JPH0341300B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a steady rest opening/closing control device for commanding the opening/closing timing of a steady rest used in shaft work machining.

[Conventional technology]

When machining long workpieces such as shafts, the workpiece is often held with a steady rest at one or more locations in the middle in order to stabilize the machining, but once machining starts, this steady rest may interfere with the tool. Therefore, the movement of the tool must be temporarily stopped before and after the steady rest, which reduces machining accuracy and increases cycle time. especially,
When thread cutting is performed using an NC device, once the process is stopped, it is impossible to continue the process again.

[Problem that the invention seeks to solve]

In view of the above-mentioned problems, an object of the present invention is to automatically open the steady rest at the optimum timing without stopping the tool when the tool comes close to the steady rest, and to prevent the steady rest from automatically opening when the tool passes the steady rest. An object of the present invention is to provide a steady rest opening/closing control device that automatically closes a stop.

[Means and actions for solving problems]

In order to achieve the above object, the present invention arranges a plurality of steady rests at predetermined positions within the movable range of the tool post, inputs the positions into a storage means using the position coordinates of the tool post, and each The present invention is characterized by comprising a determining means for calculating the area of interference of the steady rest with respect to the movement of the turret and determining the optimum timing for opening and closing the steady rest.

Examples Hereinafter, the present invention will be explained in detail with reference to examples and drawings.

FIG. 1 is a configuration diagram showing an example of a steady rest opening/closing control device embodying the present invention.

FIG. 2 is a side view showing an example of a steady rest mechanism suitable for implementing the steady rest opening/closing control device. First, the steady rest mechanism will be explained. In FIG. 2, the steady rest is composed of three roller arms R operated by a cylinder D attached perpendicularly to the workpiece W, and holds the workpiece W from three sides. Figure 3 is a partially enlarged view of the same type of steady rest mechanism, in which a workpiece W held by three roller arms R is machined with a tool T. The dimensions are larger than the interval between the roller arms that hold the workpiece W, causing interference. Figure 4 is a diagram that similarly shows the relationship between the workpiece, tool, and steady rest. The workpiece W is fixed by the chuck A and the center C, but since the workpiece W is long, "swaying" may occur. This is prevented by two steady rests F1 and F2. However, when the tool T starts machining from the center side, interference occurs at the steady rests F1 and F2, as explained in FIG. 3.

To prevent this interference, the steady rest can be opened when the tool comes close to the steady rest, and closed when the tool passes, but the optimal timing to do this automatically is shown in Figure 5. As shown below. In Fig. 5, when moving the tool in the +P direction in the Z coordinate system, if point a, which is the coordinate value SP, is the position of the n-th steady rest, then ZP is the interference area from point b to point c. becomes. However, since it takes time t to release the steady rest, it is necessary to command the steady rest to be released at point d, which is before point b, but the distance is determined by the above-mentioned time t and tool movement speed V.
It is the product of Therefore, the position P of the tool that issues the command to open the steady rest is when the following conditions are satisfied. In other words, this is the condition for issuing a command to open the steady rest when the tool comes to a position in front of d.

SP-ZP/2-|V|×t<P In addition, the steady rest closing command is issued when the following conditions are satisfied.

SP+ZP/2<P Note that the interference area is determined when the following conditions are satisfied.

SP-ZP/2<P<SP+ZP/2 The embodiment of the present invention shown in FIG. 1 controls the opening and closing of the steady rest based on this principle. In FIG. 1, the steady rest opening/closing control device includes a CPU (central processing unit) 1, a processing program memory 101,
NC machining program memory 102, steady rest position data memory 103 that stores the coordinate value SP for each steady rest, and current value data memory (D-RAM) 1 that constantly rememorizes the current position P of the tool.
04. Speed data memory (D-RAM) 10 that continues to store the tool moving speed V with positive and negative signs
5. Steady rest opening time data memory 106 that stores the opening time t from the closed state to the fully open state of the steady rest as a parameter, and the steady rest position data of the number when determining whether to open or close the steady rest of the number. The relevant number steady rest position data memory 107 temporarily registers the SP, the interference area data memory 108 stores the interference area ZP of the steady rest as a parameter, and the steady rest is transmitted from the CPU 1 to the relevant steady rest when executing the release judgment of the relevant steady rest. Confirmation memory 109 that stores the fact that an opening command has been issued using a bit signal, Steady rest opening/closing judgment circuit 1
10, a control unit consisting of an interference area determination circuit 111, and a display 141 and a keyboard 14 as peripheral devices for inputting and outputting each data to these.
2 and these input/output interfaces 14
3. Tool X-axis and Z-axis axis feed motor 151
and 161 servo amplifiers 152 and 162
interpolators 153 and 163 for controlling the motors, and converters 154 and 16 for extracting speed components from the pulse train of feedback signals from each of the motors.
4. It is composed of an input interface 171 for inputting signals from the position memory push button and release confirmation push button of each steady rest, and an output interface 172 for outputting an opening/closing command signal for each steady rest.

FIG. 6A shows the steady rest opening/closing judgment circuit 110.
FIG. 6B is an explanatory diagram showing the determination content of the interference area determination circuit 111. FIG. In Figure A, the judgment circuit 110 is
The current tool position P, tool movement speed V, steady rest opening time t, steady rest position SP, and interference area width ZP are input from the angle data memory, and the tool movement direction is (+) direction and (-) direction. The direction cases are sorted by AND gate matching, and the fifth
Based on the calculations and comparisons explained in the figure, the moment when the tool reaches the position in front of the interference area considering the steady rest release time from either direction is determined, and the release command (OPN) is issued from the or gate only in the corresponding direction.
Similarly, the moment when the tool leaves the interference area in either direction is determined and output as a closing command (CLS) from another OR gate. In addition, in FIG. 6B, the judgment circuit 111 receives the current tool position P, steady rest position SP, and interference area width ZP from each of the data memories, and determines whether the tool is determined by the calculation and comparison described in FIG. The AND gate confirms that it is inside both ends of the interference area, and outputs an in-area signal (INZ). The outputs from the two decision circuits are output as bit signals.

The CPU 1 issues a steady rest release command to the steady rest via the output interface 172, and confirmation of the opening of the steady rest is performed via the force interface 171.
is sent to the steady rest release confirmation memory 109 via the steady rest release confirmation memory 109. This memory is "1" when the steady rest release command is issued, and is "0" when it is not issued, and the inverter 121 inverts this and outputs the above-mentioned in-area signal (INZ) and another one. One and one
Since the match is made by the gate 112, when "1" indicating that the tool is in the area matches "1" indicating that the steady rest is not released, the AND gate 11
“1” is output as signal ILK from 2 to warn of interference between the tool and steady rest, and the tool axis feed motor 1
It is used as a signal to stop 61.

FIG. 7 is a flowchart showing an example of a procedure for importing each steady rest position data into the above-mentioned steady rest opening/closing control device. In Fig. 7, the start of the flowchart is performed with the cutting edge of the tool aligned approximately with the center of the steady rest roller of the corresponding number, and the steady rest position memory push button of the corresponding number shown in Fig. 1 is pressed. Then, the current value of the Z-axis is substituted into the corresponding number column of the steady rest position data memory 103 from the interpolator 163 which is a tool position control circuit.

Furthermore, if an engagement pin built into the steady rest that can move forward and backward is engaged with the base of turret B, and the steady rest can be moved by movement of the turret in the Z direction, positioning can be achieved by programmable movement of the steady rest. The location can be automatically imported into the location data memory 103.

FIG. 8 is a flowchart showing an example of a procedure for key-inputting each data into the steady rest opening/closing control device of the above embodiment. In FIG. 8, as in the case of FIG. 7, after checking the position of the cutting edge of the tool and the corresponding number push button, the keyboard is pressed while referring to the data displayed on the CRT screen of the display 141 in FIG. Interference area data by 142
Input ZP and opening time data t. These two data are stored parametrically in their respective data memories.

The current value P of the tool is taken in real time from the interpolator 163 and stored in the current value data memory 10.
4 is constantly updated. The tool moving speed V may also be updated from the converter 164 to the speed data memory 105 from time to time, or the maximum feed speed may be entered by keying.

FIG. 9 is a flowchart showing the procedure of the processing-in-process judgment process executed based on these data. In FIG. 9, the flow starts when the tool starts moving, and first the position data SP of the first steady rest is taken out from the number-by-number position data memory 103 and the number position data memory 107
The tool current value P is then read into the current value data memory 104 as described above, and furthermore, when the signal from the steady rest release confirmation push button is input to the confirmation memory 109 via the input interface 171. , the CPU 1 instructs the two judgment circuits 110 and 111 to start calculations, and a steady rest opening/closing command is outputted via the output interface 172 unless the above-mentioned alarm occurs. The flow is then repeated for all steady rests in numerical order.

Note that if the interference area is not used as a parameter, but instead is used as a function of the moving speed of the tool, it is also possible to achieve more fine-grained movement without waste.

〔Effect of the invention〕

As explained above, according to the present invention, when a tool approaches a steady rest used for shaft machining, the steady rest is automatically opened and closed at the optimum timing without stopping the tool. A stop opening/closing control device can be provided.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an embodiment of the steady rest opening/closing device according to the present invention, FIG. 2 is a side view of an example of the steady rest mechanism, and FIG. 3 is a partial side view of another example of the steady rest mechanism.
Figure 4 is an explanatory diagram of the relationship between the workpiece, tool, and steady rest, Figure 5 is a diagram of the principle of steady rest opening/closing timing,
FIG. 6 is an internal configuration diagram of the determination circuit, FIGS. 7 and 8 are flowcharts of data input, and FIG. 9 is a flowchart of determination processing. 1... CPU, 103... Steady rest position data memory, 104... Tool current value data memory, 105... Tool speed data memory, 106
... Steady rest release time data memory, 108...
...Interference area data memory, 110... Steady rest opening/closing judgment circuit, 111... Interference area judgment circuit, 1
63...Interpolator (tool current position detection means), 16
4...Converter (tool movement speed detection means), SP
... Steady rest position, ZP ... Interference area width, P ...
Current tool position, V...Tool movement speed, t...Steady rest opening time.

Claims (1)

[Claims] 1. When performing machining while moving a tool along a long workpiece, one or more steady rests that grip the long workpiece are sequentially and automatically temporarily released to prevent runout from interfering with the tool. In the stop opening/closing control device, a steady rest position data memory that stores the grasping position of each steady rest, a steady rest opening time data memory that stores the required opening time for the steady rest to change from a closed state to an open state, Interference area data that stores the interference area width between the steady rest and the tool.
A memory, a tool current position data detection means, a tool movement speed data input means, a steady rest opening/closing judgment circuit that determines when to command steady rest opening/closing from each of the above data, and a steady rest opening/closing judgment circuit that determines whether or not the tool is within an interference area. A steady rest opening/closing control device characterized by comprising an interference area judgment circuit that makes a judgment and a central processing unit that controls these.