Electric arc milling device and method adopting sheet electrode direct injection liquid supply

Abstract

The invention provides an electric arc milling device and method adopting a sheet electrode for direct injection liquid supply, and relates to the field of electrical discharge machining, the electric arc milling device comprises a liquid storage tank, the liquid storage tank is provided with a liquid storage cavity, the liquid storage cavity is provided with a liquid outlet in the bottom of the liquid storage tank, and the liquid storage cavity is used for storing working liquid; the sheet-shaped electrode is used for being connected with a pulse power supply and arranged at the liquid outlet, the sheet-shaped electrode is provided with a working face, the working face is used for being close to the to-be-machined face of a workpiece, and working liquid sprayed out of the liquid outlet is attached to the working face to flow downwards and conducts arc disturbing or arc breaking on an electric arc generated between the to-be-machined face and the working face. The sheet electrode can better guide the working fluid to flow downwards along the working face, the working fluid moves linearly, steering kinetic energy loss is avoided, the high-flow-speed working fluid can be obtained, and the high heat removal effect is achieved.

Description

Technical Field

[0001] The invention relates to the field of electric discharge machining, and in particular to an arc milling device and method using a sheet electrode to directly spray liquid. Background Art

[0002] Electrode milling is a new manufacturing technology developed in recent years. At present, the electrodes of arc milling basically follow the form of CNC milling tools, that is, the electrodes of rotating bodies are used for discharge. However, the purpose of tool rotation in CNC milling is to make the cutting edge obtain linear velocity to realize milling of the workpiece, while the arc uses the high-temperature melting and vaporization of metal generated by large current discharge to realize milling of metal workpieces. That is, arc milling does not require contact, and the electrode does not need to rotate to obtain linear velocity in arc milling.

[0003] During the arc milling process, high-flow working fluid needs to be sprayed into the machining gap to quickly discharge the high heat generated during machining. However, with the existing external spray or internal injection fluid supply method, the working fluid often undergoes one or more turns and changes direction before being sprayed onto the surface to be machined at a certain angle, and then turns direction to enter the machining gap, resulting in large speed loss and poor heat removal effect. Summary of the invention

[0004] The present invention provides an arc milling device and method using a sheet electrode to directly spray liquid supply, the purpose of which is to provide a new type of arc milling device, thereby reducing device cost and precision requirements, improving heat removal effect, and optimizing arc milling technology.

[0005] In order to achieve the above-mentioned object, an embodiment of the present invention provides an arc milling device using a sheet electrode to directly spray liquid, comprising:

[0006] A liquid storage tank, comprising a liquid storage cavity, wherein a liquid outlet is formed at the bottom of the liquid storage tank, and the liquid storage cavity is used to store working fluid;

[0007] A sheet electrode for connecting a pulse power supply is arranged at a liquid outlet, wherein the sheet electrode has a working surface, and the working surface is used to be close to the surface to be processed of the workpiece. The working fluid ejected from the liquid outlet adheres to the working surface and flows downward at a high speed. In addition to serving as a working medium for arc discharge, the working fluid also disturbs or breaks the arc generated between the surface to be processed of the workpiece and the working surface of the sheet electrode.

[0008] Preferably, the sheet electrode has a hollow cavity therein, and a plurality of fluid replenishing holes are arranged on the working surface along the length direction of the sheet electrode, the angle between the fluid replenishing holes and the working surface is an acute angle, and the fluid replenishing holes are connected with the liquid storage cavity through the hollow cavity.

[0009] Preferably, a surface 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, a curved surface, or a combination of a curved surface and a plane.

[0011] Preferably, the liquid outlet is slit-shaped, the width of the liquid outlet is the same as the width of the sheet electrode, the opening of the liquid outlet is 0.1-5 mm, and the liquid outlet vertically passes through the bottom of the liquid storage tank.

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

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

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

[0015] The present application also provides a method, using the aforementioned arc milling device using a sheet electrode direct injection liquid supply, comprising:

[0016] Move the sheet electrode downward to the rear of the surface to be processed;

[0017] The working fluid adheres to the sheet electrode and flows downward and enters between the surface to be processed and the working surface;

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

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

[0020] Preferably, the sheet electrode is fed by vibration.

[0021] The above scheme of the present invention has the following beneficial effects:

[0022] First, the present application adopts a sheet electrode, which does not need to be rotated during 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 fluid to flow downward along the working surface. The working fluid is directly sprayed into the processing gap formed by the working surface and the surface to be processed. There is no loss of steering kinetic energy, and a high flow rate of working fluid can be obtained to achieve a high heat removal effect.

[0024] Third, high-flow working fluid is directly sprayed into the processing gap, which can better achieve arc disturbance or arc breaking. The high-speed flowing working fluid is used to flush the arc back and forth on the surface to be processed, expanding the arc action area and avoiding the burning of the workpiece due to the continuous action of the arc on a certain point.

[0025] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a working schematic diagram of the present invention;

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

[0028] Figure 3 yes Figure 2 Enlarged schematic diagram of part A

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

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

[0031] Figure 5 is a schematic cross-sectional view of a sheet electrode;

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

[0033] [Description of Reference Numerals]

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

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

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

[0037] 40-Mounting parts,

[0038] 50-sliding unit,

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

[0040] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0041] like Figure 1-6As shown, an embodiment of the present invention provides an arc milling device using a sheet electrode for direct injection of liquid supply, comprising a liquid storage tank 10 and a sheet electrode 20. The liquid storage tank 10 has a liquid storage cavity, and 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 a working fluid, and the working fluid can be ejected at a high speed through the liquid outlet 11. Preferably, the working fluid is a commercially available oil-based working fluid. The aforementioned sheet electrode 20 is used to connect to a pulse power supply. Under the action of the pulse power supply, an arc is generated between the sheet electrode 20 and the surface 31 to be processed of the workpiece 30, thereby realizing arc processing of the workpiece 30. When the sheet electrode 20 moves continuously along a preset trajectory, the milling processing of the workpiece is realized. The sheet electrode 20 is vertically arranged at the liquid outlet 11, and the sheet electrode 20 has a working surface 21, which faces the surface 31 to be processed of the workpiece 30. The sprayed working liquid flows downward along the working surface 21, and disturbs or interrupts the arc generated between the surface 31 to be processed of the workpiece and the working surface 21 of the sheet electrode 20.

[0042] In the present application, the sheet electrode 20 does not need to perform rotational motion during the arc milling process, but only moves along the feed direction to complete the arc milling, thereby reducing the requirements for the rotation accuracy and dynamic balance of the machine tool, reducing the cost of the machine tool and the difficulty of manufacturing the electrode. In addition, the sheet electrode 20 adopts a direct injection liquid supply method that can better guide the working fluid to flow straight down along the working surface 21. During the movement, the working fluid has no loss of turning kinetic energy, forming a continuous waterfall strong spray liquid, and obtaining a high flow rate, thereby achieving rapid heat removal from the processing surface 31, solving the problems of burns, increased deformation, thickening of the heat-affected layer, and more and deeper microcracks in the processing of the metal workpiece 30 caused by the huge heat generated by the electric arc. At the same time, rapid heat removal also greatly reduces the loss of the sheet electrode 20.

[0043] While dissipating heat, the working fluid continuously flushes the arc to disturb or break the arc. The high-speed fluid flushing causes the arc to sweep back and forth on the surface to be processed 31, expanding the effective area and preventing the arc from continuously acting on a certain point and thus ablating the workpiece 30.

[0044] Furthermore, the sheet electrode 20 has a hollow cavity 22, which is arranged along the length direction of the sheet electrode 20. The upper end of the hollow cavity 22 is open and the lower end is closed. The working surface 21 is provided with a plurality of fluid replenishment holes 23 along the length direction of the sheet electrode 20. The angle α between the fluid replenishment hole 23 and the working surface 21 is an acute angle. The fluid replenishment hole 23 is connected to the liquid storage cavity through the hollow cavity 22.

[0045] In the present application, part of the working fluid enters the hollow cavity 22 and is sprayed from the inside of the sheet electrode 20 through the fluid replenishment hole 23 to between the surface to be processed 31 and the working surface 21. This can cope with the problems of large cutting depth, increased liquid resistance, and reduced flow rate of the working fluid flowing along the working surface 21, thereby ensuring high flow rate operation of the working fluid.

[0046] In the present application, the liquid outlet 11 includes a rear base surface and a front base surface, and the rear base surface and the front base surface are arranged oppositely, wherein the rear base surface is a side of the liquid outlet 11 away from the workpiece 30, and the rear base surface is coplanar with the working surface 21. The coplanar arrangement of the rear base surface and the working surface 21 can effectively ensure that the working liquid remains in a downward straight spray state during the spraying process, and avoids the deflection of the working liquid. The working surface 21 is a plane, a curved surface, or a combination of a plane and a curved surface.

[0047] The aforementioned liquid outlet 11 is in the shape of a slit, the width of the liquid outlet 11 is the same as the width of the sheet electrode 20, the opening is between 0.1-5 mm, 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 sprays out of the liquid outlet 11. Preferably, the bottom wall thickness of the liquid storage tank 10 is greater than 5 mm, so as to ensure that the working liquid is reliably guided to be directly sprayed close to the working surface 21.

[0048] In order to ensure that the working surface 21 is coplanar with the rear base surface, a mounting member 40 is provided at the bottom of the liquid storage tank 10 , and the sheet electrode 20 is mounted on the mounting member 40 , with the working surface 21 facing the surface to be processed 31 .

[0049] In the first embodiment of the present application, an angle iron is provided at the bottom of the liquid storage tank 10, one end of the angle iron is fixed to the bottom of the liquid storage tank 10, and the other end is used to fix the sheet electrode 20, and the working surface 21 of the sheet 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 bottom of the liquid storage tank 10 on the side away from the workpiece 30, and the protrusion is the mounting portion 40. The protrusion is provided with a groove for accommodating the sheet electrode 20. When the sheet electrode 20 is installed in the groove, the working surface 21 of the sheet electrode 20 is coplanar with the rear base surface of the liquid outlet 11. When the sheet electrode 20 is installed in the groove, it can be fixed by front fixing or side fixing. Preferably, the fixing of the sheet electrode 20 does not interfere with the flow of the working fluid in the hollow cavity 22.

[0051] In the third embodiment of the present application, the upper end of the sheet electrode 20 is inserted into the liquid storage chamber through the liquid outlet 11. At this time, the upper end of the working surface 21 of the sheet electrode 20 guides the working liquid to flow along the lower end of the working surface 21, and can also ensure that the working liquid is directly sprayed along the working surface 21.

[0052] In the present application, a sliding unit 50 is provided on the side of the liquid outlet 11 close to the front base surface. The sliding unit 50 can change the distance between the sliding unit 50 and the sheet electrode 20 by sliding, thereby adjusting the cross-sectional size of the working liquid spraying, and even realizing the opening and closing of the liquid outlet 11. The sliding unit 50 can be driven by existing technologies, 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 pulsating liquid supply, fluid arc disturbance, and arc breaking.

[0053] In order to achieve the effect of pulsating liquid supply, the liquid storage tank 10 is also connected to 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 injection state of the working fluid at the liquid outlet 11, and the injection state includes the injection speed, the injection frequency, etc. In the present application, the liquid inlet control unit 60 can be a valve that can be automatically controlled, or it can be a jet oscillator. On the one hand, the liquid inlet control unit 60 indirectly adjusts the injection state by replenishing the liquid storage chamber filled with the working fluid. On the other hand, if the liquid inlet control unit 60 is arranged at the liquid outlet 11, it will interfere with the injection speed of the working fluid, and even cause the working fluid to be deflected during the injection process.

[0054] The present application also provides a method, which is applied to the aforementioned arc milling device using a sheet electrode direct injection liquid supply, comprising the following steps:

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

[0056] The working liquid adheres to the sheet electrode 20 and flows downward and enters between the surface to be processed 31 and the working surface 21. The pressure of the working liquid is between 0.2MP and 2MP.

[0057] After the working fluid flows, the sheet electrode 20 is connected to a pulse power source and fed forward to perform arc milling on the to-be-machined surface 31 of the workpiece 30 .

[0058] During the processing, the sliding unit 50 and / or the liquid inlet control unit 60 can be controlled to control the injection state of the working fluid to meet the processing requirements of fluids with different arc intensities, arc disturbances, and arc breaking.

[0059] The feeding method of the sheet arc can also be vibration feeding. Vibration feeding refers to periodically changing the distance between the surface to be processed 31 and the working surface 21. The feeding method of vibration feeding can effectively dissipate heat. Vibration feeding can also be coordinated with a pulse power supply. When the sheet electrode 20 is fed, the pulse power supply is turned on for discharge, and the power supply is turned off when the sheet electrode 20 is retracted.

[0060] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An arc milling device using a sheet electrode to directly spray liquid, characterized in that: include: A liquid storage box (10) having a liquid storage cavity, wherein a liquid outlet (11) is formed at the bottom of the liquid storage box (10), and the liquid storage cavity is used to store working fluid; A sheet electrode (20) for connecting to a pulse power source is arranged at a liquid outlet (11), the sheet electrode (20) having a working surface (21), the working surface (21) being used to approach a surface to be processed (31) of a workpiece (30), the working liquid ejected from the liquid outlet (11) adheres to the working surface (21) and flows downward to disturb or interrupt an arc generated between the surface to be processed (31) and the working surface (21).

2. The arc milling device using sheet-shaped electrode direct injection liquid supply according to claim 1 is characterized in that: The sheet electrode (20) has a hollow cavity (22) therein, and a plurality of liquid replenishing holes (23) are arranged on the working surface (21) along the length direction of the sheet electrode (20), wherein the angle between the liquid replenishing holes (23) and the working surface (21) is an acute angle, and the liquid replenishing holes (23) are connected to the liquid storage cavity through the hollow cavity (22).

3. The arc milling device using sheet-shaped electrode direct injection liquid supply according to claim 1, characterized in that: The surface of the liquid outlet (11) away from the workpiece (30) is a rear base surface, and the rear base surface is coplanar with the working surface (21).

4. The arc milling device using sheet-shaped electrodes for direct liquid injection according to claim 3 is characterized in that: The working surface (21) is a plane, a curved surface, or a combination of a curved surface and a plane.

5. The arc milling device using sheet-shaped electrode direct injection liquid supply according to claim 3 is characterized in that: The liquid outlet (11) is slit-shaped, the width of the liquid outlet is the same as the width of the sheet electrode (20), the opening of the liquid outlet (11) is 0.1-5 mm, and the liquid outlet (11) vertically penetrates the bottom of the liquid storage tank (10).

6. The arc milling device using sheet-shaped electrodes for direct liquid injection according to claim 3, characterized in that: A mounting member (40) is provided at the bottom of the liquid storage tank (10), and the sheet electrode (20) is mounted on the mounting member (40) with the working surface (21) being coplanar with the rear base surface.

7. The arc milling device using sheet-shaped electrodes for direct liquid injection according to claim 3, characterized in that: A side of the liquid outlet (11) close to the working surface (21) is a front base surface, and a slidable sliding unit (50) is provided on a side of the liquid storage tank (10) close to the front base surface, and the sliding unit (50) changes the distance between the sliding unit and the sheet electrode (20) by sliding.

8. The arc milling device using sheet-shaped electrodes for direct liquid injection according to claim 1, characterized in that: The liquid storage box (10) is connected to a liquid inlet channel, and a liquid inlet control unit (60) is provided on the liquid inlet channel. The liquid inlet control unit (60) is used to control the injection speed and injection frequency of the working liquid at the liquid outlet (11).

9. A method, using the arc milling device using a sheet electrode direct injection liquid supply as claimed in any one of claims 1 to 8, characterized in that: include: The sheet electrode (20) is moved to face the rear of the surface to be processed (31) of the workpiece; The working liquid is sprayed downwardly in contact with the sheet electrode (20) and enters between the to-be-processed surface (31) of the workpiece and the working surface (21) of the sheet electrode (20); The sheet electrode (20) is connected to a pulse power supply; The sheet electrode (20) is fed forward to perform arc milling on the to-be-machined surface (31) of the workpiece.

10. The method according to claim 9, characterized in that: The sheet-shaped electrode (20) is fed along the feeding path in a vibration manner.

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