JPS61260927A - Wire electric discharge machine - Google Patents

Abstract

PURPOSE:To buffer the shock on falling of a workpiece and stop a machining operation by supporting a lower jet nozzle with a spring and detecting the fall of said workpiece by means of a limit switch. CONSTITUTION:When a workpiece 12a has fallen on a lower jet nozzle 26b', the shock on falling of the workpiece 12 is buffered by a nozzle-breakage protection spring 46. Then, a stopping bar 42 is brought into contact with a limit switch 40 to detect the fall and stop a machining device. Also, when a work to be machined 12 is insufficiently mounted being fixed under a surface table, the workpiece is brought into contact with the jet nozzle as in the case of falling, compressing the protection spring and, then, the stopping bar is brought into contact with the limit switch, detecting failure in mounting. Thus, the damage of the jet nozzle, etc. can be prevented, enabling an unmanned and highly accurate machining to be carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wire electrical discharge machining apparatus equipped with a machining fluid spout protection mechanism.

[Conventional technology]

As shown in FIG. 2, the machining fluid spouting section of the conventional wire electrical discharge machining device has an upper spout nozzle 26 & that protrudes above and below the workpiece 12 to supply the machining fluid to the machining section of the workpiece. Machining fluid ejection mechanism 20 and lower ejection nozzle 26bt
- A protruding lower machining fluid ejecting mechanism 22 is disposed, and wire electrodes are supplied with discharge power from upper and lower power supply portions 34 and 36 connected to a power source 38, respectively, within the two machining fluid ejecting mechanisms. Upper and lower electrode guides 30.degree. 32 are fixedly installed, and the electrode guides 10 are slidably supported on the processing portion of the workpiece. Furthermore, although the lower machining fluid ejecting mechanism is fixed to the machine body (not shown), the position of the lower machining fluid ejecting mechanism in relation to the workpiece 12 is determined at the first position during stacking. The state is as shown in Figure 3a. However, at the end of the machining, the workpiece 12 falls from the workpiece and reaches the lower jet nozzle 2, as shown in FIG. 3b.
6b and applies an impact, which causes a problem of changing the support state of the lower machining liquid ejection mechanism, which causes trouble in wire electric discharge machining. To do this, 1. In order to protect the nozzle, a workpiece fall prevention jig (not shown) is installed to temporarily stop the machining process and fix the workpiece and the workpiece at the same time, and then Further processing is continuing.

[Problem that the invention seeks to solve]

However, since the fall prevention jig is installed by coming into contact with the workpiece during machining, it has a negative effect on machining accuracy, and the above-mentioned work by the worker before the end of one machining process is This reduces work efficiency and makes it impossible to achieve completely unmanned operation, and if the above-mentioned fall prevention work is not performed, the lower jet nozzle 26b' may be damaged due to the fall impact of the workpiece. Furthermore, the problem of changing the supporting state of the lower machining fluid ejecting mechanism occurs, and if the machining operation is continued until the workpiece falls into contact state 1, the lower machining fluid ejecting mechanism and other equipment will be damaged, making it impossible to continue the work. What's more, damage such as vertical streaks may occur on the workpiece, reducing the quality of the machined part, and in the worst case scenario, the workpiece will have to be discarded just before the end of machining. If the workpiece 12 is lowered from the mounting plate due to insufficient fixation, high-precision machining will not be possible, and the workpiece will interfere with the lower jet nozzle 26b, causing damage to the nozzle, etc. There are various problems such as giving.

The present invention prevents the machining fluid jet nozzle from being damaged even without installing a workpiece fall prevention jig during wire electric discharge machining work, and does not cause a decrease in machining work efficiency.
It is an object of the present invention to provide a wire electrical discharge machining device capable of realizing stable, high-precision machining by detecting attachment failure of a workpiece.

[Means for solving problems]

This invention has a lower machining fluid ejection mechanism in which a nozzle sliding cylinder is fixedly fixed inside and protrudes around a companion lower electrode guide, and a lower jetting nozzle is fitted into the sliding cylinder so as to be slidable up and down. An IJ that presses the jet nozzle upward by a nozzle breakage protection spring inserted between the bottom of the jet nozzle and the sliding tube, and operates at a desired position of the jet nozzle.
A Mitsutswitch is fixed to the lower machining fluid ejection mechanism.

[Effect]

Therefore, according to the structure of the present invention, even if a falling workpiece contacts and presses the lower jet nozzle due to the buffering action of the nozzle damage protection spring, there is no risk of damaging the jet nozzle, and the desired state of the jet nozzle can be maintained. If the upper and lower positions of the electric discharge machining device are set so that the operation of the electric discharge machining device is stopped when the limit switch is detected, the machining device will stop when the falling workpiece presses the jet nozzle to the set position. This prevents machining from continuing with the fallen workpiece still in contact and causing problems.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings.
In FIG. 1, an upper machining fluid jetting mechanism 20 having an upper jetting nozzle 26a protruding from above the workpiece 12 for supplying machining fluid to the machining portion thereof is disposed, and a power source 68 is connected to the jetting mechanism. An upper electrode guide 30 is fixedly installed in which a wire electrode 10 that supplies discharge power from the upper power supply part 34 is slidably supported on the processing part of the workpiece. Further, below the workpiece, there is a lower part in which a wire electrode 10, which is supplied with discharge power from a lower power supply part 36 connected to the power supply, is slidably supported on the processing part of the workpiece. In addition to fixing the electrode guide 62, a lower machining liquid ejection mechanism 22' fixed to the machine body (not shown) is provided, and a nozzle sliding cylinder 50 is protruded around the lower electrode guide of the ejection mechanism. The lower jet nozzle 26'b' for supplying machining liquid to the processing section of the workpiece is fitted into the sliding tube so as to be able to slide up and down, and between the bottom of the jet nozzle and the outer bottom of the sliding tube. A nozzle damage protection spring 46 is inserted to press the jet nozzle upward.

Further, a nozzle stop tube 44 is protruded from the lower jetting mechanism 22' around the sliding tube, and the top of the stop tube is brought into engagement with the side of the jet nozzle, thereby preventing the nozzle from escaping. furthermore, the stop actuation rod 42 is removed from the bottom of the nozzle.
is vertically disposed so that the end of its actuating rod contacts a limit switch 40 fixedly attached to the lower ejection mechanism 22' at a desired vertical position of the ejection nozzle. In addition, the nozzle sliding tube 50
An O-ring 48 is embedded in the sliding surface of the ejection nozzle 26'b to maintain a seal so that the machining liquid ejected into the ejection nozzle does not enter the nozzle stop tube.

Therefore, when the workpiece 12a falls onto the lower jet nozzle 26'b according to the present invention, the impact of the workpiece fall is buffered by the nozzle breakage protection spring 46, and then the stop actuating rod 42 is moved to the limit position. detecting the fall of the workpiece by touching the switch 40 and stopping the processing device;
Even if the workpiece 12 is insufficiently installed and fixed under the surface plate, the workpiece comes into contact with the jet nozzle and compresses the protective spring in the same manner as when the workpiece falls, and then the Incorrect installation is detected by the stop actuating rod coming into contact with the limit switch. In addition, in the above-mentioned embodiment, the fall of the workpiece is detected using an IJ switch, but the same effect can be obtained by using a piezoelectric element, a proximity switch, a short-circuit detection mechanism, etc. in place of the switch. There is no need to go into detail about what you can do.

〔Effect of the invention〕

As described above, in this invention, the lower jet nozzle is supported by a spring to buffer the impact of the workpiece falling, and the fall of the workpiece is detected by the IJ Mitswitch and the machining operation is stopped. In addition to eliminating the need to temporarily suspend the work to prevent the workpiece from falling, even if the workpiece is not properly attached to the surface plate and is fixed under the surface plate, the installation detects the installation failure and prevents damage to the jet nozzle, etc. This has the effect of allowing highly accurate machining to be performed unattended.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional side view of the main part showing an embodiment of the present invention;
Fig. 2 is a vertical side view of the main parts of a conventional wire electric discharge machining device, Fig. 6a is a longitudinal side view showing the relative position between the lower machining fluid ejection mechanism and the workpiece during standard machining, and Fig. 3b The figure is a longitudinal sectional side view showing the relationship at between the lower machining liquid ejection mechanism and the workpiece when the workpiece falls. 10... Wire electrode, 12... Workpiece, 12a.
... Workpiece, 20... Upper processing liquid ejection mechanism, 22...
・Conventional lower machining liquid ejection mechanism, 22'...Lower machining liquid ejection mechanism according to the present invention, 26b...Conventional lower ejection nozzle, 26'b...Lower ejection nozzle according to the present invention, 4
0...Limit switch, 42...Stop operating rod, 4
4... Nozzle stop tube, 46... Nozzle damage protection spring, 50... Nozzle sliding tube. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent: Patent Attorney Tadashi Sato Year 1, Figure 2, Figure 3a, Figure 3b

Claims (1)

[Claims] A lower jet nozzle is fitted into the sliding cylinder of a lower machining liquid jetting mechanism in which a nozzle sliding cylinder is protruded around a lower electrode guide fixedly installed inside the lower working fluid jetting mechanism, and the lower jetting nozzle is slidably moved up and down. and a nozzle breakage protection spring inserted between both bottoms of the sliding tube to press the jet nozzle upward, and a limit switch that operates at a desired position of the jet nozzle is fixed to the lower machining fluid jet mechanism. A wire electrical discharge machining device characterized by: