JPH03256649A - Work processing device - Google Patents

Abstract

PURPOSE:To perform proper correction of processing in a rapid displacement state during the start-up of a device by deciding a correction amount through computation of an increase amount of a tolerance based on a detecting result by a detecting means during a period between the start-up and stabilization of the device, and correcting operation of a processing part. CONSTITUTION:The size of a work conveyed to a work carriage conveyor 4 is accurately measured by a measuring device 6. The tolerance of a work obtained at processing at two times before a current processing is stored in a first measurement memory M1 and the tolerance of a work obtained at preceding processing in a second measurement graduation M2. When the actual number (n) of operating times does not attain the number N of operating times required for bringing of a processing device into a stabilizing state, a correction value is determined from the values of the measurement memories M1 and M2 responding to tolerances A at two times before and a preceding tolerance B, and processing is carried out by using the correction value.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a workpiece processing apparatus, and particularly to a workpiece processing apparatus in which stability during startup is a problem.

[Conventional technology]

For example, a workpiece processing device including a lathe includes a lathe that has a main shaft for holding the workpiece and a turret equipped with a tool, a loader for loading and unloading the workpiece (loader), and a measuring device for measuring the shape of the workpiece after machining. It is known that it has the following.

In this type of workpiece processing apparatus, a loader transports the workpiece to the main shaft of the lathe. In a lathe, a workpiece is rotated by rotation of a main shaft, and a predetermined processing is performed on the workpiece by a tool provided on a turret. The processed workpiece is carried out by a loader, and its shape is measured by a measuring device. Based on the measurement results from the measuring device,
The processed workpiece is transported as a product or discarded as a defective product.

[Problem to be solved by the invention]

Generally, in workpiece processing equipment, tolerances occur for each workpiece due to various factors. When a machine tool is in a stable state, its tolerances appear randomly.

In order to reduce this tolerance, a method of adding correction to the machining operation is, for example, the average value (A+B)/2 of the tolerance A of the workpiece that was machined two times before and the tolerance B of the workpiece that was machined last time. One possible method is to calculate this and use it as a correction value.

This makes it possible to correct errors that tend to be erasable among randomly occurring errors.

However, in general machine tools, the thermal displacement during startup is large. As shown in FIG. 5, when the device starts up, the thermal displacement increases rapidly. The direction of this displacement is
Generally, there is a certain tendency, but with the above-mentioned correction method, the thermal displacement is too large and sufficient correction cannot be made.6 In other words, as shown in Fig. If the average value of I'll leave. In addition, especially while the thermal displacement rate is high,
Since the amount of correction is insufficient, the error increases cumulatively.

An object of the present invention is to provide a workpiece machining device that can perform appropriate machining correction in a state of rapid displacement, such as when the device is started up.

[Means to solve the problem]

The workpiece processing apparatus according to the present invention includes a processing section that processes the workpiece, a detection means that detects the tolerance of the workpiece after processing, and a correction section that corrects the operation of the processing section from the start of the apparatus until it becomes stable. It is equipped with The correction means calculates the amount of increase in the tolerance based on the detection result by the detection means from the start of the apparatus until it becomes stable, determines the amount of correction from the amount of increase, and corrects the operation of the processing section using the amount of correction. It is.

[Effect]

In the workpiece processing apparatus according to the present invention, the workpiece is processed by the processing section. The tolerance of the processed workpiece is detected by the detection means.

The correction means corrects the operation of the processing section from the start of the apparatus until it becomes stable. At this time, the amount of increase in the tolerance is calculated based on the detection result by the detection means. Then, a correction amount is determined from the increase amount, and the operation of the processing section is corrected using the correction amount. In this case, since the amount of correction is determined from the amount of increase in the tolerance, sufficient and accurate correction can be made even at the start-up, where rapid displacement in a certain direction occurs. Therefore, even after starting up until it stabilizes,
The equipment can perform accurate processing.

〔Example〕

FIG. 1 is a front view of one embodiment of the present invention.

In the figure, this workpiece machining system includes a two-axis drawing board I, a gantry loader 2 for loading and unloading the workpiece into and out of the two-axis lathe I, and a workpiece loading conveyor 3 for supplying unprocessed workpieces. It mainly includes a workpiece unloading conveyor 74 for unloading processed workpieces, a measuring device 6 provided in the middle of the workpiece unloading conveyor 4, and a control panel 7 for issuing commands to this system.

A two-spindle lathe l has a pair of spindles 9 for holding and rotating a workpiece. IO and support shaft 9. A pair of turrets 11 equipped with tools for machining workpieces held at lO
(only one is shown).

A horizontally extending guide rail 13 is arranged above the front part of the two-spindle lathe l. The gantry loader 2 is attached to the guide rail 13 so as to be movable in its extending direction. The gantry loader 2 includes a chuck 14 for holding a workpiece disposed at the lower end and a moving mechanism 1 disposed at the upper end.
5. In addition, when the gantry loader 2 is arranged at the prisoner end of the guide rail I3, the chuck 14 of the gantry loader 2 corresponds to the downstream end of the workpiece carrying-in conveyor 3. Furthermore, when the gantry loader 2 is arranged at the center of the guide rail 13, the chuck 14 corresponds to the tip of the support shaft 9.10. Further, when the gantry loader 2 is placed at the rejuvenating end of the guide rail 13, the chuck 14 corresponds to the upstream end of the workpiece delivery conveyor 4.

A measuring device 6 disposed midway through the flow path of the workpiece carry-out conveyor 4 is for measuring the dimensions of the workpieces carried out to the workpiece carry-out conveyor 4.

For example, the outer diameter of the male mold is accurately measured by the measuring device 6. Note that the measuring device 6 is provided with an NG chute (not shown), from which workpieces determined to be defective as a result of measurement are discharged.

The control panel 7 is arranged so as to protrude from the two-spindle lathe l toward the front in FIG. The control panel 7 includes a keyboard 21 for inputting commands, a CRT 22 for displaying operating status, etc., and a tape reader 23 for inputting NC programs.

Furthermore, a control section 20 shown in FIG. 2 is housed within the control panel 7. This control section 20 includes a microcomputer for controlling the entire Kanji system, and performs control operations to be described later.

A keyboard 21 , a CRT 22 , and a tape reader 23 are connected to the control unit 20 via an I10 port 24 . In addition, the I10 port 24 is connected to the drive unit (servo motor, hydraulic pump, etc.) of the processing unit 25 including the main shaft 9.10 and the turret 11, the drive unit of the gantry loader 2, the measuring device 6, and other input/output devices. The parts are connected.

Next, the operation of the above-mentioned Kanji system will be explained in Figures 3A and 3.
This will be explained according to the control flowchart shown in Figure B.

When the program starts, step Sl in FIG.
In this step, initial settings such as setting the turret 11 and gantry loader 2 to initial positions are performed. In addition, here, the first measurement memory Ml and the second measurement memory Ml used in later control are described.
This mark is set in the measurement memory M2, and the number of times n is set to 0. In step S2, the NC program is read using the tape reader 23. In step S3, the number of operations N corresponding to the period in the rising state is set based on the input value from the keyboard 21. Here, the period required for the device to shift from a startup state to a stable state is determined in advance through experiments as the number of operations. The operator uses the keyboard 21
Using the numeric keys, input the value as the number of operations N. When the input of the number of operations N is completed, an operation start command is awaited in step S4.

When the operator inputs an operation start command from the keyboard 21, the program moves to step S5. In step S5, the first NC step of the NC program stored in step S2 is read. Then, in steps S6 to Sll, it is determined what kind of NC step has been read. In step S6,
It is determined whether the NC step is a step of a machining start command. In step S7, it is determined whether the step is a step of a machining operation command.

In step S8, it is determined whether the command is for the gantry loader 2 to carry in a workpiece. In step S9, it is determined whether or not this is a step for instructing the gantry loader 2 to carry out a workpiece.

In step SIO, it is determined whether the command is for processing other than these. In step Sll, it is determined whether the step is a step that means the end of the machining operation. Note that if the read NC step does not mean the end of the operation, the program returns to step S.
From ll, the process returns to step S5 and the next NC step is read.

Here, if the NC step read in step S5 is a step that instructs the workpiece loading operation,
The program moves from step S8 to step 312. In step S12, the gantry loader 2 carries out a workpiece loading operation. Here, the gantry loader 2 moves on the guide rail 13, and the chuck 14 grips an unprocessed workpiece present on the workpiece carry-in conveyor 3. Then, a workpiece is mounted on either of the support shafts 9 and 10. This completes the work loading operation,
The program returns to the main routine.

If the step read in step S5 is a step indicating the start of machining, the program moves from step S6 to step S13, and executes the machining start subroutine of FIG. 3B. In FIG. 3B, in step S14, the number of times n set to O in the initial setting (step Sl) is incremented. In step 315, it is determined whether the first it measurement value memory Ml is a book.

At the first stage, since * is written in the memory M1 in the initial setting (step S1), the program moves to step S16. In step S16, the correction value is set to 0, and the process returns to the main routine of FIG. 3A.

Next, if the read NC step indicates a machining operation, the program moves from step S7 to step S17. In step 517, the machining operation is performed while making corrections using the correction values set in the machining start subroutine (FIG. 3B). Here, the main shaft 9.degree. 10 rotates at high speed, and a tool (not shown) provided on the turret 11 applies force r to the rotating workpiece. Once the machining operation is complete, the program returns to the main routine.

Next, assuming that the NC step means an unloading operation, the program proceeds from step S9 to step 31.
Move to 8. In step 518, the processed workpiece is transferred to the workpiece unloading conveyor 4 by the gantry loader 2.
will be transported to. In step S19, the measurement device 6 waits for a measurement end signal to be input. During this time, the measurement device 6 accurately measures the size, etc. of the work carried out to the workpiece carry-out conveyor 4. As a result, if the machining error is outside the allowable range, the workpiece is discharged to an NG chute (not shown). When the measurement end signal is issued from the measuring device 6, the program in FIG. 3A moves from step S19 to step S20. In step S20, the value of the second measurement memory M2 is substituted into the first measurement memory Ml. Then, in step 521, the measured value (tolerance) obtained by the measuring device 6 is substituted into the second measured value memory M2. Through these steps S20 and S21, the first measurement value memory Ml
The tolerance of the workpiece obtained in the previous machining is stored in the second measurement value memory M2, and the tolerance of the workpiece obtained in the previous machining is stored in the second measurement value memory M2. When the process in step S21 is completed, the process returns to the main routine.

Note that if an NC step indicating other processing is read, the process moves from step SIO to step S22, and other processing based on the command of the NC step is executed as necessary. When the process in step S22 is completed, the process returns to the main routine.

Machining on the next workpiece is performed in the same manner as the machining on the above-mentioned workpiece. However, when machining the second workpiece, the book is still set in the first measurement value memory Ml, so the determination in step S15 in FIG. 3B remains Yes, and the correction is made in step 516. The value is set to 0. When the machining of this second workpiece is completed, step S20 and step S in FIG. 3A are completed.
At 21, numerical values other than books are assigned to both memories M1 and M2. Therefore, for the third and subsequent works,
The determination at step 515 in FIG. 3B is No, and the process moves to step S23.

In step S23, it is determined whether the actual number of operations n has reached the number of operations N required to reach a stable state. If the determination is NO, the process moves to step S24. Here, it is determined that the device is still in the startup state and has not reached a stable state, so the correction value is 2M2.
+ determined according to (M2-Ml). At this stage, as shown in FIG. 5, rapid thermal displacement is occurring in a fixed direction, but the calculation in step S24 allows an accurate correction amount to be obtained. That is, the tolerance A of the previous time and the tolerance B of the previous time shown in FIG. 4 are respectively stored in the first measurement value memory M.
1 and the value of the second measurement value memory M2.

Then, using the values of both memories Ml and M2, 2M2+(
If a correction value is calculated from 42 Mf), a correction value that is almost close to the tolerance 0 (line X) can be obtained.

Therefore, if machining is performed using this correction value, the tolerance C for the third workpiece becomes almost zero.

On the other hand, after the actual number of operations n reaches the number of operations N obtained experimentally in advance, the determination in step S23 of FIG. 3B becomes Yes, and the process moves to step S25. At this stage, the stage of rapid thermal displacement has passed and the device is in a stable state. Therefore, the correction value is the formula (M1+M2)/
Calculated by 2. This calculation method can eliminate errors with a constant tendency from among various error factors. Using this correction value, step 517 (3rd A
If the machining operation is performed as shown in FIG. 4, the machining can be continued with the tolerance maintained at approximately O, as shown in the right half of FIG.

When the machining progresses and the NC stamp indicating the end of the machining operation is read, the determination at step Sll becomes Yes and the program ends.

Note that as a configuration for determining the timing of transition from a rising state with a large thermal displacement to a stable state, a configuration other than a configuration in which the number of operations obtained experimentally in advance can be input can be adopted. For example, transition to a stable state may be determined by measuring the elapsed time from the initial processing start time. Alternatively, a thermometer disposed within the two-axis lathe l may be used as a sensor, and it may be determined that the transition to the stable state has occurred when the temperature of the thermometer reaches a predetermined temperature or higher.

〔Effect of the invention〕

Since the workpiece processing apparatus according to the present invention is provided with the above-mentioned correction means, it is possible to perform appropriate processing correction in the stand-up state of the apparatus, and accurate processing can be realized.

[Brief explanation of drawings]

Fig. 1 is a schematic front view of one embodiment of the present invention, Fig. 2 is a schematic block diagram of its control section, Figs. 3A and 3B are its control flowchart, and Fig. 4 shows changes in machining tolerance. FIG. 5 is a graph showing changes in thermal displacement in a rising state, and FIG. 6 is a diagram corresponding to FIG. 4 when the correction of the present invention is not performed. 1... 2-axis lathe, 6... Measuring device, 7... Control panel, 9. IO...Main shaft, 11...Turret, 20...Control unit, 25...Machining unit.

Claims (1)

[Claims] (1) A processing section that processes a workpiece, a detection means that detects the tolerance of the workpiece after processing, and calculates the increase in the tolerance based on the detection result by the detection means from the time the device starts up until it stabilizes. A workpiece processing apparatus comprising: a correction means for determining a correction amount from the increase amount and correcting the operation of the processing section using the correction amount.