JPH0565291B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electric discharge machining apparatus in which a detector and a cleaning nozzle are attached to a machining head by attachment means different from the electrode attachment means. .

[Conventional technology]

Electrical discharge machining is commonly used as one of precision machining methods. Electrical discharge machining uses a tool as an electrode to generate an arc discharge between the workpiece and the workpiece, which removes a small amount of the surface of the workpiece and processes the workpiece into a shape that corresponds to the shape of the tool. It is something to do.

According to electrical discharge machining, it is possible to machine tough materials and highly hard materials that are difficult to machine into accurate shapes, and the surface can also be made relatively fine.Furthermore, as long as electrodes are made, it is possible to machine any shape. Since surfaces can also be machined, electric discharge machining is used, for example, to manufacture molds for press working.

In the case of such an electric discharge machining apparatus, the electrode is worn out little by little as machining progresses, so the feed amount of the electrode and the dimensions of the machined part formed on the workpiece do not necessarily match. For this reason, in the past, in order to perform high-precision machining using electric discharge machining, the shape of the machined part was measured once the machining had progressed to a certain extent, the next feed amount was determined from that value, and the machining was repeated. was. In other words, in electrical discharge machining equipment that is automatically operated by an automatic control device such as a computer or numerical control device (NC device, etc.), a detector is attached to the electrode attachment part instead of the electrode, and the detector is used to measure the workpiece. The dimensions of the machined part can be determined from the amount of movement of the machine at that time, or as shown in FIG. A detection holding part 109 is provided and a detector 108 is attached so as to be parallel to the electrode 104, and the dimensions of the processed part are determined by the detector.

[Problem that the invention is trying to solve]

In conventional electric discharge machining equipment, machining fluid is injected into the measuring part to remove dust and machining waste from the measuring part, but because the nozzle that injects the machining fluid is fixedly placed on the machining table, etc. Another problem was that if the measuring parts were to be measured at multiple points, it could not be cleaned sufficiently and dirt and processing waste could get in there, causing measurement errors.

[Means to solve the problem]

As a means to solve the above problems, the present invention includes:
A machining head holding an electrode for electric discharge machining a machining portion of a workpiece, a machining tank for immersing the workpiece in a machining fluid, and a machining tank that advances and retreats from the machining portion independently of the electrode to measure the machining portion. a detector, a means for supplying and recovering the machining fluid in the machining tank, a nozzle that injects fluid or gas to the machining section and/or the detector, and a suction that sucks the machining fluid and foreign matter accumulated in the machining section. An electric discharge machining apparatus is proposed, which includes a suction device having a member, and a drive device that drives the suction member of the suction device to the processing portion of the workpiece relative to the detector.

〔Example〕

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram of an electrical discharge machining apparatus according to the present invention, with the left-right direction being the X-axis, the front-rear direction being the Y-axis, and the up-down direction being the Z-axis. In the figure, reference numeral 1 denotes a machining head, which is movable in the Z-axis direction by a drive device (not shown), and the amount of movement thereof is measured by a position detection device (not shown). Reference numeral 2 denotes an electrode holder attachment part provided on the lower surface of the processing head 1, 3 an electrode holder attached to the electrode holder attachment part 2, and 4 an electrode attached to the electrode holder 3. 5 is a processing table which, like the processing head 1, can be driven in the Z-axis direction. 6 is the workpiece placed on the processing table 5, 6a is the processed part applied by the electrode 4, and 6b is the workpiece 6.
6c is the bottom surface of the processed portion 6a. 7 is a processing tank. Reference numeral 8 denotes a detector, which moves forward and backward in the Z-axis direction by operating a pneumatic cylinder, which will be described later. However, when the detector 8 is at the advancing end, that is, the descending end, the detector 8 is located relatively below the electrode 4, and when the detector 8 is at the retreating end, that is, the ascending end, the detector 8 is located relatively below the electrode 4. is also located above. Figure 1
indicates that the probe is at the rising end. 9 is a spherical measuring sphere located at the tip of the detector 8;
3 is a column, and 14 is an automatic electrode exchange device (AEC device). Further, 3a and 4a are replacement electrode holders and electrodes. 21 and 22 are support arms, 2
3 is a pneumatic cylinder attached to the processing head 1 by support arms 21 and 22; 24 is a piston rod engaged with the pneumatic cylinder 23; and 25
26 is a connecting member that connects the piston rod 24 and the rod 25; 27 and 28 are guide members that guide the vertical movement of the rod 26; 29 and 30 is a clamp device that clamps the rod-shaped body 25 when the cylinder 23 is stopped. 31 is a plate attached to the lower end of the rod-shaped body, 32 is a contact detection device attached to the plate 31, and the detector 8 is attached to the lower part. 33 is a machining fluid supply device that filters the machining fluid collected from the machining tank 7 and supplies it to the machining tank 7. 34 and 35 are machining fluid supply devices 33
With the machining fluid supply pipe extending further, 36, 37
is a nozzle attached to the opposite end of the machining fluid supply pipes 34 and 35 from the machining fluid supply device 33, and is arranged so as to spray the clean machining fluid sent from the machining fluid supply device 33 toward the measuring ball 9. has been done. 38
A nozzle 39 that supplies the machining fluid from the machining fluid supply device 33 to the machining tank 7 is a nozzle that collects the machining fluid from the machining fluid supply device 33.

FIG. 2 is a block diagram of the control system of the apparatus shown in FIG. In the figure, reference numeral 51 denotes an automatic control device, which is composed of a computer numerical control device (CNC device) 52 and a power supply control device (EC device) 53. Reference numeral 54 represents an X drive device that moves the processing table 5 in the X direction, and 55 represents an X position detection device that detects the position of the processing table 5 in the X direction. 56 is a Y drive device that moves the processing table 5 in the Y direction, and 57 is a Y detection device that detects the position of the processing table 5 in the Y direction. 58 is a Z drive device for moving the processing head 1 in the Z direction, and 59 is a Z position detection device for detecting the position of the processing head 1 in the Z direction. A pneumatic drive device 60 operates the air cylinder 23 and the clamp devices 29 and 30 in response to a command from the EC device 53. Reference numeral 61 denotes an AEC drive device which operates according to a command from the EC device 53. 62 is the discharge circuit and EC
An electric discharge is generated between the electrode 4 and the workpiece 6 according to a command from the device.

The CNC device 52 sends commands to operate the following X, Y, and Z drive devices, and also stores the values detected and sensed by the X, Y, and Z detection devices and the contact detection device 32. The EC device 53 controls the power supplies of the pneumatic drive device, AEC drive device, discharge circuit, and machining fluid supply device 33 described below. Also, the completion signal of each control is sent to the CNC device.

Hereinafter, the operation of the above configuration will be explained based on FIG. 1.

First, machining fluid is supplied to the machining tank 7 through the pipe 38 from the machining fluid supply device 33 in response to a command from the CNC device 52 . Next, the processing table 5 is moved in the XY axis directions by operating the X drive device 54 and the Y drive device 56 in response to a command from the CNC device 52, and the electrode 4 is positioned above the part of the workpiece 6 to be machined. . Next, by operating the Z drive device 58 in response to a command from the CNC device 52, the machining head 1 is lowered, stopped at a position where the distance between the electrode 4 and the workpiece 6 becomes minute, and discharge starts. . However, while the measuring ball 9 is moving, the workpiece 6
When it comes into contact with, a signal from the contact detector 32 is activated.
It is sent to the CNC device 52 and movement is stopped. Further, the positions of the machining head 1 and the machining table 5 at this time are detected by the X, Y, and Z detectors 55, 57, and 59, and are stored in the CNC device 52. Thereafter, the electrode 4 is moved downward little by little, the discharge is stopped at a predetermined position, and the machining head 1 is moved upward. As a result, a processed portion 10 corresponding to the shape of the lower and side surfaces of the electrode 4 is formed on the workpiece 6. After that, processing tank 7
The machining fluid inside is recovered to the machining fluid supply device 33 via the discharge pipe 39.

Next, the pneumatic drive device 60 causes the clamping device 2 to
The clamps 9 and 30 are released, the air cylinder 23 is operated to move the detector 8 to the lower end, and the clamp devices 29 and 30 are again operated and clamped. Next, the processing head 1 and the processing table 5 are moved to bring the measuring ball 9 closer to the upper surface 66 of the workpiece 6. At this time, the machining liquid is injected from the nozzles 36 and 37 to eliminate dust on the surface of the measuring ball 9 and the upper surface 6 of the workpiece.
After cleaning and removing machining debris etc. adhering to the measurement part 6, the injection of the machining fluid is stopped. Here, the measuring ball 9 is moved downward, and the measuring ball 9 and the upper surface 6 of the workpiece 6 are
When it comes into contact with b, the feeding is stopped, and the position at this time is memorized by the CNC device 52. Next, the detector 8 is moved to bring the measurement sphere 9 closer to the bottom surface 6c of the processing section 10. At this time, machining fluid is injected from the nozzles 36 and 37 to wash and remove dust adhering to the measurement ball 9 and machining debris accumulated on the bottom surface 6c of the workpiece 10, and then the machining fluid jetting is stopped. do. After that, the measuring ball 9 is moved further downward, and the measuring ball 9 is placed in the processing section 10.
When it comes into contact with the bottom surface 6c, the feed is stopped and the position at that time is stored in the CNC device.

Next, the clamping by the clamping devices 29, 30 is released, the cylinder 23 is actuated to retract the detector 8 to the rising end, and the pneumatic drive device 60 is actuated to clamp the clamping devices 29, 30. Here, the depth of the machined part is calculated by using the CNC machine 52 to calculate the difference between the measured value of the top surface of the workpiece and the measured value of the bottom face of the machined part, which are stored in the CNC machine as described above. If the calculated value is smaller than a predetermined value, processing for the insufficient amount is performed again. Further, if the value is a predetermined value, the machining is finished or the electrode 4a attached to the electrode holder 3a is replaced by the AEC device 14, and the same machining and measurement as described above are repeated for a new machined part.

In this embodiment, only the depth direction of the machined portion, that is, the Z direction has been described, but measurements in the XY directions can be performed in the same way.

The series of processing and measuring operations described above are sequentially executed according to a program input to the CNC device.

In the above embodiment, the detection means using a detector is arranged on one side of the processing head, but as shown in FIG. 3, it may be arranged on both sides of the processing head, or a plurality of detection means may be arranged. However, the machining fluid supply device, the machining fluid supply pipe, and the AEC device are not shown in FIG. This method is effective when the movement stroke of the processing table is not sufficient. That is, when a range that cannot be measured with one detector occurs, that range can be measured using another detector.

Furthermore, in the above embodiment, an air cylinder is used as a means for advancing and retracting the detector, but an actuator such as a hydraulic cylinder or an electric motor may be used as long as the electrode and the detector change their positions relative to each other during machining and measurement. Just drive it.

Further, in the above embodiment, two nozzles are used, but one or a plurality of nozzles may be arranged to spray the machining liquid toward the measuring ball and the measuring section, respectively.
Moreover, if the nozzle is positioned to the machining area not only during measurement but also during machining, machining debris and the like can be removed by injecting machining liquid. Furthermore, compressed air may be used instead of the machining fluid. Furthermore, it is also possible to separate multiple nozzles into one for compressed air and one for machining fluid, spray the machining fluid for cleaning, and then spray compressed air to dry the surface of the measuring section before measurement. .

Furthermore, even if the machining fluid is discharged from the machining tank via the machining fluid recovery pipe, if the machining section remains pocket-shaped,
Machining liquid with floating machining waste remains in the machining area. Therefore, if high-precision machining is required, it is necessary to remove the machining liquid in which the machining debris is floating. Although it is possible to remove it by spraying compressed air or clean machining fluid from the nozzle shown in FIG. 1, it is difficult to completely remove it if the machining part is deep. In such a case, a method of providing processing suction means as shown in FIG. 4 can be considered. In FIG. 4, members having the same functions as those in FIG. 1 are given the same numbers.
In FIG. 4, a cylinder 71 is provided on the plate 31 so as to be parallel to the rod-shaped body 26. 72 is a piston rod that engages with the cylinder 71. The upper end of the piston rod 72 is connected to an absorption device 74 via a pipe 73. 75 is a drive device connected to the cylinder 71, which drives the piston rod 7 by changing the pressure inside the cylinder 71.
2. Perform positioning. The operation of the above device will be explained below. During machining, if machining liquid has accumulated at the bottom of the machining section, the piston rod 72 as a suction member is moved by the drive device 75, and the machining fluid is removed from the machining section 6a.
The tip 72a of the piston rod 72 is located near the bottom of the piston rod 72.
position. Next, the suction device 74 is activated to absorb the machining fluid containing floating machining waste accumulated at the bottom of the machining section 6a from the tip 72a of the piston rod.
Remove. Next, the piston rod 72 is raised to the upper end by the driving device 75. After that, the measuring section is cleaned, measured, and processed. According to this device, even when the machining section has a deep pocket shape, it is possible to easily remove the machining liquid containing floating machining waste remaining at the bottom of the machining section.

〔Effect of the invention〕

As described above, the present invention includes a machining head holding an electrode for electric discharge machining a machining part of a workpiece, a machining tank for immersing the workpiece in a machining liquid, and a machining tank that advances and retreats into the machining part independently of the electrode. a detector for measuring the machining part by measuring the machining part; a means for supplying and recovering machining liquid in the machining tank; a nozzle for injecting fluid or gas to the machining part and/or the detector; An electrical discharge machining device is proposed that includes a suction device having a suction member that sucks machining liquid and foreign matter, and a drive device that drives the suction member of the suction device to the machining portion of the workpiece relative to the detector. By doing this, when measuring with the detector after machining the machining part of the workpiece, the suction member (piston rod 72) of the suction device is moved into the machining part 10 of the workpiece 6 by the drive device 75. The machining fluid in the machining section 10,
Machining waste could be removed by suction, and the machined part could be measured accurately, and as a result, the workpiece could be machined with high accuracy.

Furthermore, according to the present invention, by configuring the piston rod 72 of the suction member to move relative to the detectors 8 and 9, the suction member can be moved to the measurement location of the workpiece before measuring the detectors. After the suction operation is performed, the suction member can be moved to a position away from the detector and the detection operation can be performed, making it possible to prevent interference between the suction member and the detector.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing one embodiment of the present invention, and FIG. 2 is a block diagram of the embodiment shown in FIG. FIG. 3 is a schematic diagram when two detectors are provided in FIG. 1. FIG. 4 is a schematic diagram showing a detector portion in another modification, and FIG. 5 is a schematic diagram of a processing head portion in a conventional example. 1... Processing head, 4... Electrode, 6... Processed part, 8
...detector, 9...measuring bulb, 14...automatic electrode exchange device (AEC device), 23...pneumatic cylinder, 24...piston rod, 29, 30...clamp device, 33...
Processing liquid supply device, 36, 37... Nozzle, 72... Piston rod (suction member) 74... Suction device, 25
...Drive device.

Claims (1)

[Scope of Claims] 1. A machining head holding an electrode for electric discharge machining a machining part of a workpiece, a machining tank for immersing the workpiece in a machining fluid, and a machining head that moves forward and backward into the machining part independently of the electrode. a detector for measuring the machining section by using a detector; a means for supplying and recovering machining fluid in the machining tank; a nozzle for injecting fluid or gas to the machining section and/or the detector; A discharge characterized by comprising: a suction device having a suction member that suctions liquid and foreign matter; and a drive device that drives the suction member of the suction device to the processing portion of the workpiece relative to the detector. Processing equipment.