JPH0724976B2 - Nozzle device for wire cut electrical discharge machining - Google Patents

Description

The present invention relates to a wire-cut electric discharge machining apparatus having a nozzle having a gap holding means that enables machining in a non-contact state between a nozzle and a workpiece. Regarding the device.

(Prior Art) A wire-cut electric discharge machining device performs machining in a direction substantially perpendicular to the axial direction of the wire electrode while axially updating and feeding the wire electrode between a pair of positioning guides arranged at intervals. The workpiece is moved relative to one another, and the working fluid is normally delivered to both sides of the work piece from a pair of working fluid injection nozzles arranged coaxially with the wire electrode and facing each other to the work piece. A voltage pulse that is an intermittent voltage pulse or a discharge pulse is applied between the wire electrode and the workpiece while being jetted and supplied, and machining is performed by the generated discharge.

In such wire-cut electric discharge machining, conventionally, the machining is generally performed with the tip of the nozzle in contact with the workpiece, although it depends on the machining conditions. However, when machining is performed by bringing the nozzles into contact with each other, the nozzles are worn or deformed, which reduces the machining accuracy. Further, the present inventor has already proposed in Japanese Utility Model Laid-Open No. 58-117,319 that the discharge state such as the discharge rate is detected and the distance between the nozzle and the workpiece is controlled according to the discharge state. In this case as well, it is inevitable that the nozzle contacts the surface of the workpiece.

(Problems to be Solved by the Invention) In view of the above-mentioned drawbacks of the prior art, the present invention prevents the wear and damage of the nozzle caused by the contact of the nozzle with the workpiece, and prevents the deterioration of the machining accuracy caused by these. An object of the present invention is to provide a nozzle device for wire-cut electric discharge machining having a configuration that can be performed.

(Means for Solving the Problems) In order to achieve the above object, the nozzle device of the present invention provides a nozzle movably in the axial direction with the wire electrode, a cylinder, and the inside of the cylinder and the nozzle. And a means for communicating with the inside, and a hydraulic cylinder device for controlling the movement of the nozzle by the relative movement of the piston and the cylinder due to the pressure change of the working fluid in the nozzle is provided.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a nozzle to which the present invention is applied and a configuration example around the nozzle. Reference numeral 1 is a wire electrode, 2A and 2B are upper and lower arms to which guide rollers 3A and 3B of the wire electrode 1 are attached. Yes, these are attached to a column or the like of the apparatus body (not shown). 4A and 4B are supporting members mounted on the arms 2A and 2B so that the vertical position can be adjusted by a manual handle or motors 5A and 5B, and 10 is a current-carrying pin, which is mounted on the supporting member 4A and is wear-resistant and insulating. By contacting the wire electrode 1 displaced by the pressing pin 10 'of the wire electrode 1
It constitutes an upper energizing device for applying a voltage to.
Reference numeral 6 is an energizing roller as a lower energizing device which also serves as a lower guide roller, and 7 and 8 are hollow cylindrical nozzles. These nozzles 7 and 8 are vertically mounted on the supporting members 4A and 4B, respectively. By having the guide plates 11A and 11B slidably fitted along 9A and 9B, the wire electrodes 1 are attached so as to be movable in the axial direction. Guide holders 14 and 15 for wire guides 12 and 13 are coaxially fixed inside the nozzles 7 and 8, respectively.

The nozzles 7 and 8 are respectively provided with pressurizing supply hoses 16 and 17 of the working fluid, from which the working fluid is supplied into the nozzles 7 and 8 at a predetermined pressure and flow rate, and the internal wire guide 1
The nozzles 2 and 13 are cooled and jetted from the upper and lower nozzles 7 and 8 to the processing portion 19 (22 indicates a processing groove) of the workpiece 18 from above and below, respectively, and the upper and lower ends of the nozzles 7 and 8 are discharged. Opening 20,21
The wire electrode 1, the current-carrying pin 10 and the current-carrying roller 6 are cooled by being ejected from

The workpiece 18 is fixed to a machining table 23, which is controlled by an X-axis motor 24 and a Y-axis motor 25 on a plane perpendicular to the axis of the wire electrode 1 under the control of a numerical controller. It can move freely along the contour shape. The wire electrode 1 is pulled out from a storage reel provided in a column or the like of the apparatus main body (not shown) via a brake roller or the like, extends downward from the guide roller 3A portion, and the energizing roller 6 and the guide roller of the lower arm 2B.
It is adapted to be wound or collected via a winding roller (not shown) via 3B to a winding reel or a collecting container such as a column body. Then, an intermittent voltage pulse is applied between the workpiece 18 and the wire electrode 1 to perform electric discharge machining.

Therefore, in this embodiment, the nozzles 7 and 8 are provided with a small diameter portion 7 between the working fluid jetting portions 7A and 8A and the working fluid introducing portions 7B and 8B.
C and 8C are respectively provided, and the hydraulic cylinders 26A, 27A and 26B, 27B are configured so that the distance between the nozzles 7 and 8 with respect to the workpiece 18 is maintained at a predetermined distance. . The hydraulic cylinders 26A, 26B are fixed to the guide frames 9A, 9B, respectively, and the respective piston rods 28A, 28B are connected to the arms 29A, 29B attached to the nozzles 7, 8 by pins, and the pistons 30A, 30B are connected. The work piece side chambers on one side of the chambers respectively house the push springs 31A and 31B, the work piece side chambers contact the ejection portions 7A and 8A by the hoses 32A and 32B, and the non-workpiece side chambers each hose 33A. , 33B to connect to the working fluid introducing portions 7B, 8B. On the other hand, a plurality of hydraulic cylinders 27A and 27B are fixed to the ejection portions 7A and 8A, respectively, and the piston rods 34A and 34B of the hydraulic cylinders 27A and 27B are fixed to the workpiece 18 respectively.
Connected to ring-shaped brushes 35A, 35B that feed power to
A push spring 3 is provided on the workpiece side chamber on one side of each piston 36A, 36B.
7A and 37B are accommodated respectively, and the respective non-workpiece side chambers are connected to the work introduction portions 7B and 8B by hoses 38A and 38B, respectively.

Of the above hydraulic cylinders, the hydraulic cylinders 26A and 26B fixed to the guides 9A and 9B are connected to the pistons 30A and 30B with the hydraulic pressure of the jetting portions 7A and 8A (this is referred to as P _A ) and the working fluid introduction. Part 7
Pressure difference (P _B −P _A ) from the hydraulic pressure of B and 8B (this is P _B )
And the spring force of the springs 31A and 31B in the opposite direction act,
When the nozzles 7 and 8 are close to the workpiece 18, the hydraulic pressure of the jet parts 7A and 8A
Since P _A becomes higher, and the pressure difference (P _B −P _A ) becomes smaller, the nozzles 7 and 8 are moved in the direction away from the workpiece 18 by the spring force. 18
And are held at predetermined intervals. In addition, the nozzles 7 and 8 are moved to the workpiece 18 by the jetting pressure of the machining liquid from the tip end openings of the jetting portions 7A and 8A.
When the force acting in the direction away from the workpiece acts and the pressure difference (P _B −P _A ) becomes small, it is possible to move the nozzles 7 and 8 in the direction away from the workpiece 18 only by the action of this force. In some cases, the hydraulic pressure P _A , which is introduced into the hydraulic cylinders 26A, 26B,
The springs 31A and 31B are not always necessary because P _B can be introduced by adjusting and setting them as desired.

In addition, the hydraulic cylinders 27A and 2A fixed to the nozzles 7 and 8 respectively.
7B corresponds to the pistons 36A and 36B, respectively.
When the fluid pressure P _B of B, 8B acts and the nozzles 7, 8 approach the workpiece 18, the fluid pressure P _{B of the} machining fluid introduction parts 7B, 8B becomes high, which causes the nozzles 7, 8 to work. Since it is moved away from 18, the nozzles 7, 8 are the same as the hydraulic cylinders 26A, 26B.
And the work 18 are held at a predetermined interval.
Therefore, the hydraulic cylinder 2 fixed to the guide frames 9A and 9B
6A, 26B and the hydraulic cylinders 27A, 27B fixed to the nozzles 7, 8 may be provided, but by providing both, the action of maintaining the distance between the nozzles 7, 8 and the workpiece 18 Will be more certain. According to this embodiment, the workpiece 18 and the nozzles 7, 8
Since it is possible to maintain the interval between and the predetermined interval, even if there are undulations such as unevenness on the surface of the workpiece 18, the interval between the nozzle and the workpiece is a predetermined interval in accordance with this undulation change. The nozzle tip does not come into contact with or collide with the surface of the workpiece, and the tip of the nozzle is not worn or damaged.

(Effects of the Invention) As described above, according to the present invention, the distance between the nozzle being machined and the workpiece is maintained at a predetermined interval even if the surface of the workpiece has undulations such as irregularities. Therefore, it is possible to prevent wear and damage of the nozzle due to the nozzle coming into contact with and colliding with the work piece, which in turn makes it possible to perform good processing with the desired processing accuracy.

[Brief description of drawings]

FIG. 1 is a front sectional view showing an embodiment of the nozzle device of the present invention. 1 ... Wire electrode, 7,8 ... Nozzle, 7A, 8A ... Machining liquid jetting part, 7B, 8B ... Machining liquid introducing part, 9A, 9B ... Guide frame, 11A, 11B ... Guide plate, 18 ... Workpieces, 26A, 26B, 2
7A, 27B …… hydraulic cylinder, 30A, 30B, 36A, 36B …… Piston, 32A, 32B, 33A, 33B, 38A, 38B …… Hose, 37A, 37B ……
Spring,

Claims (2)

[Claims] 1. A wire of a nozzle provided on a supporting member, in which a workpiece is opposed to a wire electrode axially renewed and fed between a pair of positioning guides spaced apart from each other with a minute gap therebetween. The machining fluid is ejected from the machining fluid ejecting part provided coaxially with the electrode to the machining area where the wire electrode and the workpiece face each other, and an intermittent voltage pulse is applied between the wire electrode and the workpiece to repeat. In a nozzle device used for wire-cut electric discharge machining, in which a discharge is generated and a relative machining feed in a direction substantially perpendicular to the axial direction of the wire electrode is applied to a workpiece to perform machining of a desired contour shape, the nozzle is Provided so as to be movable in the axial direction of the wire electrode with respect to the support member, and to be connected to a cylinder or a piston of a hydraulic cylinder device which is formed by connecting one of the piston and the cylinder to the support member, The hydraulic cylinder device comprises means for connecting the cylinder chambers on both sides of the piston to a machining fluid jetting portion of the nozzle and a machining fluid introducing portion which communicates with the jetting portion so that a pressure difference can be formed therebetween. Nozzle device for wire cut electrical discharge machining. 2. A nozzle device for wire cut electrical discharge machining according to claim 1, wherein one of the pressing springs in the cylinder chamber is inserted.