JPH05185353A - Deflection sensing method for work being chucked - Google Patents

Abstract

PURPOSE:To allow a sensor to avoid colliding with a work due to failure such as mischucking or bad material by establishing an automatic deflection sensing method using a contactless sensor to be executed after a spindle chuck grips the work such as aluminum wheel on which such a requirement is imposed that the deflection of its scale face lies below a certain allowable value. CONSTITUTION:The measuring distance of a contactless sensor 4 is changed at two steps by an air cylinder 6, and at the first step, the sensor 4 is located in a certain position apart from the measuring surface in the nonlinear region of the sensor characteristics to perform measuring any failure such as mischucking, bad material, etc., and a correction is conducted with a correction factor stored previously in a control device 12 for the nonlinear region output of the sensor, and failuere is sensed, and only when no failure, the sensor is located within the normal specification measuring area as the second step to conduct measuring of fine deflections.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for automatically detecting shake by a non-contact type sensor by holding a casting or a black skin material such as casting on a spindle chuck or a mounting jig.

[0002]

2. Description of the Related Art Conventionally, when turning an aluminum wheel for an automobile, for example, as shown in FIG.
The shake of the material 101 gripped in 2 is measured to remove the material having the shake over the allowable value. Since the measurement surface of the aluminum wheel is a black skin, it has many irregularities and is unstable, and measurement by a contact type or optical sensor is difficult. Therefore, the non-contact magnetic sensor 103 is often used. As shown in the graph showing the performance of FIG. 5, the magnetic sensor 103 is specified so that the sensor measurement position (distance) with respect to the measurement surface is within the specified measurement area a within the linear area. The sensor output when the sensor is positioned at a and the aluminum wheel is rotated at a low speed is amplified by the sensor controller 104 and replaced with a distance scale, and the result is compared with an allowable value preset in the control device 105 for determination. Was going on.

[0003]

In the measuring method using the non-contact type sensor 103 described in the prior art, since the sensor is positioned within the specification measuring range a where the measuring distance is relatively short, the measurement is performed. If there is a king miss, material distortion, flash, etc., the maximum deflection of the measurement surface collides with the sensor, making measurement impossible, and in the worst case, the sensor is damaged. The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to prevent a collision by changing the measurement distance step by step with a single non-contact sensor to perform measurement. It is intended to provide a detection method.

[0004]

In order to achieve the above object, a shake detection method at the time of material chucking in the present invention is a non-contact method for detecting the shake of a black skin material chucked on a spindle chuck, an attachment, or a jig. In the method of automatically detecting by a linear sensor, the position of the sensor with respect to the measurement surface of the shake of the black skin material is positioned in a non-linear area beyond the linear area of the sensor performance, and the first measurement is performed. After correcting the sensor output in the non-linear region at the time of measurement, it is compared with a reference value stored in advance to determine whether or not there is an abnormality such as a chucking error or a material defect, and the determination result is no. Only when the sensor is positioned in the linear region, the second measurement is performed, and the sensor output at the time of the second measurement is compared with an allowable value that is stored in advance, and a machining preparation completion signal is output when the value is less than the allowable value. A.

[0005]

In the first step, the sensor is positioned at a distance close to twice the specified distance, and an abnormality such as a chucking error or a material defect is measured. The output is corrected and an abnormality is detected by comparing it with the reference value. Only when there is no abnormality, the sensor is positioned within the specified distance in the second step to measure the fine shake, and stored in advance in the control device. Compared with the allowable value, a machining standard completion signal is output when the allowable value is less than or equal to the allowable value.

[0006]

EXAMPLES Examples will be described with reference to FIGS. On the chuck 2 fitted concentrically with the tip of the main shaft 1 of the lathe, for example, a black leather of an aluminum wheel for automobile (casting)
Material 3 is chucked. An arm 5 having a shake measuring sensor 4 at its tip is fixed to an upper end of a piston rod 8 which is integral with a piston 7 of an air cylinder 6, and the piston 7 is always urged by a spring 9 to project freely. A non-contact type magnetic sensor is used as the sensor 4, and this magnetic sensor can use an amplifier separation type proximity switch ES series made by KEYENCE, etc., and the sensor output is sent to the control device 12 via the sensor controller 11. It is like this.

FIG. 2 is a graph showing the performance of the magnetic sensor 4. According to this graph, when the sensor measurement position, that is, the measurement distance of the sensor 4 is, for example, 5 mm or less, the relationship between the sensor output and the distance changes linearly. Fits in a linear area, 5-10 mm
In between, there is a non-linear region that changes non-linearly. Therefore 5
If the measurement area a of mm or less is used, the change of the magnetic sensor output can be easily replaced by the change of the distance, and this measurement area a is usually designated as the specification measurement area. The output of the measurement range b corresponding to the non-linear region of 5 to 10 mm is obtained by previously obtaining a correction coefficient from the output curve and stored in the control device 12 as a parameter. It becomes possible to replace it with change.

According to the present invention, the measurement area b is a first-step measurement area in which a large shake such as a chucking error or a defective material is symmetrical, and the measurement area a is a second step in which a normal small shake is symmetrical.
Used for each step measurement area. The switching valve 13 is for switching the air supplied to the sensor positioning air cylinder 6, and the solenoid SOL1 is turned on / off by the controller 12.
When SOL1 is turned off, the switching valve 13 is switched to the B position, the front chamber of the air cylinder 6 is communicated with the atmosphere, the piston rod 8 is pushed out by the force of the spring 9, and the sensor 4 is positioned in the first stage measurement area b. , When SOL1 is off, switch to position A,
Air is supplied to the front chamber of the air cylinder 6, the piston rod 8 is pulled in against the force of the spring, and the sensor 4 moves to the second position.
It is positioned in the step measurement area a.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG. In step S1,
The sensor 4 is positioned in the first stage measurement area b, and step S
In 2, the material 3 gripped by the chuck 2 is rotated at a low speed, and an abnormality measurement such as a chucking error or a material defect is performed. In step S3, the output of the sensor controller 11 at the time of measurement is corrected by a correction coefficient stored in advance in the control device 12, and in step S4, an abnormality measurement is performed by comparing with a reference value. Next, in step S5, it is confirmed whether or not there is an abnormality.
In step 6, the rotation of the material is stopped, and in step S7, a material exclusion command is output. If YES in step S5, the sensor is positioned in the second-stage measurement area a in step S8, shake measurement is performed in step S9, and comparison is made with the allowable value stored in advance in the control device 12 in step S10. And step S1
If the value is less than or equal to the allowable value in step 1 and the result is no, the process returns to step S6 to stop the rotation of the material, and step S7 is performed.
A material exclusion command is output at. Step S1
If YES in step 1, the rotation of the material is stopped in step S12, and a processing preparation completion signal is output in step S13.

[0010]

Since the present invention is configured as described above, it has the following effects. The non-contact type sensor is positioned in the non-linear area where the sensing capability is full with respect to the shake measurement surface of the black leather material, and anomalies such as chucking mistakes and material defects are measured. Since it is positioned within the measurement area) to measure the small shake, it is possible to prevent the sensor from being damaged due to a collision in the event of an abnormality, and to correct for the sensor's non-linear area output. The distance range can be doubled or more, and a single sensor can perform multi-step measurement.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a shake detection device according to an embodiment of the present invention.

FIG. 2 is a graph showing the performance of the non-contact sensor used in this example.

FIG. 3 is a flow chart for explaining the operation of the present embodiment.

FIG. 4 is a configuration diagram of a shake detecting device according to a conventional technique.

FIG. 5 is a graph showing performance of a non-contact sensor for explaining a conventional technique.

[Explanation of symbols]

1 Spindle 2 Chuck 3 Material 4 Sensor 6 Air Cylinder 11 Sensor Controller 12 Controller 13 Switching Valve

Claims (1)

[Claims] 1. A method for automatically detecting a shake of a black skin material chucked on a spindle chuck or a mounting jig by a non-contact type sensor, wherein the position of the sensor with respect to a measurement surface of the shake of the black skin material. Is positioned in a non-linear region beyond the linear region of the sensor performance to perform the first measurement, and the sensor output in the non-linear region at the time of the first measurement is corrected and then compared with a reference value stored in advance. Then, the presence / absence of an abnormality such as a chucking error or a defective material is determined, and only when the determination result is absent, the sensor is positioned in the linear region to perform the second measurement, and the sensor at the time of the second measurement. A shake detection method at the time of material chucking, characterized in that an output is compared with an allowable value stored in advance and a processing preparation completion signal is output when the output is less than the allowable value.