JP2000210818A - Wire electric discharge machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wire electric discharge machine with simple structure and a small processing tank. SOLUTION: The height of a liquid level is calculated from a slider position detected by a position detection sensor when a liquid level detection sensor detects the liquid level. The exhaust time to drain processing liquid through an exhaust valve until liquid level height for wire connection is reached in accordance with the liquid level height, is calculated (S210). The exhaust valve is opened in accordance with the calculated exhaust time (S220-S240), and the processing liquid in a processing tank is drained until the liquid level height for wire connection is reached.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire electric discharge machine for machining a workpiece by applying a predetermined voltage between a wire electrode and the workpiece.

[0002]

2. Description of the Related Art Conventionally, in a wire electric discharge machine, a workpiece is immersed in a machining fluid in a processing tank to process the workpiece. During processing, the processing liquid is ejected from the upper and lower nozzles into the processing tank, and the processing liquid is discharged from the outlet of the processing tank. At this time, a liquid level detection sensor 102 is provided in the processing tank 100 as shown in FIG. 8 so that the liquid level of the processing liquid is constant.
The opening and closing of a discharge valve 106 provided at a discharge port 104 of the processing tank 100 is controlled.

[0003] Further, when performing a wire connection operation for processing another part of the workpiece or replacing the workpiece with a new one, the processing fluid in the processing tank 100 is discharged and the liquid level is temporarily reduced. The height is reduced. For example, when the machining fluid is discharged so as to have a liquid level for performing the connection work (a two-dot chain line in FIG. 8), as shown in FIG. A detection sensor 108 is provided, and when the liquid level is detected by the liquid level detection sensor 108, the discharge valve 106 is closed.

[0004]

However, in such a conventional apparatus, a plurality of liquid level detection sensors 102 and 108 must be provided in order to detect the liquid level, which makes the apparatus complicated and requires a processing tank. There was a problem that it became large and expensive.

An object of the present invention is to provide a wire electric discharge machine having a simple apparatus and a small machining tank.

[0006]

In order to achieve the above object, the present invention takes the following means to solve the problem. That is, an upper nozzle through which a supplied wire electrode passes, and a lower nozzle through which the workpiece is disposed and opposed to the upper nozzle, and a lower nozzle through which the wire electrode passes, and a slider supporting the upper nozzle are vertically moved. A moving mechanism for moving, a position detecting means for detecting the position of the slider, a processing tank provided with a drain port for immersing the workpiece in a processing liquid, and a discharge provided in the drain port for opening and closing the drain port A valve, a liquid level detecting means provided on the slider for detecting a liquid level of the processing tank,
In a wire electric discharge machine that relatively moves the wire electrode and the workpiece and generates a pulse discharge between the two to perform machining, when a liquid level is detected by the liquid level detection unit. Calculating the liquid level from the slider position detected by the position detecting means, and calculating the discharge time for discharging the machining liquid through the discharge valve until the connection liquid level is reached according to the liquid level. A wire electric discharge machine, comprising: a calculating unit that performs the discharging operation; and a control unit that opens the discharge valve in accordance with the discharge time calculated by the calculating unit.

In addition, an upper nozzle through which a supplied wire electrode passes, a lower nozzle through which the wire electrode passes, and a slider which supports the upper nozzle and is located between the workpiece and the upper nozzle. A moving mechanism for moving the slider in the vertical direction, position detecting means for detecting the position of the slider, a processing tank provided with a drain port and immersing the workpiece in a processing liquid, and a drain port provided in the drain port. A discharge valve for opening and closing, and a liquid level detecting means provided on the slider for detecting a liquid level in the processing tank, wherein the wire electrode and the workpiece are relatively moved, and a pulse discharge is generated between the two. In a wire electric discharge machine that performs machining by generating a, the liquid level is calculated from the slider position detected by the position detecting means when the liquid level is detected by the liquid level detecting means,
Calculating means for calculating a discharge time for discharging the processing liquid through the discharge valve until the opening / closing liquid level of the processing tank is reached in accordance with the liquid level; and the discharge time calculated by the calculating means Control means for opening the discharge valve in accordance with
This is a wire electric discharge machine characterized by having:

[0008] Further, an upper nozzle through which a supplied wire electrode passes, a lower nozzle through which the wire electrode passes, and a slider which supports the upper nozzle and is located between the workpiece and the upper nozzle. A moving mechanism for moving the slider in the vertical direction, position detecting means for detecting the position of the slider, a processing tank provided with a drain port and immersing the workpiece in a processing liquid, and a drain port provided in the drain port. A discharge valve for opening and closing, and a liquid level detecting means provided on the slider for detecting a liquid level in the processing tank, wherein the wire electrode and the workpiece are relatively moved, and a pulse discharge is generated between the two. In a wire electric discharge machine that performs machining by generating a, the liquid level is calculated from the slider position detected by the position detecting means when the liquid level is detected by the liquid level detecting means,
Calculating means for calculating a discharge time for discharging the working fluid through the discharge valve until the liquid level reaches a liquid level which is selectively instructed in advance in accordance with the liquid level; and the discharge calculated by the calculating means. And a control means for opening the discharge valve in accordance with time.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. As shown in FIG. 1, reference numeral 1 denotes a wire electric discharge machine, in which a column 4 is attached to a base 2. A control box 6 having a control circuit 70 and a processing power supply which will be described later is mounted on the column 4.

The column 4 is provided with a moving mechanism 10 for moving the slider 8 in a vertical direction. Further, a wire supply mechanism 12 is provided at an upper portion of the column 4, and supplies the wire electrode 16 fed from a wire supply reel 14 rotatably supported to a pair of brake rollers 18 and 20. I do.

The wire electrode 16 pulled out from the brake rollers 18 and 20 is further guided by a guide roller 22 and guided to an upper wire guide portion 24 attached to the lower end of the slider 8. An upper nozzle 26 is provided at the lower end of the upper wire guide 24, and the upper wire guide 2
The wire electrode 16 guided by 4 is drawn downward through the upper nozzle 26.

A processing tank 34 is mounted on the base 2, and the workpiece 28 mounted and fixed on a mounting table 36 provided in the processing tank 34 is provided with an insulating processing liquid (fresh water or fresh water). And a mixture of oil and oil 38). The processing liquid 38 is supplied from a processing liquid supply device (not shown), and the processing liquid 38 contaminated by the processing is collected by the processing liquid supply device, filtered through a filter or the like, and then circulated again to be supplied. In addition, the mounting base 36 is configured to move the workpiece 28 on an XY plane orthogonal to the axial direction (Z axis) of the slider 8.

The lower arm 40 is inserted into the processing tank 34 from the column 4.
Are pulled out, and the lower wire guide portion 32 is placed on the tip of the lower arm 40. A lower nozzle 30 is arranged facing the upper nozzle 26 with the workpiece 28 therebetween, and the lower nozzle 30 is provided on the lower wire guide portion 32. Wire electrode 16 passing through lower nozzle 30
Are guided by the lower wire guide portion 32, and are guided by a guide roller 42 provided on the lower arm 40 along a pair of guide rollers 44 and 46 provided on the column 4 along the lower arm 40.
Has been guided to.

The wire electrode 16 pulled out from the guide rollers 44 and 46 is guided to a wire cutting mechanism 48, and the wire electrode 16 is pulled by a driving roller provided in the wire cutting mechanism 48. Further, the wire electrode 16 guided into the wire cutting mechanism 48 is continuously and finely cut by a rotating blade (not shown), and is collected as a wire cut piece 50 in the collection container 52.

On the other hand, a power supply (not shown)
A pulse current is applied to the workpiece 28 and the workpiece 28, and electrical discharge machining is performed at a minute gap (electric discharge machining portion) between the wire electrode 16 and the workpiece 28 that pass vertically downward. In addition, the machining fluid 38 is ejected toward the electric discharge machining portion from both or any one of the upper nozzle 26 and the lower nozzle 30 to remove metal scraps in the electric discharge machining and cool the electric discharge machining portion. The wire electrode 16 usually has a diameter of 0.05 mm to 0.5 mm.
It is as thin as about 3 mm. The transport speed (moving speed) of the wire electrode 16 depends on the electric discharge machining conditions and the workpiece 28.
There are various types depending on the plate thickness, etc.
３００300 mm / sec.

As shown in FIG. 2, a discharge port 54 is formed below the processing tank 34, and the discharge port 54 has a discharge port 5 formed therein.
An opening / closing door 56 for opening / closing the door 4 is provided. Door 56
Is configured to be moved by an actuator 58 using a cylinder. In the present embodiment, the opening and closing door 5
6. The discharge valve 60 is constituted by the actuator 58.

The moving mechanism 10 is provided with a position detecting sensor 62 for detecting the position of the slider 8 in the vertical direction. The slider 8 is provided with a liquid level detection sensor 64 using a float switch for detecting the liquid level of the processing liquid 38 in the processing tank 34. The position detection sensor 62 and the liquid level detection sensor 64 are connected to a control circuit 70. The control circuit 70 includes a well-known CPU 72, a ROM 74, and a RAM 7.
6 as a logical operation circuit.
An input / output circuit 78 for performing input / output with the mounting base 36, the actuator 36, the position detection sensor 62, the liquid level detection sensor 64, and the like is mutually connected via a common bus 80.

The CPU 72 inputs data from the position detection sensor 62 and the liquid level detection sensor 64 via an input / output circuit 78, and based on data in the ROM 74 and the RAM 76 and a control program stored in advance, the CPU 72 inputs the data. A signal is output to the moving mechanism 10, the mount 36, the actuator 58, and the like via the output circuit 78.

As shown in FIG. 4, when the actuator 58 is driven to open the opening / closing door 56 and discharge the processing fluid 38 from the discharge port 54, as shown in FIG. Are stored. This may be obtained in advance by an experiment or the like.

Next, the discharge control process performed in the control circuit 70 will be described with reference to the flowchart of FIG. In this discharge control processing, when the processing of the workpiece 28 is completed, or when another location of the workpiece 28 is processed, the workpiece 28 is replaced with a new workpiece 28 or another location is processed. This is executed when a connection work is performed to perform the connection.

First, processing for stopping the processing and stopping the supply of the processing liquid is executed (Step 200; hereinafter, referred to as S200; the same applies hereinafter). Next, a discharge time for opening the discharge valve 60 to discharge the working fluid 38 is calculated (S210). The calculation of the discharge time is performed based on the graph shown in FIG.

The liquid level height Z1 of the processing liquid 38 in the processing tank 34 when the processing is stopped is detected by the liquid level detection sensor 64 and the position detection sensor 62. That is, the liquid level detection sensor 6
When the liquid level of the processing liquid 38 is detected by the position detection unit 4, the position of the slider 8 is detected by the position detection sensor 62,
That position corresponds to the liquid level height Z1. This liquid level height Z1
The discharge time T1 is obtained from the graph of FIG. The discharge time T1 indicates a time required until the processing liquid 38 having the liquid level Z1 is completely discharged from the processing tank 34.

Then, the working fluid 38 is discharged and, for example,
In the case of discharging until the liquid level H2 at the time of the connection work is reached, the discharge time T2 corresponding to the liquid level Z2 is obtained from the graph of FIG. Next, the required discharge time T (= T1 -T2) is calculated from the difference between the two discharge times T1 and T2.

After calculating the discharge time T, a drive signal is output to the actuator 58 to move the door 56 to open the discharge valve 60 (S220). Next, it is determined whether or not the discharge time T has elapsed (S230), and the discharge valve 60 is kept open until the discharge time T has elapsed. Thereby, the processing liquid 38 is discharged from the discharge port 54, and the liquid level is lowered.

The processing liquid 38 is discharged from the discharge port 54 in an amount corresponding to the liquid level, and when it is determined that the discharge time T has elapsed by executing the processing of S230, the actuator 5
8, the door 56 is moved, and the discharge valve 60 is closed (S240). When the discharge port 54 is closed, the liquid level of the working liquid 38 is equal to the liquid level Z2 during the connection work.

Next, a drainage work completion signal is output to open, for example, an automatic door (not shown) of the processing tank 34, or to turn on a work completion lamp or the like (S250).
The execution of the processing in S210 functions as a calculating means, and the processing in S2
Execution of the processing of 20 to S240 functions as a control unit.

With this arrangement, it is not necessary to previously provide a liquid level detecting sensor for discharging the processing liquid 38 until the liquid level reaches the liquid level height Z2 during the connection work. 34 is downsized. Also, the liquid level height Z
2 can be easily changed in accordance with the shape of the workpiece 28.

In the above-described embodiment, the case where the liquid level is discharged so as to be equal to the liquid level Z2 at the time of the connection work is described as an example. However, the present invention is not limited to this. When the workpiece 28 is replaced, the discharge time T (= T1 -T3) is calculated by executing the process of S210 so that the liquid level height Z3 required for opening and closing the door of the processing tank 34 is obtained. It may be. Alternatively, the calculation of the discharge time according to the two liquid level heights Z2 and Z3 may be selectively switched by operating a changeover switch provided on an operation panel (not shown).

Next, a second embodiment different from the above-described embodiment will be described with reference to FIG. Note that the same members as those in the above-described embodiment are denoted by the same reference numerals, and detailed description is omitted. The same applies hereinafter. In the second embodiment, the position of the discharge port 54 of the above-described embodiment is different, and the position of the discharge port 54a is formed according to the liquid level Z2 at the time of the connection work.
When moving the processing location of the workpiece 28 to another location, the processing liquid 38 is discharged and the wire electrode 16 is cut. Then, it moves to the hole position of the next processing location, and the processing liquid 3
After the elapse of the discharging time T2 in FIG. 8, the operation can be shifted to the automatic connection operation.

Further, as in a third embodiment shown in FIG.
The discharge port 54b may be provided at a position corresponding to the opening height of the automatic door 68 of the processing tank 34. After completing the processing of the first workpiece 28, the processing liquid 38 is discharged and the wire electrode 16 is cut. Then, the workpiece 28 is moved to a predetermined place, and after the discharge time T has elapsed, the automatic door 6 is moved.
8 may be opened and the next workpiece 28 may be attached.

As described above, the present invention is not limited to such embodiments at all, and can be implemented in various modes without departing from the gist of the present invention.

[0032]

As described in detail above, the wire electric discharge machine according to the present invention needs to be provided with a liquid level detecting sensor for discharging the machining liquid until the liquid level at the time of the connection work is reached. In addition, the apparatus is simplified and the processing tank is reduced in size. In addition, the same applies to the case where the liquid level is set according to the door of the processing tank instead of the liquid level during the forming operation. Furthermore, the liquid level can be easily adjusted to various liquid levels by selectively instructing the liquid level at the time of connection work, the liquid level in accordance with the door of the processing tank, and the like.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a wire electric discharge machine as one embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a processing tank of the present embodiment.

FIG. 3 is a block diagram illustrating a schematic configuration of a control circuit according to the present embodiment.

FIG. 4 is a graph showing a relationship between a liquid level and a discharge time according to the embodiment.

FIG. 5 is a flowchart illustrating an example of an output control process performed in the control circuit according to the embodiment.

FIG. 6 is a schematic configuration diagram of a processing tank according to a second embodiment.

FIG. 7 is a schematic configuration diagram of a processing tank according to a third embodiment.

FIG. 8 is a schematic configuration diagram of a processing tank of a conventional wire electric discharge machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Wire electric discharge machine 2 ... Base 4 ... Column 8 ... Slider 10 ... Moving mechanism 12 ... Wire supply mechanism 16 ... Wire electrode 24 ... Upper wire guide part 26 ... Upper nozzle 28 ... Workpiece 30 ... Lower nozzle 32 ... Lower wire guide part 34, 100 processing tank 36 mounting base 38 processing liquid 40 lower arm 54, 54a, 54b, 104 discharge port 56 opening / closing door 58 actuator 60, 106 discharge valve 62 position detection sensor 64, 102, 108: Liquid level detection sensor 68: Automatic door 70: Control circuit

Claims (3)

[Claims] 1. An upper nozzle through which a supplied wire electrode passes, and an upper nozzle disposed between the workpiece and the upper nozzle,
A lower nozzle through which the wire electrode passes; a moving mechanism for vertically moving a slider supporting the upper nozzle; position detecting means for detecting a position of the slider; A processing tank immersed therein, a discharge valve provided at the drain port for opening and closing the drain port, and a liquid level detecting means provided on the slider and detecting a liquid level of the processing tank, In a wire electric discharge machine that relatively moves the workpiece and generates a pulse discharge between the two to perform machining, the position is detected by the position detecting unit when the liquid level is detected by the liquid level detecting unit. Calculating a liquid level from the slider position to be calculated, and calculating a discharge time for discharging the working fluid through the discharge valve until the connection liquid level is reached according to the liquid level; By means Wire electric discharge machine, characterized in that and a control means for opening the exhaust valve depending on the calculated discharge time. 2. An upper nozzle through which a supplied wire electrode passes, and an upper nozzle interposed between the workpiece and facing the upper nozzle,
A lower nozzle through which the wire electrode passes; a moving mechanism for vertically moving a slider supporting the upper nozzle; position detecting means for detecting a position of the slider; A processing tank immersed therein, a discharge valve provided at the drain port for opening and closing the drain port, and a liquid level detecting means provided on the slider and detecting a liquid level of the processing tank, In a wire electric discharge machine that relatively moves the workpiece and generates a pulse discharge between the two to perform machining, the position is detected by the position detecting unit when the liquid level is detected by the liquid level detecting unit. The liquid level height is calculated from the slider position to be calculated, and the discharge time for discharging the processing liquid through the discharge valve until the liquid level reaches the liquid level of the door opening and closing of the processing tank according to the liquid level is calculated. Means and before Wire electric discharge machine, characterized in that and a control means for opening the exhaust valve in accordance with the discharge time calculated by the calculation means. 3. An upper nozzle through which a supplied wire electrode passes, and an upper nozzle arranged between the workpiece and the upper nozzle,
A lower nozzle through which the wire electrode passes; a moving mechanism for vertically moving a slider supporting the upper nozzle; position detecting means for detecting a position of the slider; A processing tank immersed therein, a discharge valve provided at the drain port for opening and closing the drain port, and a liquid level detecting means provided on the slider and detecting a liquid level of the processing tank, In a wire electric discharge machine that relatively moves the workpiece and generates a pulse discharge between the two to perform machining, the position is detected by the position detecting unit when the liquid level is detected by the liquid level detecting unit. The liquid level is calculated from the slider position to be calculated, and the discharge time for discharging the working fluid through the discharge valve until the liquid level reaches a liquid level which is selectively designated in advance according to the liquid level is calculated. Calculating means; Control means for opening the discharge valve in accordance with the discharge time calculated by the calculation means.