JPS606824A - Origin circuit - Google Patents

Abstract

PURPOSE:To improve precision by adjusting the timing of a selection signal and detecting the coincidence with an origin reference signal, and selecting the output signal of an origin detector with the current selection signal and position detection signal and generating an origin position signal. CONSTITUTION:An object of measurement such as the cutting tool of a machine tool is moved relatively to a scale, and the movement is slowed down near an origin position and stopped the moment a light emitting diode LZDS turns on. At this time, the output signal ZDS of the origin detector 11 is generated to set a flip-flop circuit FF2. The light emitting diode LGP turns on at the stop position. When the object of movement is further moved, an AND circuit AND1 outputs the origin selection signal C, which is supplied to the clock terminal CK2 of the filp-flop circuit FF2. An accurate origin position signal ZGL is sent from the Q2 terminal of the FF2 to an output terminal 0 at the position (real origin).

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an origin circuit, in particular, to a scale of the position detector that combines a position detector and an origin detector used for controlling the tool position of a machine tool, etc. The present invention relates to an improvement in means for adjusting the generation point of an origin position signal in an origin detection circuit which selects an origin position signal in response to the output of an origin detector from a selection signal whose generation timing is variable within an interval of grid points.

BACKGROUND ART AND PROBLEMS Conventionally, when using a position detection device, such as a magnetic scale device, to read the tool position of a machine tool, etc., a highly accurate origin detector is used to detect the origin.

The on-off No. 414 is used as the origin position signal (・.However, in a numerical control device, for example, a resolver,
A commonly used method is to use the inductor as an inductor position detection device, select its lattice point signal based on the output of the origin detector, and use it as the origin position signal. In this case, since the pitch of the lattice points of the 5-position detector is long (2N), a combination of a dog and a limit switch is used as the origin detector, and the lattice point selection signal is generated from the switch.

On the other hand, even when used as a position detection device such as the above-mentioned Roku2ki scale device, since more accurate weight reading is required these days, the origin output type in the numerical control device described above is adopted. This is being considered.

However, in such a position detection device, since the grid point pitch of the magnetic scale is as short as 0.2 g, a high-precision switch with a built-in magnetoresistive element is used as the origin detector, and the grid point signal is determined by the output of the switch. must be selected.

Moreover, in order to enable highly accurate selection of grid point signals, J:
It is necessary to set the record high speed switch so that it is turned on at the center of the lattice point pitch. This is because if the selection signal (switch output) is obtained at the center of the grid point pitch, even if the selection signal generation position shifts by half of the maximum grid point pitch due to some disturbance, the highly accurate grid point signal can be used as the origin position signal. Because you can.

However, is the above selection signal at the center of the grid point pitch? As described above, it is very difficult to mechanically and precisely finely adjust the set position of the high-precision switch because the lattice point pitch is very short as described above.

OBJECTS OF THE INVENTION Accordingly, it is an object of the present invention to provide an origin circuit that does not require mechanical fine adjustment of the set position of an origin detector.

Another object of the present invention is to provide an origin circuit which can electrically adjust the generation timing of a selection signal selected based on the output signal of an origin detector and the origin position.

Still another object of the present invention is to provide an origin point system using a phase modulation type magnetic scale device as a position detector.

SUMMARY OF THE INVENTION In order to achieve the above object, the origin circuit of the present invention periodically detects the position according to the relative movement with the object to be measured. a selection signal generating means for generating a selection signal with variable stop timing within the interval of the grid points for each grid point of the scale of the position detector; An origin reference signal generating means for generating an origin reference signal at the required foot position timing within the interval; and a detection middle stage for detecting coincidence with the origin reference signal by adjusting the timing of the selection signal; The present invention also includes an origin position selection means for selecting the output signal of the origin detector according to the detection number A and the position 1a to generate an origin position signal.

Particularly, the circuit of the present invention is a position detector using a phase modulation method having an ion scale, wherein the M selection signal generating means selects the reference signal having a different frequency image from the position detector. When configured to generate a selection signal, it is suitable as an origin circuit capable of electrically adjusting the origin position by 1 ν degrees.

Embodiment FIG. 1 is a block diagram showing the configuration of the main part of the position detection circuit used in the phase modulation type magnetic scale device.
■ is a magnetic scale, 2 is g1% l channel head,
3 is a second channel e-head, 4 is an oscillator, 5 is a frequency reduction circuit, 6 is an excitation circuit, 7 is a phase shifter, 8 is a mixer amplifier circuit, 9 is a band pass filter, 10 is a limiter amplifier,
Reference numeral 11 denotes an official origin checker 11+, such as the above-mentioned high-precision switch, installed near the origin position. Oscillator 4 output signal (reference signal) KEFO, oscillator output angular frequency GE0
, when the output of the step-down circuit is f o /2, f6
= sin ω(t, and the output (phase modulation signal) of the limiter amplifier IO is 1 if the lattice point pitch of the scale is λ and the relative displacement amount YX with respect to the scaled head is 1, then 5=sin(ω.t +−E− !!-x)λ.

Section 2 shows the configuration of an embodiment of the origin circuit according to the present invention.
In the circuit diagram, FFI and FF2 are flip Floran circuit IM
, INVI ~ INV3 Binvar 7 circuit, LGP.

LZDS and LZGS are light emitting diodes, 8ND
J~^ND3 is an AND circuit, MM is a monostable S full chip bibrator circuit, and T is a digital selection circuit.

The digital selection circuit '■' includes multiple switches 81 to Sn.
, exclusive OR circuits EX1 to EXn and AND circuit AN
D3, etc., and the frequency e of the position detection circuit and the reference signal f□xnfO having a different frequency from the numerical reduction circuit 5 are applied to one of the circuits EX, ~EXn, and the other input is connected to the switch S. ]~SnY is grounded, and the output of each exclusive OR circuit is connected to an AND circuit AND3yr-
It is connected to one side of the AND circuit ANDI through the AND circuit ANDI.

A phase modulation signal S is given to the DI terminal of the flip-flop circuit FFI and the input of the seven-nostable multivibrator circuit MM, and the output of the circuit MM is sent to the AND circuit.
The output of the AND circuit is connected to the other input of the inverter circuit INVI and the light emitting diode L
Connected to PG.

The input of the AND circuit AND2 is connected to the phase modulation signal S and the flip-flop circuit FF1 to the output of the AND circuit AND3.
0) The output from the Q1 terminal is leaked, and the output C of AND2 is connected to the terminal CK2 of the flip-flop circuit FF2.

The output signal ZDS of the origin detector] l is sent to the D2 terminal of the flip-flop circuit FF2 and to the inverter circuit.
are sent to the light emitting diode LZDS through V2￥,
The Q2 terminal of FF2 is connected to the light emitting diodes J and ZGS through the inverter circuit INV;3't- and to the output terminal 0.
are connected to (・ru.

In the digital selection circuit T, the switches Sl to Sn are binary switches that can be turned on and off in a binary manner, and by appropriately selecting and turning on these switches, the output of the AND circuit ΔND3 (to the selection signal ) can adjust its generation timing within the interval f of the lattice points of the scale.Furthermore, the monostable multivib break circuit MM responds to the phase modulation signal S to adjust the timing at a predetermined position IM within the lattice point interval as shown in Fig. 8g3. Timing (e.g. center)
The output signal (origin reference signal B) is generated.

Now, when the object to be measured, such as the tool for work 6a4, is moved 41 rows with respect to the scale and comes near the origin position, the above movement is performed slowly until the light emitting diode LZDS lights up. The movement is stopped the moment the light emitting diode LZDS lights up, and at this time, the output signal ZDS of the origin detector 11 is generated and the flip-flop circuit FF27 is set.

At the above stop position, select switches 81~Sn to appropriate white and turn them on so that light emitting diodes I and UP light up.
Ru. At this time, the selection signal Δ coincides with the origin reference signal B as shown in FIG. 4 (al), and therefore is set at the center of the grid point interval.

Next, when the object to be measured is moved further from the above-mentioned stopping position,
The relative positional relationship between the selection signal set as described above and the phase modulation signal S is as shown in FIG.
Clock terminal CK2 of fritsuno flop circuit FF2
K% can be increased. Therefore, at this position (Xf) origin) F'
An accurate origin position signal ZGL IJ'' is sent to output terminal 0 from the Q2 terminal of F2.

Note that the generation of the origin position signal may be confirmed using a light emitting diode LZG, but this is not essential.

Furthermore, the present invention is not limited to the above embodiments, but can be applied, for example, to cases in which the selection signal is matched to the position of a gate signal having a predetermined width, such as that created by a window comparator or the like.

As is clear from the detailed description of the invention, according to the present invention, it is possible to obtain an origin position that accurately corresponds to the true origin position, and moreover, it is possible to obtain a value for the origin position that accurately corresponds to the true origin position. Since the generation timing of the selection signal can be adjusted electrically and digitally, there is no need for meticulous fine adjustment of the origin detector. Therefore, the accuracy of the origin detector does not necessarily have to be high.

It is particularly suitable for cases where the lattice point pitch is narrow, such as in magnetic scales.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a position detection circuit, FIG. 2 is a block diagram showing an embodiment of the present invention, and FIGS.
FIG. 1a)* (bJ is a waveform diagram for the operation theory of the above embodiment. ■...Magnetic scale, 2, 3...Head, 11
...Origin detector. Procedural amendment deadline date 1, February 1982, Case indication 1982 Patent Application No. 114088 3 Person making the amendment Relationship with the case Patent applicant Address Name Name Sony Magne School Co., Ltd. 4 Agent 〒10
5 Address: Shiba 3-chome Building 5, 3-2-14 Shiba, Minato-ku, Tokyo
Target of amendment (1) Lines 15 to 17 of page 6 of the present specification are amended as follows. "It is an origin detector. If the output signal of the step-down circuit 5 is > 4, and its angular frequency is the blade." (2) Ibid.
Correct to. (3) Change UANDIJ, page io, line 4 of the same book to “AND2J
Correct to. (4) Same page, line io r L Z GJ to rLZGsJ
Correct to. (5) Correct figures 1 and 2 as shown in the attached sheet.

Claims (1)

[Claims] +1) A position detector that periodically generates a position detection signal in response to relative movement with the object to be measured, an origin detector installed near the origin position of the relative movement, and selection signal generating means for generating a selection signal whose generation timing is variable within the interval between the grid points for each grid point of the scale of the detector; and generating an origin reference signal at a predetermined position timing within the grid point interval from the position detection signal. a detection means for detecting coincidence with the origin reference signal by adjusting the timing of the selection No. 48; An origin circuit characterized by comprising an origin position signal selection means for selecting an output (g) and generating an origin position signal. 2. The origin circuit according to claim 1, wherein the selection signal generating means comprises a digital selection circuit that digitally selects a reference signal having a different frequency pattern from the position detector. The digital selection circuit includes a nucleic acid switch and a plurality of exclusive OR circuits to which the switch and the reference signal having different frequencies are respectively input. One origin circuit.