JPS5856401B2 - Sizing device for non-round workpieces - Google Patents

Description

Detailed Description of the Invention The present invention provides a sizing device for a non-perfect circular workpiece that measures the dimensions of a non-perfect circular workpiece being processed and outputs a sizing signal when the dimension reaches a predetermined value. relates to a sizing device for non-circular workpieces that uses a sampling circuit to catch changes in the highest or lowest point of a pulsating measurement signal.
The purpose of this is to automatically change the sampling timing according to changes in the pulsation period of the measurement signal, so that even if the pulsation period changes, the measurement signal at the highest or lowest point is always sampled. Another object of the present invention is to eliminate the need to switch the sampling timing using a signal sent from a high-voltage circuit or the like in response to changes in the rotational speed of the workpiece.

Generally, when measuring the dimensions of a workpiece that has a discontinuous machined surface, such as a spline shaft, the measurement signal pulsates at a frequency that corresponds to the rotational speed of the workpiece. , it is necessary to capture the change in the highest or lowest point of the measured signal.

To catch such changes in the highest or lowest point of a pulsating measurement signal, there is a method that uses a peak value detection circuit that detects the peak value of the measurement signal, and a method that detects the peak value of the measurement signal when it reaches the highest or lowest point. There is a method of sampling the measurement signal, but when measuring the dimensions of a non-circular workpiece such as a spline shaft, the measurement feeler bounces at the rise of the groove and the measurement signal is reflected by the arrows in Figure 3 a, l). Since a parasitic peak as shown in A occurs, it is more accurate to capture the highest point using a sampling method that can avoid capturing such a parasitic peak as the highest point by changing the sampling timing. It is possible to measure dimensions.

However, when using the sampling method, changes in the highest or lowest point of the measurement signal cannot be detected unless the sampling timing is changed according to the rotation of the workpiece, and changes in the rotational speed of the workpiece cannot be detected. Therefore, the parasitic peak generated by the rise of the filler may be taken as the highest point, making it impossible to perform accurate measurements.

For this reason, in the past, a switching signal was sent from a high-voltage circuit as the rotational speed of the workpiece was changed, and the sampling timing was switched in response to this switching signal.

Therefore, in the past, it was not only necessary to provide a circuit to send the switching signal to the high-voltage circuit, but also a signal line to transmit the switching signal from the high-voltage circuit to the sizing device. , the wiring of high-power circuits has become complicated, and it is also necessary to install sampling pulse generation circuits that output sampling pulses at different timings in a number corresponding to the number of switching speed stages within the sizing device, as well as a switching circuit to switch between them. This also has the drawback that the circuit of the sizing device becomes complicated.

The present invention has been made in view of these conventional drawbacks, and includes a period detection circuit for detecting the pulsation period of the measurement signal inside the sizing device, and a period detection circuit that detects the pulsation period of the measurement signal. This method is characterized in that the timing of sampling is changed.

Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, reference numeral 1 denotes a measuring head, and on the outer frame 1a of this measuring head 1, a feeler 10.
is pivoted.

A spring 11.11 is stretched between the feeler 710.10 and the outer frame 1a, and applies a force toward the center of the workpiece W to the contact portions 10a, 10a of the feeler 10.10.

Also, at the right end of the feeler 10.10, a movable core 12.
12 is fixed, and the displacement of this movable core 12.12 is detected by a detection coil 13.13.

Further, oil dampers 14, 14 are provided between the filler 10.10 and the outer frame 1a to apply an appropriate braking force.

The oscillation circuit 2, the amplification circuit 3, and the synchronous rectification circuit 4 together with the measurement head 1 constitute a measuring means. When an AC voltage is applied from the oscillation circuit 2 to the detection coil 13.13, the detection coil 13.13 An alternating current signal having a magnitude corresponding to the movement of the filler 10.10 is output.

This alternating current signal is given to the amplifier circuit 3, amplified, and then synchronously rectified by the synchronous rectifier circuit 4. The synchronous rectifier circuit 4 outputs a pulsation signal with a period corresponding to the rotational speed of the workpiece W as shown in FIG. 3a. A measurement signal with .

The sample hold circuit 5 samples and outputs the measurement signal at the highest point of the measurement signal output from the periodic rectifier circuit 4. When the rotational speed of the workpiece W changes and the pulsation period of the measurement signal changes, The sampling timing is changed accordingly, so that the measurement signal is sampled at the highest point of the measurement signal, regardless of changes in the pulsation period of the measurement signal.

Therefore, even when the rotational speed of the workpiece W is switched from high-speed rotation to low-speed rotation, the sample-and-hold circuit 5 outputs a signal representing the change in the highest point of the measurement signal, as shown in Figure 3. Ru.

The determination circuit 6 converts the signal output from the sample hold circuit 5 into a set voltage VS1. In comparison with VS2, when the signal output from the sample hold circuit 5 exceeds the set voltage VS1, the first sizing signal AS1 is output, and when it exceeds the set voltage VS2, the second sizing signal AS2 is output. There is.

In this embodiment, the set voltage VS1 is set so that the first sizing signal AS1 is output when the dimensions of the workpiece e7W reach the dimensions that complete rough grinding, and the second sizing signal is output when the dimensions of the workpiece W reach the finishing dimensions. VS2 is set, and when the first sizing signal AS1 is sent from the sizing device, the unillustrated heavy-duty circuit performs fine grinding by reducing the rotational speed of the workpiece W to, for example, half that of rough grinding, and performs second sizing. The processing is stopped when the sizing signal AS2 is sent out.

Therefore, it is determined whether the workpiece W has reached the rough grinding completion dimensions while the workpiece W is rotating at high speed, and whether the workpiece W has reached the finishing dimension is determined when the workpiece W is rotating at low speed. It will be done when the

Further, the signal outputted from the sample hold circuit 5 is also applied to a display 7, and the dimensions of the workpiece W being processed are displayed.

FIG. 2 shows a specific circuit configuration of the sample-and-hold circuit 5, in which the measurement signal given from the measuring device is given to the non-inverting terminal 1 of the operational amplifier OPI and also given to the square wave generation circuit 20. It has become.

The circuit constituted by the operational amplifier OP1 constitutes a voltage follower circuit with an amplification degree of 1, and the signal output from the operational amplifier OP1 is applied to the capacitor C1 via an analog game (AG).

Therefore, when the analog gate (AG) is opened, a voltage corresponding to the measurement signal is charged to the capacitor C1 and sampling is performed, and when the analog gate ()AG is closed, the sampled measurement signal is stored and held.

Then, the voltage of this capacitor C1 is outputted via an operational amplifier OP2 that constitutes a voltage follower circuit.
Give it to the discrimination circuit 6.

Note that the resistor R connected between the drain terminal of the analog game LAG and the gate terminal G and the diode controller connected to the gate terminal are auxiliary resistors for opening and closing the analog game LAG. In the circuit, when the potential on the cathode side of diode DI reaches 15V, the analog gate (AG) closes, and when the potential on the cathode side reaches +15V, the analog gate (AG) opens.

The square wave generating circuit 20 extracts only the pulsating component of the measurement signal and outputs a square wave having the same period as the extracted pulsating waveform in synchronization with the pulsating waveform, as shown in FIG. 3C.
A square wave signal whose period changes in accordance with a change in the pulsation period of the measurement signal is output.

The square wave signal output from this square wave generation circuit 20 is
A period detection circuit 21 detects the period length of the square wave signal and outputs a DC signal proportional to the period length, and a rise detection circuit 22 detects the rise of the square wave signal. The period detection circuit 21 outputs a detection signal proportional to the length of the pulsation period as shown in FIG. 3d, and the rise detection circuit 22 outputs a detection signal proportional to the length of the pulsation period as shown in FIG. A timing signal synchronized with is output.

The sampling pulse generation circuit 23 normally applies a voltage of 15V to the diode DI to close the analog gate (AG), and detects whether a timing signal is given from the rise detection circuit 22 or output from the period detection circuit 21. After a time proportional to the magnitude of the signal has elapsed, a +15V sampling pulse is sent out for a certain period of time to open the analog gate AG, thereby storing the measurement signal in the capacitor C1.

The time d from when the timing signal is given until the sampling pulse is output is proportional to the magnitude of the detection signal output from the period detection circuit 21, but this proportionality constant is determined by the pulsation period of the measurement signal. Adjustment is made so that the measurement signal is always sampled after the bounce of the filler 10.10 has ceased, even if the change in temperature has changed.

Therefore, as shown in FIG. 3f, the timing at which the sampling signal is output from the sampling pulse generation circuit 23 is delayed as the pulsation period of the measurement signal becomes longer. The highest point value that avoids the parasitic peak due to the jump of .10 is reliably sampled.

Therefore, even if the rotational speed of the workpiece W changes, the dimensions of the workpiece W can be accurately measured.

In the above embodiment, the outer diameter of the spline shaft is measured, but the inner diameter of the spline hole that fits into the spline shaft may be measured.

In this case, a fall detection circuit for detecting the fall of the square wave may be provided in place of the rise detection circuit 22, and the timing signal output from this fall detection circuit may be given to the sampling pulse generation circuit 23. .

Furthermore, the sizing device of the present invention can not only be used to measure the dimensions of the mountain portion of a spline, but also
As long as the rotation of the workpiece causes pulsations in the measurement signal, it is possible to accurately measure the dimensions of workpieces of different shapes, as long as they are not perfectly circular.

As described above, in the sizing device for non-perfect circular workpieces of the present invention, the sizing device includes a period detection circuit for detecting the pulsation period of the measurement signal, and a period detected by the period detection circuit. This is because a sampling pulse generation circuit is provided that outputs sampling pulses at different times according to changes in the pulsation period, and samples the highest point value of the measurement signal, avoiding parasitic peaks due to bounce of the filler, regardless of changes in the pulsation cycle. As the rotational speed of the workpiece W is changed, a switching signal is given from the high-voltage circuit to the sizing device, so that the rotation of the workpiece W is controlled even if the sampling timing is not switched by the given switching signal. It can respond to changes in speed and can accurately measure dimensions regardless of the rotational speed of the workpiece.

Therefore, not only is it unnecessary to provide a circuit for generating a switching signal in the high-voltage circuit, but also a signal line for transmitting the switching signal to the sizing device is not required, and the high-voltage circuit is simplified.

In addition, there is no need to provide timing pulse generation circuits that generate sampling pulses at different timings in the sizing device in a number corresponding to the number of switching stages of the workpiece rotation speed.
The circuit configuration of the sizing device is also simplified.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the sizing device for non-circular workpieces according to the present invention, FIG. FIG. 3 is a timing chart showing operating waveforms of each part of the sample and hold circuit 5. In FIG. 1...Measurement hand, 2...Oscillation circuit,
3... Amplifier circuit, 4... Periodic rectifier circuit, 5... Sample hold circuit, 6...
・Discrimination circuit, 1010...Tween, 13...
...Detection coil, 20...Square wave generation circuit, 21...Period detection circuit, 22...Rise detection circuit, 23...Sampling pulse Generation circuit, AG...analog gate, C1...
・・・Capacitor, DI・・・Diode, OP
I, OP2... operational amplifier, R...
Resistance, W... Workpiece.

Claims (1)

[Claims] 1 Measuring means for measuring the dimensions of a non-perfect circular workpiece, a gate to which a measurement signal sent out from the measuring means and pulsating at a period corresponding to the rotational speed of the workpiece, and a measurement signal given through this gate. a timing signal generation circuit that detects the rise or fall of the measurement signal and outputs a timing signal; and a period detection circuit that detects the pulsation period of the measurement signal and outputs a detection signal according to the pulsation period. circuit, and when a time period corresponding to the magnitude of the detection signal output from the period detection circuit has elapsed after the timing signal is output from the timing signal generation circuit, a sampling pulse is sent to the gate to activate the gate. A sampling pulse generation circuit that is opened for a predetermined period of time and causes the storage means to store the measurement signal at the highest or lowest point of the measurement signal that pulsates regardless of changes in the rotational speed of the workpiece, and the measurement signal stored in the storage means. A sizing device for a non-circular workpiece, comprising a determination circuit that compares the measured voltage with a set voltage and outputs a sizing signal when the measured voltage matches the set voltage.