JPH07243843A - Size inspection method of work - Google Patents

Abstract

PURPOSE:To automatically discriminate whether work size is within a tolerance and efficiently perform inspection work of work size in a short time. CONSTITUTION:A work W is sandwiched between a pair of inspection arms movably supported in the direction wherein they are in contact with a body frame 3 and is separated and quality of work size is inspected. A numerically controlled and torque-controlled electric motor 13 connected to each inspection arm is driven, the inspection arms are in contact with each other once and a distance measurement means is reset. The electric motor is driven reversely, each inspection arm is moved to a preset open origin position and a distance up to the open origin position is measured with the distance measurement means. Next, each inspection arm is moved toward the work W from the open origin position and brought into contact with it. another distance up to a contact position is measured with the distance measurement means, measured distance data is compared with size data of the preset work and it is judged that the work size is within a rule in the case where its error is within preset allowable error data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a milling machine,
The present invention relates to a work size inspection method for inspecting the quality of a work size when processing the work in various machine tools such as a lathe and a polishing machine.

[0002]

2. Description of the Related Art As a conventional method for inspecting the quality of a work, a measuring instrument such as a caliper or a micrometer is used for the work, and the measured value read is within a predetermined error range. The quality of the workpiece is inspected based on whether or not there is any.

However, the above-mentioned conventional inspection method is a method in which the worker presses the measuring instrument against the work for each inspection work and reads the numerical value to inspect the quality of the work, so the work efficiency of the inspection is poor. It was Further, in this inspection work, it took a long time to read the numerical values, and the inspection workability was extremely poor.

The present invention has been invented to solve the above-mentioned conventional drawbacks, and its purpose is to automatically determine whether or not the work size is within a predetermined tolerance range. Another object of the present invention is to provide a work dimension inspection method capable of performing inspection work efficiently and accurately in a short time.

[0005]

Therefore, according to the present invention, a work is pinched between a pair of inspection arms which are movably supported by a main body frame so as to move toward and away from each other. In the inspection method, after driving the electric motors connected to the respective inspection arms and capable of numerical control and torque control, the inspection arms are brought into contact with each other once to reset the distance measuring means, and then the electric motors are reversely driven. Then, each inspection arm is moved to a preset open origin position, and the distance measuring means measures the distance to the open origin position, and then each inspection arm is moved toward the workpiece from the open origin position and abutted. At the same time, the distance measuring means measures the distance to the contact position, and the distance data measured by the distance measuring means is compared with the preset dimension data of the work, and the error is calculated. The preset range of tolerance data are characterized by determining the work dimension is within the prescribed.

[0006]

Since the present invention is constructed as described above,
Prior to dimensional inspection of the workpiece, the electric motor is driven to bring the inspection arms into contact with each other and the count value of the distance measuring means is reset, and then the electric motor is driven in reverse to separate the inspection arms from each other. Move to position. Next, after arranging the work between the inspection arms, drive the electric motors to move the inspection arms in the directions in which they come close to each other to bring them into contact with the work and until each inspection arm comes into contact with the distance measuring means. To measure the distance. Then, the distance data measured by the distance measuring means is compared with preset work dimension data, and if the error is within the preset error data range, it is determined that the work dimension is within the specified range. .

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the method of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, the main body frame 3 of the inspection machine 1 is made of metal and is formed into a rectangular flat plate, and support portions 5 are attached to the left and right ends thereof, respectively.
Further, rails 7 are attached to the main body frame 3 located below the supporting portions 5 so as to extend in the longitudinal direction.

A feed screw 9 is rotatably supported between the support portions 5 and 5 via bearings 11 and 11, and the main body frame 3 is provided at an end portion of the feed screw 9 located on one support portion 5 side. A direct-current or alternating-current servomotor 13 capable of performing numerical control and torque control, which is attached to, is connected via an installment ring (not shown). In addition, the servo motor 1
A position detecting device 15 is connected to the rotating shaft of 3. As the position detecting device 15, a light detecting method in which a light emitting member and a light receiving member are arranged with a disk having a large number of slits formed according to the position detecting resolution, or a large number according to the position detecting resolution on the outer peripheral surface side is provided. Any of the magnetic detection methods in which the magnetic detector is arranged on the disk of the permanent magnet on which the pole teeth are formed. The bearings 11 may be ball bearings or needle bearings.

Bilaterally symmetrical inspection arms 17 and 19 are supported on the rail 7 via linear guide members 16 and 18 so as to be movable in the longitudinal direction, and the inspection arms 17 and 19 are also provided.
Nut members 21 and 23 that mesh with the feed screw 9 are attached to the unit 19. These nut members 21 and 23 have mutually reverse nut structures, and move the inspection arms 17 and 19 in directions away from or close to each other in accordance with the forward rotation or reverse rotation of the feed screw 9. Incidentally, contact plates 25 and 27 are attached to the facing surfaces of the inspection arms 17 and 19, respectively.

In FIG. 3, the CPU 31 includes a setting unit 33.
Are connected, and the setting section 33 is provided with a numerical key 33a and a display device 33b. Then, the numerical data 33a is used to input and set the dimension data of the work W, the open origin position data of the inspection arms 17 and 19, the deceleration start position data of the inspection arms 17 and 19, the error data of the work W, and the display device 33b. Each data is switched and displayed.

The CPU 31 has a ROM 35 and a RAM 37.
, And various program data for inspecting the dimensions of the work W are stored in the ROM 35. In addition, in each storage area of the RAM 37, distance data from the closed position where the inspection arms 17 and 19 are in contact with each other input by the numerical key 33a to the open origin position separated by a predetermined distance, the dimension data of the work W, The allowable error data of the work W, the deceleration start position data for moving the separated inspection arms 17 and 19 at a high speed in a direction of approaching each other, and then switching to a low speed movement, and the like are stored.

A position detection device 15 is connected to the CPU 31, and position detection signals are sequentially input from the position detection device 15 in accordance with the rotation of the feed screw 9 driven by the servo motor 13. Further, a distance counter 39 as a distance measuring means is connected to the CPU 31, and the count value of the distance counter 39 is counted up or down based on the position detection signal from the position detection device 15. Furthermore,
A drive control circuit 41 is connected to the CPU 31, and a servo motor 13 is connected to the drive control circuit 41.
Then, the CPU 31 outputs various drive signals corresponding to the high speed and the low speed, the tightening torque, and the maximum allowable torque to the drive control circuit 41 to drive the servo motor 13 at the respective rotation speeds and torques.

Next, a method of inspecting the work size by the inspecting machine 1 configured as described above will be described.

First, when a power switch (not shown) is turned on, when the CPU 31 inspects the size of the work W in step 51 in FIG. 4 to FIG. 7, an operator resets the zero reset switch (not shown). It is determined whether or not a zero reset signal has been input by turning ON. Now, in order to start the dimension inspection of the workpiece W, when the zero reset signal is input and the determination in step 51 is YES, the CPU 31 causes the block 53 to drive the drive control circuit 41.
A predetermined tightening torque and a high-speed drive signal are output to drive the servomotor 13 to rotate. The tightening torque is appropriately set to, for example, a torque at which the workpiece W to be inspected is not plastically deformed. And servo motor 1
The inspection arms 17 and 19 are moved in a direction in which they approach each other in accordance with the rotational driving of 3, and the position detection signal from the position detection device 15 is input to the CPU 31.

Then, the CPU 31 determines in step 55 whether or not the inspection arms 17 and 19 are in contact with each other.
If the inspection arms 17 and 19 are not in contact with each other, the position detection signal is continuously input from the position detection device 15, and the CPU 31 determines that step 55 is NO and returns to step 55. On the contrary, the position detection device 15
It is determined that the inspection arms 17 and 19 have come into contact with each other based on the fact that the position detection signal from is not input for a predetermined time. Then, the CPU 31 determines YES in step 55, after resetting the count value of the distance counter 39 to "0" in block 57, and then in step 59 determines whether or not an open command signal is input. Then, if the determination in step 59 is YES, the CPU 31 determines in block 61.
Outputs a tightening torque and a high-speed reverse rotation drive signal to the drive control circuit 41 to drive the servomotor 13 in the reverse direction to move the inspection arms 17 and 19 to the open origin position and detect the position from the position detection device 15. The distance counter 39 is sequentially incremented based on the signal.

The CPU 31 refers to the count value of the distance counter 39 in step 62 and checks the inspection arm 17 ...
19 It is determined whether or not each other has been returned to the open origin position.
Now, the inspection arms 17 and 19 are moved to a position at a predetermined distance from the centers of contact with each other, and the distance counter 3
When the count value of 9 coincides with the open origin position data stored in the RAM 37, the CPU 31 stops driving the servo motor 13 by the block 63 to stop the inspection arms 17 and 19 at the open origin position and outputs an open completion signal. To do.

Next, as shown in FIGS. 8 to 10, when the workpiece W to be inspected is placed on the main body frame 3 between the inspection arms 17 and 19 which are separated from each other, the CPU 31 inspects in step 65. It is determined whether the instruction signal is input. As the inspection instruction signal, the inspection arm 17.1.
9 A method in which an operator turns on the clamp start switch to output an inspection instruction signal after the work W is placed on the main body frame 3 between them, or a limit switch, a photodetector, or the like is placed at the place where the work W is placed. Any method may be used in which a work detector or the like is provided and an inspection instruction signal is output when the work W is placed.

When the work W is placed on the body frame 3 between the inspection arms 17 and 19 and the inspection instruction signal is input and the determination in step 65 is YES, the CPU 31 allows the servomotor 13 by the block 67. The inspection arms 17 and 19 are driven to rotate at maximum torque and high speed, and the inspection arms 17 and 19 are moved at high speed in a direction in which they approach each other. Then, the CPU 31 sequentially counts down the distance counter 39 based on the position detection signal from the position detection device 15 with the movement of the inspection arms 17 and 19 and refers to the count value of the distance counter 39, and the count value is stored in the RAM 37. When it coincides with the stored deceleration start position data, the block 69 outputs a tightening torque and a low speed drive signal to the drive control circuit 41 to rotationally drive the servo motor 13 and move the inspection arms 17 and 19 at a low speed. Let

It should be noted that each inspection arm 1 up to the deceleration start position.
The servomotor 13 is drive-controlled so as to move 7/19 at the maximum allowable torque and high speed, but the servomotor 13 is drive-controlled so as to move each inspection arm 17/19 at the above-mentioned tightening torque and high speed. You may.

Next, in step 73, the CPU 31 determines whether or not the inspection arms 17 and 19 moving at a low speed contact the work W. When the inspection arms 17 and 19 are not in contact with the workpiece W, the low speed movement of the inspection arms 17 and 19 is continued and the position detection signals from the position detection device 15 are sequentially input. Become NO. On the contrary, when the inspection arms 17 and 19 come into contact with the work W, the movement is stopped and the position detection signal from the position detection device 15 is not input for a predetermined time. Therefore, the determination in step 73 is YES. . And step 7 above
If 3 is YES, the CPU 31 compares the doubled value obtained by subtracting the count value of the distance counter 39 and the distance data to the open origin position in step 75 with the dimension data stored in advance, and the error is found. It is determined whether it is within the range of the allowable error data stored in advance.

For example, when a foreign substance such as cutting dust adheres to the work W and the dimensional error is equal to or larger than the predetermined value of the allowable error data, the CPU 31 performs an alarm process in block 77. As the alarm processing method, a buzzer is sounded, an alarm lamp is turned on to notify the operator that the size of the work W is equal to or more than the allowable error, or after the operator is notified, the process returns to the block 59 described above. Servo motor 13
Is driven in reverse to move the inspection arms 17 and 19 to the open origin position.

On the contrary, if the dimensional error of the work W is within the predetermined value, the determination in step 75 is YES, so C
The PU 31 outputs a normal inspection signal in block 79 to determine that the size of the work W is good, and then executes step 5
Returning to step 9, the servo motor 13 is reversely driven to separate the inspection arms 17 and 19 from each other and the inspection operation is completed.

In the above description, the servo motor 13
Although the feed screw 9 is connected to the rotary shaft of (1) by a coupling, the rotary shaft and the feed screw may be integrally formed on the rotor of the servomotor 13.

[0025]

As described above, according to the present invention, it is possible to automatically determine whether or not the work size is within a predetermined allowable error range and perform the inspection work efficiently and accurately in a short time.

[Brief description of drawings]

FIG. 1 is a partially omitted perspective view of an inspection machine as viewed from the back side.

FIG. 2 is a front view of the inspection machine.

FIG. 3 is an electrical block diagram of a control device.

FIG. 4 is a flowchart showing a closing operation of zero reset.

FIG. 5 is a flowchart showing an opening operation of zero reset.

FIG. 6 is a waveform diagram showing a relationship between each signal waveform and a motor torque and a motor rotation speed at the time of a closing operation at the time of zero reset.

FIG. 7 is a waveform diagram showing a relationship between each signal waveform at the time of opening operation at the time of zero reset and the motor torque and the motor rotation speed.

FIG. 8 is a flowchart showing an inspection operation.

FIG. 9 is a flowchart showing an inspection operation.

FIG. 10 is a waveform diagram showing the relationship between each signal waveform during the inspection operation and the motor torque and the motor rotation speed.

[Explanation of symbols]

 1 Inspection Machine 1 3 Body Frame 13 Servo Motor as Electric Motor 15 Position Detection Device 17 Inspection Arm 19 Inspection Arm W Work

Claims (3)

[Claims] 1. A method for inspecting the quality of a work by sandwiching a work between a pair of inspection arms that are movably supported in a direction in which they come into contact with and separate from each other on a main body frame, and are connected to each of the inspection arms. After driving the electric motors capable of numerical control and torque control, the inspection arms are once brought into contact with each other to reset the distance measuring means, and then the electric motors are reversely driven to open each inspection arm in advance. While moving to the origin position, the distance measuring means measures the distance to the open origin position, and then each inspection arm is moved from the open origin position toward the workpiece and brought into contact with the distance measuring means to the contact position. The distance is measured, the distance data measured by the distance measuring means is compared with the preset workpiece dimension data, and the error is within the preset allowable error data range. Dimensional inspection methods work and judging a workpiece dimension is within the prescribed for. 2. When the inspection arms are moved toward the work, the electric motors are drive-controlled so as to move the inspection arms to the front position of the contact position with respect to the work with the maximum allowable torque and high speed, and then the front side. 2. The work size inspection method according to claim 1, wherein the electric motor is drive-controlled so that each inspection arm is moved at a tightening torque and a low speed after the position. 3. A method for inspecting a work dimension according to claim 2, wherein the tightening torque is set to a torque at which the work is not plastically deformed.