Circuit structure of discharge absorption loop of electric spark forming machine tool

Abstract

The utility model discloses a circuit structure of a discharge absorption loop of an electric spark forming machine tool, which comprises a first absorption loop and a second absorption loop, the first absorption loop uses a power supply cathode to absorb reverse inductance electromotive force generated by an inductance device L1 at a workpiece end P3; the second absorption loop is connected with a negative electrode end P1 and an electrode end P2 of a diode D1 in the discharge circuit of the electric spark forming machine tool, and the second absorption loop uses a positive electrode of a power supply to absorb reverse inductive electromotive force generated by an inductor L1 at the electrode end P2, so that independent absorption of the electrode end P2 and a workpiece end P3 is realized; and a current loop is not formed between the electrode end P2 and the workpiece end P3, so that the adverse effect of secondary discharge on the workpiece is avoided, and the technical problem that the yield of finished workpieces is affected due to uncontrollable adverse effect caused by the fact that an existing absorption loop absorbs the reverse electromotive force of an inductor in a secondary discharge mode through the electrode end P2 and the workpiece end P3 is solved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the electric spark forming machine tool discharge control technical field, concretely relates to a circuit structure of electric spark forming machine tool discharge absorption loop. BACKGROUND

[0002] Electric spark forming machine tool is a kind of special processing machine tool, belongs to electric processing category, and its working principle is to apply pulse voltage between tool electrode and workpiece electrode, when the gap between the two electrodes is small to a certain extent (generally 0.01-0.1mm), the electric field intensity between the two electrodes will make working fluid (such as electric spark oil specially used for electric spark machining) ionize, break down and form discharge channel. Figure 2 When the machine tool is discharge machining, pulse control MOS tube Q1 is used to turn on and off, so that electrode P2 and workpiece P3 produce pressure difference discharge, when MOS tube Q1 is turned on, discharge starts, and when MOS tube Q1 is turned off, discharge stops.But since inductor L1 exists in the whole discharge loop, when MOS tube Q1 is turned off, a great pressure difference (between P4 and P3) is generated at the two ends of inductor due to inductive back electromotive force, so that the pressure difference between electrode P2 and workpiece P3 changes, affecting the consistency of discharge.

[0003] The discharge absorption loop currently adopted is that a resistance R3 and a diode D2 are used in series between the ground end P4 of discharge power supply and electrode P2 to form an absorption loop with electrode P2 and workpiece P3.The absorption loop can absorb the inductive back electromotive force generated by L1 in a short time when MOS tube Q1 is turned off, but since the inductive back electromotive force generated by L1 causes the pressure difference between electrode P2 and workpiece P3, the absorption loop absorbs the inductive back electromotive force by the way of secondary discharge generated by electrode P2 and workpiece P3, and the secondary discharge is an uncontrollable factor, which will have unpredictable effects on the whole discharge machining, especially when precision discharge machining is needed, which will cause damage to workpiece and lead to defective products. UTILITY MODEL CONTENTS

[0004] The utility model aims at providing a circuit structure of electric spark forming machine tool discharge absorption loop, and solves the technical problem that the absorption loop absorbs the inductive back electromotive force by the way of secondary discharge generated by electrode end P2 and workpiece end P3, which causes uncontrollable adverse effects and affects the yield of workpiece finished products.

[0005] To solve the above technical problems, the utility model discloses a kind of circuit structure of spark erosion machine tool discharge absorption loop, including first absorption loop and second absorption loop, the first absorption loop is by diode D7 and resistance R4 series connection, the second absorption loop is by voltage stabilizing diode D3, D4, D5 and diode D6, relay K3, K4 composition, the first absorption loop is connected with workpiece end P3 and power negative terminal P4, the first absorption loop is used to absorb the reverse inductance electromotive force generated by inductor device L1 at the workpiece end P3, the second absorption loop is connected with electrode end P2 and diode D1 negative terminal P1, diode D1 positive terminal is connected with power positive terminal, the second absorption loop is used to absorb the reverse inductance electromotive force generated by inductor device L1 at the electrode end P2.

[0006] As preferably, the connection relationship of spark erosion machine tool discharge circuit is: power positive terminal is connected with the positive terminal of diode D1, the negative terminal of diode D1 is connected with one end of resistance R1, the other end of resistance R1 is connected with the drain D of MOS tube Q1, the source S of MOS tube Q1 is connected with the electrode end P2, the electrode end P2 and the workpiece end P3 are immersed in working liquid and process workpiece, the workpiece end P3 is connected with one end of inductor device L1, the other end of inductor device L1 is connected with one end of resistance R2, the other end of resistance R2 is connected with the power negative terminal P4.

[0007] As preferably, resistance R2 is connected with relay K2 in parallel, and inductor device L1 is connected with relay K1 in parallel.

[0008] As preferably, MOS tube Q1 is turned on or turned off by pulse control.

[0009] As preferably, the connection relationship of the first absorption loop circuit is: the positive terminal of diode D7 is connected with the power negative terminal P4, the negative terminal of diode D7 is connected with one end of resistance R4, the other end of resistance R4 is connected with the workpiece end P3.When the MOS tube Q1 is turned off, the discharge stops, but since the inductor device L1 exists in the whole discharge circuit, a great voltage difference is generated between the two ends of inductor due to the reverse inductance electromotive force when the MOS tube Q1 is turned off, at this time, the first absorption loop is formed between the power negative terminal P4 and the workpiece end P3 through diode D7 and resistance R4, and the voltage difference between the power negative terminal P4 and the workpiece end P3 can be eliminated in a very short time by adjusting the resistance value of resistance R4, so that the reverse inductance electromotive force generated by inductor device L1 is absorbed, and the first absorption loop is absorbed through the power negative terminal.

[0010] As preferably, the connection relation of the second absorption circuit is that the negative pole end P1 of the diode D1 is connected to one end of the resistor R5, the other end of the resistor R5 is connected to the negative pole of the voltage stabilizing diode D3, the positive pole of the voltage stabilizing diode D3 is connected to the negative pole of the voltage stabilizing diode D4, the positive pole of the voltage stabilizing diode D4 is connected to the negative pole of the voltage stabilizing diode D5, the positive pole of the voltage stabilizing diode D5 is connected to the positive pole of the diode D6, and the negative pole of the diode D6 is connected to the electrode end P2.When the MOS tube Q1 is turned on, the discharge starts, and there is no voltage difference between the negative pole end P1 of the diode D1 and the electrode end P2, so the second absorption circuit does not play any role when the MOS tube Q1 is turned on; when the MOS tube Q1 is turned off, the discharge stops, but because the inductor L1 exists in the whole discharge circuit, a great voltage difference is generated between the inductor when the MOS tube Q1 is turned off due to the inductive counter electromotive force, and because the inductive capacitance exists between the electrode end P2 and the workpiece end P3 when discharging, when a great negative voltage is generated at the workpiece end P3, due to the bootstrap effect of the capacitor, the voltage of the electrode end P2 also becomes a great negative voltage, and the negative voltage of the electrode end P2 for a short time is beneficial to the electrode deionization, so that the MOS tube Q1 is turned off more quickly.

[0011] As preferably, the voltage stabilizing diode D3 is connected in parallel with the relay K3, and the voltage stabilizing diode D4 is connected in parallel with the relay K4.

[0012] Compared with the prior art, the utility model obtains the beneficial effect that:

[0013] The utility model discloses a kind of circuit structures of discharge absorption loop of electric spark forming machine tool, including first absorption loop and second absorption loop, the first absorption loop is formed by diode D7 and resistance R4 in series, the second absorption loop is formed by resistance R5, voltage stabilizing diode D3, D4, D5 and diode D6, relay K3, K4, the first absorption loop is connected with workpiece end P3 and power negative terminal P4, the first absorption loop uses power negative terminal to absorb the reverse inductive electromotive force generated by inductive device L1 at the workpiece end P3, the second absorption loop is connected with electrode end P2 and diode D1 negative terminal P1, the second absorption loop uses power positive terminal to absorb the reverse inductive electromotive force generated by inductive device L1 at the electrode end P2, the independent absorption of electrode end P2 and workpiece end P3 is realized, no current loop is formed between electrode end P2 and workpiece end P3, avoid the adverse effect of secondary discharge to workpiece, solve the uncontrollable adverse effect caused by the inductive reverse electromotive force of the secondary discharge of the existing absorption loop through electrode end P2 and workpiece end P3 to absorb thereby affect the yield of workpiece finished product Technical problem;Further, the second absorption loop uses hierarchical absorption mode, the number of voltage stabilizing diodes is controlled by controlling the on-off control of K3 and K4 relays, thereby the voltage of P1 and electrode end P2 is controlled, different discharge main voltage is adapted, and the beneficial effects of wide application range are achieved;The negative pressure generated at electrode end P2 in the second absorption loop is beneficial to electrode deionization, so that MOS tube Q1 is turned off more quickly, and the quick turn-off can more effectively prevent the loss of electrode, and has the beneficial effects of protecting processing electrode. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is the circuit structure schematic diagram of the utility model's electric spark forming machine tool discharge absorption loop.

[0015] Figure 2 It is the circuit structure schematic diagram of the background technology absorption loop.

[0016] Reference signs: 1-first absorption loop;2-second absorption loop. DETAILED DESCRIPTION

[0017] The utility model will be further described below in conjunction with the drawings and specific embodiments, but the described embodiment is only a part of the embodiment of the utility model, not all embodiments. Based on the embodiment in the utility model, all other embodiments obtained by the person skilled in the art without making creative labor belong to the scope of the utility model protection.

[0018] Please refer to Figures 1 to 2The application discloses a circuit structure of a discharge absorption circuit of an electric spark forming machine tool, and the connection relationship of the discharge circuit of the electric spark forming machine tool is as follows: a positive electrode of a power supply is connected with a positive electrode of a diode D1; a negative electrode P1 of the diode D1 is connected with one end of a resistor R1; the other end of the resistor R1 is connected with a drain D of a MOS tube Q1; a source S of the MOS tube Q1 is connected with an electrode P2; the electrode P2 and a workpiece end P3 are immersed in working liquid to process a workpiece; the workpiece end P3 is connected with one end of an inductive device L1; the other end of the inductive device L1 is connected with one end of a resistor R2; and the other end of the resistor R2 is connected with a negative electrode P4 of the power supply.

[0019] The circuit structure of the discharge absorption circuit of the electric spark forming machine tool comprises a first absorption circuit 100 and a second absorption circuit 200; the first absorption circuit 100 is composed of a diode D7 and a resistor R4 in series; and the second absorption circuit 200 is composed of a resistor R5, voltage stabilizing diodes D3, D4 and D5, a diode D6, relays K3 and K4; the first absorption circuit is connected with the workpiece end P3 and the negative electrode P4 of the power supply.

[0020] Further, the first absorption circuit 100 is used for absorbing a reverse inductive electromotive force generated by the inductive device L1 at the workpiece end P3; and the specific connection relationship of the first absorption circuit 100 with the discharge circuit of the electric spark forming machine tool is as follows: a positive electrode of the diode D7 is connected with the negative electrode P4 of the power supply of the discharge circuit of the electric spark forming machine tool; a negative electrode of the diode D7 is connected with one end of the resistor R4; and the other end of the resistor R4 is connected with the workpiece end P3. When the MOS tube Q1 is closed and the discharge is stopped, due to the inductive device L1 existing in the whole discharge circuit, a great pressure difference (namely, the pressure difference between the negative electrode P4 of the power supply and the workpiece end P3) is generated between the inductive device L1 when the MOS tube Q1 is closed due to the reverse inductive electromotive force; at this time, the first absorption circuit 100 formed by the diode D7 and the resistor R4 between the negative electrode P4 of the power supply and the workpiece end P3 can eliminate the pressure difference between the negative electrode P4 of the power supply and the workpiece end P3 in a very short time by adjusting the resistance value of the resistor R4, so as to absorb the reverse inductive electromotive force generated by the inductive device L1, and the first absorption circuit 100 is absorbed by the negative electrode of the power supply.

[0021] Further, the second absorption circuit 200 is used to absorb the reverse inductive electromotive force generated by the inductive device L1 at the electrode end P2. The specific connection relationship of the second absorption circuit 200 with the electric spark forming machine tool discharge circuit is that the negative electrode end P1 of the diode D1 is connected to one end of the resistor R5, the other end of the resistor R5 is connected to the negative electrode of the voltage stabilizing diode D3, the positive electrode of the voltage stabilizing diode D3 is connected to the negative electrode of the voltage stabilizing diode D4, the positive electrode of the voltage stabilizing diode D4 is connected to the negative electrode of the voltage stabilizing diode D5, the positive electrode of the voltage stabilizing diode D5 is connected to the positive electrode of the diode D6, the negative electrode of the diode D6 is connected to the electrode end P2, the voltage stabilizing diode D3 is connected in parallel with the relay K3, and the voltage stabilizing diode D4 is connected in parallel with the relay K4. When the MOS tube Q1 is turned on to start the discharge, there is no voltage difference between the negative electrode end P1 of the diode D1 and the electrode end P2, so the second absorption circuit does not play any role when the MOS tube Q1 is turned on. When the MOS tube Q1 is turned off to stop the discharge, a great voltage difference (i.e. between the negative electrode end P4 of the power supply and the workpiece end P3) is generated between the two ends of the inductive device L1 due to the reverse inductive electromotive force when the MOS tube Q1 is turned off. Since there is an inductive capacitance between the electrode end P2 and the workpiece end P3 during the discharge, when a great negative voltage is generated at the workpiece end P3, the voltage at the electrode end P2 will also become a great negative voltage due to the fact that the voltage across the capacitor cannot change abruptly (self-boosting effect of the capacitor). The short-time negative voltage at the electrode end P2 is conducive to the de-ionization of the electrode, so that the MOS tube Q1 can be turned off more quickly. At this time, a great voltage difference exists between the negative electrode end P1 of the diode D1 and the electrode end P2, i.e. a great voltage difference exists between the two ends of the second absorption circuit 200. According to the reverse breakdown conduction principle of the voltage stabilizing diode, by adjusting the number of the same type of voltage stabilizing diodes through the on-off of the relays K3 and K4, the voltage at the electrode end P2 can be quickly stabilized at a fixed value. Since the number of the voltage stabilizing diodes is fixed, no matter how severe the fluctuation of the negative voltage at the electrode end P2 is, the final result is that a fixed voltage difference exists between the negative electrode end P1 of the diode D1 and the electrode end P2. The second absorption circuit 200 realizes voltage absorption self-adaptation. The positive electrode end of the diode D1 is connected to the positive electrode end of the power supply, and the second absorption circuit 200 is absorbed through the positive electrode end of the power supply.

[0022] The first absorption circuit 100 and the second absorption circuit 200 make the workpiece and the electrode have independent absorption circuits respectively. The workpiece end P3 absorbs the inductive reverse electromotive force generated by L1 through the first absorption circuit 100, and the electrode end P2 absorbs the voltage difference generated by the inductive capacitance between the electrode end P2 and the workpiece end P3 through the second absorption circuit 200, so that there is no current loop between the electrode end P2 and the workpiece end P3, and the secondary discharge phenomenon will not occur.

[0023] The above only lists the specific embodiments of the present application. Obviously, the present application is not limited to the above embodiments, and there can be many similar modifications. All modifications that can be directly derived or thought of by those of ordinary skill in the art from the content disclosed in the present application should be considered as falling within the scope of the present application.

Claims

1. An electric circuit structure of a discharge absorption circuit of an electro discharge machine, characterized by comprising: The first absorption circuit (100) is connected with the workpiece end P3 and the power negative end P4, and the second absorption circuit (200) is connected with the electrode end P2 and the diode D1 negative end P1.

2. The circuit structure of the discharge absorption circuit of the electro discharge machine according to claim 1, wherein The connection relationship of the discharge circuit of the electric spark forming machine tool is that the power positive end is connected with the positive end of the diode D1, the negative end of the diode D1 is connected with one end of the resistor R1, the other end of the resistor R1 is connected with the drain D of the MOS tube Q1, the source S of the MOS tube Q1 is connected with the electrode end P2, the electrode end P2 and the workpiece end P3 are immersed in the working liquid to process the workpiece, the workpiece end P3 is connected with one end of the inductive device L1, the other end of the inductive device L1 is connected with one end of the resistor R2, and the other end of the resistor R2 is connected with the power negative end P4.

3. The circuit structure of the discharge absorption circuit of the electro discharge machine according to claim 2, wherein The inductive device L1 is connected with the relay K1 in parallel.

4. The circuit structure of the discharge absorption circuit of the electro discharge machine according to claim 2, wherein The MOS tube Q1 is turned on or turned off through pulse control.

5. The circuit structure of the discharge absorption circuit of the electro discharge machine according to claim 1, wherein The connection relationship of the first absorption circuit (100) is that the positive end of the diode D7 is connected with the power negative end P4, the negative end of the diode D7 is connected with one end of the resistor R4, and the other end of the resistor R4 is connected with the workpiece end P3.

6. The circuit structure of the discharge absorption circuit of the electro discharge machine according to claim 2, wherein The connection relationship of the second absorption circuit (200) is that the diode D1 negative end P1 is connected with one end of the resistor R5, the other end of the resistor R5 is connected with the negative end of the voltage stabilizing diode D3, the positive end of the voltage stabilizing diode D3 is connected with the negative end of the voltage stabilizing diode D4, the positive end of the voltage stabilizing diode D4 is connected with the negative end of the voltage stabilizing diode D5, the positive end of the voltage stabilizing diode D5 is connected with the positive end of the diode D6, and the negative end of the diode D6 is connected with the electrode end P2.

7. The circuit structure of the discharge absorption circuit of the electro discharge machine according to claim 6, wherein The voltage stabilizing diode D3 is connected with the relay K3 in parallel, and the voltage stabilizing diode D4 is connected with the relay K4 in parallel.

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