JPS61265268A - Grinding abnormality detection device - Google Patents

Abstract

PURPOSE:To permit an accurate detection of an oscillated grinding state by providing a constitution that a grinding state detection means produces a decision signal after removing only an output signal corresponding to a hole by a removing means. CONSTITUTION:Every time a grinding stone 10 grinds a workpiece 3, an eddy current sensor 9 detects non-contactingly an oscillated grinding state of the surface to be ground 1 of the workpiece 3. A lubrication hole detection unit 12 detects an output signal corresponding to a portion of a lubrication hole 2 of the workpiece 3 and a lubrication hole masking unit 11 operates to remove the output signal corresponding to the lubrication hole 2 so that only an oscillated grinding signal is taken out. The grinding signal is applied to a grinding state detection means 14. A detection decision unit 16 compares and decides an amplitude and a period of the oscillated grinding signal and the decision signal are sequentially applied to a following detection decision temporary memory 17. When a workpiece completes one rotation, an oscillation signal is erased and a value detected at a final grinding process is produced from the memory 17 through a detection decision unit 20.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a grinding abnormality detection device that detects an abnormal state of grinding when, for example, a crankshaft portion of a crankshaft is ground with a grindstone.

(Prior art) Conventionally, a chatter grinding state caused by clogging (loadinQ) of the grinding wheel of the crank bin portion of the workpiece, that is, a grinding state in which the finished surface of the workpiece is corrugated in an uneven manner due to micro vibrations, has been detected. As the grinding detection means, for example, there is a means using an eddy current sensor.

This grinding detection means using an eddy current sensor detects eddy current induced in a conductor by changes in magnetic field, and converts this current change into a voltage change. ffi to detect the chatter grinding state.

However, the above-mentioned crank bin part has an oil hole, and when detected by the eddy current sensor mentioned above, the sensing level drops significantly in this performance part, and the grinding state can be erroneously detected due to oil filling. However, there were some problems that could arise.

(Object of the Invention) The present invention provides a grinding abnormality detection device that can accurately detect chatter grinding conditions by removing the output signal corresponding to the hole portion of the rigid material as described above. purpose.

(Structure of the Invention) The present invention comprises a sensor for detecting the chattering grinding state of a workpiece, and a hole detection means for detecting a signal output from a hole in a workpiece surface using an output signal from the sensor. ,
A canceling unit that cancels only the output signal of the hole output from the sensor using the output signal from the hole detecting unit, and a determination signal is output by comparing the value of the signal output from the canceling unit with a set value. The present invention is characterized in that it is a grinding abnormality detection device comprising a grinding state detection means.

(Effects of the Invention) According to the present invention, after only the output signal corresponding to the hole is removed by the above-mentioned canceling means, the grinding state detecting means outputs the determination signal, so that the chatter grinding state can be accurately detected. It has the effect of

(Example) An embodiment of the present invention will be described in detail below based on the drawings.

The drawing shows a grinding abnormality detection device, and in the drawing, a crankshaft crank bin portion (hereinafter simply referred to as a workpiece) 3 of a crankshaft as a workpiece having an opening 2 on a workpiece surface 1 is shown.
is supported by the tip 5 at the tip of the first work rest 4 arranged on the virtual X coordinate axis and the tip 7 at the tip of the second work rest 6 arranged on the virtual Y coordinate axis, and is supported in the axial direction of the work 3. Both ends are held by chucking means (not shown) and supported to rotate at a predetermined speed of 60 to 12 Orpm in the direction of the arrow.

Further, each of the first and second work rests 4.6 described above is attached to the grinding machine main body 8, and one of the second work rests 6 is equipped with an s current sensor 9 that electrically detects the chatter grinding state of the work 3. It is installed.

This eddy current sensor 9 is attached to the above-mentioned second work rest 6 in a state of being inclined at, for example, 45 degrees with respect to the work 3, and when the work 3 is pressed by hydraulic pressure during grinding, it follows the assistance of the work 3. Since it is integrated with the work rest 6, the separation distance between the work 3 and the sensor 9 is smaller than that of the work 3.
The structure is such that chatter grinding conditions can be stably detected without being adversely affected by the vibrations of the work rest 6 and the work rest 6.

Processed surface 1 of the above-mentioned workpiece 3 arranged in this way
For example, a grinding wheel 10 is provided opposite to the grinding wheel 10 whose high rotational speed can be adjusted for each of four processes: rough finishing, first fine finishing, second Fi'i finishing, and final finishing.

At the output stage of the eddy current sensor 9 mentioned above, there is a performance masking PI.
S11 and the cuff hole detection section 12 are connected.

This sleeve hole detection unit 12 is a circuit that detects a signal output by the demonstration 2 of the workpiece surface 1 of the workpiece 3 using the output signal from the eddy current sensor 9 described above, and corresponds to the demonstration 2 and generates a so-called valley signal. Detects the falling pulse-like signal output as .

The above-mentioned armhole masking section 11 is a circuit that removes only the output signal corresponding to the hole 2 portion output from the above-mentioned eddy current sensor 9 based on the output signal from this armhole detection section 12. It is constituted by a diode clip circuit including a hole 2 or a hold circuit that holds an output signal corresponding to the hole 2 portion.

A grinding state detection means 14 is connected to the output stage of the armhole masking section 11 via a bandpass filter 13.

This grinding state detection means 14 is the aforementioned sleeve hole masking section 1.
This means compares the value of the signal output from 1 with a set value and outputs a judgment signal, and in this embodiment, it is constituted by a chatter width detection section 15 at the front stage and a chatter detection judgment section 16 at the rear stage.

The chatter width detection section 15 described above outputs an electric signal in which the amplitude of the output signal after passing through the band pass filter 13 corresponds to the size of the actual grinding unevenness on the surface to be processed 1, and the chatter width detection section 15 compares the amplitude of the output signal of the chatter width detection unit 15 with the electric pA quasi-value (set value) corresponding to the actual grinding unevenness of the workpiece surface 1, for example, 2μ, outputs a judgment signal, and also calculates the amplitude of the output signal from the period of the output signal. Converting the number of peaks of the signal waveform to 1,
A determination signal is output by comparing with a preset reference period (set value), and for example, if the grinding unevenness is 2 μ or more and the number of peaks in the signal waveform is 5 to 41, it is determined that chatter grinding is occurring.

A detection and determination temporary storage section 17 is connected to the next stage of the chatter detection and determination section 16 .

This temporary storage section 17 is applied with an output from a workpiece one rotation detection section 18 connected to the next stage of the armhole detection section 12, and at the time of the final finish grinding process, an input terminal 19 of a chatter detection start signal is applied.
When a chatter detection start signal is input to the workpiece one rotation detection section 18 from
When the rotation is detected and the chatter detection start signal is turned off, the detection value during the final grinding process is outputted from the detection judgment temporary storage section 17 via the detection judgment output section 20 at the next stage, and this output is used for example on a monitor. It is configured to work.

The illustrated embodiment is constructed as described above, and its operation will be explained below.

Each time the workpiece 3 is ground by the grinding wheel 10, the chatter grinding state of the processed surface 1 of the workpiece 3 is detected in a non-contact manner by the aforementioned eddy current sensor 9.

The output signal corresponding to the part of performance 2 of the above-mentioned war 93 is detected by the armhole detection section 12, and the armhole masking section 11 operates to cut the output signal corresponding to this performance 2.

Since this armhole masking section 11 uses, for example, a diode clip circuit or a hold circuit that cuts out only the upper part of the signal waveform, all the signals corresponding to Performance 2 are cut off, and only the chatter grinding signal is extracted.

The chatter grinding signal thus extracted is outputted to the grinding state detection means 14 of the next stage after a noise component corresponding to a so-called attenuation band outside the band is removed by a band pass filter 13 of the next stage.

In this grinding state detection means 14, the amplitude of the chatter grinding signal is converted into an electric signal corresponding to the size of the actual grinding unevenness by the chatter width detection section 15 in the preceding stage, and outputted. The amplitude and period of the signal are compared and determined by the chatter detection/determination section 16 at the subsequent stage, and these determination signals are sequentially output to the detection/judgment temporary storage section 17 at the subsequent stage.

Such grinding of workpiece 3 is rough finishing, 1st M finishing,
When the final work, F grinding process, is reached after the second fine finishing, when the same start signal is input from the chatter detection start signal input end 19 to the workpiece one rotation detection section 18, this workpiece one rotation detection section 18 is activated. is started, one revolution of the workpiece 3 is detected at the time when the armhole 2 is detected by the armhole detector 12, and by turning off the chatter detection start signal, the above-mentioned detection judgment temporary storage section 17 is controlled, and this temporary storage section 17 The detected value during the final grinding process is outputted via the detection determination output section 20 at the next stage.

In other words, since only the output signal corresponding to the demonstration 2 can be removed by the armhole masking section 11, there is an effect that the chatter grinding state can be accurately detected.

Regarding the correspondence between the structure of this invention and the above-mentioned embodiments, the workpiece of this invention corresponds to the workpiece 3 of the embodiment, and similarly, the hole corresponds to the performance 2, and the sensor corresponds to the eddy current sensor 9. Correspondingly, the hole detecting means corresponds to the armhole detecting section 12, and the releasing means corresponds to the armhole masking section 11, but the present invention is not limited to the configuration of the above-described embodiment.

[Brief explanation of drawings]

The drawing is a system diagram of a grinding abnormality detection device showing an embodiment of the present invention. 1... Surface to be machined 2... Oil Hole 3... Work 9... Eddy current sensor 11... Armhole masking section 12... Armhole detection section 14... Grinding state detection means

Claims (1)

[Claims] 1. A grinding abnormality detection device for detecting a chatter grinding state in grinding a workpiece having a hole opened in the workpiece surface, which electrically detects the chatter grinding state of the workpiece. a hole detection means for detecting a signal output by a hole in a workpiece surface using an output signal from the sensor; and a hole output signal output from the sensor using an output signal from the hole detection means. A grinding abnormality detecting device comprising: a canceling means for canceling only the abnormality of the grinding condition; and a grinding state detecting means for comparing the value of a signal output from the canceling means with a set value and outputting a determination signal.