JP4166498B2 - Control device for chip biting prevention sequence during attachment replacement - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
More particularly, the present invention relates to a machine tool such as a horizontal milling boring machine having a function of automatically replacing an attachment with respect to a spindle head ram. About.
[0002]
[Prior art]
In a horizontal milling machine, the column is fed to the left and right along the bed guide (X-axis), the spindle head moves up and down (Y-axis) along the column guide, and the ram built into the spindle head is It is sent back and forth in the horizontal direction (Z-axis).
[0003]
In the horizontal milling boring machine, various attachments are used to add various machining functions. There are various types of attachments such as an angle head, a facing head, a universal head, and a five-axis head, and an appropriate one is attached to the ram according to the processing mode.
[0004]
The attachment is structured such that the end face of the ram is attached as an attachment face, and attachment / detachment mechanisms with respect to the attachment are provided at the four corners of the end face of the ram. Usually, when the attachment is not attached, a cover for protecting the attachment attachment surface is attached to the end face of the ram.
[0005]
[Problems to be solved by the invention]
While the workpiece is being machined by the horizontal milling boring machine, the ram is fed out, so that chips gradually accumulate on the upper surface of the ram that has come out of the spindle head.
[0006]
Chip biting is a major problem in the case of machining using attachments. During the attachment replacement operation based on the attachment replacement command, if the ram is attached to the attachment mounting surface of the ram end face due to vibration or the like, the chips will bite the chip. As a result, the attachment is slightly inclined as compared with the case of normal attachment, and an error occurs in the position of the tool attached to the attachment, which directly leads to a decrease in processing accuracy and a processing failure.
[0007]
Conventionally, in order to prevent such chips from being caught, an operator who monitors a machining state manually cleans a ram before an attachment replacement command is executed.
[0008]
Accordingly, an object of the present invention is to eliminate the problems of the prior art, and to control the attachment replacement sequence so as to automatically remove the lumped chips when replacing the attachments, thereby ensuring that the chips are caught. An object of the present invention is to provide a control device for a chip biting prevention sequence at the time of replacement of an attachment which can be prevented.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is an NC machine tool comprising a spindle head having a ram that holds the spindle and can be advanced and retracted in the horizontal direction, and replaces the attachment attached to the end face of the ram. An apparatus for controlling an operation sequence for preventing attachment from biting chips between ram end faces when cleaning is performed, the cleaning medium spraying means for spraying the cleaning medium from the nozzle toward the ram, and the cleaning medium spraying A solenoid valve for controlling the ejection and stop of the cleaning medium of the means, and sequence control means for controlling the operation of each part of the machine tool constituting a series of steps of automatic attachment replacement, the sequence control means from the NC device When an attachment replacement command is given, it is based on a macro program that describes a series of automatic attachment replacement sequences. Controlling the sequence of Attachment automatic exchange, the macro program, chip bite prevention sequence for opening and closing the solenoid valve is added in conjunction with the movement of the ram, the chip bite prevention sequence the solenoid valve An operation for opening and starting ejection of the cleaning medium, an operation for retracting the ram to the retreat limit, an operation for feeding the ram to a predetermined position, and an operation for closing the electromagnetic valve and stopping the ejection of the cleaning medium. In addition, after the cleaning medium is stopped, the process shifts to an attachment replacement sequence .
[0011]
Further, the invention according to claim 2 is the invention according to claim 1, wherein the cleaning medium ejecting means covers the periphery of the opening on the front surface of the spindle head through which the ram enters and exits the cover having a window portion into which the ram is loosely fitted. And a nozzle for ejecting the cleaning medium toward the ram is disposed in the cover.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a control device for a biting prevention sequence during attachment replacement according to the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows a horizontal milling machine to which the present invention is applied. Reference numeral 10 indicates a column. The column 10 moves along the guide of the bed 11 with the X axis as the control axis. A spindle head 12 moves up and down along the guide surface of the column with the Y axis as the control axis. A ram 14 is provided on the spindle head 12 so as to be movable in the horizontal direction with the Z axis as a control axis. The main shaft 16 is incorporated and held in the ram 14. 13 is an automatic tool changer, and 15 is a tool magazine. Reference numeral 17 denotes an attachment stocker in which various attachments are stored.
[0013]
Next, FIG. 2 shows the outer shape of the cover of the chip biting prevention device that blows air toward the ram 14 as a cleaning medium and blows off chips.
The ram 14 is a square ram having a square cross-sectional shape, and a closed-type ram guide surface is formed on the spindle head 12 and has a highly rigid structure. The cover 20 constituting the chip biting prevention device is attached to the spindle head 12 so as to surround the opening 21 through which the ram 14 enters and exits from the front side of the spindle head 12 from three sides.
[0014]
In this embodiment, the cover 20 is a cover made of a metal plate having an overall U shape corresponding to the contour of the ram 14. A large rectangular window 22 is formed on the front. The ram 14 is loosely fitted in the window portion 22 so that it can move smoothly. Specifically, a predetermined gap s is set between the three side edges of the window 22 and the upper surface and both side surfaces of the ram 14. This gap is preferably about 0.2 mm. The gap s is present in order to scrape off the edge of the window 22 like a scraper and to remove chips entering from the gap with air as will be described later. The lower part of the cover 20 is open. In FIG. 2, reference numeral 28 is an attachment attaching / detaching mechanism incorporated in four corners of the end face of the ram 14, and 30 is an attachment.
[0015]
Next, in FIG. 3, the cover 20 includes an upper nozzle 24 disposed at a position above the upper surface of the ram 14, and side nozzles 25, 25 respectively disposed on the left and right side surfaces of the ram 14. A total of three nozzles are provided. The mounting position of the upper nozzle 24 is made to correspond to the position of the key groove 26 formed at the tip of the ram 14 for alignment with the attachment. Similarly, the mounting position of the side nozzle 25 corresponds to the height of the key groove 27. When the ram 14 is at the position shown in FIG. 3, the upper nozzle 24 is oriented toward the key groove 26, and similarly, the side nozzle 25 is oriented toward the key groove 27. As for the upper nozzle 24 and the side nozzle 25, a ring-shaped orifice is built in the nozzle, and air is blown out at the surface of the conical nozzle at a speed of sound to induce secondary air in the vicinity to increase the air by about 20 to 25 times. It is preferable to use a nozzle having an amplifying function for amplifying and ejecting.
[0016]
In FIG. 3, reference numeral 32 is an electromagnetic direction switching valve for switching between air and cutting agent. An air supply pipe 33 inside the spindle head 12 is connected to the A port of the electromagnetic direction switching valve 32. A pipe 35 connected to the upper nozzle 24 and the side nozzle 25 is connected to the P port.
[0017]
In FIG. 3, reference numeral 40 is an NC device, and 42 is a programmable sequence controller (hereinafter referred to as PLC), which is a peripheral device such as an automatic tool changer 13, a tool magazine 15, an attachment stocker 17, and an attachment attaching / detaching mechanism 28. And the ON / OFF of the solenoid 32a of the electromagnetic direction switching valve 32 is controlled.
[0018]
Next, FIG. 4 is a flowchart showing a sequence of an attachment exchange macro program in the PLC 42. Hereinafter, the sequence of the chip biting prevention operation at the time of replacing the attachment will be described with reference to FIGS. 4 and 5.
[0019]
As shown in FIG. 5 (a), when the attachment 30 is attached to the ram 14 and the machining is continued, chips scattered from the tool to the periphery gradually accumulate on the upper surface of the ram 14 that is fed out. .
[0020]
If the attachment 30 is replaced with another attachment in this state, there is a risk of chipping in due to vibration or the like when replacing the attachment 30. Therefore, before the attachment replacement operation is actually performed, the upper nozzle 24 Then, a series of sequences in which air is ejected from the side nozzle 25 to blow off chips on the upper surface and both side surfaces of the ram 14 are controlled.
[0021]
In FIG. 4, when a machining end signal is received from the NC device 40 (yes in step S10), the process proceeds to step S11. If there is an M code attachment exchange command, for example, the macro A assigned as M80 is called and executed. Then, the chip biting prevention operation is performed according to the following sequence.
[0022]
First, the solenoid 32a of the electromagnetic direction switching valve 32 is excited to start air ejection from the upper nozzle 24 and the side nozzle 25 (step S12), and then the ram 14 is slowly retracted to the retreat limit (step S13). During the retreat of the ram 14, as shown in FIG. 5B, the edge of the window portion 22 scrapes off the chips, and the air ejected from the upper nozzle 24 and the side nozzle 25 flows on the upper surface and both left and right side surfaces of the ram 14. Foreign matter such as chips that are blown obliquely and entered through the gap s are blown off from the cover 20 to the outside. In this case, since the air is ejected from the upper nozzle 24 and the side nozzle by inducing and amplifying the surrounding air, the foreign matter can be blown off reliably.
[0023]
Thus, as the ram 14 moves backward, foreign matter such as chips on the upper surface and both the left and right side surfaces of the ram 14 is blown away from the end to the tip.
[0024]
As shown in FIG. 5C, when the ram 14 approaches the retreat limit, air is directly blown around the key grooves 26 and 27 where foreign matter such as chips is most likely to accumulate in the ram 14 to remove the foreign matter.
[0025]
When the ram 14 is retracted to the retreat limit, the ram 14 is extended about 50 mm (step S14). Thereafter, the solenoid 32a of the electromagnetic direction control valve 32 is demagnetized, and the ejection of air from the upper nozzle 24 and the side nozzle 25 is stopped (step S15).
[0026]
As described above, the ram 14 travels backward, and foreign matter such as chips is blown off by air over the entire ram 14 to complete the cleaning of the entire ram.
[0027]
Thereafter, in FIG. 1, the column 10 is moved to the replacement position facing the attachment stocker 17 (step S16), and the ram 14 is moved back and forth with respect to the attachment stocker 17, and the attachment 30 is followed according to the general sequence of automatic attachment replacement. Are exchanged (step S17). During this time, since the cleaning of the ram 14 has been completed as described above, the attachment 30 can be replaced smoothly without biting foreign matter such as chips between the attachment surface of the end surface of the ram 14 and the attachment 30. it can.
[0028]
【The invention's effect】
As is apparent from the above description, according to the present invention, the chips attached to the ram can be reliably removed using the movement of the ram prior to the replacement of the attachment, and the biting of the chips can be reliably prevented. be able to.
[Brief description of the drawings]
FIG. 1 is a front view of a horizontal milling boring machine to which a chip biting prevention sequence control device at the time of attachment replacement according to the present invention is applied.
FIG. 2 is a perspective view of a spindle head to which a cover containing a nozzle that ejects air to prevent chipping is attached.
FIG. 3 is an explanatory view showing nozzles in the cover of FIG. 2;
FIG. 4 is a flowchart of a chip biting prevention sequence.
FIG. 5 is an explanatory diagram of a chip biting prevention operation according to the present embodiment.
[Explanation of symbols]
10 column 11 bed 12 spindle head 14 ram 15 tool magazine 16 spindle 17 attachment stocker 20 cover 22 window 24 upper nozzle 25 side nozzle

Claims (2)

In an NC machine tool equipped with a spindle head that holds a spindle and has a ram that can move forward and backward in the horizontal direction, when the attachment attached to the end face of the ram is replaced, the attachment prevents the chips from biting between the end faces of the ram. An apparatus for controlling a sequence of actions to be performed,
Cleaning medium ejection means for ejecting the cleaning medium from the nozzle toward the ram;
A solenoid valve for controlling the ejection and stop of the cleaning medium of the cleaning medium ejection means;
Sequence control means for controlling the operation of each part of the machine tool constituting a series of steps of automatic attachment replacement,
When an attachment exchange command is given from the NC device, the sequence control means controls an automatic attachment exchange sequence based on a macro program that describes a series of automatic attachment exchange sequences. A chip biting prevention sequence that opens and closes the solenoid valve in conjunction with the
The chip biting prevention sequence includes an operation of opening the electromagnetic valve and starting ejection of the cleaning medium, an operation of retracting the ram to a retreat limit, an operation of feeding the ram to a predetermined position, and closing the electromagnetic valve. And an operation for stopping the ejection of the cleaning medium, and the control device for the chip biting prevention sequence at the time of replacing the attachment, wherein after the cleaning medium is stopped, the process proceeds to an attachment replacement sequence.   The cleaning medium ejecting means attaches a cover having a window part into which the ram is loosely fitted so as to cover the periphery of the opening on the front surface of the spindle head where the ram enters and exits, and a nozzle that ejects the cleaning medium toward the ram. The control device for a chip biting prevention sequence when replacing an attachment according to claim 1, wherein the control device is arranged in a cover.

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