plane, an arc surface or a combination of a plane and an arc surface.

[0047] The aforementioned liquid outlet 11 is in the form of a slit, the width of the liquid outlet 11 is the same as the width of the sheet-shaped electrode 20, the opening is between 0.1-5mm, and the liquid outlet 11 vertically penetrates the bottom of the liquid storage tank 10. The vertical penetration of the liquid outlet 11 helps to reduce the kinetic energy loss when the working liquid is sprayed out of the liquid outlet 11. Preferably, the thickness of the bottom wall of the liquid storage tank 10 is greater than 5mm, thereby ensuring that the working liquid can be reliably guided to spray straight against the working surface 21.

[0048] To ensure that the working surface 21 is coplanar with the rear base surface, a mounting member 40 is arranged at the bottom of the liquid storage tank 10, the sheet-shaped electrode 20 is mounted on the mounting member 40, and the working surface 21 faces the machined surface 31.

[0049] In the first embodiment of the present application, an angle iron is arranged at the bottom of the liquid storage tank 10, one end of the angle iron is fixed at the bottom of the liquid storage tank 10, and the other end is used to fix the sheet-shaped electrode 20, and the working surface 21 of the sheet-shaped electrode 20 is coplanar with the rear base surface of the liquid outlet 11.

[0050] In the second embodiment of the present application, a protrusion is formed on the side of the bottom of the liquid storage tank 10 away from the workpiece 30, which is the mounting member 40, and a recess for accommodating the sheet-shaped electrode 20 is arranged on the protrusion. When the sheet-shaped electrode 20 is mounted in the recess, the working surface 21 of the sheet-shaped electrode 20 is coplanar with the rear base surface of the liquid outlet 11. The sheet-shaped electrode 20 can be fixed in the recess by front fixation or side fixation. Preferably, the fixation of the sheet-shaped electrode 20 does not interfere with the flow of the working liquid in the hollow cavity 22.

[0051] In the third embodiment of the present application, the upper end of the sheet-shaped electrode 20 is inserted into the liquid storage cavity through the liquid outlet 11, at this time, the upper end of the working surface 21 of the sheet-shaped electrode 20 guides the working liquid to flow along the lower end of the working surface 21, which also ensures that the working liquid sprays straight along the working surface 21.

[0052] In the present application, the liquid outlet 11 is provided with a sliding unit 50 on the side close to the front base surface. The sliding unit 50 can change the distance between the sliding unit 50 and the sheet-shaped electrode 20 by sliding, so as to adjust the cross-sectional size of the working liquid ejection, and even realize the opening and closing of the liquid outlet 11. The sliding unit 50 can be driven by the existing technology, such as using a lead screw assembly, an electric push rod, etc. The setting of the sliding unit 50 can control the channel of the working liquid, realize the pulsating liquid supply, fluid disturbance arc, and arc breaking.

[0053] In order to realize the effect of pulsating liquid supply, the liquid storage tank 10 is also communicated with a liquid inlet channel, and a liquid inlet control unit 60 is arranged on the liquid inlet channel. The liquid inlet control unit 60 controls the ejection state of the working liquid at the liquid outlet 11, including the ejection speed, ejection frequency, etc. In the present application, the liquid inlet control unit 60 can be a valve capable of automatic control, or a fluidic oscillator. On the one hand, the liquid inlet control unit 60 indirectly adjusts the ejection state by supplementing the liquid storage cavity filled with working liquid. On the other hand, if the liquid inlet control unit 60 is arranged at the liquid outlet 11, it will interfere with the ejection speed of the working liquid, and even cause the working liquid to deflect during ejection.

[0054] The present application also provides a method applied to the above-mentioned arc milling device using a sheet-shaped electrode for direct liquid supply, which comprises the following steps:

[0055] The arc milling device moves downward to ensure that the sheet-shaped electrode 20 moves to the rear of the machined surface 31;

[0056] The working liquid flows downward along the sheet-shaped electrode 20 and enters between the machined surface 31 and the working surface 21, and the pressure of the working liquid is between 0.2MP and 2MP;

[0057] After the working liquid flows, the sheet-shaped electrode 20 is connected to the pulse power supply and feeds forward to perform arc milling on the machined surface 31 of the workpiece 30.

[0058] During the machining process, the sliding unit 50 and / or the liquid inlet control unit 60 can be controlled to control the ejection state of the working liquid, so as to meet the machining requirements of different arc intensities, fluid, arc disturbance, and arc breaking.

[0059] The feeding mode of the sheet-shaped arc can also be vibration feeding. The vibration feeding refers to periodically changing the distance between the machined surface 31 and the working surface 21. The vibration feeding mode can effectively remove heat. The vibration feeding can also be matched with the pulse power supply. When the sheet-shaped electrode 20 feeds, the pulse power supply is turned on to discharge. When the sheet-shaped electrode 20 retreats, the power supply is turned off.

[0060] The above is the preferred embodiment of the present application, it should be noted that for those skilled in the art, without departing from the principles described in the present application, can also be made several improvements and refinements, these improvements and refinements should also be considered the scope of protection of the present application.

Claims

1. An arc milling device employing a sheet electrode direct feed supply, characterized by, The utility model relates to a kind of arc milling machine, including: Liquid storage tank (10) with liquid storage chamber, the liquid storage chamber is formed with liquid outlet (11) in the bottom of the liquid storage tank (10), the liquid storage chamber is used to store working fluid; Sheet electrode (20) for connecting pulse power supply, it is arranged at liquid outlet (11), the sheet electrode (20) has working surface (21), the working surface (21) is used to be close to the surface (31) to be processed of workpiece (30), working fluid ejected from the liquid outlet (11) is adhered to the working surface (21) and flows downward and generates arc between the surface (31) to be processed and the working surface (21) and is disturbed or broken arc; It is characterized in that: the side of the liquid outlet (11) close to the working surface (21) is front base surface, slidable sliding unit (50) is arranged on the side of the liquid storage tank (10) close to front base surface, the distance between the sliding unit (50) and the sheet electrode (20) is changed by sliding.

2. The apparatus according to claim 1, wherein the apparatus is an arc milling apparatus using a sheet electrode direct-jet supply of liquid. The sheet electrode (20) has hollow cavity (22) inside, and a plurality of liquid supplementing holes (23) are arranged on the working surface (21) along the length direction of the sheet electrode (20), the included angle between the liquid supplementing hole (23) and the working surface (21) is acute, and the liquid supplementing hole (23) is communicated with the liquid storage chamber through the hollow cavity (22).

3. The apparatus according to claim 1, wherein the apparatus is characterized by: The side of the liquid outlet (11) away from workpiece (30) is rear base surface, and the rear base surface is coplanar with the working surface (21).

4. The apparatus according to claim 3, wherein the apparatus is characterized by: The working surface (21) is plane, arc surface or the combination of arc surface and plane.

5. The apparatus according to claim 3, wherein the apparatus is characterized by: The liquid outlet (11) is slit-shaped, the width of the liquid outlet is same with the width of the sheet electrode (20), the opening of the liquid outlet (11) is 0.1-5mm, and the liquid outlet (11) vertically penetrates the bottom of the liquid storage tank (10).

6. The apparatus according to claim 3, wherein the apparatus is characterized by: The bottom of the liquid storage tank (10) is provided with mounting part (40), and the sheet electrode (20) is mounted on the mounting part (40) and the working surface (21) is coplanar with the rear base surface.

7. The apparatus according to claim 1, wherein the apparatus is characterized by: The liquid storage tank (10) is communicated with liquid inlet channel, and the liquid inlet channel is provided with liquid inlet control unit (60), and the liquid inlet control unit (60) is used to control the ejection speed and frequency of working fluid in the liquid outlet (11).

8. A method of arc milling using the arc milling device of any one of claims 1 to 7, wherein the sheet electrode is directly fed to the arc milling device. Including: Mobile sheet electrode (20) is opposite the rear of the surface (31) to be processed of workpiece; Working fluid is adhered to the sheet electrode (20) and is ejected downward and enters between the surface (31) to be processed of workpiece and the working surface (21) of the sheet electrode (20); Sheet electrode (20) is connected to pulse power supply; Sheet electrode (20) is fed forward to the surface (31) to be processed of workpiece and is arc milled.

9. The method of claim 8, wherein: Sheet electrode (20) is vibrated along the feeding path.

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