JPH02275314A - Inductosyn substrate - Google Patents

Abstract

PURPOSE:To enhance the sensitivity of a displacement sensor and to make it possible to make the substrate compact by determining the number of paths of coil patterns which are arranged on an inductosyn substrate alternately as two outgoing and returning paths or more. CONSTITUTION:Two coil patterns 11 and 12 are formed with copper foils through an insulating film on a metal plate on an inductosyn substrate at a scale part. Sine wave currents in a phase A and a phase B whose phases are shifted by 90 degrees to each other are conducted through said patterns. The similar pattern is provided on the side of another slider. The patterns 11 and 12 are formed along two outgoing and returning paths (4 paths) alternately. Therefore, a useless region in the displacement direction can be decreased to 33 - 20% in comparison with conventional one path. As a result, the arranging density of the coil patterns becomes large, the output power of the coil pattern on the side of the slider is increased and the detecting sensitivity of the displacement sensor can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to an inductosin substrate used in a displacement sensor that detects displacement using an electromagnetic induction method.

(Summary of the Invention) This invention increases the sensitivity of the inductosin board and enables miniaturization by increasing the number of passes of each coil pattern, through which sine waves having phases different by 90 degrees are energized, to two or more round trips. be.

(Prior art and its problems) As is well known, the inductosyn board used in a displacement sensor that detects displacement by electromagnetic induction has a slider part that follows the detection target and a scale part that is fixed to the sensor body. Provided on both sides.

As shown in Fig. 3, the inductosyn board normally used for the scale part has two coil patterns 31 and 32 formed thereon, and these coil patterns 31 and 32 have an A phase and a B phase that are 90 degrees out of phase with each other. A sine wave current is applied, and the other slider section is configured to detect the generated magnetic field as a sine wave whose phase is shifted according to the amount of displacement.

By the way, the inductosin substrates of the scale part are 9
A sinusoidal current with a phase shift of 0 degrees is applied, and as shown in the figure, coil patterns 31 and 32 formed perpendicular to the displacement direction are alternately formed one round trip at a time.

This reciprocating part has the same pitch P of the coil patterns similarly formed at equal intervals on the other slider part, that is, the line spacing is 1/2P, and each coil pattern has the same phase in the displacement direction. Further, the phases of the coil patterns 31 and 32 are shifted by 1/4P from each other. Therefore, a blank space is created between both coil patterns. Since a coil pattern cannot be formed in this margin, it is a wasted area in the displacement direction. In the figure, compared to the case where coil patterns are virtually formed at equal intervals over the entire surface of the board, the ratio of wasted area is as much as 33%, and the inductosin board itself is made into a shape corresponding to that amount. There's a problem.

(Objective of the Invention) This invention was made to solve the above problems, and its purpose is to reduce the ratio of wasted areas and increase the arrangement density of coil patterns in the displacement direction. The purpose of the present invention is to provide an inductosin substrate.

(Structure and Effects of the Invention) In order to achieve the above object, the present invention provides that sinusoidal currents that are 90 degrees out of phase with each other and that are 1
The invention is characterized by an induct thin board in which two coil patterns having a phase shift of /4 pitch are formed and arranged alternately in the displacement detection direction, and the number of passes of the alternatingly arranged coil patterns is two or more each. do.

In this invention, as described above, coil patterns each having two or more reciprocating passes are formed alternately, so the arrangement density of the coil patterns in the displacement direction increases, and the sensitivity of the inductosyn board increases accordingly. At the same time, miniaturization becomes possible.

As a result, a compact and high-performance displacement sensor can be realized using this inductosyn substrate.

(Example) Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a pattern diagram showing the inductosin substrate of the first embodiment.

The inductosin substrate 1 used in the scale section shown in the figure has two coil patterns 11 and 12 formed of copper foil on a metal plate with an insulating layer interposed therebetween. These coil patterns 11 and 12 are coil patterns similarly formed at equal intervals on the other slider section (not shown), to which sine wave currents of phase A and phase B, which are 90 degrees out of phase with each other, are energized. is the same as the pitch P, that is, the line spacing is 1/2
P, and each coil pattern is formed with the same phase in the displacement direction, and furthermore, the phases of coil patterns 11 and 12 are shifted from each other by 1/4P.

Here, the coil patterns 11 and 12 formed perpendicularly to the displacement direction on the inductosin substrate 1 alternately make two reciprocations (four
By forming each pass), the wasted area in the displacement direction is narrower than in the past. In the figure, compared to the case where coil patterns are virtually formed at equal intervals over the entire surface of the substrate, the ratio of areas where no pattern can be formed is reduced to 20%.

FIG. 2 is a pattern diagram showing the inductosin substrate 2 of the second embodiment.

In this case, the coil patterns 21 and 22 are formed with a larger number of passes than in the first embodiment, and as shown in the figure, the coil patterns 21 and 22 are formed alternately in three round trips (six passes).
Compared to the case where coil patterns are virtually formed at equal intervals over the entire surface of the board, the ratio of areas where no pattern can be formed is 1.
reduced to 4%.

Furthermore, as a third embodiment (not shown), if the number of passes of the coil pattern is set to four round trips (eight buses), the ratio of the area where no pattern can be formed is reduced to 11%.

In this way, by increasing the number of passes of coil patterns that are alternately formed, the ratio of areas where no pattern can be formed can be gradually reduced.

As a result, the ratio of wasted areas has decreased, and the arrangement density of the coil patterns in the displacement direction has increased, increasing the output of the coil pattern on the slider side, improving the S/N ratio, and improving the detection accuracy of the displacement sensor. It becomes possible to improve.

Similarly, since the dimension of the inductosyn substrate itself in the displacement direction is shortened, it is also possible to downsize the displacement sensor using the inductosyn substrate.

[Brief explanation of drawings]

FIG. 1 is a pattern diagram showing an inductosyn board according to the first embodiment of the present invention, FIG. 2 is a pattern diagram showing an inductosyn board according to the second embodiment, and FIG. 3 is a conventional example. It is a pattern diagram. 1.2...Inductosin board

Claims (1)

[Claims] 1. Sine wave currents that are 90 degrees out of phase with each other are energized, and two coil patterns that are 1/4 pitch out of phase with each other are arranged alternately on an inductor thin board that is formed and arranged alternately in the displacement detection direction. The inductosin board is characterized in that the number of passes of the coil pattern is two or more round trips or more.