JPH0243620Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention relates to an electric discharge machining device, and in particular, the machining power supply unit is divided into two and distributed at intervals on both sides of the column of the electric discharge machine main body. By circulating cooling air into the machining power source section through the above-mentioned interval, the heat of the machining power source section, which generates heat, is averaged out.

Conventional technology Conventionally, a normal electrical discharge machine consists of three main sections: a machining power supply section, a machining fluid supply device, and a machining machine main body, and other control devices such as an NC device (numerical control device) are installed as necessary. In some cases, the processing machine itself is equipped with an automatic electrode exchange device AEC, etc., but these three main sections are
It is one.

For example, in an electric discharge machine called DP35BNC with the product name JATO2P, as shown in Fig. 5, a machining power supply unit 2 is installed on the right side of the electric discharge machine body 1, and a machining fluid supply device 3 is installed behind it. Main body 1
An NC device (numerical control device) 4 called JAPT-D2P (trade name) is installed on the left side of the machine as required, and in the case of DP35B, an AEC (electrode exchange device) is further installed on the electrical discharge machine main body 1. Here, the machining fluid supply device 3 selects mainly hydrocarbon-based insulating oils and fats such as kerosene and transformer oil, or water or an aqueous solution as the machining fluid, and supplies the machining fluid to the electrodes and workpiece belonging to the electrical discharge machine main body. , These are soaked in machining fluid or jetted to the discharge machining part to cool the discharge part, electrode, and workpiece, and to remove and flow out discharge debris generated from the machining gap. The power supply section includes a power supply device for generating pulses for electric discharge machining, and is made up of circuit elements for uniformizing the energy of a single discharge, elements for increasing the discharge repetition frequency, and safety devices, Stable machining conditions can be obtained only when the energy is uniform, and various circuits have been devised and included to prevent the transition to steady arc discharge even if the discharge repetition frequency is increased, but the power supply capacity 3KVA; about 4KVA, and the loss due to various resistances and inductances included in the energy release circuit of the capacitor is released as heat generation energy, the temperature rises and affects the surroundings, and sometimes some parts of the casing of the electrical discharge machine are heated. In some cases, one side may become unbalanced, such as by curving a support or the like that is located close to the power source.

Problems that the invention aims to solve As the speed of electric discharge machining increases, various measures have been taken to reduce the self-inductance value of the lead wire that connects the machining power source and the electrode. Summer. For example, one constructed of a large number of unit parallel conducting wires adjacent to a lead wire is used. However, in order to reduce this self-inductance value, it is important to shorten the length of the lead wire, and for this reason, it is desirable that the power supply section for processing be installed as close to the processing section as possible. Ta.

Means to Solve the Problems Taking these points into consideration, in this invention, the machining power supply unit is divided into two parts, placed on both sides of the column of the electrical discharge machine main body, and separated from the column. By fixing them at intervals, the amount of heat generated is dispersed, and the temperature rise on the electric discharge machine main body is suppressed, thereby eliminating the influence of heat generated by the machining power source on the electric discharge machine main body. Furthermore, the floor space can be reduced by dividing the processing power supply into two and attaching them to the main body.

Function By installing the machining power supply unit in the column close to the workpiece machining position in this way, the length of the lead wire connecting between the machining power supply unit and the electrode can be shortened. It was also possible to reduce the value of self-inductance.

The internal configuration of the machining power supply section divided into two parts can be made to have the same configuration, or one can be provided with a machining power supply device and the other a machining pulse generator, or a DC chipper etc. can be used. A plurality of unit power supply devices are prepared, and a predetermined number are selected and arranged from among them. Furthermore, this processing power supply device is provided with a cooling air flow path.
The cooling air that flows into this flow path flows through the gap between the column and the column.
The column is also cooled to prevent the effects of heat generated by the processing power source. Each of these two machining power supply devices is provided with a temperature detector, and the flow rate of the cooling air is controlled based on the detection signal from the temperature detector.

Embodiment Next, this invention will be explained based on the drawings illustrating the invention. 1 and 2 are side views schematically illustrating an embodiment of this invention. Reference numeral 1 denotes a main body of an electric discharge machine, and machining power supply units 5 and 5' are arranged on both sides of the main body with a gap d between them.
Figure 3 is a partially simplified diagram of the machining power supply section 5, 5', in which 12 and 12' are transformers, 13 and 13' are power transistors, and 15 is a low-power precision control section, which can be mounted on a chassis etc. as before. , housing 1
1.

Further, the power transistors 13, 13' and the transformers 12, 12' are heat pipes, 14a, 14, respectively.
The heat pipes 14a, 14b, 14c, and 14d are connected to one ends of the heat pipes 14a, 14c, and 14d in such a manner that high efficiency heat transfer is possible. Set it in

That is, a fan 16 is installed in a part of the cooling path 10 formed in a cylindrical shape or the like by the partition walls 6a and 6b inside the housing, and when the power is turned on and a flow of air is caused, the flow of the air causes the heat pipes 14a, 14b,
The other end is inserted into the cooling path 10 so that 14c and 14d are cooled. 7a, 7b, 7c, and 7d are fins provided at the other ends of the heat pipes 14a, 14b, 14c, and 14d, respectively. Next, 8a is provided at the entrance of the relatively rough filter cooling passage. 8
Reference numerals b, 8c and 8d are narrow-mesh filters, which are airtightly partitioned from the cooling path 10 by tubes or partition walls 6a and 6b to form a natural air flow for assisting the power transistor section and cooling the low-power control device. be.

The filter is made of glass fiber or fabric, and the natural cooling is performed at a relatively low temperature, even at a high temperature.
If used in areas where temperatures do not reach 200℃, it is effective in preventing dirt and dust from entering.

Further, 9 is a general-purpose switch provided at the outlet of the cooling path 10, which will not operate if the lid 11a is closed when not in use.
It is more convenient if the switch is turned on and the fan 16 is turned on when the lid 11a is opened.

In this way, the heat pipes 14a, 14
Using b, 14c, and 14d, all elements with a large amount of heat are connected by a heat pipe so that heat can be transferred, and the heat pipe is extended to a certain length, and fins are attached to the other ends as necessary.
The one end of the heat pipe is inserted into a cooling path 10 that is airtightly separated, and when a temperature detector (not shown) detects a predetermined temperature, a fan 16 is used to force air to flow through the cooling path 10. The elements themselves are partitioned and airtightly separated within the housing by partition walls 6a, 6b, etc. that form the cooling path 10, so that there is no problem even if they come into direct contact with the outside air, and the low power control device is connected via a filter 8c. This system prevents dirt and other particles from entering the tank, and allows cooling in natural flow. In addition, the cooling path 10 is usually 1 as shown in the figure.
One end of the heat pipe is provided at one place or at one place, and one end is connected to a control element, etc. to be cooled in each part of the housing 1, and the other end is all inserted into the cooling path 10, so that forced cooling is possible. This is efficient, easy to take measures against noise, and solves problems such as dust inhalation and accumulation.

FIG. 4 shows an example of the structure of the machining power supply section 5. As shown in FIG. Reference numerals 17 and 18 denote a processing electrode and a workpiece, which form a processing gap by opposing each other. 19
is a three-phase rectifier that directly rectifies the input commercial alternating current.
This output DC voltage is charged to a capacitor 20. Reference numeral 21 denotes a main transformer, in which the neutral point of the primary coil and both ends are connected in parallel to a capacitor 20, and thyristors 6 as on and off switches are connected in series to both ends.
1 and 62 are inserted to form a converter that converts the direct current of the capacitor 20 into an alternating current of a high frequency higher than the commercial alternating current frequency. The thyristors 61 and 62 are an oscillator 23 of a control circuit that operates in response to the discharge state of the machining gap.
Flip-flop 2 that oscillates synchronously with the high frequency of
4 is alternately triggered by the output of transformer 2.
1. Generate high frequency AC power. A rectifier 25 rectifies the high frequency power induced in the secondary coil of the transformer 21, and its output is connected to the machining gap through a smoothing circuit 26. Reference numeral 27 denotes a switch element such as a power transistor inserted in series with the power supply circuit, and is controlled on/off by an oscillator 28 such as a multivibrator. 29 is a changeover switch for connecting the power source to the machining gap with or without the switch 27.

If the machining gap is normal, the oscillator 23 oscillates at a high frequency higher than the commercial AC frequency, for example several hundred to several KHz, which activates the flip-flop circuit 24 and triggers both thyristors 61 and 62 alternately, turning them on and off. Repeat switching.

Therefore, the thyristors 61 and 62 are turned on,
By off-switching, the capacitor 20 discharges to the primary coil of the transformer 21, and the transformer 2
1 is the number 100 that the DC of capacitor 20 is converted to
A high frequency alternating current of approximately several kilohertz is supplied, this high frequency alternating current is transformed to a predetermined voltage and induced in the secondary coil, and this is rectified into direct current by a rectifier 25 and a smoothing circuit 26. Since the switch 27 is controlled on and off by the oscillator 28, a rectangular pulse is supplied to the machining gap and intermittent electric discharge machining can be performed.

In this way, if the machining gap is normal, the oscillator 23 oscillates normally, both thyristors 61 and 62 are turned on and off repeatedly, high frequency alternating current is supplied to the transformer 21, large power is supplied to the machining gap, and the speed is high. However, if gas discharge, arcing, etc. occur due to the influence of gas and machining debris generated during this machining, the voltage in the machining gap usually decreases, and the oscillator 23 detects this and changes the oscillation frequency. In response, the flip-flop circuit 24 is controlled to shorten the switching on pulses of the thyristors 61 and 62, and as a result, the transformer 21
The secondary side induced voltage of the DC power is rectified by the rectifier 25 and is controlled to be reduced, so that the machining pulse applied to the machining gap is sufficiently reduced in peak value to prevent abnormal discharge and to maintain normal operation. Automatic control is performed to ensure quick recovery.

In the machining power supply units 5 and 5' configured in this way, the commercial AC 19, the capacitor 20, the oscillator 23 which is a DC chopper, the flip-flop 24, and the thyristors 61 and 62 are connected to one of the machining power supply units 5 and 5'.
and a transformer 2 is installed in the other processing power supply section 5'.
1, rectifier 25, switch element 27, oscillator 28
It is also possible to house a part that generates pulses such as the following.

Effects of the invention The machining power supply units 5, 5' of this invention configured as described above not only disperse heat generation, but also maintain gaps d, d' with the electric discharge machine main body 1 to soften the temperature rise and reduce the temperature increase due to heat. Distortion can be prevented, and the cooling air sucked into the machining power supply units 5, 5' through the gaps d, d' can also cool the column of the main body 1 to prevent distortion due to heat, which is effective. It has the following. In addition, in Figures 1 and 2, the machining fluid supply device 3
is omitted because it is at the back of the figure.

[Brief explanation of the drawing]

Figures 1 and 2 are a schematic side view and perspective view of the device according to this invention, Figure 3 is a processing power supply section, Figure 4 is a diagram illustrating the circuit of the processing power supply section, and Figure 5 is a conventional one. 1 is a schematic layout diagram of a known electrical discharge machining device. In the figure, 1 is the main body of the electrical discharge machine, 5 and 5' are the machining power supply parts, d and d' are the gaps, and 10 is the cooling path.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In an electrical discharge machining device consisting of an electrical discharge machine main body, a machining fluid supply device, a machining power supply section, and a control section, a predetermined space is provided on both sides of a column of the electrical discharge machine main body. An electric discharge machining apparatus in which a machining power source unit that generates heat is divided into two parts with an interval of . (2) The electrical discharge machining apparatus according to claim 1, wherein the two divided machining power supply sections each have the same configuration. (3) Electric discharge machining according to claim 1 of the utility model registration claim, characterized in that one of the two divided power supply parts for machining is provided with a power supply device for machining, and the other is provided with a pulse generator for machining. Device. (4) The electrical discharge machining apparatus according to claim 1, wherein a predetermined number of unit power supplies such as DC choppers are disposed in each of the two divided machining power supply parts. (5) The electric discharge according to claim 1 of the utility model registration claim, characterized in that the cooling air flowing through the machining power source is controlled by a temperature detector provided in the machining power source. Processing equipment.