JPS5918184B2 - Tool evacuation/return device in case of tool abnormality in machine tools - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic tool evacuation and return device when a tool abnormality occurs in a machine tool.

If a tool abnormality occurs during machining in a numerically controlled machine tool that drives the machine tool by inputting numerical control commands using perforated tape, etc., the abnormality signal is detected, the machine tool is stopped, and the tool is operated manually. After retracting to a predetermined position and replacing the tool, the tool is returned to the original position, and then the machine tool is driven to perform machining based on predetermined numerical control commands from the machining operation in which the abnormality occurred.

However, since such work is a manual operation, it hinders automation and prevents the effective use of the advantages of a numerically controlled machine tool.In addition, the workpiece and the tool interfere with each other when retracting and returning, resulting in damage to the workpiece. This has problems such as leaving traces on the surface.

Therefore, it is possible to automatically retreat and return the tool based on the abnormal signal, but the problem in this case is that the tool must be withdrawn and returned in the same mode for external machining, end face machining, and internal diameter machining. and the workpiece may interfere with each other.

The present invention was made in view of the above circumstances, and its purpose is to prevent interference with the workpiece in any of the cases of outer diameter machining, end face pressure, and inner diameter machining (automatically change the tool based on a tool abnormality signal). An object of the present invention is to provide an automatic tool evacuation/return device when a tool abnormality occurs in a machine tool, which is capable of evacuation and return.

The present invention will be described in detail below with reference to the drawings.

The numerically controlled machine tool 1 includes a grip part 2 that is rotationally driven, a moving table 3 that is reciprocated in the Z direction along a guide 3', and a tool rest 4 that is reciprocated in the X direction. Tool 5 is provided.

6 is an automatic tool changer, which transfers the tool 5 that has been moved to a predetermined position to the tool stored in the tool magazine (chip)
This is a conventionally known structure in which automatic exchange is performed.

Reference numeral 7 denotes a numerical control device (hereinafter referred to as NC), which has a conventionally known structure for giving predetermined operation commands to the numerically controlled machine tool 1 and the automatic tool changer 6 based on an input program.

Reference numeral 8 denotes a workpiece, and the example shows a case where the outer diameter of a stepped round bar is machined.

Reference numeral 9 denotes a tool abnormality detection machine, which has a conventionally known structure for detecting tool abnormality using, for example, electric power of a motor, vibration, etc.

When machining the outer diameter of the workpiece 8 with the tool 5, the NC
The output calculated from the outer diameter nib program input to 7 is sent to the tool rest 1 via the changeover switch 10 and the pulse distributor 11.
Drive motor (hereinafter referred to as X-axis servo motor) 12 and carriage drive motor (hereinafter referred to as Z-axis servo motor) 1
A drive signal is applied to the tool 3 to move the tool 5 from the origin P (XP, ZP) in a predetermined outer diameter machining mode to cut the work 8 with an outer diameter cutter.

In addition, in FIG. 5, the dotted line is the cutting feed, and the solid line is the cutting feed.

Since the above is a conventionally known structure, detailed explanation will be omitted.

Next, referring to FIGS. 2, 3, and 4, an embodiment of the main part of the present invention will be described together with the operation when a tool abnormality occurs at a certain position.

Position C (Xc), which is the odor during processing shown in FIG.

When a tool abnormality occurs in Zc), the tool abnormality detection mechanism 9 sends an abnormality signal R1 to the NC 7 and the changeover switch 10, and the changeover switch 10 changes from the normal position (the position where the command of the NC7 is sent to the pulse distributor 11). Abnormal position (stops sending commands from the NC 7 to the pulse distributor 11, and sends commands from the sequence controller 14 (described later) to the pulse distributor 1)
1).

On the other hand, when the abnormality signal R1 is input to the NC7, the output of the NC7 is stopped, and the current position of the tool at that time, that is, the abnormality occurrence position c (xc, zc), is stored in the current position storage register 16 in the register group 15. , its sequence N
Machining end position B at O (XB=cs ZB)
is stored in the NC command position storage register 17.

The register group 15 also includes a tool retraction position storage register 18 that stores the tool exchange position of the automatic tool changer 6, that is, the retraction position A (xA, ZA) of the tool 5, an X-axis minimum value storage register 19, The retraction position A is a fixed value determined by the installation position of the automatic tool changer 6, etc., and the X-axis minimum value a1 and escape amount t are values determined by the shape of the workpiece 8. be.

Then, each part of the register group 15 is sent to the arithmetic circuit 21.

The arithmetic circuit 21 has first to fifth registers 22, 23, 24,
25 and 26, calculates the save/return mode commands shown in Table 1 below based on the values sent from the register group 15, and sends the results to the sequence controller 14.

That is, the outer diameter mode, end face mode, and inner diameter mode are selected from the mode signal R2 from the NC7 (the embodiment is the outer diameter mode), and the first to fifth registers 2 are selected by the calculation start command R3.
2 to 26 are calculated, and the X and Z values are sequentially sent to the sequence controller 14 in register numbers 1. 2.
3. 4. 3. Changeover switch 10 in the order of 2゜1.5
, the tool 5 is sent to the X-axis servo motor 12 and Z-axis servo motor 13 via the pulse distributor 11 to move the tool 5 diagonally from the abnormality occurrence position C' to the first device E (XD+2aZD), and from the first device E. Move to the second device F (XA, ZD) in the X-axis direction in rapid traverse, and move from the second device F to the evacuation position A (XA, ZD).
, ZA) in rapid traverse in the Z-axis direction, gives the tool exchange signal R4 to the automatic tool changer 6 to exchange the tool, and in response to the tool exchange completion signal R5, moves the tool 5 again in rapid traverse to the second device F, and then After moving from the second device F to the first device E by rapid traverse, it moves to the machining start position D (XD-ZD) by cutting feed (the above is the return path).

The machining start position is t in the Z-axis direction from the abnormality occurrence position C.
The position is closer to the processing start position.

Here, the mode for machining the end face is as shown in FIG. 5, and the mode for machining the inner diameter n0 is as shown in FIG.

Note that in FIG. 6, XF is the X-axis coordinate determined in the inner retreat point determination algorithm.

When the tool 5 moves to the machining start position, the tool 5 is cut and fed to the abnormality occurrence position C according to a command from the sequence controller 14, and a restart command is given to the NC 7 by the operation completion signal R7 of the sequence controller 14, and the changeover switch 10 are stapled in the normal position and processed again using a program manually input to the NC7.

At this time, since the machining start position is closer to the machining start position than the abnormality occurrence position C, the part where the abnormality has occurred can be reprocessed to remove the traces of that part.

Since the present invention is configured as described above, the outer diameter DO machining and the end face 7
J[lI, no matter what machining mode such as internal machining, there is no interference with the workpiece 8 (tool 5 based on tool abnormality)
can be automatically evacuated and restored.

In addition, the switching means 1 switches the evacuation/return path in the event of an abnormality from the sequence controller 14 and the path in the normal state by the NC 7.
0 and sends it to the servo motor drive circuit, and the calculation circuit 21 calculates the evacuation/return path in the machining mode and sends it to the sequence controller 14 from each part of the register group 15 according to the specified mode of NC7. (The tool 5 can be automatically evacuated and returned when a tool abnormality occurs with a simple operation.)

Moreover, since the position where the tool abnormality occurs can be re-JOIed at the time of return, the position where the tool abnormality has occurred can be processed correctly.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is an overall schematic explanatory diagram, FIG. 2 is a diagrammatic configuration explanatory diagram of the main parts, FIG. 3 is an explanatory diagram showing a workpiece processing Everturn, and FIG. , Figure 5, Figure 6
The figure is an explanatory diagram of tool retraction and return paths during outer diameter machining, end face machining, and inner diameter machining. 5 is a tool, 6 is an automatic tool changer, 7 is an NC'', 8 is a workpiece, 9 is a tool abnormality detection mechanism, 10 is a changeover switch, 1
2.13 is the X axis or Z axis? 14 is a sequence controller, 15 is a register group, 16 is a tool current position storage register, 17 is an NC command position storage register,
18 is an evacuation position storage register, 19 is an X-axis minimum value storage register, 20 is an escape amount storage register, and 21 is an arithmetic circuit.

Claims (1)

[Claims] 1. A tool abnormality detection mechanism 9 that detects a tool abnormality, a sequence controller 14 that performs tool evacuation and return control when a tool abnormality occurs, an NC 7 that gives commands when a tool abnormality occurs, a servo motor drive circuit that drives the tool 5 based on NC70 command information,
A sequence controller 140 command is provided between the servo motor drive circuit, the sequence controller 14 and the NC7, and when the tool abnormality detection mechanism 9 detects a tool abnormality, the sequence controller 140 command is sent to the servo motor drive circuit, and when normal, the command of the NC7 is sent to the servo motor drive circuit. switching means 10, tool current position storage register 16, and NC command position storage register 17.
and a register group 15 comprising a tool retraction position storage register 18, an X-axis minimum storage register 19, and an escape amount storage register 20, from each part of the register group 15, the evacuation return path in the machining mode is determined by the specified mode of the NC 7. and an arithmetic circuit 21 that performs calculations and sends the resulting values to the sequence controller 14, and the evacuation path from the arithmetic circuit 21 to the controller 14 is the NC7
Tool evacuation and return when a tool abnormality occurs in a machine tool, which is different from the path according to the above, and the return path is a path for returning to a position slightly distant from the tool abnormality occurrence position and remachining the tool abnormality occurrence position. Device.