JPS6334051A - Automatic measurement/judgment device for defective material and improper chucking - Google Patents

Abstract

PURPOSE:To make it possible to perform a fully automated machining smoothly by providing an NC machine tool such as a turning center with an automatic measurement/judgment device for measuring a misalignment of a work attached to a chuck of the NC machine tool and for judging the work for its properness. CONSTITUTION:In a turning center, a measurement device 44 for measuring a misalignment of a work W is arranged either on the periphery or on the end surface of the work W. The measurement device 44 is connected via an input-output circuit 45. A robot device 25 is also provided for attaching/ detaching the work W to/from a chuck 7. Further, a reject judgment device 48 is connected to a central processing unit (CPU) 30. The judgment device 48 consists of a measurement maximum minimum determination means 49 for determining the maximum or minimum value of various measurements of the measurement device 44, an operation means 50 for calculating a difference between the maximum and minimum values, a judgment means 51 for comparing the operated result with a preset tolerance value, and an abnormality coping means 71 for commanding a machine tool with such a process as a re-checking the work based on a count number of abnormalities.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is designed to detect material defects and chucking defects to determine material defects and chucking defects in order to fully automatically process a workpiece with an NC machine tool. This invention relates to an automatic measurement discrimination device.

[Conventional technology]

Conventionally, when machining a workpiece with an NC machine tool, the robot grips the workpiece from the workpiece feeder, attaches it to the spindle chuck, and removes it, then predetermined machining is repeated for each workpiece based on the NC machining program and automatic machining is performed. It is being said.

[Problem that the invention seeks to solve]

However, when processing a hardened workpiece among the workpieces to be processed, the workpiece itself is deformed at the time of hardening. Therefore, when processing a hardened workpiece by attaching it from a workpiece feeder to the spindle chuck using a robot, etc., the attachment of the workpiece to the chuck may be defective, or even if the attachment of the workpiece to the chuck is normal. If the workpiece itself is defective, the workpiece will run out during processing, resulting in a defective product no matter how well the workpiece is processed.

Therefore, the operator constantly monitors the situation in which the workpiece is attached to the chuck, and if there is any wobbling of the workpiece, the worker adjusts the chuck or decides to replace the workpiece itself and performs the specified processing, so there is no problem. When machining is performed fully automatically, defective products occur due to workpiece runout, leading to a decline in production.

The present invention has been proposed in view of the above circumstances and to solve the problem. When processing a workpiece with an NC machine tool, the present invention is to feed the workpiece from the workpiece feeder and perform the processing fully automatically. Automatic measurement and discrimination device for material defects and chucking defects that makes it possible to eliminate machining defects by measuring the deflection of the workpiece attached to the chuck and determining whether the workpiece is normal or not, and identifying material defects and chucking defects. Our goal is to provide the following.

[Means and operations for solving the problems] In order to solve the above problems, the present invention provides a main spindle, a chuck provided at the tip of the main spindle to grip the workpiece, and a processing or measuring device provided for the main spindle. An automatic machine tool that processes a workpiece by relative movement of the main spindle and the tool rest, and includes a speed control means for controlling the workpiece and a rotational angular displacement control means for controlling the workpiece. A robot device for supplying the chuck, a measured value minimum/maximum value determining means for determining the minimum value or maximum value of the measured value of the measuring device, and a calculation means for calculating the difference between the maximum value and the minimum value, and the calculation method. Judgment means that compares the calculation results of the means with tolerance setting values stored in memory in advance to determine whether it is normal or abnormal, counts abnormalities, regrips the workpiece based on the number of abnormalities, removes defective workpieces, supplies primary workpieces, The present invention is characterized by comprising a failure determination device having an abnormality response means for instructing a robot device or an automatic machine tool to at least one of stopping the automatic machine tool and outputting an alarm.

By adopting the above configuration, when a workpiece is attached to the chuck, it is measured and determined whether the workpiece itself is normal or whether the attachment to the chuck is normal, and the chuck or the chuck can identify and deal with defective materials or chucking defects. This can be done fully automatically by controlling a robot device or the like.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

(1) First, an outline of a machine tool to which the device of the present invention is used will be explained.

FIG. 2 is a plan view of the turning center, particularly showing a state in which a work feeder device is also attached.

In FIG. 2, a column 2 is erected on a bed 1, and a headstock 4 is attached to the column 2.

The rotation of the motor 5 is transmitted to the headstock 4 to the pole screw of the circuit, and the headstock 4 is slid in the Y-axis direction (vertical direction) along the guides 3, 3 via the nut of the circuit. The main shaft 6 is rotated by the rotation of the main shaft motor 8 transmitted through a belt wound around pulleys 9 and 10 . A chuck 7 is attached to the tip of the main shaft 6, and a work W is gripped by the chuck 7, and the work W is rotated to perform turning processing. A spindle position indexing device M is attached to the rear end of the spindle 6, and can index the angular position of the workpiece W. (Hereinafter, the angle indexing axis of the main shaft will be referred to as the C-axis.) On the other hand, a saddle 12 is placed on the bed 1, and the motor 1
The rotation of the guide 11.5 is transmitted to the pole screw 17.
The saddle 12 is slid along LL in the Z-axis direction. A cross slide 14 is placed on the saddle 12, and a universal table 19 is attached to the cross slide 14. The rotation of the motor 16 is transmitted to the pole screw 18, and the tool rest 19 is slid along the guide 13.13 in the X-axis direction.

An indexing rod 20 that can be indexed by 90 degrees is attached to the tool rest 1g, and the tool can be indexed in both the X-axis direction and the Z-axis direction. Further, an automatic tool changer 21 is mounted on the tool post 19, and the automatic tool changer ff121
A tool magazine 22 for storing a plurality of tools is provided on the top. A twin arm for automatically exchanging tools is attached to the automatic tool changer 21 so that it can move back and forth (in the X-axis direction) and rotate 180 degrees.

In response to the tool exchange command, the tool box 1-22a in the exchange position of the tool magazine 22 is lifted up to a horizontal position, and the twin arms of the circuit rotate to insert the tool and the tool bot in the X-axis direction of the indexing head 20. The tool inserted into the tool pot 22a is grasped, the tool is pulled out from the indexing head 20 and the tool pot 22a, and the tool is rotated 180 degrees to perform automatic tool replacement.

The indexing head 20 is indexed in the X-axis direction (referred to as the fixed side) and is used for mainly turning tools, and indexed in the X-axis direction (referred to as the rotating side) and used mainly for milling. The tool to be applied is inserted. Indexing in the X-axis direction and the two-axis directions is performed by an indexing motor 20a.

Further, when the tool in the X-axis direction performs milling, the main shaft of the indexing head 20 is rotated by the motor 23.

A work feeder device 24 is installed in front of the turning center to feed the workpiece, and between the turning center and the workpiece feeder device 24, a receiver of the workpiece feeder device 24 feeds the workpiece W from the transfer position 24a to the tip of the main spindle 6. A robot device 25 is provided for transferring to the attached chuck 7. This robot device has vertical movement, movement in the direction of the main axis, and rotational movement of the arm.

The workpiece feeder device 24 places the workpieces W to be processed on an endless pallet (circuit) connected at regular intervals, rotates the pallet, and transports the workpiece W to be processed to the delivery position 24a.

The robot device 25 grips and lifts the workpiece W at the delivery position with the robot hand 25a, and then rotates to capture the front surface of the chuck 7. The workpiece W held by the robot hand 25a is transferred to the chuck 7, and after the workpiece W is gripped by the chuck 7, the robot device 25 is moved backward in the X-axis direction and moves to a standby position. Next, the work W held by the chuck 7 is subjected to predetermined turning and milling.

Before machining the workpiece, the device of the present invention measures the runout of the workpiece W attached to the chuck 7, and if it is correct, the workpiece is machined.

(2) Next, the configuration of the apparatus for automatically measuring and determining material defects and chucking defects according to the present invention will be explained. FIG. 1 is a block diagram of one embodiment of the present invention.

In FIG. 1, each element constituting the present invention is connected to the central processing unit 12cPLJ30 via a path line 31 as follows.

First, a keyboard with a screen 32 for inputting and outputting information necessary for the present invention is connected via an interface 33. The information is stored in memories 34, 35, and 36 as a program, a measurement program, and a robot operation program.
are connected so that they are stored respectively. In order to perform processing based on the above-mentioned machine program, the tool post 19 or the main spindle 6
X.

X respectively to drive in the Y and X axis directions.

The Y and X axis motors 16.5.15 are connected via an interpolator 37 and an amplifier 38. The main shaft 6 is rotated by a motor 8 for processing or measurement, and the motor 8 is connected via a motor frequency converter 39 and an amplifier 40 in order to control the speed and rotation angle position at this time. . A chuck 7 for attaching the workpiece W is attached to the tip of the main shaft 6, and a cylinder 41 for opening and closing the chuck 7 is attached to the rear end, and a pressure valve 42 is connected to the input/output circuit 4 to open and close the cylinder 41.
Connected via 3. A measuring device 4 is provided on the outer periphery or end face of the workpiece W to measure the deflection, etc. of the workpiece W.
4 is provided, and the measuring device 44 is connected via an input/output circuit 45.

Further, a robot device 25 is provided to attach and detach the workpiece W to the chuck 7, and drive motors 25b, 25c, and 25d of the robot device 25 are connected via an interface 46 such as R3232C and a programmable controller 41 for controlling the robot. It is connected. moreover,
A defect determination device 48 is connected to the central processing unit CPtJ3G. The defect determination device 48 includes a measured value minimum/maximum determining means 49 for determining the minimum value or the maximum value of various measured values of the measuring device 44, and an arithmetic means for calculating the difference between the maximum value and the minimum value. 50, a determining means 51 that compares the calculation result and the tolerance setting value and determines whether it is normal or abnormal, counts abnormalities, regrips the workpiece based on the number of abnormalities, removes the defective workpiece, and supplies the primary workpiece; It is comprised of an abnormality response means 71 that instructs the robot device or the automatic machine tool to at least one of stopping the automatic machine tool and outputting an alarm. The measurement value minimum/maximum determining means 49 includes:
The touch signal emitted by the measuring device 44 and the turret 19 at that time
A measurement value register 53 is used to input the measurement value obtained by importing the machine coordinate position of
) 54.55 and the value of the measurement value register 53 is inputted via the OR gate 56.57, the minimum reference value register 58 and the large quantity reference value register 59, the values of the second and subsequent measurement value registers 53, and the measuring signal. Comparison value register 61 into which the value of measurement value register 53 is input via AND gate 55
, the value Ai of the comparison value register 61 and the values AOI, A of the minimum reference value register 58 and maximum reference value register 59.
Comparators 62 and 63 for comparing O2, respectively, and the comparator 62
．． 63 and the condition signal from the comparison value register 61, data A Il is passed through AND gates 64 and 65.
It consists of a minimum value register 66 and a maximum value register 67 in which i n +A+max is stored on one side, and the minimum value As1n and maximum value Amax stored in the minimum value register 66 and maximum value register 67 are the or game) 56
．． 57 via minimum or maximum reference value register 58.59
The system is configured such that the minimum or maximum reference value A01°AO2 is set again and sequentially compared with the data input from the next measurement register 53 to determine the minimum value Am1n and maximum value Awax. When the comparison of all the measured values is completed, the measurement end signal and the signals from the minimum value register 66 and maximum value register 67 are used to generate an ant game) 68.
69 is opened, and the minimum value Am1n and maximum value A wax are input to the next calculation means 50. The calculation means 50 calculates the difference F (F=A@ax) between the minimum value A+min and the maximum value A@ax.
ax-Amin). Then, the maximum value Amax and the minimum value A of the calculation results are
The difference F between m1n is input to the next determining means 51.

The determining means 51 determines the maximum value Amax and the minimum value Awi.
It is composed of a comparator that compares the difference F of n with the tolerance setting value Δl of the tolerance setting memory 72, and if the difference F is larger than the tolerance setting value Δl, it is NG (abnormal), and if it is smaller, it is OK (normal). , and when the result is NG, this NG is counted as the counter 70.70'.

70", 1 for 1 workpiece.
At the time of the second measurement (Kn = 1. = 1), a program to regrip the workpiece is commanded, and at the time of the second measurement for one workpiece (Kn = 2. = 2), the workpiece is Remove,
A program is issued to attach a new workpiece to the chuck. A new workpiece is measured, and the first measurement is N.
In the case of G (Kn = 3. = 1), a re-gripping program is commanded, and the second NG (Kn = 4. = 2).
The alarm means 52 is activated. It should be noted that if the measurement is OK, a cannibal program is commanded. The alarm means 52 has two
When each workpiece fails continuously, an alarm is emitted by sound or light, and the machine is stopped along with the alarm.

Note that the counters 70 and 70' count NG for each workpiece. These counters 70, 70', 70', alarm means 52, etc. constitute abnormality response means 71 of the present invention.

The defect determination device 48 described above may be configured as a peripheral device of the CPU 30 connected to the CPU bus 31;
3 It may be configured so that it is inherent in Q as a means of using i.

Next, the basic principle of the present invention will be explained.

FIGS. 3(a) to 3(d) are explanatory diagrams for explaining the basic principle of the present invention. In FIGS. 3(a) to 3(d), each indexing head 20 has touch sensors Ts■ and Ta■.
is installed. On the other hand, a workpiece W to be machined is gripped by the main shaft 6 via a chuck 7. Before the workpiece W gripped by the chuck 7 is subjected to predetermined processing, the touch sensor Ts■ or Ts■ attached to the indexing head 20
Then, as shown in FIGS. 3(b) to 3(d), the diameter and length of the end surface of the workpiece W are measured by contacting the outer diameter surface or end surface of the workpiece W. As for the data to be measured, the main axis 6 is indexed at a certain angle and measurements are taken at 6 to 24 locations, and from the obtained measurement data, maximum and minimum measurement data such as large measurement data Amax and minimum measurement data As1a are obtained. is extracted, and the difference F (Amax −Aa+in ) is compared with the tolerance Δ2 of a preset allowable range. 1 (For example, when measuring the workpiece W of 1!j for the first time, (Ao+ax −Aa+
in ) > 8i, that is, if it is NG, chuck the workpiece W again and measure again, and the second time is also NG.
When the workpiece W becomes G, the workpiece W is not subjected to the predetermined processing and is replaced with another workpiece W. If the first measurement of the next new workpiece is NG and the second measurement is also NG, an alarm will be issued and the machine will be stopped. This is to let you know.

The operation of the present invention will be explained based on the flowchart of FIG. In FIG. 4, when the apparatus of the present invention is started, the work W attached to the chuck 7 is removed by the hand 25a of the robot device 25 in the 0th stage and returned to the work feeder device 24, and then the hand 25a of the robot device 25 25a is the delivery position 24a of the work feeder device 24.
The work W for next processing placed on the machine is grasped, transferred into the machine, and attached to the chuck 7. At the 0th stage, the touch sensor Ts attached to the indexing head 20 of the tool rest 19 is made to touch the outer diameter surface of the workpiece W for next processing held by the chuck 7 to measure runout. Since it is possible to measure the run-out of the workpiece W for the next processing at a maximum of 24 locations, it is possible to select and measure as appropriate. For example, if you want to measure six points, you can index the main axis 6 by 60 degrees to obtain radius measurements at six points. In the 0th stage, the maximum Amax and minimum Am1n are extracted from the six measured values, and from the preset tolerance Δl, (Amax - Am1
Runout is determined whether n)≦△l.

If (Amax - Amin)≦Δ2 is not satisfied at the 0th stage, the first time is NG, and at the 0th stage, the workpiece W is once removed from the chuck 7, and then re-chucking is performed by attaching it to the chuck 7 again. Returns to the program before stage 0. Next, as in the previous case, the runout is measured at the 0th stage, and the runout is determined at the 0th stage. In the shake judgment of the 0th stage (A
If w + ax − Amin )≦△l, the second N
G, and it is determined whether or not two consecutive workpieces W are NG in the 0th stage. In this case, since it is still the second NG with only one workpiece W, proceed to stage 0, remove the workpiece W with the hand 25a of the robot device 25, and then remove the workpiece W with the hand 25a of the robot device 25.Furthermore, in the stage 0, the robot device 25 removes the second workpiece Attach the workpiece to chunk 7, measure and judge the runout at the 0th stage and 0th stage as before, and if the first time is NG, the 0th stage
Re-chucking the workpiece in the 0th stage and 0th stage again.
Run-out measurement and run-out determination are performed in the stage, and if the second time is NG, the process proceeds to the 0th stage, where it is determined whether two workpieces are NG in succession. In this case, two workpieces are consecutively
Since it is G, an alarm is generated, the NC machine tool is stopped, and the abnormality is inspected. In the 0th stage (A wax-Amin
)≦2, it is not NG but OK, so the process proceeds to the 0th stage and predetermined processing is performed. Therefore, unless two consecutive workpieces to be machined fail, the predetermined machining is automatically performed continuously.

〔effect〕

When machining a workpiece with an NC machine tool, the present invention examines whether the workpiece itself is normal or whether the chuck installation is normal in order to feed the workpiece from the workpiece feeder and perform the machining fully automatically. Since it is possible to detect material defects or chucking defects through measurement and judgment, it is possible to perform the specified processing fully automatically without producing defective products and without human intervention. Therefore, by employing the device of the present invention, unmanned processing can be performed.
As a result, it has the effect of improving the operating rate and productivity by several orders of magnitude compared to the conventional method.

[Brief explanation of drawings]

FIG. 1 is a control block diagram showing the configuration of the present invention. FIG. 2 is a plan view of a turning center in which the apparatus of the present invention is used. FIGS. 3(a) to 3(d) are explanatory diagrams for explaining the basic principle of the present invention. FIG. 4 is a flowchart illustrating the present invention in detail. 5... Motor 6... Spindle 7... Chuck 8... Spindle motor 15, 16... Motor 19... Turret post 20... Indexing head 21... Automatic tool changer 23 ...Motor 24...Work feeder device 25...Robot device 30...CPU 34...Cannibal program memory 35...Measurement program memory 36...Robot operation program memory 48...
Defective determination device 49...Measurement value minimum/maximum value determination means 50...Calculation means 51...Judgment means 52...Alarm means 71...Abnormality response means Patent applicant Hitachi $Ii Machine Co., Ltd. Agent Person Patent Attorney Michizo Isono 84J-Ob-1 Figure 4

Claims (1)

[Claims] A main spindle, a chuck provided at the tip of the main spindle that grips the workpiece,
In an automatic machine tool that has speed control means and rotation angle position control means for machining or measurement provided for the main spindle, and that processes a workpiece by relative movement of the main spindle and the tool post, the runout of the workpiece is measured. a robot device for feeding the workpiece to the chuck; a measurement value minimum/maximum value determining means for determining the minimum value or maximum value of the measurement value of the measurement device; A calculating means for calculating the difference, a determining means for comparing the calculation result of the calculating means with a tolerance setting value stored in memory in advance and determining whether it is normal or abnormal, and a determining means for counting abnormalities and re-gripping the workpiece based on the number of abnormalities. Material defects characterized by comprising a defect determination device having an abnormality response means for instructing a robot device or an automatic machine tool to perform at least one of the following: removing a workpiece, supplying the next workpiece, stopping an automatic machine tool, and outputting an alarm. , an automatic measurement and determination device for chucking defects.